Merge branch 'dev'

CHANGELOG

@@ -1,6 +1,9 @@
 proxy更新日志
 v4.1
-1.优化了http(s),socks5代理中的域名智能判断,如果是内网IP,直接走本地网络,提升浏览体验.
+1.优化了http(s),socks5代理中的域名智能判断,如果是内网IP,直接走本地网络,提升浏览体验,
+ 同时优化了检查机制,判断更快.
+2.http代理basic认证增加了对https协议的支持,现在basic认证可以控制所有http(s)流量了.
+
 
 v4.0
 1.内网穿透三端重构了一个multiplexing版本，使用github.com/xtaci/smux实现了tcp链接的多路复用，

Godeps/Godeps.json

@@ -0,0 +1,133 @@
+{
+	"ImportPath": "proxy",
+	"GoVersion": "go1.8",
+	"GodepVersion": "v79",
+	"Packages": [
+		"./..."
+	],
+	"Deps": [
+		{
+			"ImportPath": "github.com/alecthomas/template",
+			"Rev": "a0175ee3bccc567396460bf5acd36800cb10c49c"
+		},
+		{
+			"ImportPath": "github.com/alecthomas/template/parse",
+			"Rev": "a0175ee3bccc567396460bf5acd36800cb10c49c"
+		},
+		{
+			"ImportPath": "github.com/alecthomas/units",
+			"Rev": "2efee857e7cfd4f3d0138cc3cbb1b4966962b93a"
+		},
+		{
+			"ImportPath": "github.com/golang/snappy",
+			"Rev": "553a641470496b2327abcac10b36396bd98e45c9"
+		},
+		{
+			"ImportPath": "github.com/pkg/errors",
+			"Comment": "v0.8.0-6-g602255c",
+			"Rev": "602255cdb6deaf1523ea53ac30eae5554ba7bee9"
+		},
+		{
+			"ImportPath": "github.com/templexxx/cpufeat",
+			"Rev": "3794dfbfb04749f896b521032f69383f24c3687e"
+		},
+		{
+			"ImportPath": "github.com/templexxx/reedsolomon",
+			"Comment": "0.1.1-4-g7092926",
+			"Rev": "7092926d7d05c415fabb892b1464a03f8228ab80"
+		},
+		{
+			"ImportPath": "github.com/templexxx/xor",
+			"Comment": "0.1.2",
+			"Rev": "0af8e873c554da75f37f2049cdffda804533d44c"
+		},
+		{
+			"ImportPath": "github.com/tjfoc/gmsm/sm4",
+			"Comment": "v1.0.1-3-g9d99fac",
+			"Rev": "9d99face20b0dd300b7db50b3f69758de41c096a"
+		},
+		{
+			"ImportPath": "github.com/xtaci/kcp-go",
+			"Comment": "v3.19-6-g21da33a",
+			"Rev": "21da33a6696d67c1bffb3c954366499d613097a6"
+		},
+		{
+			"ImportPath": "github.com/xtaci/smux",
+			"Comment": "v1.0.6",
+			"Rev": "ebec7ef2574b42a7088cd7751176483e0a27d458"
+		},
+		{
+			"ImportPath": "golang.org/x/crypto/blowfish",
+			"Rev": "f899cbd3df85058aa20d1cf129473b18f2a2b49f"
+		},
+		{
+			"ImportPath": "golang.org/x/crypto/cast5",
+			"Rev": "86e16787bfd59cb4db9e278c51a95488c141a5d6"
+		},
+		{
+			"ImportPath": "golang.org/x/crypto/curve25519",
+			"Rev": "1843fabd21d7180cf65e36759986d00c13dbb0fd"
+		},
+		{
+			"ImportPath": "golang.org/x/crypto/ed25519",
+			"Rev": "1843fabd21d7180cf65e36759986d00c13dbb0fd"
+		},
+		{
+			"ImportPath": "golang.org/x/crypto/ed25519/internal/edwards25519",
+			"Rev": "1843fabd21d7180cf65e36759986d00c13dbb0fd"
+		},
+		{
+			"ImportPath": "golang.org/x/crypto/pbkdf2",
+			"Rev": "1843fabd21d7180cf65e36759986d00c13dbb0fd"
+		},
+		{
+			"ImportPath": "golang.org/x/crypto/salsa20",
+			"Rev": "1843fabd21d7180cf65e36759986d00c13dbb0fd"
+		},
+		{
+			"ImportPath": "golang.org/x/crypto/salsa20/salsa",
+			"Rev": "1843fabd21d7180cf65e36759986d00c13dbb0fd"
+		},
+		{
+			"ImportPath": "golang.org/x/crypto/ssh",
+			"Rev": "1843fabd21d7180cf65e36759986d00c13dbb0fd"
+		},
+		{
+			"ImportPath": "golang.org/x/crypto/tea",
+			"Rev": "1843fabd21d7180cf65e36759986d00c13dbb0fd"
+		},
+		{
+			"ImportPath": "golang.org/x/crypto/twofish",
+			"Rev": "1843fabd21d7180cf65e36759986d00c13dbb0fd"
+		},
+		{
+			"ImportPath": "golang.org/x/crypto/xtea",
+			"Rev": "1843fabd21d7180cf65e36759986d00c13dbb0fd"
+		},
+		{
+			"ImportPath": "golang.org/x/net/bpf",
+			"Rev": "114479435b31b5077a087cc5303a45cb5d355dc4"
+		},
+		{
+			"ImportPath": "golang.org/x/net/internal/iana",
+			"Rev": "114479435b31b5077a087cc5303a45cb5d355dc4"
+		},
+		{
+			"ImportPath": "golang.org/x/net/internal/socket",
+			"Rev": "114479435b31b5077a087cc5303a45cb5d355dc4"
+		},
+		{
+			"ImportPath": "golang.org/x/net/ipv4",
+			"Rev": "114479435b31b5077a087cc5303a45cb5d355dc4"
+		},
+		{
+			"ImportPath": "golang.org/x/time/rate",
+			"Rev": "8be79e1e0910c292df4e79c241bb7e8f7e725959"
+		},
+		{
+			"ImportPath": "gopkg.in/alecthomas/kingpin.v2",
+			"Comment": "v2.2.5",
+			"Rev": "1087e65c9441605df944fb12c33f0fe7072d18ca"
+		}
+	]
+}

Godeps/Readme

@@ -0,0 +1,5 @@
+This directory tree is generated automatically by godep.
+
+Please do not edit.
+
+See https://github.com/tools/godep for more information.

README.md

@@ -78,11 +78,11 @@ Proxy是golang实现的高性能http,https,websocket,tcp,udp,socks5代理服务
     - [2.5 加密三级TCP代理](#25加密三级tcp代理)
     - [2.6 查看帮助](#26查看帮助)
 - [3. UDP代理](#3udp代理)
-    - [3.1 普通一级TCP代理](#31普通一级udp代理)
+    - [3.1 普通一级UDP代理](#31普通一级udp代理)
-    - [3.2 普通二级TCP代理](#32普通二级udp代理)
+    - [3.2 普通二级UDP代理](#32普通二级udp代理)
-    - [3.3 普通三级TCP代理](#33普通三级udp代理)
+    - [3.3 普通三级UDP代理](#33普通三级udp代理)
-    - [3.4 加密二级TCP代理](#34加密二级udp代理)
+    - [3.4 加密二级UDP代理](#34加密二级udp代理)
-    - [3.5 加密三级TCP代理](#35加密三级udp代理)
+    - [3.5 加密三级UDP代理](#35加密三级udp代理)
     - [3.6 查看帮助](#36查看帮助)
 - [4. 内网穿透](#4内网穿透)
     - [4.1 原理说明](#41原理说明)
@@ -134,7 +134,7 @@ chmod +x install.sh
   
 ## **首次使用必看**  
   
-#### **环境**  
+### **环境**  
 接下来的教程,默认系统是linux,程序是proxy；所有操作需要root权限；  
 如果你的是windows,请使用windows版本的proxy.exe即可.  
   
@@ -184,6 +184,7 @@ proxy会fork子进程,然后监控子进程,如果子进程异常退出,5秒后
 
 ### **1.HTTP代理**  
 #### **1.1.普通HTTP代理**  
+![1.1](/docs/images/1.1.jpg)  
 `./proxy http -t tcp -p "0.0.0.0:38080"`  
   
 #### **1.2.普通二级HTTP代理**  
@@ -192,7 +193,7 @@ proxy会fork子进程,然后监控子进程,如果子进程异常退出,5秒后
 默认关闭了连接池,如果要加快访问速度,-L可以开启连接池,10就是连接池大小,0为关闭,  
 开启连接池在网络不好的情况下,稳定不是很好.   
 `./proxy http -t tcp -p "0.0.0.0:8090" -T tcp -P "22.22.22.22:8080" -L 10`  
-我们还可以指定网站域名的黑白名单文件,一行一个域名,怕匹配规则是最右批评匹配,比如:baidu.com,匹配的是*.*.baidu.com,黑名单的域名域名直接走上级代理,白名单的域名不走上级代理.  
+我们还可以指定网站域名的黑白名单文件,一行一个域名,匹配规则是最右匹配,比如:baidu.com,匹配的是*.*.baidu.com,黑名单的域名域名直接走上级代理,白名单的域名不走上级代理.  
 `./proxy http -p "0.0.0.0:8090" -T tcp -P "22.22.22.22:8080"  -b blocked.txt -d direct.txt`  
   
 #### **1.3.HTTP二级代理(加密)**  
@@ -271,11 +272,13 @@ KCP协议需要-B参数设置一个密码用于加密解密数据
 ### **2.TCP代理**  
   
 #### **2.1.普通一级TCP代理**  
+![2.1](/docs/images/2.1.png)  
 本地执行:  
 `./proxy tcp -p ":33080" -T tcp -P "192.168.22.33:22" -L 0`  
 那么访问本地33080端口就是访问192.168.22.33的22端口.  
   
 #### **2.2.普通二级TCP代理**  
+![2.2](/docs/images/2.2.png)  
 VPS(IP:22.22.22.33)执行:  
 `./proxy tcp -p ":33080" -T tcp -P "127.0.0.1:8080" -L 0`  
 本地执行:  
@@ -293,16 +296,16 @@ VPS(IP:22.22.22.33)执行:
   
 #### **2.4.加密二级TCP代理**  
 VPS(IP:22.22.22.33)执行:  
-`./proxy tcp --tls -p ":33080" -T tcp -P "127.0.0.1:8080" -L 0 -C proxy.crt -K proxy.key`  
+`./proxy tcp -t tcp -p ":33080" -T tcp -P "127.0.0.1:8080" -L 0 -C proxy.crt -K proxy.key`  
 本地执行:  
 `./proxy tcp -p ":23080" -T tls -P "22.22.22.33:33080" -C proxy.crt -K proxy.key`  
 那么访问本地23080端口就是通过加密TCP隧道访问22.22.22.33的8080端口.  
   
 #### **2.5.加密三级TCP代理**  
 一级TCP代理VPS_01,IP:22.22.22.22  
-`./proxy tcp --tls -p ":38080" -T tcp -P "66.66.66.66:8080" -C proxy.crt -K proxy.key`  
+`./proxy tcp -t tcp -p ":38080" -T tcp -P "66.66.66.66:8080" -C proxy.crt -K proxy.key`  
 二级TCP代理VPS_02,IP:33.33.33.33  
-`./proxy tcp --tls -p ":28080" -T tls -P "22.22.22.22:38080" -C proxy.crt -K proxy.key`  
+`./proxy tcp -t tcp -p ":28080" -T tls -P "22.22.22.22:38080" -C proxy.crt -K proxy.key`  
 三级TCP代理(本地)  
 `./proxy tcp -p ":8080" -T tls -P "33.33.33.33:28080" -C proxy.crt -K proxy.key`  
 那么访问本地8080端口就是通过加密TCP隧道访问66.66.66.66的8080端口.  
@@ -335,16 +338,16 @@ VPS(IP:22.22.22.33)执行:
   
 #### **3.4.加密二级UDP代理**  
 VPS(IP:22.22.22.33)执行:  
-`./proxy tcp --tls -p ":33080" -T udp -P "8.8.8.8:53" -C proxy.crt -K proxy.key`  
+`./proxy tcp -t tcp -p ":33080" -T udp -P "8.8.8.8:53" -C proxy.crt -K proxy.key`  
 本地执行:  
 `./proxy udp -p ":5353" -T tls -P "22.22.22.33:33080" -C proxy.crt -K proxy.key`  
 那么访问本地UDP:5353端口就是通过加密TCP隧道,通过VPS访问8.8.8.8的UDP:53端口.  
   
 #### **3.5.加密三级UDP代理**  
 一级TCP代理VPS_01,IP:22.22.22.22  
-`./proxy tcp --tls -p ":38080" -T udp -P "8.8.8.8:53" -C proxy.crt -K proxy.key`  
+`./proxy tcp -t tcp -p ":38080" -T udp -P "8.8.8.8:53" -C proxy.crt -K proxy.key`  
 二级TCP代理VPS_02,IP:33.33.33.33  
-`./proxy tcp --tls -p ":28080" -T tls -P "22.22.22.22:38080" -C proxy.crt -K proxy.key`  
+`./proxy tcp -t tcp -p ":28080" -T tls -P "22.22.22.22:38080" -C proxy.crt -K proxy.key`  
 三级TCP代理(本地)  
 `./proxy udp -p ":5353" -T tls -P "33.33.33.33:28080" -C proxy.crt -K proxy.key`  
 那么访问本地5353端口就是通过加密TCP隧道,通过VPS_01访问8.8.8.8的53端口.  
@@ -500,9 +503,10 @@ server连接到bridge的时候,如果同时有多个client连接到同一个brid
 `./proxy socks -t tcp -p "0.0.0.0:38080"`  
   
 #### **5.2.普通二级SOCKS5代理**  
+![5.2](/docs/images/5.2.png)  
 使用本地端口8090,假设上级SOCKS5代理是`22.22.22.22:8080`  
 `./proxy socks -t tcp -p "0.0.0.0:8090" -T tcp -P "22.22.22.22:8080" `  
-我们还可以指定网站域名的黑白名单文件,一行一个域名,怕匹配规则是最右批评匹配,比如:baidu.com,匹配的是*.*.baidu.com,黑名单的域名域名直接走上级代理,白名单的域名不走上级代理.  
+我们还可以指定网站域名的黑白名单文件,一行一个域名,匹配规则是最右匹配,比如:baidu.com,匹配的是*.*.baidu.com,黑名单的域名域名直接走上级代理,白名单的域名不走上级代理.  
 `./proxy socks -p "0.0.0.0:8090" -T tcp -P "22.22.22.22:8080"  -b blocked.txt -d direct.txt`  
   
 #### **5.3.SOCKS二级代理(加密)**  
@@ -584,7 +588,8 @@ KCP协议需要-B参数设置一个密码用于加密解密数据
 - http(s)代理增加pac支持?
 - 欢迎加群反馈...
 
-### 如何使用源码?   
+### 如何使用源码? 
+建议go1.8,不保证>=1.9能用.   
 cd进入你的go src目录,然后git clone https://github.com/snail007/goproxy.git ./proxy 即可.   
 编译直接:go build     
 运行: go run *.go    

release.sh

@@ -16,8 +16,8 @@ CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=6 go build && tar zcfv "${RELEASE}/pro
 CGO_ENABLED=0 GOOS=linux GOARCH=arm64 GOARM=6 go build && tar zcfv "${RELEASE}/proxy-linux-arm64-v6.tar.gz" proxy direct blocked 
 CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=7 go build && tar zcfv "${RELEASE}/proxy-linux-arm-v7.tar.gz" proxy direct blocked 
 CGO_ENABLED=0 GOOS=linux GOARCH=arm64 GOARM=7 go build && tar zcfv "${RELEASE}/proxy-linux-arm64-v7.tar.gz" proxy direct blocked 
-CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=8 go build && tar zcfv "${RELEASE}/proxy-linux-arm-v8.tar.gz" proxy direct blocked 
+CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=5 go build && tar zcfv "${RELEASE}/proxy-linux-arm-v5.tar.gz" proxy direct blocked 
-CGO_ENABLED=0 GOOS=linux GOARCH=arm64 GOARM=8 go build && tar zcfv "${RELEASE}/proxy-linux-arm64-v8.tar.gz" proxy direct blocked 
+CGO_ENABLED=0 GOOS=linux GOARCH=arm64 GOARM=5 go build && tar zcfv "${RELEASE}/proxy-linux-arm64-v5.tar.gz" proxy direct blocked 
 CGO_ENABLED=0 GOOS=linux GOARCH=mips go build && tar zcfv "${RELEASE}/proxy-linux-mips.tar.gz" proxy direct blocked 
 CGO_ENABLED=0 GOOS=linux GOARCH=mips64 go build && tar zcfv "${RELEASE}/proxy-linux-mips64.tar.gz" proxy direct blocked 
 CGO_ENABLED=0 GOOS=linux GOARCH=mips64le go build && tar zcfv "${RELEASE}/proxy-linux-mips64le.tar.gz" proxy direct blocked 

services/http.go

@@ -161,11 +161,7 @@ func (s *HTTP) callback(inConn net.Conn) {
 		} else if *s.cfg.Always {
 			useProxy = true
 		} else {
-			if req.IsHTTPS() {
+			s.checker.Add(address)
-				s.checker.Add(address, true, req.Method, "", nil)
-			} else {
-				s.checker.Add(address, false, req.Method, req.URL, req.HeadBuf)
-			}
 			//var n, m uint
 			useProxy, _, _ = s.checker.IsBlocked(req.Host)
 			//log.Printf("blocked ? : %v, %s , fail:%d ,success:%d", useProxy, address, n, m)

services/socks.go

@@ -421,7 +421,7 @@ func (s *Socks) proxyTCP(inConn *net.Conn, methodReq socks.MethodsRequest, reque
 				if utils.IsIternalIP(host) {
 					useProxy = false
 				} else {
-					s.checker.Add(request.Addr(), true, "", "", nil)
+					s.checker.Add(request.Addr())
 					useProxy, _, _ = s.checker.IsBlocked(request.Addr())
 				}
 				if useProxy {

utils/sni/sni.go

@@ -0,0 +1,173 @@
+package sni
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"io"
+	"net"
+)
+
+func ServerNameFromBytes(data []byte) (sn string, err error) {
+	reader := bytes.NewReader(data)
+	bufferedReader := bufio.NewReader(reader)
+	c := bufferedConn{bufferedReader, nil, nil}
+	sn, _, err = ServerNameFromConn(c)
+	return
+}
+
+type bufferedConn struct {
+	r    *bufio.Reader
+	rout io.Reader
+	net.Conn
+}
+
+func newBufferedConn(c net.Conn) bufferedConn {
+	return bufferedConn{bufio.NewReader(c), nil, c}
+}
+
+func (b bufferedConn) Peek(n int) ([]byte, error) {
+	return b.r.Peek(n)
+}
+
+func (b bufferedConn) Read(p []byte) (int, error) {
+	if b.rout != nil {
+		return b.rout.Read(p)
+	}
+	return b.r.Read(p)
+}
+
+var malformedError = errors.New("malformed client hello")
+
+func getHello(b []byte) (string, error) {
+	rest := b[5:]
+
+	if len(rest) == 0 {
+		return "", malformedError
+	}
+
+	current := 0
+	handshakeType := rest[0]
+	current += 1
+	if handshakeType != 0x1 {
+		return "", errors.New("Not a ClientHello")
+	}
+
+	// Skip over another length
+	current += 3
+	// Skip over protocolversion
+	current += 2
+	// Skip over random number
+	current += 4 + 28
+
+	if current > len(rest) {
+		return "", malformedError
+	}
+
+	// Skip over session ID
+	sessionIDLength := int(rest[current])
+	current += 1
+	current += sessionIDLength
+
+	if current+1 > len(rest) {
+		return "", malformedError
+	}
+
+	cipherSuiteLength := (int(rest[current]) << 8) + int(rest[current+1])
+	current += 2
+	current += cipherSuiteLength
+
+	if current > len(rest) {
+		return "", malformedError
+	}
+	compressionMethodLength := int(rest[current])
+	current += 1
+	current += compressionMethodLength
+
+	if current > len(rest) {
+		return "", errors.New("no extensions")
+	}
+
+	current += 2
+
+	hostname := ""
+	for current+4 < len(rest) && hostname == "" {
+		extensionType := (int(rest[current]) << 8) + int(rest[current+1])
+		current += 2
+
+		extensionDataLength := (int(rest[current]) << 8) + int(rest[current+1])
+		current += 2
+
+		if extensionType == 0 {
+
+			// Skip over number of names as we're assuming there's just one
+			current += 2
+			if current > len(rest) {
+				return "", malformedError
+			}
+
+			nameType := rest[current]
+			current += 1
+			if nameType != 0 {
+				return "", errors.New("Not a hostname")
+			}
+			if current+1 > len(rest) {
+				return "", malformedError
+			}
+			nameLen := (int(rest[current]) << 8) + int(rest[current+1])
+			current += 2
+			if current+nameLen > len(rest) {
+				return "", malformedError
+			}
+			hostname = string(rest[current : current+nameLen])
+		}
+
+		current += extensionDataLength
+	}
+	if hostname == "" {
+		return "", errors.New("No hostname")
+	}
+	return hostname, nil
+
+}
+
+func getHelloBytes(c bufferedConn) ([]byte, error) {
+	b, err := c.Peek(5)
+	if err != nil {
+		return []byte{}, err
+	}
+
+	if b[0] != 0x16 {
+		return []byte{}, errors.New("not TLS")
+	}
+
+	restLengthBytes := b[3:]
+	restLength := (int(restLengthBytes[0]) << 8) + int(restLengthBytes[1])
+
+	return c.Peek(5 + restLength)
+
+}
+
+func getServername(c bufferedConn) (string, []byte, error) {
+	all, err := getHelloBytes(c)
+	if err != nil {
+		return "", nil, err
+	}
+	name, err := getHello(all)
+	if err != nil {
+		return "", nil, err
+	}
+	return name, all, err
+
+}
+
+// Uses SNI to get the name of the server from the connection. Returns the ServerName and a buffered connection that will not have been read off of.
+func ServerNameFromConn(c net.Conn) (string, net.Conn, error) {
+	bufconn := newBufferedConn(c)
+	sn, helloBytes, err := getServername(bufconn)
+	if err != nil {
+		return "", nil, err
+	}
+	bufconn.rout = io.MultiReader(bytes.NewBuffer(helloBytes), c)
+	return sn, bufconn, nil
+}

utils/structs.go

@@ -74,21 +74,19 @@ func (c *Checker) loadMap(f string) (dataMap ConcurrentMap) {
 }
 func (c *Checker) start() {
 	go func() {
+		//log.Printf("checker started")
 		for {
+			//log.Printf("checker did")
 			for _, v := range c.data.Items() {
 				go func(item CheckerItem) {
 					if c.isNeedCheck(item) {
-						//log.Printf("check %s", item.Domain)
+						//log.Printf("check %s", item.Host)
 						var conn net.Conn
 						var err error
-						if item.IsHTTPS {
+						conn, err = ConnectHost(item.Host, c.timeout)
-							conn, err = ConnectHost(item.Host, c.timeout)
+						if err == nil {
-							if err == nil {
+							conn.SetDeadline(time.Now().Add(time.Millisecond))
-								conn.SetDeadline(time.Now().Add(time.Millisecond))
+							conn.Close()
-								conn.Close()
-							}
-						} else {
-							err = HTTPGet(item.URL, c.timeout)
 						}
 						if err != nil {
 							item.FailCount = item.FailCount + 1
@@ -155,22 +153,13 @@ func (c *Checker) domainIsInMap(address string, blockedMap bool) bool {
 	}
 	return false
 }
-func (c *Checker) Add(address string, isHTTPS bool, method, URL string, data []byte) {
+func (c *Checker) Add(address string) {
 	if c.domainIsInMap(address, false) || c.domainIsInMap(address, true) {
 		return
 	}
-	if !isHTTPS && strings.ToLower(method) != "get" {
-		return
-	}
 	var item CheckerItem
-	u := strings.Split(address, ":")
 	item = CheckerItem{
-		URL:     URL,
+		Host: address,
-		Domain:  u[0],
-		Host:    address,
-		Data:    data,
-		IsHTTPS: isHTTPS,
-		Method:  method,
 	}
 	c.data.SetIfAbsent(item.Host, item)
 }
@@ -361,6 +350,12 @@ func (req *HTTPRequest) HTTP() (err error) {
 	return
 }
 func (req *HTTPRequest) HTTPS() (err error) {
+	if req.isBasicAuth {
+		err = req.BasicAuth()
+		if err != nil {
+			return
+		}
+	}
 	req.Host = req.hostOrURL
 	req.addPortIfNot()
 	//_, err = fmt.Fprint(*req.conn, "HTTP/1.1 200 Connection established\r\n\r\n")
@@ -376,7 +371,8 @@ func (req *HTTPRequest) IsHTTPS() bool {
 
 func (req *HTTPRequest) BasicAuth() (err error) {
 
-	//log.Printf("request :%s", string(b[:n]))
+	//log.Printf("request :%s", string(b[:n]))authorization
+	isProxyAuthorization := false
 	authorization, err := req.getHeader("Authorization")
 	if err != nil {
 		fmt.Fprint((*req.conn), "HTTP/1.1 401 Unauthorized\r\nWWW-Authenticate: Basic realm=\"\"\r\n\r\nUnauthorized")
@@ -386,10 +382,11 @@ func (req *HTTPRequest) BasicAuth() (err error) {
 	if authorization == "" {
 		authorization, err = req.getHeader("Proxy-Authorization")
 		if err != nil {
-			fmt.Fprint((*req.conn), "HTTP/1.1 401 Unauthorized\r\nWWW-Authenticate: Basic realm=\"\"\r\n\r\nUnauthorized")
+			fmt.Fprint((*req.conn), "HTTP/1.1 407 Unauthorized\r\nWWW-Authenticate: Basic realm=\"\"\r\n\r\nUnauthorized")
 			CloseConn(req.conn)
 			return
 		}
+		isProxyAuthorization = true
 	}
 	//log.Printf("Authorization:%s", authorization)
 	basic := strings.Fields(authorization)
@@ -414,7 +411,11 @@ func (req *HTTPRequest) BasicAuth() (err error) {
 	authOk := (*req.basicAuth).Check(string(user), addr[0], URL)
 	//log.Printf("auth %s,%v", string(user), authOk)
 	if !authOk {
-		fmt.Fprint((*req.conn), "HTTP/1.1 401 Unauthorized\r\n\r\nUnauthorized")
+		code := "401"
+		if isProxyAuthorization {
+			code = "407"
+		}
+		fmt.Fprintf((*req.conn), "HTTP/1.1 %s Unauthorized\r\n\r\nUnauthorized", code)
 		CloseConn(req.conn)
 		err = fmt.Errorf("basic auth fail")
 		return

vendor/github.com/alecthomas/template/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2012 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/alecthomas/template/README.md

@@ -0,0 +1,25 @@
+# Go's `text/template` package with newline elision
+
+This is a fork of Go 1.4's [text/template](http://golang.org/pkg/text/template/) package with one addition: a backslash immediately after a closing delimiter will delete all subsequent newlines until a non-newline.
+
+eg.
+
+```
+{{if true}}\
+hello
+{{end}}\
+```
+
+Will result in:
+
+```
+hello\n
+```
+
+Rather than:
+
+```
+\n
+hello\n
+\n
+```

vendor/github.com/alecthomas/template/doc.go

@@ -0,0 +1,406 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+Package template implements data-driven templates for generating textual output.
+
+To generate HTML output, see package html/template, which has the same interface
+as this package but automatically secures HTML output against certain attacks.
+
+Templates are executed by applying them to a data structure. Annotations in the
+template refer to elements of the data structure (typically a field of a struct
+or a key in a map) to control execution and derive values to be displayed.
+Execution of the template walks the structure and sets the cursor, represented
+by a period '.' and called "dot", to the value at the current location in the
+structure as execution proceeds.
+
+The input text for a template is UTF-8-encoded text in any format.
+"Actions"--data evaluations or control structures--are delimited by
+"{{" and "}}"; all text outside actions is copied to the output unchanged.
+Actions may not span newlines, although comments can.
+
+Once parsed, a template may be executed safely in parallel.
+
+Here is a trivial example that prints "17 items are made of wool".
+
+	type Inventory struct {
+		Material string
+		Count    uint
+	}
+	sweaters := Inventory{"wool", 17}
+	tmpl, err := template.New("test").Parse("{{.Count}} items are made of {{.Material}}")
+	if err != nil { panic(err) }
+	err = tmpl.Execute(os.Stdout, sweaters)
+	if err != nil { panic(err) }
+
+More intricate examples appear below.
+
+Actions
+
+Here is the list of actions. "Arguments" and "pipelines" are evaluations of
+data, defined in detail below.
+
+*/
+//	{{/* a comment */}}
+//		A comment; discarded. May contain newlines.
+//		Comments do not nest and must start and end at the
+//		delimiters, as shown here.
+/*
+
+	{{pipeline}}
+		The default textual representation of the value of the pipeline
+		is copied to the output.
+
+	{{if pipeline}} T1 {{end}}
+		If the value of the pipeline is empty, no output is generated;
+		otherwise, T1 is executed.  The empty values are false, 0, any
+		nil pointer or interface value, and any array, slice, map, or
+		string of length zero.
+		Dot is unaffected.
+
+	{{if pipeline}} T1 {{else}} T0 {{end}}
+		If the value of the pipeline is empty, T0 is executed;
+		otherwise, T1 is executed.  Dot is unaffected.
+
+	{{if pipeline}} T1 {{else if pipeline}} T0 {{end}}
+		To simplify the appearance of if-else chains, the else action
+		of an if may include another if directly; the effect is exactly
+		the same as writing
+			{{if pipeline}} T1 {{else}}{{if pipeline}} T0 {{end}}{{end}}
+
+	{{range pipeline}} T1 {{end}}
+		The value of the pipeline must be an array, slice, map, or channel.
+		If the value of the pipeline has length zero, nothing is output;
+		otherwise, dot is set to the successive elements of the array,
+		slice, or map and T1 is executed. If the value is a map and the
+		keys are of basic type with a defined order ("comparable"), the
+		elements will be visited in sorted key order.
+
+	{{range pipeline}} T1 {{else}} T0 {{end}}
+		The value of the pipeline must be an array, slice, map, or channel.
+		If the value of the pipeline has length zero, dot is unaffected and
+		T0 is executed; otherwise, dot is set to the successive elements
+		of the array, slice, or map and T1 is executed.
+
+	{{template "name"}}
+		The template with the specified name is executed with nil data.
+
+	{{template "name" pipeline}}
+		The template with the specified name is executed with dot set
+		to the value of the pipeline.
+
+	{{with pipeline}} T1 {{end}}
+		If the value of the pipeline is empty, no output is generated;
+		otherwise, dot is set to the value of the pipeline and T1 is
+		executed.
+
+	{{with pipeline}} T1 {{else}} T0 {{end}}
+		If the value of the pipeline is empty, dot is unaffected and T0
+		is executed; otherwise, dot is set to the value of the pipeline
+		and T1 is executed.
+
+Arguments
+
+An argument is a simple value, denoted by one of the following.
+
+	- A boolean, string, character, integer, floating-point, imaginary
+	  or complex constant in Go syntax. These behave like Go's untyped
+	  constants, although raw strings may not span newlines.
+	- The keyword nil, representing an untyped Go nil.
+	- The character '.' (period):
+		.
+	  The result is the value of dot.
+	- A variable name, which is a (possibly empty) alphanumeric string
+	  preceded by a dollar sign, such as
+		$piOver2
+	  or
+		$
+	  The result is the value of the variable.
+	  Variables are described below.
+	- The name of a field of the data, which must be a struct, preceded
+	  by a period, such as
+		.Field
+	  The result is the value of the field. Field invocations may be
+	  chained:
+	    .Field1.Field2
+	  Fields can also be evaluated on variables, including chaining:
+	    $x.Field1.Field2
+	- The name of a key of the data, which must be a map, preceded
+	  by a period, such as
+		.Key
+	  The result is the map element value indexed by the key.
+	  Key invocations may be chained and combined with fields to any
+	  depth:
+	    .Field1.Key1.Field2.Key2
+	  Although the key must be an alphanumeric identifier, unlike with
+	  field names they do not need to start with an upper case letter.
+	  Keys can also be evaluated on variables, including chaining:
+	    $x.key1.key2
+	- The name of a niladic method of the data, preceded by a period,
+	  such as
+		.Method
+	  The result is the value of invoking the method with dot as the
+	  receiver, dot.Method(). Such a method must have one return value (of
+	  any type) or two return values, the second of which is an error.
+	  If it has two and the returned error is non-nil, execution terminates
+	  and an error is returned to the caller as the value of Execute.
+	  Method invocations may be chained and combined with fields and keys
+	  to any depth:
+	    .Field1.Key1.Method1.Field2.Key2.Method2
+	  Methods can also be evaluated on variables, including chaining:
+	    $x.Method1.Field
+	- The name of a niladic function, such as
+		fun
+	  The result is the value of invoking the function, fun(). The return
+	  types and values behave as in methods. Functions and function
+	  names are described below.
+	- A parenthesized instance of one the above, for grouping. The result
+	  may be accessed by a field or map key invocation.
+		print (.F1 arg1) (.F2 arg2)
+		(.StructValuedMethod "arg").Field
+
+Arguments may evaluate to any type; if they are pointers the implementation
+automatically indirects to the base type when required.
+If an evaluation yields a function value, such as a function-valued
+field of a struct, the function is not invoked automatically, but it
+can be used as a truth value for an if action and the like. To invoke
+it, use the call function, defined below.
+
+A pipeline is a possibly chained sequence of "commands". A command is a simple
+value (argument) or a function or method call, possibly with multiple arguments:
+
+	Argument
+		The result is the value of evaluating the argument.
+	.Method [Argument...]
+		The method can be alone or the last element of a chain but,
+		unlike methods in the middle of a chain, it can take arguments.
+		The result is the value of calling the method with the
+		arguments:
+			dot.Method(Argument1, etc.)
+	functionName [Argument...]
+		The result is the value of calling the function associated
+		with the name:
+			function(Argument1, etc.)
+		Functions and function names are described below.
+
+Pipelines
+
+A pipeline may be "chained" by separating a sequence of commands with pipeline
+characters '|'. In a chained pipeline, the result of the each command is
+passed as the last argument of the following command. The output of the final
+command in the pipeline is the value of the pipeline.
+
+The output of a command will be either one value or two values, the second of
+which has type error. If that second value is present and evaluates to
+non-nil, execution terminates and the error is returned to the caller of
+Execute.
+
+Variables
+
+A pipeline inside an action may initialize a variable to capture the result.
+The initialization has syntax
+
+	$variable := pipeline
+
+where $variable is the name of the variable. An action that declares a
+variable produces no output.
+
+If a "range" action initializes a variable, the variable is set to the
+successive elements of the iteration.  Also, a "range" may declare two
+variables, separated by a comma:
+
+	range $index, $element := pipeline
+
+in which case $index and $element are set to the successive values of the
+array/slice index or map key and element, respectively.  Note that if there is
+only one variable, it is assigned the element; this is opposite to the
+convention in Go range clauses.
+
+A variable's scope extends to the "end" action of the control structure ("if",
+"with", or "range") in which it is declared, or to the end of the template if
+there is no such control structure.  A template invocation does not inherit
+variables from the point of its invocation.
+
+When execution begins, $ is set to the data argument passed to Execute, that is,
+to the starting value of dot.
+
+Examples
+
+Here are some example one-line templates demonstrating pipelines and variables.
+All produce the quoted word "output":
+
+	{{"\"output\""}}
+		A string constant.
+	{{`"output"`}}
+		A raw string constant.
+	{{printf "%q" "output"}}
+		A function call.
+	{{"output" | printf "%q"}}
+		A function call whose final argument comes from the previous
+		command.
+	{{printf "%q" (print "out" "put")}}
+		A parenthesized argument.
+	{{"put" | printf "%s%s" "out" | printf "%q"}}
+		A more elaborate call.
+	{{"output" | printf "%s" | printf "%q"}}
+		A longer chain.
+	{{with "output"}}{{printf "%q" .}}{{end}}
+		A with action using dot.
+	{{with $x := "output" | printf "%q"}}{{$x}}{{end}}
+		A with action that creates and uses a variable.
+	{{with $x := "output"}}{{printf "%q" $x}}{{end}}
+		A with action that uses the variable in another action.
+	{{with $x := "output"}}{{$x | printf "%q"}}{{end}}
+		The same, but pipelined.
+
+Functions
+
+During execution functions are found in two function maps: first in the
+template, then in the global function map. By default, no functions are defined
+in the template but the Funcs method can be used to add them.
+
+Predefined global functions are named as follows.
+
+	and
+		Returns the boolean AND of its arguments by returning the
+		first empty argument or the last argument, that is,
+		"and x y" behaves as "if x then y else x". All the
+		arguments are evaluated.
+	call
+		Returns the result of calling the first argument, which
+		must be a function, with the remaining arguments as parameters.
+		Thus "call .X.Y 1 2" is, in Go notation, dot.X.Y(1, 2) where
+		Y is a func-valued field, map entry, or the like.
+		The first argument must be the result of an evaluation
+		that yields a value of function type (as distinct from
+		a predefined function such as print). The function must
+		return either one or two result values, the second of which
+		is of type error. If the arguments don't match the function
+		or the returned error value is non-nil, execution stops.
+	html
+		Returns the escaped HTML equivalent of the textual
+		representation of its arguments.
+	index
+		Returns the result of indexing its first argument by the
+		following arguments. Thus "index x 1 2 3" is, in Go syntax,
+		x[1][2][3]. Each indexed item must be a map, slice, or array.
+	js
+		Returns the escaped JavaScript equivalent of the textual
+		representation of its arguments.
+	len
+		Returns the integer length of its argument.
+	not
+		Returns the boolean negation of its single argument.
+	or
+		Returns the boolean OR of its arguments by returning the
+		first non-empty argument or the last argument, that is,
+		"or x y" behaves as "if x then x else y". All the
+		arguments are evaluated.
+	print
+		An alias for fmt.Sprint
+	printf
+		An alias for fmt.Sprintf
+	println
+		An alias for fmt.Sprintln
+	urlquery
+		Returns the escaped value of the textual representation of
+		its arguments in a form suitable for embedding in a URL query.
+
+The boolean functions take any zero value to be false and a non-zero
+value to be true.
+
+There is also a set of binary comparison operators defined as
+functions:
+
+	eq
+		Returns the boolean truth of arg1 == arg2
+	ne
+		Returns the boolean truth of arg1 != arg2
+	lt
+		Returns the boolean truth of arg1 < arg2
+	le
+		Returns the boolean truth of arg1 <= arg2
+	gt
+		Returns the boolean truth of arg1 > arg2
+	ge
+		Returns the boolean truth of arg1 >= arg2
+
+For simpler multi-way equality tests, eq (only) accepts two or more
+arguments and compares the second and subsequent to the first,
+returning in effect
+
+	arg1==arg2 || arg1==arg3 || arg1==arg4 ...
+
+(Unlike with || in Go, however, eq is a function call and all the
+arguments will be evaluated.)
+
+The comparison functions work on basic types only (or named basic
+types, such as "type Celsius float32"). They implement the Go rules
+for comparison of values, except that size and exact type are
+ignored, so any integer value, signed or unsigned, may be compared
+with any other integer value. (The arithmetic value is compared,
+not the bit pattern, so all negative integers are less than all
+unsigned integers.) However, as usual, one may not compare an int
+with a float32 and so on.
+
+Associated templates
+
+Each template is named by a string specified when it is created. Also, each
+template is associated with zero or more other templates that it may invoke by
+name; such associations are transitive and form a name space of templates.
+
+A template may use a template invocation to instantiate another associated
+template; see the explanation of the "template" action above. The name must be
+that of a template associated with the template that contains the invocation.
+
+Nested template definitions
+
+When parsing a template, another template may be defined and associated with the
+template being parsed. Template definitions must appear at the top level of the
+template, much like global variables in a Go program.
+
+The syntax of such definitions is to surround each template declaration with a
+"define" and "end" action.
+
+The define action names the template being created by providing a string
+constant. Here is a simple example:
+
+	`{{define "T1"}}ONE{{end}}
+	{{define "T2"}}TWO{{end}}
+	{{define "T3"}}{{template "T1"}} {{template "T2"}}{{end}}
+	{{template "T3"}}`
+
+This defines two templates, T1 and T2, and a third T3 that invokes the other two
+when it is executed. Finally it invokes T3. If executed this template will
+produce the text
+
+	ONE TWO
+
+By construction, a template may reside in only one association. If it's
+necessary to have a template addressable from multiple associations, the
+template definition must be parsed multiple times to create distinct *Template
+values, or must be copied with the Clone or AddParseTree method.
+
+Parse may be called multiple times to assemble the various associated templates;
+see the ParseFiles and ParseGlob functions and methods for simple ways to parse
+related templates stored in files.
+
+A template may be executed directly or through ExecuteTemplate, which executes
+an associated template identified by name. To invoke our example above, we
+might write,
+
+	err := tmpl.Execute(os.Stdout, "no data needed")
+	if err != nil {
+		log.Fatalf("execution failed: %s", err)
+	}
+
+or to invoke a particular template explicitly by name,
+
+	err := tmpl.ExecuteTemplate(os.Stdout, "T2", "no data needed")
+	if err != nil {
+		log.Fatalf("execution failed: %s", err)
+	}
+
+*/
+package template

vendor/github.com/alecthomas/template/exec.go

@@ -0,0 +1,845 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package template
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"reflect"
+	"runtime"
+	"sort"
+	"strings"
+
+	"github.com/alecthomas/template/parse"
+)
+
+// state represents the state of an execution. It's not part of the
+// template so that multiple executions of the same template
+// can execute in parallel.
+type state struct {
+	tmpl *Template
+	wr   io.Writer
+	node parse.Node // current node, for errors
+	vars []variable // push-down stack of variable values.
+}
+
+// variable holds the dynamic value of a variable such as $, $x etc.
+type variable struct {
+	name  string
+	value reflect.Value
+}
+
+// push pushes a new variable on the stack.
+func (s *state) push(name string, value reflect.Value) {
+	s.vars = append(s.vars, variable{name, value})
+}
+
+// mark returns the length of the variable stack.
+func (s *state) mark() int {
+	return len(s.vars)
+}
+
+// pop pops the variable stack up to the mark.
+func (s *state) pop(mark int) {
+	s.vars = s.vars[0:mark]
+}
+
+// setVar overwrites the top-nth variable on the stack. Used by range iterations.
+func (s *state) setVar(n int, value reflect.Value) {
+	s.vars[len(s.vars)-n].value = value
+}
+
+// varValue returns the value of the named variable.
+func (s *state) varValue(name string) reflect.Value {
+	for i := s.mark() - 1; i >= 0; i-- {
+		if s.vars[i].name == name {
+			return s.vars[i].value
+		}
+	}
+	s.errorf("undefined variable: %s", name)
+	return zero
+}
+
+var zero reflect.Value
+
+// at marks the state to be on node n, for error reporting.
+func (s *state) at(node parse.Node) {
+	s.node = node
+}
+
+// doublePercent returns the string with %'s replaced by %%, if necessary,
+// so it can be used safely inside a Printf format string.
+func doublePercent(str string) string {
+	if strings.Contains(str, "%") {
+		str = strings.Replace(str, "%", "%%", -1)
+	}
+	return str
+}
+
+// errorf formats the error and terminates processing.
+func (s *state) errorf(format string, args ...interface{}) {
+	name := doublePercent(s.tmpl.Name())
+	if s.node == nil {
+		format = fmt.Sprintf("template: %s: %s", name, format)
+	} else {
+		location, context := s.tmpl.ErrorContext(s.node)
+		format = fmt.Sprintf("template: %s: executing %q at <%s>: %s", location, name, doublePercent(context), format)
+	}
+	panic(fmt.Errorf(format, args...))
+}
+
+// errRecover is the handler that turns panics into returns from the top
+// level of Parse.
+func errRecover(errp *error) {
+	e := recover()
+	if e != nil {
+		switch err := e.(type) {
+		case runtime.Error:
+			panic(e)
+		case error:
+			*errp = err
+		default:
+			panic(e)
+		}
+	}
+}
+
+// ExecuteTemplate applies the template associated with t that has the given name
+// to the specified data object and writes the output to wr.
+// If an error occurs executing the template or writing its output,
+// execution stops, but partial results may already have been written to
+// the output writer.
+// A template may be executed safely in parallel.
+func (t *Template) ExecuteTemplate(wr io.Writer, name string, data interface{}) error {
+	tmpl := t.tmpl[name]
+	if tmpl == nil {
+		return fmt.Errorf("template: no template %q associated with template %q", name, t.name)
+	}
+	return tmpl.Execute(wr, data)
+}
+
+// Execute applies a parsed template to the specified data object,
+// and writes the output to wr.
+// If an error occurs executing the template or writing its output,
+// execution stops, but partial results may already have been written to
+// the output writer.
+// A template may be executed safely in parallel.
+func (t *Template) Execute(wr io.Writer, data interface{}) (err error) {
+	defer errRecover(&err)
+	value := reflect.ValueOf(data)
+	state := &state{
+		tmpl: t,
+		wr:   wr,
+		vars: []variable{{"$", value}},
+	}
+	t.init()
+	if t.Tree == nil || t.Root == nil {
+		var b bytes.Buffer
+		for name, tmpl := range t.tmpl {
+			if tmpl.Tree == nil || tmpl.Root == nil {
+				continue
+			}
+			if b.Len() > 0 {
+				b.WriteString(", ")
+			}
+			fmt.Fprintf(&b, "%q", name)
+		}
+		var s string
+		if b.Len() > 0 {
+			s = "; defined templates are: " + b.String()
+		}
+		state.errorf("%q is an incomplete or empty template%s", t.Name(), s)
+	}
+	state.walk(value, t.Root)
+	return
+}
+
+// Walk functions step through the major pieces of the template structure,
+// generating output as they go.
+func (s *state) walk(dot reflect.Value, node parse.Node) {
+	s.at(node)
+	switch node := node.(type) {
+	case *parse.ActionNode:
+		// Do not pop variables so they persist until next end.
+		// Also, if the action declares variables, don't print the result.
+		val := s.evalPipeline(dot, node.Pipe)
+		if len(node.Pipe.Decl) == 0 {
+			s.printValue(node, val)
+		}
+	case *parse.IfNode:
+		s.walkIfOrWith(parse.NodeIf, dot, node.Pipe, node.List, node.ElseList)
+	case *parse.ListNode:
+		for _, node := range node.Nodes {
+			s.walk(dot, node)
+		}
+	case *parse.RangeNode:
+		s.walkRange(dot, node)
+	case *parse.TemplateNode:
+		s.walkTemplate(dot, node)
+	case *parse.TextNode:
+		if _, err := s.wr.Write(node.Text); err != nil {
+			s.errorf("%s", err)
+		}
+	case *parse.WithNode:
+		s.walkIfOrWith(parse.NodeWith, dot, node.Pipe, node.List, node.ElseList)
+	default:
+		s.errorf("unknown node: %s", node)
+	}
+}
+
+// walkIfOrWith walks an 'if' or 'with' node. The two control structures
+// are identical in behavior except that 'with' sets dot.
+func (s *state) walkIfOrWith(typ parse.NodeType, dot reflect.Value, pipe *parse.PipeNode, list, elseList *parse.ListNode) {
+	defer s.pop(s.mark())
+	val := s.evalPipeline(dot, pipe)
+	truth, ok := isTrue(val)
+	if !ok {
+		s.errorf("if/with can't use %v", val)
+	}
+	if truth {
+		if typ == parse.NodeWith {
+			s.walk(val, list)
+		} else {
+			s.walk(dot, list)
+		}
+	} else if elseList != nil {
+		s.walk(dot, elseList)
+	}
+}
+
+// isTrue reports whether the value is 'true', in the sense of not the zero of its type,
+// and whether the value has a meaningful truth value.
+func isTrue(val reflect.Value) (truth, ok bool) {
+	if !val.IsValid() {
+		// Something like var x interface{}, never set. It's a form of nil.
+		return false, true
+	}
+	switch val.Kind() {
+	case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
+		truth = val.Len() > 0
+	case reflect.Bool:
+		truth = val.Bool()
+	case reflect.Complex64, reflect.Complex128:
+		truth = val.Complex() != 0
+	case reflect.Chan, reflect.Func, reflect.Ptr, reflect.Interface:
+		truth = !val.IsNil()
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		truth = val.Int() != 0
+	case reflect.Float32, reflect.Float64:
+		truth = val.Float() != 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		truth = val.Uint() != 0
+	case reflect.Struct:
+		truth = true // Struct values are always true.
+	default:
+		return
+	}
+	return truth, true
+}
+
+func (s *state) walkRange(dot reflect.Value, r *parse.RangeNode) {
+	s.at(r)
+	defer s.pop(s.mark())
+	val, _ := indirect(s.evalPipeline(dot, r.Pipe))
+	// mark top of stack before any variables in the body are pushed.
+	mark := s.mark()
+	oneIteration := func(index, elem reflect.Value) {
+		// Set top var (lexically the second if there are two) to the element.
+		if len(r.Pipe.Decl) > 0 {
+			s.setVar(1, elem)
+		}
+		// Set next var (lexically the first if there are two) to the index.
+		if len(r.Pipe.Decl) > 1 {
+			s.setVar(2, index)
+		}
+		s.walk(elem, r.List)
+		s.pop(mark)
+	}
+	switch val.Kind() {
+	case reflect.Array, reflect.Slice:
+		if val.Len() == 0 {
+			break
+		}
+		for i := 0; i < val.Len(); i++ {
+			oneIteration(reflect.ValueOf(i), val.Index(i))
+		}
+		return
+	case reflect.Map:
+		if val.Len() == 0 {
+			break
+		}
+		for _, key := range sortKeys(val.MapKeys()) {
+			oneIteration(key, val.MapIndex(key))
+		}
+		return
+	case reflect.Chan:
+		if val.IsNil() {
+			break
+		}
+		i := 0
+		for ; ; i++ {
+			elem, ok := val.Recv()
+			if !ok {
+				break
+			}
+			oneIteration(reflect.ValueOf(i), elem)
+		}
+		if i == 0 {
+			break
+		}
+		return
+	case reflect.Invalid:
+		break // An invalid value is likely a nil map, etc. and acts like an empty map.
+	default:
+		s.errorf("range can't iterate over %v", val)
+	}
+	if r.ElseList != nil {
+		s.walk(dot, r.ElseList)
+	}
+}
+
+func (s *state) walkTemplate(dot reflect.Value, t *parse.TemplateNode) {
+	s.at(t)
+	tmpl := s.tmpl.tmpl[t.Name]
+	if tmpl == nil {
+		s.errorf("template %q not defined", t.Name)
+	}
+	// Variables declared by the pipeline persist.
+	dot = s.evalPipeline(dot, t.Pipe)
+	newState := *s
+	newState.tmpl = tmpl
+	// No dynamic scoping: template invocations inherit no variables.
+	newState.vars = []variable{{"$", dot}}
+	newState.walk(dot, tmpl.Root)
+}
+
+// Eval functions evaluate pipelines, commands, and their elements and extract
+// values from the data structure by examining fields, calling methods, and so on.
+// The printing of those values happens only through walk functions.
+
+// evalPipeline returns the value acquired by evaluating a pipeline. If the
+// pipeline has a variable declaration, the variable will be pushed on the
+// stack. Callers should therefore pop the stack after they are finished
+// executing commands depending on the pipeline value.
+func (s *state) evalPipeline(dot reflect.Value, pipe *parse.PipeNode) (value reflect.Value) {
+	if pipe == nil {
+		return
+	}
+	s.at(pipe)
+	for _, cmd := range pipe.Cmds {
+		value = s.evalCommand(dot, cmd, value) // previous value is this one's final arg.
+		// If the object has type interface{}, dig down one level to the thing inside.
+		if value.Kind() == reflect.Interface && value.Type().NumMethod() == 0 {
+			value = reflect.ValueOf(value.Interface()) // lovely!
+		}
+	}
+	for _, variable := range pipe.Decl {
+		s.push(variable.Ident[0], value)
+	}
+	return value
+}
+
+func (s *state) notAFunction(args []parse.Node, final reflect.Value) {
+	if len(args) > 1 || final.IsValid() {
+		s.errorf("can't give argument to non-function %s", args[0])
+	}
+}
+
+func (s *state) evalCommand(dot reflect.Value, cmd *parse.CommandNode, final reflect.Value) reflect.Value {
+	firstWord := cmd.Args[0]
+	switch n := firstWord.(type) {
+	case *parse.FieldNode:
+		return s.evalFieldNode(dot, n, cmd.Args, final)
+	case *parse.ChainNode:
+		return s.evalChainNode(dot, n, cmd.Args, final)
+	case *parse.IdentifierNode:
+		// Must be a function.
+		return s.evalFunction(dot, n, cmd, cmd.Args, final)
+	case *parse.PipeNode:
+		// Parenthesized pipeline. The arguments are all inside the pipeline; final is ignored.
+		return s.evalPipeline(dot, n)
+	case *parse.VariableNode:
+		return s.evalVariableNode(dot, n, cmd.Args, final)
+	}
+	s.at(firstWord)
+	s.notAFunction(cmd.Args, final)
+	switch word := firstWord.(type) {
+	case *parse.BoolNode:
+		return reflect.ValueOf(word.True)
+	case *parse.DotNode:
+		return dot
+	case *parse.NilNode:
+		s.errorf("nil is not a command")
+	case *parse.NumberNode:
+		return s.idealConstant(word)
+	case *parse.StringNode:
+		return reflect.ValueOf(word.Text)
+	}
+	s.errorf("can't evaluate command %q", firstWord)
+	panic("not reached")
+}
+
+// idealConstant is called to return the value of a number in a context where
+// we don't know the type. In that case, the syntax of the number tells us
+// its type, and we use Go rules to resolve.  Note there is no such thing as
+// a uint ideal constant in this situation - the value must be of int type.
+func (s *state) idealConstant(constant *parse.NumberNode) reflect.Value {
+	// These are ideal constants but we don't know the type
+	// and we have no context.  (If it was a method argument,
+	// we'd know what we need.) The syntax guides us to some extent.
+	s.at(constant)
+	switch {
+	case constant.IsComplex:
+		return reflect.ValueOf(constant.Complex128) // incontrovertible.
+	case constant.IsFloat && !isHexConstant(constant.Text) && strings.IndexAny(constant.Text, ".eE") >= 0:
+		return reflect.ValueOf(constant.Float64)
+	case constant.IsInt:
+		n := int(constant.Int64)
+		if int64(n) != constant.Int64 {
+			s.errorf("%s overflows int", constant.Text)
+		}
+		return reflect.ValueOf(n)
+	case constant.IsUint:
+		s.errorf("%s overflows int", constant.Text)
+	}
+	return zero
+}
+
+func isHexConstant(s string) bool {
+	return len(s) > 2 && s[0] == '0' && (s[1] == 'x' || s[1] == 'X')
+}
+
+func (s *state) evalFieldNode(dot reflect.Value, field *parse.FieldNode, args []parse.Node, final reflect.Value) reflect.Value {
+	s.at(field)
+	return s.evalFieldChain(dot, dot, field, field.Ident, args, final)
+}
+
+func (s *state) evalChainNode(dot reflect.Value, chain *parse.ChainNode, args []parse.Node, final reflect.Value) reflect.Value {
+	s.at(chain)
+	// (pipe).Field1.Field2 has pipe as .Node, fields as .Field. Eval the pipeline, then the fields.
+	pipe := s.evalArg(dot, nil, chain.Node)
+	if len(chain.Field) == 0 {
+		s.errorf("internal error: no fields in evalChainNode")
+	}
+	return s.evalFieldChain(dot, pipe, chain, chain.Field, args, final)
+}
+
+func (s *state) evalVariableNode(dot reflect.Value, variable *parse.VariableNode, args []parse.Node, final reflect.Value) reflect.Value {
+	// $x.Field has $x as the first ident, Field as the second. Eval the var, then the fields.
+	s.at(variable)
+	value := s.varValue(variable.Ident[0])
+	if len(variable.Ident) == 1 {
+		s.notAFunction(args, final)
+		return value
+	}
+	return s.evalFieldChain(dot, value, variable, variable.Ident[1:], args, final)
+}
+
+// evalFieldChain evaluates .X.Y.Z possibly followed by arguments.
+// dot is the environment in which to evaluate arguments, while
+// receiver is the value being walked along the chain.
+func (s *state) evalFieldChain(dot, receiver reflect.Value, node parse.Node, ident []string, args []parse.Node, final reflect.Value) reflect.Value {
+	n := len(ident)
+	for i := 0; i < n-1; i++ {
+		receiver = s.evalField(dot, ident[i], node, nil, zero, receiver)
+	}
+	// Now if it's a method, it gets the arguments.
+	return s.evalField(dot, ident[n-1], node, args, final, receiver)
+}
+
+func (s *state) evalFunction(dot reflect.Value, node *parse.IdentifierNode, cmd parse.Node, args []parse.Node, final reflect.Value) reflect.Value {
+	s.at(node)
+	name := node.Ident
+	function, ok := findFunction(name, s.tmpl)
+	if !ok {
+		s.errorf("%q is not a defined function", name)
+	}
+	return s.evalCall(dot, function, cmd, name, args, final)
+}
+
+// evalField evaluates an expression like (.Field) or (.Field arg1 arg2).
+// The 'final' argument represents the return value from the preceding
+// value of the pipeline, if any.
+func (s *state) evalField(dot reflect.Value, fieldName string, node parse.Node, args []parse.Node, final, receiver reflect.Value) reflect.Value {
+	if !receiver.IsValid() {
+		return zero
+	}
+	typ := receiver.Type()
+	receiver, _ = indirect(receiver)
+	// Unless it's an interface, need to get to a value of type *T to guarantee
+	// we see all methods of T and *T.
+	ptr := receiver
+	if ptr.Kind() != reflect.Interface && ptr.CanAddr() {
+		ptr = ptr.Addr()
+	}
+	if method := ptr.MethodByName(fieldName); method.IsValid() {
+		return s.evalCall(dot, method, node, fieldName, args, final)
+	}
+	hasArgs := len(args) > 1 || final.IsValid()
+	// It's not a method; must be a field of a struct or an element of a map. The receiver must not be nil.
+	receiver, isNil := indirect(receiver)
+	if isNil {
+		s.errorf("nil pointer evaluating %s.%s", typ, fieldName)
+	}
+	switch receiver.Kind() {
+	case reflect.Struct:
+		tField, ok := receiver.Type().FieldByName(fieldName)
+		if ok {
+			field := receiver.FieldByIndex(tField.Index)
+			if tField.PkgPath != "" { // field is unexported
+				s.errorf("%s is an unexported field of struct type %s", fieldName, typ)
+			}
+			// If it's a function, we must call it.
+			if hasArgs {
+				s.errorf("%s has arguments but cannot be invoked as function", fieldName)
+			}
+			return field
+		}
+		s.errorf("%s is not a field of struct type %s", fieldName, typ)
+	case reflect.Map:
+		// If it's a map, attempt to use the field name as a key.
+		nameVal := reflect.ValueOf(fieldName)
+		if nameVal.Type().AssignableTo(receiver.Type().Key()) {
+			if hasArgs {
+				s.errorf("%s is not a method but has arguments", fieldName)
+			}
+			return receiver.MapIndex(nameVal)
+		}
+	}
+	s.errorf("can't evaluate field %s in type %s", fieldName, typ)
+	panic("not reached")
+}
+
+var (
+	errorType       = reflect.TypeOf((*error)(nil)).Elem()
+	fmtStringerType = reflect.TypeOf((*fmt.Stringer)(nil)).Elem()
+)
+
+// evalCall executes a function or method call. If it's a method, fun already has the receiver bound, so
+// it looks just like a function call.  The arg list, if non-nil, includes (in the manner of the shell), arg[0]
+// as the function itself.
+func (s *state) evalCall(dot, fun reflect.Value, node parse.Node, name string, args []parse.Node, final reflect.Value) reflect.Value {
+	if args != nil {
+		args = args[1:] // Zeroth arg is function name/node; not passed to function.
+	}
+	typ := fun.Type()
+	numIn := len(args)
+	if final.IsValid() {
+		numIn++
+	}
+	numFixed := len(args)
+	if typ.IsVariadic() {
+		numFixed = typ.NumIn() - 1 // last arg is the variadic one.
+		if numIn < numFixed {
+			s.errorf("wrong number of args for %s: want at least %d got %d", name, typ.NumIn()-1, len(args))
+		}
+	} else if numIn < typ.NumIn()-1 || !typ.IsVariadic() && numIn != typ.NumIn() {
+		s.errorf("wrong number of args for %s: want %d got %d", name, typ.NumIn(), len(args))
+	}
+	if !goodFunc(typ) {
+		// TODO: This could still be a confusing error; maybe goodFunc should provide info.
+		s.errorf("can't call method/function %q with %d results", name, typ.NumOut())
+	}
+	// Build the arg list.
+	argv := make([]reflect.Value, numIn)
+	// Args must be evaluated. Fixed args first.
+	i := 0
+	for ; i < numFixed && i < len(args); i++ {
+		argv[i] = s.evalArg(dot, typ.In(i), args[i])
+	}
+	// Now the ... args.
+	if typ.IsVariadic() {
+		argType := typ.In(typ.NumIn() - 1).Elem() // Argument is a slice.
+		for ; i < len(args); i++ {
+			argv[i] = s.evalArg(dot, argType, args[i])
+		}
+	}
+	// Add final value if necessary.
+	if final.IsValid() {
+		t := typ.In(typ.NumIn() - 1)
+		if typ.IsVariadic() {
+			t = t.Elem()
+		}
+		argv[i] = s.validateType(final, t)
+	}
+	result := fun.Call(argv)
+	// If we have an error that is not nil, stop execution and return that error to the caller.
+	if len(result) == 2 && !result[1].IsNil() {
+		s.at(node)
+		s.errorf("error calling %s: %s", name, result[1].Interface().(error))
+	}
+	return result[0]
+}
+
+// canBeNil reports whether an untyped nil can be assigned to the type. See reflect.Zero.
+func canBeNil(typ reflect.Type) bool {
+	switch typ.Kind() {
+	case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
+		return true
+	}
+	return false
+}
+
+// validateType guarantees that the value is valid and assignable to the type.
+func (s *state) validateType(value reflect.Value, typ reflect.Type) reflect.Value {
+	if !value.IsValid() {
+		if typ == nil || canBeNil(typ) {
+			// An untyped nil interface{}. Accept as a proper nil value.
+			return reflect.Zero(typ)
+		}
+		s.errorf("invalid value; expected %s", typ)
+	}
+	if typ != nil && !value.Type().AssignableTo(typ) {
+		if value.Kind() == reflect.Interface && !value.IsNil() {
+			value = value.Elem()
+			if value.Type().AssignableTo(typ) {
+				return value
+			}
+			// fallthrough
+		}
+		// Does one dereference or indirection work? We could do more, as we
+		// do with method receivers, but that gets messy and method receivers
+		// are much more constrained, so it makes more sense there than here.
+		// Besides, one is almost always all you need.
+		switch {
+		case value.Kind() == reflect.Ptr && value.Type().Elem().AssignableTo(typ):
+			value = value.Elem()
+			if !value.IsValid() {
+				s.errorf("dereference of nil pointer of type %s", typ)
+			}
+		case reflect.PtrTo(value.Type()).AssignableTo(typ) && value.CanAddr():
+			value = value.Addr()
+		default:
+			s.errorf("wrong type for value; expected %s; got %s", typ, value.Type())
+		}
+	}
+	return value
+}
+
+func (s *state) evalArg(dot reflect.Value, typ reflect.Type, n parse.Node) reflect.Value {
+	s.at(n)
+	switch arg := n.(type) {
+	case *parse.DotNode:
+		return s.validateType(dot, typ)
+	case *parse.NilNode:
+		if canBeNil(typ) {
+			return reflect.Zero(typ)
+		}
+		s.errorf("cannot assign nil to %s", typ)
+	case *parse.FieldNode:
+		return s.validateType(s.evalFieldNode(dot, arg, []parse.Node{n}, zero), typ)
+	case *parse.VariableNode:
+		return s.validateType(s.evalVariableNode(dot, arg, nil, zero), typ)
+	case *parse.PipeNode:
+		return s.validateType(s.evalPipeline(dot, arg), typ)
+	case *parse.IdentifierNode:
+		return s.evalFunction(dot, arg, arg, nil, zero)
+	case *parse.ChainNode:
+		return s.validateType(s.evalChainNode(dot, arg, nil, zero), typ)
+	}
+	switch typ.Kind() {
+	case reflect.Bool:
+		return s.evalBool(typ, n)
+	case reflect.Complex64, reflect.Complex128:
+		return s.evalComplex(typ, n)
+	case reflect.Float32, reflect.Float64:
+		return s.evalFloat(typ, n)
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return s.evalInteger(typ, n)
+	case reflect.Interface:
+		if typ.NumMethod() == 0 {
+			return s.evalEmptyInterface(dot, n)
+		}
+	case reflect.String:
+		return s.evalString(typ, n)
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return s.evalUnsignedInteger(typ, n)
+	}
+	s.errorf("can't handle %s for arg of type %s", n, typ)
+	panic("not reached")
+}
+
+func (s *state) evalBool(typ reflect.Type, n parse.Node) reflect.Value {
+	s.at(n)
+	if n, ok := n.(*parse.BoolNode); ok {
+		value := reflect.New(typ).Elem()
+		value.SetBool(n.True)
+		return value
+	}
+	s.errorf("expected bool; found %s", n)
+	panic("not reached")
+}
+
+func (s *state) evalString(typ reflect.Type, n parse.Node) reflect.Value {
+	s.at(n)
+	if n, ok := n.(*parse.StringNode); ok {
+		value := reflect.New(typ).Elem()
+		value.SetString(n.Text)
+		return value
+	}
+	s.errorf("expected string; found %s", n)
+	panic("not reached")
+}
+
+func (s *state) evalInteger(typ reflect.Type, n parse.Node) reflect.Value {
+	s.at(n)
+	if n, ok := n.(*parse.NumberNode); ok && n.IsInt {
+		value := reflect.New(typ).Elem()
+		value.SetInt(n.Int64)
+		return value
+	}
+	s.errorf("expected integer; found %s", n)
+	panic("not reached")
+}
+
+func (s *state) evalUnsignedInteger(typ reflect.Type, n parse.Node) reflect.Value {
+	s.at(n)
+	if n, ok := n.(*parse.NumberNode); ok && n.IsUint {
+		value := reflect.New(typ).Elem()
+		value.SetUint(n.Uint64)
+		return value
+	}
+	s.errorf("expected unsigned integer; found %s", n)
+	panic("not reached")
+}
+
+func (s *state) evalFloat(typ reflect.Type, n parse.Node) reflect.Value {
+	s.at(n)
+	if n, ok := n.(*parse.NumberNode); ok && n.IsFloat {
+		value := reflect.New(typ).Elem()
+		value.SetFloat(n.Float64)
+		return value
+	}
+	s.errorf("expected float; found %s", n)
+	panic("not reached")
+}
+
+func (s *state) evalComplex(typ reflect.Type, n parse.Node) reflect.Value {
+	if n, ok := n.(*parse.NumberNode); ok && n.IsComplex {
+		value := reflect.New(typ).Elem()
+		value.SetComplex(n.Complex128)
+		return value
+	}
+	s.errorf("expected complex; found %s", n)
+	panic("not reached")
+}
+
+func (s *state) evalEmptyInterface(dot reflect.Value, n parse.Node) reflect.Value {
+	s.at(n)
+	switch n := n.(type) {
+	case *parse.BoolNode:
+		return reflect.ValueOf(n.True)
+	case *parse.DotNode:
+		return dot
+	case *parse.FieldNode:
+		return s.evalFieldNode(dot, n, nil, zero)
+	case *parse.IdentifierNode:
+		return s.evalFunction(dot, n, n, nil, zero)
+	case *parse.NilNode:
+		// NilNode is handled in evalArg, the only place that calls here.
+		s.errorf("evalEmptyInterface: nil (can't happen)")
+	case *parse.NumberNode:
+		return s.idealConstant(n)
+	case *parse.StringNode:
+		return reflect.ValueOf(n.Text)
+	case *parse.VariableNode:
+		return s.evalVariableNode(dot, n, nil, zero)
+	case *parse.PipeNode:
+		return s.evalPipeline(dot, n)
+	}
+	s.errorf("can't handle assignment of %s to empty interface argument", n)
+	panic("not reached")
+}
+
+// indirect returns the item at the end of indirection, and a bool to indicate if it's nil.
+// We indirect through pointers and empty interfaces (only) because
+// non-empty interfaces have methods we might need.
+func indirect(v reflect.Value) (rv reflect.Value, isNil bool) {
+	for ; v.Kind() == reflect.Ptr || v.Kind() == reflect.Interface; v = v.Elem() {
+		if v.IsNil() {
+			return v, true
+		}
+		if v.Kind() == reflect.Interface && v.NumMethod() > 0 {
+			break
+		}
+	}
+	return v, false
+}
+
+// printValue writes the textual representation of the value to the output of
+// the template.
+func (s *state) printValue(n parse.Node, v reflect.Value) {
+	s.at(n)
+	iface, ok := printableValue(v)
+	if !ok {
+		s.errorf("can't print %s of type %s", n, v.Type())
+	}
+	fmt.Fprint(s.wr, iface)
+}
+
+// printableValue returns the, possibly indirected, interface value inside v that
+// is best for a call to formatted printer.
+func printableValue(v reflect.Value) (interface{}, bool) {
+	if v.Kind() == reflect.Ptr {
+		v, _ = indirect(v) // fmt.Fprint handles nil.
+	}
+	if !v.IsValid() {
+		return "<no value>", true
+	}
+
+	if !v.Type().Implements(errorType) && !v.Type().Implements(fmtStringerType) {
+		if v.CanAddr() && (reflect.PtrTo(v.Type()).Implements(errorType) || reflect.PtrTo(v.Type()).Implements(fmtStringerType)) {
+			v = v.Addr()
+		} else {
+			switch v.Kind() {
+			case reflect.Chan, reflect.Func:
+				return nil, false
+			}
+		}
+	}
+	return v.Interface(), true
+}
+
+// Types to help sort the keys in a map for reproducible output.
+
+type rvs []reflect.Value
+
+func (x rvs) Len() int      { return len(x) }
+func (x rvs) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
+
+type rvInts struct{ rvs }
+
+func (x rvInts) Less(i, j int) bool { return x.rvs[i].Int() < x.rvs[j].Int() }
+
+type rvUints struct{ rvs }
+
+func (x rvUints) Less(i, j int) bool { return x.rvs[i].Uint() < x.rvs[j].Uint() }
+
+type rvFloats struct{ rvs }
+
+func (x rvFloats) Less(i, j int) bool { return x.rvs[i].Float() < x.rvs[j].Float() }
+
+type rvStrings struct{ rvs }
+
+func (x rvStrings) Less(i, j int) bool { return x.rvs[i].String() < x.rvs[j].String() }
+
+// sortKeys sorts (if it can) the slice of reflect.Values, which is a slice of map keys.
+func sortKeys(v []reflect.Value) []reflect.Value {
+	if len(v) <= 1 {
+		return v
+	}
+	switch v[0].Kind() {
+	case reflect.Float32, reflect.Float64:
+		sort.Sort(rvFloats{v})
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		sort.Sort(rvInts{v})
+	case reflect.String:
+		sort.Sort(rvStrings{v})
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		sort.Sort(rvUints{v})
+	}
+	return v
+}

vendor/github.com/alecthomas/template/funcs.go

@@ -0,0 +1,598 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package template
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"net/url"
+	"reflect"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+// FuncMap is the type of the map defining the mapping from names to functions.
+// Each function must have either a single return value, or two return values of
+// which the second has type error. In that case, if the second (error)
+// return value evaluates to non-nil during execution, execution terminates and
+// Execute returns that error.
+type FuncMap map[string]interface{}
+
+var builtins = FuncMap{
+	"and":      and,
+	"call":     call,
+	"html":     HTMLEscaper,
+	"index":    index,
+	"js":       JSEscaper,
+	"len":      length,
+	"not":      not,
+	"or":       or,
+	"print":    fmt.Sprint,
+	"printf":   fmt.Sprintf,
+	"println":  fmt.Sprintln,
+	"urlquery": URLQueryEscaper,
+
+	// Comparisons
+	"eq": eq, // ==
+	"ge": ge, // >=
+	"gt": gt, // >
+	"le": le, // <=
+	"lt": lt, // <
+	"ne": ne, // !=
+}
+
+var builtinFuncs = createValueFuncs(builtins)
+
+// createValueFuncs turns a FuncMap into a map[string]reflect.Value
+func createValueFuncs(funcMap FuncMap) map[string]reflect.Value {
+	m := make(map[string]reflect.Value)
+	addValueFuncs(m, funcMap)
+	return m
+}
+
+// addValueFuncs adds to values the functions in funcs, converting them to reflect.Values.
+func addValueFuncs(out map[string]reflect.Value, in FuncMap) {
+	for name, fn := range in {
+		v := reflect.ValueOf(fn)
+		if v.Kind() != reflect.Func {
+			panic("value for " + name + " not a function")
+		}
+		if !goodFunc(v.Type()) {
+			panic(fmt.Errorf("can't install method/function %q with %d results", name, v.Type().NumOut()))
+		}
+		out[name] = v
+	}
+}
+
+// addFuncs adds to values the functions in funcs. It does no checking of the input -
+// call addValueFuncs first.
+func addFuncs(out, in FuncMap) {
+	for name, fn := range in {
+		out[name] = fn
+	}
+}
+
+// goodFunc checks that the function or method has the right result signature.
+func goodFunc(typ reflect.Type) bool {
+	// We allow functions with 1 result or 2 results where the second is an error.
+	switch {
+	case typ.NumOut() == 1:
+		return true
+	case typ.NumOut() == 2 && typ.Out(1) == errorType:
+		return true
+	}
+	return false
+}
+
+// findFunction looks for a function in the template, and global map.
+func findFunction(name string, tmpl *Template) (reflect.Value, bool) {
+	if tmpl != nil && tmpl.common != nil {
+		if fn := tmpl.execFuncs[name]; fn.IsValid() {
+			return fn, true
+		}
+	}
+	if fn := builtinFuncs[name]; fn.IsValid() {
+		return fn, true
+	}
+	return reflect.Value{}, false
+}
+
+// Indexing.
+
+// index returns the result of indexing its first argument by the following
+// arguments.  Thus "index x 1 2 3" is, in Go syntax, x[1][2][3]. Each
+// indexed item must be a map, slice, or array.
+func index(item interface{}, indices ...interface{}) (interface{}, error) {
+	v := reflect.ValueOf(item)
+	for _, i := range indices {
+		index := reflect.ValueOf(i)
+		var isNil bool
+		if v, isNil = indirect(v); isNil {
+			return nil, fmt.Errorf("index of nil pointer")
+		}
+		switch v.Kind() {
+		case reflect.Array, reflect.Slice, reflect.String:
+			var x int64
+			switch index.Kind() {
+			case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+				x = index.Int()
+			case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+				x = int64(index.Uint())
+			default:
+				return nil, fmt.Errorf("cannot index slice/array with type %s", index.Type())
+			}
+			if x < 0 || x >= int64(v.Len()) {
+				return nil, fmt.Errorf("index out of range: %d", x)
+			}
+			v = v.Index(int(x))
+		case reflect.Map:
+			if !index.IsValid() {
+				index = reflect.Zero(v.Type().Key())
+			}
+			if !index.Type().AssignableTo(v.Type().Key()) {
+				return nil, fmt.Errorf("%s is not index type for %s", index.Type(), v.Type())
+			}
+			if x := v.MapIndex(index); x.IsValid() {
+				v = x
+			} else {
+				v = reflect.Zero(v.Type().Elem())
+			}
+		default:
+			return nil, fmt.Errorf("can't index item of type %s", v.Type())
+		}
+	}
+	return v.Interface(), nil
+}
+
+// Length
+
+// length returns the length of the item, with an error if it has no defined length.
+func length(item interface{}) (int, error) {
+	v, isNil := indirect(reflect.ValueOf(item))
+	if isNil {
+		return 0, fmt.Errorf("len of nil pointer")
+	}
+	switch v.Kind() {
+	case reflect.Array, reflect.Chan, reflect.Map, reflect.Slice, reflect.String:
+		return v.Len(), nil
+	}
+	return 0, fmt.Errorf("len of type %s", v.Type())
+}
+
+// Function invocation
+
+// call returns the result of evaluating the first argument as a function.
+// The function must return 1 result, or 2 results, the second of which is an error.
+func call(fn interface{}, args ...interface{}) (interface{}, error) {
+	v := reflect.ValueOf(fn)
+	typ := v.Type()
+	if typ.Kind() != reflect.Func {
+		return nil, fmt.Errorf("non-function of type %s", typ)
+	}
+	if !goodFunc(typ) {
+		return nil, fmt.Errorf("function called with %d args; should be 1 or 2", typ.NumOut())
+	}
+	numIn := typ.NumIn()
+	var dddType reflect.Type
+	if typ.IsVariadic() {
+		if len(args) < numIn-1 {
+			return nil, fmt.Errorf("wrong number of args: got %d want at least %d", len(args), numIn-1)
+		}
+		dddType = typ.In(numIn - 1).Elem()
+	} else {
+		if len(args) != numIn {
+			return nil, fmt.Errorf("wrong number of args: got %d want %d", len(args), numIn)
+		}
+	}
+	argv := make([]reflect.Value, len(args))
+	for i, arg := range args {
+		value := reflect.ValueOf(arg)
+		// Compute the expected type. Clumsy because of variadics.
+		var argType reflect.Type
+		if !typ.IsVariadic() || i < numIn-1 {
+			argType = typ.In(i)
+		} else {
+			argType = dddType
+		}
+		if !value.IsValid() && canBeNil(argType) {
+			value = reflect.Zero(argType)
+		}
+		if !value.Type().AssignableTo(argType) {
+			return nil, fmt.Errorf("arg %d has type %s; should be %s", i, value.Type(), argType)
+		}
+		argv[i] = value
+	}
+	result := v.Call(argv)
+	if len(result) == 2 && !result[1].IsNil() {
+		return result[0].Interface(), result[1].Interface().(error)
+	}
+	return result[0].Interface(), nil
+}
+
+// Boolean logic.
+
+func truth(a interface{}) bool {
+	t, _ := isTrue(reflect.ValueOf(a))
+	return t
+}
+
+// and computes the Boolean AND of its arguments, returning
+// the first false argument it encounters, or the last argument.
+func and(arg0 interface{}, args ...interface{}) interface{} {
+	if !truth(arg0) {
+		return arg0
+	}
+	for i := range args {
+		arg0 = args[i]
+		if !truth(arg0) {
+			break
+		}
+	}
+	return arg0
+}
+
+// or computes the Boolean OR of its arguments, returning
+// the first true argument it encounters, or the last argument.
+func or(arg0 interface{}, args ...interface{}) interface{} {
+	if truth(arg0) {
+		return arg0
+	}
+	for i := range args {
+		arg0 = args[i]
+		if truth(arg0) {
+			break
+		}
+	}
+	return arg0
+}
+
+// not returns the Boolean negation of its argument.
+func not(arg interface{}) (truth bool) {
+	truth, _ = isTrue(reflect.ValueOf(arg))
+	return !truth
+}
+
+// Comparison.
+
+// TODO: Perhaps allow comparison between signed and unsigned integers.
+
+var (
+	errBadComparisonType = errors.New("invalid type for comparison")
+	errBadComparison     = errors.New("incompatible types for comparison")
+	errNoComparison      = errors.New("missing argument for comparison")
+)
+
+type kind int
+
+const (
+	invalidKind kind = iota
+	boolKind
+	complexKind
+	intKind
+	floatKind
+	integerKind
+	stringKind
+	uintKind
+)
+
+func basicKind(v reflect.Value) (kind, error) {
+	switch v.Kind() {
+	case reflect.Bool:
+		return boolKind, nil
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return intKind, nil
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return uintKind, nil
+	case reflect.Float32, reflect.Float64:
+		return floatKind, nil
+	case reflect.Complex64, reflect.Complex128:
+		return complexKind, nil
+	case reflect.String:
+		return stringKind, nil
+	}
+	return invalidKind, errBadComparisonType
+}
+
+// eq evaluates the comparison a == b || a == c || ...
+func eq(arg1 interface{}, arg2 ...interface{}) (bool, error) {
+	v1 := reflect.ValueOf(arg1)
+	k1, err := basicKind(v1)
+	if err != nil {
+		return false, err
+	}
+	if len(arg2) == 0 {
+		return false, errNoComparison
+	}
+	for _, arg := range arg2 {
+		v2 := reflect.ValueOf(arg)
+		k2, err := basicKind(v2)
+		if err != nil {
+			return false, err
+		}
+		truth := false
+		if k1 != k2 {
+			// Special case: Can compare integer values regardless of type's sign.
+			switch {
+			case k1 == intKind && k2 == uintKind:
+				truth = v1.Int() >= 0 && uint64(v1.Int()) == v2.Uint()
+			case k1 == uintKind && k2 == intKind:
+				truth = v2.Int() >= 0 && v1.Uint() == uint64(v2.Int())
+			default:
+				return false, errBadComparison
+			}
+		} else {
+			switch k1 {
+			case boolKind:
+				truth = v1.Bool() == v2.Bool()
+			case complexKind:
+				truth = v1.Complex() == v2.Complex()
+			case floatKind:
+				truth = v1.Float() == v2.Float()
+			case intKind:
+				truth = v1.Int() == v2.Int()
+			case stringKind:
+				truth = v1.String() == v2.String()
+			case uintKind:
+				truth = v1.Uint() == v2.Uint()
+			default:
+				panic("invalid kind")
+			}
+		}
+		if truth {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
+// ne evaluates the comparison a != b.
+func ne(arg1, arg2 interface{}) (bool, error) {
+	// != is the inverse of ==.
+	equal, err := eq(arg1, arg2)
+	return !equal, err
+}
+
+// lt evaluates the comparison a < b.
+func lt(arg1, arg2 interface{}) (bool, error) {
+	v1 := reflect.ValueOf(arg1)
+	k1, err := basicKind(v1)
+	if err != nil {
+		return false, err
+	}
+	v2 := reflect.ValueOf(arg2)
+	k2, err := basicKind(v2)
+	if err != nil {
+		return false, err
+	}
+	truth := false
+	if k1 != k2 {
+		// Special case: Can compare integer values regardless of type's sign.
+		switch {
+		case k1 == intKind && k2 == uintKind:
+			truth = v1.Int() < 0 || uint64(v1.Int()) < v2.Uint()
+		case k1 == uintKind && k2 == intKind:
+			truth = v2.Int() >= 0 && v1.Uint() < uint64(v2.Int())
+		default:
+			return false, errBadComparison
+		}
+	} else {
+		switch k1 {
+		case boolKind, complexKind:
+			return false, errBadComparisonType
+		case floatKind:
+			truth = v1.Float() < v2.Float()
+		case intKind:
+			truth = v1.Int() < v2.Int()
+		case stringKind:
+			truth = v1.String() < v2.String()
+		case uintKind:
+			truth = v1.Uint() < v2.Uint()
+		default:
+			panic("invalid kind")
+		}
+	}
+	return truth, nil
+}
+
+// le evaluates the comparison <= b.
+func le(arg1, arg2 interface{}) (bool, error) {
+	// <= is < or ==.
+	lessThan, err := lt(arg1, arg2)
+	if lessThan || err != nil {
+		return lessThan, err
+	}
+	return eq(arg1, arg2)
+}
+
+// gt evaluates the comparison a > b.
+func gt(arg1, arg2 interface{}) (bool, error) {
+	// > is the inverse of <=.
+	lessOrEqual, err := le(arg1, arg2)
+	if err != nil {
+		return false, err
+	}
+	return !lessOrEqual, nil
+}
+
+// ge evaluates the comparison a >= b.
+func ge(arg1, arg2 interface{}) (bool, error) {
+	// >= is the inverse of <.
+	lessThan, err := lt(arg1, arg2)
+	if err != nil {
+		return false, err
+	}
+	return !lessThan, nil
+}
+
+// HTML escaping.
+
+var (
+	htmlQuot = []byte("&#34;") // shorter than "&quot;"
+	htmlApos = []byte("&#39;") // shorter than "&apos;" and apos was not in HTML until HTML5
+	htmlAmp  = []byte("&amp;")
+	htmlLt   = []byte("&lt;")
+	htmlGt   = []byte("&gt;")
+)
+
+// HTMLEscape writes to w the escaped HTML equivalent of the plain text data b.
+func HTMLEscape(w io.Writer, b []byte) {
+	last := 0
+	for i, c := range b {
+		var html []byte
+		switch c {
+		case '"':
+			html = htmlQuot
+		case '\'':
+			html = htmlApos
+		case '&':
+			html = htmlAmp
+		case '<':
+			html = htmlLt
+		case '>':
+			html = htmlGt
+		default:
+			continue
+		}
+		w.Write(b[last:i])
+		w.Write(html)
+		last = i + 1
+	}
+	w.Write(b[last:])
+}
+
+// HTMLEscapeString returns the escaped HTML equivalent of the plain text data s.
+func HTMLEscapeString(s string) string {
+	// Avoid allocation if we can.
+	if strings.IndexAny(s, `'"&<>`) < 0 {
+		return s
+	}
+	var b bytes.Buffer
+	HTMLEscape(&b, []byte(s))
+	return b.String()
+}
+
+// HTMLEscaper returns the escaped HTML equivalent of the textual
+// representation of its arguments.
+func HTMLEscaper(args ...interface{}) string {
+	return HTMLEscapeString(evalArgs(args))
+}
+
+// JavaScript escaping.
+
+var (
+	jsLowUni = []byte(`\u00`)
+	hex      = []byte("0123456789ABCDEF")
+
+	jsBackslash = []byte(`\\`)
+	jsApos      = []byte(`\'`)
+	jsQuot      = []byte(`\"`)
+	jsLt        = []byte(`\x3C`)
+	jsGt        = []byte(`\x3E`)
+)
+
+// JSEscape writes to w the escaped JavaScript equivalent of the plain text data b.
+func JSEscape(w io.Writer, b []byte) {
+	last := 0
+	for i := 0; i < len(b); i++ {
+		c := b[i]
+
+		if !jsIsSpecial(rune(c)) {
+			// fast path: nothing to do
+			continue
+		}
+		w.Write(b[last:i])
+
+		if c < utf8.RuneSelf {
+			// Quotes, slashes and angle brackets get quoted.
+			// Control characters get written as \u00XX.
+			switch c {
+			case '\\':
+				w.Write(jsBackslash)
+			case '\'':
+				w.Write(jsApos)
+			case '"':
+				w.Write(jsQuot)
+			case '<':
+				w.Write(jsLt)
+			case '>':
+				w.Write(jsGt)
+			default:
+				w.Write(jsLowUni)
+				t, b := c>>4, c&0x0f
+				w.Write(hex[t : t+1])
+				w.Write(hex[b : b+1])
+			}
+		} else {
+			// Unicode rune.
+			r, size := utf8.DecodeRune(b[i:])
+			if unicode.IsPrint(r) {
+				w.Write(b[i : i+size])
+			} else {
+				fmt.Fprintf(w, "\\u%04X", r)
+			}
+			i += size - 1
+		}
+		last = i + 1
+	}
+	w.Write(b[last:])
+}
+
+// JSEscapeString returns the escaped JavaScript equivalent of the plain text data s.
+func JSEscapeString(s string) string {
+	// Avoid allocation if we can.
+	if strings.IndexFunc(s, jsIsSpecial) < 0 {
+		return s
+	}
+	var b bytes.Buffer
+	JSEscape(&b, []byte(s))
+	return b.String()
+}
+
+func jsIsSpecial(r rune) bool {
+	switch r {
+	case '\\', '\'', '"', '<', '>':
+		return true
+	}
+	return r < ' ' || utf8.RuneSelf <= r
+}
+
+// JSEscaper returns the escaped JavaScript equivalent of the textual
+// representation of its arguments.
+func JSEscaper(args ...interface{}) string {
+	return JSEscapeString(evalArgs(args))
+}
+
+// URLQueryEscaper returns the escaped value of the textual representation of
+// its arguments in a form suitable for embedding in a URL query.
+func URLQueryEscaper(args ...interface{}) string {
+	return url.QueryEscape(evalArgs(args))
+}
+
+// evalArgs formats the list of arguments into a string. It is therefore equivalent to
+//	fmt.Sprint(args...)
+// except that each argument is indirected (if a pointer), as required,
+// using the same rules as the default string evaluation during template
+// execution.
+func evalArgs(args []interface{}) string {
+	ok := false
+	var s string
+	// Fast path for simple common case.
+	if len(args) == 1 {
+		s, ok = args[0].(string)
+	}
+	if !ok {
+		for i, arg := range args {
+			a, ok := printableValue(reflect.ValueOf(arg))
+			if ok {
+				args[i] = a
+			} // else left fmt do its thing
+		}
+		s = fmt.Sprint(args...)
+	}
+	return s
+}

vendor/github.com/alecthomas/template/helper.go

@@ -0,0 +1,108 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Helper functions to make constructing templates easier.
+
+package template
+
+import (
+	"fmt"
+	"io/ioutil"
+	"path/filepath"
+)
+
+// Functions and methods to parse templates.
+
+// Must is a helper that wraps a call to a function returning (*Template, error)
+// and panics if the error is non-nil. It is intended for use in variable
+// initializations such as
+//	var t = template.Must(template.New("name").Parse("text"))
+func Must(t *Template, err error) *Template {
+	if err != nil {
+		panic(err)
+	}
+	return t
+}
+
+// ParseFiles creates a new Template and parses the template definitions from
+// the named files. The returned template's name will have the (base) name and
+// (parsed) contents of the first file. There must be at least one file.
+// If an error occurs, parsing stops and the returned *Template is nil.
+func ParseFiles(filenames ...string) (*Template, error) {
+	return parseFiles(nil, filenames...)
+}
+
+// ParseFiles parses the named files and associates the resulting templates with
+// t. If an error occurs, parsing stops and the returned template is nil;
+// otherwise it is t. There must be at least one file.
+func (t *Template) ParseFiles(filenames ...string) (*Template, error) {
+	return parseFiles(t, filenames...)
+}
+
+// parseFiles is the helper for the method and function. If the argument
+// template is nil, it is created from the first file.
+func parseFiles(t *Template, filenames ...string) (*Template, error) {
+	if len(filenames) == 0 {
+		// Not really a problem, but be consistent.
+		return nil, fmt.Errorf("template: no files named in call to ParseFiles")
+	}
+	for _, filename := range filenames {
+		b, err := ioutil.ReadFile(filename)
+		if err != nil {
+			return nil, err
+		}
+		s := string(b)
+		name := filepath.Base(filename)
+		// First template becomes return value if not already defined,
+		// and we use that one for subsequent New calls to associate
+		// all the templates together. Also, if this file has the same name
+		// as t, this file becomes the contents of t, so
+		//  t, err := New(name).Funcs(xxx).ParseFiles(name)
+		// works. Otherwise we create a new template associated with t.
+		var tmpl *Template
+		if t == nil {
+			t = New(name)
+		}
+		if name == t.Name() {
+			tmpl = t
+		} else {
+			tmpl = t.New(name)
+		}
+		_, err = tmpl.Parse(s)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return t, nil
+}
+
+// ParseGlob creates a new Template and parses the template definitions from the
+// files identified by the pattern, which must match at least one file. The
+// returned template will have the (base) name and (parsed) contents of the
+// first file matched by the pattern. ParseGlob is equivalent to calling
+// ParseFiles with the list of files matched by the pattern.
+func ParseGlob(pattern string) (*Template, error) {
+	return parseGlob(nil, pattern)
+}
+
+// ParseGlob parses the template definitions in the files identified by the
+// pattern and associates the resulting templates with t. The pattern is
+// processed by filepath.Glob and must match at least one file. ParseGlob is
+// equivalent to calling t.ParseFiles with the list of files matched by the
+// pattern.
+func (t *Template) ParseGlob(pattern string) (*Template, error) {
+	return parseGlob(t, pattern)
+}
+
+// parseGlob is the implementation of the function and method ParseGlob.
+func parseGlob(t *Template, pattern string) (*Template, error) {
+	filenames, err := filepath.Glob(pattern)
+	if err != nil {
+		return nil, err
+	}
+	if len(filenames) == 0 {
+		return nil, fmt.Errorf("template: pattern matches no files: %#q", pattern)
+	}
+	return parseFiles(t, filenames...)
+}

vendor/github.com/alecthomas/template/parse/lex.go

@@ -0,0 +1,556 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package parse
+
+import (
+	"fmt"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+// item represents a token or text string returned from the scanner.
+type item struct {
+	typ itemType // The type of this item.
+	pos Pos      // The starting position, in bytes, of this item in the input string.
+	val string   // The value of this item.
+}
+
+func (i item) String() string {
+	switch {
+	case i.typ == itemEOF:
+		return "EOF"
+	case i.typ == itemError:
+		return i.val
+	case i.typ > itemKeyword:
+		return fmt.Sprintf("<%s>", i.val)
+	case len(i.val) > 10:
+		return fmt.Sprintf("%.10q...", i.val)
+	}
+	return fmt.Sprintf("%q", i.val)
+}
+
+// itemType identifies the type of lex items.
+type itemType int
+
+const (
+	itemError        itemType = iota // error occurred; value is text of error
+	itemBool                         // boolean constant
+	itemChar                         // printable ASCII character; grab bag for comma etc.
+	itemCharConstant                 // character constant
+	itemComplex                      // complex constant (1+2i); imaginary is just a number
+	itemColonEquals                  // colon-equals (':=') introducing a declaration
+	itemEOF
+	itemField        // alphanumeric identifier starting with '.'
+	itemIdentifier   // alphanumeric identifier not starting with '.'
+	itemLeftDelim    // left action delimiter
+	itemLeftParen    // '(' inside action
+	itemNumber       // simple number, including imaginary
+	itemPipe         // pipe symbol
+	itemRawString    // raw quoted string (includes quotes)
+	itemRightDelim   // right action delimiter
+	itemElideNewline // elide newline after right delim
+	itemRightParen   // ')' inside action
+	itemSpace        // run of spaces separating arguments
+	itemString       // quoted string (includes quotes)
+	itemText         // plain text
+	itemVariable     // variable starting with '$', such as '$' or  '$1' or '$hello'
+	// Keywords appear after all the rest.
+	itemKeyword  // used only to delimit the keywords
+	itemDot      // the cursor, spelled '.'
+	itemDefine   // define keyword
+	itemElse     // else keyword
+	itemEnd      // end keyword
+	itemIf       // if keyword
+	itemNil      // the untyped nil constant, easiest to treat as a keyword
+	itemRange    // range keyword
+	itemTemplate // template keyword
+	itemWith     // with keyword
+)
+
+var key = map[string]itemType{
+	".":        itemDot,
+	"define":   itemDefine,
+	"else":     itemElse,
+	"end":      itemEnd,
+	"if":       itemIf,
+	"range":    itemRange,
+	"nil":      itemNil,
+	"template": itemTemplate,
+	"with":     itemWith,
+}
+
+const eof = -1
+
+// stateFn represents the state of the scanner as a function that returns the next state.
+type stateFn func(*lexer) stateFn
+
+// lexer holds the state of the scanner.
+type lexer struct {
+	name       string    // the name of the input; used only for error reports
+	input      string    // the string being scanned
+	leftDelim  string    // start of action
+	rightDelim string    // end of action
+	state      stateFn   // the next lexing function to enter
+	pos        Pos       // current position in the input
+	start      Pos       // start position of this item
+	width      Pos       // width of last rune read from input
+	lastPos    Pos       // position of most recent item returned by nextItem
+	items      chan item // channel of scanned items
+	parenDepth int       // nesting depth of ( ) exprs
+}
+
+// next returns the next rune in the input.
+func (l *lexer) next() rune {
+	if int(l.pos) >= len(l.input) {
+		l.width = 0
+		return eof
+	}
+	r, w := utf8.DecodeRuneInString(l.input[l.pos:])
+	l.width = Pos(w)
+	l.pos += l.width
+	return r
+}
+
+// peek returns but does not consume the next rune in the input.
+func (l *lexer) peek() rune {
+	r := l.next()
+	l.backup()
+	return r
+}
+
+// backup steps back one rune. Can only be called once per call of next.
+func (l *lexer) backup() {
+	l.pos -= l.width
+}
+
+// emit passes an item back to the client.
+func (l *lexer) emit(t itemType) {
+	l.items <- item{t, l.start, l.input[l.start:l.pos]}
+	l.start = l.pos
+}
+
+// ignore skips over the pending input before this point.
+func (l *lexer) ignore() {
+	l.start = l.pos
+}
+
+// accept consumes the next rune if it's from the valid set.
+func (l *lexer) accept(valid string) bool {
+	if strings.IndexRune(valid, l.next()) >= 0 {
+		return true
+	}
+	l.backup()
+	return false
+}
+
+// acceptRun consumes a run of runes from the valid set.
+func (l *lexer) acceptRun(valid string) {
+	for strings.IndexRune(valid, l.next()) >= 0 {
+	}
+	l.backup()
+}
+
+// lineNumber reports which line we're on, based on the position of
+// the previous item returned by nextItem. Doing it this way
+// means we don't have to worry about peek double counting.
+func (l *lexer) lineNumber() int {
+	return 1 + strings.Count(l.input[:l.lastPos], "\n")
+}
+
+// errorf returns an error token and terminates the scan by passing
+// back a nil pointer that will be the next state, terminating l.nextItem.
+func (l *lexer) errorf(format string, args ...interface{}) stateFn {
+	l.items <- item{itemError, l.start, fmt.Sprintf(format, args...)}
+	return nil
+}
+
+// nextItem returns the next item from the input.
+func (l *lexer) nextItem() item {
+	item := <-l.items
+	l.lastPos = item.pos
+	return item
+}
+
+// lex creates a new scanner for the input string.
+func lex(name, input, left, right string) *lexer {
+	if left == "" {
+		left = leftDelim
+	}
+	if right == "" {
+		right = rightDelim
+	}
+	l := &lexer{
+		name:       name,
+		input:      input,
+		leftDelim:  left,
+		rightDelim: right,
+		items:      make(chan item),
+	}
+	go l.run()
+	return l
+}
+
+// run runs the state machine for the lexer.
+func (l *lexer) run() {
+	for l.state = lexText; l.state != nil; {
+		l.state = l.state(l)
+	}
+}
+
+// state functions
+
+const (
+	leftDelim    = "{{"
+	rightDelim   = "}}"
+	leftComment  = "/*"
+	rightComment = "*/"
+)
+
+// lexText scans until an opening action delimiter, "{{".
+func lexText(l *lexer) stateFn {
+	for {
+		if strings.HasPrefix(l.input[l.pos:], l.leftDelim) {
+			if l.pos > l.start {
+				l.emit(itemText)
+			}
+			return lexLeftDelim
+		}
+		if l.next() == eof {
+			break
+		}
+	}
+	// Correctly reached EOF.
+	if l.pos > l.start {
+		l.emit(itemText)
+	}
+	l.emit(itemEOF)
+	return nil
+}
+
+// lexLeftDelim scans the left delimiter, which is known to be present.
+func lexLeftDelim(l *lexer) stateFn {
+	l.pos += Pos(len(l.leftDelim))
+	if strings.HasPrefix(l.input[l.pos:], leftComment) {
+		return lexComment
+	}
+	l.emit(itemLeftDelim)
+	l.parenDepth = 0
+	return lexInsideAction
+}
+
+// lexComment scans a comment. The left comment marker is known to be present.
+func lexComment(l *lexer) stateFn {
+	l.pos += Pos(len(leftComment))
+	i := strings.Index(l.input[l.pos:], rightComment)
+	if i < 0 {
+		return l.errorf("unclosed comment")
+	}
+	l.pos += Pos(i + len(rightComment))
+	if !strings.HasPrefix(l.input[l.pos:], l.rightDelim) {
+		return l.errorf("comment ends before closing delimiter")
+
+	}
+	l.pos += Pos(len(l.rightDelim))
+	l.ignore()
+	return lexText
+}
+
+// lexRightDelim scans the right delimiter, which is known to be present.
+func lexRightDelim(l *lexer) stateFn {
+	l.pos += Pos(len(l.rightDelim))
+	l.emit(itemRightDelim)
+	if l.peek() == '\\' {
+		l.pos++
+		l.emit(itemElideNewline)
+	}
+	return lexText
+}
+
+// lexInsideAction scans the elements inside action delimiters.
+func lexInsideAction(l *lexer) stateFn {
+	// Either number, quoted string, or identifier.
+	// Spaces separate arguments; runs of spaces turn into itemSpace.
+	// Pipe symbols separate and are emitted.
+	if strings.HasPrefix(l.input[l.pos:], l.rightDelim+"\\") || strings.HasPrefix(l.input[l.pos:], l.rightDelim) {
+		if l.parenDepth == 0 {
+			return lexRightDelim
+		}
+		return l.errorf("unclosed left paren")
+	}
+	switch r := l.next(); {
+	case r == eof || isEndOfLine(r):
+		return l.errorf("unclosed action")
+	case isSpace(r):
+		return lexSpace
+	case r == ':':
+		if l.next() != '=' {
+			return l.errorf("expected :=")
+		}
+		l.emit(itemColonEquals)
+	case r == '|':
+		l.emit(itemPipe)
+	case r == '"':
+		return lexQuote
+	case r == '`':
+		return lexRawQuote
+	case r == '$':
+		return lexVariable
+	case r == '\'':
+		return lexChar
+	case r == '.':
+		// special look-ahead for ".field" so we don't break l.backup().
+		if l.pos < Pos(len(l.input)) {
+			r := l.input[l.pos]
+			if r < '0' || '9' < r {
+				return lexField
+			}
+		}
+		fallthrough // '.' can start a number.
+	case r == '+' || r == '-' || ('0' <= r && r <= '9'):
+		l.backup()
+		return lexNumber
+	case isAlphaNumeric(r):
+		l.backup()
+		return lexIdentifier
+	case r == '(':
+		l.emit(itemLeftParen)
+		l.parenDepth++
+		return lexInsideAction
+	case r == ')':
+		l.emit(itemRightParen)
+		l.parenDepth--
+		if l.parenDepth < 0 {
+			return l.errorf("unexpected right paren %#U", r)
+		}
+		return lexInsideAction
+	case r <= unicode.MaxASCII && unicode.IsPrint(r):
+		l.emit(itemChar)
+		return lexInsideAction
+	default:
+		return l.errorf("unrecognized character in action: %#U", r)
+	}
+	return lexInsideAction
+}
+
+// lexSpace scans a run of space characters.
+// One space has already been seen.
+func lexSpace(l *lexer) stateFn {
+	for isSpace(l.peek()) {
+		l.next()
+	}
+	l.emit(itemSpace)
+	return lexInsideAction
+}
+
+// lexIdentifier scans an alphanumeric.
+func lexIdentifier(l *lexer) stateFn {
+Loop:
+	for {
+		switch r := l.next(); {
+		case isAlphaNumeric(r):
+			// absorb.
+		default:
+			l.backup()
+			word := l.input[l.start:l.pos]
+			if !l.atTerminator() {
+				return l.errorf("bad character %#U", r)
+			}
+			switch {
+			case key[word] > itemKeyword:
+				l.emit(key[word])
+			case word[0] == '.':
+				l.emit(itemField)
+			case word == "true", word == "false":
+				l.emit(itemBool)
+			default:
+				l.emit(itemIdentifier)
+			}
+			break Loop
+		}
+	}
+	return lexInsideAction
+}
+
+// lexField scans a field: .Alphanumeric.
+// The . has been scanned.
+func lexField(l *lexer) stateFn {
+	return lexFieldOrVariable(l, itemField)
+}
+
+// lexVariable scans a Variable: $Alphanumeric.
+// The $ has been scanned.
+func lexVariable(l *lexer) stateFn {
+	if l.atTerminator() { // Nothing interesting follows -> "$".
+		l.emit(itemVariable)
+		return lexInsideAction
+	}
+	return lexFieldOrVariable(l, itemVariable)
+}
+
+// lexVariable scans a field or variable: [.$]Alphanumeric.
+// The . or $ has been scanned.
+func lexFieldOrVariable(l *lexer, typ itemType) stateFn {
+	if l.atTerminator() { // Nothing interesting follows -> "." or "$".
+		if typ == itemVariable {
+			l.emit(itemVariable)
+		} else {
+			l.emit(itemDot)
+		}
+		return lexInsideAction
+	}
+	var r rune
+	for {
+		r = l.next()
+		if !isAlphaNumeric(r) {
+			l.backup()
+			break
+		}
+	}
+	if !l.atTerminator() {
+		return l.errorf("bad character %#U", r)
+	}
+	l.emit(typ)
+	return lexInsideAction
+}
+
+// atTerminator reports whether the input is at valid termination character to
+// appear after an identifier. Breaks .X.Y into two pieces. Also catches cases
+// like "$x+2" not being acceptable without a space, in case we decide one
+// day to implement arithmetic.
+func (l *lexer) atTerminator() bool {
+	r := l.peek()
+	if isSpace(r) || isEndOfLine(r) {
+		return true
+	}
+	switch r {
+	case eof, '.', ',', '|', ':', ')', '(':
+		return true
+	}
+	// Does r start the delimiter? This can be ambiguous (with delim=="//", $x/2 will
+	// succeed but should fail) but only in extremely rare cases caused by willfully
+	// bad choice of delimiter.
+	if rd, _ := utf8.DecodeRuneInString(l.rightDelim); rd == r {
+		return true
+	}
+	return false
+}
+
+// lexChar scans a character constant. The initial quote is already
+// scanned. Syntax checking is done by the parser.
+func lexChar(l *lexer) stateFn {
+Loop:
+	for {
+		switch l.next() {
+		case '\\':
+			if r := l.next(); r != eof && r != '\n' {
+				break
+			}
+			fallthrough
+		case eof, '\n':
+			return l.errorf("unterminated character constant")
+		case '\'':
+			break Loop
+		}
+	}
+	l.emit(itemCharConstant)
+	return lexInsideAction
+}
+
+// lexNumber scans a number: decimal, octal, hex, float, or imaginary. This
+// isn't a perfect number scanner - for instance it accepts "." and "0x0.2"
+// and "089" - but when it's wrong the input is invalid and the parser (via
+// strconv) will notice.
+func lexNumber(l *lexer) stateFn {
+	if !l.scanNumber() {
+		return l.errorf("bad number syntax: %q", l.input[l.start:l.pos])
+	}
+	if sign := l.peek(); sign == '+' || sign == '-' {
+		// Complex: 1+2i. No spaces, must end in 'i'.
+		if !l.scanNumber() || l.input[l.pos-1] != 'i' {
+			return l.errorf("bad number syntax: %q", l.input[l.start:l.pos])
+		}
+		l.emit(itemComplex)
+	} else {
+		l.emit(itemNumber)
+	}
+	return lexInsideAction
+}
+
+func (l *lexer) scanNumber() bool {
+	// Optional leading sign.
+	l.accept("+-")
+	// Is it hex?
+	digits := "0123456789"
+	if l.accept("0") && l.accept("xX") {
+		digits = "0123456789abcdefABCDEF"
+	}
+	l.acceptRun(digits)
+	if l.accept(".") {
+		l.acceptRun(digits)
+	}
+	if l.accept("eE") {
+		l.accept("+-")
+		l.acceptRun("0123456789")
+	}
+	// Is it imaginary?
+	l.accept("i")
+	// Next thing mustn't be alphanumeric.
+	if isAlphaNumeric(l.peek()) {
+		l.next()
+		return false
+	}
+	return true
+}
+
+// lexQuote scans a quoted string.
+func lexQuote(l *lexer) stateFn {
+Loop:
+	for {
+		switch l.next() {
+		case '\\':
+			if r := l.next(); r != eof && r != '\n' {
+				break
+			}
+			fallthrough
+		case eof, '\n':
+			return l.errorf("unterminated quoted string")
+		case '"':
+			break Loop
+		}
+	}
+	l.emit(itemString)
+	return lexInsideAction
+}
+
+// lexRawQuote scans a raw quoted string.
+func lexRawQuote(l *lexer) stateFn {
+Loop:
+	for {
+		switch l.next() {
+		case eof, '\n':
+			return l.errorf("unterminated raw quoted string")
+		case '`':
+			break Loop
+		}
+	}
+	l.emit(itemRawString)
+	return lexInsideAction
+}
+
+// isSpace reports whether r is a space character.
+func isSpace(r rune) bool {
+	return r == ' ' || r == '\t'
+}
+
+// isEndOfLine reports whether r is an end-of-line character.
+func isEndOfLine(r rune) bool {
+	return r == '\r' || r == '\n'
+}
+
+// isAlphaNumeric reports whether r is an alphabetic, digit, or underscore.
+func isAlphaNumeric(r rune) bool {
+	return r == '_' || unicode.IsLetter(r) || unicode.IsDigit(r)
+}

vendor/github.com/alecthomas/template/parse/node.go

@@ -0,0 +1,834 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Parse nodes.
+
+package parse
+
+import (
+	"bytes"
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+var textFormat = "%s" // Changed to "%q" in tests for better error messages.
+
+// A Node is an element in the parse tree. The interface is trivial.
+// The interface contains an unexported method so that only
+// types local to this package can satisfy it.
+type Node interface {
+	Type() NodeType
+	String() string
+	// Copy does a deep copy of the Node and all its components.
+	// To avoid type assertions, some XxxNodes also have specialized
+	// CopyXxx methods that return *XxxNode.
+	Copy() Node
+	Position() Pos // byte position of start of node in full original input string
+	// tree returns the containing *Tree.
+	// It is unexported so all implementations of Node are in this package.
+	tree() *Tree
+}
+
+// NodeType identifies the type of a parse tree node.
+type NodeType int
+
+// Pos represents a byte position in the original input text from which
+// this template was parsed.
+type Pos int
+
+func (p Pos) Position() Pos {
+	return p
+}
+
+// Type returns itself and provides an easy default implementation
+// for embedding in a Node. Embedded in all non-trivial Nodes.
+func (t NodeType) Type() NodeType {
+	return t
+}
+
+const (
+	NodeText       NodeType = iota // Plain text.
+	NodeAction                     // A non-control action such as a field evaluation.
+	NodeBool                       // A boolean constant.
+	NodeChain                      // A sequence of field accesses.
+	NodeCommand                    // An element of a pipeline.
+	NodeDot                        // The cursor, dot.
+	nodeElse                       // An else action. Not added to tree.
+	nodeEnd                        // An end action. Not added to tree.
+	NodeField                      // A field or method name.
+	NodeIdentifier                 // An identifier; always a function name.
+	NodeIf                         // An if action.
+	NodeList                       // A list of Nodes.
+	NodeNil                        // An untyped nil constant.
+	NodeNumber                     // A numerical constant.
+	NodePipe                       // A pipeline of commands.
+	NodeRange                      // A range action.
+	NodeString                     // A string constant.
+	NodeTemplate                   // A template invocation action.
+	NodeVariable                   // A $ variable.
+	NodeWith                       // A with action.
+)
+
+// Nodes.
+
+// ListNode holds a sequence of nodes.
+type ListNode struct {
+	NodeType
+	Pos
+	tr    *Tree
+	Nodes []Node // The element nodes in lexical order.
+}
+
+func (t *Tree) newList(pos Pos) *ListNode {
+	return &ListNode{tr: t, NodeType: NodeList, Pos: pos}
+}
+
+func (l *ListNode) append(n Node) {
+	l.Nodes = append(l.Nodes, n)
+}
+
+func (l *ListNode) tree() *Tree {
+	return l.tr
+}
+
+func (l *ListNode) String() string {
+	b := new(bytes.Buffer)
+	for _, n := range l.Nodes {
+		fmt.Fprint(b, n)
+	}
+	return b.String()
+}
+
+func (l *ListNode) CopyList() *ListNode {
+	if l == nil {
+		return l
+	}
+	n := l.tr.newList(l.Pos)
+	for _, elem := range l.Nodes {
+		n.append(elem.Copy())
+	}
+	return n
+}
+
+func (l *ListNode) Copy() Node {
+	return l.CopyList()
+}
+
+// TextNode holds plain text.
+type TextNode struct {
+	NodeType
+	Pos
+	tr   *Tree
+	Text []byte // The text; may span newlines.
+}
+
+func (t *Tree) newText(pos Pos, text string) *TextNode {
+	return &TextNode{tr: t, NodeType: NodeText, Pos: pos, Text: []byte(text)}
+}
+
+func (t *TextNode) String() string {
+	return fmt.Sprintf(textFormat, t.Text)
+}
+
+func (t *TextNode) tree() *Tree {
+	return t.tr
+}
+
+func (t *TextNode) Copy() Node {
+	return &TextNode{tr: t.tr, NodeType: NodeText, Pos: t.Pos, Text: append([]byte{}, t.Text...)}
+}
+
+// PipeNode holds a pipeline with optional declaration
+type PipeNode struct {
+	NodeType
+	Pos
+	tr   *Tree
+	Line int             // The line number in the input (deprecated; kept for compatibility)
+	Decl []*VariableNode // Variable declarations in lexical order.
+	Cmds []*CommandNode  // The commands in lexical order.
+}
+
+func (t *Tree) newPipeline(pos Pos, line int, decl []*VariableNode) *PipeNode {
+	return &PipeNode{tr: t, NodeType: NodePipe, Pos: pos, Line: line, Decl: decl}
+}
+
+func (p *PipeNode) append(command *CommandNode) {
+	p.Cmds = append(p.Cmds, command)
+}
+
+func (p *PipeNode) String() string {
+	s := ""
+	if len(p.Decl) > 0 {
+		for i, v := range p.Decl {
+			if i > 0 {
+				s += ", "
+			}
+			s += v.String()
+		}
+		s += " := "
+	}
+	for i, c := range p.Cmds {
+		if i > 0 {
+			s += " | "
+		}
+		s += c.String()
+	}
+	return s
+}
+
+func (p *PipeNode) tree() *Tree {
+	return p.tr
+}
+
+func (p *PipeNode) CopyPipe() *PipeNode {
+	if p == nil {
+		return p
+	}
+	var decl []*VariableNode
+	for _, d := range p.Decl {
+		decl = append(decl, d.Copy().(*VariableNode))
+	}
+	n := p.tr.newPipeline(p.Pos, p.Line, decl)
+	for _, c := range p.Cmds {
+		n.append(c.Copy().(*CommandNode))
+	}
+	return n
+}
+
+func (p *PipeNode) Copy() Node {
+	return p.CopyPipe()
+}
+
+// ActionNode holds an action (something bounded by delimiters).
+// Control actions have their own nodes; ActionNode represents simple
+// ones such as field evaluations and parenthesized pipelines.
+type ActionNode struct {
+	NodeType
+	Pos
+	tr   *Tree
+	Line int       // The line number in the input (deprecated; kept for compatibility)
+	Pipe *PipeNode // The pipeline in the action.
+}
+
+func (t *Tree) newAction(pos Pos, line int, pipe *PipeNode) *ActionNode {
+	return &ActionNode{tr: t, NodeType: NodeAction, Pos: pos, Line: line, Pipe: pipe}
+}
+
+func (a *ActionNode) String() string {
+	return fmt.Sprintf("{{%s}}", a.Pipe)
+
+}
+
+func (a *ActionNode) tree() *Tree {
+	return a.tr
+}
+
+func (a *ActionNode) Copy() Node {
+	return a.tr.newAction(a.Pos, a.Line, a.Pipe.CopyPipe())
+
+}
+
+// CommandNode holds a command (a pipeline inside an evaluating action).
+type CommandNode struct {
+	NodeType
+	Pos
+	tr   *Tree
+	Args []Node // Arguments in lexical order: Identifier, field, or constant.
+}
+
+func (t *Tree) newCommand(pos Pos) *CommandNode {
+	return &CommandNode{tr: t, NodeType: NodeCommand, Pos: pos}
+}
+
+func (c *CommandNode) append(arg Node) {
+	c.Args = append(c.Args, arg)
+}
+
+func (c *CommandNode) String() string {
+	s := ""
+	for i, arg := range c.Args {
+		if i > 0 {
+			s += " "
+		}
+		if arg, ok := arg.(*PipeNode); ok {
+			s += "(" + arg.String() + ")"
+			continue
+		}
+		s += arg.String()
+	}
+	return s
+}
+
+func (c *CommandNode) tree() *Tree {
+	return c.tr
+}
+
+func (c *CommandNode) Copy() Node {
+	if c == nil {
+		return c
+	}
+	n := c.tr.newCommand(c.Pos)
+	for _, c := range c.Args {
+		n.append(c.Copy())
+	}
+	return n
+}
+
+// IdentifierNode holds an identifier.
+type IdentifierNode struct {
+	NodeType
+	Pos
+	tr    *Tree
+	Ident string // The identifier's name.
+}
+
+// NewIdentifier returns a new IdentifierNode with the given identifier name.
+func NewIdentifier(ident string) *IdentifierNode {
+	return &IdentifierNode{NodeType: NodeIdentifier, Ident: ident}
+}
+
+// SetPos sets the position. NewIdentifier is a public method so we can't modify its signature.
+// Chained for convenience.
+// TODO: fix one day?
+func (i *IdentifierNode) SetPos(pos Pos) *IdentifierNode {
+	i.Pos = pos
+	return i
+}
+
+// SetTree sets the parent tree for the node. NewIdentifier is a public method so we can't modify its signature.
+// Chained for convenience.
+// TODO: fix one day?
+func (i *IdentifierNode) SetTree(t *Tree) *IdentifierNode {
+	i.tr = t
+	return i
+}
+
+func (i *IdentifierNode) String() string {
+	return i.Ident
+}
+
+func (i *IdentifierNode) tree() *Tree {
+	return i.tr
+}
+
+func (i *IdentifierNode) Copy() Node {
+	return NewIdentifier(i.Ident).SetTree(i.tr).SetPos(i.Pos)
+}
+
+// VariableNode holds a list of variable names, possibly with chained field
+// accesses. The dollar sign is part of the (first) name.
+type VariableNode struct {
+	NodeType
+	Pos
+	tr    *Tree
+	Ident []string // Variable name and fields in lexical order.
+}
+
+func (t *Tree) newVariable(pos Pos, ident string) *VariableNode {
+	return &VariableNode{tr: t, NodeType: NodeVariable, Pos: pos, Ident: strings.Split(ident, ".")}
+}
+
+func (v *VariableNode) String() string {
+	s := ""
+	for i, id := range v.Ident {
+		if i > 0 {
+			s += "."
+		}
+		s += id
+	}
+	return s
+}
+
+func (v *VariableNode) tree() *Tree {
+	return v.tr
+}
+
+func (v *VariableNode) Copy() Node {
+	return &VariableNode{tr: v.tr, NodeType: NodeVariable, Pos: v.Pos, Ident: append([]string{}, v.Ident...)}
+}
+
+// DotNode holds the special identifier '.'.
+type DotNode struct {
+	NodeType
+	Pos
+	tr *Tree
+}
+
+func (t *Tree) newDot(pos Pos) *DotNode {
+	return &DotNode{tr: t, NodeType: NodeDot, Pos: pos}
+}
+
+func (d *DotNode) Type() NodeType {
+	// Override method on embedded NodeType for API compatibility.
+	// TODO: Not really a problem; could change API without effect but
+	// api tool complains.
+	return NodeDot
+}
+
+func (d *DotNode) String() string {
+	return "."
+}
+
+func (d *DotNode) tree() *Tree {
+	return d.tr
+}
+
+func (d *DotNode) Copy() Node {
+	return d.tr.newDot(d.Pos)
+}
+
+// NilNode holds the special identifier 'nil' representing an untyped nil constant.
+type NilNode struct {
+	NodeType
+	Pos
+	tr *Tree
+}
+
+func (t *Tree) newNil(pos Pos) *NilNode {
+	return &NilNode{tr: t, NodeType: NodeNil, Pos: pos}
+}
+
+func (n *NilNode) Type() NodeType {
+	// Override method on embedded NodeType for API compatibility.
+	// TODO: Not really a problem; could change API without effect but
+	// api tool complains.
+	return NodeNil
+}
+
+func (n *NilNode) String() string {
+	return "nil"
+}
+
+func (n *NilNode) tree() *Tree {
+	return n.tr
+}
+
+func (n *NilNode) Copy() Node {
+	return n.tr.newNil(n.Pos)
+}
+
+// FieldNode holds a field (identifier starting with '.').
+// The names may be chained ('.x.y').
+// The period is dropped from each ident.
+type FieldNode struct {
+	NodeType
+	Pos
+	tr    *Tree
+	Ident []string // The identifiers in lexical order.
+}
+
+func (t *Tree) newField(pos Pos, ident string) *FieldNode {
+	return &FieldNode{tr: t, NodeType: NodeField, Pos: pos, Ident: strings.Split(ident[1:], ".")} // [1:] to drop leading period
+}
+
+func (f *FieldNode) String() string {
+	s := ""
+	for _, id := range f.Ident {
+		s += "." + id
+	}
+	return s
+}
+
+func (f *FieldNode) tree() *Tree {
+	return f.tr
+}
+
+func (f *FieldNode) Copy() Node {
+	return &FieldNode{tr: f.tr, NodeType: NodeField, Pos: f.Pos, Ident: append([]string{}, f.Ident...)}
+}
+
+// ChainNode holds a term followed by a chain of field accesses (identifier starting with '.').
+// The names may be chained ('.x.y').
+// The periods are dropped from each ident.
+type ChainNode struct {
+	NodeType
+	Pos
+	tr    *Tree
+	Node  Node
+	Field []string // The identifiers in lexical order.
+}
+
+func (t *Tree) newChain(pos Pos, node Node) *ChainNode {
+	return &ChainNode{tr: t, NodeType: NodeChain, Pos: pos, Node: node}
+}
+
+// Add adds the named field (which should start with a period) to the end of the chain.
+func (c *ChainNode) Add(field string) {
+	if len(field) == 0 || field[0] != '.' {
+		panic("no dot in field")
+	}
+	field = field[1:] // Remove leading dot.
+	if field == "" {
+		panic("empty field")
+	}
+	c.Field = append(c.Field, field)
+}
+
+func (c *ChainNode) String() string {
+	s := c.Node.String()
+	if _, ok := c.Node.(*PipeNode); ok {
+		s = "(" + s + ")"
+	}
+	for _, field := range c.Field {
+		s += "." + field
+	}
+	return s
+}
+
+func (c *ChainNode) tree() *Tree {
+	return c.tr
+}
+
+func (c *ChainNode) Copy() Node {
+	return &ChainNode{tr: c.tr, NodeType: NodeChain, Pos: c.Pos, Node: c.Node, Field: append([]string{}, c.Field...)}
+}
+
+// BoolNode holds a boolean constant.
+type BoolNode struct {
+	NodeType
+	Pos
+	tr   *Tree
+	True bool // The value of the boolean constant.
+}
+
+func (t *Tree) newBool(pos Pos, true bool) *BoolNode {
+	return &BoolNode{tr: t, NodeType: NodeBool, Pos: pos, True: true}
+}
+
+func (b *BoolNode) String() string {
+	if b.True {
+		return "true"
+	}
+	return "false"
+}
+
+func (b *BoolNode) tree() *Tree {
+	return b.tr
+}
+
+func (b *BoolNode) Copy() Node {
+	return b.tr.newBool(b.Pos, b.True)
+}
+
+// NumberNode holds a number: signed or unsigned integer, float, or complex.
+// The value is parsed and stored under all the types that can represent the value.
+// This simulates in a small amount of code the behavior of Go's ideal constants.
+type NumberNode struct {
+	NodeType
+	Pos
+	tr         *Tree
+	IsInt      bool       // Number has an integral value.
+	IsUint     bool       // Number has an unsigned integral value.
+	IsFloat    bool       // Number has a floating-point value.
+	IsComplex  bool       // Number is complex.
+	Int64      int64      // The signed integer value.
+	Uint64     uint64     // The unsigned integer value.
+	Float64    float64    // The floating-point value.
+	Complex128 complex128 // The complex value.
+	Text       string     // The original textual representation from the input.
+}
+
+func (t *Tree) newNumber(pos Pos, text string, typ itemType) (*NumberNode, error) {
+	n := &NumberNode{tr: t, NodeType: NodeNumber, Pos: pos, Text: text}
+	switch typ {
+	case itemCharConstant:
+		rune, _, tail, err := strconv.UnquoteChar(text[1:], text[0])
+		if err != nil {
+			return nil, err
+		}
+		if tail != "'" {
+			return nil, fmt.Errorf("malformed character constant: %s", text)
+		}
+		n.Int64 = int64(rune)
+		n.IsInt = true
+		n.Uint64 = uint64(rune)
+		n.IsUint = true
+		n.Float64 = float64(rune) // odd but those are the rules.
+		n.IsFloat = true
+		return n, nil
+	case itemComplex:
+		// fmt.Sscan can parse the pair, so let it do the work.
+		if _, err := fmt.Sscan(text, &n.Complex128); err != nil {
+			return nil, err
+		}
+		n.IsComplex = true
+		n.simplifyComplex()
+		return n, nil
+	}
+	// Imaginary constants can only be complex unless they are zero.
+	if len(text) > 0 && text[len(text)-1] == 'i' {
+		f, err := strconv.ParseFloat(text[:len(text)-1], 64)
+		if err == nil {
+			n.IsComplex = true
+			n.Complex128 = complex(0, f)
+			n.simplifyComplex()
+			return n, nil
+		}
+	}
+	// Do integer test first so we get 0x123 etc.
+	u, err := strconv.ParseUint(text, 0, 64) // will fail for -0; fixed below.
+	if err == nil {
+		n.IsUint = true
+		n.Uint64 = u
+	}
+	i, err := strconv.ParseInt(text, 0, 64)
+	if err == nil {
+		n.IsInt = true
+		n.Int64 = i
+		if i == 0 {
+			n.IsUint = true // in case of -0.
+			n.Uint64 = u
+		}
+	}
+	// If an integer extraction succeeded, promote the float.
+	if n.IsInt {
+		n.IsFloat = true
+		n.Float64 = float64(n.Int64)
+	} else if n.IsUint {
+		n.IsFloat = true
+		n.Float64 = float64(n.Uint64)
+	} else {
+		f, err := strconv.ParseFloat(text, 64)
+		if err == nil {
+			n.IsFloat = true
+			n.Float64 = f
+			// If a floating-point extraction succeeded, extract the int if needed.
+			if !n.IsInt && float64(int64(f)) == f {
+				n.IsInt = true
+				n.Int64 = int64(f)
+			}
+			if !n.IsUint && float64(uint64(f)) == f {
+				n.IsUint = true
+				n.Uint64 = uint64(f)
+			}
+		}
+	}
+	if !n.IsInt && !n.IsUint && !n.IsFloat {
+		return nil, fmt.Errorf("illegal number syntax: %q", text)
+	}
+	return n, nil
+}
+
+// simplifyComplex pulls out any other types that are represented by the complex number.
+// These all require that the imaginary part be zero.
+func (n *NumberNode) simplifyComplex() {
+	n.IsFloat = imag(n.Complex128) == 0
+	if n.IsFloat {
+		n.Float64 = real(n.Complex128)
+		n.IsInt = float64(int64(n.Float64)) == n.Float64
+		if n.IsInt {
+			n.Int64 = int64(n.Float64)
+		}
+		n.IsUint = float64(uint64(n.Float64)) == n.Float64
+		if n.IsUint {
+			n.Uint64 = uint64(n.Float64)
+		}
+	}
+}
+
+func (n *NumberNode) String() string {
+	return n.Text
+}
+
+func (n *NumberNode) tree() *Tree {
+	return n.tr
+}
+
+func (n *NumberNode) Copy() Node {
+	nn := new(NumberNode)
+	*nn = *n // Easy, fast, correct.
+	return nn
+}
+
+// StringNode holds a string constant. The value has been "unquoted".
+type StringNode struct {
+	NodeType
+	Pos
+	tr     *Tree
+	Quoted string // The original text of the string, with quotes.
+	Text   string // The string, after quote processing.
+}
+
+func (t *Tree) newString(pos Pos, orig, text string) *StringNode {
+	return &StringNode{tr: t, NodeType: NodeString, Pos: pos, Quoted: orig, Text: text}
+}
+
+func (s *StringNode) String() string {
+	return s.Quoted
+}
+
+func (s *StringNode) tree() *Tree {
+	return s.tr
+}
+
+func (s *StringNode) Copy() Node {
+	return s.tr.newString(s.Pos, s.Quoted, s.Text)
+}
+
+// endNode represents an {{end}} action.
+// It does not appear in the final parse tree.
+type endNode struct {
+	NodeType
+	Pos
+	tr *Tree
+}
+
+func (t *Tree) newEnd(pos Pos) *endNode {
+	return &endNode{tr: t, NodeType: nodeEnd, Pos: pos}
+}
+
+func (e *endNode) String() string {
+	return "{{end}}"
+}
+
+func (e *endNode) tree() *Tree {
+	return e.tr
+}
+
+func (e *endNode) Copy() Node {
+	return e.tr.newEnd(e.Pos)
+}
+
+// elseNode represents an {{else}} action. Does not appear in the final tree.
+type elseNode struct {
+	NodeType
+	Pos
+	tr   *Tree
+	Line int // The line number in the input (deprecated; kept for compatibility)
+}
+
+func (t *Tree) newElse(pos Pos, line int) *elseNode {
+	return &elseNode{tr: t, NodeType: nodeElse, Pos: pos, Line: line}
+}
+
+func (e *elseNode) Type() NodeType {
+	return nodeElse
+}
+
+func (e *elseNode) String() string {
+	return "{{else}}"
+}
+
+func (e *elseNode) tree() *Tree {
+	return e.tr
+}
+
+func (e *elseNode) Copy() Node {
+	return e.tr.newElse(e.Pos, e.Line)
+}
+
+// BranchNode is the common representation of if, range, and with.
+type BranchNode struct {
+	NodeType
+	Pos
+	tr       *Tree
+	Line     int       // The line number in the input (deprecated; kept for compatibility)
+	Pipe     *PipeNode // The pipeline to be evaluated.
+	List     *ListNode // What to execute if the value is non-empty.
+	ElseList *ListNode // What to execute if the value is empty (nil if absent).
+}
+
+func (b *BranchNode) String() string {
+	name := ""
+	switch b.NodeType {
+	case NodeIf:
+		name = "if"
+	case NodeRange:
+		name = "range"
+	case NodeWith:
+		name = "with"
+	default:
+		panic("unknown branch type")
+	}
+	if b.ElseList != nil {
+		return fmt.Sprintf("{{%s %s}}%s{{else}}%s{{end}}", name, b.Pipe, b.List, b.ElseList)
+	}
+	return fmt.Sprintf("{{%s %s}}%s{{end}}", name, b.Pipe, b.List)
+}
+
+func (b *BranchNode) tree() *Tree {
+	return b.tr
+}
+
+func (b *BranchNode) Copy() Node {
+	switch b.NodeType {
+	case NodeIf:
+		return b.tr.newIf(b.Pos, b.Line, b.Pipe, b.List, b.ElseList)
+	case NodeRange:
+		return b.tr.newRange(b.Pos, b.Line, b.Pipe, b.List, b.ElseList)
+	case NodeWith:
+		return b.tr.newWith(b.Pos, b.Line, b.Pipe, b.List, b.ElseList)
+	default:
+		panic("unknown branch type")
+	}
+}
+
+// IfNode represents an {{if}} action and its commands.
+type IfNode struct {
+	BranchNode
+}
+
+func (t *Tree) newIf(pos Pos, line int, pipe *PipeNode, list, elseList *ListNode) *IfNode {
+	return &IfNode{BranchNode{tr: t, NodeType: NodeIf, Pos: pos, Line: line, Pipe: pipe, List: list, ElseList: elseList}}
+}
+
+func (i *IfNode) Copy() Node {
+	return i.tr.newIf(i.Pos, i.Line, i.Pipe.CopyPipe(), i.List.CopyList(), i.ElseList.CopyList())
+}
+
+// RangeNode represents a {{range}} action and its commands.
+type RangeNode struct {
+	BranchNode
+}
+
+func (t *Tree) newRange(pos Pos, line int, pipe *PipeNode, list, elseList *ListNode) *RangeNode {
+	return &RangeNode{BranchNode{tr: t, NodeType: NodeRange, Pos: pos, Line: line, Pipe: pipe, List: list, ElseList: elseList}}
+}
+
+func (r *RangeNode) Copy() Node {
+	return r.tr.newRange(r.Pos, r.Line, r.Pipe.CopyPipe(), r.List.CopyList(), r.ElseList.CopyList())
+}
+
+// WithNode represents a {{with}} action and its commands.
+type WithNode struct {
+	BranchNode
+}
+
+func (t *Tree) newWith(pos Pos, line int, pipe *PipeNode, list, elseList *ListNode) *WithNode {
+	return &WithNode{BranchNode{tr: t, NodeType: NodeWith, Pos: pos, Line: line, Pipe: pipe, List: list, ElseList: elseList}}
+}
+
+func (w *WithNode) Copy() Node {
+	return w.tr.newWith(w.Pos, w.Line, w.Pipe.CopyPipe(), w.List.CopyList(), w.ElseList.CopyList())
+}
+
+// TemplateNode represents a {{template}} action.
+type TemplateNode struct {
+	NodeType
+	Pos
+	tr   *Tree
+	Line int       // The line number in the input (deprecated; kept for compatibility)
+	Name string    // The name of the template (unquoted).
+	Pipe *PipeNode // The command to evaluate as dot for the template.
+}
+
+func (t *Tree) newTemplate(pos Pos, line int, name string, pipe *PipeNode) *TemplateNode {
+	return &TemplateNode{tr: t, NodeType: NodeTemplate, Pos: pos, Line: line, Name: name, Pipe: pipe}
+}
+
+func (t *TemplateNode) String() string {
+	if t.Pipe == nil {
+		return fmt.Sprintf("{{template %q}}", t.Name)
+	}
+	return fmt.Sprintf("{{template %q %s}}", t.Name, t.Pipe)
+}
+
+func (t *TemplateNode) tree() *Tree {
+	return t.tr
+}
+
+func (t *TemplateNode) Copy() Node {
+	return t.tr.newTemplate(t.Pos, t.Line, t.Name, t.Pipe.CopyPipe())
+}

vendor/github.com/alecthomas/template/parse/parse.go

@@ -0,0 +1,700 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package parse builds parse trees for templates as defined by text/template
+// and html/template. Clients should use those packages to construct templates
+// rather than this one, which provides shared internal data structures not
+// intended for general use.
+package parse
+
+import (
+	"bytes"
+	"fmt"
+	"runtime"
+	"strconv"
+	"strings"
+)
+
+// Tree is the representation of a single parsed template.
+type Tree struct {
+	Name      string    // name of the template represented by the tree.
+	ParseName string    // name of the top-level template during parsing, for error messages.
+	Root      *ListNode // top-level root of the tree.
+	text      string    // text parsed to create the template (or its parent)
+	// Parsing only; cleared after parse.
+	funcs     []map[string]interface{}
+	lex       *lexer
+	token     [3]item // three-token lookahead for parser.
+	peekCount int
+	vars      []string // variables defined at the moment.
+}
+
+// Copy returns a copy of the Tree. Any parsing state is discarded.
+func (t *Tree) Copy() *Tree {
+	if t == nil {
+		return nil
+	}
+	return &Tree{
+		Name:      t.Name,
+		ParseName: t.ParseName,
+		Root:      t.Root.CopyList(),
+		text:      t.text,
+	}
+}
+
+// Parse returns a map from template name to parse.Tree, created by parsing the
+// templates described in the argument string. The top-level template will be
+// given the specified name. If an error is encountered, parsing stops and an
+// empty map is returned with the error.
+func Parse(name, text, leftDelim, rightDelim string, funcs ...map[string]interface{}) (treeSet map[string]*Tree, err error) {
+	treeSet = make(map[string]*Tree)
+	t := New(name)
+	t.text = text
+	_, err = t.Parse(text, leftDelim, rightDelim, treeSet, funcs...)
+	return
+}
+
+// next returns the next token.
+func (t *Tree) next() item {
+	if t.peekCount > 0 {
+		t.peekCount--
+	} else {
+		t.token[0] = t.lex.nextItem()
+	}
+	return t.token[t.peekCount]
+}
+
+// backup backs the input stream up one token.
+func (t *Tree) backup() {
+	t.peekCount++
+}
+
+// backup2 backs the input stream up two tokens.
+// The zeroth token is already there.
+func (t *Tree) backup2(t1 item) {
+	t.token[1] = t1
+	t.peekCount = 2
+}
+
+// backup3 backs the input stream up three tokens
+// The zeroth token is already there.
+func (t *Tree) backup3(t2, t1 item) { // Reverse order: we're pushing back.
+	t.token[1] = t1
+	t.token[2] = t2
+	t.peekCount = 3
+}
+
+// peek returns but does not consume the next token.
+func (t *Tree) peek() item {
+	if t.peekCount > 0 {
+		return t.token[t.peekCount-1]
+	}
+	t.peekCount = 1
+	t.token[0] = t.lex.nextItem()
+	return t.token[0]
+}
+
+// nextNonSpace returns the next non-space token.
+func (t *Tree) nextNonSpace() (token item) {
+	for {
+		token = t.next()
+		if token.typ != itemSpace {
+			break
+		}
+	}
+	return token
+}
+
+// peekNonSpace returns but does not consume the next non-space token.
+func (t *Tree) peekNonSpace() (token item) {
+	for {
+		token = t.next()
+		if token.typ != itemSpace {
+			break
+		}
+	}
+	t.backup()
+	return token
+}
+
+// Parsing.
+
+// New allocates a new parse tree with the given name.
+func New(name string, funcs ...map[string]interface{}) *Tree {
+	return &Tree{
+		Name:  name,
+		funcs: funcs,
+	}
+}
+
+// ErrorContext returns a textual representation of the location of the node in the input text.
+// The receiver is only used when the node does not have a pointer to the tree inside,
+// which can occur in old code.
+func (t *Tree) ErrorContext(n Node) (location, context string) {
+	pos := int(n.Position())
+	tree := n.tree()
+	if tree == nil {
+		tree = t
+	}
+	text := tree.text[:pos]
+	byteNum := strings.LastIndex(text, "\n")
+	if byteNum == -1 {
+		byteNum = pos // On first line.
+	} else {
+		byteNum++ // After the newline.
+		byteNum = pos - byteNum
+	}
+	lineNum := 1 + strings.Count(text, "\n")
+	context = n.String()
+	if len(context) > 20 {
+		context = fmt.Sprintf("%.20s...", context)
+	}
+	return fmt.Sprintf("%s:%d:%d", tree.ParseName, lineNum, byteNum), context
+}
+
+// errorf formats the error and terminates processing.
+func (t *Tree) errorf(format string, args ...interface{}) {
+	t.Root = nil
+	format = fmt.Sprintf("template: %s:%d: %s", t.ParseName, t.lex.lineNumber(), format)
+	panic(fmt.Errorf(format, args...))
+}
+
+// error terminates processing.
+func (t *Tree) error(err error) {
+	t.errorf("%s", err)
+}
+
+// expect consumes the next token and guarantees it has the required type.
+func (t *Tree) expect(expected itemType, context string) item {
+	token := t.nextNonSpace()
+	if token.typ != expected {
+		t.unexpected(token, context)
+	}
+	return token
+}
+
+// expectOneOf consumes the next token and guarantees it has one of the required types.
+func (t *Tree) expectOneOf(expected1, expected2 itemType, context string) item {
+	token := t.nextNonSpace()
+	if token.typ != expected1 && token.typ != expected2 {
+		t.unexpected(token, context)
+	}
+	return token
+}
+
+// unexpected complains about the token and terminates processing.
+func (t *Tree) unexpected(token item, context string) {
+	t.errorf("unexpected %s in %s", token, context)
+}
+
+// recover is the handler that turns panics into returns from the top level of Parse.
+func (t *Tree) recover(errp *error) {
+	e := recover()
+	if e != nil {
+		if _, ok := e.(runtime.Error); ok {
+			panic(e)
+		}
+		if t != nil {
+			t.stopParse()
+		}
+		*errp = e.(error)
+	}
+	return
+}
+
+// startParse initializes the parser, using the lexer.
+func (t *Tree) startParse(funcs []map[string]interface{}, lex *lexer) {
+	t.Root = nil
+	t.lex = lex
+	t.vars = []string{"$"}
+	t.funcs = funcs
+}
+
+// stopParse terminates parsing.
+func (t *Tree) stopParse() {
+	t.lex = nil
+	t.vars = nil
+	t.funcs = nil
+}
+
+// Parse parses the template definition string to construct a representation of
+// the template for execution. If either action delimiter string is empty, the
+// default ("{{" or "}}") is used. Embedded template definitions are added to
+// the treeSet map.
+func (t *Tree) Parse(text, leftDelim, rightDelim string, treeSet map[string]*Tree, funcs ...map[string]interface{}) (tree *Tree, err error) {
+	defer t.recover(&err)
+	t.ParseName = t.Name
+	t.startParse(funcs, lex(t.Name, text, leftDelim, rightDelim))
+	t.text = text
+	t.parse(treeSet)
+	t.add(treeSet)
+	t.stopParse()
+	return t, nil
+}
+
+// add adds tree to the treeSet.
+func (t *Tree) add(treeSet map[string]*Tree) {
+	tree := treeSet[t.Name]
+	if tree == nil || IsEmptyTree(tree.Root) {
+		treeSet[t.Name] = t
+		return
+	}
+	if !IsEmptyTree(t.Root) {
+		t.errorf("template: multiple definition of template %q", t.Name)
+	}
+}
+
+// IsEmptyTree reports whether this tree (node) is empty of everything but space.
+func IsEmptyTree(n Node) bool {
+	switch n := n.(type) {
+	case nil:
+		return true
+	case *ActionNode:
+	case *IfNode:
+	case *ListNode:
+		for _, node := range n.Nodes {
+			if !IsEmptyTree(node) {
+				return false
+			}
+		}
+		return true
+	case *RangeNode:
+	case *TemplateNode:
+	case *TextNode:
+		return len(bytes.TrimSpace(n.Text)) == 0
+	case *WithNode:
+	default:
+		panic("unknown node: " + n.String())
+	}
+	return false
+}
+
+// parse is the top-level parser for a template, essentially the same
+// as itemList except it also parses {{define}} actions.
+// It runs to EOF.
+func (t *Tree) parse(treeSet map[string]*Tree) (next Node) {
+	t.Root = t.newList(t.peek().pos)
+	for t.peek().typ != itemEOF {
+		if t.peek().typ == itemLeftDelim {
+			delim := t.next()
+			if t.nextNonSpace().typ == itemDefine {
+				newT := New("definition") // name will be updated once we know it.
+				newT.text = t.text
+				newT.ParseName = t.ParseName
+				newT.startParse(t.funcs, t.lex)
+				newT.parseDefinition(treeSet)
+				continue
+			}
+			t.backup2(delim)
+		}
+		n := t.textOrAction()
+		if n.Type() == nodeEnd {
+			t.errorf("unexpected %s", n)
+		}
+		t.Root.append(n)
+	}
+	return nil
+}
+
+// parseDefinition parses a {{define}} ...  {{end}} template definition and
+// installs the definition in the treeSet map.  The "define" keyword has already
+// been scanned.
+func (t *Tree) parseDefinition(treeSet map[string]*Tree) {
+	const context = "define clause"
+	name := t.expectOneOf(itemString, itemRawString, context)
+	var err error
+	t.Name, err = strconv.Unquote(name.val)
+	if err != nil {
+		t.error(err)
+	}
+	t.expect(itemRightDelim, context)
+	var end Node
+	t.Root, end = t.itemList()
+	if end.Type() != nodeEnd {
+		t.errorf("unexpected %s in %s", end, context)
+	}
+	t.add(treeSet)
+	t.stopParse()
+}
+
+// itemList:
+//	textOrAction*
+// Terminates at {{end}} or {{else}}, returned separately.
+func (t *Tree) itemList() (list *ListNode, next Node) {
+	list = t.newList(t.peekNonSpace().pos)
+	for t.peekNonSpace().typ != itemEOF {
+		n := t.textOrAction()
+		switch n.Type() {
+		case nodeEnd, nodeElse:
+			return list, n
+		}
+		list.append(n)
+	}
+	t.errorf("unexpected EOF")
+	return
+}
+
+// textOrAction:
+//	text | action
+func (t *Tree) textOrAction() Node {
+	switch token := t.nextNonSpace(); token.typ {
+	case itemElideNewline:
+		return t.elideNewline()
+	case itemText:
+		return t.newText(token.pos, token.val)
+	case itemLeftDelim:
+		return t.action()
+	default:
+		t.unexpected(token, "input")
+	}
+	return nil
+}
+
+// elideNewline:
+// Remove newlines trailing rightDelim if \\ is present.
+func (t *Tree) elideNewline() Node {
+	token := t.peek()
+	if token.typ != itemText {
+		t.unexpected(token, "input")
+		return nil
+	}
+
+	t.next()
+	stripped := strings.TrimLeft(token.val, "\n\r")
+	diff := len(token.val) - len(stripped)
+	if diff > 0 {
+		// This is a bit nasty. We mutate the token in-place to remove
+		// preceding newlines.
+		token.pos += Pos(diff)
+		token.val = stripped
+	}
+	return t.newText(token.pos, token.val)
+}
+
+// Action:
+//	control
+//	command ("|" command)*
+// Left delim is past. Now get actions.
+// First word could be a keyword such as range.
+func (t *Tree) action() (n Node) {
+	switch token := t.nextNonSpace(); token.typ {
+	case itemElse:
+		return t.elseControl()
+	case itemEnd:
+		return t.endControl()
+	case itemIf:
+		return t.ifControl()
+	case itemRange:
+		return t.rangeControl()
+	case itemTemplate:
+		return t.templateControl()
+	case itemWith:
+		return t.withControl()
+	}
+	t.backup()
+	// Do not pop variables; they persist until "end".
+	return t.newAction(t.peek().pos, t.lex.lineNumber(), t.pipeline("command"))
+}
+
+// Pipeline:
+//	declarations? command ('|' command)*
+func (t *Tree) pipeline(context string) (pipe *PipeNode) {
+	var decl []*VariableNode
+	pos := t.peekNonSpace().pos
+	// Are there declarations?
+	for {
+		if v := t.peekNonSpace(); v.typ == itemVariable {
+			t.next()
+			// Since space is a token, we need 3-token look-ahead here in the worst case:
+			// in "$x foo" we need to read "foo" (as opposed to ":=") to know that $x is an
+			// argument variable rather than a declaration. So remember the token
+			// adjacent to the variable so we can push it back if necessary.
+			tokenAfterVariable := t.peek()
+			if next := t.peekNonSpace(); next.typ == itemColonEquals || (next.typ == itemChar && next.val == ",") {
+				t.nextNonSpace()
+				variable := t.newVariable(v.pos, v.val)
+				decl = append(decl, variable)
+				t.vars = append(t.vars, v.val)
+				if next.typ == itemChar && next.val == "," {
+					if context == "range" && len(decl) < 2 {
+						continue
+					}
+					t.errorf("too many declarations in %s", context)
+				}
+			} else if tokenAfterVariable.typ == itemSpace {
+				t.backup3(v, tokenAfterVariable)
+			} else {
+				t.backup2(v)
+			}
+		}
+		break
+	}
+	pipe = t.newPipeline(pos, t.lex.lineNumber(), decl)
+	for {
+		switch token := t.nextNonSpace(); token.typ {
+		case itemRightDelim, itemRightParen:
+			if len(pipe.Cmds) == 0 {
+				t.errorf("missing value for %s", context)
+			}
+			if token.typ == itemRightParen {
+				t.backup()
+			}
+			return
+		case itemBool, itemCharConstant, itemComplex, itemDot, itemField, itemIdentifier,
+			itemNumber, itemNil, itemRawString, itemString, itemVariable, itemLeftParen:
+			t.backup()
+			pipe.append(t.command())
+		default:
+			t.unexpected(token, context)
+		}
+	}
+}
+
+func (t *Tree) parseControl(allowElseIf bool, context string) (pos Pos, line int, pipe *PipeNode, list, elseList *ListNode) {
+	defer t.popVars(len(t.vars))
+	line = t.lex.lineNumber()
+	pipe = t.pipeline(context)
+	var next Node
+	list, next = t.itemList()
+	switch next.Type() {
+	case nodeEnd: //done
+	case nodeElse:
+		if allowElseIf {
+			// Special case for "else if". If the "else" is followed immediately by an "if",
+			// the elseControl will have left the "if" token pending. Treat
+			//	{{if a}}_{{else if b}}_{{end}}
+			// as
+			//	{{if a}}_{{else}}{{if b}}_{{end}}{{end}}.
+			// To do this, parse the if as usual and stop at it {{end}}; the subsequent{{end}}
+			// is assumed. This technique works even for long if-else-if chains.
+			// TODO: Should we allow else-if in with and range?
+			if t.peek().typ == itemIf {
+				t.next() // Consume the "if" token.
+				elseList = t.newList(next.Position())
+				elseList.append(t.ifControl())
+				// Do not consume the next item - only one {{end}} required.
+				break
+			}
+		}
+		elseList, next = t.itemList()
+		if next.Type() != nodeEnd {
+			t.errorf("expected end; found %s", next)
+		}
+	}
+	return pipe.Position(), line, pipe, list, elseList
+}
+
+// If:
+//	{{if pipeline}} itemList {{end}}
+//	{{if pipeline}} itemList {{else}} itemList {{end}}
+// If keyword is past.
+func (t *Tree) ifControl() Node {
+	return t.newIf(t.parseControl(true, "if"))
+}
+
+// Range:
+//	{{range pipeline}} itemList {{end}}
+//	{{range pipeline}} itemList {{else}} itemList {{end}}
+// Range keyword is past.
+func (t *Tree) rangeControl() Node {
+	return t.newRange(t.parseControl(false, "range"))
+}
+
+// With:
+//	{{with pipeline}} itemList {{end}}
+//	{{with pipeline}} itemList {{else}} itemList {{end}}
+// If keyword is past.
+func (t *Tree) withControl() Node {
+	return t.newWith(t.parseControl(false, "with"))
+}
+
+// End:
+//	{{end}}
+// End keyword is past.
+func (t *Tree) endControl() Node {
+	return t.newEnd(t.expect(itemRightDelim, "end").pos)
+}
+
+// Else:
+//	{{else}}
+// Else keyword is past.
+func (t *Tree) elseControl() Node {
+	// Special case for "else if".
+	peek := t.peekNonSpace()
+	if peek.typ == itemIf {
+		// We see "{{else if ... " but in effect rewrite it to {{else}}{{if ... ".
+		return t.newElse(peek.pos, t.lex.lineNumber())
+	}
+	return t.newElse(t.expect(itemRightDelim, "else").pos, t.lex.lineNumber())
+}
+
+// Template:
+//	{{template stringValue pipeline}}
+// Template keyword is past.  The name must be something that can evaluate
+// to a string.
+func (t *Tree) templateControl() Node {
+	var name string
+	token := t.nextNonSpace()
+	switch token.typ {
+	case itemString, itemRawString:
+		s, err := strconv.Unquote(token.val)
+		if err != nil {
+			t.error(err)
+		}
+		name = s
+	default:
+		t.unexpected(token, "template invocation")
+	}
+	var pipe *PipeNode
+	if t.nextNonSpace().typ != itemRightDelim {
+		t.backup()
+		// Do not pop variables; they persist until "end".
+		pipe = t.pipeline("template")
+	}
+	return t.newTemplate(token.pos, t.lex.lineNumber(), name, pipe)
+}
+
+// command:
+//	operand (space operand)*
+// space-separated arguments up to a pipeline character or right delimiter.
+// we consume the pipe character but leave the right delim to terminate the action.
+func (t *Tree) command() *CommandNode {
+	cmd := t.newCommand(t.peekNonSpace().pos)
+	for {
+		t.peekNonSpace() // skip leading spaces.
+		operand := t.operand()
+		if operand != nil {
+			cmd.append(operand)
+		}
+		switch token := t.next(); token.typ {
+		case itemSpace:
+			continue
+		case itemError:
+			t.errorf("%s", token.val)
+		case itemRightDelim, itemRightParen:
+			t.backup()
+		case itemPipe:
+		default:
+			t.errorf("unexpected %s in operand; missing space?", token)
+		}
+		break
+	}
+	if len(cmd.Args) == 0 {
+		t.errorf("empty command")
+	}
+	return cmd
+}
+
+// operand:
+//	term .Field*
+// An operand is a space-separated component of a command,
+// a term possibly followed by field accesses.
+// A nil return means the next item is not an operand.
+func (t *Tree) operand() Node {
+	node := t.term()
+	if node == nil {
+		return nil
+	}
+	if t.peek().typ == itemField {
+		chain := t.newChain(t.peek().pos, node)
+		for t.peek().typ == itemField {
+			chain.Add(t.next().val)
+		}
+		// Compatibility with original API: If the term is of type NodeField
+		// or NodeVariable, just put more fields on the original.
+		// Otherwise, keep the Chain node.
+		// TODO: Switch to Chains always when we can.
+		switch node.Type() {
+		case NodeField:
+			node = t.newField(chain.Position(), chain.String())
+		case NodeVariable:
+			node = t.newVariable(chain.Position(), chain.String())
+		default:
+			node = chain
+		}
+	}
+	return node
+}
+
+// term:
+//	literal (number, string, nil, boolean)
+//	function (identifier)
+//	.
+//	.Field
+//	$
+//	'(' pipeline ')'
+// A term is a simple "expression".
+// A nil return means the next item is not a term.
+func (t *Tree) term() Node {
+	switch token := t.nextNonSpace(); token.typ {
+	case itemError:
+		t.errorf("%s", token.val)
+	case itemIdentifier:
+		if !t.hasFunction(token.val) {
+			t.errorf("function %q not defined", token.val)
+		}
+		return NewIdentifier(token.val).SetTree(t).SetPos(token.pos)
+	case itemDot:
+		return t.newDot(token.pos)
+	case itemNil:
+		return t.newNil(token.pos)
+	case itemVariable:
+		return t.useVar(token.pos, token.val)
+	case itemField:
+		return t.newField(token.pos, token.val)
+	case itemBool:
+		return t.newBool(token.pos, token.val == "true")
+	case itemCharConstant, itemComplex, itemNumber:
+		number, err := t.newNumber(token.pos, token.val, token.typ)
+		if err != nil {
+			t.error(err)
+		}
+		return number
+	case itemLeftParen:
+		pipe := t.pipeline("parenthesized pipeline")
+		if token := t.next(); token.typ != itemRightParen {
+			t.errorf("unclosed right paren: unexpected %s", token)
+		}
+		return pipe
+	case itemString, itemRawString:
+		s, err := strconv.Unquote(token.val)
+		if err != nil {
+			t.error(err)
+		}
+		return t.newString(token.pos, token.val, s)
+	}
+	t.backup()
+	return nil
+}
+
+// hasFunction reports if a function name exists in the Tree's maps.
+func (t *Tree) hasFunction(name string) bool {
+	for _, funcMap := range t.funcs {
+		if funcMap == nil {
+			continue
+		}
+		if funcMap[name] != nil {
+			return true
+		}
+	}
+	return false
+}
+
+// popVars trims the variable list to the specified length
+func (t *Tree) popVars(n int) {
+	t.vars = t.vars[:n]
+}
+
+// useVar returns a node for a variable reference. It errors if the
+// variable is not defined.
+func (t *Tree) useVar(pos Pos, name string) Node {
+	v := t.newVariable(pos, name)
+	for _, varName := range t.vars {
+		if varName == v.Ident[0] {
+			return v
+		}
+	}
+	t.errorf("undefined variable %q", v.Ident[0])
+	return nil
+}

vendor/github.com/alecthomas/template/template.go

@@ -0,0 +1,218 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package template
+
+import (
+	"fmt"
+	"reflect"
+
+	"github.com/alecthomas/template/parse"
+)
+
+// common holds the information shared by related templates.
+type common struct {
+	tmpl map[string]*Template
+	// We use two maps, one for parsing and one for execution.
+	// This separation makes the API cleaner since it doesn't
+	// expose reflection to the client.
+	parseFuncs FuncMap
+	execFuncs  map[string]reflect.Value
+}
+
+// Template is the representation of a parsed template. The *parse.Tree
+// field is exported only for use by html/template and should be treated
+// as unexported by all other clients.
+type Template struct {
+	name string
+	*parse.Tree
+	*common
+	leftDelim  string
+	rightDelim string
+}
+
+// New allocates a new template with the given name.
+func New(name string) *Template {
+	return &Template{
+		name: name,
+	}
+}
+
+// Name returns the name of the template.
+func (t *Template) Name() string {
+	return t.name
+}
+
+// New allocates a new template associated with the given one and with the same
+// delimiters. The association, which is transitive, allows one template to
+// invoke another with a {{template}} action.
+func (t *Template) New(name string) *Template {
+	t.init()
+	return &Template{
+		name:       name,
+		common:     t.common,
+		leftDelim:  t.leftDelim,
+		rightDelim: t.rightDelim,
+	}
+}
+
+func (t *Template) init() {
+	if t.common == nil {
+		t.common = new(common)
+		t.tmpl = make(map[string]*Template)
+		t.parseFuncs = make(FuncMap)
+		t.execFuncs = make(map[string]reflect.Value)
+	}
+}
+
+// Clone returns a duplicate of the template, including all associated
+// templates. The actual representation is not copied, but the name space of
+// associated templates is, so further calls to Parse in the copy will add
+// templates to the copy but not to the original. Clone can be used to prepare
+// common templates and use them with variant definitions for other templates
+// by adding the variants after the clone is made.
+func (t *Template) Clone() (*Template, error) {
+	nt := t.copy(nil)
+	nt.init()
+	nt.tmpl[t.name] = nt
+	for k, v := range t.tmpl {
+		if k == t.name { // Already installed.
+			continue
+		}
+		// The associated templates share nt's common structure.
+		tmpl := v.copy(nt.common)
+		nt.tmpl[k] = tmpl
+	}
+	for k, v := range t.parseFuncs {
+		nt.parseFuncs[k] = v
+	}
+	for k, v := range t.execFuncs {
+		nt.execFuncs[k] = v
+	}
+	return nt, nil
+}
+
+// copy returns a shallow copy of t, with common set to the argument.
+func (t *Template) copy(c *common) *Template {
+	nt := New(t.name)
+	nt.Tree = t.Tree
+	nt.common = c
+	nt.leftDelim = t.leftDelim
+	nt.rightDelim = t.rightDelim
+	return nt
+}
+
+// AddParseTree creates a new template with the name and parse tree
+// and associates it with t.
+func (t *Template) AddParseTree(name string, tree *parse.Tree) (*Template, error) {
+	if t.common != nil && t.tmpl[name] != nil {
+		return nil, fmt.Errorf("template: redefinition of template %q", name)
+	}
+	nt := t.New(name)
+	nt.Tree = tree
+	t.tmpl[name] = nt
+	return nt, nil
+}
+
+// Templates returns a slice of the templates associated with t, including t
+// itself.
+func (t *Template) Templates() []*Template {
+	if t.common == nil {
+		return nil
+	}
+	// Return a slice so we don't expose the map.
+	m := make([]*Template, 0, len(t.tmpl))
+	for _, v := range t.tmpl {
+		m = append(m, v)
+	}
+	return m
+}
+
+// Delims sets the action delimiters to the specified strings, to be used in
+// subsequent calls to Parse, ParseFiles, or ParseGlob. Nested template
+// definitions will inherit the settings. An empty delimiter stands for the
+// corresponding default: {{ or }}.
+// The return value is the template, so calls can be chained.
+func (t *Template) Delims(left, right string) *Template {
+	t.leftDelim = left
+	t.rightDelim = right
+	return t
+}
+
+// Funcs adds the elements of the argument map to the template's function map.
+// It panics if a value in the map is not a function with appropriate return
+// type. However, it is legal to overwrite elements of the map. The return
+// value is the template, so calls can be chained.
+func (t *Template) Funcs(funcMap FuncMap) *Template {
+	t.init()
+	addValueFuncs(t.execFuncs, funcMap)
+	addFuncs(t.parseFuncs, funcMap)
+	return t
+}
+
+// Lookup returns the template with the given name that is associated with t,
+// or nil if there is no such template.
+func (t *Template) Lookup(name string) *Template {
+	if t.common == nil {
+		return nil
+	}
+	return t.tmpl[name]
+}
+
+// Parse parses a string into a template. Nested template definitions will be
+// associated with the top-level template t. Parse may be called multiple times
+// to parse definitions of templates to associate with t. It is an error if a
+// resulting template is non-empty (contains content other than template
+// definitions) and would replace a non-empty template with the same name.
+// (In multiple calls to Parse with the same receiver template, only one call
+// can contain text other than space, comments, and template definitions.)
+func (t *Template) Parse(text string) (*Template, error) {
+	t.init()
+	trees, err := parse.Parse(t.name, text, t.leftDelim, t.rightDelim, t.parseFuncs, builtins)
+	if err != nil {
+		return nil, err
+	}
+	// Add the newly parsed trees, including the one for t, into our common structure.
+	for name, tree := range trees {
+		// If the name we parsed is the name of this template, overwrite this template.
+		// The associate method checks it's not a redefinition.
+		tmpl := t
+		if name != t.name {
+			tmpl = t.New(name)
+		}
+		// Even if t == tmpl, we need to install it in the common.tmpl map.
+		if replace, err := t.associate(tmpl, tree); err != nil {
+			return nil, err
+		} else if replace {
+			tmpl.Tree = tree
+		}
+		tmpl.leftDelim = t.leftDelim
+		tmpl.rightDelim = t.rightDelim
+	}
+	return t, nil
+}
+
+// associate installs the new template into the group of templates associated
+// with t. It is an error to reuse a name except to overwrite an empty
+// template. The two are already known to share the common structure.
+// The boolean return value reports wither to store this tree as t.Tree.
+func (t *Template) associate(new *Template, tree *parse.Tree) (bool, error) {
+	if new.common != t.common {
+		panic("internal error: associate not common")
+	}
+	name := new.name
+	if old := t.tmpl[name]; old != nil {
+		oldIsEmpty := parse.IsEmptyTree(old.Root)
+		newIsEmpty := parse.IsEmptyTree(tree.Root)
+		if newIsEmpty {
+			// Whether old is empty or not, new is empty; no reason to replace old.
+			return false, nil
+		}
+		if !oldIsEmpty {
+			return false, fmt.Errorf("template: redefinition of template %q", name)
+		}
+	}
+	t.tmpl[name] = new
+	return true, nil
+}

vendor/github.com/alecthomas/units/COPYING

@@ -0,0 +1,19 @@
+Copyright (C) 2014 Alec Thomas
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/alecthomas/units/README.md

@@ -0,0 +1,11 @@
+# Units - Helpful unit multipliers and functions for Go
+
+The goal of this package is to have functionality similar to the [time](http://golang.org/pkg/time/) package.
+
+It allows for code like this:
+
+```go
+n, err := ParseBase2Bytes("1KB")
+// n == 1024
+n = units.Mebibyte * 512
+```

vendor/github.com/alecthomas/units/bytes.go

@@ -0,0 +1,83 @@
+package units
+
+// Base2Bytes is the old non-SI power-of-2 byte scale (1024 bytes in a kilobyte,
+// etc.).
+type Base2Bytes int64
+
+// Base-2 byte units.
+const (
+	Kibibyte Base2Bytes = 1024
+	KiB                 = Kibibyte
+	Mebibyte            = Kibibyte * 1024
+	MiB                 = Mebibyte
+	Gibibyte            = Mebibyte * 1024
+	GiB                 = Gibibyte
+	Tebibyte            = Gibibyte * 1024
+	TiB                 = Tebibyte
+	Pebibyte            = Tebibyte * 1024
+	PiB                 = Pebibyte
+	Exbibyte            = Pebibyte * 1024
+	EiB                 = Exbibyte
+)
+
+var (
+	bytesUnitMap    = MakeUnitMap("iB", "B", 1024)
+	oldBytesUnitMap = MakeUnitMap("B", "B", 1024)
+)
+
+// ParseBase2Bytes supports both iB and B in base-2 multipliers. That is, KB
+// and KiB are both 1024.
+func ParseBase2Bytes(s string) (Base2Bytes, error) {
+	n, err := ParseUnit(s, bytesUnitMap)
+	if err != nil {
+		n, err = ParseUnit(s, oldBytesUnitMap)
+	}
+	return Base2Bytes(n), err
+}
+
+func (b Base2Bytes) String() string {
+	return ToString(int64(b), 1024, "iB", "B")
+}
+
+var (
+	metricBytesUnitMap = MakeUnitMap("B", "B", 1000)
+)
+
+// MetricBytes are SI byte units (1000 bytes in a kilobyte).
+type MetricBytes SI
+
+// SI base-10 byte units.
+const (
+	Kilobyte MetricBytes = 1000
+	KB                   = Kilobyte
+	Megabyte             = Kilobyte * 1000
+	MB                   = Megabyte
+	Gigabyte             = Megabyte * 1000
+	GB                   = Gigabyte
+	Terabyte             = Gigabyte * 1000
+	TB                   = Terabyte
+	Petabyte             = Terabyte * 1000
+	PB                   = Petabyte
+	Exabyte              = Petabyte * 1000
+	EB                   = Exabyte
+)
+
+// ParseMetricBytes parses base-10 metric byte units. That is, KB is 1000 bytes.
+func ParseMetricBytes(s string) (MetricBytes, error) {
+	n, err := ParseUnit(s, metricBytesUnitMap)
+	return MetricBytes(n), err
+}
+
+func (m MetricBytes) String() string {
+	return ToString(int64(m), 1000, "B", "B")
+}
+
+// ParseStrictBytes supports both iB and B suffixes for base 2 and metric,
+// respectively. That is, KiB represents 1024 and KB represents 1000.
+func ParseStrictBytes(s string) (int64, error) {
+	n, err := ParseUnit(s, bytesUnitMap)
+	if err != nil {
+		n, err = ParseUnit(s, metricBytesUnitMap)
+	}
+	return int64(n), err
+}

vendor/github.com/alecthomas/units/doc.go

@@ -0,0 +1,13 @@
+// Package units provides helpful unit multipliers and functions for Go.
+//
+// The goal of this package is to have functionality similar to the time [1] package.
+//
+//
+// [1] http://golang.org/pkg/time/
+//
+// It allows for code like this:
+//
+//     n, err := ParseBase2Bytes("1KB")
+//     // n == 1024
+//     n = units.Mebibyte * 512
+package units

vendor/github.com/alecthomas/units/si.go

@@ -0,0 +1,26 @@
+package units
+
+// SI units.
+type SI int64
+
+// SI unit multiples.
+const (
+	Kilo SI = 1000
+	Mega    = Kilo * 1000
+	Giga    = Mega * 1000
+	Tera    = Giga * 1000
+	Peta    = Tera * 1000
+	Exa     = Peta * 1000
+)
+
+func MakeUnitMap(suffix, shortSuffix string, scale int64) map[string]float64 {
+	return map[string]float64{
+		shortSuffix:  1,
+		"K" + suffix: float64(scale),
+		"M" + suffix: float64(scale * scale),
+		"G" + suffix: float64(scale * scale * scale),
+		"T" + suffix: float64(scale * scale * scale * scale),
+		"P" + suffix: float64(scale * scale * scale * scale * scale),
+		"E" + suffix: float64(scale * scale * scale * scale * scale * scale),
+	}
+}

vendor/github.com/alecthomas/units/util.go

@@ -0,0 +1,138 @@
+package units
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+var (
+	siUnits = []string{"", "K", "M", "G", "T", "P", "E"}
+)
+
+func ToString(n int64, scale int64, suffix, baseSuffix string) string {
+	mn := len(siUnits)
+	out := make([]string, mn)
+	for i, m := range siUnits {
+		if n%scale != 0 || i == 0 && n == 0 {
+			s := suffix
+			if i == 0 {
+				s = baseSuffix
+			}
+			out[mn-1-i] = fmt.Sprintf("%d%s%s", n%scale, m, s)
+		}
+		n /= scale
+		if n == 0 {
+			break
+		}
+	}
+	return strings.Join(out, "")
+}
+
+// Below code ripped straight from http://golang.org/src/pkg/time/format.go?s=33392:33438#L1123
+var errLeadingInt = errors.New("units: bad [0-9]*") // never printed
+
+// leadingInt consumes the leading [0-9]* from s.
+func leadingInt(s string) (x int64, rem string, err error) {
+	i := 0
+	for ; i < len(s); i++ {
+		c := s[i]
+		if c < '0' || c > '9' {
+			break
+		}
+		if x >= (1<<63-10)/10 {
+			// overflow
+			return 0, "", errLeadingInt
+		}
+		x = x*10 + int64(c) - '0'
+	}
+	return x, s[i:], nil
+}
+
+func ParseUnit(s string, unitMap map[string]float64) (int64, error) {
+	// [-+]?([0-9]*(\.[0-9]*)?[a-z]+)+
+	orig := s
+	f := float64(0)
+	neg := false
+
+	// Consume [-+]?
+	if s != "" {
+		c := s[0]
+		if c == '-' || c == '+' {
+			neg = c == '-'
+			s = s[1:]
+		}
+	}
+	// Special case: if all that is left is "0", this is zero.
+	if s == "0" {
+		return 0, nil
+	}
+	if s == "" {
+		return 0, errors.New("units: invalid " + orig)
+	}
+	for s != "" {
+		g := float64(0) // this element of the sequence
+
+		var x int64
+		var err error
+
+		// The next character must be [0-9.]
+		if !(s[0] == '.' || ('0' <= s[0] && s[0] <= '9')) {
+			return 0, errors.New("units: invalid " + orig)
+		}
+		// Consume [0-9]*
+		pl := len(s)
+		x, s, err = leadingInt(s)
+		if err != nil {
+			return 0, errors.New("units: invalid " + orig)
+		}
+		g = float64(x)
+		pre := pl != len(s) // whether we consumed anything before a period
+
+		// Consume (\.[0-9]*)?
+		post := false
+		if s != "" && s[0] == '.' {
+			s = s[1:]
+			pl := len(s)
+			x, s, err = leadingInt(s)
+			if err != nil {
+				return 0, errors.New("units: invalid " + orig)
+			}
+			scale := 1.0
+			for n := pl - len(s); n > 0; n-- {
+				scale *= 10
+			}
+			g += float64(x) / scale
+			post = pl != len(s)
+		}
+		if !pre && !post {
+			// no digits (e.g. ".s" or "-.s")
+			return 0, errors.New("units: invalid " + orig)
+		}
+
+		// Consume unit.
+		i := 0
+		for ; i < len(s); i++ {
+			c := s[i]
+			if c == '.' || ('0' <= c && c <= '9') {
+				break
+			}
+		}
+		u := s[:i]
+		s = s[i:]
+		unit, ok := unitMap[u]
+		if !ok {
+			return 0, errors.New("units: unknown unit " + u + " in " + orig)
+		}
+
+		f += g * unit
+	}
+
+	if neg {
+		f = -f
+	}
+	if f < float64(-1<<63) || f > float64(1<<63-1) {
+		return 0, errors.New("units: overflow parsing unit")
+	}
+	return int64(f), nil
+}

vendor/github.com/golang/snappy/AUTHORS

@@ -0,0 +1,15 @@
+# This is the official list of Snappy-Go authors for copyright purposes.
+# This file is distinct from the CONTRIBUTORS files.
+# See the latter for an explanation.
+
+# Names should be added to this file as
+#	Name or Organization <email address>
+# The email address is not required for organizations.
+
+# Please keep the list sorted.
+
+Damian Gryski <dgryski@gmail.com>
+Google Inc.
+Jan Mercl <0xjnml@gmail.com>
+Rodolfo Carvalho <rhcarvalho@gmail.com>
+Sebastien Binet <seb.binet@gmail.com>

vendor/github.com/golang/snappy/CONTRIBUTORS

@@ -0,0 +1,37 @@
+# This is the official list of people who can contribute
+# (and typically have contributed) code to the Snappy-Go repository.
+# The AUTHORS file lists the copyright holders; this file
+# lists people.  For example, Google employees are listed here
+# but not in AUTHORS, because Google holds the copyright.
+#
+# The submission process automatically checks to make sure
+# that people submitting code are listed in this file (by email address).
+#
+# Names should be added to this file only after verifying that
+# the individual or the individual's organization has agreed to
+# the appropriate Contributor License Agreement, found here:
+#
+#     http://code.google.com/legal/individual-cla-v1.0.html
+#     http://code.google.com/legal/corporate-cla-v1.0.html
+#
+# The agreement for individuals can be filled out on the web.
+#
+# When adding J Random Contributor's name to this file,
+# either J's name or J's organization's name should be
+# added to the AUTHORS file, depending on whether the
+# individual or corporate CLA was used.
+
+# Names should be added to this file like so:
+#     Name <email address>
+
+# Please keep the list sorted.
+
+Damian Gryski <dgryski@gmail.com>
+Jan Mercl <0xjnml@gmail.com>
+Kai Backman <kaib@golang.org>
+Marc-Antoine Ruel <maruel@chromium.org>
+Nigel Tao <nigeltao@golang.org>
+Rob Pike <r@golang.org>
+Rodolfo Carvalho <rhcarvalho@gmail.com>
+Russ Cox <rsc@golang.org>
+Sebastien Binet <seb.binet@gmail.com>

vendor/github.com/golang/snappy/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2011 The Snappy-Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/golang/snappy/README

@@ -0,0 +1,107 @@
+The Snappy compression format in the Go programming language.
+
+To download and install from source:
+$ go get github.com/golang/snappy
+
+Unless otherwise noted, the Snappy-Go source files are distributed
+under the BSD-style license found in the LICENSE file.
+
+
+
+Benchmarks.
+
+The golang/snappy benchmarks include compressing (Z) and decompressing (U) ten
+or so files, the same set used by the C++ Snappy code (github.com/google/snappy
+and note the "google", not "golang"). On an "Intel(R) Core(TM) i7-3770 CPU @
+3.40GHz", Go's GOARCH=amd64 numbers as of 2016-05-29:
+
+"go test -test.bench=."
+
+_UFlat0-8         2.19GB/s ± 0%  html
+_UFlat1-8         1.41GB/s ± 0%  urls
+_UFlat2-8         23.5GB/s ± 2%  jpg
+_UFlat3-8         1.91GB/s ± 0%  jpg_200
+_UFlat4-8         14.0GB/s ± 1%  pdf
+_UFlat5-8         1.97GB/s ± 0%  html4
+_UFlat6-8          814MB/s ± 0%  txt1
+_UFlat7-8          785MB/s ± 0%  txt2
+_UFlat8-8          857MB/s ± 0%  txt3
+_UFlat9-8          719MB/s ± 1%  txt4
+_UFlat10-8        2.84GB/s ± 0%  pb
+_UFlat11-8        1.05GB/s ± 0%  gaviota
+
+_ZFlat0-8         1.04GB/s ± 0%  html
+_ZFlat1-8          534MB/s ± 0%  urls
+_ZFlat2-8         15.7GB/s ± 1%  jpg
+_ZFlat3-8          740MB/s ± 3%  jpg_200
+_ZFlat4-8         9.20GB/s ± 1%  pdf
+_ZFlat5-8          991MB/s ± 0%  html4
+_ZFlat6-8          379MB/s ± 0%  txt1
+_ZFlat7-8          352MB/s ± 0%  txt2
+_ZFlat8-8          396MB/s ± 1%  txt3
+_ZFlat9-8          327MB/s ± 1%  txt4
+_ZFlat10-8        1.33GB/s ± 1%  pb
+_ZFlat11-8         605MB/s ± 1%  gaviota
+
+
+
+"go test -test.bench=. -tags=noasm"
+
+_UFlat0-8          621MB/s ± 2%  html
+_UFlat1-8          494MB/s ± 1%  urls
+_UFlat2-8         23.2GB/s ± 1%  jpg
+_UFlat3-8         1.12GB/s ± 1%  jpg_200
+_UFlat4-8         4.35GB/s ± 1%  pdf
+_UFlat5-8          609MB/s ± 0%  html4
+_UFlat6-8          296MB/s ± 0%  txt1
+_UFlat7-8          288MB/s ± 0%  txt2
+_UFlat8-8          309MB/s ± 1%  txt3
+_UFlat9-8          280MB/s ± 1%  txt4
+_UFlat10-8         753MB/s ± 0%  pb
+_UFlat11-8         400MB/s ± 0%  gaviota
+
+_ZFlat0-8          409MB/s ± 1%  html
+_ZFlat1-8          250MB/s ± 1%  urls
+_ZFlat2-8         12.3GB/s ± 1%  jpg
+_ZFlat3-8          132MB/s ± 0%  jpg_200
+_ZFlat4-8         2.92GB/s ± 0%  pdf
+_ZFlat5-8          405MB/s ± 1%  html4
+_ZFlat6-8          179MB/s ± 1%  txt1
+_ZFlat7-8          170MB/s ± 1%  txt2
+_ZFlat8-8          189MB/s ± 1%  txt3
+_ZFlat9-8          164MB/s ± 1%  txt4
+_ZFlat10-8         479MB/s ± 1%  pb
+_ZFlat11-8         270MB/s ± 1%  gaviota
+
+
+
+For comparison (Go's encoded output is byte-for-byte identical to C++'s), here
+are the numbers from C++ Snappy's
+
+make CXXFLAGS="-O2 -DNDEBUG -g" clean snappy_unittest.log && cat snappy_unittest.log
+
+BM_UFlat/0     2.4GB/s  html
+BM_UFlat/1     1.4GB/s  urls
+BM_UFlat/2    21.8GB/s  jpg
+BM_UFlat/3     1.5GB/s  jpg_200
+BM_UFlat/4    13.3GB/s  pdf
+BM_UFlat/5     2.1GB/s  html4
+BM_UFlat/6     1.0GB/s  txt1
+BM_UFlat/7   959.4MB/s  txt2
+BM_UFlat/8     1.0GB/s  txt3
+BM_UFlat/9   864.5MB/s  txt4
+BM_UFlat/10    2.9GB/s  pb
+BM_UFlat/11    1.2GB/s  gaviota
+
+BM_ZFlat/0   944.3MB/s  html (22.31 %)
+BM_ZFlat/1   501.6MB/s  urls (47.78 %)
+BM_ZFlat/2    14.3GB/s  jpg (99.95 %)
+BM_ZFlat/3   538.3MB/s  jpg_200 (73.00 %)
+BM_ZFlat/4     8.3GB/s  pdf (83.30 %)
+BM_ZFlat/5   903.5MB/s  html4 (22.52 %)
+BM_ZFlat/6   336.0MB/s  txt1 (57.88 %)
+BM_ZFlat/7   312.3MB/s  txt2 (61.91 %)
+BM_ZFlat/8   353.1MB/s  txt3 (54.99 %)
+BM_ZFlat/9   289.9MB/s  txt4 (66.26 %)
+BM_ZFlat/10    1.2GB/s  pb (19.68 %)
+BM_ZFlat/11  527.4MB/s  gaviota (37.72 %)

vendor/github.com/golang/snappy/decode.go

@@ -0,0 +1,237 @@
+// Copyright 2011 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package snappy
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+)
+
+var (
+	// ErrCorrupt reports that the input is invalid.
+	ErrCorrupt = errors.New("snappy: corrupt input")
+	// ErrTooLarge reports that the uncompressed length is too large.
+	ErrTooLarge = errors.New("snappy: decoded block is too large")
+	// ErrUnsupported reports that the input isn't supported.
+	ErrUnsupported = errors.New("snappy: unsupported input")
+
+	errUnsupportedLiteralLength = errors.New("snappy: unsupported literal length")
+)
+
+// DecodedLen returns the length of the decoded block.
+func DecodedLen(src []byte) (int, error) {
+	v, _, err := decodedLen(src)
+	return v, err
+}
+
+// decodedLen returns the length of the decoded block and the number of bytes
+// that the length header occupied.
+func decodedLen(src []byte) (blockLen, headerLen int, err error) {
+	v, n := binary.Uvarint(src)
+	if n <= 0 || v > 0xffffffff {
+		return 0, 0, ErrCorrupt
+	}
+
+	const wordSize = 32 << (^uint(0) >> 32 & 1)
+	if wordSize == 32 && v > 0x7fffffff {
+		return 0, 0, ErrTooLarge
+	}
+	return int(v), n, nil
+}
+
+const (
+	decodeErrCodeCorrupt                  = 1
+	decodeErrCodeUnsupportedLiteralLength = 2
+)
+
+// Decode returns the decoded form of src. The returned slice may be a sub-
+// slice of dst if dst was large enough to hold the entire decoded block.
+// Otherwise, a newly allocated slice will be returned.
+//
+// The dst and src must not overlap. It is valid to pass a nil dst.
+func Decode(dst, src []byte) ([]byte, error) {
+	dLen, s, err := decodedLen(src)
+	if err != nil {
+		return nil, err
+	}
+	if dLen <= len(dst) {
+		dst = dst[:dLen]
+	} else {
+		dst = make([]byte, dLen)
+	}
+	switch decode(dst, src[s:]) {
+	case 0:
+		return dst, nil
+	case decodeErrCodeUnsupportedLiteralLength:
+		return nil, errUnsupportedLiteralLength
+	}
+	return nil, ErrCorrupt
+}
+
+// NewReader returns a new Reader that decompresses from r, using the framing
+// format described at
+// https://github.com/google/snappy/blob/master/framing_format.txt
+func NewReader(r io.Reader) *Reader {
+	return &Reader{
+		r:       r,
+		decoded: make([]byte, maxBlockSize),
+		buf:     make([]byte, maxEncodedLenOfMaxBlockSize+checksumSize),
+	}
+}
+
+// Reader is an io.Reader that can read Snappy-compressed bytes.
+type Reader struct {
+	r       io.Reader
+	err     error
+	decoded []byte
+	buf     []byte
+	// decoded[i:j] contains decoded bytes that have not yet been passed on.
+	i, j       int
+	readHeader bool
+}
+
+// Reset discards any buffered data, resets all state, and switches the Snappy
+// reader to read from r. This permits reusing a Reader rather than allocating
+// a new one.
+func (r *Reader) Reset(reader io.Reader) {
+	r.r = reader
+	r.err = nil
+	r.i = 0
+	r.j = 0
+	r.readHeader = false
+}
+
+func (r *Reader) readFull(p []byte, allowEOF bool) (ok bool) {
+	if _, r.err = io.ReadFull(r.r, p); r.err != nil {
+		if r.err == io.ErrUnexpectedEOF || (r.err == io.EOF && !allowEOF) {
+			r.err = ErrCorrupt
+		}
+		return false
+	}
+	return true
+}
+
+// Read satisfies the io.Reader interface.
+func (r *Reader) Read(p []byte) (int, error) {
+	if r.err != nil {
+		return 0, r.err
+	}
+	for {
+		if r.i < r.j {
+			n := copy(p, r.decoded[r.i:r.j])
+			r.i += n
+			return n, nil
+		}
+		if !r.readFull(r.buf[:4], true) {
+			return 0, r.err
+		}
+		chunkType := r.buf[0]
+		if !r.readHeader {
+			if chunkType != chunkTypeStreamIdentifier {
+				r.err = ErrCorrupt
+				return 0, r.err
+			}
+			r.readHeader = true
+		}
+		chunkLen := int(r.buf[1]) | int(r.buf[2])<<8 | int(r.buf[3])<<16
+		if chunkLen > len(r.buf) {
+			r.err = ErrUnsupported
+			return 0, r.err
+		}
+
+		// The chunk types are specified at
+		// https://github.com/google/snappy/blob/master/framing_format.txt
+		switch chunkType {
+		case chunkTypeCompressedData:
+			// Section 4.2. Compressed data (chunk type 0x00).
+			if chunkLen < checksumSize {
+				r.err = ErrCorrupt
+				return 0, r.err
+			}
+			buf := r.buf[:chunkLen]
+			if !r.readFull(buf, false) {
+				return 0, r.err
+			}
+			checksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24
+			buf = buf[checksumSize:]
+
+			n, err := DecodedLen(buf)
+			if err != nil {
+				r.err = err
+				return 0, r.err
+			}
+			if n > len(r.decoded) {
+				r.err = ErrCorrupt
+				return 0, r.err
+			}
+			if _, err := Decode(r.decoded, buf); err != nil {
+				r.err = err
+				return 0, r.err
+			}
+			if crc(r.decoded[:n]) != checksum {
+				r.err = ErrCorrupt
+				return 0, r.err
+			}
+			r.i, r.j = 0, n
+			continue
+
+		case chunkTypeUncompressedData:
+			// Section 4.3. Uncompressed data (chunk type 0x01).
+			if chunkLen < checksumSize {
+				r.err = ErrCorrupt
+				return 0, r.err
+			}
+			buf := r.buf[:checksumSize]
+			if !r.readFull(buf, false) {
+				return 0, r.err
+			}
+			checksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24
+			// Read directly into r.decoded instead of via r.buf.
+			n := chunkLen - checksumSize
+			if n > len(r.decoded) {
+				r.err = ErrCorrupt
+				return 0, r.err
+			}
+			if !r.readFull(r.decoded[:n], false) {
+				return 0, r.err
+			}
+			if crc(r.decoded[:n]) != checksum {
+				r.err = ErrCorrupt
+				return 0, r.err
+			}
+			r.i, r.j = 0, n
+			continue
+
+		case chunkTypeStreamIdentifier:
+			// Section 4.1. Stream identifier (chunk type 0xff).
+			if chunkLen != len(magicBody) {
+				r.err = ErrCorrupt
+				return 0, r.err
+			}
+			if !r.readFull(r.buf[:len(magicBody)], false) {
+				return 0, r.err
+			}
+			for i := 0; i < len(magicBody); i++ {
+				if r.buf[i] != magicBody[i] {
+					r.err = ErrCorrupt
+					return 0, r.err
+				}
+			}
+			continue
+		}
+
+		if chunkType <= 0x7f {
+			// Section 4.5. Reserved unskippable chunks (chunk types 0x02-0x7f).
+			r.err = ErrUnsupported
+			return 0, r.err
+		}
+		// Section 4.4 Padding (chunk type 0xfe).
+		// Section 4.6. Reserved skippable chunks (chunk types 0x80-0xfd).
+		if !r.readFull(r.buf[:chunkLen], false) {
+			return 0, r.err
+		}
+	}
+}

vendor/github.com/golang/snappy/decode_amd64.go

@@ -0,0 +1,14 @@
+// Copyright 2016 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !appengine
+// +build gc
+// +build !noasm
+
+package snappy
+
+// decode has the same semantics as in decode_other.go.
+//
+//go:noescape
+func decode(dst, src []byte) int

vendor/github.com/golang/snappy/decode_amd64.s

@@ -0,0 +1,490 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !appengine
+// +build gc
+// +build !noasm
+
+#include "textflag.h"
+
+// The asm code generally follows the pure Go code in decode_other.go, except
+// where marked with a "!!!".
+
+// func decode(dst, src []byte) int
+//
+// All local variables fit into registers. The non-zero stack size is only to
+// spill registers and push args when issuing a CALL. The register allocation:
+//	- AX	scratch
+//	- BX	scratch
+//	- CX	length or x
+//	- DX	offset
+//	- SI	&src[s]
+//	- DI	&dst[d]
+//	+ R8	dst_base
+//	+ R9	dst_len
+//	+ R10	dst_base + dst_len
+//	+ R11	src_base
+//	+ R12	src_len
+//	+ R13	src_base + src_len
+//	- R14	used by doCopy
+//	- R15	used by doCopy
+//
+// The registers R8-R13 (marked with a "+") are set at the start of the
+// function, and after a CALL returns, and are not otherwise modified.
+//
+// The d variable is implicitly DI - R8,  and len(dst)-d is R10 - DI.
+// The s variable is implicitly SI - R11, and len(src)-s is R13 - SI.
+TEXT ·decode(SB), NOSPLIT, $48-56
+	// Initialize SI, DI and R8-R13.
+	MOVQ dst_base+0(FP), R8
+	MOVQ dst_len+8(FP), R9
+	MOVQ R8, DI
+	MOVQ R8, R10
+	ADDQ R9, R10
+	MOVQ src_base+24(FP), R11
+	MOVQ src_len+32(FP), R12
+	MOVQ R11, SI
+	MOVQ R11, R13
+	ADDQ R12, R13
+
+loop:
+	// for s < len(src)
+	CMPQ SI, R13
+	JEQ  end
+
+	// CX = uint32(src[s])
+	//
+	// switch src[s] & 0x03
+	MOVBLZX (SI), CX
+	MOVL    CX, BX
+	ANDL    $3, BX
+	CMPL    BX, $1
+	JAE     tagCopy
+
+	// ----------------------------------------
+	// The code below handles literal tags.
+
+	// case tagLiteral:
+	// x := uint32(src[s] >> 2)
+	// switch
+	SHRL $2, CX
+	CMPL CX, $60
+	JAE  tagLit60Plus
+
+	// case x < 60:
+	// s++
+	INCQ SI
+
+doLit:
+	// This is the end of the inner "switch", when we have a literal tag.
+	//
+	// We assume that CX == x and x fits in a uint32, where x is the variable
+	// used in the pure Go decode_other.go code.
+
+	// length = int(x) + 1
+	//
+	// Unlike the pure Go code, we don't need to check if length <= 0 because
+	// CX can hold 64 bits, so the increment cannot overflow.
+	INCQ CX
+
+	// Prepare to check if copying length bytes will run past the end of dst or
+	// src.
+	//
+	// AX = len(dst) - d
+	// BX = len(src) - s
+	MOVQ R10, AX
+	SUBQ DI, AX
+	MOVQ R13, BX
+	SUBQ SI, BX
+
+	// !!! Try a faster technique for short (16 or fewer bytes) copies.
+	//
+	// if length > 16 || len(dst)-d < 16 || len(src)-s < 16 {
+	//   goto callMemmove // Fall back on calling runtime·memmove.
+	// }
+	//
+	// The C++ snappy code calls this TryFastAppend. It also checks len(src)-s
+	// against 21 instead of 16, because it cannot assume that all of its input
+	// is contiguous in memory and so it needs to leave enough source bytes to
+	// read the next tag without refilling buffers, but Go's Decode assumes
+	// contiguousness (the src argument is a []byte).
+	CMPQ CX, $16
+	JGT  callMemmove
+	CMPQ AX, $16
+	JLT  callMemmove
+	CMPQ BX, $16
+	JLT  callMemmove
+
+	// !!! Implement the copy from src to dst as a 16-byte load and store.
+	// (Decode's documentation says that dst and src must not overlap.)
+	//
+	// This always copies 16 bytes, instead of only length bytes, but that's
+	// OK. If the input is a valid Snappy encoding then subsequent iterations
+	// will fix up the overrun. Otherwise, Decode returns a nil []byte (and a
+	// non-nil error), so the overrun will be ignored.
+	//
+	// Note that on amd64, it is legal and cheap to issue unaligned 8-byte or
+	// 16-byte loads and stores. This technique probably wouldn't be as
+	// effective on architectures that are fussier about alignment.
+	MOVOU 0(SI), X0
+	MOVOU X0, 0(DI)
+
+	// d += length
+	// s += length
+	ADDQ CX, DI
+	ADDQ CX, SI
+	JMP  loop
+
+callMemmove:
+	// if length > len(dst)-d || length > len(src)-s { etc }
+	CMPQ CX, AX
+	JGT  errCorrupt
+	CMPQ CX, BX
+	JGT  errCorrupt
+
+	// copy(dst[d:], src[s:s+length])
+	//
+	// This means calling runtime·memmove(&dst[d], &src[s], length), so we push
+	// DI, SI and CX as arguments. Coincidentally, we also need to spill those
+	// three registers to the stack, to save local variables across the CALL.
+	MOVQ DI, 0(SP)
+	MOVQ SI, 8(SP)
+	MOVQ CX, 16(SP)
+	MOVQ DI, 24(SP)
+	MOVQ SI, 32(SP)
+	MOVQ CX, 40(SP)
+	CALL runtime·memmove(SB)
+
+	// Restore local variables: unspill registers from the stack and
+	// re-calculate R8-R13.
+	MOVQ 24(SP), DI
+	MOVQ 32(SP), SI
+	MOVQ 40(SP), CX
+	MOVQ dst_base+0(FP), R8
+	MOVQ dst_len+8(FP), R9
+	MOVQ R8, R10
+	ADDQ R9, R10
+	MOVQ src_base+24(FP), R11
+	MOVQ src_len+32(FP), R12
+	MOVQ R11, R13
+	ADDQ R12, R13
+
+	// d += length
+	// s += length
+	ADDQ CX, DI
+	ADDQ CX, SI
+	JMP  loop
+
+tagLit60Plus:
+	// !!! This fragment does the
+	//
+	// s += x - 58; if uint(s) > uint(len(src)) { etc }
+	//
+	// checks. In the asm version, we code it once instead of once per switch case.
+	ADDQ CX, SI
+	SUBQ $58, SI
+	MOVQ SI, BX
+	SUBQ R11, BX
+	CMPQ BX, R12
+	JA   errCorrupt
+
+	// case x == 60:
+	CMPL CX, $61
+	JEQ  tagLit61
+	JA   tagLit62Plus
+
+	// x = uint32(src[s-1])
+	MOVBLZX -1(SI), CX
+	JMP     doLit
+
+tagLit61:
+	// case x == 61:
+	// x = uint32(src[s-2]) | uint32(src[s-1])<<8
+	MOVWLZX -2(SI), CX
+	JMP     doLit
+
+tagLit62Plus:
+	CMPL CX, $62
+	JA   tagLit63
+
+	// case x == 62:
+	// x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
+	MOVWLZX -3(SI), CX
+	MOVBLZX -1(SI), BX
+	SHLL    $16, BX
+	ORL     BX, CX
+	JMP     doLit
+
+tagLit63:
+	// case x == 63:
+	// x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
+	MOVL -4(SI), CX
+	JMP  doLit
+
+// The code above handles literal tags.
+// ----------------------------------------
+// The code below handles copy tags.
+
+tagCopy4:
+	// case tagCopy4:
+	// s += 5
+	ADDQ $5, SI
+
+	// if uint(s) > uint(len(src)) { etc }
+	MOVQ SI, BX
+	SUBQ R11, BX
+	CMPQ BX, R12
+	JA   errCorrupt
+
+	// length = 1 + int(src[s-5])>>2
+	SHRQ $2, CX
+	INCQ CX
+
+	// offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
+	MOVLQZX -4(SI), DX
+	JMP     doCopy
+
+tagCopy2:
+	// case tagCopy2:
+	// s += 3
+	ADDQ $3, SI
+
+	// if uint(s) > uint(len(src)) { etc }
+	MOVQ SI, BX
+	SUBQ R11, BX
+	CMPQ BX, R12
+	JA   errCorrupt
+
+	// length = 1 + int(src[s-3])>>2
+	SHRQ $2, CX
+	INCQ CX
+
+	// offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
+	MOVWQZX -2(SI), DX
+	JMP     doCopy
+
+tagCopy:
+	// We have a copy tag. We assume that:
+	//	- BX == src[s] & 0x03
+	//	- CX == src[s]
+	CMPQ BX, $2
+	JEQ  tagCopy2
+	JA   tagCopy4
+
+	// case tagCopy1:
+	// s += 2
+	ADDQ $2, SI
+
+	// if uint(s) > uint(len(src)) { etc }
+	MOVQ SI, BX
+	SUBQ R11, BX
+	CMPQ BX, R12
+	JA   errCorrupt
+
+	// offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
+	MOVQ    CX, DX
+	ANDQ    $0xe0, DX
+	SHLQ    $3, DX
+	MOVBQZX -1(SI), BX
+	ORQ     BX, DX
+
+	// length = 4 + int(src[s-2])>>2&0x7
+	SHRQ $2, CX
+	ANDQ $7, CX
+	ADDQ $4, CX
+
+doCopy:
+	// This is the end of the outer "switch", when we have a copy tag.
+	//
+	// We assume that:
+	//	- CX == length && CX > 0
+	//	- DX == offset
+
+	// if offset <= 0 { etc }
+	CMPQ DX, $0
+	JLE  errCorrupt
+
+	// if d < offset { etc }
+	MOVQ DI, BX
+	SUBQ R8, BX
+	CMPQ BX, DX
+	JLT  errCorrupt
+
+	// if length > len(dst)-d { etc }
+	MOVQ R10, BX
+	SUBQ DI, BX
+	CMPQ CX, BX
+	JGT  errCorrupt
+
+	// forwardCopy(dst[d:d+length], dst[d-offset:]); d += length
+	//
+	// Set:
+	//	- R14 = len(dst)-d
+	//	- R15 = &dst[d-offset]
+	MOVQ R10, R14
+	SUBQ DI, R14
+	MOVQ DI, R15
+	SUBQ DX, R15
+
+	// !!! Try a faster technique for short (16 or fewer bytes) forward copies.
+	//
+	// First, try using two 8-byte load/stores, similar to the doLit technique
+	// above. Even if dst[d:d+length] and dst[d-offset:] can overlap, this is
+	// still OK if offset >= 8. Note that this has to be two 8-byte load/stores
+	// and not one 16-byte load/store, and the first store has to be before the
+	// second load, due to the overlap if offset is in the range [8, 16).
+	//
+	// if length > 16 || offset < 8 || len(dst)-d < 16 {
+	//   goto slowForwardCopy
+	// }
+	// copy 16 bytes
+	// d += length
+	CMPQ CX, $16
+	JGT  slowForwardCopy
+	CMPQ DX, $8
+	JLT  slowForwardCopy
+	CMPQ R14, $16
+	JLT  slowForwardCopy
+	MOVQ 0(R15), AX
+	MOVQ AX, 0(DI)
+	MOVQ 8(R15), BX
+	MOVQ BX, 8(DI)
+	ADDQ CX, DI
+	JMP  loop
+
+slowForwardCopy:
+	// !!! If the forward copy is longer than 16 bytes, or if offset < 8, we
+	// can still try 8-byte load stores, provided we can overrun up to 10 extra
+	// bytes. As above, the overrun will be fixed up by subsequent iterations
+	// of the outermost loop.
+	//
+	// The C++ snappy code calls this technique IncrementalCopyFastPath. Its
+	// commentary says:
+	//
+	// ----
+	//
+	// The main part of this loop is a simple copy of eight bytes at a time
+	// until we've copied (at least) the requested amount of bytes.  However,
+	// if d and d-offset are less than eight bytes apart (indicating a
+	// repeating pattern of length < 8), we first need to expand the pattern in
+	// order to get the correct results. For instance, if the buffer looks like
+	// this, with the eight-byte <d-offset> and <d> patterns marked as
+	// intervals:
+	//
+	//    abxxxxxxxxxxxx
+	//    [------]           d-offset
+	//      [------]         d
+	//
+	// a single eight-byte copy from <d-offset> to <d> will repeat the pattern
+	// once, after which we can move <d> two bytes without moving <d-offset>:
+	//
+	//    ababxxxxxxxxxx
+	//    [------]           d-offset
+	//        [------]       d
+	//
+	// and repeat the exercise until the two no longer overlap.
+	//
+	// This allows us to do very well in the special case of one single byte
+	// repeated many times, without taking a big hit for more general cases.
+	//
+	// The worst case of extra writing past the end of the match occurs when
+	// offset == 1 and length == 1; the last copy will read from byte positions
+	// [0..7] and write to [4..11], whereas it was only supposed to write to
+	// position 1. Thus, ten excess bytes.
+	//
+	// ----
+	//
+	// That "10 byte overrun" worst case is confirmed by Go's
+	// TestSlowForwardCopyOverrun, which also tests the fixUpSlowForwardCopy
+	// and finishSlowForwardCopy algorithm.
+	//
+	// if length > len(dst)-d-10 {
+	//   goto verySlowForwardCopy
+	// }
+	SUBQ $10, R14
+	CMPQ CX, R14
+	JGT  verySlowForwardCopy
+
+makeOffsetAtLeast8:
+	// !!! As above, expand the pattern so that offset >= 8 and we can use
+	// 8-byte load/stores.
+	//
+	// for offset < 8 {
+	//   copy 8 bytes from dst[d-offset:] to dst[d:]
+	//   length -= offset
+	//   d      += offset
+	//   offset += offset
+	//   // The two previous lines together means that d-offset, and therefore
+	//   // R15, is unchanged.
+	// }
+	CMPQ DX, $8
+	JGE  fixUpSlowForwardCopy
+	MOVQ (R15), BX
+	MOVQ BX, (DI)
+	SUBQ DX, CX
+	ADDQ DX, DI
+	ADDQ DX, DX
+	JMP  makeOffsetAtLeast8
+
+fixUpSlowForwardCopy:
+	// !!! Add length (which might be negative now) to d (implied by DI being
+	// &dst[d]) so that d ends up at the right place when we jump back to the
+	// top of the loop. Before we do that, though, we save DI to AX so that, if
+	// length is positive, copying the remaining length bytes will write to the
+	// right place.
+	MOVQ DI, AX
+	ADDQ CX, DI
+
+finishSlowForwardCopy:
+	// !!! Repeat 8-byte load/stores until length <= 0. Ending with a negative
+	// length means that we overrun, but as above, that will be fixed up by
+	// subsequent iterations of the outermost loop.
+	CMPQ CX, $0
+	JLE  loop
+	MOVQ (R15), BX
+	MOVQ BX, (AX)
+	ADDQ $8, R15
+	ADDQ $8, AX
+	SUBQ $8, CX
+	JMP  finishSlowForwardCopy
+
+verySlowForwardCopy:
+	// verySlowForwardCopy is a simple implementation of forward copy. In C
+	// parlance, this is a do/while loop instead of a while loop, since we know
+	// that length > 0. In Go syntax:
+	//
+	// for {
+	//   dst[d] = dst[d - offset]
+	//   d++
+	//   length--
+	//   if length == 0 {
+	//     break
+	//   }
+	// }
+	MOVB (R15), BX
+	MOVB BX, (DI)
+	INCQ R15
+	INCQ DI
+	DECQ CX
+	JNZ  verySlowForwardCopy
+	JMP  loop
+
+// The code above handles copy tags.
+// ----------------------------------------
+
+end:
+	// This is the end of the "for s < len(src)".
+	//
+	// if d != len(dst) { etc }
+	CMPQ DI, R10
+	JNE  errCorrupt
+
+	// return 0
+	MOVQ $0, ret+48(FP)
+	RET
+
+errCorrupt:
+	// return decodeErrCodeCorrupt
+	MOVQ $1, ret+48(FP)
+	RET

vendor/github.com/golang/snappy/decode_other.go

@@ -0,0 +1,101 @@
+// Copyright 2016 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !amd64 appengine !gc noasm
+
+package snappy
+
+// decode writes the decoding of src to dst. It assumes that the varint-encoded
+// length of the decompressed bytes has already been read, and that len(dst)
+// equals that length.
+//
+// It returns 0 on success or a decodeErrCodeXxx error code on failure.
+func decode(dst, src []byte) int {
+	var d, s, offset, length int
+	for s < len(src) {
+		switch src[s] & 0x03 {
+		case tagLiteral:
+			x := uint32(src[s] >> 2)
+			switch {
+			case x < 60:
+				s++
+			case x == 60:
+				s += 2
+				if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
+					return decodeErrCodeCorrupt
+				}
+				x = uint32(src[s-1])
+			case x == 61:
+				s += 3
+				if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
+					return decodeErrCodeCorrupt
+				}
+				x = uint32(src[s-2]) | uint32(src[s-1])<<8
+			case x == 62:
+				s += 4
+				if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
+					return decodeErrCodeCorrupt
+				}
+				x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
+			case x == 63:
+				s += 5
+				if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
+					return decodeErrCodeCorrupt
+				}
+				x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
+			}
+			length = int(x) + 1
+			if length <= 0 {
+				return decodeErrCodeUnsupportedLiteralLength
+			}
+			if length > len(dst)-d || length > len(src)-s {
+				return decodeErrCodeCorrupt
+			}
+			copy(dst[d:], src[s:s+length])
+			d += length
+			s += length
+			continue
+
+		case tagCopy1:
+			s += 2
+			if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
+				return decodeErrCodeCorrupt
+			}
+			length = 4 + int(src[s-2])>>2&0x7
+			offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
+
+		case tagCopy2:
+			s += 3
+			if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
+				return decodeErrCodeCorrupt
+			}
+			length = 1 + int(src[s-3])>>2
+			offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
+
+		case tagCopy4:
+			s += 5
+			if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
+				return decodeErrCodeCorrupt
+			}
+			length = 1 + int(src[s-5])>>2
+			offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
+		}
+
+		if offset <= 0 || d < offset || length > len(dst)-d {
+			return decodeErrCodeCorrupt
+		}
+		// Copy from an earlier sub-slice of dst to a later sub-slice. Unlike
+		// the built-in copy function, this byte-by-byte copy always runs
+		// forwards, even if the slices overlap. Conceptually, this is:
+		//
+		// d += forwardCopy(dst[d:d+length], dst[d-offset:])
+		for end := d + length; d != end; d++ {
+			dst[d] = dst[d-offset]
+		}
+	}
+	if d != len(dst) {
+		return decodeErrCodeCorrupt
+	}
+	return 0
+}

vendor/github.com/golang/snappy/encode.go

@@ -0,0 +1,285 @@
+// Copyright 2011 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package snappy
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+)
+
+// Encode returns the encoded form of src. The returned slice may be a sub-
+// slice of dst if dst was large enough to hold the entire encoded block.
+// Otherwise, a newly allocated slice will be returned.
+//
+// The dst and src must not overlap. It is valid to pass a nil dst.
+func Encode(dst, src []byte) []byte {
+	if n := MaxEncodedLen(len(src)); n < 0 {
+		panic(ErrTooLarge)
+	} else if len(dst) < n {
+		dst = make([]byte, n)
+	}
+
+	// The block starts with the varint-encoded length of the decompressed bytes.
+	d := binary.PutUvarint(dst, uint64(len(src)))
+
+	for len(src) > 0 {
+		p := src
+		src = nil
+		if len(p) > maxBlockSize {
+			p, src = p[:maxBlockSize], p[maxBlockSize:]
+		}
+		if len(p) < minNonLiteralBlockSize {
+			d += emitLiteral(dst[d:], p)
+		} else {
+			d += encodeBlock(dst[d:], p)
+		}
+	}
+	return dst[:d]
+}
+
+// inputMargin is the minimum number of extra input bytes to keep, inside
+// encodeBlock's inner loop. On some architectures, this margin lets us
+// implement a fast path for emitLiteral, where the copy of short (<= 16 byte)
+// literals can be implemented as a single load to and store from a 16-byte
+// register. That literal's actual length can be as short as 1 byte, so this
+// can copy up to 15 bytes too much, but that's OK as subsequent iterations of
+// the encoding loop will fix up the copy overrun, and this inputMargin ensures
+// that we don't overrun the dst and src buffers.
+const inputMargin = 16 - 1
+
+// minNonLiteralBlockSize is the minimum size of the input to encodeBlock that
+// could be encoded with a copy tag. This is the minimum with respect to the
+// algorithm used by encodeBlock, not a minimum enforced by the file format.
+//
+// The encoded output must start with at least a 1 byte literal, as there are
+// no previous bytes to copy. A minimal (1 byte) copy after that, generated
+// from an emitCopy call in encodeBlock's main loop, would require at least
+// another inputMargin bytes, for the reason above: we want any emitLiteral
+// calls inside encodeBlock's main loop to use the fast path if possible, which
+// requires being able to overrun by inputMargin bytes. Thus,
+// minNonLiteralBlockSize equals 1 + 1 + inputMargin.
+//
+// The C++ code doesn't use this exact threshold, but it could, as discussed at
+// https://groups.google.com/d/topic/snappy-compression/oGbhsdIJSJ8/discussion
+// The difference between Go (2+inputMargin) and C++ (inputMargin) is purely an
+// optimization. It should not affect the encoded form. This is tested by
+// TestSameEncodingAsCppShortCopies.
+const minNonLiteralBlockSize = 1 + 1 + inputMargin
+
+// MaxEncodedLen returns the maximum length of a snappy block, given its
+// uncompressed length.
+//
+// It will return a negative value if srcLen is too large to encode.
+func MaxEncodedLen(srcLen int) int {
+	n := uint64(srcLen)
+	if n > 0xffffffff {
+		return -1
+	}
+	// Compressed data can be defined as:
+	//    compressed := item* literal*
+	//    item       := literal* copy
+	//
+	// The trailing literal sequence has a space blowup of at most 62/60
+	// since a literal of length 60 needs one tag byte + one extra byte
+	// for length information.
+	//
+	// Item blowup is trickier to measure. Suppose the "copy" op copies
+	// 4 bytes of data. Because of a special check in the encoding code,
+	// we produce a 4-byte copy only if the offset is < 65536. Therefore
+	// the copy op takes 3 bytes to encode, and this type of item leads
+	// to at most the 62/60 blowup for representing literals.
+	//
+	// Suppose the "copy" op copies 5 bytes of data. If the offset is big
+	// enough, it will take 5 bytes to encode the copy op. Therefore the
+	// worst case here is a one-byte literal followed by a five-byte copy.
+	// That is, 6 bytes of input turn into 7 bytes of "compressed" data.
+	//
+	// This last factor dominates the blowup, so the final estimate is:
+	n = 32 + n + n/6
+	if n > 0xffffffff {
+		return -1
+	}
+	return int(n)
+}
+
+var errClosed = errors.New("snappy: Writer is closed")
+
+// NewWriter returns a new Writer that compresses to w.
+//
+// The Writer returned does not buffer writes. There is no need to Flush or
+// Close such a Writer.
+//
+// Deprecated: the Writer returned is not suitable for many small writes, only
+// for few large writes. Use NewBufferedWriter instead, which is efficient
+// regardless of the frequency and shape of the writes, and remember to Close
+// that Writer when done.
+func NewWriter(w io.Writer) *Writer {
+	return &Writer{
+		w:    w,
+		obuf: make([]byte, obufLen),
+	}
+}
+
+// NewBufferedWriter returns a new Writer that compresses to w, using the
+// framing format described at
+// https://github.com/google/snappy/blob/master/framing_format.txt
+//
+// The Writer returned buffers writes. Users must call Close to guarantee all
+// data has been forwarded to the underlying io.Writer. They may also call
+// Flush zero or more times before calling Close.
+func NewBufferedWriter(w io.Writer) *Writer {
+	return &Writer{
+		w:    w,
+		ibuf: make([]byte, 0, maxBlockSize),
+		obuf: make([]byte, obufLen),
+	}
+}
+
+// Writer is an io.Writer that can write Snappy-compressed bytes.
+type Writer struct {
+	w   io.Writer
+	err error
+
+	// ibuf is a buffer for the incoming (uncompressed) bytes.
+	//
+	// Its use is optional. For backwards compatibility, Writers created by the
+	// NewWriter function have ibuf == nil, do not buffer incoming bytes, and
+	// therefore do not need to be Flush'ed or Close'd.
+	ibuf []byte
+
+	// obuf is a buffer for the outgoing (compressed) bytes.
+	obuf []byte
+
+	// wroteStreamHeader is whether we have written the stream header.
+	wroteStreamHeader bool
+}
+
+// Reset discards the writer's state and switches the Snappy writer to write to
+// w. This permits reusing a Writer rather than allocating a new one.
+func (w *Writer) Reset(writer io.Writer) {
+	w.w = writer
+	w.err = nil
+	if w.ibuf != nil {
+		w.ibuf = w.ibuf[:0]
+	}
+	w.wroteStreamHeader = false
+}
+
+// Write satisfies the io.Writer interface.
+func (w *Writer) Write(p []byte) (nRet int, errRet error) {
+	if w.ibuf == nil {
+		// Do not buffer incoming bytes. This does not perform or compress well
+		// if the caller of Writer.Write writes many small slices. This
+		// behavior is therefore deprecated, but still supported for backwards
+		// compatibility with code that doesn't explicitly Flush or Close.
+		return w.write(p)
+	}
+
+	// The remainder of this method is based on bufio.Writer.Write from the
+	// standard library.
+
+	for len(p) > (cap(w.ibuf)-len(w.ibuf)) && w.err == nil {
+		var n int
+		if len(w.ibuf) == 0 {
+			// Large write, empty buffer.
+			// Write directly from p to avoid copy.
+			n, _ = w.write(p)
+		} else {
+			n = copy(w.ibuf[len(w.ibuf):cap(w.ibuf)], p)
+			w.ibuf = w.ibuf[:len(w.ibuf)+n]
+			w.Flush()
+		}
+		nRet += n
+		p = p[n:]
+	}
+	if w.err != nil {
+		return nRet, w.err
+	}
+	n := copy(w.ibuf[len(w.ibuf):cap(w.ibuf)], p)
+	w.ibuf = w.ibuf[:len(w.ibuf)+n]
+	nRet += n
+	return nRet, nil
+}
+
+func (w *Writer) write(p []byte) (nRet int, errRet error) {
+	if w.err != nil {
+		return 0, w.err
+	}
+	for len(p) > 0 {
+		obufStart := len(magicChunk)
+		if !w.wroteStreamHeader {
+			w.wroteStreamHeader = true
+			copy(w.obuf, magicChunk)
+			obufStart = 0
+		}
+
+		var uncompressed []byte
+		if len(p) > maxBlockSize {
+			uncompressed, p = p[:maxBlockSize], p[maxBlockSize:]
+		} else {
+			uncompressed, p = p, nil
+		}
+		checksum := crc(uncompressed)
+
+		// Compress the buffer, discarding the result if the improvement
+		// isn't at least 12.5%.
+		compressed := Encode(w.obuf[obufHeaderLen:], uncompressed)
+		chunkType := uint8(chunkTypeCompressedData)
+		chunkLen := 4 + len(compressed)
+		obufEnd := obufHeaderLen + len(compressed)
+		if len(compressed) >= len(uncompressed)-len(uncompressed)/8 {
+			chunkType = chunkTypeUncompressedData
+			chunkLen = 4 + len(uncompressed)
+			obufEnd = obufHeaderLen
+		}
+
+		// Fill in the per-chunk header that comes before the body.
+		w.obuf[len(magicChunk)+0] = chunkType
+		w.obuf[len(magicChunk)+1] = uint8(chunkLen >> 0)
+		w.obuf[len(magicChunk)+2] = uint8(chunkLen >> 8)
+		w.obuf[len(magicChunk)+3] = uint8(chunkLen >> 16)
+		w.obuf[len(magicChunk)+4] = uint8(checksum >> 0)
+		w.obuf[len(magicChunk)+5] = uint8(checksum >> 8)
+		w.obuf[len(magicChunk)+6] = uint8(checksum >> 16)
+		w.obuf[len(magicChunk)+7] = uint8(checksum >> 24)
+
+		if _, err := w.w.Write(w.obuf[obufStart:obufEnd]); err != nil {
+			w.err = err
+			return nRet, err
+		}
+		if chunkType == chunkTypeUncompressedData {
+			if _, err := w.w.Write(uncompressed); err != nil {
+				w.err = err
+				return nRet, err
+			}
+		}
+		nRet += len(uncompressed)
+	}
+	return nRet, nil
+}
+
+// Flush flushes the Writer to its underlying io.Writer.
+func (w *Writer) Flush() error {
+	if w.err != nil {
+		return w.err
+	}
+	if len(w.ibuf) == 0 {
+		return nil
+	}
+	w.write(w.ibuf)
+	w.ibuf = w.ibuf[:0]
+	return w.err
+}
+
+// Close calls Flush and then closes the Writer.
+func (w *Writer) Close() error {
+	w.Flush()
+	ret := w.err
+	if w.err == nil {
+		w.err = errClosed
+	}
+	return ret
+}

vendor/github.com/golang/snappy/encode_amd64.go

@@ -0,0 +1,29 @@
+// Copyright 2016 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !appengine
+// +build gc
+// +build !noasm
+
+package snappy
+
+// emitLiteral has the same semantics as in encode_other.go.
+//
+//go:noescape
+func emitLiteral(dst, lit []byte) int
+
+// emitCopy has the same semantics as in encode_other.go.
+//
+//go:noescape
+func emitCopy(dst []byte, offset, length int) int
+
+// extendMatch has the same semantics as in encode_other.go.
+//
+//go:noescape
+func extendMatch(src []byte, i, j int) int
+
+// encodeBlock has the same semantics as in encode_other.go.
+//
+//go:noescape
+func encodeBlock(dst, src []byte) (d int)

vendor/github.com/golang/snappy/encode_amd64.s

@@ -0,0 +1,730 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !appengine
+// +build gc
+// +build !noasm
+
+#include "textflag.h"
+
+// The XXX lines assemble on Go 1.4, 1.5 and 1.7, but not 1.6, due to a
+// Go toolchain regression. See https://github.com/golang/go/issues/15426 and
+// https://github.com/golang/snappy/issues/29
+//
+// As a workaround, the package was built with a known good assembler, and
+// those instructions were disassembled by "objdump -d" to yield the
+//	4e 0f b7 7c 5c 78       movzwq 0x78(%rsp,%r11,2),%r15
+// style comments, in AT&T asm syntax. Note that rsp here is a physical
+// register, not Go/asm's SP pseudo-register (see https://golang.org/doc/asm).
+// The instructions were then encoded as "BYTE $0x.." sequences, which assemble
+// fine on Go 1.6.
+
+// The asm code generally follows the pure Go code in encode_other.go, except
+// where marked with a "!!!".
+
+// ----------------------------------------------------------------------------
+
+// func emitLiteral(dst, lit []byte) int
+//
+// All local variables fit into registers. The register allocation:
+//	- AX	len(lit)
+//	- BX	n
+//	- DX	return value
+//	- DI	&dst[i]
+//	- R10	&lit[0]
+//
+// The 24 bytes of stack space is to call runtime·memmove.
+//
+// The unusual register allocation of local variables, such as R10 for the
+// source pointer, matches the allocation used at the call site in encodeBlock,
+// which makes it easier to manually inline this function.
+TEXT ·emitLiteral(SB), NOSPLIT, $24-56
+	MOVQ dst_base+0(FP), DI
+	MOVQ lit_base+24(FP), R10
+	MOVQ lit_len+32(FP), AX
+	MOVQ AX, DX
+	MOVL AX, BX
+	SUBL $1, BX
+
+	CMPL BX, $60
+	JLT  oneByte
+	CMPL BX, $256
+	JLT  twoBytes
+
+threeBytes:
+	MOVB $0xf4, 0(DI)
+	MOVW BX, 1(DI)
+	ADDQ $3, DI
+	ADDQ $3, DX
+	JMP  memmove
+
+twoBytes:
+	MOVB $0xf0, 0(DI)
+	MOVB BX, 1(DI)
+	ADDQ $2, DI
+	ADDQ $2, DX
+	JMP  memmove
+
+oneByte:
+	SHLB $2, BX
+	MOVB BX, 0(DI)
+	ADDQ $1, DI
+	ADDQ $1, DX
+
+memmove:
+	MOVQ DX, ret+48(FP)
+
+	// copy(dst[i:], lit)
+	//
+	// This means calling runtime·memmove(&dst[i], &lit[0], len(lit)), so we push
+	// DI, R10 and AX as arguments.
+	MOVQ DI, 0(SP)
+	MOVQ R10, 8(SP)
+	MOVQ AX, 16(SP)
+	CALL runtime·memmove(SB)
+	RET
+
+// ----------------------------------------------------------------------------
+
+// func emitCopy(dst []byte, offset, length int) int
+//
+// All local variables fit into registers. The register allocation:
+//	- AX	length
+//	- SI	&dst[0]
+//	- DI	&dst[i]
+//	- R11	offset
+//
+// The unusual register allocation of local variables, such as R11 for the
+// offset, matches the allocation used at the call site in encodeBlock, which
+// makes it easier to manually inline this function.
+TEXT ·emitCopy(SB), NOSPLIT, $0-48
+	MOVQ dst_base+0(FP), DI
+	MOVQ DI, SI
+	MOVQ offset+24(FP), R11
+	MOVQ length+32(FP), AX
+
+loop0:
+	// for length >= 68 { etc }
+	CMPL AX, $68
+	JLT  step1
+
+	// Emit a length 64 copy, encoded as 3 bytes.
+	MOVB $0xfe, 0(DI)
+	MOVW R11, 1(DI)
+	ADDQ $3, DI
+	SUBL $64, AX
+	JMP  loop0
+
+step1:
+	// if length > 64 { etc }
+	CMPL AX, $64
+	JLE  step2
+
+	// Emit a length 60 copy, encoded as 3 bytes.
+	MOVB $0xee, 0(DI)
+	MOVW R11, 1(DI)
+	ADDQ $3, DI
+	SUBL $60, AX
+
+step2:
+	// if length >= 12 || offset >= 2048 { goto step3 }
+	CMPL AX, $12
+	JGE  step3
+	CMPL R11, $2048
+	JGE  step3
+
+	// Emit the remaining copy, encoded as 2 bytes.
+	MOVB R11, 1(DI)
+	SHRL $8, R11
+	SHLB $5, R11
+	SUBB $4, AX
+	SHLB $2, AX
+	ORB  AX, R11
+	ORB  $1, R11
+	MOVB R11, 0(DI)
+	ADDQ $2, DI
+
+	// Return the number of bytes written.
+	SUBQ SI, DI
+	MOVQ DI, ret+40(FP)
+	RET
+
+step3:
+	// Emit the remaining copy, encoded as 3 bytes.
+	SUBL $1, AX
+	SHLB $2, AX
+	ORB  $2, AX
+	MOVB AX, 0(DI)
+	MOVW R11, 1(DI)
+	ADDQ $3, DI
+
+	// Return the number of bytes written.
+	SUBQ SI, DI
+	MOVQ DI, ret+40(FP)
+	RET
+
+// ----------------------------------------------------------------------------
+
+// func extendMatch(src []byte, i, j int) int
+//
+// All local variables fit into registers. The register allocation:
+//	- DX	&src[0]
+//	- SI	&src[j]
+//	- R13	&src[len(src) - 8]
+//	- R14	&src[len(src)]
+//	- R15	&src[i]
+//
+// The unusual register allocation of local variables, such as R15 for a source
+// pointer, matches the allocation used at the call site in encodeBlock, which
+// makes it easier to manually inline this function.
+TEXT ·extendMatch(SB), NOSPLIT, $0-48
+	MOVQ src_base+0(FP), DX
+	MOVQ src_len+8(FP), R14
+	MOVQ i+24(FP), R15
+	MOVQ j+32(FP), SI
+	ADDQ DX, R14
+	ADDQ DX, R15
+	ADDQ DX, SI
+	MOVQ R14, R13
+	SUBQ $8, R13
+
+cmp8:
+	// As long as we are 8 or more bytes before the end of src, we can load and
+	// compare 8 bytes at a time. If those 8 bytes are equal, repeat.
+	CMPQ SI, R13
+	JA   cmp1
+	MOVQ (R15), AX
+	MOVQ (SI), BX
+	CMPQ AX, BX
+	JNE  bsf
+	ADDQ $8, R15
+	ADDQ $8, SI
+	JMP  cmp8
+
+bsf:
+	// If those 8 bytes were not equal, XOR the two 8 byte values, and return
+	// the index of the first byte that differs. The BSF instruction finds the
+	// least significant 1 bit, the amd64 architecture is little-endian, and
+	// the shift by 3 converts a bit index to a byte index.
+	XORQ AX, BX
+	BSFQ BX, BX
+	SHRQ $3, BX
+	ADDQ BX, SI
+
+	// Convert from &src[ret] to ret.
+	SUBQ DX, SI
+	MOVQ SI, ret+40(FP)
+	RET
+
+cmp1:
+	// In src's tail, compare 1 byte at a time.
+	CMPQ SI, R14
+	JAE  extendMatchEnd
+	MOVB (R15), AX
+	MOVB (SI), BX
+	CMPB AX, BX
+	JNE  extendMatchEnd
+	ADDQ $1, R15
+	ADDQ $1, SI
+	JMP  cmp1
+
+extendMatchEnd:
+	// Convert from &src[ret] to ret.
+	SUBQ DX, SI
+	MOVQ SI, ret+40(FP)
+	RET
+
+// ----------------------------------------------------------------------------
+
+// func encodeBlock(dst, src []byte) (d int)
+//
+// All local variables fit into registers, other than "var table". The register
+// allocation:
+//	- AX	.	.
+//	- BX	.	.
+//	- CX	56	shift (note that amd64 shifts by non-immediates must use CX).
+//	- DX	64	&src[0], tableSize
+//	- SI	72	&src[s]
+//	- DI	80	&dst[d]
+//	- R9	88	sLimit
+//	- R10	.	&src[nextEmit]
+//	- R11	96	prevHash, currHash, nextHash, offset
+//	- R12	104	&src[base], skip
+//	- R13	.	&src[nextS], &src[len(src) - 8]
+//	- R14	.	len(src), bytesBetweenHashLookups, &src[len(src)], x
+//	- R15	112	candidate
+//
+// The second column (56, 64, etc) is the stack offset to spill the registers
+// when calling other functions. We could pack this slightly tighter, but it's
+// simpler to have a dedicated spill map independent of the function called.
+//
+// "var table [maxTableSize]uint16" takes up 32768 bytes of stack space. An
+// extra 56 bytes, to call other functions, and an extra 64 bytes, to spill
+// local variables (registers) during calls gives 32768 + 56 + 64 = 32888.
+TEXT ·encodeBlock(SB), 0, $32888-56
+	MOVQ dst_base+0(FP), DI
+	MOVQ src_base+24(FP), SI
+	MOVQ src_len+32(FP), R14
+
+	// shift, tableSize := uint32(32-8), 1<<8
+	MOVQ $24, CX
+	MOVQ $256, DX
+
+calcShift:
+	// for ; tableSize < maxTableSize && tableSize < len(src); tableSize *= 2 {
+	//	shift--
+	// }
+	CMPQ DX, $16384
+	JGE  varTable
+	CMPQ DX, R14
+	JGE  varTable
+	SUBQ $1, CX
+	SHLQ $1, DX
+	JMP  calcShift
+
+varTable:
+	// var table [maxTableSize]uint16
+	//
+	// In the asm code, unlike the Go code, we can zero-initialize only the
+	// first tableSize elements. Each uint16 element is 2 bytes and each MOVOU
+	// writes 16 bytes, so we can do only tableSize/8 writes instead of the
+	// 2048 writes that would zero-initialize all of table's 32768 bytes.
+	SHRQ $3, DX
+	LEAQ table-32768(SP), BX
+	PXOR X0, X0
+
+memclr:
+	MOVOU X0, 0(BX)
+	ADDQ  $16, BX
+	SUBQ  $1, DX
+	JNZ   memclr
+
+	// !!! DX = &src[0]
+	MOVQ SI, DX
+
+	// sLimit := len(src) - inputMargin
+	MOVQ R14, R9
+	SUBQ $15, R9
+
+	// !!! Pre-emptively spill CX, DX and R9 to the stack. Their values don't
+	// change for the rest of the function.
+	MOVQ CX, 56(SP)
+	MOVQ DX, 64(SP)
+	MOVQ R9, 88(SP)
+
+	// nextEmit := 0
+	MOVQ DX, R10
+
+	// s := 1
+	ADDQ $1, SI
+
+	// nextHash := hash(load32(src, s), shift)
+	MOVL  0(SI), R11
+	IMULL $0x1e35a7bd, R11
+	SHRL  CX, R11
+
+outer:
+	// for { etc }
+
+	// skip := 32
+	MOVQ $32, R12
+
+	// nextS := s
+	MOVQ SI, R13
+
+	// candidate := 0
+	MOVQ $0, R15
+
+inner0:
+	// for { etc }
+
+	// s := nextS
+	MOVQ R13, SI
+
+	// bytesBetweenHashLookups := skip >> 5
+	MOVQ R12, R14
+	SHRQ $5, R14
+
+	// nextS = s + bytesBetweenHashLookups
+	ADDQ R14, R13
+
+	// skip += bytesBetweenHashLookups
+	ADDQ R14, R12
+
+	// if nextS > sLimit { goto emitRemainder }
+	MOVQ R13, AX
+	SUBQ DX, AX
+	CMPQ AX, R9
+	JA   emitRemainder
+
+	// candidate = int(table[nextHash])
+	// XXX: MOVWQZX table-32768(SP)(R11*2), R15
+	// XXX: 4e 0f b7 7c 5c 78       movzwq 0x78(%rsp,%r11,2),%r15
+	BYTE $0x4e
+	BYTE $0x0f
+	BYTE $0xb7
+	BYTE $0x7c
+	BYTE $0x5c
+	BYTE $0x78
+
+	// table[nextHash] = uint16(s)
+	MOVQ SI, AX
+	SUBQ DX, AX
+
+	// XXX: MOVW AX, table-32768(SP)(R11*2)
+	// XXX: 66 42 89 44 5c 78       mov    %ax,0x78(%rsp,%r11,2)
+	BYTE $0x66
+	BYTE $0x42
+	BYTE $0x89
+	BYTE $0x44
+	BYTE $0x5c
+	BYTE $0x78
+
+	// nextHash = hash(load32(src, nextS), shift)
+	MOVL  0(R13), R11
+	IMULL $0x1e35a7bd, R11
+	SHRL  CX, R11
+
+	// if load32(src, s) != load32(src, candidate) { continue } break
+	MOVL 0(SI), AX
+	MOVL (DX)(R15*1), BX
+	CMPL AX, BX
+	JNE  inner0
+
+fourByteMatch:
+	// As per the encode_other.go code:
+	//
+	// A 4-byte match has been found. We'll later see etc.
+
+	// !!! Jump to a fast path for short (<= 16 byte) literals. See the comment
+	// on inputMargin in encode.go.
+	MOVQ SI, AX
+	SUBQ R10, AX
+	CMPQ AX, $16
+	JLE  emitLiteralFastPath
+
+	// ----------------------------------------
+	// Begin inline of the emitLiteral call.
+	//
+	// d += emitLiteral(dst[d:], src[nextEmit:s])
+
+	MOVL AX, BX
+	SUBL $1, BX
+
+	CMPL BX, $60
+	JLT  inlineEmitLiteralOneByte
+	CMPL BX, $256
+	JLT  inlineEmitLiteralTwoBytes
+
+inlineEmitLiteralThreeBytes:
+	MOVB $0xf4, 0(DI)
+	MOVW BX, 1(DI)
+	ADDQ $3, DI
+	JMP  inlineEmitLiteralMemmove
+
+inlineEmitLiteralTwoBytes:
+	MOVB $0xf0, 0(DI)
+	MOVB BX, 1(DI)
+	ADDQ $2, DI
+	JMP  inlineEmitLiteralMemmove
+
+inlineEmitLiteralOneByte:
+	SHLB $2, BX
+	MOVB BX, 0(DI)
+	ADDQ $1, DI
+
+inlineEmitLiteralMemmove:
+	// Spill local variables (registers) onto the stack; call; unspill.
+	//
+	// copy(dst[i:], lit)
+	//
+	// This means calling runtime·memmove(&dst[i], &lit[0], len(lit)), so we push
+	// DI, R10 and AX as arguments.
+	MOVQ DI, 0(SP)
+	MOVQ R10, 8(SP)
+	MOVQ AX, 16(SP)
+	ADDQ AX, DI              // Finish the "d +=" part of "d += emitLiteral(etc)".
+	MOVQ SI, 72(SP)
+	MOVQ DI, 80(SP)
+	MOVQ R15, 112(SP)
+	CALL runtime·memmove(SB)
+	MOVQ 56(SP), CX
+	MOVQ 64(SP), DX
+	MOVQ 72(SP), SI
+	MOVQ 80(SP), DI
+	MOVQ 88(SP), R9
+	MOVQ 112(SP), R15
+	JMP  inner1
+
+inlineEmitLiteralEnd:
+	// End inline of the emitLiteral call.
+	// ----------------------------------------
+
+emitLiteralFastPath:
+	// !!! Emit the 1-byte encoding "uint8(len(lit)-1)<<2".
+	MOVB AX, BX
+	SUBB $1, BX
+	SHLB $2, BX
+	MOVB BX, (DI)
+	ADDQ $1, DI
+
+	// !!! Implement the copy from lit to dst as a 16-byte load and store.
+	// (Encode's documentation says that dst and src must not overlap.)
+	//
+	// This always copies 16 bytes, instead of only len(lit) bytes, but that's
+	// OK. Subsequent iterations will fix up the overrun.
+	//
+	// Note that on amd64, it is legal and cheap to issue unaligned 8-byte or
+	// 16-byte loads and stores. This technique probably wouldn't be as
+	// effective on architectures that are fussier about alignment.
+	MOVOU 0(R10), X0
+	MOVOU X0, 0(DI)
+	ADDQ  AX, DI
+
+inner1:
+	// for { etc }
+
+	// base := s
+	MOVQ SI, R12
+
+	// !!! offset := base - candidate
+	MOVQ R12, R11
+	SUBQ R15, R11
+	SUBQ DX, R11
+
+	// ----------------------------------------
+	// Begin inline of the extendMatch call.
+	//
+	// s = extendMatch(src, candidate+4, s+4)
+
+	// !!! R14 = &src[len(src)]
+	MOVQ src_len+32(FP), R14
+	ADDQ DX, R14
+
+	// !!! R13 = &src[len(src) - 8]
+	MOVQ R14, R13
+	SUBQ $8, R13
+
+	// !!! R15 = &src[candidate + 4]
+	ADDQ $4, R15
+	ADDQ DX, R15
+
+	// !!! s += 4
+	ADDQ $4, SI
+
+inlineExtendMatchCmp8:
+	// As long as we are 8 or more bytes before the end of src, we can load and
+	// compare 8 bytes at a time. If those 8 bytes are equal, repeat.
+	CMPQ SI, R13
+	JA   inlineExtendMatchCmp1
+	MOVQ (R15), AX
+	MOVQ (SI), BX
+	CMPQ AX, BX
+	JNE  inlineExtendMatchBSF
+	ADDQ $8, R15
+	ADDQ $8, SI
+	JMP  inlineExtendMatchCmp8
+
+inlineExtendMatchBSF:
+	// If those 8 bytes were not equal, XOR the two 8 byte values, and return
+	// the index of the first byte that differs. The BSF instruction finds the
+	// least significant 1 bit, the amd64 architecture is little-endian, and
+	// the shift by 3 converts a bit index to a byte index.
+	XORQ AX, BX
+	BSFQ BX, BX
+	SHRQ $3, BX
+	ADDQ BX, SI
+	JMP  inlineExtendMatchEnd
+
+inlineExtendMatchCmp1:
+	// In src's tail, compare 1 byte at a time.
+	CMPQ SI, R14
+	JAE  inlineExtendMatchEnd
+	MOVB (R15), AX
+	MOVB (SI), BX
+	CMPB AX, BX
+	JNE  inlineExtendMatchEnd
+	ADDQ $1, R15
+	ADDQ $1, SI
+	JMP  inlineExtendMatchCmp1
+
+inlineExtendMatchEnd:
+	// End inline of the extendMatch call.
+	// ----------------------------------------
+
+	// ----------------------------------------
+	// Begin inline of the emitCopy call.
+	//
+	// d += emitCopy(dst[d:], base-candidate, s-base)
+
+	// !!! length := s - base
+	MOVQ SI, AX
+	SUBQ R12, AX
+
+inlineEmitCopyLoop0:
+	// for length >= 68 { etc }
+	CMPL AX, $68
+	JLT  inlineEmitCopyStep1
+
+	// Emit a length 64 copy, encoded as 3 bytes.
+	MOVB $0xfe, 0(DI)
+	MOVW R11, 1(DI)
+	ADDQ $3, DI
+	SUBL $64, AX
+	JMP  inlineEmitCopyLoop0
+
+inlineEmitCopyStep1:
+	// if length > 64 { etc }
+	CMPL AX, $64
+	JLE  inlineEmitCopyStep2
+
+	// Emit a length 60 copy, encoded as 3 bytes.
+	MOVB $0xee, 0(DI)
+	MOVW R11, 1(DI)
+	ADDQ $3, DI
+	SUBL $60, AX
+
+inlineEmitCopyStep2:
+	// if length >= 12 || offset >= 2048 { goto inlineEmitCopyStep3 }
+	CMPL AX, $12
+	JGE  inlineEmitCopyStep3
+	CMPL R11, $2048
+	JGE  inlineEmitCopyStep3
+
+	// Emit the remaining copy, encoded as 2 bytes.
+	MOVB R11, 1(DI)
+	SHRL $8, R11
+	SHLB $5, R11
+	SUBB $4, AX
+	SHLB $2, AX
+	ORB  AX, R11
+	ORB  $1, R11
+	MOVB R11, 0(DI)
+	ADDQ $2, DI
+	JMP  inlineEmitCopyEnd
+
+inlineEmitCopyStep3:
+	// Emit the remaining copy, encoded as 3 bytes.
+	SUBL $1, AX
+	SHLB $2, AX
+	ORB  $2, AX
+	MOVB AX, 0(DI)
+	MOVW R11, 1(DI)
+	ADDQ $3, DI
+
+inlineEmitCopyEnd:
+	// End inline of the emitCopy call.
+	// ----------------------------------------
+
+	// nextEmit = s
+	MOVQ SI, R10
+
+	// if s >= sLimit { goto emitRemainder }
+	MOVQ SI, AX
+	SUBQ DX, AX
+	CMPQ AX, R9
+	JAE  emitRemainder
+
+	// As per the encode_other.go code:
+	//
+	// We could immediately etc.
+
+	// x := load64(src, s-1)
+	MOVQ -1(SI), R14
+
+	// prevHash := hash(uint32(x>>0), shift)
+	MOVL  R14, R11
+	IMULL $0x1e35a7bd, R11
+	SHRL  CX, R11
+
+	// table[prevHash] = uint16(s-1)
+	MOVQ SI, AX
+	SUBQ DX, AX
+	SUBQ $1, AX
+
+	// XXX: MOVW AX, table-32768(SP)(R11*2)
+	// XXX: 66 42 89 44 5c 78       mov    %ax,0x78(%rsp,%r11,2)
+	BYTE $0x66
+	BYTE $0x42
+	BYTE $0x89
+	BYTE $0x44
+	BYTE $0x5c
+	BYTE $0x78
+
+	// currHash := hash(uint32(x>>8), shift)
+	SHRQ  $8, R14
+	MOVL  R14, R11
+	IMULL $0x1e35a7bd, R11
+	SHRL  CX, R11
+
+	// candidate = int(table[currHash])
+	// XXX: MOVWQZX table-32768(SP)(R11*2), R15
+	// XXX: 4e 0f b7 7c 5c 78       movzwq 0x78(%rsp,%r11,2),%r15
+	BYTE $0x4e
+	BYTE $0x0f
+	BYTE $0xb7
+	BYTE $0x7c
+	BYTE $0x5c
+	BYTE $0x78
+
+	// table[currHash] = uint16(s)
+	ADDQ $1, AX
+
+	// XXX: MOVW AX, table-32768(SP)(R11*2)
+	// XXX: 66 42 89 44 5c 78       mov    %ax,0x78(%rsp,%r11,2)
+	BYTE $0x66
+	BYTE $0x42
+	BYTE $0x89
+	BYTE $0x44
+	BYTE $0x5c
+	BYTE $0x78
+
+	// if uint32(x>>8) == load32(src, candidate) { continue }
+	MOVL (DX)(R15*1), BX
+	CMPL R14, BX
+	JEQ  inner1
+
+	// nextHash = hash(uint32(x>>16), shift)
+	SHRQ  $8, R14
+	MOVL  R14, R11
+	IMULL $0x1e35a7bd, R11
+	SHRL  CX, R11
+
+	// s++
+	ADDQ $1, SI
+
+	// break out of the inner1 for loop, i.e. continue the outer loop.
+	JMP outer
+
+emitRemainder:
+	// if nextEmit < len(src) { etc }
+	MOVQ src_len+32(FP), AX
+	ADDQ DX, AX
+	CMPQ R10, AX
+	JEQ  encodeBlockEnd
+
+	// d += emitLiteral(dst[d:], src[nextEmit:])
+	//
+	// Push args.
+	MOVQ DI, 0(SP)
+	MOVQ $0, 8(SP)   // Unnecessary, as the callee ignores it, but conservative.
+	MOVQ $0, 16(SP)  // Unnecessary, as the callee ignores it, but conservative.
+	MOVQ R10, 24(SP)
+	SUBQ R10, AX
+	MOVQ AX, 32(SP)
+	MOVQ AX, 40(SP)  // Unnecessary, as the callee ignores it, but conservative.
+
+	// Spill local variables (registers) onto the stack; call; unspill.
+	MOVQ DI, 80(SP)
+	CALL ·emitLiteral(SB)
+	MOVQ 80(SP), DI
+
+	// Finish the "d +=" part of "d += emitLiteral(etc)".
+	ADDQ 48(SP), DI
+
+encodeBlockEnd:
+	MOVQ dst_base+0(FP), AX
+	SUBQ AX, DI
+	MOVQ DI, d+48(FP)
+	RET

vendor/github.com/golang/snappy/encode_other.go

@@ -0,0 +1,238 @@
+// Copyright 2016 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !amd64 appengine !gc noasm
+
+package snappy
+
+func load32(b []byte, i int) uint32 {
+	b = b[i : i+4 : len(b)] // Help the compiler eliminate bounds checks on the next line.
+	return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
+}
+
+func load64(b []byte, i int) uint64 {
+	b = b[i : i+8 : len(b)] // Help the compiler eliminate bounds checks on the next line.
+	return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
+		uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
+}
+
+// emitLiteral writes a literal chunk and returns the number of bytes written.
+//
+// It assumes that:
+//	dst is long enough to hold the encoded bytes
+//	1 <= len(lit) && len(lit) <= 65536
+func emitLiteral(dst, lit []byte) int {
+	i, n := 0, uint(len(lit)-1)
+	switch {
+	case n < 60:
+		dst[0] = uint8(n)<<2 | tagLiteral
+		i = 1
+	case n < 1<<8:
+		dst[0] = 60<<2 | tagLiteral
+		dst[1] = uint8(n)
+		i = 2
+	default:
+		dst[0] = 61<<2 | tagLiteral
+		dst[1] = uint8(n)
+		dst[2] = uint8(n >> 8)
+		i = 3
+	}
+	return i + copy(dst[i:], lit)
+}
+
+// emitCopy writes a copy chunk and returns the number of bytes written.
+//
+// It assumes that:
+//	dst is long enough to hold the encoded bytes
+//	1 <= offset && offset <= 65535
+//	4 <= length && length <= 65535
+func emitCopy(dst []byte, offset, length int) int {
+	i := 0
+	// The maximum length for a single tagCopy1 or tagCopy2 op is 64 bytes. The
+	// threshold for this loop is a little higher (at 68 = 64 + 4), and the
+	// length emitted down below is is a little lower (at 60 = 64 - 4), because
+	// it's shorter to encode a length 67 copy as a length 60 tagCopy2 followed
+	// by a length 7 tagCopy1 (which encodes as 3+2 bytes) than to encode it as
+	// a length 64 tagCopy2 followed by a length 3 tagCopy2 (which encodes as
+	// 3+3 bytes). The magic 4 in the 64±4 is because the minimum length for a
+	// tagCopy1 op is 4 bytes, which is why a length 3 copy has to be an
+	// encodes-as-3-bytes tagCopy2 instead of an encodes-as-2-bytes tagCopy1.
+	for length >= 68 {
+		// Emit a length 64 copy, encoded as 3 bytes.
+		dst[i+0] = 63<<2 | tagCopy2
+		dst[i+1] = uint8(offset)
+		dst[i+2] = uint8(offset >> 8)
+		i += 3
+		length -= 64
+	}
+	if length > 64 {
+		// Emit a length 60 copy, encoded as 3 bytes.
+		dst[i+0] = 59<<2 | tagCopy2
+		dst[i+1] = uint8(offset)
+		dst[i+2] = uint8(offset >> 8)
+		i += 3
+		length -= 60
+	}
+	if length >= 12 || offset >= 2048 {
+		// Emit the remaining copy, encoded as 3 bytes.
+		dst[i+0] = uint8(length-1)<<2 | tagCopy2
+		dst[i+1] = uint8(offset)
+		dst[i+2] = uint8(offset >> 8)
+		return i + 3
+	}
+	// Emit the remaining copy, encoded as 2 bytes.
+	dst[i+0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
+	dst[i+1] = uint8(offset)
+	return i + 2
+}
+
+// extendMatch returns the largest k such that k <= len(src) and that
+// src[i:i+k-j] and src[j:k] have the same contents.
+//
+// It assumes that:
+//	0 <= i && i < j && j <= len(src)
+func extendMatch(src []byte, i, j int) int {
+	for ; j < len(src) && src[i] == src[j]; i, j = i+1, j+1 {
+	}
+	return j
+}
+
+func hash(u, shift uint32) uint32 {
+	return (u * 0x1e35a7bd) >> shift
+}
+
+// encodeBlock encodes a non-empty src to a guaranteed-large-enough dst. It
+// assumes that the varint-encoded length of the decompressed bytes has already
+// been written.
+//
+// It also assumes that:
+//	len(dst) >= MaxEncodedLen(len(src)) &&
+// 	minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
+func encodeBlock(dst, src []byte) (d int) {
+	// Initialize the hash table. Its size ranges from 1<<8 to 1<<14 inclusive.
+	// The table element type is uint16, as s < sLimit and sLimit < len(src)
+	// and len(src) <= maxBlockSize and maxBlockSize == 65536.
+	const (
+		maxTableSize = 1 << 14
+		// tableMask is redundant, but helps the compiler eliminate bounds
+		// checks.
+		tableMask = maxTableSize - 1
+	)
+	shift := uint32(32 - 8)
+	for tableSize := 1 << 8; tableSize < maxTableSize && tableSize < len(src); tableSize *= 2 {
+		shift--
+	}
+	// In Go, all array elements are zero-initialized, so there is no advantage
+	// to a smaller tableSize per se. However, it matches the C++ algorithm,
+	// and in the asm versions of this code, we can get away with zeroing only
+	// the first tableSize elements.
+	var table [maxTableSize]uint16
+
+	// sLimit is when to stop looking for offset/length copies. The inputMargin
+	// lets us use a fast path for emitLiteral in the main loop, while we are
+	// looking for copies.
+	sLimit := len(src) - inputMargin
+
+	// nextEmit is where in src the next emitLiteral should start from.
+	nextEmit := 0
+
+	// The encoded form must start with a literal, as there are no previous
+	// bytes to copy, so we start looking for hash matches at s == 1.
+	s := 1
+	nextHash := hash(load32(src, s), shift)
+
+	for {
+		// Copied from the C++ snappy implementation:
+		//
+		// Heuristic match skipping: If 32 bytes are scanned with no matches
+		// found, start looking only at every other byte. If 32 more bytes are
+		// scanned (or skipped), look at every third byte, etc.. When a match
+		// is found, immediately go back to looking at every byte. This is a
+		// small loss (~5% performance, ~0.1% density) for compressible data
+		// due to more bookkeeping, but for non-compressible data (such as
+		// JPEG) it's a huge win since the compressor quickly "realizes" the
+		// data is incompressible and doesn't bother looking for matches
+		// everywhere.
+		//
+		// The "skip" variable keeps track of how many bytes there are since
+		// the last match; dividing it by 32 (ie. right-shifting by five) gives
+		// the number of bytes to move ahead for each iteration.
+		skip := 32
+
+		nextS := s
+		candidate := 0
+		for {
+			s = nextS
+			bytesBetweenHashLookups := skip >> 5
+			nextS = s + bytesBetweenHashLookups
+			skip += bytesBetweenHashLookups
+			if nextS > sLimit {
+				goto emitRemainder
+			}
+			candidate = int(table[nextHash&tableMask])
+			table[nextHash&tableMask] = uint16(s)
+			nextHash = hash(load32(src, nextS), shift)
+			if load32(src, s) == load32(src, candidate) {
+				break
+			}
+		}
+
+		// A 4-byte match has been found. We'll later see if more than 4 bytes
+		// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
+		// them as literal bytes.
+		d += emitLiteral(dst[d:], src[nextEmit:s])
+
+		// Call emitCopy, and then see if another emitCopy could be our next
+		// move. Repeat until we find no match for the input immediately after
+		// what was consumed by the last emitCopy call.
+		//
+		// If we exit this loop normally then we need to call emitLiteral next,
+		// though we don't yet know how big the literal will be. We handle that
+		// by proceeding to the next iteration of the main loop. We also can
+		// exit this loop via goto if we get close to exhausting the input.
+		for {
+			// Invariant: we have a 4-byte match at s, and no need to emit any
+			// literal bytes prior to s.
+			base := s
+
+			// Extend the 4-byte match as long as possible.
+			//
+			// This is an inlined version of:
+			//	s = extendMatch(src, candidate+4, s+4)
+			s += 4
+			for i := candidate + 4; s < len(src) && src[i] == src[s]; i, s = i+1, s+1 {
+			}
+
+			d += emitCopy(dst[d:], base-candidate, s-base)
+			nextEmit = s
+			if s >= sLimit {
+				goto emitRemainder
+			}
+
+			// We could immediately start working at s now, but to improve
+			// compression we first update the hash table at s-1 and at s. If
+			// another emitCopy is not our next move, also calculate nextHash
+			// at s+1. At least on GOARCH=amd64, these three hash calculations
+			// are faster as one load64 call (with some shifts) instead of
+			// three load32 calls.
+			x := load64(src, s-1)
+			prevHash := hash(uint32(x>>0), shift)
+			table[prevHash&tableMask] = uint16(s - 1)
+			currHash := hash(uint32(x>>8), shift)
+			candidate = int(table[currHash&tableMask])
+			table[currHash&tableMask] = uint16(s)
+			if uint32(x>>8) != load32(src, candidate) {
+				nextHash = hash(uint32(x>>16), shift)
+				s++
+				break
+			}
+		}
+	}
+
+emitRemainder:
+	if nextEmit < len(src) {
+		d += emitLiteral(dst[d:], src[nextEmit:])
+	}
+	return d
+}

vendor/github.com/golang/snappy/snappy.go

@@ -0,0 +1,87 @@
+// Copyright 2011 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package snappy implements the snappy block-based compression format.
+// It aims for very high speeds and reasonable compression.
+//
+// The C++ snappy implementation is at https://github.com/google/snappy
+package snappy
+
+import (
+	"hash/crc32"
+)
+
+/*
+Each encoded block begins with the varint-encoded length of the decoded data,
+followed by a sequence of chunks. Chunks begin and end on byte boundaries. The
+first byte of each chunk is broken into its 2 least and 6 most significant bits
+called l and m: l ranges in [0, 4) and m ranges in [0, 64). l is the chunk tag.
+Zero means a literal tag. All other values mean a copy tag.
+
+For literal tags:
+  - If m < 60, the next 1 + m bytes are literal bytes.
+  - Otherwise, let n be the little-endian unsigned integer denoted by the next
+    m - 59 bytes. The next 1 + n bytes after that are literal bytes.
+
+For copy tags, length bytes are copied from offset bytes ago, in the style of
+Lempel-Ziv compression algorithms. In particular:
+  - For l == 1, the offset ranges in [0, 1<<11) and the length in [4, 12).
+    The length is 4 + the low 3 bits of m. The high 3 bits of m form bits 8-10
+    of the offset. The next byte is bits 0-7 of the offset.
+  - For l == 2, the offset ranges in [0, 1<<16) and the length in [1, 65).
+    The length is 1 + m. The offset is the little-endian unsigned integer
+    denoted by the next 2 bytes.
+  - For l == 3, this tag is a legacy format that is no longer issued by most
+    encoders. Nonetheless, the offset ranges in [0, 1<<32) and the length in
+    [1, 65). The length is 1 + m. The offset is the little-endian unsigned
+    integer denoted by the next 4 bytes.
+*/
+const (
+	tagLiteral = 0x00
+	tagCopy1   = 0x01
+	tagCopy2   = 0x02
+	tagCopy4   = 0x03
+)
+
+const (
+	checksumSize    = 4
+	chunkHeaderSize = 4
+	magicChunk      = "\xff\x06\x00\x00" + magicBody
+	magicBody       = "sNaPpY"
+
+	// maxBlockSize is the maximum size of the input to encodeBlock. It is not
+	// part of the wire format per se, but some parts of the encoder assume
+	// that an offset fits into a uint16.
+	//
+	// Also, for the framing format (Writer type instead of Encode function),
+	// https://github.com/google/snappy/blob/master/framing_format.txt says
+	// that "the uncompressed data in a chunk must be no longer than 65536
+	// bytes".
+	maxBlockSize = 65536
+
+	// maxEncodedLenOfMaxBlockSize equals MaxEncodedLen(maxBlockSize), but is
+	// hard coded to be a const instead of a variable, so that obufLen can also
+	// be a const. Their equivalence is confirmed by
+	// TestMaxEncodedLenOfMaxBlockSize.
+	maxEncodedLenOfMaxBlockSize = 76490
+
+	obufHeaderLen = len(magicChunk) + checksumSize + chunkHeaderSize
+	obufLen       = obufHeaderLen + maxEncodedLenOfMaxBlockSize
+)
+
+const (
+	chunkTypeCompressedData   = 0x00
+	chunkTypeUncompressedData = 0x01
+	chunkTypePadding          = 0xfe
+	chunkTypeStreamIdentifier = 0xff
+)
+
+var crcTable = crc32.MakeTable(crc32.Castagnoli)
+
+// crc implements the checksum specified in section 3 of
+// https://github.com/google/snappy/blob/master/framing_format.txt
+func crc(b []byte) uint32 {
+	c := crc32.Update(0, crcTable, b)
+	return uint32(c>>15|c<<17) + 0xa282ead8
+}

vendor/github.com/pkg/errors/LICENSE

@@ -0,0 +1,23 @@
+Copyright (c) 2015, Dave Cheney <dave@cheney.net>
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/pkg/errors/README.md

@@ -0,0 +1,52 @@
+# errors [![Travis-CI](https://travis-ci.org/pkg/errors.svg)](https://travis-ci.org/pkg/errors) [![AppVeyor](https://ci.appveyor.com/api/projects/status/b98mptawhudj53ep/branch/master?svg=true)](https://ci.appveyor.com/project/davecheney/errors/branch/master) [![GoDoc](https://godoc.org/github.com/pkg/errors?status.svg)](http://godoc.org/github.com/pkg/errors) [![Report card](https://goreportcard.com/badge/github.com/pkg/errors)](https://goreportcard.com/report/github.com/pkg/errors)
+
+Package errors provides simple error handling primitives.
+
+`go get github.com/pkg/errors`
+
+The traditional error handling idiom in Go is roughly akin to
+```go
+if err != nil {
+        return err
+}
+```
+which applied recursively up the call stack results in error reports without context or debugging information. The errors package allows programmers to add context to the failure path in their code in a way that does not destroy the original value of the error.
+
+## Adding context to an error
+
+The errors.Wrap function returns a new error that adds context to the original error. For example
+```go
+_, err := ioutil.ReadAll(r)
+if err != nil {
+        return errors.Wrap(err, "read failed")
+}
+```
+## Retrieving the cause of an error
+
+Using `errors.Wrap` constructs a stack of errors, adding context to the preceding error. Depending on the nature of the error it may be necessary to reverse the operation of errors.Wrap to retrieve the original error for inspection. Any error value which implements this interface can be inspected by `errors.Cause`.
+```go
+type causer interface {
+        Cause() error
+}
+```
+`errors.Cause` will recursively retrieve the topmost error which does not implement `causer`, which is assumed to be the original cause. For example:
+```go
+switch err := errors.Cause(err).(type) {
+case *MyError:
+        // handle specifically
+default:
+        // unknown error
+}
+```
+
+[Read the package documentation for more information](https://godoc.org/github.com/pkg/errors).
+
+## Contributing
+
+We welcome pull requests, bug fixes and issue reports. With that said, the bar for adding new symbols to this package is intentionally set high.
+
+Before proposing a change, please discuss your change by raising an issue.
+
+## Licence
+
+BSD-2-Clause

vendor/github.com/pkg/errors/appveyor.yml

@@ -0,0 +1,32 @@
+version: build-{build}.{branch}
+
+clone_folder: C:\gopath\src\github.com\pkg\errors
+shallow_clone: true # for startup speed
+
+environment:
+  GOPATH: C:\gopath
+
+platform:
+  - x64
+
+# http://www.appveyor.com/docs/installed-software
+install:
+  # some helpful output for debugging builds
+  - go version
+  - go env
+  # pre-installed MinGW at C:\MinGW is 32bit only
+  # but MSYS2 at C:\msys64 has mingw64
+  - set PATH=C:\msys64\mingw64\bin;%PATH%
+  - gcc --version
+  - g++ --version
+
+build_script:
+  - go install -v ./...
+
+test_script:
+  - set PATH=C:\gopath\bin;%PATH%
+  - go test -v ./...
+
+#artifacts:
+#  - path: '%GOPATH%\bin\*.exe'
+deploy: off

vendor/github.com/pkg/errors/errors.go

@@ -0,0 +1,269 @@
+// Package errors provides simple error handling primitives.
+//
+// The traditional error handling idiom in Go is roughly akin to
+//
+//     if err != nil {
+//             return err
+//     }
+//
+// which applied recursively up the call stack results in error reports
+// without context or debugging information. The errors package allows
+// programmers to add context to the failure path in their code in a way
+// that does not destroy the original value of the error.
+//
+// Adding context to an error
+//
+// The errors.Wrap function returns a new error that adds context to the
+// original error by recording a stack trace at the point Wrap is called,
+// and the supplied message. For example
+//
+//     _, err := ioutil.ReadAll(r)
+//     if err != nil {
+//             return errors.Wrap(err, "read failed")
+//     }
+//
+// If additional control is required the errors.WithStack and errors.WithMessage
+// functions destructure errors.Wrap into its component operations of annotating
+// an error with a stack trace and an a message, respectively.
+//
+// Retrieving the cause of an error
+//
+// Using errors.Wrap constructs a stack of errors, adding context to the
+// preceding error. Depending on the nature of the error it may be necessary
+// to reverse the operation of errors.Wrap to retrieve the original error
+// for inspection. Any error value which implements this interface
+//
+//     type causer interface {
+//             Cause() error
+//     }
+//
+// can be inspected by errors.Cause. errors.Cause will recursively retrieve
+// the topmost error which does not implement causer, which is assumed to be
+// the original cause. For example:
+//
+//     switch err := errors.Cause(err).(type) {
+//     case *MyError:
+//             // handle specifically
+//     default:
+//             // unknown error
+//     }
+//
+// causer interface is not exported by this package, but is considered a part
+// of stable public API.
+//
+// Formatted printing of errors
+//
+// All error values returned from this package implement fmt.Formatter and can
+// be formatted by the fmt package. The following verbs are supported
+//
+//     %s    print the error. If the error has a Cause it will be
+//           printed recursively
+//     %v    see %s
+//     %+v   extended format. Each Frame of the error's StackTrace will
+//           be printed in detail.
+//
+// Retrieving the stack trace of an error or wrapper
+//
+// New, Errorf, Wrap, and Wrapf record a stack trace at the point they are
+// invoked. This information can be retrieved with the following interface.
+//
+//     type stackTracer interface {
+//             StackTrace() errors.StackTrace
+//     }
+//
+// Where errors.StackTrace is defined as
+//
+//     type StackTrace []Frame
+//
+// The Frame type represents a call site in the stack trace. Frame supports
+// the fmt.Formatter interface that can be used for printing information about
+// the stack trace of this error. For example:
+//
+//     if err, ok := err.(stackTracer); ok {
+//             for _, f := range err.StackTrace() {
+//                     fmt.Printf("%+s:%d", f)
+//             }
+//     }
+//
+// stackTracer interface is not exported by this package, but is considered a part
+// of stable public API.
+//
+// See the documentation for Frame.Format for more details.
+package errors
+
+import (
+	"fmt"
+	"io"
+)
+
+// New returns an error with the supplied message.
+// New also records the stack trace at the point it was called.
+func New(message string) error {
+	return &fundamental{
+		msg:   message,
+		stack: callers(),
+	}
+}
+
+// Errorf formats according to a format specifier and returns the string
+// as a value that satisfies error.
+// Errorf also records the stack trace at the point it was called.
+func Errorf(format string, args ...interface{}) error {
+	return &fundamental{
+		msg:   fmt.Sprintf(format, args...),
+		stack: callers(),
+	}
+}
+
+// fundamental is an error that has a message and a stack, but no caller.
+type fundamental struct {
+	msg string
+	*stack
+}
+
+func (f *fundamental) Error() string { return f.msg }
+
+func (f *fundamental) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			io.WriteString(s, f.msg)
+			f.stack.Format(s, verb)
+			return
+		}
+		fallthrough
+	case 's':
+		io.WriteString(s, f.msg)
+	case 'q':
+		fmt.Fprintf(s, "%q", f.msg)
+	}
+}
+
+// WithStack annotates err with a stack trace at the point WithStack was called.
+// If err is nil, WithStack returns nil.
+func WithStack(err error) error {
+	if err == nil {
+		return nil
+	}
+	return &withStack{
+		err,
+		callers(),
+	}
+}
+
+type withStack struct {
+	error
+	*stack
+}
+
+func (w *withStack) Cause() error { return w.error }
+
+func (w *withStack) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			fmt.Fprintf(s, "%+v", w.Cause())
+			w.stack.Format(s, verb)
+			return
+		}
+		fallthrough
+	case 's':
+		io.WriteString(s, w.Error())
+	case 'q':
+		fmt.Fprintf(s, "%q", w.Error())
+	}
+}
+
+// Wrap returns an error annotating err with a stack trace
+// at the point Wrap is called, and the supplied message.
+// If err is nil, Wrap returns nil.
+func Wrap(err error, message string) error {
+	if err == nil {
+		return nil
+	}
+	err = &withMessage{
+		cause: err,
+		msg:   message,
+	}
+	return &withStack{
+		err,
+		callers(),
+	}
+}
+
+// Wrapf returns an error annotating err with a stack trace
+// at the point Wrapf is call, and the format specifier.
+// If err is nil, Wrapf returns nil.
+func Wrapf(err error, format string, args ...interface{}) error {
+	if err == nil {
+		return nil
+	}
+	err = &withMessage{
+		cause: err,
+		msg:   fmt.Sprintf(format, args...),
+	}
+	return &withStack{
+		err,
+		callers(),
+	}
+}
+
+// WithMessage annotates err with a new message.
+// If err is nil, WithMessage returns nil.
+func WithMessage(err error, message string) error {
+	if err == nil {
+		return nil
+	}
+	return &withMessage{
+		cause: err,
+		msg:   message,
+	}
+}
+
+type withMessage struct {
+	cause error
+	msg   string
+}
+
+func (w *withMessage) Error() string { return w.msg + ": " + w.cause.Error() }
+func (w *withMessage) Cause() error  { return w.cause }
+
+func (w *withMessage) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			fmt.Fprintf(s, "%+v\n", w.Cause())
+			io.WriteString(s, w.msg)
+			return
+		}
+		fallthrough
+	case 's', 'q':
+		io.WriteString(s, w.Error())
+	}
+}
+
+// Cause returns the underlying cause of the error, if possible.
+// An error value has a cause if it implements the following
+// interface:
+//
+//     type causer interface {
+//            Cause() error
+//     }
+//
+// If the error does not implement Cause, the original error will
+// be returned. If the error is nil, nil will be returned without further
+// investigation.
+func Cause(err error) error {
+	type causer interface {
+		Cause() error
+	}
+
+	for err != nil {
+		cause, ok := err.(causer)
+		if !ok {
+			break
+		}
+		err = cause.Cause()
+	}
+	return err
+}

vendor/github.com/pkg/errors/stack.go

@@ -0,0 +1,186 @@
+package errors
+
+import (
+	"fmt"
+	"io"
+	"path"
+	"runtime"
+	"strings"
+)
+
+// Frame represents a program counter inside a stack frame.
+type Frame uintptr
+
+// pc returns the program counter for this frame;
+// multiple frames may have the same PC value.
+func (f Frame) pc() uintptr { return uintptr(f) - 1 }
+
+// file returns the full path to the file that contains the
+// function for this Frame's pc.
+func (f Frame) file() string {
+	fn := runtime.FuncForPC(f.pc())
+	if fn == nil {
+		return "unknown"
+	}
+	file, _ := fn.FileLine(f.pc())
+	return file
+}
+
+// line returns the line number of source code of the
+// function for this Frame's pc.
+func (f Frame) line() int {
+	fn := runtime.FuncForPC(f.pc())
+	if fn == nil {
+		return 0
+	}
+	_, line := fn.FileLine(f.pc())
+	return line
+}
+
+// Format formats the frame according to the fmt.Formatter interface.
+//
+//    %s    source file
+//    %d    source line
+//    %n    function name
+//    %v    equivalent to %s:%d
+//
+// Format accepts flags that alter the printing of some verbs, as follows:
+//
+//    %+s   path of source file relative to the compile time GOPATH
+//    %+v   equivalent to %+s:%d
+func (f Frame) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 's':
+		switch {
+		case s.Flag('+'):
+			pc := f.pc()
+			fn := runtime.FuncForPC(pc)
+			if fn == nil {
+				io.WriteString(s, "unknown")
+			} else {
+				file, _ := fn.FileLine(pc)
+				fmt.Fprintf(s, "%s\n\t%s", fn.Name(), file)
+			}
+		default:
+			io.WriteString(s, path.Base(f.file()))
+		}
+	case 'd':
+		fmt.Fprintf(s, "%d", f.line())
+	case 'n':
+		name := runtime.FuncForPC(f.pc()).Name()
+		io.WriteString(s, funcname(name))
+	case 'v':
+		f.Format(s, 's')
+		io.WriteString(s, ":")
+		f.Format(s, 'd')
+	}
+}
+
+// StackTrace is stack of Frames from innermost (newest) to outermost (oldest).
+type StackTrace []Frame
+
+// Format formats the stack of Frames according to the fmt.Formatter interface.
+//
+//    %s	lists source files for each Frame in the stack
+//    %v	lists the source file and line number for each Frame in the stack
+//
+// Format accepts flags that alter the printing of some verbs, as follows:
+//
+//    %+v   Prints filename, function, and line number for each Frame in the stack.
+func (st StackTrace) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		switch {
+		case s.Flag('+'):
+			for _, f := range st {
+				fmt.Fprintf(s, "\n%+v", f)
+			}
+		case s.Flag('#'):
+			fmt.Fprintf(s, "%#v", []Frame(st))
+		default:
+			fmt.Fprintf(s, "%v", []Frame(st))
+		}
+	case 's':
+		fmt.Fprintf(s, "%s", []Frame(st))
+	}
+}
+
+// stack represents a stack of program counters.
+type stack []uintptr
+
+func (s *stack) Format(st fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		switch {
+		case st.Flag('+'):
+			for _, pc := range *s {
+				f := Frame(pc)
+				fmt.Fprintf(st, "\n%+v", f)
+			}
+		}
+	}
+}
+
+func (s *stack) StackTrace() StackTrace {
+	f := make([]Frame, len(*s))
+	for i := 0; i < len(f); i++ {
+		f[i] = Frame((*s)[i])
+	}
+	return f
+}
+
+func callers() *stack {
+	const depth = 32
+	var pcs [depth]uintptr
+	n := runtime.Callers(3, pcs[:])
+	var st stack = pcs[0:n]
+	return &st
+}
+
+// funcname removes the path prefix component of a function's name reported by func.Name().
+func funcname(name string) string {
+	i := strings.LastIndex(name, "/")
+	name = name[i+1:]
+	i = strings.Index(name, ".")
+	return name[i+1:]
+}
+
+func trimGOPATH(name, file string) string {
+	// Here we want to get the source file path relative to the compile time
+	// GOPATH. As of Go 1.6.x there is no direct way to know the compiled
+	// GOPATH at runtime, but we can infer the number of path segments in the
+	// GOPATH. We note that fn.Name() returns the function name qualified by
+	// the import path, which does not include the GOPATH. Thus we can trim
+	// segments from the beginning of the file path until the number of path
+	// separators remaining is one more than the number of path separators in
+	// the function name. For example, given:
+	//
+	//    GOPATH     /home/user
+	//    file       /home/user/src/pkg/sub/file.go
+	//    fn.Name()  pkg/sub.Type.Method
+	//
+	// We want to produce:
+	//
+	//    pkg/sub/file.go
+	//
+	// From this we can easily see that fn.Name() has one less path separator
+	// than our desired output. We count separators from the end of the file
+	// path until it finds two more than in the function name and then move
+	// one character forward to preserve the initial path segment without a
+	// leading separator.
+	const sep = "/"
+	goal := strings.Count(name, sep) + 2
+	i := len(file)
+	for n := 0; n < goal; n++ {
+		i = strings.LastIndex(file[:i], sep)
+		if i == -1 {
+			// not enough separators found, set i so that the slice expression
+			// below leaves file unmodified
+			i = -len(sep)
+			break
+		}
+	}
+	// get back to 0 or trim the leading separator
+	file = file[i+len(sep):]
+	return file
+}

vendor/github.com/templexxx/cpufeat/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/templexxx/cpufeat/cpu.go

@@ -0,0 +1,32 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package cpu implements processor feature detection
+// used by the Go standard libary.
+package cpufeat
+
+var X86 x86
+
+// The booleans in x86 contain the correspondingly named cpuid feature bit.
+// HasAVX and HasAVX2 are only set if the OS does support XMM and YMM registers
+// in addition to the cpuid feature bit being set.
+// The struct is padded to avoid false sharing.
+type x86 struct {
+	_            [CacheLineSize]byte
+	HasAES       bool
+	HasAVX       bool
+	HasAVX2      bool
+	HasBMI1      bool
+	HasBMI2      bool
+	HasERMS      bool
+	HasOSXSAVE   bool
+	HasPCLMULQDQ bool
+	HasPOPCNT    bool
+	HasSSE2      bool
+	HasSSE3      bool
+	HasSSSE3     bool
+	HasSSE41     bool
+	HasSSE42     bool
+	_            [CacheLineSize]byte
+}

vendor/github.com/templexxx/cpufeat/cpu_arm.go

@@ -0,0 +1,7 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cpufeat
+
+const CacheLineSize = 32

vendor/github.com/templexxx/cpufeat/cpu_arm64.go

@@ -0,0 +1,7 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cpufeat
+
+const CacheLineSize = 32

vendor/github.com/templexxx/cpufeat/cpu_mips.go

@@ -0,0 +1,7 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cpufeat
+
+const CacheLineSize = 32

vendor/github.com/templexxx/cpufeat/cpu_mips64.go

@@ -0,0 +1,7 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cpufeat
+
+const CacheLineSize = 32

vendor/github.com/templexxx/cpufeat/cpu_mips64le.go

@@ -0,0 +1,7 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cpufeat
+
+const CacheLineSize = 32

vendor/github.com/templexxx/cpufeat/cpu_mipsle.go

@@ -0,0 +1,7 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cpufeat
+
+const CacheLineSize = 32

vendor/github.com/templexxx/cpufeat/cpu_ppc64.go

@@ -0,0 +1,7 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cpufeat
+
+const CacheLineSize = 128

vendor/github.com/templexxx/cpufeat/cpu_ppc64le.go

@@ -0,0 +1,7 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cpufeat
+
+const CacheLineSize = 128

vendor/github.com/templexxx/cpufeat/cpu_s390x.go

@@ -0,0 +1,7 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cpufeat
+
+const CacheLineSize = 256

vendor/github.com/templexxx/cpufeat/cpu_x86.go

@@ -0,0 +1,59 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build 386 amd64 amd64p32
+
+package cpufeat
+
+const CacheLineSize = 64
+
+// cpuid is implemented in cpu_x86.s.
+func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
+
+// xgetbv with ecx = 0 is implemented in cpu_x86.s.
+func xgetbv() (eax, edx uint32)
+
+func init() {
+	maxId, _, _, _ := cpuid(0, 0)
+
+	if maxId < 1 {
+		return
+	}
+
+	_, _, ecx1, edx1 := cpuid(1, 0)
+	X86.HasSSE2 = isSet(26, edx1)
+
+	X86.HasSSE3 = isSet(0, ecx1)
+	X86.HasPCLMULQDQ = isSet(1, ecx1)
+	X86.HasSSSE3 = isSet(9, ecx1)
+	X86.HasSSE41 = isSet(19, ecx1)
+	X86.HasSSE42 = isSet(20, ecx1)
+	X86.HasPOPCNT = isSet(23, ecx1)
+	X86.HasAES = isSet(25, ecx1)
+	X86.HasOSXSAVE = isSet(27, ecx1)
+
+	osSupportsAVX := false
+	// For XGETBV, OSXSAVE bit is required and sufficient.
+	if X86.HasOSXSAVE {
+		eax, _ := xgetbv()
+		// Check if XMM and YMM registers have OS support.
+		osSupportsAVX = isSet(1, eax) && isSet(2, eax)
+	}
+
+	X86.HasAVX = isSet(28, ecx1) && osSupportsAVX
+
+	if maxId < 7 {
+		return
+	}
+
+	_, ebx7, _, _ := cpuid(7, 0)
+	X86.HasBMI1 = isSet(3, ebx7)
+	X86.HasAVX2 = isSet(5, ebx7) && osSupportsAVX
+	X86.HasBMI2 = isSet(8, ebx7)
+	X86.HasERMS = isSet(9, ebx7)
+}
+
+func isSet(bitpos uint, value uint32) bool {
+	return value&(1<<bitpos) != 0
+}

vendor/github.com/templexxx/cpufeat/cpu_x86.s

@@ -0,0 +1,32 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build 386 amd64 amd64p32
+
+#include "textflag.h"
+
+// func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
+TEXT ·cpuid(SB), NOSPLIT, $0-24
+	MOVL eaxArg+0(FP), AX
+	MOVL ecxArg+4(FP), CX
+	CPUID
+	MOVL AX, eax+8(FP)
+	MOVL BX, ebx+12(FP)
+	MOVL CX, ecx+16(FP)
+	MOVL DX, edx+20(FP)
+	RET
+
+// func xgetbv() (eax, edx uint32)
+TEXT ·xgetbv(SB),NOSPLIT,$0-8
+#ifdef GOOS_nacl
+	// nacl does not support XGETBV.
+	MOVL $0, eax+0(FP)
+	MOVL $0, edx+4(FP)
+#else
+	MOVL $0, CX
+	WORD $0x010f; BYTE $0xd0 //XGETBV
+	MOVL AX, eax+0(FP)
+	MOVL DX, edx+4(FP)
+#endif
+	RET

vendor/github.com/templexxx/reedsolomon/LICENSE

@@ -0,0 +1,23 @@
+MIT License
+
+Copyright (c) 2017 Templexxx
+Copyright (c) 2015 Klaus Post
+Copyright (c) 2015 Backblaze
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/templexxx/reedsolomon/README.md

@@ -0,0 +1,109 @@
+# Reed-Solomon
+
+[![GoDoc][1]][2] [![MIT licensed][3]][4] [![Build Status][5]][6] [![Go Report Card][7]][8] 
+
+[1]: https://godoc.org/github.com/templexxx/reedsolomon?status.svg
+[2]: https://godoc.org/github.com/templexxx/reedsolomon
+[3]: https://img.shields.io/badge/license-MIT-blue.svg
+[4]: LICENSE
+[5]: https://travis-ci.org/templexxx/reedsolomon.svg?branch=master
+[6]: https://travis-ci.org/templexxx/reedsolomon
+[7]: https://goreportcard.com/badge/github.com/templexxx/reedsolomon
+[8]: https://goreportcard.com/report/github.com/templexxx/reedsolomon
+
+
+## Introduction:
+1.  Reed-Solomon Erasure Code engine in pure Go.
+2.  Super Fast: more than 10GB/s per physics core ( 10+4, 4KB per vector, Macbook Pro 2.8 GHz Intel Core i7 )
+
+## Installation
+To get the package use the standard:
+```bash
+go get github.com/templexxx/reedsolomon
+```
+
+## Documentation
+See the associated [GoDoc](http://godoc.org/github.com/templexxx/reedsolomon)
+
+## Specification
+### GOARCH
+1. All arch are supported
+2. 0.1.0 need go1.9 for sync.Map in AMD64
+
+### Math
+1. Coding over in GF(2^8)
+2. Primitive Polynomial: x^8 + x^4 + x^3 + x^2 + 1 (0x1d)
+3. mathtool/gentbls.go : generator Primitive Polynomial and it's log table, exp table, multiply table, inverse table etc. We can get more info about how galois field work
+4. mathtool/cntinverse.go : calculate how many inverse matrix will have in different RS codes config
+5. Both of Cauchy and Vandermonde Matrix are supported. Vandermonde need more operations for preserving the property that any square subset of rows is invertible
+
+### Why so fast?
+These three parts will cost too much time:
+
+1. lookup galois-field tables
+2. read/write memory
+3. calculate inverse matrix in the reconstruct process
+
+SIMD will solve no.1
+
+Cache-friendly codes will help to solve no.2 & no.3, and more, use a sync.Map for cache inverse matrix, it will help to save about 1000ns when we need same matrix. 
+
+## Performance
+
+Performance depends mainly on:
+
+1. CPU instruction extension( AVX2 or SSSE3 or none )
+2. number of data/parity vects
+3. unit size of calculation ( see it in rs_amd64.go )
+4. size of shards
+5. speed of memory (waste so much time on read/write mem, :D )
+6. performance of CPU
+7. the way of using ( reuse memory)
+
+And we must know the benchmark test is quite different with encoding/decoding in practice.
+
+Because in benchmark test loops, the CPU Cache will help a lot. In practice, we must reuse the memory to make the performance become as good as the benchmark test.
+
+Example of performance on my MacBook 2017 i7 2.8GHz. 10+4 (with 0.1.0).
+
+### Encoding:
+
+| Vector size | Speed (MB/S) |
+|----------------|--------------|
+| 1400B              |    7655.02  |
+| 4KB              |       10551.37  |
+| 64KB              |       9297.25 |
+| 1MB              |      6829.89 |
+| 16MB              |      6312.83 |
+
+### Reconstruct (use nil to point which one need repair):
+
+| Vector size | Speed (MB/S) |
+|----------------|--------------|
+| 1400B              |    4124.85  |
+| 4KB              |       5715.45 |
+| 64KB              |       6050.06 |
+| 1MB              |      5001.21 |
+| 16MB              |      5043.04 |
+
+### ReconstructWithPos (use a position list to point which one need repair, reuse the memory):
+
+| Vector size | Speed (MB/S) |
+|----------------|--------------|
+| 1400B              |    6170.24  |
+| 4KB              |       9444.86 |
+| 64KB              |       9311.30 |
+| 1MB              |      6781.06 |
+| 16MB              |      6285.34 |
+
+**reconstruct benchmark tests here run with inverse matrix cache, if there is no cache, it will cost more time( about 1000ns)**
+
+## Who is using this?
+
+1. https://github.com/xtaci/kcp-go -- A Production-Grade Reliable-UDP Library for golang
+
+## Links & Thanks
+* [Klauspost ReedSolomon](https://github.com/klauspost/reedsolomon)
+* [intel ISA-L](https://github.com/01org/isa-l)
+* [GF SIMD] (http://www.ssrc.ucsc.edu/papers/plank-fast13.pdf)
+* [asm2plan9s] (https://github.com/fwessels/asm2plan9s)

vendor/github.com/templexxx/reedsolomon/matrix.go

@@ -0,0 +1,156 @@
+package reedsolomon
+
+import "errors"
+
+type matrix []byte
+
+func genEncMatrixCauchy(d, p int) matrix {
+	t := d + p
+	m := make([]byte, t*d)
+	for i := 0; i < d; i++ {
+		m[i*d+i] = byte(1)
+	}
+
+	d2 := d * d
+	for i := d; i < t; i++ {
+		for j := 0; j < d; j++ {
+			d := i ^ j
+			a := inverseTbl[d]
+			m[d2] = byte(a)
+			d2++
+		}
+	}
+	return m
+}
+
+func gfExp(b byte, n int) byte {
+	if n == 0 {
+		return 1
+	}
+	if b == 0 {
+		return 0
+	}
+	a := logTbl[b]
+	ret := int(a) * n
+	for ret >= 255 {
+		ret -= 255
+	}
+	return byte(expTbl[ret])
+}
+
+func genVandMatrix(vm []byte, t, d int) {
+	for i := 0; i < t; i++ {
+		for j := 0; j < d; j++ {
+			vm[i*d+j] = gfExp(byte(i), j)
+		}
+	}
+}
+
+func (m matrix) mul(right matrix, rows, cols int, r []byte) {
+	for i := 0; i < rows; i++ {
+		for j := 0; j < cols; j++ {
+			var v byte
+			for k := 0; k < cols; k++ {
+				v ^= gfMul(m[i*cols+k], right[k*cols+j])
+			}
+			r[i*cols+j] = v
+		}
+	}
+}
+
+func genEncMatrixVand(d, p int) (matrix, error) {
+	t := d + p
+	buf := make([]byte, (2*t+4*d)*d)
+	vm := buf[:t*d]
+	genVandMatrix(vm, t, d)
+	top := buf[t*d : (t+d)*d]
+	copy(top, vm[:d*d])
+	raw := buf[(t+d)*d : (t+3*d)*d]
+	im := buf[(t+3*d)*d : (t+4*d)*d]
+	err := matrix(top).invert(raw, d, im)
+	if err != nil {
+		return nil, err
+	}
+	r := buf[(t+4*d)*d : (2*t+4*d)*d]
+	matrix(vm).mul(im, t, d, r)
+	return matrix(r), nil
+}
+
+// [I|m'] -> [m']
+func (m matrix) subMatrix(n int, r []byte) {
+	for i := 0; i < n; i++ {
+		off := i * n
+		copy(r[off:off+n], m[2*off+n:2*(off+n)])
+	}
+}
+
+func (m matrix) invert(raw matrix, n int, im []byte) error {
+	// [m] -> [m|I]
+	for i := 0; i < n; i++ {
+		t := i * n
+		copy(raw[2*t:2*t+n], m[t:t+n])
+		raw[2*t+i+n] = byte(1)
+	}
+	err := gauss(raw, n)
+	if err != nil {
+		return err
+	}
+	raw.subMatrix(n, im)
+	return nil
+}
+
+func (m matrix) swap(i, j, n int) {
+	for k := 0; k < n; k++ {
+		m[i*n+k], m[j*n+k] = m[j*n+k], m[i*n+k]
+	}
+}
+
+func gfMul(a, b byte) byte {
+	return mulTbl[a][b]
+}
+
+var errSingular = errors.New("rs.invert: matrix is singular")
+
+// [m|I] -> [I|m']
+func gauss(m matrix, n int) error {
+	n2 := 2 * n
+	for i := 0; i < n; i++ {
+		if m[i*n2+i] == 0 {
+			for j := i + 1; j < n; j++ {
+				if m[j*n2+i] != 0 {
+					m.swap(i, j, n2)
+					break
+				}
+			}
+		}
+		if m[i*n2+i] == 0 {
+			return errSingular
+		}
+		if m[i*n2+i] != 1 {
+			d := m[i*n2+i]
+			scale := inverseTbl[d]
+			for c := 0; c < n2; c++ {
+				m[i*n2+c] = gfMul(m[i*n2+c], scale)
+			}
+		}
+		for j := i + 1; j < n; j++ {
+			if m[j*n2+i] != 0 {
+				scale := m[j*n2+i]
+				for c := 0; c < n2; c++ {
+					m[j*n2+c] ^= gfMul(scale, m[i*n2+c])
+				}
+			}
+		}
+	}
+	for k := 0; k < n; k++ {
+		for j := 0; j < k; j++ {
+			if m[j*n2+k] != 0 {
+				scale := m[j*n2+k]
+				for c := 0; c < n2; c++ {
+					m[j*n2+c] ^= gfMul(scale, m[k*n2+c])
+				}
+			}
+		}
+	}
+	return nil
+}

vendor/github.com/templexxx/reedsolomon/rs.go

@@ -0,0 +1,280 @@
+/*
+	Reed-Solomon Codes over GF(2^8)
+	Primitive Polynomial:  x^8+x^4+x^3+x^2+1
+	Galois Filed arithmetic using Intel SIMD instructions (AVX2 or SSSE3)
+*/
+
+package reedsolomon
+
+import "errors"
+
+// Encoder implements for Reed-Solomon Encoding/Reconstructing
+type Encoder interface {
+	// Encode multiply generator-matrix with data
+	// len(vects) must be equal with num of data+parity
+	Encode(vects [][]byte) error
+	// Result of reconst will be put into origin position of vects
+	// it means if you lost vects[0], after reconst the vects[0]'s data will be back in vects[0]
+
+	// Reconstruct repair lost data & parity
+	// Set vect nil if lost
+	Reconstruct(vects [][]byte) error
+	// Reconstruct repair lost data
+	// Set vect nil if lost
+	ReconstructData(vects [][]byte) error
+	// ReconstWithPos repair lost data&parity with has&lost vects position
+	// Save bandwidth&disk I/O (cmp with Reconstruct, if the lost is less than num of parity)
+	// As erasure codes, we must know which vect is broken,
+	// so it's necessary to provide such APIs
+	// len(has) must equal num of data vects
+	// Example:
+	// in 3+2, the whole position: [0,1,2,3,4]
+	// if lost vects[0]
+	// the "has" could be [1,2,3] or [1,2,4] or ...
+	// then you must be sure that vects[1] vects[2] vects[3] have correct data (if the "has" is [1,2,3])
+	// the "dLost" will be [0]
+	// ps:
+	// 1. the above lists are in increasing orders  TODO support out-of-order
+	// 2. each vect has same len, don't set it nil
+	// so we don't need to make slice
+	ReconstWithPos(vects [][]byte, has, dLost, pLost []int) error
+	//// ReconstWithPos repair lost data with survived&lost vects position
+	//// Don't need to append position of parity lost into "lost"
+	ReconstDataWithPos(vects [][]byte, has, dLost []int) error
+}
+
+func checkCfg(d, p int) error {
+	if (d <= 0) || (p <= 0) {
+		return errors.New("rs.New: data or parity <= 0")
+	}
+	if d+p >= 256 {
+		return errors.New("rs.New: data+parity >= 256")
+	}
+	return nil
+}
+
+// New create an Encoder (vandermonde matrix as Encoding matrix)
+func New(data, parity int) (enc Encoder, err error) {
+	err = checkCfg(data, parity)
+	if err != nil {
+		return
+	}
+	e, err := genEncMatrixVand(data, parity)
+	if err != nil {
+		return
+	}
+	return newRS(data, parity, e), nil
+}
+
+// NewCauchy create an Encoder (cauchy matrix as Generator Matrix)
+func NewCauchy(data, parity int) (enc Encoder, err error) {
+	err = checkCfg(data, parity)
+	if err != nil {
+		return
+	}
+	e := genEncMatrixCauchy(data, parity)
+	return newRS(data, parity, e), nil
+}
+
+type encBase struct {
+	data   int
+	parity int
+	encode []byte
+	gen    []byte
+}
+
+func checkEnc(d, p int, vs [][]byte) (size int, err error) {
+	total := len(vs)
+	if d+p != total {
+		err = errors.New("rs.checkER: vects not match rs args")
+		return
+	}
+	size = len(vs[0])
+	if size == 0 {
+		err = errors.New("rs.checkER: vects size = 0")
+		return
+	}
+	for i := 1; i < total; i++ {
+		if len(vs[i]) != size {
+			err = errors.New("rs.checkER: vects size mismatch")
+			return
+		}
+	}
+	return
+}
+
+func (e *encBase) Encode(vects [][]byte) (err error) {
+	d := e.data
+	p := e.parity
+	_, err = checkEnc(d, p, vects)
+	if err != nil {
+		return
+	}
+	dv := vects[:d]
+	pv := vects[d:]
+	g := e.gen
+	for i := 0; i < d; i++ {
+		for j := 0; j < p; j++ {
+			if i != 0 {
+				mulVectAdd(g[j*d+i], dv[i], pv[j])
+			} else {
+				mulVect(g[j*d], dv[0], pv[j])
+			}
+		}
+	}
+	return
+}
+
+func mulVect(c byte, a, b []byte) {
+	t := mulTbl[c]
+	for i := 0; i < len(a); i++ {
+		b[i] = t[a[i]]
+	}
+}
+
+func mulVectAdd(c byte, a, b []byte) {
+	t := mulTbl[c]
+	for i := 0; i < len(a); i++ {
+		b[i] ^= t[a[i]]
+	}
+}
+
+func (e *encBase) Reconstruct(vects [][]byte) (err error) {
+	return e.reconstruct(vects, false)
+}
+
+func (e *encBase) ReconstructData(vects [][]byte) (err error) {
+	return e.reconstruct(vects, true)
+}
+
+func (e *encBase) ReconstWithPos(vects [][]byte, has, dLost, pLost []int) error {
+	return e.reconstWithPos(vects, has, dLost, pLost, false)
+}
+
+func (e *encBase) ReconstDataWithPos(vects [][]byte, has, dLost []int) error {
+	return e.reconstWithPos(vects, has, dLost, nil, true)
+}
+
+func (e *encBase) reconst(vects [][]byte, has, dLost, pLost []int, dataOnly bool) (err error) {
+	d := e.data
+	em := e.encode
+	dCnt := len(dLost)
+	size := len(vects[has[0]])
+	if dCnt != 0 {
+		vtmp := make([][]byte, d+dCnt)
+		for i, p := range has {
+			vtmp[i] = vects[p]
+		}
+		for i, p := range dLost {
+			if len(vects[p]) == 0 {
+				vects[p] = make([]byte, size)
+			}
+			vtmp[i+d] = vects[p]
+		}
+		matrixbuf := make([]byte, 4*d*d+dCnt*d)
+		m := matrixbuf[:d*d]
+		for i, l := range has {
+			copy(m[i*d:i*d+d], em[l*d:l*d+d])
+		}
+		raw := matrixbuf[d*d : 3*d*d]
+		im := matrixbuf[3*d*d : 4*d*d]
+		err2 := matrix(m).invert(raw, d, im)
+		if err2 != nil {
+			return err2
+		}
+		g := matrixbuf[4*d*d:]
+		for i, l := range dLost {
+			copy(g[i*d:i*d+d], im[l*d:l*d+d])
+		}
+		etmp := &encBase{data: d, parity: dCnt, gen: g}
+		err2 = etmp.Encode(vtmp[:d+dCnt])
+		if err2 != nil {
+			return err2
+		}
+	}
+	if dataOnly {
+		return
+	}
+	pCnt := len(pLost)
+	if pCnt != 0 {
+		vtmp := make([][]byte, d+pCnt)
+		g := make([]byte, pCnt*d)
+		for i, l := range pLost {
+			copy(g[i*d:i*d+d], em[l*d:l*d+d])
+		}
+		for i := 0; i < d; i++ {
+			vtmp[i] = vects[i]
+		}
+		for i, p := range pLost {
+			if len(vects[p]) == 0 {
+				vects[p] = make([]byte, size)
+			}
+			vtmp[i+d] = vects[p]
+		}
+		etmp := &encBase{data: d, parity: pCnt, gen: g}
+		err2 := etmp.Encode(vtmp[:d+pCnt])
+		if err2 != nil {
+			return err2
+		}
+	}
+	return
+}
+
+func (e *encBase) reconstWithPos(vects [][]byte, has, dLost, pLost []int, dataOnly bool) (err error) {
+	d := e.data
+	p := e.parity
+	// TODO check more, maybe element in has show in lost & deal with len(has) > d
+	if len(has) != d {
+		return errors.New("rs.Reconst: not enough vects")
+	}
+	dCnt := len(dLost)
+	if dCnt > p {
+		return errors.New("rs.Reconst: not enough vects")
+	}
+	pCnt := len(pLost)
+	if pCnt > p {
+		return errors.New("rs.Reconst: not enough vects")
+	}
+	return e.reconst(vects, has, dLost, pLost, dataOnly)
+}
+
+func (e *encBase) reconstruct(vects [][]byte, dataOnly bool) (err error) {
+	d := e.data
+	p := e.parity
+	t := d + p
+	listBuf := make([]int, t+p)
+	has := listBuf[:d]
+	dLost := listBuf[d:t]
+	pLost := listBuf[t : t+p]
+	hasCnt, dCnt, pCnt := 0, 0, 0
+	for i := 0; i < t; i++ {
+		if vects[i] != nil {
+			if hasCnt < d {
+				has[hasCnt] = i
+				hasCnt++
+			}
+		} else {
+			if i < d {
+				if dCnt < p {
+					dLost[dCnt] = i
+					dCnt++
+				} else {
+					return errors.New("rs.Reconst: not enough vects")
+				}
+			} else {
+				if pCnt < p {
+					pLost[pCnt] = i
+					pCnt++
+				} else {
+					return errors.New("rs.Reconst: not enough vects")
+				}
+			}
+		}
+	}
+	if hasCnt != d {
+		return errors.New("rs.Reconst: not enough vects")
+	}
+	dLost = dLost[:dCnt]
+	pLost = pLost[:pCnt]
+	return e.reconst(vects, has, dLost, pLost, dataOnly)
+}

vendor/github.com/templexxx/reedsolomon/rs_amd64.go

@@ -0,0 +1,868 @@
+package reedsolomon
+
+import (
+	"errors"
+	"sync"
+
+	"github.com/templexxx/cpufeat"
+)
+
+// SIMD Instruction Extensions
+const (
+	none = iota
+	avx2
+	ssse3
+)
+
+var extension = none
+
+func init() {
+	getEXT()
+}
+
+func getEXT() {
+	if cpufeat.X86.HasAVX2 {
+		extension = avx2
+		return
+	} else if cpufeat.X86.HasSSSE3 {
+		extension = ssse3
+		return
+	} else {
+		extension = none
+		return
+	}
+}
+
+//go:noescape
+func copy32B(dst, src []byte) // Need SSE2(introduced in 2001)
+
+func initTbl(g matrix, rows, cols int, tbl []byte) {
+	off := 0
+	for i := 0; i < cols; i++ {
+		for j := 0; j < rows; j++ {
+			c := g[j*cols+i]
+			t := lowhighTbl[c][:]
+			copy32B(tbl[off:off+32], t)
+			off += 32
+		}
+	}
+}
+
+// At most 3060 inverse matrix (when data=14, parity=4, calc by mathtool/cntinverse)
+// In practice,  data usually below 12, parity below 5
+func okCache(data, parity int) bool {
+	if data < 15 && parity < 5 { // you can change it, but the data+parity can't be bigger than 32 (tips: see the codes about make inverse matrix)
+		return true
+	}
+	return false
+}
+
+type (
+	encSSSE3 encSIMD
+	encAVX2  encSIMD
+	encSIMD  struct {
+		data   int
+		parity int
+		encode matrix
+		gen    matrix
+		tbl    []byte
+		// inverse matrix cache is design for small vect size ( < 4KB )
+		// it will save time for calculating inverse matrix
+		// but it's not so important for big vect size
+		enableCache  bool
+		inverseCache iCache
+	}
+	iCache struct {
+		sync.RWMutex
+		data map[uint32][]byte
+	}
+)
+
+func newRS(d, p int, em matrix) (enc Encoder) {
+	g := em[d*d:]
+	if extension == none {
+		return &encBase{data: d, parity: p, encode: em, gen: g}
+	}
+	t := make([]byte, d*p*32)
+	initTbl(g, p, d, t)
+	ok := okCache(d, p)
+	if extension == avx2 {
+		e := &encAVX2{data: d, parity: p, encode: em, gen: g, tbl: t, enableCache: ok,
+			inverseCache: iCache{data: make(map[uint32][]byte)}}
+		return e
+	}
+	e := &encSSSE3{data: d, parity: p, encode: em, gen: g, tbl: t, enableCache: ok,
+		inverseCache: iCache{data: make(map[uint32][]byte)}}
+	return e
+}
+
+// Size of sub-vector
+const unit int = 16 * 1024
+
+func getDo(n int) int {
+	if n < unit {
+		c := n >> 4
+		if c == 0 {
+			return unit
+		}
+		return c << 4
+	}
+	return unit
+}
+
+func (e *encAVX2) Encode(vects [][]byte) (err error) {
+	d := e.data
+	p := e.parity
+	size, err := checkEnc(d, p, vects)
+	if err != nil {
+		return
+	}
+	dv := vects[:d]
+	pv := vects[d:]
+	start, end := 0, 0
+	do := getDo(size)
+	for start < size {
+		end = start + do
+		if end <= size {
+			e.matrixMul(start, end, dv, pv)
+			start = end
+		} else {
+			e.matrixMulRemain(start, size, dv, pv)
+			start = size
+		}
+	}
+	return
+}
+
+//go:noescape
+func mulVectAVX2(tbl, d, p []byte)
+
+//go:noescape
+func mulVectAddAVX2(tbl, d, p []byte)
+
+func (e *encAVX2) matrixMul(start, end int, dv, pv [][]byte) {
+	d := e.data
+	p := e.parity
+	tbl := e.tbl
+	off := 0
+	for i := 0; i < d; i++ {
+		for j := 0; j < p; j++ {
+			t := tbl[off : off+32]
+			if i != 0 {
+				mulVectAddAVX2(t, dv[i][start:end], pv[j][start:end])
+			} else {
+				mulVectAVX2(t, dv[0][start:end], pv[j][start:end])
+			}
+			off += 32
+		}
+	}
+}
+
+func (e *encAVX2) matrixMulRemain(start, end int, dv, pv [][]byte) {
+	undone := end - start
+	do := (undone >> 4) << 4
+	d := e.data
+	p := e.parity
+	tbl := e.tbl
+	if do >= 16 {
+		end2 := start + do
+		off := 0
+		for i := 0; i < d; i++ {
+			for j := 0; j < p; j++ {
+				t := tbl[off : off+32]
+				if i != 0 {
+					mulVectAddAVX2(t, dv[i][start:end2], pv[j][start:end2])
+				} else {
+					mulVectAVX2(t, dv[0][start:end2], pv[j][start:end2])
+				}
+				off += 32
+			}
+		}
+		start = end
+	}
+	if undone > do {
+		// may recalculate some data, but still improve a lot
+		start2 := end - 16
+		if start2 >= 0 {
+			off := 0
+			for i := 0; i < d; i++ {
+				for j := 0; j < p; j++ {
+					t := tbl[off : off+32]
+					if i != 0 {
+						mulVectAddAVX2(t, dv[i][start2:end], pv[j][start2:end])
+					} else {
+						mulVectAVX2(t, dv[0][start2:end], pv[j][start2:end])
+					}
+					off += 32
+				}
+			}
+		} else {
+			g := e.gen
+			for i := 0; i < d; i++ {
+				for j := 0; j < p; j++ {
+					if i != 0 {
+						mulVectAdd(g[j*d+i], dv[i][start:], pv[j][start:])
+					} else {
+						mulVect(g[j*d], dv[0][start:], pv[j][start:])
+					}
+				}
+			}
+		}
+	}
+}
+
+// use generator-matrix but not tbls for encoding
+// it's design for reconstructing
+// for small vects, it cost to much time on initTbl, so drop it
+// and for big vects, the tbls can't impact much, because the cache will be filled with vects' data
+func (e *encAVX2) encodeGen(vects [][]byte) (err error) {
+	d := e.data
+	p := e.parity
+	size, err := checkEnc(d, p, vects)
+	if err != nil {
+		return
+	}
+	dv := vects[:d]
+	pv := vects[d:]
+	start, end := 0, 0
+	do := getDo(size)
+	for start < size {
+		end = start + do
+		if end <= size {
+			e.matrixMulGen(start, end, dv, pv)
+			start = end
+		} else {
+			e.matrixMulRemainGen(start, size, dv, pv)
+			start = size
+		}
+	}
+	return
+}
+
+func (e *encAVX2) matrixMulGen(start, end int, dv, pv [][]byte) {
+	d := e.data
+	p := e.parity
+	g := e.gen
+	for i := 0; i < d; i++ {
+		for j := 0; j < p; j++ {
+			t := lowhighTbl[g[j*d+i]][:]
+			if i != 0 {
+				mulVectAddAVX2(t, dv[i][start:end], pv[j][start:end])
+			} else {
+				mulVectAVX2(t, dv[0][start:end], pv[j][start:end])
+			}
+		}
+	}
+}
+
+func (e *encAVX2) matrixMulRemainGen(start, end int, dv, pv [][]byte) {
+	undone := end - start
+	do := (undone >> 4) << 4
+	d := e.data
+	p := e.parity
+	g := e.gen
+	if do >= 16 {
+		end2 := start + do
+		for i := 0; i < d; i++ {
+			for j := 0; j < p; j++ {
+				t := lowhighTbl[g[j*d+i]][:]
+				if i != 0 {
+					mulVectAddAVX2(t, dv[i][start:end2], pv[j][start:end2])
+				} else {
+					mulVectAVX2(t, dv[0][start:end2], pv[j][start:end2])
+				}
+			}
+		}
+		start = end
+	}
+	if undone > do {
+		start2 := end - 16
+		if start2 >= 0 {
+			for i := 0; i < d; i++ {
+				for j := 0; j < p; j++ {
+					t := lowhighTbl[g[j*d+i]][:]
+					if i != 0 {
+						mulVectAddAVX2(t, dv[i][start2:end], pv[j][start2:end])
+					} else {
+						mulVectAVX2(t, dv[0][start2:end], pv[j][start2:end])
+					}
+				}
+			}
+		} else {
+			for i := 0; i < d; i++ {
+				for j := 0; j < p; j++ {
+					if i != 0 {
+						mulVectAdd(g[j*d+i], dv[i][start:], pv[j][start:])
+					} else {
+						mulVect(g[j*d], dv[0][start:], pv[j][start:])
+					}
+				}
+			}
+		}
+	}
+}
+
+func (e *encAVX2) Reconstruct(vects [][]byte) (err error) {
+	return e.reconstruct(vects, false)
+}
+
+func (e *encAVX2) ReconstructData(vects [][]byte) (err error) {
+	return e.reconstruct(vects, true)
+}
+
+func (e *encAVX2) ReconstWithPos(vects [][]byte, has, dLost, pLost []int) error {
+	return e.reconstWithPos(vects, has, dLost, pLost, false)
+}
+
+func (e *encAVX2) ReconstDataWithPos(vects [][]byte, has, dLost []int) error {
+	return e.reconstWithPos(vects, has, dLost, nil, true)
+}
+
+func (e *encAVX2) makeGen(has, dLost []int) (gen []byte, err error) {
+	d := e.data
+	em := e.encode
+	cnt := len(dLost)
+	if !e.enableCache {
+		matrixbuf := make([]byte, 4*d*d+cnt*d)
+		m := matrixbuf[:d*d]
+		for i, l := range has {
+			copy(m[i*d:i*d+d], em[l*d:l*d+d])
+		}
+		raw := matrixbuf[d*d : 3*d*d]
+		im := matrixbuf[3*d*d : 4*d*d]
+		err2 := matrix(m).invert(raw, d, im)
+		if err2 != nil {
+			return nil, err2
+		}
+		g := matrixbuf[4*d*d:]
+		for i, l := range dLost {
+			copy(g[i*d:i*d+d], im[l*d:l*d+d])
+		}
+		return g, nil
+	}
+	var ikey uint32
+	for _, p := range has {
+		ikey += 1 << uint8(p)
+	}
+	e.inverseCache.RLock()
+	v, ok := e.inverseCache.data[ikey]
+	if ok {
+		im := v
+		g := make([]byte, cnt*d)
+		for i, l := range dLost {
+			copy(g[i*d:i*d+d], im[l*d:l*d+d])
+		}
+		e.inverseCache.RUnlock()
+		return g, nil
+	}
+	e.inverseCache.RUnlock()
+	matrixbuf := make([]byte, 4*d*d+cnt*d)
+	m := matrixbuf[:d*d]
+	for i, l := range has {
+		copy(m[i*d:i*d+d], em[l*d:l*d+d])
+	}
+	raw := matrixbuf[d*d : 3*d*d]
+	im := matrixbuf[3*d*d : 4*d*d]
+	err2 := matrix(m).invert(raw, d, im)
+	if err2 != nil {
+		return nil, err2
+	}
+	e.inverseCache.Lock()
+	e.inverseCache.data[ikey] = im
+	e.inverseCache.Unlock()
+	g := matrixbuf[4*d*d:]
+	for i, l := range dLost {
+		copy(g[i*d:i*d+d], im[l*d:l*d+d])
+	}
+	return g, nil
+}
+
+func (e *encAVX2) reconst(vects [][]byte, has, dLost, pLost []int, dataOnly bool) (err error) {
+	d := e.data
+	em := e.encode
+	dCnt := len(dLost)
+	size := len(vects[has[0]])
+	if dCnt != 0 {
+		vtmp := make([][]byte, d+dCnt)
+		for i, p := range has {
+			vtmp[i] = vects[p]
+		}
+		for i, p := range dLost {
+			if len(vects[p]) == 0 {
+				vects[p] = make([]byte, size)
+			}
+			vtmp[i+d] = vects[p]
+		}
+		g, err2 := e.makeGen(has, dLost)
+		if err2 != nil {
+			return
+		}
+		etmp := &encAVX2{data: d, parity: dCnt, gen: g}
+		err2 = etmp.encodeGen(vtmp)
+		if err2 != nil {
+			return err2
+		}
+	}
+	if dataOnly {
+		return
+	}
+	pCnt := len(pLost)
+	if pCnt != 0 {
+		g := make([]byte, pCnt*d)
+		for i, l := range pLost {
+			copy(g[i*d:i*d+d], em[l*d:l*d+d])
+		}
+		vtmp := make([][]byte, d+pCnt)
+		for i := 0; i < d; i++ {
+			vtmp[i] = vects[i]
+		}
+		for i, p := range pLost {
+			if len(vects[p]) == 0 {
+				vects[p] = make([]byte, size)
+			}
+			vtmp[i+d] = vects[p]
+		}
+		etmp := &encAVX2{data: d, parity: pCnt, gen: g}
+		err2 := etmp.encodeGen(vtmp)
+		if err2 != nil {
+			return err2
+		}
+	}
+	return
+}
+
+func (e *encAVX2) reconstWithPos(vects [][]byte, has, dLost, pLost []int, dataOnly bool) (err error) {
+	d := e.data
+	p := e.parity
+	if len(has) != d {
+		return errors.New("rs.Reconst: not enough vects")
+	}
+	dCnt := len(dLost)
+	if dCnt > p {
+		return errors.New("rs.Reconst: not enough vects")
+	}
+	pCnt := len(pLost)
+	if pCnt > p {
+		return errors.New("rs.Reconst: not enough vects")
+	}
+	return e.reconst(vects, has, dLost, pLost, dataOnly)
+}
+
+func (e *encAVX2) reconstruct(vects [][]byte, dataOnly bool) (err error) {
+	d := e.data
+	p := e.parity
+	t := d + p
+	listBuf := make([]int, t+p)
+	has := listBuf[:d]
+	dLost := listBuf[d:t]
+	pLost := listBuf[t : t+p]
+	hasCnt, dCnt, pCnt := 0, 0, 0
+	for i := 0; i < t; i++ {
+		if vects[i] != nil {
+			if hasCnt < d {
+				has[hasCnt] = i
+				hasCnt++
+			}
+		} else {
+			if i < d {
+				if dCnt < p {
+					dLost[dCnt] = i
+					dCnt++
+				} else {
+					return errors.New("rs.Reconst: not enough vects")
+				}
+			} else {
+				if pCnt < p {
+					pLost[pCnt] = i
+					pCnt++
+				} else {
+					return errors.New("rs.Reconst: not enough vects")
+				}
+			}
+		}
+	}
+	if hasCnt != d {
+		return errors.New("rs.Reconst: not enough vects")
+	}
+	dLost = dLost[:dCnt]
+	pLost = pLost[:pCnt]
+	return e.reconst(vects, has, dLost, pLost, dataOnly)
+}
+
+func (e *encSSSE3) Encode(vects [][]byte) (err error) {
+	d := e.data
+	p := e.parity
+	size, err := checkEnc(d, p, vects)
+	if err != nil {
+		return
+	}
+	dv := vects[:d]
+	pv := vects[d:]
+	start, end := 0, 0
+	do := getDo(size)
+	for start < size {
+		end = start + do
+		if end <= size {
+			e.matrixMul(start, end, dv, pv)
+			start = end
+		} else {
+			e.matrixMulRemain(start, size, dv, pv)
+			start = size
+		}
+	}
+	return
+}
+
+//go:noescape
+func mulVectSSSE3(tbl, d, p []byte)
+
+//go:noescape
+func mulVectAddSSSE3(tbl, d, p []byte)
+
+func (e *encSSSE3) matrixMul(start, end int, dv, pv [][]byte) {
+	d := e.data
+	p := e.parity
+	tbl := e.tbl
+	off := 0
+	for i := 0; i < d; i++ {
+		for j := 0; j < p; j++ {
+			t := tbl[off : off+32]
+			if i != 0 {
+				mulVectAddSSSE3(t, dv[i][start:end], pv[j][start:end])
+			} else {
+				mulVectSSSE3(t, dv[0][start:end], pv[j][start:end])
+			}
+			off += 32
+		}
+	}
+}
+
+func (e *encSSSE3) matrixMulRemain(start, end int, dv, pv [][]byte) {
+	undone := end - start
+	do := (undone >> 4) << 4
+	d := e.data
+	p := e.parity
+	tbl := e.tbl
+	if do >= 16 {
+		end2 := start + do
+		off := 0
+		for i := 0; i < d; i++ {
+			for j := 0; j < p; j++ {
+				t := tbl[off : off+32]
+				if i != 0 {
+					mulVectAddSSSE3(t, dv[i][start:end2], pv[j][start:end2])
+				} else {
+					mulVectSSSE3(t, dv[0][start:end2], pv[j][start:end2])
+				}
+				off += 32
+			}
+		}
+		start = end
+	}
+	if undone > do {
+		start2 := end - 16
+		if start2 >= 0 {
+			off := 0
+			for i := 0; i < d; i++ {
+				for j := 0; j < p; j++ {
+					t := tbl[off : off+32]
+					if i != 0 {
+						mulVectAddSSSE3(t, dv[i][start2:end], pv[j][start2:end])
+					} else {
+						mulVectSSSE3(t, dv[0][start2:end], pv[j][start2:end])
+					}
+					off += 32
+				}
+			}
+		} else {
+			g := e.gen
+			for i := 0; i < d; i++ {
+				for j := 0; j < p; j++ {
+					if i != 0 {
+						mulVectAdd(g[j*d+i], dv[i][start:], pv[j][start:])
+					} else {
+						mulVect(g[j*d], dv[0][start:], pv[j][start:])
+					}
+				}
+			}
+		}
+	}
+}
+
+// use generator-matrix but not tbls for encoding
+// it's design for reconstructing
+// for small vects, it cost to much time on initTbl, so drop it
+// and for big vects, the tbls can't impact much, because the cache will be filled with vects' data
+func (e *encSSSE3) encodeGen(vects [][]byte) (err error) {
+	d := e.data
+	p := e.parity
+	size, err := checkEnc(d, p, vects)
+	if err != nil {
+		return
+	}
+	dv := vects[:d]
+	pv := vects[d:]
+	start, end := 0, 0
+	do := getDo(size)
+	for start < size {
+		end = start + do
+		if end <= size {
+			e.matrixMulGen(start, end, dv, pv)
+			start = end
+		} else {
+			e.matrixMulRemainGen(start, size, dv, pv)
+			start = size
+		}
+	}
+	return
+}
+
+func (e *encSSSE3) matrixMulGen(start, end int, dv, pv [][]byte) {
+	d := e.data
+	p := e.parity
+	g := e.gen
+	for i := 0; i < d; i++ {
+		for j := 0; j < p; j++ {
+			t := lowhighTbl[g[j*d+i]][:]
+			if i != 0 {
+				mulVectAddSSSE3(t, dv[i][start:end], pv[j][start:end])
+			} else {
+				mulVectSSSE3(t, dv[0][start:end], pv[j][start:end])
+			}
+		}
+	}
+}
+
+func (e *encSSSE3) matrixMulRemainGen(start, end int, dv, pv [][]byte) {
+	undone := end - start
+	do := (undone >> 4) << 4
+	d := e.data
+	p := e.parity
+	g := e.gen
+	if do >= 16 {
+		end2 := start + do
+		for i := 0; i < d; i++ {
+			for j := 0; j < p; j++ {
+				t := lowhighTbl[g[j*d+i]][:]
+				if i != 0 {
+					mulVectAddSSSE3(t, dv[i][start:end2], pv[j][start:end2])
+				} else {
+					mulVectSSSE3(t, dv[0][start:end2], pv[j][start:end2])
+				}
+			}
+		}
+		start = end
+	}
+	if undone > do {
+		start2 := end - 16
+		if start2 >= 0 {
+			for i := 0; i < d; i++ {
+				for j := 0; j < p; j++ {
+					t := lowhighTbl[g[j*d+i]][:]
+					if i != 0 {
+						mulVectAddSSSE3(t, dv[i][start2:end], pv[j][start2:end])
+					} else {
+						mulVectSSSE3(t, dv[0][start2:end], pv[j][start2:end])
+					}
+				}
+			}
+		} else {
+			for i := 0; i < d; i++ {
+				for j := 0; j < p; j++ {
+					if i != 0 {
+						mulVectAdd(g[j*d+i], dv[i][start:], pv[j][start:])
+					} else {
+						mulVect(g[j*d], dv[0][start:], pv[j][start:])
+					}
+				}
+			}
+		}
+	}
+}
+
+func (e *encSSSE3) Reconstruct(vects [][]byte) (err error) {
+	return e.reconstruct(vects, false)
+}
+
+func (e *encSSSE3) ReconstructData(vects [][]byte) (err error) {
+	return e.reconstruct(vects, true)
+}
+
+func (e *encSSSE3) ReconstWithPos(vects [][]byte, has, dLost, pLost []int) error {
+	return e.reconstWithPos(vects, has, dLost, pLost, false)
+}
+
+func (e *encSSSE3) ReconstDataWithPos(vects [][]byte, has, dLost []int) error {
+	return e.reconstWithPos(vects, has, dLost, nil, true)
+}
+
+func (e *encSSSE3) makeGen(has, dLost []int) (gen []byte, err error) {
+	d := e.data
+	em := e.encode
+	cnt := len(dLost)
+	if !e.enableCache {
+		matrixbuf := make([]byte, 4*d*d+cnt*d)
+		m := matrixbuf[:d*d]
+		for i, l := range has {
+			copy(m[i*d:i*d+d], em[l*d:l*d+d])
+		}
+		raw := matrixbuf[d*d : 3*d*d]
+		im := matrixbuf[3*d*d : 4*d*d]
+		err2 := matrix(m).invert(raw, d, im)
+		if err2 != nil {
+			return nil, err2
+		}
+		g := matrixbuf[4*d*d:]
+		for i, l := range dLost {
+			copy(g[i*d:i*d+d], im[l*d:l*d+d])
+		}
+		return g, nil
+	}
+	var ikey uint32
+	for _, p := range has {
+		ikey += 1 << uint8(p)
+	}
+	e.inverseCache.RLock()
+	v, ok := e.inverseCache.data[ikey]
+	if ok {
+		im := v
+		g := make([]byte, cnt*d)
+		for i, l := range dLost {
+			copy(g[i*d:i*d+d], im[l*d:l*d+d])
+		}
+		e.inverseCache.RUnlock()
+		return g, nil
+	}
+	e.inverseCache.RUnlock()
+	matrixbuf := make([]byte, 4*d*d+cnt*d)
+	m := matrixbuf[:d*d]
+	for i, l := range has {
+		copy(m[i*d:i*d+d], em[l*d:l*d+d])
+	}
+	raw := matrixbuf[d*d : 3*d*d]
+	im := matrixbuf[3*d*d : 4*d*d]
+	err2 := matrix(m).invert(raw, d, im)
+	if err2 != nil {
+		return nil, err2
+	}
+	e.inverseCache.Lock()
+	e.inverseCache.data[ikey] = im
+	e.inverseCache.Unlock()
+	g := matrixbuf[4*d*d:]
+	for i, l := range dLost {
+		copy(g[i*d:i*d+d], im[l*d:l*d+d])
+	}
+	return g, nil
+}
+
+func (e *encSSSE3) reconst(vects [][]byte, has, dLost, pLost []int, dataOnly bool) (err error) {
+	d := e.data
+	em := e.encode
+	dCnt := len(dLost)
+	size := len(vects[has[0]])
+	if dCnt != 0 {
+		vtmp := make([][]byte, d+dCnt)
+		for i, p := range has {
+			vtmp[i] = vects[p]
+		}
+		for i, p := range dLost {
+			if len(vects[p]) == 0 {
+				vects[p] = make([]byte, size)
+			}
+			vtmp[i+d] = vects[p]
+		}
+		g, err2 := e.makeGen(has, dLost)
+		if err2 != nil {
+			return
+		}
+		etmp := &encSSSE3{data: d, parity: dCnt, gen: g}
+		err2 = etmp.encodeGen(vtmp)
+		if err2 != nil {
+			return err2
+		}
+	}
+	if dataOnly {
+		return
+	}
+	pCnt := len(pLost)
+	if pCnt != 0 {
+		g := make([]byte, pCnt*d)
+		for i, l := range pLost {
+			copy(g[i*d:i*d+d], em[l*d:l*d+d])
+		}
+		vtmp := make([][]byte, d+pCnt)
+		for i := 0; i < d; i++ {
+			vtmp[i] = vects[i]
+		}
+		for i, p := range pLost {
+			if len(vects[p]) == 0 {
+				vects[p] = make([]byte, size)
+			}
+			vtmp[i+d] = vects[p]
+		}
+		etmp := &encSSSE3{data: d, parity: pCnt, gen: g}
+		err2 := etmp.encodeGen(vtmp)
+		if err2 != nil {
+			return err2
+		}
+	}
+	return
+}
+
+func (e *encSSSE3) reconstWithPos(vects [][]byte, has, dLost, pLost []int, dataOnly bool) (err error) {
+	d := e.data
+	p := e.parity
+	if len(has) != d {
+		return errors.New("rs.Reconst: not enough vects")
+	}
+	dCnt := len(dLost)
+	if dCnt > p {
+		return errors.New("rs.Reconst: not enough vects")
+	}
+	pCnt := len(pLost)
+	if pCnt > p {
+		return errors.New("rs.Reconst: not enough vects")
+	}
+	return e.reconst(vects, has, dLost, pLost, dataOnly)
+}
+
+func (e *encSSSE3) reconstruct(vects [][]byte, dataOnly bool) (err error) {
+	d := e.data
+	p := e.parity
+	t := d + p
+	listBuf := make([]int, t+p)
+	has := listBuf[:d]
+	dLost := listBuf[d:t]
+	pLost := listBuf[t : t+p]
+	hasCnt, dCnt, pCnt := 0, 0, 0
+	for i := 0; i < t; i++ {
+		if vects[i] != nil {
+			if hasCnt < d {
+				has[hasCnt] = i
+				hasCnt++
+			}
+		} else {
+			if i < d {
+				if dCnt < p {
+					dLost[dCnt] = i
+					dCnt++
+				} else {
+					return errors.New("rs.Reconst: not enough vects")
+				}
+			} else {
+				if pCnt < p {
+					pLost[pCnt] = i
+					pCnt++
+				} else {
+					return errors.New("rs.Reconst: not enough vects")
+				}
+			}
+		}
+	}
+	if hasCnt != d {
+		return errors.New("rs.Reconst: not enough vects")
+	}
+	dLost = dLost[:dCnt]
+	pLost = pLost[:pCnt]
+	return e.reconst(vects, has, dLost, pLost, dataOnly)
+}

vendor/github.com/templexxx/reedsolomon/rs_amd64.s

@@ -0,0 +1,401 @@
+// Reference: www.ssrc.ucsc.edu/Papers/plank-fast13.pdf
+
+#include "textflag.h"
+
+#define low_tbl Y0
+#define high_tbl Y1
+#define mask Y2
+#define in0  Y3
+#define in1  Y4
+#define in2  Y5
+#define in3  Y6
+#define in4  Y7
+#define in5  Y8
+#define in0_h  Y10
+#define in1_h  Y11
+#define in2_h  Y12
+#define in3_h  Y13
+#define in4_h  Y14
+#define in5_h  Y15
+
+#define in  BX
+#define out DI
+#define len R8
+#define pos R9
+
+#define tmp0 R10
+
+#define low_tblx X0
+#define high_tblx X1
+#define maskx X2
+#define in0x X3
+#define in0_hx X10
+#define tmp0x  X9
+#define tmp1x  X11
+#define tmp2x  X12
+#define tmp3x  X13
+
+
+// func mulVectAVX2(tbl, d, p []byte)
+TEXT ·mulVectAVX2(SB), NOSPLIT, $0
+    MOVQ         i+24(FP), in
+	MOVQ         o+48(FP), out
+	MOVQ         tbl+0(FP), tmp0
+	VMOVDQU      (tmp0), low_tblx
+	VMOVDQU      16(tmp0), high_tblx
+	MOVB         $0x0f, DX
+	LONG         $0x2069e3c4; WORD $0x00d2   // VPINSRB $0x00, EDX, XMM2, XMM2
+	VPBROADCASTB maskx, maskx
+	MOVQ         in_len+32(FP), len
+	TESTQ        $31, len
+	JNZ          one16b
+
+ymm:
+    VINSERTI128  $1, low_tblx, low_tbl, low_tbl
+    VINSERTI128  $1, high_tblx, high_tbl, high_tbl
+    VINSERTI128  $1, maskx, mask, mask
+    TESTQ        $255, len
+    JNZ          not_aligned
+
+// 256bytes/loop
+aligned:
+    MOVQ         $0, pos
+
+loop256b:
+	VMOVDQU (in)(pos*1), in0
+	VPSRLQ  $4, in0, in0_h
+	VPAND   mask, in0_h, in0_h
+	VPAND   mask, in0, in0
+	VPSHUFB in0_h, high_tbl, in0_h
+	VPSHUFB in0, low_tbl, in0
+	VPXOR   in0, in0_h, in0
+	VMOVDQU in0, (out)(pos*1)
+
+    VMOVDQU 32(in)(pos*1), in1
+	VPSRLQ  $4, in1, in1_h
+	VPAND   mask, in1_h, in1_h
+	VPAND   mask, in1, in1
+	VPSHUFB in1_h, high_tbl, in1_h
+	VPSHUFB in1, low_tbl, in1
+	VPXOR   in1, in1_h, in1
+	VMOVDQU in1, 32(out)(pos*1)
+
+    VMOVDQU 64(in)(pos*1), in2
+	VPSRLQ  $4, in2, in2_h
+	VPAND   mask, in2_h, in2_h
+	VPAND   mask, in2, in2
+	VPSHUFB in2_h, high_tbl, in2_h
+	VPSHUFB in2, low_tbl, in2
+	VPXOR   in2, in2_h, in2
+	VMOVDQU in2, 64(out)(pos*1)
+
+    VMOVDQU 96(in)(pos*1), in3
+	VPSRLQ  $4, in3, in3_h
+	VPAND   mask, in3_h, in3_h
+	VPAND   mask, in3, in3
+	VPSHUFB in3_h, high_tbl, in3_h
+	VPSHUFB in3, low_tbl, in3
+	VPXOR   in3, in3_h, in3
+	VMOVDQU in3, 96(out)(pos*1)
+
+    VMOVDQU 128(in)(pos*1), in4
+	VPSRLQ  $4, in4, in4_h
+	VPAND   mask, in4_h, in4_h
+	VPAND   mask, in4, in4
+	VPSHUFB in4_h, high_tbl, in4_h
+	VPSHUFB in4, low_tbl, in4
+	VPXOR   in4, in4_h, in4
+	VMOVDQU in4, 128(out)(pos*1)
+
+    VMOVDQU 160(in)(pos*1), in5
+	VPSRLQ  $4, in5, in5_h
+	VPAND   mask, in5_h, in5_h
+	VPAND   mask, in5, in5
+	VPSHUFB in5_h, high_tbl, in5_h
+	VPSHUFB in5, low_tbl, in5
+	VPXOR   in5, in5_h, in5
+	VMOVDQU in5, 160(out)(pos*1)
+
+    VMOVDQU 192(in)(pos*1), in0
+	VPSRLQ  $4, in0, in0_h
+	VPAND   mask, in0_h, in0_h
+	VPAND   mask, in0, in0
+	VPSHUFB in0_h, high_tbl, in0_h
+	VPSHUFB in0, low_tbl, in0
+	VPXOR   in0, in0_h, in0
+	VMOVDQU in0, 192(out)(pos*1)
+
+    VMOVDQU 224(in)(pos*1), in1
+	VPSRLQ  $4, in1, in1_h
+	VPAND   mask, in1_h, in1_h
+	VPAND   mask, in1, in1
+	VPSHUFB in1_h, high_tbl, in1_h
+	VPSHUFB in1, low_tbl, in1
+	VPXOR   in1, in1_h, in1
+	VMOVDQU in1, 224(out)(pos*1)
+
+	ADDQ    $256, pos
+	CMPQ    len, pos
+	JNE     loop256b
+	VZEROUPPER
+	RET
+
+not_aligned:
+    MOVQ    len, tmp0
+    ANDQ    $255, tmp0
+
+loop32b:
+    VMOVDQU -32(in)(len*1), in0
+	VPSRLQ  $4, in0, in0_h
+	VPAND   mask, in0_h, in0_h
+	VPAND   mask, in0, in0
+	VPSHUFB in0_h, high_tbl, in0_h
+	VPSHUFB in0, low_tbl, in0
+	VPXOR   in0, in0_h, in0
+	VMOVDQU in0, -32(out)(len*1)
+	SUBQ    $32, len
+	SUBQ    $32, tmp0
+	JG      loop32b
+	CMPQ    len, $256
+	JGE     aligned
+	VZEROUPPER
+	RET
+
+one16b:
+    VMOVDQU  -16(in)(len*1), in0x
+    VPSRLQ   $4, in0x, in0_hx
+    VPAND    maskx, in0x, in0x
+    VPAND    maskx, in0_hx, in0_hx
+    VPSHUFB  in0_hx, high_tblx, in0_hx
+    VPSHUFB  in0x, low_tblx, in0x
+    VPXOR    in0x, in0_hx, in0x
+	VMOVDQU  in0x, -16(out)(len*1)
+	SUBQ     $16, len
+	CMPQ     len, $0
+	JNE      ymm
+	RET
+
+// func mulVectAddAVX2(tbl, d, p []byte)
+TEXT ·mulVectAddAVX2(SB), NOSPLIT, $0
+    MOVQ         i+24(FP), in
+	MOVQ         o+48(FP), out
+	MOVQ         tbl+0(FP), tmp0
+	VMOVDQU      (tmp0), low_tblx
+	VMOVDQU      16(tmp0), high_tblx
+	MOVB         $0x0f, DX
+	LONG         $0x2069e3c4; WORD $0x00d2
+	VPBROADCASTB maskx, maskx
+	MOVQ         in_len+32(FP), len
+	TESTQ        $31, len
+	JNZ          one16b
+
+ymm:
+    VINSERTI128  $1, low_tblx, low_tbl, low_tbl
+    VINSERTI128  $1, high_tblx, high_tbl, high_tbl
+    VINSERTI128  $1, maskx, mask, mask
+    TESTQ        $255, len
+    JNZ          not_aligned
+
+aligned:
+    MOVQ         $0, pos
+
+loop256b:
+    VMOVDQU (in)(pos*1), in0
+	VPSRLQ  $4, in0, in0_h
+	VPAND   mask, in0_h, in0_h
+	VPAND   mask, in0, in0
+	VPSHUFB in0_h, high_tbl, in0_h
+	VPSHUFB in0, low_tbl, in0
+	VPXOR   in0, in0_h, in0
+	VPXOR   (out)(pos*1), in0, in0
+	VMOVDQU in0, (out)(pos*1)
+
+    VMOVDQU 32(in)(pos*1), in1
+	VPSRLQ  $4, in1, in1_h
+	VPAND   mask, in1_h, in1_h
+	VPAND   mask, in1, in1
+	VPSHUFB in1_h, high_tbl, in1_h
+	VPSHUFB in1, low_tbl, in1
+	VPXOR   in1, in1_h, in1
+	VPXOR   32(out)(pos*1), in1, in1
+	VMOVDQU in1, 32(out)(pos*1)
+
+    VMOVDQU 64(in)(pos*1), in2
+	VPSRLQ  $4, in2, in2_h
+	VPAND   mask, in2_h, in2_h
+	VPAND   mask, in2, in2
+	VPSHUFB in2_h, high_tbl, in2_h
+	VPSHUFB in2, low_tbl, in2
+	VPXOR   in2, in2_h, in2
+	VPXOR   64(out)(pos*1), in2, in2
+	VMOVDQU in2, 64(out)(pos*1)
+
+    VMOVDQU 96(in)(pos*1), in3
+	VPSRLQ  $4, in3, in3_h
+	VPAND   mask, in3_h, in3_h
+	VPAND   mask, in3, in3
+	VPSHUFB in3_h, high_tbl, in3_h
+	VPSHUFB in3, low_tbl, in3
+	VPXOR   in3, in3_h, in3
+	VPXOR   96(out)(pos*1), in3, in3
+	VMOVDQU in3, 96(out)(pos*1)
+
+    VMOVDQU 128(in)(pos*1), in4
+	VPSRLQ  $4, in4, in4_h
+	VPAND   mask, in4_h, in4_h
+	VPAND   mask, in4, in4
+	VPSHUFB in4_h, high_tbl, in4_h
+	VPSHUFB in4, low_tbl, in4
+	VPXOR   in4, in4_h, in4
+	VPXOR   128(out)(pos*1), in4, in4
+	VMOVDQU in4, 128(out)(pos*1)
+
+    VMOVDQU 160(in)(pos*1), in5
+	VPSRLQ  $4, in5, in5_h
+	VPAND   mask, in5_h, in5_h
+	VPAND   mask, in5, in5
+	VPSHUFB in5_h, high_tbl, in5_h
+	VPSHUFB in5, low_tbl, in5
+	VPXOR   in5, in5_h, in5
+	VPXOR   160(out)(pos*1), in5, in5
+	VMOVDQU in5, 160(out)(pos*1)
+
+    VMOVDQU 192(in)(pos*1), in0
+	VPSRLQ  $4, in0, in0_h
+	VPAND   mask, in0_h, in0_h
+	VPAND   mask, in0, in0
+	VPSHUFB in0_h, high_tbl, in0_h
+	VPSHUFB in0, low_tbl, in0
+	VPXOR   in0, in0_h, in0
+	VPXOR   192(out)(pos*1), in0, in0
+	VMOVDQU in0, 192(out)(pos*1)
+
+    VMOVDQU 224(in)(pos*1), in1
+	VPSRLQ  $4, in1, in1_h
+	VPAND   mask, in1_h, in1_h
+	VPAND   mask, in1, in1
+	VPSHUFB in1_h, high_tbl, in1_h
+	VPSHUFB in1, low_tbl, in1
+	VPXOR   in1, in1_h, in1
+	VPXOR   224(out)(pos*1), in1, in1
+	VMOVDQU in1, 224(out)(pos*1)
+
+	ADDQ    $256, pos
+	CMPQ    len, pos
+	JNE     loop256b
+	VZEROUPPER
+	RET
+
+not_aligned:
+    MOVQ    len, tmp0
+    ANDQ    $255, tmp0
+
+loop32b:
+    VMOVDQU -32(in)(len*1), in0
+	VPSRLQ  $4, in0, in0_h
+	VPAND   mask, in0_h, in0_h
+	VPAND   mask, in0, in0
+	VPSHUFB in0_h, high_tbl, in0_h
+	VPSHUFB in0, low_tbl, in0
+	VPXOR   in0, in0_h, in0
+	VPXOR   -32(out)(len*1), in0, in0
+	VMOVDQU in0, -32(out)(len*1)
+	SUBQ    $32, len
+	SUBQ    $32, tmp0
+	JG      loop32b
+	CMPQ    len, $256
+	JGE     aligned
+	VZEROUPPER
+	RET
+
+one16b:
+    VMOVDQU  -16(in)(len*1), in0x
+    VPSRLQ   $4, in0x, in0_hx
+    VPAND    maskx, in0x, in0x
+    VPAND    maskx, in0_hx, in0_hx
+    VPSHUFB  in0_hx, high_tblx, in0_hx
+    VPSHUFB  in0x, low_tblx, in0x
+    VPXOR    in0x, in0_hx, in0x
+    VPXOR    -16(out)(len*1), in0x, in0x
+	VMOVDQU  in0x, -16(out)(len*1)
+	SUBQ     $16, len
+	CMPQ     len, $0
+	JNE      ymm
+	RET
+
+// func mulVectSSSE3(tbl, d, p []byte)
+TEXT ·mulVectSSSE3(SB), NOSPLIT, $0
+    MOVQ    i+24(FP), in
+	MOVQ    o+48(FP), out
+	MOVQ    tbl+0(FP), tmp0
+	MOVOU   (tmp0), low_tblx
+	MOVOU   16(tmp0), high_tblx
+    MOVB    $15, tmp0
+    MOVQ    tmp0, maskx
+    PXOR    tmp0x, tmp0x
+   	PSHUFB  tmp0x, maskx
+	MOVQ    in_len+32(FP), len
+	SHRQ    $4, len
+
+loop:
+	MOVOU  (in), in0x
+	MOVOU  in0x, in0_hx
+	PSRLQ  $4, in0_hx
+	PAND   maskx, in0x
+	PAND   maskx, in0_hx
+	MOVOU  low_tblx, tmp1x
+	MOVOU  high_tblx, tmp2x
+	PSHUFB in0x, tmp1x
+	PSHUFB in0_hx, tmp2x
+	PXOR   tmp1x, tmp2x
+	MOVOU  tmp2x, (out)
+	ADDQ   $16, in
+	ADDQ   $16, out
+	SUBQ   $1, len
+	JNZ    loop
+	RET
+
+// func mulVectAddSSSE3(tbl, d, p []byte)
+TEXT ·mulVectAddSSSE3(SB), NOSPLIT, $0
+    MOVQ    i+24(FP), in
+	MOVQ    o+48(FP), out
+	MOVQ    tbl+0(FP), tmp0
+	MOVOU   (tmp0), low_tblx
+	MOVOU   16(tmp0), high_tblx
+    MOVB    $15, tmp0
+    MOVQ    tmp0, maskx
+    PXOR    tmp0x, tmp0x
+   	PSHUFB  tmp0x, maskx
+	MOVQ    in_len+32(FP), len
+	SHRQ    $4, len
+
+loop:
+	MOVOU  (in), in0x
+	MOVOU  in0x, in0_hx
+	PSRLQ  $4, in0_hx
+	PAND   maskx, in0x
+	PAND   maskx, in0_hx
+	MOVOU  low_tblx, tmp1x
+	MOVOU  high_tblx, tmp2x
+	PSHUFB in0x, tmp1x
+	PSHUFB in0_hx, tmp2x
+	PXOR   tmp1x, tmp2x
+	MOVOU  (out), tmp3x
+	PXOR   tmp3x, tmp2x
+	MOVOU  tmp2x, (out)
+	ADDQ   $16, in
+	ADDQ   $16, out
+	SUBQ   $1, len
+	JNZ    loop
+	RET
+
+// func copy32B(dst, src []byte)
+TEXT ·copy32B(SB), NOSPLIT, $0
+    MOVQ dst+0(FP), SI
+    MOVQ src+24(FP), DX
+    MOVOU (DX), X0
+    MOVOU 16(DX), X1
+    MOVOU X0, (SI)
+    MOVOU X1, 16(SI)
+    RET
+	

vendor/github.com/templexxx/reedsolomon/rs_other.go

@@ -0,0 +1,8 @@
+// +build !amd64
+
+package reedsolomon
+
+func newRS(d, p int, em matrix) (enc Encoder) {
+	g := em[d*d:]
+	return &encBase{data: d, parity: p, encode: em, gen: g}
+}

vendor/github.com/templexxx/xor/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2017 Temple3x
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/templexxx/xor/README.md

@@ -0,0 +1,48 @@
+# XOR
+
+XOR code engine in pure Go
+
+more than 10GB/S per core
+
+## Introduction:
+
+1. Use SIMD (SSE2 or AVX2) for speeding up
+2. ...
+
+## Installation
+To get the package use the standard:
+```bash
+go get github.com/templexxx/xor
+```
+
+## Documentation
+
+See the associated [GoDoc](http://godoc.org/github.com/templexxx/xor)
+
+
+## Performance
+
+Performance depends mainly on:
+
+1. SIMD extension
+2. unit size of worker
+3. hardware ( CPU RAM etc)
+
+Example of performance on my MacBook 2014-mid(i5-4278U 2.6GHz 2 physical cores). The 16MB per shards.
+```
+speed = ( shards * size ) / cost
+```
+| data_shards    | shard_size |speed (MB/S) |
+|----------|----|-----|
+| 2       |1KB|64127.95  |
+|2|1400B|59657.55|
+|2|16KB|35370.84|
+| 2       | 16MB|12128.95 |
+| 5       |1KB| 78837.33 |
+|5|1400B|58054.89|
+|5|16KB|50161.19|
+|5| 16MB|12750.41|
+
+## Who is using this?
+
+1. https://github.com/xtaci/kcp-go -- A Production-Grade Reliable-UDP Library for golang

vendor/github.com/templexxx/xor/avx2_amd64.s

@@ -0,0 +1,438 @@
+#include "textflag.h"
+
+// addr of mem
+#define DST BX
+#define SRC SI
+#define SRC0 TMP4
+#define SRC1 TMP5
+
+// loop args
+// num of vect
+#define VECT CX
+#define LEN DX
+// pos of matrix
+#define POS R8
+
+// tmp store
+// num of vect or ...
+#define TMP1 R9
+// pos of matrix or ...
+#define TMP2 R10
+// store addr of data/parity or ...
+#define TMP3 R11
+#define TMP4 R12
+#define TMP5 R13
+#define TMP6 R14
+
+// func bytesAVX2mini(dst, src0, src1 []byte, size int)
+TEXT ·bytesAVX2mini(SB), NOSPLIT, $0
+	MOVQ  len+72(FP), LEN
+	CMPQ  LEN, $0
+	JE    ret
+	MOVQ  dst+0(FP), DST
+	MOVQ  src0+24(FP), SRC0
+	MOVQ  src1+48(FP), SRC1
+	TESTQ $31, LEN
+	JNZ   not_aligned
+
+aligned:
+	MOVQ $0, POS
+
+loop32b:
+	VMOVDQU (SRC0)(POS*1), Y0
+	VPXOR   (SRC1)(POS*1), Y0, Y0
+	VMOVDQU Y0, (DST)(POS*1)
+	ADDQ    $32, POS
+	CMPQ    LEN, POS
+	JNE     loop32b
+	VZEROUPPER
+	RET
+
+loop_1b:
+	MOVB  -1(SRC0)(LEN*1), TMP1
+	MOVB  -1(SRC1)(LEN*1), TMP2
+	XORB  TMP1, TMP2
+	MOVB  TMP2, -1(DST)(LEN*1)
+	SUBQ  $1, LEN
+	TESTQ $7, LEN
+	JNZ   loop_1b
+	CMPQ  LEN, $0
+	JE    ret
+	TESTQ $31, LEN
+	JZ    aligned
+
+not_aligned:
+	TESTQ $7, LEN
+	JNE   loop_1b
+	MOVQ  LEN, TMP1
+	ANDQ  $31, TMP1
+
+loop_8b:
+	MOVQ -8(SRC0)(LEN*1), TMP2
+	MOVQ -8(SRC1)(LEN*1), TMP3
+	XORQ TMP2, TMP3
+	MOVQ TMP3, -8(DST)(LEN*1)
+	SUBQ $8, LEN
+	SUBQ $8, TMP1
+	JG   loop_8b
+
+	CMPQ LEN, $32
+	JGE  aligned
+	RET
+
+ret:
+	RET
+
+// func bytesAVX2small(dst, src0, src1 []byte, size int)
+TEXT ·bytesAVX2small(SB), NOSPLIT, $0
+	MOVQ  len+72(FP), LEN
+	CMPQ  LEN, $0
+	JE    ret
+	MOVQ  dst+0(FP), DST
+	MOVQ  src0+24(FP), SRC0
+	MOVQ  src1+48(FP), SRC1
+	TESTQ $127, LEN
+	JNZ   not_aligned
+
+aligned:
+	MOVQ $0, POS
+
+loop128b:
+	VMOVDQU (SRC0)(POS*1), Y0
+	VMOVDQU 32(SRC0)(POS*1), Y1
+	VMOVDQU 64(SRC0)(POS*1), Y2
+	VMOVDQU 96(SRC0)(POS*1), Y3
+	VPXOR   (SRC1)(POS*1), Y0, Y0
+	VPXOR   32(SRC1)(POS*1), Y1, Y1
+	VPXOR   64(SRC1)(POS*1), Y2, Y2
+	VPXOR   96(SRC1)(POS*1), Y3, Y3
+	VMOVDQU Y0, (DST)(POS*1)
+	VMOVDQU Y1, 32(DST)(POS*1)
+	VMOVDQU Y2, 64(DST)(POS*1)
+	VMOVDQU Y3, 96(DST)(POS*1)
+
+	ADDQ $128, POS
+	CMPQ LEN, POS
+	JNE  loop128b
+	VZEROUPPER
+	RET
+
+loop_1b:
+	MOVB  -1(SRC0)(LEN*1), TMP1
+	MOVB  -1(SRC1)(LEN*1), TMP2
+	XORB  TMP1, TMP2
+	MOVB  TMP2, -1(DST)(LEN*1)
+	SUBQ  $1, LEN
+	TESTQ $7, LEN
+	JNZ   loop_1b
+	CMPQ  LEN, $0
+	JE    ret
+	TESTQ $127, LEN
+	JZ    aligned
+
+not_aligned:
+	TESTQ $7, LEN
+	JNE   loop_1b
+	MOVQ  LEN, TMP1
+	ANDQ  $127, TMP1
+
+loop_8b:
+	MOVQ -8(SRC0)(LEN*1), TMP2
+	MOVQ -8(SRC1)(LEN*1), TMP3
+	XORQ TMP2, TMP3
+	MOVQ TMP3, -8(DST)(LEN*1)
+	SUBQ $8, LEN
+	SUBQ $8, TMP1
+	JG   loop_8b
+
+	CMPQ LEN, $128
+	JGE  aligned
+	RET
+
+ret:
+	RET
+
+// func bytesAVX2big(dst, src0, src1 []byte, size int)
+TEXT ·bytesAVX2big(SB), NOSPLIT, $0
+	MOVQ  len+72(FP), LEN
+	CMPQ  LEN, $0
+	JE    ret
+	MOVQ  dst+0(FP), DST
+	MOVQ  src0+24(FP), SRC0
+	MOVQ  src1+48(FP), SRC1
+	TESTQ $127, LEN
+	JNZ   not_aligned
+
+aligned:
+	MOVQ $0, POS
+
+loop128b:
+	VMOVDQU (SRC0)(POS*1), Y0
+	VMOVDQU 32(SRC0)(POS*1), Y1
+	VMOVDQU 64(SRC0)(POS*1), Y2
+	VMOVDQU 96(SRC0)(POS*1), Y3
+	VPXOR   (SRC1)(POS*1), Y0, Y0
+	VPXOR   32(SRC1)(POS*1), Y1, Y1
+	VPXOR   64(SRC1)(POS*1), Y2, Y2
+	VPXOR   96(SRC1)(POS*1), Y3, Y3
+	LONG    $0xe77da1c4; WORD $0x0304
+	LONG    $0xe77da1c4; WORD $0x034c; BYTE $0x20
+	LONG    $0xe77da1c4; WORD $0x0354; BYTE $0x40
+	LONG    $0xe77da1c4; WORD $0x035c; BYTE $0x60
+
+	ADDQ $128, POS
+	CMPQ LEN, POS
+	JNE  loop128b
+	SFENCE
+	VZEROUPPER
+	RET
+
+loop_1b:
+	MOVB  -1(SRC0)(LEN*1), TMP1
+	MOVB  -1(SRC1)(LEN*1), TMP2
+	XORB  TMP1, TMP2
+	MOVB  TMP2, -1(DST)(LEN*1)
+	SUBQ  $1, LEN
+	TESTQ $7, LEN
+	JNZ   loop_1b
+	CMPQ  LEN, $0
+	JE    ret
+	TESTQ $127, LEN
+	JZ    aligned
+
+not_aligned:
+	TESTQ $7, LEN
+	JNE   loop_1b
+	MOVQ  LEN, TMP1
+	ANDQ  $127, TMP1
+
+loop_8b:
+	MOVQ -8(SRC0)(LEN*1), TMP2
+	MOVQ -8(SRC1)(LEN*1), TMP3
+	XORQ TMP2, TMP3
+	MOVQ TMP3, -8(DST)(LEN*1)
+	SUBQ $8, LEN
+	SUBQ $8, TMP1
+	JG   loop_8b
+
+	CMPQ LEN, $128
+	JGE  aligned
+	RET
+
+ret:
+	RET
+
+// func matrixAVX2small(dst []byte, src [][]byte)
+TEXT ·matrixAVX2small(SB), NOSPLIT, $0
+	MOVQ  dst+0(FP), DST
+	MOVQ  src+24(FP), SRC
+	MOVQ  vec+32(FP), VECT
+	MOVQ  len+8(FP), LEN
+	TESTQ $127, LEN
+	JNZ   not_aligned
+
+aligned:
+	MOVQ $0, POS
+
+loop128b:
+	MOVQ    VECT, TMP1
+	SUBQ    $2, TMP1
+	MOVQ    $0, TMP2
+	MOVQ    (SRC)(TMP2*1), TMP3
+	MOVQ    TMP3, TMP4
+	VMOVDQU (TMP3)(POS*1), Y0
+	VMOVDQU 32(TMP4)(POS*1), Y1
+	VMOVDQU 64(TMP3)(POS*1), Y2
+	VMOVDQU 96(TMP4)(POS*1), Y3
+
+next_vect:
+	ADDQ    $24, TMP2
+	MOVQ    (SRC)(TMP2*1), TMP3
+	MOVQ    TMP3, TMP4
+	VMOVDQU (TMP3)(POS*1), Y4
+	VMOVDQU 32(TMP4)(POS*1), Y5
+	VMOVDQU 64(TMP3)(POS*1), Y6
+	VMOVDQU 96(TMP4)(POS*1), Y7
+	VPXOR   Y4, Y0, Y0
+	VPXOR   Y5, Y1, Y1
+	VPXOR   Y6, Y2, Y2
+	VPXOR   Y7, Y3, Y3
+	SUBQ    $1, TMP1
+	JGE     next_vect
+
+	VMOVDQU Y0, (DST)(POS*1)
+	VMOVDQU Y1, 32(DST)(POS*1)
+	VMOVDQU Y2, 64(DST)(POS*1)
+	VMOVDQU Y3, 96(DST)(POS*1)
+
+	ADDQ $128, POS
+	CMPQ LEN, POS
+	JNE  loop128b
+	VZEROUPPER
+	RET
+
+loop_1b:
+	MOVQ VECT, TMP1
+	MOVQ $0, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	SUBQ $2, TMP1
+	MOVB -1(TMP3)(LEN*1), TMP5
+
+next_vect_1b:
+	ADDQ $24, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	MOVB -1(TMP3)(LEN*1), TMP6
+	XORB TMP6, TMP5
+	SUBQ $1, TMP1
+	JGE  next_vect_1b
+
+	MOVB  TMP5, -1(DST)(LEN*1)
+	SUBQ  $1, LEN
+	TESTQ $7, LEN
+	JNZ   loop_1b
+
+	CMPQ  LEN, $0
+	JE    ret
+	TESTQ $127, LEN
+	JZ    aligned
+
+not_aligned:
+	TESTQ $7, LEN
+	JNE   loop_1b
+	MOVQ  LEN, TMP4
+	ANDQ  $127, TMP4
+
+loop_8b:
+	MOVQ VECT, TMP1
+	MOVQ $0, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	SUBQ $2, TMP1
+	MOVQ -8(TMP3)(LEN*1), TMP5
+
+next_vect_8b:
+	ADDQ $24, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	MOVQ -8(TMP3)(LEN*1), TMP6
+	XORQ TMP6, TMP5
+	SUBQ $1, TMP1
+	JGE  next_vect_8b
+
+	MOVQ TMP5, -8(DST)(LEN*1)
+	SUBQ $8, LEN
+	SUBQ $8, TMP4
+	JG   loop_8b
+
+	CMPQ LEN, $128
+	JGE  aligned
+	RET
+
+ret:
+	RET
+
+// func matrixAVX2big(dst []byte, src [][]byte)
+TEXT ·matrixAVX2big(SB), NOSPLIT, $0
+	MOVQ  dst+0(FP), DST
+	MOVQ  src+24(FP), SRC
+	MOVQ  vec+32(FP), VECT
+	MOVQ  len+8(FP), LEN
+	TESTQ $127, LEN
+	JNZ   not_aligned
+
+aligned:
+	MOVQ $0, POS
+
+loop128b:
+	MOVQ    VECT, TMP1
+	SUBQ    $2, TMP1
+	MOVQ    $0, TMP2
+	MOVQ    (SRC)(TMP2*1), TMP3
+	MOVQ    TMP3, TMP4
+	VMOVDQU (TMP3)(POS*1), Y0
+	VMOVDQU 32(TMP4)(POS*1), Y1
+	VMOVDQU 64(TMP3)(POS*1), Y2
+	VMOVDQU 96(TMP4)(POS*1), Y3
+
+next_vect:
+	ADDQ    $24, TMP2
+	MOVQ    (SRC)(TMP2*1), TMP3
+	MOVQ    TMP3, TMP4
+	VMOVDQU (TMP3)(POS*1), Y4
+	VMOVDQU 32(TMP4)(POS*1), Y5
+	VMOVDQU 64(TMP3)(POS*1), Y6
+	VMOVDQU 96(TMP4)(POS*1), Y7
+	VPXOR   Y4, Y0, Y0
+	VPXOR   Y5, Y1, Y1
+	VPXOR   Y6, Y2, Y2
+	VPXOR   Y7, Y3, Y3
+	SUBQ    $1, TMP1
+	JGE     next_vect
+
+	LONG $0xe77da1c4; WORD $0x0304             // VMOVNTDQ  go1.8 has
+	LONG $0xe77da1c4; WORD $0x034c; BYTE $0x20
+	LONG $0xe77da1c4; WORD $0x0354; BYTE $0x40
+	LONG $0xe77da1c4; WORD $0x035c; BYTE $0x60
+
+	ADDQ $128, POS
+	CMPQ LEN, POS
+	JNE  loop128b
+	VZEROUPPER
+	RET
+
+loop_1b:
+	MOVQ VECT, TMP1
+	MOVQ $0, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	SUBQ $2, TMP1
+	MOVB -1(TMP3)(LEN*1), TMP5
+
+next_vect_1b:
+	ADDQ $24, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	MOVB -1(TMP3)(LEN*1), TMP6
+	XORB TMP6, TMP5
+	SUBQ $1, TMP1
+	JGE  next_vect_1b
+
+	MOVB  TMP5, -1(DST)(LEN*1)
+	SUBQ  $1, LEN
+	TESTQ $7, LEN
+	JNZ   loop_1b
+
+	CMPQ  LEN, $0
+	JE    ret
+	TESTQ $127, LEN
+	JZ    aligned
+
+not_aligned:
+	TESTQ $7, LEN
+	JNE   loop_1b
+	MOVQ  LEN, TMP4
+	ANDQ  $127, TMP4
+
+loop_8b:
+	MOVQ VECT, TMP1
+	MOVQ $0, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	SUBQ $2, TMP1
+	MOVQ -8(TMP3)(LEN*1), TMP5
+
+next_vect_8b:
+	ADDQ $24, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	MOVQ -8(TMP3)(LEN*1), TMP6
+	XORQ TMP6, TMP5
+	SUBQ $1, TMP1
+	JGE  next_vect_8b
+
+	MOVQ TMP5, -8(DST)(LEN*1)
+	SUBQ $8, LEN
+	SUBQ $8, TMP4
+	JG   loop_8b
+
+	CMPQ LEN, $128
+	JGE  aligned
+	RET
+
+ret:
+	RET
+

vendor/github.com/templexxx/xor/nosimd.go

@@ -0,0 +1,116 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package xor
+
+import (
+	"runtime"
+	"unsafe"
+)
+
+const wordSize = int(unsafe.Sizeof(uintptr(0)))
+const supportsUnaligned = runtime.GOARCH == "386" || runtime.GOARCH == "amd64" || runtime.GOARCH == "ppc64" || runtime.GOARCH == "ppc64le" || runtime.GOARCH == "s390x"
+
+// xor the bytes in a and b. The destination is assumed to have enough space.
+func bytesNoSIMD(dst, a, b []byte, size int) {
+	if supportsUnaligned {
+		fastXORBytes(dst, a, b, size)
+	} else {
+		// TODO(hanwen): if (dst, a, b) have common alignment
+		// we could still try fastXORBytes. It is not clear
+		// how often this happens, and it's only worth it if
+		// the block encryption itself is hardware
+		// accelerated.
+		safeXORBytes(dst, a, b, size)
+	}
+}
+
+// split slice for cache-friendly
+const unitSize = 16 * 1024
+
+func matrixNoSIMD(dst []byte, src [][]byte) {
+	size := len(src[0])
+	start := 0
+	do := unitSize
+	for start < size {
+		end := start + do
+		if end <= size {
+			partNoSIMD(start, end, dst, src)
+			start = start + do
+		} else {
+			partNoSIMD(start, size, dst, src)
+			start = size
+		}
+	}
+}
+
+// split vect will improve performance with big data by reducing cache pollution
+func partNoSIMD(start, end int, dst []byte, src [][]byte) {
+	bytesNoSIMD(dst[start:end], src[0][start:end], src[1][start:end], end-start)
+	for i := 2; i < len(src); i++ {
+		bytesNoSIMD(dst[start:end], dst[start:end], src[i][start:end], end-start)
+	}
+}
+
+// fastXORBytes xor in bulk. It only works on architectures that
+// support unaligned read/writes.
+func fastXORBytes(dst, a, b []byte, n int) {
+	w := n / wordSize
+	if w > 0 {
+		wordBytes := w * wordSize
+		fastXORWords(dst[:wordBytes], a[:wordBytes], b[:wordBytes])
+	}
+	for i := n - n%wordSize; i < n; i++ {
+		dst[i] = a[i] ^ b[i]
+	}
+}
+
+func safeXORBytes(dst, a, b []byte, n int) {
+	ex := n % 8
+	for i := 0; i < ex; i++ {
+		dst[i] = a[i] ^ b[i]
+	}
+
+	for i := ex; i < n; i += 8 {
+		_dst := dst[i : i+8]
+		_a := a[i : i+8]
+		_b := b[i : i+8]
+		_dst[0] = _a[0] ^ _b[0]
+		_dst[1] = _a[1] ^ _b[1]
+		_dst[2] = _a[2] ^ _b[2]
+		_dst[3] = _a[3] ^ _b[3]
+
+		_dst[4] = _a[4] ^ _b[4]
+		_dst[5] = _a[5] ^ _b[5]
+		_dst[6] = _a[6] ^ _b[6]
+		_dst[7] = _a[7] ^ _b[7]
+	}
+}
+
+// fastXORWords XORs multiples of 4 or 8 bytes (depending on architecture.)
+// The arguments are assumed to be of equal length.
+func fastXORWords(dst, a, b []byte) {
+	dw := *(*[]uintptr)(unsafe.Pointer(&dst))
+	aw := *(*[]uintptr)(unsafe.Pointer(&a))
+	bw := *(*[]uintptr)(unsafe.Pointer(&b))
+	n := len(b) / wordSize
+	ex := n % 8
+	for i := 0; i < ex; i++ {
+		dw[i] = aw[i] ^ bw[i]
+	}
+
+	for i := ex; i < n; i += 8 {
+		_dw := dw[i : i+8]
+		_aw := aw[i : i+8]
+		_bw := bw[i : i+8]
+		_dw[0] = _aw[0] ^ _bw[0]
+		_dw[1] = _aw[1] ^ _bw[1]
+		_dw[2] = _aw[2] ^ _bw[2]
+		_dw[3] = _aw[3] ^ _bw[3]
+		_dw[4] = _aw[4] ^ _bw[4]
+		_dw[5] = _aw[5] ^ _bw[5]
+		_dw[6] = _aw[6] ^ _bw[6]
+		_dw[7] = _aw[7] ^ _bw[7]
+	}
+}

vendor/github.com/templexxx/xor/sse2_amd64.s

@@ -0,0 +1,574 @@
+#include "textflag.h"
+
+// addr of mem
+#define DST BX
+#define SRC SI
+#define SRC0 TMP4
+#define SRC1 TMP5
+
+// loop args
+// num of vect
+#define VECT CX
+#define LEN DX
+// pos of matrix
+#define POS R8
+
+// tmp store
+// num of vect or ...
+#define TMP1 R9
+// pos of matrix or ...
+#define TMP2 R10
+// store addr of data/parity or ...
+#define TMP3 R11
+#define TMP4 R12
+#define TMP5 R13
+#define TMP6 R14
+
+// func bytesSrc0(dst, src0, src1 []byte)
+TEXT ·xorSrc0(SB), NOSPLIT, $0
+	MOVQ  len+32(FP), LEN
+	CMPQ  LEN, $0
+	JE    ret
+	MOVQ  dst+0(FP), DST
+	MOVQ  src0+24(FP), SRC0
+	MOVQ  src1+48(FP), SRC1
+	TESTQ $15, LEN
+	JNZ   not_aligned
+
+aligned:
+	MOVQ $0, POS
+
+loop16b:
+	MOVOU (SRC0)(POS*1), X0
+	XORPD (SRC1)(POS*1), X0
+	MOVOU X0, (DST)(POS*1)
+	ADDQ  $16, POS
+	CMPQ  LEN, POS
+	JNE   loop16b
+	RET
+
+loop_1b:
+	MOVB  -1(SRC0)(LEN*1), TMP1
+	MOVB  -1(SRC1)(LEN*1), TMP2
+	XORB  TMP1, TMP2
+	MOVB  TMP2, -1(DST)(LEN*1)
+	SUBQ  $1, LEN
+	TESTQ $7, LEN
+	JNZ   loop_1b
+	CMPQ  LEN, $0
+	JE    ret
+	TESTQ $15, LEN
+	JZ    aligned
+
+not_aligned:
+	TESTQ $7, LEN
+	JNE   loop_1b
+	MOVQ  LEN, TMP1
+	ANDQ  $15, TMP1
+
+loop_8b:
+	MOVQ -8(SRC0)(LEN*1), TMP2
+	MOVQ -8(SRC1)(LEN*1), TMP3
+	XORQ TMP2, TMP3
+	MOVQ TMP3, -8(DST)(LEN*1)
+	SUBQ $8, LEN
+	SUBQ $8, TMP1
+	JG   loop_8b
+
+	CMPQ LEN, $16
+	JGE  aligned
+	RET
+
+ret:
+	RET
+
+// func bytesSrc1(dst, src0, src1 []byte)
+TEXT ·xorSrc1(SB), NOSPLIT, $0
+	MOVQ  len+56(FP), LEN
+	CMPQ  LEN, $0
+	JE    ret
+	MOVQ  dst+0(FP), DST
+	MOVQ  src0+24(FP), SRC0
+	MOVQ  src1+48(FP), SRC1
+	TESTQ $15, LEN
+	JNZ   not_aligned
+
+aligned:
+	MOVQ $0, POS
+
+loop16b:
+	MOVOU (SRC0)(POS*1), X0
+	XORPD (SRC1)(POS*1), X0
+	MOVOU X0, (DST)(POS*1)
+	ADDQ  $16, POS
+	CMPQ  LEN, POS
+	JNE   loop16b
+	RET
+
+loop_1b:
+	MOVB  -1(SRC0)(LEN*1), TMP1
+	MOVB  -1(SRC1)(LEN*1), TMP2
+	XORB  TMP1, TMP2
+	MOVB  TMP2, -1(DST)(LEN*1)
+	SUBQ  $1, LEN
+	TESTQ $7, LEN
+	JNZ   loop_1b
+	CMPQ  LEN, $0
+	JE    ret
+	TESTQ $15, LEN
+	JZ    aligned
+
+not_aligned:
+	TESTQ $7, LEN
+	JNE   loop_1b
+	MOVQ  LEN, TMP1
+	ANDQ  $15, TMP1
+
+loop_8b:
+	MOVQ -8(SRC0)(LEN*1), TMP2
+	MOVQ -8(SRC1)(LEN*1), TMP3
+	XORQ TMP2, TMP3
+	MOVQ TMP3, -8(DST)(LEN*1)
+	SUBQ $8, LEN
+	SUBQ $8, TMP1
+	JG   loop_8b
+
+	CMPQ LEN, $16
+	JGE  aligned
+	RET
+
+ret:
+	RET
+
+// func bytesSSE2mini(dst, src0, src1 []byte, size int)
+TEXT ·bytesSSE2mini(SB), NOSPLIT, $0
+	MOVQ  len+72(FP), LEN
+	CMPQ  LEN, $0
+	JE    ret
+	MOVQ  dst+0(FP), DST
+	MOVQ  src0+24(FP), SRC0
+	MOVQ  src1+48(FP), SRC1
+	TESTQ $15, LEN
+	JNZ   not_aligned
+
+aligned:
+	MOVQ $0, POS
+
+loop16b:
+	MOVOU (SRC0)(POS*1), X0
+	XORPD (SRC1)(POS*1), X0
+
+	// MOVOU (SRC1)(POS*1), X4
+	// PXOR X4, X0
+	MOVOU X0, (DST)(POS*1)
+	ADDQ  $16, POS
+	CMPQ  LEN, POS
+	JNE   loop16b
+	RET
+
+loop_1b:
+	MOVB  -1(SRC0)(LEN*1), TMP1
+	MOVB  -1(SRC1)(LEN*1), TMP2
+	XORB  TMP1, TMP2
+	MOVB  TMP2, -1(DST)(LEN*1)
+	SUBQ  $1, LEN
+	TESTQ $7, LEN
+	JNZ   loop_1b
+	CMPQ  LEN, $0
+	JE    ret
+	TESTQ $15, LEN
+	JZ    aligned
+
+not_aligned:
+	TESTQ $7, LEN
+	JNE   loop_1b
+	MOVQ  LEN, TMP1
+	ANDQ  $15, TMP1
+
+loop_8b:
+	MOVQ -8(SRC0)(LEN*1), TMP2
+	MOVQ -8(SRC1)(LEN*1), TMP3
+	XORQ TMP2, TMP3
+	MOVQ TMP3, -8(DST)(LEN*1)
+	SUBQ $8, LEN
+	SUBQ $8, TMP1
+	JG   loop_8b
+
+	CMPQ LEN, $16
+	JGE  aligned
+	RET
+
+ret:
+	RET
+
+// func bytesSSE2small(dst, src0, src1 []byte, size int)
+TEXT ·bytesSSE2small(SB), NOSPLIT, $0
+	MOVQ  len+72(FP), LEN
+	CMPQ  LEN, $0
+	JE    ret
+	MOVQ  dst+0(FP), DST
+	MOVQ  src0+24(FP), SRC0
+	MOVQ  src1+48(FP), SRC1
+	TESTQ $63, LEN
+	JNZ   not_aligned
+
+aligned:
+	MOVQ $0, POS
+
+loop64b:
+	MOVOU (SRC0)(POS*1), X0
+	MOVOU 16(SRC0)(POS*1), X1
+	MOVOU 32(SRC0)(POS*1), X2
+	MOVOU 48(SRC0)(POS*1), X3
+
+	MOVOU (SRC1)(POS*1), X4
+	MOVOU 16(SRC1)(POS*1), X5
+	MOVOU 32(SRC1)(POS*1), X6
+	MOVOU 48(SRC1)(POS*1), X7
+
+	PXOR X4, X0
+	PXOR X5, X1
+	PXOR X6, X2
+	PXOR X7, X3
+
+	MOVOU X0, (DST)(POS*1)
+	MOVOU X1, 16(DST)(POS*1)
+	MOVOU X2, 32(DST)(POS*1)
+	MOVOU X3, 48(DST)(POS*1)
+
+	ADDQ $64, POS
+	CMPQ LEN, POS
+	JNE  loop64b
+	RET
+
+loop_1b:
+	MOVB  -1(SRC0)(LEN*1), TMP1
+	MOVB  -1(SRC1)(LEN*1), TMP2
+	XORB  TMP1, TMP2
+	MOVB  TMP2, -1(DST)(LEN*1)
+	SUBQ  $1, LEN
+	TESTQ $7, LEN
+	JNZ   loop_1b
+	CMPQ  LEN, $0
+	JE    ret
+	TESTQ $63, LEN
+	JZ    aligned
+
+not_aligned:
+	TESTQ $7, LEN
+	JNE   loop_1b
+	MOVQ  LEN, TMP1
+	ANDQ  $63, TMP1
+
+loop_8b:
+	MOVQ -8(SRC0)(LEN*1), TMP2
+	MOVQ -8(SRC1)(LEN*1), TMP3
+	XORQ TMP2, TMP3
+	MOVQ TMP3, -8(DST)(LEN*1)
+	SUBQ $8, LEN
+	SUBQ $8, TMP1
+	JG   loop_8b
+
+	CMPQ LEN, $64
+	JGE  aligned
+	RET
+
+ret:
+	RET
+
+// func bytesSSE2big(dst, src0, src1 []byte, size int)
+TEXT ·bytesSSE2big(SB), NOSPLIT, $0
+	MOVQ  len+72(FP), LEN
+	CMPQ  LEN, $0
+	JE    ret
+	MOVQ  dst+0(FP), DST
+	MOVQ  src0+24(FP), SRC0
+	MOVQ  src1+48(FP), SRC1
+	TESTQ $63, LEN
+	JNZ   not_aligned
+
+aligned:
+	MOVQ $0, POS
+
+loop64b:
+	MOVOU (SRC0)(POS*1), X0
+	MOVOU 16(SRC0)(POS*1), X1
+	MOVOU 32(SRC0)(POS*1), X2
+	MOVOU 48(SRC0)(POS*1), X3
+
+	MOVOU (SRC1)(POS*1), X4
+	MOVOU 16(SRC1)(POS*1), X5
+	MOVOU 32(SRC1)(POS*1), X6
+	MOVOU 48(SRC1)(POS*1), X7
+
+	PXOR X4, X0
+	PXOR X5, X1
+	PXOR X6, X2
+	PXOR X7, X3
+
+	LONG $0xe70f4266; WORD $0x0304             // MOVNTDQ
+	LONG $0xe70f4266; WORD $0x034c; BYTE $0x10
+	LONG $0xe70f4266; WORD $0x0354; BYTE $0x20
+	LONG $0xe70f4266; WORD $0x035c; BYTE $0x30
+
+	ADDQ $64, POS
+	CMPQ LEN, POS
+	JNE  loop64b
+	RET
+
+loop_1b:
+	MOVB  -1(SRC0)(LEN*1), TMP1
+	MOVB  -1(SRC1)(LEN*1), TMP2
+	XORB  TMP1, TMP2
+	MOVB  TMP2, -1(DST)(LEN*1)
+	SUBQ  $1, LEN
+	TESTQ $7, LEN
+	JNZ   loop_1b
+	CMPQ  LEN, $0
+	JE    ret
+	TESTQ $63, LEN
+	JZ    aligned
+
+not_aligned:
+	TESTQ $7, LEN
+	JNE   loop_1b
+	MOVQ  LEN, TMP1
+	ANDQ  $63, TMP1
+
+loop_8b:
+	MOVQ -8(SRC0)(LEN*1), TMP2
+	MOVQ -8(SRC1)(LEN*1), TMP3
+	XORQ TMP2, TMP3
+	MOVQ TMP3, -8(DST)(LEN*1)
+	SUBQ $8, LEN
+	SUBQ $8, TMP1
+	JG   loop_8b
+
+	CMPQ LEN, $64
+	JGE  aligned
+	RET
+
+ret:
+	RET
+
+// func matrixSSE2small(dst []byte, src [][]byte)
+TEXT ·matrixSSE2small(SB), NOSPLIT, $0
+	MOVQ  dst+0(FP), DST
+	MOVQ  src+24(FP), SRC
+	MOVQ  vec+32(FP), VECT
+	MOVQ  len+8(FP), LEN
+	TESTQ $63, LEN
+	JNZ   not_aligned
+
+aligned:
+	MOVQ $0, POS
+
+loop64b:
+	MOVQ  VECT, TMP1
+	SUBQ  $2, TMP1
+	MOVQ  $0, TMP2
+	MOVQ  (SRC)(TMP2*1), TMP3
+	MOVQ  TMP3, TMP4
+	MOVOU (TMP3)(POS*1), X0
+	MOVOU 16(TMP4)(POS*1), X1
+	MOVOU 32(TMP3)(POS*1), X2
+	MOVOU 48(TMP4)(POS*1), X3
+
+next_vect:
+	ADDQ  $24, TMP2
+	MOVQ  (SRC)(TMP2*1), TMP3
+	MOVQ  TMP3, TMP4
+	MOVOU (TMP3)(POS*1), X4
+	MOVOU 16(TMP4)(POS*1), X5
+	MOVOU 32(TMP3)(POS*1), X6
+	MOVOU 48(TMP4)(POS*1), X7
+	PXOR  X4, X0
+	PXOR  X5, X1
+	PXOR  X6, X2
+	PXOR  X7, X3
+	SUBQ  $1, TMP1
+	JGE   next_vect
+
+	MOVOU X0, (DST)(POS*1)
+	MOVOU X1, 16(DST)(POS*1)
+	MOVOU X2, 32(DST)(POS*1)
+	MOVOU X3, 48(DST)(POS*1)
+
+	ADDQ $64, POS
+	CMPQ LEN, POS
+	JNE  loop64b
+	RET
+
+loop_1b:
+	MOVQ VECT, TMP1
+	MOVQ $0, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	SUBQ $2, TMP1
+	MOVB -1(TMP3)(LEN*1), TMP5
+
+next_vect_1b:
+	ADDQ $24, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	MOVB -1(TMP3)(LEN*1), TMP6
+	XORB TMP6, TMP5
+	SUBQ $1, TMP1
+	JGE  next_vect_1b
+
+	MOVB  TMP5, -1(DST)(LEN*1)
+	SUBQ  $1, LEN
+	TESTQ $7, LEN
+	JNZ   loop_1b
+
+	CMPQ  LEN, $0
+	JE    ret
+	TESTQ $63, LEN
+	JZ    aligned
+
+not_aligned:
+	TESTQ $7, LEN
+	JNE   loop_1b
+	MOVQ  LEN, TMP4
+	ANDQ  $63, TMP4
+
+loop_8b:
+	MOVQ VECT, TMP1
+	MOVQ $0, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	SUBQ $2, TMP1
+	MOVQ -8(TMP3)(LEN*1), TMP5
+
+next_vect_8b:
+	ADDQ $24, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	MOVQ -8(TMP3)(LEN*1), TMP6
+	XORQ TMP6, TMP5
+	SUBQ $1, TMP1
+	JGE  next_vect_8b
+
+	MOVQ TMP5, -8(DST)(LEN*1)
+	SUBQ $8, LEN
+	SUBQ $8, TMP4
+	JG   loop_8b
+
+	CMPQ LEN, $64
+	JGE  aligned
+	RET
+
+ret:
+	RET
+
+// func matrixSSE2big(dst []byte, src [][]byte)
+TEXT ·matrixSSE2big(SB), NOSPLIT, $0
+	MOVQ  dst+0(FP), DST
+	MOVQ  src+24(FP), SRC
+	MOVQ  vec+32(FP), VECT
+	MOVQ  len+8(FP), LEN
+	TESTQ $63, LEN
+	JNZ   not_aligned
+
+aligned:
+	MOVQ $0, POS
+
+loop64b:
+	MOVQ  VECT, TMP1
+	SUBQ  $2, TMP1
+	MOVQ  $0, TMP2
+	MOVQ  (SRC)(TMP2*1), TMP3
+	MOVQ  TMP3, TMP4
+	MOVOU (TMP3)(POS*1), X0
+	MOVOU 16(TMP4)(POS*1), X1
+	MOVOU 32(TMP3)(POS*1), X2
+	MOVOU 48(TMP4)(POS*1), X3
+
+next_vect:
+	ADDQ  $24, TMP2
+	MOVQ  (SRC)(TMP2*1), TMP3
+	MOVQ  TMP3, TMP4
+	MOVOU (TMP3)(POS*1), X4
+	MOVOU 16(TMP4)(POS*1), X5
+	MOVOU 32(TMP3)(POS*1), X6
+	MOVOU 48(TMP4)(POS*1), X7
+	PXOR  X4, X0
+	PXOR  X5, X1
+	PXOR  X6, X2
+	PXOR  X7, X3
+	SUBQ  $1, TMP1
+	JGE   next_vect
+
+	LONG $0xe70f4266; WORD $0x0304
+	LONG $0xe70f4266; WORD $0x034c; BYTE $0x10
+	LONG $0xe70f4266; WORD $0x0354; BYTE $0x20
+	LONG $0xe70f4266; WORD $0x035c; BYTE $0x30
+
+	ADDQ $64, POS
+	CMPQ LEN, POS
+	JNE  loop64b
+	RET
+
+loop_1b:
+	MOVQ VECT, TMP1
+	MOVQ $0, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	SUBQ $2, TMP1
+	MOVB -1(TMP3)(LEN*1), TMP5
+
+next_vect_1b:
+	ADDQ $24, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	MOVB -1(TMP3)(LEN*1), TMP6
+	XORB TMP6, TMP5
+	SUBQ $1, TMP1
+	JGE  next_vect_1b
+
+	MOVB  TMP5, -1(DST)(LEN*1)
+	SUBQ  $1, LEN
+	TESTQ $7, LEN
+	JNZ   loop_1b
+
+	CMPQ  LEN, $0
+	JE    ret
+	TESTQ $63, LEN
+	JZ    aligned
+
+not_aligned:
+	TESTQ $7, LEN
+	JNE   loop_1b
+	MOVQ  LEN, TMP4
+	ANDQ  $63, TMP4
+
+loop_8b:
+	MOVQ VECT, TMP1
+	MOVQ $0, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	SUBQ $2, TMP1
+	MOVQ -8(TMP3)(LEN*1), TMP5
+
+next_vect_8b:
+	ADDQ $24, TMP2
+	MOVQ (SRC)(TMP2*1), TMP3
+	MOVQ -8(TMP3)(LEN*1), TMP6
+	XORQ TMP6, TMP5
+	SUBQ $1, TMP1
+	JGE  next_vect_8b
+
+	MOVQ TMP5, -8(DST)(LEN*1)
+	SUBQ $8, LEN
+	SUBQ $8, TMP4
+	JG   loop_8b
+
+	CMPQ LEN, $64
+	JGE  aligned
+	RET
+
+ret:
+	RET
+
+TEXT ·hasSSE2(SB), NOSPLIT, $0
+	XORQ AX, AX
+	INCL AX
+	CPUID
+	SHRQ $26, DX
+	ANDQ $1, DX
+	MOVB DX, ret+0(FP)
+	RET
+

vendor/github.com/templexxx/xor/xor.go

@@ -0,0 +1,49 @@
+package xor
+
+// SIMD Extensions
+const (
+	none = iota
+	avx2
+	// first introduced by Intel with the initial version of the Pentium 4 in 2001
+	// so I think we can assume all amd64 has sse2
+	sse2
+)
+
+var extension = none
+
+// Bytes : chose the shortest one as xor size
+// it's better to use it for big data ( > 64bytes )
+func Bytes(dst, src0, src1 []byte) {
+	size := len(dst)
+	if size > len(src0) {
+		size = len(src0)
+	}
+	if size > len(src1) {
+		size = len(src1)
+	}
+	xorBytes(dst, src0, src1, size)
+}
+
+// BytesSameLen : all slice's length must be equal
+// cut size branch, save time for small data
+func BytesSameLen(dst, src0, src1 []byte) {
+	xorSrc1(dst, src0, src1)
+}
+
+// BytesSrc0 : src1 >= src0, dst >= src0
+// xor src0's len bytes
+func BytesSrc0(dst, src0, src1 []byte) {
+	xorSrc0(dst, src0, src1)
+}
+
+// BytesSrc1 : src0 >= src1, dst >= src1
+// xor src1's len bytes
+func BytesSrc1(dst, src0, src1 []byte) {
+	xorSrc1(dst, src0, src1)
+}
+
+// Matrix : all slice's length must be equal && != 0
+// len(src) must >= 2
+func Matrix(dst []byte, src [][]byte) {
+	xorMatrix(dst, src)
+}

vendor/github.com/templexxx/xor/xor_amd64.go

@@ -0,0 +1,120 @@
+package xor
+
+import "github.com/templexxx/cpufeat"
+
+func init() {
+	getEXT()
+}
+
+func getEXT() {
+	if cpufeat.X86.HasAVX2 {
+		extension = avx2
+	} else {
+		extension = sse2
+	}
+	return
+}
+
+func xorBytes(dst, src0, src1 []byte, size int) {
+	switch extension {
+	case avx2:
+		bytesAVX2(dst, src0, src1, size)
+	default:
+		bytesSSE2(dst, src0, src1, size)
+	}
+}
+
+// non-temporal hint store
+const nontmp = 8 * 1024
+const avx2loopsize = 128
+
+func bytesAVX2(dst, src0, src1 []byte, size int) {
+	if size < avx2loopsize {
+		bytesAVX2mini(dst, src0, src1, size)
+	} else if size >= avx2loopsize && size <= nontmp {
+		bytesAVX2small(dst, src0, src1, size)
+	} else {
+		bytesAVX2big(dst, src0, src1, size)
+	}
+}
+
+const sse2loopsize = 64
+
+func bytesSSE2(dst, src0, src1 []byte, size int) {
+	if size < sse2loopsize {
+		bytesSSE2mini(dst, src0, src1, size)
+	} else if size >= sse2loopsize && size <= nontmp {
+		bytesSSE2small(dst, src0, src1, size)
+	} else {
+		bytesSSE2big(dst, src0, src1, size)
+	}
+}
+
+func xorMatrix(dst []byte, src [][]byte) {
+	switch extension {
+	case avx2:
+		matrixAVX2(dst, src)
+	default:
+		matrixSSE2(dst, src)
+	}
+}
+
+func matrixAVX2(dst []byte, src [][]byte) {
+	size := len(dst)
+	if size > nontmp {
+		matrixAVX2big(dst, src)
+	} else {
+		matrixAVX2small(dst, src)
+	}
+}
+
+func matrixSSE2(dst []byte, src [][]byte) {
+	size := len(dst)
+	if size > nontmp {
+		matrixSSE2big(dst, src)
+	} else {
+		matrixSSE2small(dst, src)
+	}
+}
+
+//go:noescape
+func xorSrc0(dst, src0, src1 []byte)
+
+//go:noescape
+func xorSrc1(dst, src0, src1 []byte)
+
+//go:noescape
+func bytesAVX2mini(dst, src0, src1 []byte, size int)
+
+//go:noescape
+func bytesAVX2big(dst, src0, src1 []byte, size int)
+
+//go:noescape
+func bytesAVX2small(dst, src0, src1 []byte, size int)
+
+//go:noescape
+func bytesSSE2mini(dst, src0, src1 []byte, size int)
+
+//go:noescape
+func bytesSSE2small(dst, src0, src1 []byte, size int)
+
+//go:noescape
+func bytesSSE2big(dst, src0, src1 []byte, size int)
+
+//go:noescape
+func matrixAVX2small(dst []byte, src [][]byte)
+
+//go:noescape
+func matrixAVX2big(dst []byte, src [][]byte)
+
+//go:noescape
+func matrixSSE2small(dst []byte, src [][]byte)
+
+//go:noescape
+func matrixSSE2big(dst []byte, src [][]byte)
+
+//go:noescape
+func hasAVX2() bool
+
+//go:noescape
+func hasSSE2() bool

vendor/github.com/templexxx/xor/xor_other.go

@@ -0,0 +1,19 @@
+// +build !amd64 noasm
+
+package xor
+
+func xorBytes(dst, src0, src1 []byte, size int) {
+	bytesNoSIMD(dst, src0, src1, size)
+}
+
+func xorMatrix(dst []byte, src [][]byte) {
+	matrixNoSIMD(dst, src)
+}
+
+func xorSrc0(dst, src0, src1 []byte) {
+	bytesNoSIMD(dst, src0, src1, len(src0))
+}
+
+func xorSrc1(dst, src0, src1 []byte) {
+	bytesNoSIMD(dst, src0, src1, len(src1))
+}

vendor/github.com/tjfoc/gmsm/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
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+      and distribution as defined by Sections 1 through 9 of this document.
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+
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+      other entities that control, are controlled by, or are under common
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+      direction or management of such entity, whether by contract or
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+
+      "You" (or "Your") shall mean an individual or Legal Entity
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+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
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+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
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+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
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+   7. Disclaimer of Warranty. Unless required by applicable law or
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+      Contributor provides its Contributions) on an "AS IS" BASIS,
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+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
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+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/tjfoc/gmsm/sm4/sm4.go

@@ -0,0 +1,342 @@
+/*
+Copyright Suzhou Tongji Fintech Research Institute 2017 All Rights Reserved.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+                 http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+sm4 acceration
+modified by Jack, 2017 Oct
+*/
+
+package sm4
+
+import (
+	"crypto/cipher"
+	"crypto/rand"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"io/ioutil"
+	"os"
+	"strconv"
+)
+
+const BlockSize = 16
+
+type SM4Key []byte
+
+type KeySizeError int
+
+// Cipher is an instance of SM4 encryption.
+type Sm4Cipher struct {
+	subkeys []uint32
+	block1  []uint32
+	block2  []byte
+}
+
+// sm4密钥参量
+var fk = [4]uint32{
+	0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc,
+}
+
+// sm4密钥参量
+var ck = [32]uint32{
+	0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,
+	0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9,
+	0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249,
+	0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,
+	0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,
+	0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,
+	0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209,
+	0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279,
+}
+
+// sm4密钥参量
+var sbox = [256]uint8{
+	0xd6, 0x90, 0xe9, 0xfe, 0xcc, 0xe1, 0x3d, 0xb7, 0x16, 0xb6, 0x14, 0xc2, 0x28, 0xfb, 0x2c, 0x05,
+	0x2b, 0x67, 0x9a, 0x76, 0x2a, 0xbe, 0x04, 0xc3, 0xaa, 0x44, 0x13, 0x26, 0x49, 0x86, 0x06, 0x99,
+	0x9c, 0x42, 0x50, 0xf4, 0x91, 0xef, 0x98, 0x7a, 0x33, 0x54, 0x0b, 0x43, 0xed, 0xcf, 0xac, 0x62,
+	0xe4, 0xb3, 0x1c, 0xa9, 0xc9, 0x08, 0xe8, 0x95, 0x80, 0xdf, 0x94, 0xfa, 0x75, 0x8f, 0x3f, 0xa6,
+	0x47, 0x07, 0xa7, 0xfc, 0xf3, 0x73, 0x17, 0xba, 0x83, 0x59, 0x3c, 0x19, 0xe6, 0x85, 0x4f, 0xa8,
+	0x68, 0x6b, 0x81, 0xb2, 0x71, 0x64, 0xda, 0x8b, 0xf8, 0xeb, 0x0f, 0x4b, 0x70, 0x56, 0x9d, 0x35,
+	0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, 0xd1, 0xa2, 0x25, 0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, 0x87,
+	0xd4, 0x00, 0x46, 0x57, 0x9f, 0xd3, 0x27, 0x52, 0x4c, 0x36, 0x02, 0xe7, 0xa0, 0xc4, 0xc8, 0x9e,
+	0xea, 0xbf, 0x8a, 0xd2, 0x40, 0xc7, 0x38, 0xb5, 0xa3, 0xf7, 0xf2, 0xce, 0xf9, 0x61, 0x15, 0xa1,
+	0xe0, 0xae, 0x5d, 0xa4, 0x9b, 0x34, 0x1a, 0x55, 0xad, 0x93, 0x32, 0x30, 0xf5, 0x8c, 0xb1, 0xe3,
+	0x1d, 0xf6, 0xe2, 0x2e, 0x82, 0x66, 0xca, 0x60, 0xc0, 0x29, 0x23, 0xab, 0x0d, 0x53, 0x4e, 0x6f,
+	0xd5, 0xdb, 0x37, 0x45, 0xde, 0xfd, 0x8e, 0x2f, 0x03, 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b, 0x51,
+	0x8d, 0x1b, 0xaf, 0x92, 0xbb, 0xdd, 0xbc, 0x7f, 0x11, 0xd9, 0x5c, 0x41, 0x1f, 0x10, 0x5a, 0xd8,
+	0x0a, 0xc1, 0x31, 0x88, 0xa5, 0xcd, 0x7b, 0xbd, 0x2d, 0x74, 0xd0, 0x12, 0xb8, 0xe5, 0xb4, 0xb0,
+	0x89, 0x69, 0x97, 0x4a, 0x0c, 0x96, 0x77, 0x7e, 0x65, 0xb9, 0xf1, 0x09, 0xc5, 0x6e, 0xc6, 0x84,
+	0x18, 0xf0, 0x7d, 0xec, 0x3a, 0xdc, 0x4d, 0x20, 0x79, 0xee, 0x5f, 0x3e, 0xd7, 0xcb, 0x39, 0x48,
+}
+
+var sbox0 = [256]uint32{
+	0xd55b5b8e, 0x924242d0, 0xeaa7a74d, 0xfdfbfb06, 0xcf3333fc, 0xe2878765, 0x3df4f4c9, 0xb5dede6b, 0x1658584e, 0xb4dada6e, 0x14505044, 0xc10b0bca, 0x28a0a088, 0xf8efef17, 0x2cb0b09c, 0x05141411,
+	0x2bacac87, 0x669d9dfb, 0x986a6af2, 0x77d9d9ae, 0x2aa8a882, 0xbcfafa46, 0x04101014, 0xc00f0fcf, 0xa8aaaa02, 0x45111154, 0x134c4c5f, 0x269898be, 0x4825256d, 0x841a1a9e, 0x0618181e, 0x9b6666fd,
+	0x9e7272ec, 0x4309094a, 0x51414110, 0xf7d3d324, 0x934646d5, 0xecbfbf53, 0x9a6262f8, 0x7be9e992, 0x33ccccff, 0x55515104, 0x0b2c2c27, 0x420d0d4f, 0xeeb7b759, 0xcc3f3ff3, 0xaeb2b21c, 0x638989ea,
+	0xe7939374, 0xb1cece7f, 0x1c70706c, 0xaba6a60d, 0xca2727ed, 0x08202028, 0xeba3a348, 0x975656c1, 0x82020280, 0xdc7f7fa3, 0x965252c4, 0xf9ebeb12, 0x74d5d5a1, 0x8d3e3eb3, 0x3ffcfcc3, 0xa49a9a3e,
+	0x461d1d5b, 0x071c1c1b, 0xa59e9e3b, 0xfff3f30c, 0xf0cfcf3f, 0x72cdcdbf, 0x175c5c4b, 0xb8eaea52, 0x810e0e8f, 0x5865653d, 0x3cf0f0cc, 0x1964647d, 0xe59b9b7e, 0x87161691, 0x4e3d3d73, 0xaaa2a208,
+	0x69a1a1c8, 0x6aadadc7, 0x83060685, 0xb0caca7a, 0x70c5c5b5, 0x659191f4, 0xd96b6bb2, 0x892e2ea7, 0xfbe3e318, 0xe8afaf47, 0x0f3c3c33, 0x4a2d2d67, 0x71c1c1b0, 0x5759590e, 0x9f7676e9, 0x35d4d4e1,
+	0x1e787866, 0x249090b4, 0x0e383836, 0x5f797926, 0x628d8def, 0x59616138, 0xd2474795, 0xa08a8a2a, 0x259494b1, 0x228888aa, 0x7df1f18c, 0x3bececd7, 0x01040405, 0x218484a5, 0x79e1e198, 0x851e1e9b,
+	0xd7535384, 0x00000000, 0x4719195e, 0x565d5d0b, 0x9d7e7ee3, 0xd04f4f9f, 0x279c9cbb, 0x5349491a, 0x4d31317c, 0x36d8d8ee, 0x0208080a, 0xe49f9f7b, 0xa2828220, 0xc71313d4, 0xcb2323e8, 0x9c7a7ae6,
+	0xe9abab42, 0xbdfefe43, 0x882a2aa2, 0xd14b4b9a, 0x41010140, 0xc41f1fdb, 0x38e0e0d8, 0xb7d6d661, 0xa18e8e2f, 0xf4dfdf2b, 0xf1cbcb3a, 0xcd3b3bf6, 0xfae7e71d, 0x608585e5, 0x15545441, 0xa3868625,
+	0xe3838360, 0xacbaba16, 0x5c757529, 0xa6929234, 0x996e6ef7, 0x34d0d0e4, 0x1a686872, 0x54555501, 0xafb6b619, 0x914e4edf, 0x32c8c8fa, 0x30c0c0f0, 0xf6d7d721, 0x8e3232bc, 0xb3c6c675, 0xe08f8f6f,
+	0x1d747469, 0xf5dbdb2e, 0xe18b8b6a, 0x2eb8b896, 0x800a0a8a, 0x679999fe, 0xc92b2be2, 0x618181e0, 0xc30303c0, 0x29a4a48d, 0x238c8caf, 0xa9aeae07, 0x0d343439, 0x524d4d1f, 0x4f393976, 0x6ebdbdd3,
+	0xd6575781, 0xd86f6fb7, 0x37dcdceb, 0x44151551, 0xdd7b7ba6, 0xfef7f709, 0x8c3a3ab6, 0x2fbcbc93, 0x030c0c0f, 0xfcffff03, 0x6ba9a9c2, 0x73c9c9ba, 0x6cb5b5d9, 0x6db1b1dc, 0x5a6d6d37, 0x50454515,
+	0x8f3636b9, 0x1b6c6c77, 0xadbebe13, 0x904a4ada, 0xb9eeee57, 0xde7777a9, 0xbef2f24c, 0x7efdfd83, 0x11444455, 0xda6767bd, 0x5d71712c, 0x40050545, 0x1f7c7c63, 0x10404050, 0x5b696932, 0xdb6363b8,
+	0x0a282822, 0xc20707c5, 0x31c4c4f5, 0x8a2222a8, 0xa7969631, 0xce3737f9, 0x7aeded97, 0xbff6f649, 0x2db4b499, 0x75d1d1a4, 0xd3434390, 0x1248485a, 0xbae2e258, 0xe6979771, 0xb6d2d264, 0xb2c2c270,
+	0x8b2626ad, 0x68a5a5cd, 0x955e5ecb, 0x4b292962, 0x0c30303c, 0x945a5ace, 0x76ddddab, 0x7ff9f986, 0x649595f1, 0xbbe6e65d, 0xf2c7c735, 0x0924242d, 0xc61717d1, 0x6fb9b9d6, 0xc51b1bde, 0x86121294,
+	0x18606078, 0xf3c3c330, 0x7cf5f589, 0xefb3b35c, 0x3ae8e8d2, 0xdf7373ac, 0x4c353579, 0x208080a0, 0x78e5e59d, 0xedbbbb56, 0x5e7d7d23, 0x3ef8f8c6, 0xd45f5f8b, 0xc82f2fe7, 0x39e4e4dd, 0x49212168,
+}
+
+var sbox1 = [256]uint32{
+	0x5b5b8ed5, 0x4242d092, 0xa7a74dea, 0xfbfb06fd, 0x3333fccf, 0x878765e2, 0xf4f4c93d, 0xdede6bb5, 0x58584e16, 0xdada6eb4, 0x50504414, 0x0b0bcac1, 0xa0a08828, 0xefef17f8, 0xb0b09c2c, 0x14141105,
+	0xacac872b, 0x9d9dfb66, 0x6a6af298, 0xd9d9ae77, 0xa8a8822a, 0xfafa46bc, 0x10101404, 0x0f0fcfc0, 0xaaaa02a8, 0x11115445, 0x4c4c5f13, 0x9898be26, 0x25256d48, 0x1a1a9e84, 0x18181e06, 0x6666fd9b,
+	0x7272ec9e, 0x09094a43, 0x41411051, 0xd3d324f7, 0x4646d593, 0xbfbf53ec, 0x6262f89a, 0xe9e9927b, 0xccccff33, 0x51510455, 0x2c2c270b, 0x0d0d4f42, 0xb7b759ee, 0x3f3ff3cc, 0xb2b21cae, 0x8989ea63,
+	0x939374e7, 0xcece7fb1, 0x70706c1c, 0xa6a60dab, 0x2727edca, 0x20202808, 0xa3a348eb, 0x5656c197, 0x02028082, 0x7f7fa3dc, 0x5252c496, 0xebeb12f9, 0xd5d5a174, 0x3e3eb38d, 0xfcfcc33f, 0x9a9a3ea4,
+	0x1d1d5b46, 0x1c1c1b07, 0x9e9e3ba5, 0xf3f30cff, 0xcfcf3ff0, 0xcdcdbf72, 0x5c5c4b17, 0xeaea52b8, 0x0e0e8f81, 0x65653d58, 0xf0f0cc3c, 0x64647d19, 0x9b9b7ee5, 0x16169187, 0x3d3d734e, 0xa2a208aa,
+	0xa1a1c869, 0xadadc76a, 0x06068583, 0xcaca7ab0, 0xc5c5b570, 0x9191f465, 0x6b6bb2d9, 0x2e2ea789, 0xe3e318fb, 0xafaf47e8, 0x3c3c330f, 0x2d2d674a, 0xc1c1b071, 0x59590e57, 0x7676e99f, 0xd4d4e135,
+	0x7878661e, 0x9090b424, 0x3838360e, 0x7979265f, 0x8d8def62, 0x61613859, 0x474795d2, 0x8a8a2aa0, 0x9494b125, 0x8888aa22, 0xf1f18c7d, 0xececd73b, 0x04040501, 0x8484a521, 0xe1e19879, 0x1e1e9b85,
+	0x535384d7, 0x00000000, 0x19195e47, 0x5d5d0b56, 0x7e7ee39d, 0x4f4f9fd0, 0x9c9cbb27, 0x49491a53, 0x31317c4d, 0xd8d8ee36, 0x08080a02, 0x9f9f7be4, 0x828220a2, 0x1313d4c7, 0x2323e8cb, 0x7a7ae69c,
+	0xabab42e9, 0xfefe43bd, 0x2a2aa288, 0x4b4b9ad1, 0x01014041, 0x1f1fdbc4, 0xe0e0d838, 0xd6d661b7, 0x8e8e2fa1, 0xdfdf2bf4, 0xcbcb3af1, 0x3b3bf6cd, 0xe7e71dfa, 0x8585e560, 0x54544115, 0x868625a3,
+	0x838360e3, 0xbaba16ac, 0x7575295c, 0x929234a6, 0x6e6ef799, 0xd0d0e434, 0x6868721a, 0x55550154, 0xb6b619af, 0x4e4edf91, 0xc8c8fa32, 0xc0c0f030, 0xd7d721f6, 0x3232bc8e, 0xc6c675b3, 0x8f8f6fe0,
+	0x7474691d, 0xdbdb2ef5, 0x8b8b6ae1, 0xb8b8962e, 0x0a0a8a80, 0x9999fe67, 0x2b2be2c9, 0x8181e061, 0x0303c0c3, 0xa4a48d29, 0x8c8caf23, 0xaeae07a9, 0x3434390d, 0x4d4d1f52, 0x3939764f, 0xbdbdd36e,
+	0x575781d6, 0x6f6fb7d8, 0xdcdceb37, 0x15155144, 0x7b7ba6dd, 0xf7f709fe, 0x3a3ab68c, 0xbcbc932f, 0x0c0c0f03, 0xffff03fc, 0xa9a9c26b, 0xc9c9ba73, 0xb5b5d96c, 0xb1b1dc6d, 0x6d6d375a, 0x45451550,
+	0x3636b98f, 0x6c6c771b, 0xbebe13ad, 0x4a4ada90, 0xeeee57b9, 0x7777a9de, 0xf2f24cbe, 0xfdfd837e, 0x44445511, 0x6767bdda, 0x71712c5d, 0x05054540, 0x7c7c631f, 0x40405010, 0x6969325b, 0x6363b8db,
+	0x2828220a, 0x0707c5c2, 0xc4c4f531, 0x2222a88a, 0x969631a7, 0x3737f9ce, 0xeded977a, 0xf6f649bf, 0xb4b4992d, 0xd1d1a475, 0x434390d3, 0x48485a12, 0xe2e258ba, 0x979771e6, 0xd2d264b6, 0xc2c270b2,
+	0x2626ad8b, 0xa5a5cd68, 0x5e5ecb95, 0x2929624b, 0x30303c0c, 0x5a5ace94, 0xddddab76, 0xf9f9867f, 0x9595f164, 0xe6e65dbb, 0xc7c735f2, 0x24242d09, 0x1717d1c6, 0xb9b9d66f, 0x1b1bdec5, 0x12129486,
+	0x60607818, 0xc3c330f3, 0xf5f5897c, 0xb3b35cef, 0xe8e8d23a, 0x7373acdf, 0x3535794c, 0x8080a020, 0xe5e59d78, 0xbbbb56ed, 0x7d7d235e, 0xf8f8c63e, 0x5f5f8bd4, 0x2f2fe7c8, 0xe4e4dd39, 0x21216849,
+}
+
+var sbox2 = [256]uint32{
+	0x5b8ed55b, 0x42d09242, 0xa74deaa7, 0xfb06fdfb, 0x33fccf33, 0x8765e287, 0xf4c93df4, 0xde6bb5de, 0x584e1658, 0xda6eb4da, 0x50441450, 0x0bcac10b, 0xa08828a0, 0xef17f8ef, 0xb09c2cb0, 0x14110514,
+	0xac872bac, 0x9dfb669d, 0x6af2986a, 0xd9ae77d9, 0xa8822aa8, 0xfa46bcfa, 0x10140410, 0x0fcfc00f, 0xaa02a8aa, 0x11544511, 0x4c5f134c, 0x98be2698, 0x256d4825, 0x1a9e841a, 0x181e0618, 0x66fd9b66,
+	0x72ec9e72, 0x094a4309, 0x41105141, 0xd324f7d3, 0x46d59346, 0xbf53ecbf, 0x62f89a62, 0xe9927be9, 0xccff33cc, 0x51045551, 0x2c270b2c, 0x0d4f420d, 0xb759eeb7, 0x3ff3cc3f, 0xb21caeb2, 0x89ea6389,
+	0x9374e793, 0xce7fb1ce, 0x706c1c70, 0xa60daba6, 0x27edca27, 0x20280820, 0xa348eba3, 0x56c19756, 0x02808202, 0x7fa3dc7f, 0x52c49652, 0xeb12f9eb, 0xd5a174d5, 0x3eb38d3e, 0xfcc33ffc, 0x9a3ea49a,
+	0x1d5b461d, 0x1c1b071c, 0x9e3ba59e, 0xf30cfff3, 0xcf3ff0cf, 0xcdbf72cd, 0x5c4b175c, 0xea52b8ea, 0x0e8f810e, 0x653d5865, 0xf0cc3cf0, 0x647d1964, 0x9b7ee59b, 0x16918716, 0x3d734e3d, 0xa208aaa2,
+	0xa1c869a1, 0xadc76aad, 0x06858306, 0xca7ab0ca, 0xc5b570c5, 0x91f46591, 0x6bb2d96b, 0x2ea7892e, 0xe318fbe3, 0xaf47e8af, 0x3c330f3c, 0x2d674a2d, 0xc1b071c1, 0x590e5759, 0x76e99f76, 0xd4e135d4,
+	0x78661e78, 0x90b42490, 0x38360e38, 0x79265f79, 0x8def628d, 0x61385961, 0x4795d247, 0x8a2aa08a, 0x94b12594, 0x88aa2288, 0xf18c7df1, 0xecd73bec, 0x04050104, 0x84a52184, 0xe19879e1, 0x1e9b851e,
+	0x5384d753, 0x00000000, 0x195e4719, 0x5d0b565d, 0x7ee39d7e, 0x4f9fd04f, 0x9cbb279c, 0x491a5349, 0x317c4d31, 0xd8ee36d8, 0x080a0208, 0x9f7be49f, 0x8220a282, 0x13d4c713, 0x23e8cb23, 0x7ae69c7a,
+	0xab42e9ab, 0xfe43bdfe, 0x2aa2882a, 0x4b9ad14b, 0x01404101, 0x1fdbc41f, 0xe0d838e0, 0xd661b7d6, 0x8e2fa18e, 0xdf2bf4df, 0xcb3af1cb, 0x3bf6cd3b, 0xe71dfae7, 0x85e56085, 0x54411554, 0x8625a386,
+	0x8360e383, 0xba16acba, 0x75295c75, 0x9234a692, 0x6ef7996e, 0xd0e434d0, 0x68721a68, 0x55015455, 0xb619afb6, 0x4edf914e, 0xc8fa32c8, 0xc0f030c0, 0xd721f6d7, 0x32bc8e32, 0xc675b3c6, 0x8f6fe08f,
+	0x74691d74, 0xdb2ef5db, 0x8b6ae18b, 0xb8962eb8, 0x0a8a800a, 0x99fe6799, 0x2be2c92b, 0x81e06181, 0x03c0c303, 0xa48d29a4, 0x8caf238c, 0xae07a9ae, 0x34390d34, 0x4d1f524d, 0x39764f39, 0xbdd36ebd,
+	0x5781d657, 0x6fb7d86f, 0xdceb37dc, 0x15514415, 0x7ba6dd7b, 0xf709fef7, 0x3ab68c3a, 0xbc932fbc, 0x0c0f030c, 0xff03fcff, 0xa9c26ba9, 0xc9ba73c9, 0xb5d96cb5, 0xb1dc6db1, 0x6d375a6d, 0x45155045,
+	0x36b98f36, 0x6c771b6c, 0xbe13adbe, 0x4ada904a, 0xee57b9ee, 0x77a9de77, 0xf24cbef2, 0xfd837efd, 0x44551144, 0x67bdda67, 0x712c5d71, 0x05454005, 0x7c631f7c, 0x40501040, 0x69325b69, 0x63b8db63,
+	0x28220a28, 0x07c5c207, 0xc4f531c4, 0x22a88a22, 0x9631a796, 0x37f9ce37, 0xed977aed, 0xf649bff6, 0xb4992db4, 0xd1a475d1, 0x4390d343, 0x485a1248, 0xe258bae2, 0x9771e697, 0xd264b6d2, 0xc270b2c2,
+	0x26ad8b26, 0xa5cd68a5, 0x5ecb955e, 0x29624b29, 0x303c0c30, 0x5ace945a, 0xddab76dd, 0xf9867ff9, 0x95f16495, 0xe65dbbe6, 0xc735f2c7, 0x242d0924, 0x17d1c617, 0xb9d66fb9, 0x1bdec51b, 0x12948612,
+	0x60781860, 0xc330f3c3, 0xf5897cf5, 0xb35cefb3, 0xe8d23ae8, 0x73acdf73, 0x35794c35, 0x80a02080, 0xe59d78e5, 0xbb56edbb, 0x7d235e7d, 0xf8c63ef8, 0x5f8bd45f, 0x2fe7c82f, 0xe4dd39e4, 0x21684921,
+}
+
+var sbox3 = [256]uint32{
+	0x8ed55b5b, 0xd0924242, 0x4deaa7a7, 0x06fdfbfb, 0xfccf3333, 0x65e28787, 0xc93df4f4, 0x6bb5dede, 0x4e165858, 0x6eb4dada, 0x44145050, 0xcac10b0b, 0x8828a0a0, 0x17f8efef, 0x9c2cb0b0, 0x11051414,
+	0x872bacac, 0xfb669d9d, 0xf2986a6a, 0xae77d9d9, 0x822aa8a8, 0x46bcfafa, 0x14041010, 0xcfc00f0f, 0x02a8aaaa, 0x54451111, 0x5f134c4c, 0xbe269898, 0x6d482525, 0x9e841a1a, 0x1e061818, 0xfd9b6666,
+	0xec9e7272, 0x4a430909, 0x10514141, 0x24f7d3d3, 0xd5934646, 0x53ecbfbf, 0xf89a6262, 0x927be9e9, 0xff33cccc, 0x04555151, 0x270b2c2c, 0x4f420d0d, 0x59eeb7b7, 0xf3cc3f3f, 0x1caeb2b2, 0xea638989,
+	0x74e79393, 0x7fb1cece, 0x6c1c7070, 0x0daba6a6, 0xedca2727, 0x28082020, 0x48eba3a3, 0xc1975656, 0x80820202, 0xa3dc7f7f, 0xc4965252, 0x12f9ebeb, 0xa174d5d5, 0xb38d3e3e, 0xc33ffcfc, 0x3ea49a9a,
+	0x5b461d1d, 0x1b071c1c, 0x3ba59e9e, 0x0cfff3f3, 0x3ff0cfcf, 0xbf72cdcd, 0x4b175c5c, 0x52b8eaea, 0x8f810e0e, 0x3d586565, 0xcc3cf0f0, 0x7d196464, 0x7ee59b9b, 0x91871616, 0x734e3d3d, 0x08aaa2a2,
+	0xc869a1a1, 0xc76aadad, 0x85830606, 0x7ab0caca, 0xb570c5c5, 0xf4659191, 0xb2d96b6b, 0xa7892e2e, 0x18fbe3e3, 0x47e8afaf, 0x330f3c3c, 0x674a2d2d, 0xb071c1c1, 0x0e575959, 0xe99f7676, 0xe135d4d4,
+	0x661e7878, 0xb4249090, 0x360e3838, 0x265f7979, 0xef628d8d, 0x38596161, 0x95d24747, 0x2aa08a8a, 0xb1259494, 0xaa228888, 0x8c7df1f1, 0xd73becec, 0x05010404, 0xa5218484, 0x9879e1e1, 0x9b851e1e,
+	0x84d75353, 0x00000000, 0x5e471919, 0x0b565d5d, 0xe39d7e7e, 0x9fd04f4f, 0xbb279c9c, 0x1a534949, 0x7c4d3131, 0xee36d8d8, 0x0a020808, 0x7be49f9f, 0x20a28282, 0xd4c71313, 0xe8cb2323, 0xe69c7a7a,
+	0x42e9abab, 0x43bdfefe, 0xa2882a2a, 0x9ad14b4b, 0x40410101, 0xdbc41f1f, 0xd838e0e0, 0x61b7d6d6, 0x2fa18e8e, 0x2bf4dfdf, 0x3af1cbcb, 0xf6cd3b3b, 0x1dfae7e7, 0xe5608585, 0x41155454, 0x25a38686,
+	0x60e38383, 0x16acbaba, 0x295c7575, 0x34a69292, 0xf7996e6e, 0xe434d0d0, 0x721a6868, 0x01545555, 0x19afb6b6, 0xdf914e4e, 0xfa32c8c8, 0xf030c0c0, 0x21f6d7d7, 0xbc8e3232, 0x75b3c6c6, 0x6fe08f8f,
+	0x691d7474, 0x2ef5dbdb, 0x6ae18b8b, 0x962eb8b8, 0x8a800a0a, 0xfe679999, 0xe2c92b2b, 0xe0618181, 0xc0c30303, 0x8d29a4a4, 0xaf238c8c, 0x07a9aeae, 0x390d3434, 0x1f524d4d, 0x764f3939, 0xd36ebdbd,
+	0x81d65757, 0xb7d86f6f, 0xeb37dcdc, 0x51441515, 0xa6dd7b7b, 0x09fef7f7, 0xb68c3a3a, 0x932fbcbc, 0x0f030c0c, 0x03fcffff, 0xc26ba9a9, 0xba73c9c9, 0xd96cb5b5, 0xdc6db1b1, 0x375a6d6d, 0x15504545,
+	0xb98f3636, 0x771b6c6c, 0x13adbebe, 0xda904a4a, 0x57b9eeee, 0xa9de7777, 0x4cbef2f2, 0x837efdfd, 0x55114444, 0xbdda6767, 0x2c5d7171, 0x45400505, 0x631f7c7c, 0x50104040, 0x325b6969, 0xb8db6363,
+	0x220a2828, 0xc5c20707, 0xf531c4c4, 0xa88a2222, 0x31a79696, 0xf9ce3737, 0x977aeded, 0x49bff6f6, 0x992db4b4, 0xa475d1d1, 0x90d34343, 0x5a124848, 0x58bae2e2, 0x71e69797, 0x64b6d2d2, 0x70b2c2c2,
+	0xad8b2626, 0xcd68a5a5, 0xcb955e5e, 0x624b2929, 0x3c0c3030, 0xce945a5a, 0xab76dddd, 0x867ff9f9, 0xf1649595, 0x5dbbe6e6, 0x35f2c7c7, 0x2d092424, 0xd1c61717, 0xd66fb9b9, 0xdec51b1b, 0x94861212,
+	0x78186060, 0x30f3c3c3, 0x897cf5f5, 0x5cefb3b3, 0xd23ae8e8, 0xacdf7373, 0x794c3535, 0xa0208080, 0x9d78e5e5, 0x56edbbbb, 0x235e7d7d, 0xc63ef8f8, 0x8bd45f5f, 0xe7c82f2f, 0xdd39e4e4, 0x68492121,
+}
+
+func rl(x uint32, i uint8) uint32 { return (x << (i % 32)) | (x >> (32 - (i % 32))) }
+
+func l0(b uint32) uint32 { return b ^ rl(b, 13) ^ rl(b, 23) }
+
+func feistel0(x0, x1, x2, x3, rk uint32) uint32 { return x0 ^ l0(p(x1^x2^x3^rk)) }
+
+//非线性变换τ(.)
+func p(a uint32) uint32 {
+	return (uint32(sbox[a>>24]) << 24) ^ (uint32(sbox[(a>>16)&0xff]) << 16) ^ (uint32(sbox[(a>>8)&0xff]) << 8) ^ uint32(sbox[(a)&0xff])
+}
+
+func permuteInitialBlock(b []uint32, block []byte) {
+	for i := 0; i < 4; i++ {
+		b[i] = (uint32(block[i*4]) << 24) | (uint32(block[i*4+1]) << 16) |
+			(uint32(block[i*4+2]) << 8) | (uint32(block[i*4+3]))
+	}
+}
+
+func permuteFinalBlock(b []byte, block []uint32) {
+	for i := 0; i < 4; i++ {
+		b[i*4] = uint8(block[i] >> 24)
+		b[i*4+1] = uint8(block[i] >> 16)
+		b[i*4+2] = uint8(block[i] >> 8)
+		b[i*4+3] = uint8(block[i])
+	}
+}
+
+//修改后的加密核心函数
+func cryptBlock(subkeys []uint32, b []uint32, r []byte, dst, src []byte, decrypt bool) {
+	var x uint32
+	permuteInitialBlock(b, src)
+	if decrypt {
+		for i := 0; i < 8; i++ {
+			x = b[1] ^ b[2] ^ b[3] ^ subkeys[31-4*i]
+			b[0] = b[0] ^ sbox0[x&0xff] ^ sbox1[(x>>8)&0xff] ^ sbox2[(x>>16)&0xff] ^ sbox3[(x>>24)&0xff]
+			x = b[0] ^ b[2] ^ b[3] ^ subkeys[31-4*i-1]
+			b[1] = b[1] ^ sbox0[x&0xff] ^ sbox1[(x>>8)&0xff] ^ sbox2[(x>>16)&0xff] ^ sbox3[(x>>24)&0xff]
+			x = b[0] ^ b[1] ^ b[3] ^ subkeys[31-4*i-2]
+			b[2] = b[2] ^ sbox0[x&0xff] ^ sbox1[(x>>8)&0xff] ^ sbox2[(x>>16)&0xff] ^ sbox3[(x>>24)&0xff]
+			x = b[1] ^ b[2] ^ b[0] ^ subkeys[31-4*i-3]
+			b[3] = b[3] ^ sbox0[x&0xff] ^ sbox1[(x>>8)&0xff] ^ sbox2[(x>>16)&0xff] ^ sbox3[(x>>24)&0xff]
+		}
+	} else {
+		for i := 0; i < 8; i++ {
+			x = b[1] ^ b[2] ^ b[3] ^ subkeys[4*i]
+			b[0] = b[0] ^ sbox0[x&0xff] ^ sbox1[(x>>8)&0xff] ^ sbox2[(x>>16)&0xff] ^ sbox3[(x>>24)&0xff]
+			x = b[0] ^ b[2] ^ b[3] ^ subkeys[4*i+1]
+			b[1] = b[1] ^ sbox0[x&0xff] ^ sbox1[(x>>8)&0xff] ^ sbox2[(x>>16)&0xff] ^ sbox3[(x>>24)&0xff]
+			x = b[0] ^ b[1] ^ b[3] ^ subkeys[4*i+2]
+			b[2] = b[2] ^ sbox0[x&0xff] ^ sbox1[(x>>8)&0xff] ^ sbox2[(x>>16)&0xff] ^ sbox3[(x>>24)&0xff]
+			x = b[1] ^ b[2] ^ b[0] ^ subkeys[4*i+3]
+			b[3] = b[3] ^ sbox0[x&0xff] ^ sbox1[(x>>8)&0xff] ^ sbox2[(x>>16)&0xff] ^ sbox3[(x>>24)&0xff]
+		}
+	}
+	b[0], b[1], b[2], b[3] = b[3], b[2], b[1], b[0]
+	permuteFinalBlock(r, b)
+	copy(dst, r)
+}
+
+func generateSubKeys(key []byte) []uint32 {
+	subkeys := make([]uint32, 32)
+	b := make([]uint32, 4)
+	permuteInitialBlock(b, key)
+	b[0] ^= fk[0]
+	b[1] ^= fk[1]
+	b[2] ^= fk[2]
+	b[3] ^= fk[3]
+	for i := 0; i < 32; i++ {
+		subkeys[i] = feistel0(b[0], b[1], b[2], b[3], ck[i])
+		b[0], b[1], b[2], b[3] = b[1], b[2], b[3], subkeys[i]
+	}
+	return subkeys
+}
+
+func EncryptBlock(key SM4Key, dst, src []byte) {
+	subkeys := generateSubKeys(key)
+	cryptBlock(subkeys, make([]uint32, 4), make([]byte, 16), dst, src, false)
+}
+
+func DecryptBlock(key SM4Key, dst, src []byte) {
+	subkeys := generateSubKeys(key)
+	cryptBlock(subkeys, make([]uint32, 4), make([]byte, 16), dst, src, true)
+}
+
+func ReadKeyFromMem(data []byte, pwd []byte) (SM4Key, error) {
+	block, _ := pem.Decode(data)
+	if x509.IsEncryptedPEMBlock(block) {
+		if block.Type != "SM4 ENCRYPTED KEY" {
+			return nil, errors.New("SM4: unknown type")
+		}
+		if pwd == nil {
+			return nil, errors.New("SM4: need passwd")
+		}
+		data, err := x509.DecryptPEMBlock(block, pwd)
+		if err != nil {
+			return nil, err
+		}
+		return data, nil
+	}
+	if block.Type != "SM4 KEY" {
+		return nil, errors.New("SM4: unknown type")
+	}
+	return block.Bytes, nil
+}
+
+func ReadKeyFromPem(FileName string, pwd []byte) (SM4Key, error) {
+	data, err := ioutil.ReadFile(FileName)
+	if err != nil {
+		return nil, err
+	}
+	return ReadKeyFromMem(data, pwd)
+}
+
+func WriteKeytoMem(key SM4Key, pwd []byte) ([]byte, error) {
+	if pwd != nil {
+		block, err := x509.EncryptPEMBlock(rand.Reader,
+			"SM4 ENCRYPTED KEY", key, pwd, x509.PEMCipherAES256)
+		if err != nil {
+			return nil, err
+		}
+		return pem.EncodeToMemory(block), nil
+	} else {
+		block := &pem.Block{
+			Type:  "SM4 KEY",
+			Bytes: key,
+		}
+		return pem.EncodeToMemory(block), nil
+	}
+}
+
+func WriteKeyToPem(FileName string, key SM4Key, pwd []byte) (bool, error) {
+	var block *pem.Block
+
+	if pwd != nil {
+		var err error
+		block, err = x509.EncryptPEMBlock(rand.Reader,
+			"SM4 ENCRYPTED KEY", key, pwd, x509.PEMCipherAES256)
+		if err != nil {
+			return false, err
+		}
+	} else {
+		block = &pem.Block{
+			Type:  "SM4 KEY",
+			Bytes: key,
+		}
+	}
+	file, err := os.Create(FileName)
+	if err != nil {
+		return false, err
+	}
+	defer file.Close()
+	err = pem.Encode(file, block)
+	if err != nil {
+		return false, nil
+	}
+	return true, nil
+}
+
+func (k KeySizeError) Error() string {
+	return "SM4: invalid key size " + strconv.Itoa(int(k))
+}
+
+// NewCipher creates and returns a new cipher.Block.
+func NewCipher(key []byte) (cipher.Block, error) {
+	if len(key) != BlockSize {
+		return nil, KeySizeError(len(key))
+	}
+	c := new(Sm4Cipher)
+	c.subkeys = generateSubKeys(key)
+	c.block1 = make([]uint32, 4)
+	c.block2 = make([]byte, 16)
+	return c, nil
+}
+
+func (c *Sm4Cipher) BlockSize() int {
+	return BlockSize
+}
+
+func (c *Sm4Cipher) Encrypt(dst, src []byte) {
+	cryptBlock(c.subkeys, c.block1, c.block2, dst, src, false)
+}
+
+func (c *Sm4Cipher) Decrypt(dst, src []byte) {
+	cryptBlock(c.subkeys, c.block1, c.block2, dst, src, true)
+}

vendor/github.com/xtaci/kcp-go/LICENSE

@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 Daniel Fu
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+

vendor/github.com/xtaci/kcp-go/README.md

@@ -0,0 +1,172 @@
+<img src="kcp-go.png" alt="kcp-go" height="50px" />
+
+
+[![GoDoc][1]][2] [![Powered][9]][10] [![MIT licensed][11]][12] [![Build Status][3]][4] [![Go Report Card][5]][6] [![Coverage Statusd][7]][8]
+
+[1]: https://godoc.org/github.com/xtaci/kcp-go?status.svg
+[2]: https://godoc.org/github.com/xtaci/kcp-go
+[3]: https://travis-ci.org/xtaci/kcp-go.svg?branch=master
+[4]: https://travis-ci.org/xtaci/kcp-go
+[5]: https://goreportcard.com/badge/github.com/xtaci/kcp-go
+[6]: https://goreportcard.com/report/github.com/xtaci/kcp-go
+[7]: https://codecov.io/gh/xtaci/kcp-go/branch/master/graph/badge.svg
+[8]: https://codecov.io/gh/xtaci/kcp-go
+[9]: https://img.shields.io/badge/KCP-Powered-blue.svg
+[10]: https://github.com/skywind3000/kcp
+[11]: https://img.shields.io/badge/license-MIT-blue.svg
+[12]: LICENSE
+
+## Introduction
+
+**kcp-go** is a **Production-Grade Reliable-UDP** library for [golang](https://golang.org/). 
+
+It provides **fast, ordered and error-checked** delivery of streams over **UDP** packets, has been well tested with opensource project [kcptun](https://github.com/xtaci/kcptun). Millions of devices(from low-end MIPS routers to high-end servers) are running with **kcp-go** at present, including applications like **online games, live broadcasting, file synchronization and network acceleration**.
+
+[Lastest Release](https://github.com/xtaci/kcp-go/releases)
+
+## Features
+
+1. Optimized for **Realtime Online Games, Audio/Video Streaming and Latency-Sensitive Distributed Consensus**.
+1. Compatible with [skywind3000's](https://github.com/skywind3000) C version with language specific optimizations.
+1. **Cache friendly** and **Memory optimized** design, offers extremely **High Performance** core.
+1. Handles **>5K concurrent connections** on a single commodity server.
+1. Compatible with [net.Conn](https://golang.org/pkg/net/#Conn) and [net.Listener](https://golang.org/pkg/net/#Listener), a drop-in replacement for [net.TCPConn](https://golang.org/pkg/net/#TCPConn).
+1. [FEC(Forward Error Correction)](https://en.wikipedia.org/wiki/Forward_error_correction) Support with [Reed-Solomon Codes](https://en.wikipedia.org/wiki/Reed%E2%80%93Solomon_error_correction)
+1. Packet level encryption support with [AES](https://en.wikipedia.org/wiki/Advanced_Encryption_Standard), [TEA](https://en.wikipedia.org/wiki/Tiny_Encryption_Algorithm), [3DES](https://en.wikipedia.org/wiki/Triple_DES), [Blowfish](https://en.wikipedia.org/wiki/Blowfish_(cipher)), [Cast5](https://en.wikipedia.org/wiki/CAST-128), [Salsa20]( https://en.wikipedia.org/wiki/Salsa20), etc. in [CFB](https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Cipher_Feedback_.28CFB.29) mode.
+1. **Fixed number of goroutines** created for the entire server application, minimized goroutine context switch.
+
+## Conventions
+
+Control messages like **SYN/FIN/RST** in TCP **are not defined** in KCP, you need some **keepalive/heartbeat mechanism** in the application-level. A real world example is to use some **multiplexing** protocol over session, such as [smux](https://github.com/xtaci/smux)(with embedded keepalive mechanism), see [kcptun](https://github.com/xtaci/kcptun) for example.
+
+## Documentation
+
+For complete documentation, see the associated [Godoc](https://godoc.org/github.com/xtaci/kcp-go).
+
+## Specification
+
+<img src="frame.png" alt="Frame Format" height="109px" />
+
+```
++-----------------+
+| SESSION         |
++-----------------+
+| KCP(ARQ)        |
++-----------------+
+| FEC(OPTIONAL)   |
++-----------------+
+| CRYPTO(OPTIONAL)|
++-----------------+
+| UDP(PACKET)     |
++-----------------+
+| IP              |
++-----------------+
+| LINK            |
++-----------------+
+| PHY             |
++-----------------+
+(LAYER MODEL OF KCP-GO)
+```
+
+
+## Usage
+
+Client:   [full demo](https://github.com/xtaci/kcptun/blob/master/client/main.go)
+```go
+kcpconn, err := kcp.DialWithOptions("192.168.0.1:10000", nil, 10, 3)
+```
+Server:   [full demo](https://github.com/xtaci/kcptun/blob/master/server/main.go)
+```go
+lis, err := kcp.ListenWithOptions(":10000", nil, 10, 3)
+```
+
+## Performance
+```
+  Model Name:	MacBook Pro
+  Model Identifier:	MacBookPro12,1
+  Processor Name:	Intel Core i5
+  Processor Speed:	2.7 GHz
+  Number of Processors:	1
+  Total Number of Cores:	2
+  L2 Cache (per Core):	256 KB
+  L3 Cache:	3 MB
+  Memory:	8 GB
+```
+```
+$ go test -v -run=^$ -bench .
+beginning tests, encryption:salsa20, fec:10/3
+BenchmarkAES128-4          	  200000	      8256 ns/op	 363.33 MB/s	       0 B/op	       0 allocs/op
+BenchmarkAES192-4          	  200000	      9153 ns/op	 327.74 MB/s	       0 B/op	       0 allocs/op
+BenchmarkAES256-4          	  200000	     10079 ns/op	 297.64 MB/s	       0 B/op	       0 allocs/op
+BenchmarkTEA-4             	  100000	     18643 ns/op	 160.91 MB/s	       0 B/op	       0 allocs/op
+BenchmarkXOR-4             	 5000000	       316 ns/op	9486.46 MB/s	       0 B/op	       0 allocs/op
+BenchmarkBlowfish-4        	   50000	     35643 ns/op	  84.17 MB/s	       0 B/op	       0 allocs/op
+BenchmarkNone-4            	30000000	        56.2 ns/op	53371.83 MB/s	       0 B/op	       0 allocs/op
+BenchmarkCast5-4           	   30000	     44744 ns/op	  67.05 MB/s	       0 B/op	       0 allocs/op
+Benchmark3DES-4            	    2000	    639839 ns/op	   4.69 MB/s	       2 B/op	       0 allocs/op
+BenchmarkTwofish-4         	   30000	     43368 ns/op	  69.17 MB/s	       0 B/op	       0 allocs/op
+BenchmarkXTEA-4            	   30000	     57673 ns/op	  52.02 MB/s	       0 B/op	       0 allocs/op
+BenchmarkSalsa20-4         	  300000	      3917 ns/op	 765.80 MB/s	       0 B/op	       0 allocs/op
+BenchmarkFlush-4           	10000000	       226 ns/op	       0 B/op	       0 allocs/op
+BenchmarkEchoSpeed4K-4     	    5000	    300030 ns/op	  13.65 MB/s	    5672 B/op	     177 allocs/op
+BenchmarkEchoSpeed64K-4    	     500	   3202335 ns/op	  20.47 MB/s	   73295 B/op	    2198 allocs/op
+BenchmarkEchoSpeed512K-4   	      50	  24926924 ns/op	  21.03 MB/s	  659339 B/op	   17602 allocs/op
+BenchmarkEchoSpeed1M-4     	      20	  64857821 ns/op	  16.17 MB/s	 1772437 B/op	   42869 allocs/op
+BenchmarkSinkSpeed4K-4     	   30000	     50230 ns/op	  81.54 MB/s	    2058 B/op	      48 allocs/op
+BenchmarkSinkSpeed64K-4    	    2000	    648718 ns/op	 101.02 MB/s	   31165 B/op	     687 allocs/op
+BenchmarkSinkSpeed256K-4   	     300	   4635905 ns/op	 113.09 MB/s	  286229 B/op	    5516 allocs/op
+BenchmarkSinkSpeed1M-4     	     200	   9566933 ns/op	 109.60 MB/s	  463771 B/op	   10701 allocs/op
+PASS
+ok  	_/Users/xtaci/.godeps/src/github.com/xtaci/kcp-go	39.689s
+```
+
+## Design Considerations
+
+1. slice vs. container/list
+
+`kcp.flush()` loops through the send queue for retransmission checking for every 20ms(interval).
+
+I've wrote a benchmark for comparing sequential loop through *slice* and *container/list* here:
+
+https://github.com/xtaci/notes/blob/master/golang/benchmark2/cachemiss_test.go
+
+```
+BenchmarkLoopSlice-4   	2000000000	         0.39 ns/op
+BenchmarkLoopList-4    	100000000	        54.6 ns/op
+```
+
+List structure introduces **heavy cache misses** compared to slice which owns better **locality**, 5000 connections with 32 window size and 20ms interval will cost 6us/0.03%(cpu) using slice, and 8.7ms/43.5%(cpu) for list for each `kcp.flush()`.
+
+2. Timing accuracy vs. syscall clock_gettime
+
+Timing is **critical** to **RTT estimator**, inaccurate timing introduces false retransmissions in KCP, but calling `time.Now()` costs 42 cycles(10.5ns on 4GHz CPU, 15.6ns on my MacBook Pro 2.7GHz), the benchmark for time.Now():
+
+https://github.com/xtaci/notes/blob/master/golang/benchmark2/syscall_test.go
+
+```
+BenchmarkNow-4         	100000000	        15.6 ns/op
+```
+
+In kcp-go, after each `kcp.output()` function call, current time will be updated upon return, and each `kcp.flush()` will get current time once. For most of the time, 5000 connections costs 5000 * 15.6ns = 78us(no packet needs to be sent by `kcp.output()`), as for 10MB/s data transfering with 1400 MTU, `kcp.output()` will be called around 7500 times and costs 117us for `time.Now()` in **every second**.
+
+
+## Tuning
+
+Q: I'm handling >5K connections on my server. the CPU utilization is high.
+
+A: A standalone `agent` or `gate` server for kcp-go is suggested, not only for CPU utilization, but also important to the **precision** of RTT measurements which indirectly affects retransmission. By increasing update `interval` with `SetNoDelay` like `conn.SetNoDelay(1, 40, 1, 1)` will dramatically reduce system load.
+
+## Who is using this?
+
+1. https://github.com/xtaci/kcptun -- A Secure Tunnel Based On KCP over UDP.
+2. https://github.com/getlantern/lantern -- Lantern delivers fast access to the open Internet. 
+3. https://github.com/smallnest/rpcx -- A RPC service framework based on net/rpc like alibaba Dubbo and weibo Motan.
+4. https://github.com/gonet2/agent -- A gateway for games with stream multiplexing.
+5. https://github.com/syncthing/syncthing -- Open Source Continuous File Synchronization.
+6. https://play.google.com/store/apps/details?id=com.k17game.k3 -- Battle Zone - Earth 2048, a world-wide strategy game.
+
+## Links
+
+1. https://github.com/xtaci/libkcp -- FEC enhanced KCP session library for iOS/Android in C++
+2. https://github.com/skywind3000/kcp -- A Fast and Reliable ARQ Protocol
+3. https://github.com/templexxx/reedsolomon -- Reed-Solomon Erasure Coding in Go

vendor/github.com/xtaci/kcp-go/crypt.go

@@ -0,0 +1,288 @@
+package kcp
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/des"
+	"crypto/sha1"
+
+	"github.com/templexxx/xor"
+	"github.com/tjfoc/gmsm/sm4"
+
+	"golang.org/x/crypto/blowfish"
+	"golang.org/x/crypto/cast5"
+	"golang.org/x/crypto/pbkdf2"
+	"golang.org/x/crypto/salsa20"
+	"golang.org/x/crypto/tea"
+	"golang.org/x/crypto/twofish"
+	"golang.org/x/crypto/xtea"
+)
+
+var (
+	initialVector = []byte{167, 115, 79, 156, 18, 172, 27, 1, 164, 21, 242, 193, 252, 120, 230, 107}
+	saltxor       = `sH3CIVoF#rWLtJo6`
+)
+
+// BlockCrypt defines encryption/decryption methods for a given byte slice.
+// Notes on implementing: the data to be encrypted contains a builtin
+// nonce at the first 16 bytes
+type BlockCrypt interface {
+	// Encrypt encrypts the whole block in src into dst.
+	// Dst and src may point at the same memory.
+	Encrypt(dst, src []byte)
+
+	// Decrypt decrypts the whole block in src into dst.
+	// Dst and src may point at the same memory.
+	Decrypt(dst, src []byte)
+}
+
+type salsa20BlockCrypt struct {
+	key [32]byte
+}
+
+// NewSalsa20BlockCrypt https://en.wikipedia.org/wiki/Salsa20
+func NewSalsa20BlockCrypt(key []byte) (BlockCrypt, error) {
+	c := new(salsa20BlockCrypt)
+	copy(c.key[:], key)
+	return c, nil
+}
+
+func (c *salsa20BlockCrypt) Encrypt(dst, src []byte) {
+	salsa20.XORKeyStream(dst[8:], src[8:], src[:8], &c.key)
+	copy(dst[:8], src[:8])
+}
+func (c *salsa20BlockCrypt) Decrypt(dst, src []byte) {
+	salsa20.XORKeyStream(dst[8:], src[8:], src[:8], &c.key)
+	copy(dst[:8], src[:8])
+}
+
+type sm4BlockCrypt struct {
+	encbuf []byte
+	decbuf []byte
+	block  cipher.Block
+}
+
+// NewSM4BlockCrypt https://github.com/tjfoc/gmsm/tree/master/sm4
+func NewSM4BlockCrypt(key []byte) (BlockCrypt, error) {
+	c := new(sm4BlockCrypt)
+	block, err := sm4.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	c.block = block
+	c.encbuf = make([]byte, sm4.BlockSize)
+	c.decbuf = make([]byte, 2*sm4.BlockSize)
+	return c, nil
+}
+
+func (c *sm4BlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
+func (c *sm4BlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }
+
+type twofishBlockCrypt struct {
+	encbuf []byte
+	decbuf []byte
+	block  cipher.Block
+}
+
+// NewTwofishBlockCrypt https://en.wikipedia.org/wiki/Twofish
+func NewTwofishBlockCrypt(key []byte) (BlockCrypt, error) {
+	c := new(twofishBlockCrypt)
+	block, err := twofish.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	c.block = block
+	c.encbuf = make([]byte, twofish.BlockSize)
+	c.decbuf = make([]byte, 2*twofish.BlockSize)
+	return c, nil
+}
+
+func (c *twofishBlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
+func (c *twofishBlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }
+
+type tripleDESBlockCrypt struct {
+	encbuf []byte
+	decbuf []byte
+	block  cipher.Block
+}
+
+// NewTripleDESBlockCrypt https://en.wikipedia.org/wiki/Triple_DES
+func NewTripleDESBlockCrypt(key []byte) (BlockCrypt, error) {
+	c := new(tripleDESBlockCrypt)
+	block, err := des.NewTripleDESCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	c.block = block
+	c.encbuf = make([]byte, des.BlockSize)
+	c.decbuf = make([]byte, 2*des.BlockSize)
+	return c, nil
+}
+
+func (c *tripleDESBlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
+func (c *tripleDESBlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }
+
+type cast5BlockCrypt struct {
+	encbuf []byte
+	decbuf []byte
+	block  cipher.Block
+}
+
+// NewCast5BlockCrypt https://en.wikipedia.org/wiki/CAST-128
+func NewCast5BlockCrypt(key []byte) (BlockCrypt, error) {
+	c := new(cast5BlockCrypt)
+	block, err := cast5.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	c.block = block
+	c.encbuf = make([]byte, cast5.BlockSize)
+	c.decbuf = make([]byte, 2*cast5.BlockSize)
+	return c, nil
+}
+
+func (c *cast5BlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
+func (c *cast5BlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }
+
+type blowfishBlockCrypt struct {
+	encbuf []byte
+	decbuf []byte
+	block  cipher.Block
+}
+
+// NewBlowfishBlockCrypt https://en.wikipedia.org/wiki/Blowfish_(cipher)
+func NewBlowfishBlockCrypt(key []byte) (BlockCrypt, error) {
+	c := new(blowfishBlockCrypt)
+	block, err := blowfish.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	c.block = block
+	c.encbuf = make([]byte, blowfish.BlockSize)
+	c.decbuf = make([]byte, 2*blowfish.BlockSize)
+	return c, nil
+}
+
+func (c *blowfishBlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
+func (c *blowfishBlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }
+
+type aesBlockCrypt struct {
+	encbuf []byte
+	decbuf []byte
+	block  cipher.Block
+}
+
+// NewAESBlockCrypt https://en.wikipedia.org/wiki/Advanced_Encryption_Standard
+func NewAESBlockCrypt(key []byte) (BlockCrypt, error) {
+	c := new(aesBlockCrypt)
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	c.block = block
+	c.encbuf = make([]byte, aes.BlockSize)
+	c.decbuf = make([]byte, 2*aes.BlockSize)
+	return c, nil
+}
+
+func (c *aesBlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
+func (c *aesBlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }
+
+type teaBlockCrypt struct {
+	encbuf []byte
+	decbuf []byte
+	block  cipher.Block
+}
+
+// NewTEABlockCrypt https://en.wikipedia.org/wiki/Tiny_Encryption_Algorithm
+func NewTEABlockCrypt(key []byte) (BlockCrypt, error) {
+	c := new(teaBlockCrypt)
+	block, err := tea.NewCipherWithRounds(key, 16)
+	if err != nil {
+		return nil, err
+	}
+	c.block = block
+	c.encbuf = make([]byte, tea.BlockSize)
+	c.decbuf = make([]byte, 2*tea.BlockSize)
+	return c, nil
+}
+
+func (c *teaBlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
+func (c *teaBlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }
+
+type xteaBlockCrypt struct {
+	encbuf []byte
+	decbuf []byte
+	block  cipher.Block
+}
+
+// NewXTEABlockCrypt https://en.wikipedia.org/wiki/XTEA
+func NewXTEABlockCrypt(key []byte) (BlockCrypt, error) {
+	c := new(xteaBlockCrypt)
+	block, err := xtea.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	c.block = block
+	c.encbuf = make([]byte, xtea.BlockSize)
+	c.decbuf = make([]byte, 2*xtea.BlockSize)
+	return c, nil
+}
+
+func (c *xteaBlockCrypt) Encrypt(dst, src []byte) { encrypt(c.block, dst, src, c.encbuf) }
+func (c *xteaBlockCrypt) Decrypt(dst, src []byte) { decrypt(c.block, dst, src, c.decbuf) }
+
+type simpleXORBlockCrypt struct {
+	xortbl []byte
+}
+
+// NewSimpleXORBlockCrypt simple xor with key expanding
+func NewSimpleXORBlockCrypt(key []byte) (BlockCrypt, error) {
+	c := new(simpleXORBlockCrypt)
+	c.xortbl = pbkdf2.Key(key, []byte(saltxor), 32, mtuLimit, sha1.New)
+	return c, nil
+}
+
+func (c *simpleXORBlockCrypt) Encrypt(dst, src []byte) { xor.Bytes(dst, src, c.xortbl) }
+func (c *simpleXORBlockCrypt) Decrypt(dst, src []byte) { xor.Bytes(dst, src, c.xortbl) }
+
+type noneBlockCrypt struct{}
+
+// NewNoneBlockCrypt does nothing but copying
+func NewNoneBlockCrypt(key []byte) (BlockCrypt, error) {
+	return new(noneBlockCrypt), nil
+}
+
+func (c *noneBlockCrypt) Encrypt(dst, src []byte) { copy(dst, src) }
+func (c *noneBlockCrypt) Decrypt(dst, src []byte) { copy(dst, src) }
+
+// packet encryption with local CFB mode
+func encrypt(block cipher.Block, dst, src, buf []byte) {
+	blocksize := block.BlockSize()
+	tbl := buf[:blocksize]
+	block.Encrypt(tbl, initialVector)
+	n := len(src) / blocksize
+	base := 0
+	for i := 0; i < n; i++ {
+		xor.BytesSrc1(dst[base:], src[base:], tbl)
+		block.Encrypt(tbl, dst[base:])
+		base += blocksize
+	}
+	xor.BytesSrc0(dst[base:], src[base:], tbl)
+}
+
+func decrypt(block cipher.Block, dst, src, buf []byte) {
+	blocksize := block.BlockSize()
+	tbl := buf[:blocksize]
+	next := buf[blocksize:]
+	block.Encrypt(tbl, initialVector)
+	n := len(src) / blocksize
+	base := 0
+	for i := 0; i < n; i++ {
+		block.Encrypt(next, src[base:])
+		xor.BytesSrc1(dst[base:], src[base:], tbl)
+		tbl, next = next, tbl
+		base += blocksize
+	}
+	xor.BytesSrc0(dst[base:], src[base:], tbl)
+}

vendor/github.com/xtaci/kcp-go/fec.go

@@ -0,0 +1,303 @@
+package kcp
+
+import (
+	"encoding/binary"
+	"sync/atomic"
+
+	"github.com/templexxx/reedsolomon"
+)
+
+const (
+	fecHeaderSize      = 6
+	fecHeaderSizePlus2 = fecHeaderSize + 2 // plus 2B data size
+	typeData           = 0xf1
+	typeFEC            = 0xf2
+)
+
+type (
+	// fecPacket is a decoded FEC packet
+	fecPacket struct {
+		seqid uint32
+		flag  uint16
+		data  []byte
+	}
+
+	// fecDecoder for decoding incoming packets
+	fecDecoder struct {
+		rxlimit      int // queue size limit
+		dataShards   int
+		parityShards int
+		shardSize    int
+		rx           []fecPacket // ordered receive queue
+
+		// caches
+		decodeCache [][]byte
+		flagCache   []bool
+
+		// RS decoder
+		codec reedsolomon.Encoder
+	}
+)
+
+func newFECDecoder(rxlimit, dataShards, parityShards int) *fecDecoder {
+	if dataShards <= 0 || parityShards <= 0 {
+		return nil
+	}
+	if rxlimit < dataShards+parityShards {
+		return nil
+	}
+
+	fec := new(fecDecoder)
+	fec.rxlimit = rxlimit
+	fec.dataShards = dataShards
+	fec.parityShards = parityShards
+	fec.shardSize = dataShards + parityShards
+	enc, err := reedsolomon.New(dataShards, parityShards)
+	if err != nil {
+		return nil
+	}
+	fec.codec = enc
+	fec.decodeCache = make([][]byte, fec.shardSize)
+	fec.flagCache = make([]bool, fec.shardSize)
+	return fec
+}
+
+// decodeBytes a fec packet
+func (dec *fecDecoder) decodeBytes(data []byte) fecPacket {
+	var pkt fecPacket
+	pkt.seqid = binary.LittleEndian.Uint32(data)
+	pkt.flag = binary.LittleEndian.Uint16(data[4:])
+	// allocate memory & copy
+	buf := xmitBuf.Get().([]byte)[:len(data)-6]
+	copy(buf, data[6:])
+	pkt.data = buf
+	return pkt
+}
+
+// decode a fec packet
+func (dec *fecDecoder) decode(pkt fecPacket) (recovered [][]byte) {
+	// insertion
+	n := len(dec.rx) - 1
+	insertIdx := 0
+	for i := n; i >= 0; i-- {
+		if pkt.seqid == dec.rx[i].seqid { // de-duplicate
+			xmitBuf.Put(pkt.data)
+			return nil
+		} else if _itimediff(pkt.seqid, dec.rx[i].seqid) > 0 { // insertion
+			insertIdx = i + 1
+			break
+		}
+	}
+
+	// insert into ordered rx queue
+	if insertIdx == n+1 {
+		dec.rx = append(dec.rx, pkt)
+	} else {
+		dec.rx = append(dec.rx, fecPacket{})
+		copy(dec.rx[insertIdx+1:], dec.rx[insertIdx:]) // shift right
+		dec.rx[insertIdx] = pkt
+	}
+
+	// shard range for current packet
+	shardBegin := pkt.seqid - pkt.seqid%uint32(dec.shardSize)
+	shardEnd := shardBegin + uint32(dec.shardSize) - 1
+
+	// max search range in ordered queue for current shard
+	searchBegin := insertIdx - int(pkt.seqid%uint32(dec.shardSize))
+	if searchBegin < 0 {
+		searchBegin = 0
+	}
+	searchEnd := searchBegin + dec.shardSize - 1
+	if searchEnd >= len(dec.rx) {
+		searchEnd = len(dec.rx) - 1
+	}
+
+	// re-construct datashards
+	if searchEnd-searchBegin+1 >= dec.dataShards {
+		var numshard, numDataShard, first, maxlen int
+
+		// zero cache
+		shards := dec.decodeCache
+		shardsflag := dec.flagCache
+		for k := range dec.decodeCache {
+			shards[k] = nil
+			shardsflag[k] = false
+		}
+
+		// shard assembly
+		for i := searchBegin; i <= searchEnd; i++ {
+			seqid := dec.rx[i].seqid
+			if _itimediff(seqid, shardEnd) > 0 {
+				break
+			} else if _itimediff(seqid, shardBegin) >= 0 {
+				shards[seqid%uint32(dec.shardSize)] = dec.rx[i].data
+				shardsflag[seqid%uint32(dec.shardSize)] = true
+				numshard++
+				if dec.rx[i].flag == typeData {
+					numDataShard++
+				}
+				if numshard == 1 {
+					first = i
+				}
+				if len(dec.rx[i].data) > maxlen {
+					maxlen = len(dec.rx[i].data)
+				}
+			}
+		}
+
+		if numDataShard == dec.dataShards {
+			// case 1:  no lost data shards
+			dec.rx = dec.freeRange(first, numshard, dec.rx)
+		} else if numshard >= dec.dataShards {
+			// case 2: data shard lost, but  recoverable from parity shard
+			for k := range shards {
+				if shards[k] != nil {
+					dlen := len(shards[k])
+					shards[k] = shards[k][:maxlen]
+					xorBytes(shards[k][dlen:], shards[k][dlen:], shards[k][dlen:])
+				}
+			}
+			if err := dec.codec.ReconstructData(shards); err == nil {
+				for k := range shards[:dec.dataShards] {
+					if !shardsflag[k] {
+						recovered = append(recovered, shards[k])
+					}
+				}
+			}
+			dec.rx = dec.freeRange(first, numshard, dec.rx)
+		}
+	}
+
+	// keep rxlimit
+	if len(dec.rx) > dec.rxlimit {
+		if dec.rx[0].flag == typeData { // record unrecoverable data
+			atomic.AddUint64(&DefaultSnmp.FECShortShards, 1)
+		}
+		dec.rx = dec.freeRange(0, 1, dec.rx)
+	}
+	return
+}
+
+// free a range of fecPacket, and zero for GC recycling
+func (dec *fecDecoder) freeRange(first, n int, q []fecPacket) []fecPacket {
+	for i := first; i < first+n; i++ { // free
+		xmitBuf.Put(q[i].data)
+	}
+	copy(q[first:], q[first+n:])
+	for i := 0; i < n; i++ { // dereference data
+		q[len(q)-1-i].data = nil
+	}
+	return q[:len(q)-n]
+}
+
+type (
+	// fecEncoder for encoding outgoing packets
+	fecEncoder struct {
+		dataShards   int
+		parityShards int
+		shardSize    int
+		paws         uint32 // Protect Against Wrapped Sequence numbers
+		next         uint32 // next seqid
+
+		shardCount int // count the number of datashards collected
+		maxSize    int // record maximum data length in datashard
+
+		headerOffset  int // FEC header offset
+		payloadOffset int // FEC payload offset
+
+		// caches
+		shardCache  [][]byte
+		encodeCache [][]byte
+
+		// RS encoder
+		codec reedsolomon.Encoder
+	}
+)
+
+func newFECEncoder(dataShards, parityShards, offset int) *fecEncoder {
+	if dataShards <= 0 || parityShards <= 0 {
+		return nil
+	}
+	fec := new(fecEncoder)
+	fec.dataShards = dataShards
+	fec.parityShards = parityShards
+	fec.shardSize = dataShards + parityShards
+	fec.paws = (0xffffffff/uint32(fec.shardSize) - 1) * uint32(fec.shardSize)
+	fec.headerOffset = offset
+	fec.payloadOffset = fec.headerOffset + fecHeaderSize
+
+	enc, err := reedsolomon.New(dataShards, parityShards)
+	if err != nil {
+		return nil
+	}
+	fec.codec = enc
+
+	// caches
+	fec.encodeCache = make([][]byte, fec.shardSize)
+	fec.shardCache = make([][]byte, fec.shardSize)
+	for k := range fec.shardCache {
+		fec.shardCache[k] = make([]byte, mtuLimit)
+	}
+	return fec
+}
+
+// encode the packet, output parity shards if we have enough datashards
+// the content of returned parityshards will change in next encode
+func (enc *fecEncoder) encode(b []byte) (ps [][]byte) {
+	enc.markData(b[enc.headerOffset:])
+	binary.LittleEndian.PutUint16(b[enc.payloadOffset:], uint16(len(b[enc.payloadOffset:])))
+
+	// copy data to fec datashards
+	sz := len(b)
+	enc.shardCache[enc.shardCount] = enc.shardCache[enc.shardCount][:sz]
+	copy(enc.shardCache[enc.shardCount], b)
+	enc.shardCount++
+
+	// record max datashard length
+	if sz > enc.maxSize {
+		enc.maxSize = sz
+	}
+
+	//  calculate Reed-Solomon Erasure Code
+	if enc.shardCount == enc.dataShards {
+		// bzero each datashard's tail
+		for i := 0; i < enc.dataShards; i++ {
+			shard := enc.shardCache[i]
+			slen := len(shard)
+			xorBytes(shard[slen:enc.maxSize], shard[slen:enc.maxSize], shard[slen:enc.maxSize])
+		}
+
+		// construct equal-sized slice with stripped header
+		cache := enc.encodeCache
+		for k := range cache {
+			cache[k] = enc.shardCache[k][enc.payloadOffset:enc.maxSize]
+		}
+
+		// rs encode
+		if err := enc.codec.Encode(cache); err == nil {
+			ps = enc.shardCache[enc.dataShards:]
+			for k := range ps {
+				enc.markFEC(ps[k][enc.headerOffset:])
+				ps[k] = ps[k][:enc.maxSize]
+			}
+		}
+
+		// reset counters to zero
+		enc.shardCount = 0
+		enc.maxSize = 0
+	}
+
+	return
+}
+
+func (enc *fecEncoder) markData(data []byte) {
+	binary.LittleEndian.PutUint32(data, enc.next)
+	binary.LittleEndian.PutUint16(data[4:], typeData)
+	enc.next++
+}
+
+func (enc *fecEncoder) markFEC(data []byte) {
+	binary.LittleEndian.PutUint32(data, enc.next)
+	binary.LittleEndian.PutUint16(data[4:], typeFEC)
+	enc.next = (enc.next + 1) % enc.paws
+}

vendor/github.com/xtaci/kcp-go/kcp.go

@@ -0,0 +1,998 @@
+// Package kcp - A Fast and Reliable ARQ Protocol
+package kcp
+
+import (
+	"encoding/binary"
+	"sync/atomic"
+)
+
+const (
+	IKCP_RTO_NDL     = 30  // no delay min rto
+	IKCP_RTO_MIN     = 100 // normal min rto
+	IKCP_RTO_DEF     = 200
+	IKCP_RTO_MAX     = 60000
+	IKCP_CMD_PUSH    = 81 // cmd: push data
+	IKCP_CMD_ACK     = 82 // cmd: ack
+	IKCP_CMD_WASK    = 83 // cmd: window probe (ask)
+	IKCP_CMD_WINS    = 84 // cmd: window size (tell)
+	IKCP_ASK_SEND    = 1  // need to send IKCP_CMD_WASK
+	IKCP_ASK_TELL    = 2  // need to send IKCP_CMD_WINS
+	IKCP_WND_SND     = 32
+	IKCP_WND_RCV     = 32
+	IKCP_MTU_DEF     = 1400
+	IKCP_ACK_FAST    = 3
+	IKCP_INTERVAL    = 100
+	IKCP_OVERHEAD    = 24
+	IKCP_DEADLINK    = 20
+	IKCP_THRESH_INIT = 2
+	IKCP_THRESH_MIN  = 2
+	IKCP_PROBE_INIT  = 7000   // 7 secs to probe window size
+	IKCP_PROBE_LIMIT = 120000 // up to 120 secs to probe window
+)
+
+// output_callback is a prototype which ought capture conn and call conn.Write
+type output_callback func(buf []byte, size int)
+
+/* encode 8 bits unsigned int */
+func ikcp_encode8u(p []byte, c byte) []byte {
+	p[0] = c
+	return p[1:]
+}
+
+/* decode 8 bits unsigned int */
+func ikcp_decode8u(p []byte, c *byte) []byte {
+	*c = p[0]
+	return p[1:]
+}
+
+/* encode 16 bits unsigned int (lsb) */
+func ikcp_encode16u(p []byte, w uint16) []byte {
+	binary.LittleEndian.PutUint16(p, w)
+	return p[2:]
+}
+
+/* decode 16 bits unsigned int (lsb) */
+func ikcp_decode16u(p []byte, w *uint16) []byte {
+	*w = binary.LittleEndian.Uint16(p)
+	return p[2:]
+}
+
+/* encode 32 bits unsigned int (lsb) */
+func ikcp_encode32u(p []byte, l uint32) []byte {
+	binary.LittleEndian.PutUint32(p, l)
+	return p[4:]
+}
+
+/* decode 32 bits unsigned int (lsb) */
+func ikcp_decode32u(p []byte, l *uint32) []byte {
+	*l = binary.LittleEndian.Uint32(p)
+	return p[4:]
+}
+
+func _imin_(a, b uint32) uint32 {
+	if a <= b {
+		return a
+	}
+	return b
+}
+
+func _imax_(a, b uint32) uint32 {
+	if a >= b {
+		return a
+	}
+	return b
+}
+
+func _ibound_(lower, middle, upper uint32) uint32 {
+	return _imin_(_imax_(lower, middle), upper)
+}
+
+func _itimediff(later, earlier uint32) int32 {
+	return (int32)(later - earlier)
+}
+
+// segment defines a KCP segment
+type segment struct {
+	conv     uint32
+	cmd      uint8
+	frg      uint8
+	wnd      uint16
+	ts       uint32
+	sn       uint32
+	una      uint32
+	rto      uint32
+	xmit     uint32
+	resendts uint32
+	fastack  uint32
+	data     []byte
+}
+
+// encode a segment into buffer
+func (seg *segment) encode(ptr []byte) []byte {
+	ptr = ikcp_encode32u(ptr, seg.conv)
+	ptr = ikcp_encode8u(ptr, seg.cmd)
+	ptr = ikcp_encode8u(ptr, seg.frg)
+	ptr = ikcp_encode16u(ptr, seg.wnd)
+	ptr = ikcp_encode32u(ptr, seg.ts)
+	ptr = ikcp_encode32u(ptr, seg.sn)
+	ptr = ikcp_encode32u(ptr, seg.una)
+	ptr = ikcp_encode32u(ptr, uint32(len(seg.data)))
+	atomic.AddUint64(&DefaultSnmp.OutSegs, 1)
+	return ptr
+}
+
+// KCP defines a single KCP connection
+type KCP struct {
+	conv, mtu, mss, state                  uint32
+	snd_una, snd_nxt, rcv_nxt              uint32
+	ssthresh                               uint32
+	rx_rttvar, rx_srtt                     int32
+	rx_rto, rx_minrto                      uint32
+	snd_wnd, rcv_wnd, rmt_wnd, cwnd, probe uint32
+	interval, ts_flush                     uint32
+	nodelay, updated                       uint32
+	ts_probe, probe_wait                   uint32
+	dead_link, incr                        uint32
+
+	fastresend     int32
+	nocwnd, stream int32
+
+	snd_queue []segment
+	rcv_queue []segment
+	snd_buf   []segment
+	rcv_buf   []segment
+
+	acklist []ackItem
+
+	buffer []byte
+	output output_callback
+}
+
+type ackItem struct {
+	sn uint32
+	ts uint32
+}
+
+// NewKCP create a new kcp control object, 'conv' must equal in two endpoint
+// from the same connection.
+func NewKCP(conv uint32, output output_callback) *KCP {
+	kcp := new(KCP)
+	kcp.conv = conv
+	kcp.snd_wnd = IKCP_WND_SND
+	kcp.rcv_wnd = IKCP_WND_RCV
+	kcp.rmt_wnd = IKCP_WND_RCV
+	kcp.mtu = IKCP_MTU_DEF
+	kcp.mss = kcp.mtu - IKCP_OVERHEAD
+	kcp.buffer = make([]byte, (kcp.mtu+IKCP_OVERHEAD)*3)
+	kcp.rx_rto = IKCP_RTO_DEF
+	kcp.rx_minrto = IKCP_RTO_MIN
+	kcp.interval = IKCP_INTERVAL
+	kcp.ts_flush = IKCP_INTERVAL
+	kcp.ssthresh = IKCP_THRESH_INIT
+	kcp.dead_link = IKCP_DEADLINK
+	kcp.output = output
+	return kcp
+}
+
+// newSegment creates a KCP segment
+func (kcp *KCP) newSegment(size int) (seg segment) {
+	seg.data = xmitBuf.Get().([]byte)[:size]
+	return
+}
+
+// delSegment recycles a KCP segment
+func (kcp *KCP) delSegment(seg segment) {
+	xmitBuf.Put(seg.data)
+}
+
+// PeekSize checks the size of next message in the recv queue
+func (kcp *KCP) PeekSize() (length int) {
+	if len(kcp.rcv_queue) == 0 {
+		return -1
+	}
+
+	seg := &kcp.rcv_queue[0]
+	if seg.frg == 0 {
+		return len(seg.data)
+	}
+
+	if len(kcp.rcv_queue) < int(seg.frg+1) {
+		return -1
+	}
+
+	for k := range kcp.rcv_queue {
+		seg := &kcp.rcv_queue[k]
+		length += len(seg.data)
+		if seg.frg == 0 {
+			break
+		}
+	}
+	return
+}
+
+// Recv is user/upper level recv: returns size, returns below zero for EAGAIN
+func (kcp *KCP) Recv(buffer []byte) (n int) {
+	if len(kcp.rcv_queue) == 0 {
+		return -1
+	}
+
+	peeksize := kcp.PeekSize()
+	if peeksize < 0 {
+		return -2
+	}
+
+	if peeksize > len(buffer) {
+		return -3
+	}
+
+	var fast_recover bool
+	if len(kcp.rcv_queue) >= int(kcp.rcv_wnd) {
+		fast_recover = true
+	}
+
+	// merge fragment
+	count := 0
+	for k := range kcp.rcv_queue {
+		seg := &kcp.rcv_queue[k]
+		copy(buffer, seg.data)
+		buffer = buffer[len(seg.data):]
+		n += len(seg.data)
+		count++
+		kcp.delSegment(*seg)
+		if seg.frg == 0 {
+			break
+		}
+	}
+	if count > 0 {
+		kcp.rcv_queue = kcp.remove_front(kcp.rcv_queue, count)
+	}
+
+	// move available data from rcv_buf -> rcv_queue
+	count = 0
+	for k := range kcp.rcv_buf {
+		seg := &kcp.rcv_buf[k]
+		if seg.sn == kcp.rcv_nxt && len(kcp.rcv_queue) < int(kcp.rcv_wnd) {
+			kcp.rcv_nxt++
+			count++
+		} else {
+			break
+		}
+	}
+
+	if count > 0 {
+		kcp.rcv_queue = append(kcp.rcv_queue, kcp.rcv_buf[:count]...)
+		kcp.rcv_buf = kcp.remove_front(kcp.rcv_buf, count)
+	}
+
+	// fast recover
+	if len(kcp.rcv_queue) < int(kcp.rcv_wnd) && fast_recover {
+		// ready to send back IKCP_CMD_WINS in ikcp_flush
+		// tell remote my window size
+		kcp.probe |= IKCP_ASK_TELL
+	}
+	return
+}
+
+// Send is user/upper level send, returns below zero for error
+func (kcp *KCP) Send(buffer []byte) int {
+	var count int
+	if len(buffer) == 0 {
+		return -1
+	}
+
+	// append to previous segment in streaming mode (if possible)
+	if kcp.stream != 0 {
+		n := len(kcp.snd_queue)
+		if n > 0 {
+			seg := &kcp.snd_queue[n-1]
+			if len(seg.data) < int(kcp.mss) {
+				capacity := int(kcp.mss) - len(seg.data)
+				extend := capacity
+				if len(buffer) < capacity {
+					extend = len(buffer)
+				}
+
+				// grow slice, the underlying cap is guaranteed to
+				// be larger than kcp.mss
+				oldlen := len(seg.data)
+				seg.data = seg.data[:oldlen+extend]
+				copy(seg.data[oldlen:], buffer)
+				buffer = buffer[extend:]
+			}
+		}
+
+		if len(buffer) == 0 {
+			return 0
+		}
+	}
+
+	if len(buffer) <= int(kcp.mss) {
+		count = 1
+	} else {
+		count = (len(buffer) + int(kcp.mss) - 1) / int(kcp.mss)
+	}
+
+	if count > 255 {
+		return -2
+	}
+
+	if count == 0 {
+		count = 1
+	}
+
+	for i := 0; i < count; i++ {
+		var size int
+		if len(buffer) > int(kcp.mss) {
+			size = int(kcp.mss)
+		} else {
+			size = len(buffer)
+		}
+		seg := kcp.newSegment(size)
+		copy(seg.data, buffer[:size])
+		if kcp.stream == 0 { // message mode
+			seg.frg = uint8(count - i - 1)
+		} else { // stream mode
+			seg.frg = 0
+		}
+		kcp.snd_queue = append(kcp.snd_queue, seg)
+		buffer = buffer[size:]
+	}
+	return 0
+}
+
+func (kcp *KCP) update_ack(rtt int32) {
+	// https://tools.ietf.org/html/rfc6298
+	var rto uint32
+	if kcp.rx_srtt == 0 {
+		kcp.rx_srtt = rtt
+		kcp.rx_rttvar = rtt >> 1
+	} else {
+		delta := rtt - kcp.rx_srtt
+		kcp.rx_srtt += delta >> 3
+		if delta < 0 {
+			delta = -delta
+		}
+		if rtt < kcp.rx_srtt-kcp.rx_rttvar {
+			// if the new RTT sample is below the bottom of the range of
+			// what an RTT measurement is expected to be.
+			// give an 8x reduced weight versus its normal weighting
+			kcp.rx_rttvar += (delta - kcp.rx_rttvar) >> 5
+		} else {
+			kcp.rx_rttvar += (delta - kcp.rx_rttvar) >> 2
+		}
+	}
+	rto = uint32(kcp.rx_srtt) + _imax_(kcp.interval, uint32(kcp.rx_rttvar)<<2)
+	kcp.rx_rto = _ibound_(kcp.rx_minrto, rto, IKCP_RTO_MAX)
+}
+
+func (kcp *KCP) shrink_buf() {
+	if len(kcp.snd_buf) > 0 {
+		seg := &kcp.snd_buf[0]
+		kcp.snd_una = seg.sn
+	} else {
+		kcp.snd_una = kcp.snd_nxt
+	}
+}
+
+func (kcp *KCP) parse_ack(sn uint32) {
+	if _itimediff(sn, kcp.snd_una) < 0 || _itimediff(sn, kcp.snd_nxt) >= 0 {
+		return
+	}
+
+	for k := range kcp.snd_buf {
+		seg := &kcp.snd_buf[k]
+		if sn == seg.sn {
+			kcp.delSegment(*seg)
+			copy(kcp.snd_buf[k:], kcp.snd_buf[k+1:])
+			kcp.snd_buf[len(kcp.snd_buf)-1] = segment{}
+			kcp.snd_buf = kcp.snd_buf[:len(kcp.snd_buf)-1]
+			break
+		}
+		if _itimediff(sn, seg.sn) < 0 {
+			break
+		}
+	}
+}
+
+func (kcp *KCP) parse_fastack(sn uint32) {
+	if _itimediff(sn, kcp.snd_una) < 0 || _itimediff(sn, kcp.snd_nxt) >= 0 {
+		return
+	}
+
+	for k := range kcp.snd_buf {
+		seg := &kcp.snd_buf[k]
+		if _itimediff(sn, seg.sn) < 0 {
+			break
+		} else if sn != seg.sn {
+			seg.fastack++
+		}
+	}
+}
+
+func (kcp *KCP) parse_una(una uint32) {
+	count := 0
+	for k := range kcp.snd_buf {
+		seg := &kcp.snd_buf[k]
+		if _itimediff(una, seg.sn) > 0 {
+			kcp.delSegment(*seg)
+			count++
+		} else {
+			break
+		}
+	}
+	if count > 0 {
+		kcp.snd_buf = kcp.remove_front(kcp.snd_buf, count)
+	}
+}
+
+// ack append
+func (kcp *KCP) ack_push(sn, ts uint32) {
+	kcp.acklist = append(kcp.acklist, ackItem{sn, ts})
+}
+
+func (kcp *KCP) parse_data(newseg segment) {
+	sn := newseg.sn
+	if _itimediff(sn, kcp.rcv_nxt+kcp.rcv_wnd) >= 0 ||
+		_itimediff(sn, kcp.rcv_nxt) < 0 {
+		kcp.delSegment(newseg)
+		return
+	}
+
+	n := len(kcp.rcv_buf) - 1
+	insert_idx := 0
+	repeat := false
+	for i := n; i >= 0; i-- {
+		seg := &kcp.rcv_buf[i]
+		if seg.sn == sn {
+			repeat = true
+			atomic.AddUint64(&DefaultSnmp.RepeatSegs, 1)
+			break
+		}
+		if _itimediff(sn, seg.sn) > 0 {
+			insert_idx = i + 1
+			break
+		}
+	}
+
+	if !repeat {
+		if insert_idx == n+1 {
+			kcp.rcv_buf = append(kcp.rcv_buf, newseg)
+		} else {
+			kcp.rcv_buf = append(kcp.rcv_buf, segment{})
+			copy(kcp.rcv_buf[insert_idx+1:], kcp.rcv_buf[insert_idx:])
+			kcp.rcv_buf[insert_idx] = newseg
+		}
+	} else {
+		kcp.delSegment(newseg)
+	}
+
+	// move available data from rcv_buf -> rcv_queue
+	count := 0
+	for k := range kcp.rcv_buf {
+		seg := &kcp.rcv_buf[k]
+		if seg.sn == kcp.rcv_nxt && len(kcp.rcv_queue) < int(kcp.rcv_wnd) {
+			kcp.rcv_nxt++
+			count++
+		} else {
+			break
+		}
+	}
+	if count > 0 {
+		kcp.rcv_queue = append(kcp.rcv_queue, kcp.rcv_buf[:count]...)
+		kcp.rcv_buf = kcp.remove_front(kcp.rcv_buf, count)
+	}
+}
+
+// Input when you received a low level packet (eg. UDP packet), call it
+// regular indicates a regular packet has received(not from FEC)
+func (kcp *KCP) Input(data []byte, regular, ackNoDelay bool) int {
+	una := kcp.snd_una
+	if len(data) < IKCP_OVERHEAD {
+		return -1
+	}
+
+	var maxack uint32
+	var lastackts uint32
+	var flag int
+	var inSegs uint64
+
+	for {
+		var ts, sn, length, una, conv uint32
+		var wnd uint16
+		var cmd, frg uint8
+
+		if len(data) < int(IKCP_OVERHEAD) {
+			break
+		}
+
+		data = ikcp_decode32u(data, &conv)
+		if conv != kcp.conv {
+			return -1
+		}
+
+		data = ikcp_decode8u(data, &cmd)
+		data = ikcp_decode8u(data, &frg)
+		data = ikcp_decode16u(data, &wnd)
+		data = ikcp_decode32u(data, &ts)
+		data = ikcp_decode32u(data, &sn)
+		data = ikcp_decode32u(data, &una)
+		data = ikcp_decode32u(data, &length)
+		if len(data) < int(length) {
+			return -2
+		}
+
+		if cmd != IKCP_CMD_PUSH && cmd != IKCP_CMD_ACK &&
+			cmd != IKCP_CMD_WASK && cmd != IKCP_CMD_WINS {
+			return -3
+		}
+
+		// only trust window updates from regular packets. i.e: latest update
+		if regular {
+			kcp.rmt_wnd = uint32(wnd)
+		}
+		kcp.parse_una(una)
+		kcp.shrink_buf()
+
+		if cmd == IKCP_CMD_ACK {
+			kcp.parse_ack(sn)
+			kcp.shrink_buf()
+			if flag == 0 {
+				flag = 1
+				maxack = sn
+			} else if _itimediff(sn, maxack) > 0 {
+				maxack = sn
+			}
+			lastackts = ts
+		} else if cmd == IKCP_CMD_PUSH {
+			if _itimediff(sn, kcp.rcv_nxt+kcp.rcv_wnd) < 0 {
+				kcp.ack_push(sn, ts)
+				if _itimediff(sn, kcp.rcv_nxt) >= 0 {
+					seg := kcp.newSegment(int(length))
+					seg.conv = conv
+					seg.cmd = cmd
+					seg.frg = frg
+					seg.wnd = wnd
+					seg.ts = ts
+					seg.sn = sn
+					seg.una = una
+					copy(seg.data, data[:length])
+					kcp.parse_data(seg)
+				} else {
+					atomic.AddUint64(&DefaultSnmp.RepeatSegs, 1)
+				}
+			} else {
+				atomic.AddUint64(&DefaultSnmp.RepeatSegs, 1)
+			}
+		} else if cmd == IKCP_CMD_WASK {
+			// ready to send back IKCP_CMD_WINS in Ikcp_flush
+			// tell remote my window size
+			kcp.probe |= IKCP_ASK_TELL
+		} else if cmd == IKCP_CMD_WINS {
+			// do nothing
+		} else {
+			return -3
+		}
+
+		inSegs++
+		data = data[length:]
+	}
+	atomic.AddUint64(&DefaultSnmp.InSegs, inSegs)
+
+	if flag != 0 && regular {
+		kcp.parse_fastack(maxack)
+		current := currentMs()
+		if _itimediff(current, lastackts) >= 0 {
+			kcp.update_ack(_itimediff(current, lastackts))
+		}
+	}
+
+	if _itimediff(kcp.snd_una, una) > 0 {
+		if kcp.cwnd < kcp.rmt_wnd {
+			mss := kcp.mss
+			if kcp.cwnd < kcp.ssthresh {
+				kcp.cwnd++
+				kcp.incr += mss
+			} else {
+				if kcp.incr < mss {
+					kcp.incr = mss
+				}
+				kcp.incr += (mss*mss)/kcp.incr + (mss / 16)
+				if (kcp.cwnd+1)*mss <= kcp.incr {
+					kcp.cwnd++
+				}
+			}
+			if kcp.cwnd > kcp.rmt_wnd {
+				kcp.cwnd = kcp.rmt_wnd
+				kcp.incr = kcp.rmt_wnd * mss
+			}
+		}
+	}
+
+	if ackNoDelay && len(kcp.acklist) > 0 { // ack immediately
+		kcp.flush(true)
+	} else if kcp.rmt_wnd == 0 && len(kcp.acklist) > 0 { // window zero
+		kcp.flush(true)
+	}
+	return 0
+}
+
+func (kcp *KCP) wnd_unused() uint16 {
+	if len(kcp.rcv_queue) < int(kcp.rcv_wnd) {
+		return uint16(int(kcp.rcv_wnd) - len(kcp.rcv_queue))
+	}
+	return 0
+}
+
+// flush pending data
+func (kcp *KCP) flush(ackOnly bool) {
+	var seg segment
+	seg.conv = kcp.conv
+	seg.cmd = IKCP_CMD_ACK
+	seg.wnd = kcp.wnd_unused()
+	seg.una = kcp.rcv_nxt
+
+	buffer := kcp.buffer
+	// flush acknowledges
+	ptr := buffer
+	for i, ack := range kcp.acklist {
+		size := len(buffer) - len(ptr)
+		if size+IKCP_OVERHEAD > int(kcp.mtu) {
+			kcp.output(buffer, size)
+			ptr = buffer
+		}
+		// filter jitters caused by bufferbloat
+		if ack.sn >= kcp.rcv_nxt || len(kcp.acklist)-1 == i {
+			seg.sn, seg.ts = ack.sn, ack.ts
+			ptr = seg.encode(ptr)
+		}
+	}
+	kcp.acklist = kcp.acklist[0:0]
+
+	if ackOnly { // flash remain ack segments
+		size := len(buffer) - len(ptr)
+		if size > 0 {
+			kcp.output(buffer, size)
+		}
+		return
+	}
+
+	// probe window size (if remote window size equals zero)
+	if kcp.rmt_wnd == 0 {
+		current := currentMs()
+		if kcp.probe_wait == 0 {
+			kcp.probe_wait = IKCP_PROBE_INIT
+			kcp.ts_probe = current + kcp.probe_wait
+		} else {
+			if _itimediff(current, kcp.ts_probe) >= 0 {
+				if kcp.probe_wait < IKCP_PROBE_INIT {
+					kcp.probe_wait = IKCP_PROBE_INIT
+				}
+				kcp.probe_wait += kcp.probe_wait / 2
+				if kcp.probe_wait > IKCP_PROBE_LIMIT {
+					kcp.probe_wait = IKCP_PROBE_LIMIT
+				}
+				kcp.ts_probe = current + kcp.probe_wait
+				kcp.probe |= IKCP_ASK_SEND
+			}
+		}
+	} else {
+		kcp.ts_probe = 0
+		kcp.probe_wait = 0
+	}
+
+	// flush window probing commands
+	if (kcp.probe & IKCP_ASK_SEND) != 0 {
+		seg.cmd = IKCP_CMD_WASK
+		size := len(buffer) - len(ptr)
+		if size+IKCP_OVERHEAD > int(kcp.mtu) {
+			kcp.output(buffer, size)
+			ptr = buffer
+		}
+		ptr = seg.encode(ptr)
+	}
+
+	// flush window probing commands
+	if (kcp.probe & IKCP_ASK_TELL) != 0 {
+		seg.cmd = IKCP_CMD_WINS
+		size := len(buffer) - len(ptr)
+		if size+IKCP_OVERHEAD > int(kcp.mtu) {
+			kcp.output(buffer, size)
+			ptr = buffer
+		}
+		ptr = seg.encode(ptr)
+	}
+
+	kcp.probe = 0
+
+	// calculate window size
+	cwnd := _imin_(kcp.snd_wnd, kcp.rmt_wnd)
+	if kcp.nocwnd == 0 {
+		cwnd = _imin_(kcp.cwnd, cwnd)
+	}
+
+	// sliding window, controlled by snd_nxt && sna_una+cwnd
+	newSegsCount := 0
+	for k := range kcp.snd_queue {
+		if _itimediff(kcp.snd_nxt, kcp.snd_una+cwnd) >= 0 {
+			break
+		}
+		newseg := kcp.snd_queue[k]
+		newseg.conv = kcp.conv
+		newseg.cmd = IKCP_CMD_PUSH
+		newseg.sn = kcp.snd_nxt
+		kcp.snd_buf = append(kcp.snd_buf, newseg)
+		kcp.snd_nxt++
+		newSegsCount++
+		kcp.snd_queue[k].data = nil
+	}
+	if newSegsCount > 0 {
+		kcp.snd_queue = kcp.remove_front(kcp.snd_queue, newSegsCount)
+	}
+
+	// calculate resent
+	resent := uint32(kcp.fastresend)
+	if kcp.fastresend <= 0 {
+		resent = 0xffffffff
+	}
+
+	// check for retransmissions
+	current := currentMs()
+	var change, lost, lostSegs, fastRetransSegs, earlyRetransSegs uint64
+	for k := range kcp.snd_buf {
+		segment := &kcp.snd_buf[k]
+		needsend := false
+		if segment.xmit == 0 { // initial transmit
+			needsend = true
+			segment.rto = kcp.rx_rto
+			segment.resendts = current + segment.rto
+		} else if _itimediff(current, segment.resendts) >= 0 { // RTO
+			needsend = true
+			if kcp.nodelay == 0 {
+				segment.rto += kcp.rx_rto
+			} else {
+				segment.rto += kcp.rx_rto / 2
+			}
+			segment.resendts = current + segment.rto
+			lost++
+			lostSegs++
+		} else if segment.fastack >= resent { // fast retransmit
+			needsend = true
+			segment.fastack = 0
+			segment.rto = kcp.rx_rto
+			segment.resendts = current + segment.rto
+			change++
+			fastRetransSegs++
+		} else if segment.fastack > 0 && newSegsCount == 0 { // early retransmit
+			needsend = true
+			segment.fastack = 0
+			segment.rto = kcp.rx_rto
+			segment.resendts = current + segment.rto
+			change++
+			earlyRetransSegs++
+		}
+
+		if needsend {
+			segment.xmit++
+			segment.ts = current
+			segment.wnd = seg.wnd
+			segment.una = seg.una
+
+			size := len(buffer) - len(ptr)
+			need := IKCP_OVERHEAD + len(segment.data)
+
+			if size+need > int(kcp.mtu) {
+				kcp.output(buffer, size)
+				current = currentMs() // time update for a blocking call
+				ptr = buffer
+			}
+
+			ptr = segment.encode(ptr)
+			copy(ptr, segment.data)
+			ptr = ptr[len(segment.data):]
+
+			if segment.xmit >= kcp.dead_link {
+				kcp.state = 0xFFFFFFFF
+			}
+		}
+	}
+
+	// flash remain segments
+	size := len(buffer) - len(ptr)
+	if size > 0 {
+		kcp.output(buffer, size)
+	}
+
+	// counter updates
+	sum := lostSegs
+	if lostSegs > 0 {
+		atomic.AddUint64(&DefaultSnmp.LostSegs, lostSegs)
+	}
+	if fastRetransSegs > 0 {
+		atomic.AddUint64(&DefaultSnmp.FastRetransSegs, fastRetransSegs)
+		sum += fastRetransSegs
+	}
+	if earlyRetransSegs > 0 {
+		atomic.AddUint64(&DefaultSnmp.EarlyRetransSegs, earlyRetransSegs)
+		sum += earlyRetransSegs
+	}
+	if sum > 0 {
+		atomic.AddUint64(&DefaultSnmp.RetransSegs, sum)
+	}
+
+	// update ssthresh
+	// rate halving, https://tools.ietf.org/html/rfc6937
+	if change > 0 {
+		inflight := kcp.snd_nxt - kcp.snd_una
+		kcp.ssthresh = inflight / 2
+		if kcp.ssthresh < IKCP_THRESH_MIN {
+			kcp.ssthresh = IKCP_THRESH_MIN
+		}
+		kcp.cwnd = kcp.ssthresh + resent
+		kcp.incr = kcp.cwnd * kcp.mss
+	}
+
+	// congestion control, https://tools.ietf.org/html/rfc5681
+	if lost > 0 {
+		kcp.ssthresh = cwnd / 2
+		if kcp.ssthresh < IKCP_THRESH_MIN {
+			kcp.ssthresh = IKCP_THRESH_MIN
+		}
+		kcp.cwnd = 1
+		kcp.incr = kcp.mss
+	}
+
+	if kcp.cwnd < 1 {
+		kcp.cwnd = 1
+		kcp.incr = kcp.mss
+	}
+}
+
+// Update updates state (call it repeatedly, every 10ms-100ms), or you can ask
+// ikcp_check when to call it again (without ikcp_input/_send calling).
+// 'current' - current timestamp in millisec.
+func (kcp *KCP) Update() {
+	var slap int32
+
+	current := currentMs()
+	if kcp.updated == 0 {
+		kcp.updated = 1
+		kcp.ts_flush = current
+	}
+
+	slap = _itimediff(current, kcp.ts_flush)
+
+	if slap >= 10000 || slap < -10000 {
+		kcp.ts_flush = current
+		slap = 0
+	}
+
+	if slap >= 0 {
+		kcp.ts_flush += kcp.interval
+		if _itimediff(current, kcp.ts_flush) >= 0 {
+			kcp.ts_flush = current + kcp.interval
+		}
+		kcp.flush(false)
+	}
+}
+
+// Check determines when should you invoke ikcp_update:
+// returns when you should invoke ikcp_update in millisec, if there
+// is no ikcp_input/_send calling. you can call ikcp_update in that
+// time, instead of call update repeatly.
+// Important to reduce unnacessary ikcp_update invoking. use it to
+// schedule ikcp_update (eg. implementing an epoll-like mechanism,
+// or optimize ikcp_update when handling massive kcp connections)
+func (kcp *KCP) Check() uint32 {
+	current := currentMs()
+	ts_flush := kcp.ts_flush
+	tm_flush := int32(0x7fffffff)
+	tm_packet := int32(0x7fffffff)
+	minimal := uint32(0)
+	if kcp.updated == 0 {
+		return current
+	}
+
+	if _itimediff(current, ts_flush) >= 10000 ||
+		_itimediff(current, ts_flush) < -10000 {
+		ts_flush = current
+	}
+
+	if _itimediff(current, ts_flush) >= 0 {
+		return current
+	}
+
+	tm_flush = _itimediff(ts_flush, current)
+
+	for k := range kcp.snd_buf {
+		seg := &kcp.snd_buf[k]
+		diff := _itimediff(seg.resendts, current)
+		if diff <= 0 {
+			return current
+		}
+		if diff < tm_packet {
+			tm_packet = diff
+		}
+	}
+
+	minimal = uint32(tm_packet)
+	if tm_packet >= tm_flush {
+		minimal = uint32(tm_flush)
+	}
+	if minimal >= kcp.interval {
+		minimal = kcp.interval
+	}
+
+	return current + minimal
+}
+
+// SetMtu changes MTU size, default is 1400
+func (kcp *KCP) SetMtu(mtu int) int {
+	if mtu < 50 || mtu < IKCP_OVERHEAD {
+		return -1
+	}
+	buffer := make([]byte, (mtu+IKCP_OVERHEAD)*3)
+	if buffer == nil {
+		return -2
+	}
+	kcp.mtu = uint32(mtu)
+	kcp.mss = kcp.mtu - IKCP_OVERHEAD
+	kcp.buffer = buffer
+	return 0
+}
+
+// NoDelay options
+// fastest: ikcp_nodelay(kcp, 1, 20, 2, 1)
+// nodelay: 0:disable(default), 1:enable
+// interval: internal update timer interval in millisec, default is 100ms
+// resend: 0:disable fast resend(default), 1:enable fast resend
+// nc: 0:normal congestion control(default), 1:disable congestion control
+func (kcp *KCP) NoDelay(nodelay, interval, resend, nc int) int {
+	if nodelay >= 0 {
+		kcp.nodelay = uint32(nodelay)
+		if nodelay != 0 {
+			kcp.rx_minrto = IKCP_RTO_NDL
+		} else {
+			kcp.rx_minrto = IKCP_RTO_MIN
+		}
+	}
+	if interval >= 0 {
+		if interval > 5000 {
+			interval = 5000
+		} else if interval < 10 {
+			interval = 10
+		}
+		kcp.interval = uint32(interval)
+	}
+	if resend >= 0 {
+		kcp.fastresend = int32(resend)
+	}
+	if nc >= 0 {
+		kcp.nocwnd = int32(nc)
+	}
+	return 0
+}
+
+// WndSize sets maximum window size: sndwnd=32, rcvwnd=32 by default
+func (kcp *KCP) WndSize(sndwnd, rcvwnd int) int {
+	if sndwnd > 0 {
+		kcp.snd_wnd = uint32(sndwnd)
+	}
+	if rcvwnd > 0 {
+		kcp.rcv_wnd = uint32(rcvwnd)
+	}
+	return 0
+}
+
+// WaitSnd gets how many packet is waiting to be sent
+func (kcp *KCP) WaitSnd() int {
+	return len(kcp.snd_buf) + len(kcp.snd_queue)
+}
+
+// remove front n elements from queue
+func (kcp *KCP) remove_front(q []segment, n int) []segment {
+	newn := copy(q, q[n:])
+	for i := newn; i < len(q); i++ {
+		q[i] = segment{} // manual set nil for GC
+	}
+	return q[:newn]
+}

vendor/github.com/xtaci/kcp-go/sess.go

@@ -0,0 +1,961 @@
+package kcp
+
+import (
+	"crypto/rand"
+	"encoding/binary"
+	"hash/crc32"
+	"io"
+	"net"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/pkg/errors"
+	"golang.org/x/net/ipv4"
+)
+
+type errTimeout struct {
+	error
+}
+
+func (errTimeout) Timeout() bool   { return true }
+func (errTimeout) Temporary() bool { return true }
+func (errTimeout) Error() string   { return "i/o timeout" }
+
+const (
+	// 16-bytes magic number for each packet
+	nonceSize = 16
+
+	// 4-bytes packet checksum
+	crcSize = 4
+
+	// overall crypto header size
+	cryptHeaderSize = nonceSize + crcSize
+
+	// maximum packet size
+	mtuLimit = 1500
+
+	// FEC keeps rxFECMulti* (dataShard+parityShard) ordered packets in memory
+	rxFECMulti = 3
+
+	// accept backlog
+	acceptBacklog = 128
+
+	// prerouting(to session) queue
+	qlen = 128
+)
+
+const (
+	errBrokenPipe       = "broken pipe"
+	errInvalidOperation = "invalid operation"
+)
+
+var (
+	// global packet buffer
+	// shared among sending/receiving/FEC
+	xmitBuf sync.Pool
+)
+
+func init() {
+	xmitBuf.New = func() interface{} {
+		return make([]byte, mtuLimit)
+	}
+}
+
+type (
+	// UDPSession defines a KCP session implemented by UDP
+	UDPSession struct {
+		updaterIdx int            // record slice index in updater
+		conn       net.PacketConn // the underlying packet connection
+		kcp        *KCP           // KCP ARQ protocol
+		l          *Listener      // point to the Listener if it's accepted by Listener
+		block      BlockCrypt     // block encryption
+
+		// kcp receiving is based on packets
+		// recvbuf turns packets into stream
+		recvbuf []byte
+		bufptr  []byte
+		// extended output buffer(with header)
+		ext []byte
+
+		// FEC
+		fecDecoder *fecDecoder
+		fecEncoder *fecEncoder
+
+		// settings
+		remote     net.Addr  // remote peer address
+		rd         time.Time // read deadline
+		wd         time.Time // write deadline
+		headerSize int       // the overall header size added before KCP frame
+		ackNoDelay bool      // send ack immediately for each incoming packet
+		writeDelay bool      // delay kcp.flush() for Write() for bulk transfer
+		dup        int       // duplicate udp packets
+
+		// notifications
+		die          chan struct{} // notify session has Closed
+		chReadEvent  chan struct{} // notify Read() can be called without blocking
+		chWriteEvent chan struct{} // notify Write() can be called without blocking
+		chErrorEvent chan error    // notify Read() have an error
+
+		isClosed bool // flag the session has Closed
+		mu       sync.Mutex
+	}
+
+	setReadBuffer interface {
+		SetReadBuffer(bytes int) error
+	}
+
+	setWriteBuffer interface {
+		SetWriteBuffer(bytes int) error
+	}
+)
+
+// newUDPSession create a new udp session for client or server
+func newUDPSession(conv uint32, dataShards, parityShards int, l *Listener, conn net.PacketConn, remote net.Addr, block BlockCrypt) *UDPSession {
+	sess := new(UDPSession)
+	sess.die = make(chan struct{})
+	sess.chReadEvent = make(chan struct{}, 1)
+	sess.chWriteEvent = make(chan struct{}, 1)
+	sess.chErrorEvent = make(chan error, 1)
+	sess.remote = remote
+	sess.conn = conn
+	sess.l = l
+	sess.block = block
+	sess.recvbuf = make([]byte, mtuLimit)
+
+	// FEC initialization
+	sess.fecDecoder = newFECDecoder(rxFECMulti*(dataShards+parityShards), dataShards, parityShards)
+	if sess.block != nil {
+		sess.fecEncoder = newFECEncoder(dataShards, parityShards, cryptHeaderSize)
+	} else {
+		sess.fecEncoder = newFECEncoder(dataShards, parityShards, 0)
+	}
+
+	// calculate header size
+	if sess.block != nil {
+		sess.headerSize += cryptHeaderSize
+	}
+	if sess.fecEncoder != nil {
+		sess.headerSize += fecHeaderSizePlus2
+	}
+
+	// only allocate extended packet buffer
+	// when the extra header is required
+	if sess.headerSize > 0 {
+		sess.ext = make([]byte, mtuLimit)
+	}
+
+	sess.kcp = NewKCP(conv, func(buf []byte, size int) {
+		if size >= IKCP_OVERHEAD {
+			sess.output(buf[:size])
+		}
+	})
+	sess.kcp.SetMtu(IKCP_MTU_DEF - sess.headerSize)
+
+	// add current session to the global updater,
+	// which periodically calls sess.update()
+	updater.addSession(sess)
+
+	if sess.l == nil { // it's a client connection
+		go sess.readLoop()
+		atomic.AddUint64(&DefaultSnmp.ActiveOpens, 1)
+	} else {
+		atomic.AddUint64(&DefaultSnmp.PassiveOpens, 1)
+	}
+	currestab := atomic.AddUint64(&DefaultSnmp.CurrEstab, 1)
+	maxconn := atomic.LoadUint64(&DefaultSnmp.MaxConn)
+	if currestab > maxconn {
+		atomic.CompareAndSwapUint64(&DefaultSnmp.MaxConn, maxconn, currestab)
+	}
+
+	return sess
+}
+
+// Read implements net.Conn
+func (s *UDPSession) Read(b []byte) (n int, err error) {
+	for {
+		s.mu.Lock()
+		if len(s.bufptr) > 0 { // copy from buffer into b
+			n = copy(b, s.bufptr)
+			s.bufptr = s.bufptr[n:]
+			s.mu.Unlock()
+			return n, nil
+		}
+
+		if s.isClosed {
+			s.mu.Unlock()
+			return 0, errors.New(errBrokenPipe)
+		}
+
+		if size := s.kcp.PeekSize(); size > 0 { // peek data size from kcp
+			atomic.AddUint64(&DefaultSnmp.BytesReceived, uint64(size))
+			if len(b) >= size { // direct write to b
+				s.kcp.Recv(b)
+				s.mu.Unlock()
+				return size, nil
+			}
+
+			// resize kcp receive buffer
+			// to make sure recvbuf has enough capacity
+			if cap(s.recvbuf) < size {
+				s.recvbuf = make([]byte, size)
+			}
+
+			// resize recvbuf slice length
+			s.recvbuf = s.recvbuf[:size]
+			s.kcp.Recv(s.recvbuf)
+			n = copy(b, s.recvbuf)   // copy to b
+			s.bufptr = s.recvbuf[n:] // update pointer
+			s.mu.Unlock()
+			return n, nil
+		}
+
+		// read deadline
+		var timeout *time.Timer
+		var c <-chan time.Time
+		if !s.rd.IsZero() {
+			if time.Now().After(s.rd) {
+				s.mu.Unlock()
+				return 0, errTimeout{}
+			}
+
+			delay := s.rd.Sub(time.Now())
+			timeout = time.NewTimer(delay)
+			c = timeout.C
+		}
+		s.mu.Unlock()
+
+		// wait for read event or timeout
+		select {
+		case <-s.chReadEvent:
+		case <-c:
+		case <-s.die:
+		case err = <-s.chErrorEvent:
+			if timeout != nil {
+				timeout.Stop()
+			}
+			return n, err
+		}
+
+		if timeout != nil {
+			timeout.Stop()
+		}
+	}
+}
+
+// Write implements net.Conn
+func (s *UDPSession) Write(b []byte) (n int, err error) {
+	for {
+		s.mu.Lock()
+		if s.isClosed {
+			s.mu.Unlock()
+			return 0, errors.New(errBrokenPipe)
+		}
+
+		// api flow control
+		if s.kcp.WaitSnd() < int(s.kcp.snd_wnd) {
+			n = len(b)
+			for {
+				if len(b) <= int(s.kcp.mss) {
+					s.kcp.Send(b)
+					break
+				} else {
+					s.kcp.Send(b[:s.kcp.mss])
+					b = b[s.kcp.mss:]
+				}
+			}
+
+			if !s.writeDelay {
+				s.kcp.flush(false)
+			}
+			s.mu.Unlock()
+			atomic.AddUint64(&DefaultSnmp.BytesSent, uint64(n))
+			return n, nil
+		}
+
+		// write deadline
+		var timeout *time.Timer
+		var c <-chan time.Time
+		if !s.wd.IsZero() {
+			if time.Now().After(s.wd) {
+				s.mu.Unlock()
+				return 0, errTimeout{}
+			}
+			delay := s.wd.Sub(time.Now())
+			timeout = time.NewTimer(delay)
+			c = timeout.C
+		}
+		s.mu.Unlock()
+
+		// wait for write event or timeout
+		select {
+		case <-s.chWriteEvent:
+		case <-c:
+		case <-s.die:
+		}
+
+		if timeout != nil {
+			timeout.Stop()
+		}
+	}
+}
+
+// Close closes the connection.
+func (s *UDPSession) Close() error {
+	// remove this session from updater & listener(if necessary)
+	updater.removeSession(s)
+	if s.l != nil { // notify listener
+		s.l.closeSession(sessionKey{
+			addr:   s.remote.String(),
+			convID: s.kcp.conv,
+		})
+	}
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.isClosed {
+		return errors.New(errBrokenPipe)
+	}
+	close(s.die)
+	s.isClosed = true
+	atomic.AddUint64(&DefaultSnmp.CurrEstab, ^uint64(0))
+	if s.l == nil { // client socket close
+		return s.conn.Close()
+	}
+	return nil
+}
+
+// LocalAddr returns the local network address. The Addr returned is shared by all invocations of LocalAddr, so do not modify it.
+func (s *UDPSession) LocalAddr() net.Addr { return s.conn.LocalAddr() }
+
+// RemoteAddr returns the remote network address. The Addr returned is shared by all invocations of RemoteAddr, so do not modify it.
+func (s *UDPSession) RemoteAddr() net.Addr { return s.remote }
+
+// SetDeadline sets the deadline associated with the listener. A zero time value disables the deadline.
+func (s *UDPSession) SetDeadline(t time.Time) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.rd = t
+	s.wd = t
+	return nil
+}
+
+// SetReadDeadline implements the Conn SetReadDeadline method.
+func (s *UDPSession) SetReadDeadline(t time.Time) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.rd = t
+	return nil
+}
+
+// SetWriteDeadline implements the Conn SetWriteDeadline method.
+func (s *UDPSession) SetWriteDeadline(t time.Time) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.wd = t
+	return nil
+}
+
+// SetWriteDelay delays write for bulk transfer until the next update interval
+func (s *UDPSession) SetWriteDelay(delay bool) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.writeDelay = delay
+}
+
+// SetWindowSize set maximum window size
+func (s *UDPSession) SetWindowSize(sndwnd, rcvwnd int) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.kcp.WndSize(sndwnd, rcvwnd)
+}
+
+// SetMtu sets the maximum transmission unit(not including UDP header)
+func (s *UDPSession) SetMtu(mtu int) bool {
+	if mtu > mtuLimit {
+		return false
+	}
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.kcp.SetMtu(mtu - s.headerSize)
+	return true
+}
+
+// SetStreamMode toggles the stream mode on/off
+func (s *UDPSession) SetStreamMode(enable bool) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if enable {
+		s.kcp.stream = 1
+	} else {
+		s.kcp.stream = 0
+	}
+}
+
+// SetACKNoDelay changes ack flush option, set true to flush ack immediately,
+func (s *UDPSession) SetACKNoDelay(nodelay bool) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.ackNoDelay = nodelay
+}
+
+// SetDUP duplicates udp packets for kcp output, for testing purpose only
+func (s *UDPSession) SetDUP(dup int) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.dup = dup
+}
+
+// SetNoDelay calls nodelay() of kcp
+// https://github.com/skywind3000/kcp/blob/master/README.en.md#protocol-configuration
+func (s *UDPSession) SetNoDelay(nodelay, interval, resend, nc int) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.kcp.NoDelay(nodelay, interval, resend, nc)
+}
+
+// SetDSCP sets the 6bit DSCP field of IP header, no effect if it's accepted from Listener
+func (s *UDPSession) SetDSCP(dscp int) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.l == nil {
+		if nc, ok := s.conn.(*connectedUDPConn); ok {
+			return ipv4.NewConn(nc.UDPConn).SetTOS(dscp << 2)
+		} else if nc, ok := s.conn.(net.Conn); ok {
+			return ipv4.NewConn(nc).SetTOS(dscp << 2)
+		}
+	}
+	return errors.New(errInvalidOperation)
+}
+
+// SetReadBuffer sets the socket read buffer, no effect if it's accepted from Listener
+func (s *UDPSession) SetReadBuffer(bytes int) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.l == nil {
+		if nc, ok := s.conn.(setReadBuffer); ok {
+			return nc.SetReadBuffer(bytes)
+		}
+	}
+	return errors.New(errInvalidOperation)
+}
+
+// SetWriteBuffer sets the socket write buffer, no effect if it's accepted from Listener
+func (s *UDPSession) SetWriteBuffer(bytes int) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.l == nil {
+		if nc, ok := s.conn.(setWriteBuffer); ok {
+			return nc.SetWriteBuffer(bytes)
+		}
+	}
+	return errors.New(errInvalidOperation)
+}
+
+// output pipeline entry
+// steps for output data processing:
+// 0. Header extends
+// 1. FEC
+// 2. CRC32
+// 3. Encryption
+// 4. WriteTo kernel
+func (s *UDPSession) output(buf []byte) {
+	var ecc [][]byte
+
+	// 0. extend buf's header space(if necessary)
+	ext := buf
+	if s.headerSize > 0 {
+		ext = s.ext[:s.headerSize+len(buf)]
+		copy(ext[s.headerSize:], buf)
+	}
+
+	// 1. FEC encoding
+	if s.fecEncoder != nil {
+		ecc = s.fecEncoder.encode(ext)
+	}
+
+	// 2&3. crc32 & encryption
+	if s.block != nil {
+		io.ReadFull(rand.Reader, ext[:nonceSize])
+		checksum := crc32.ChecksumIEEE(ext[cryptHeaderSize:])
+		binary.LittleEndian.PutUint32(ext[nonceSize:], checksum)
+		s.block.Encrypt(ext, ext)
+
+		for k := range ecc {
+			io.ReadFull(rand.Reader, ecc[k][:nonceSize])
+			checksum := crc32.ChecksumIEEE(ecc[k][cryptHeaderSize:])
+			binary.LittleEndian.PutUint32(ecc[k][nonceSize:], checksum)
+			s.block.Encrypt(ecc[k], ecc[k])
+		}
+	}
+
+	// 4. WriteTo kernel
+	nbytes := 0
+	npkts := 0
+	for i := 0; i < s.dup+1; i++ {
+		if n, err := s.conn.WriteTo(ext, s.remote); err == nil {
+			nbytes += n
+			npkts++
+		}
+	}
+
+	for k := range ecc {
+		if n, err := s.conn.WriteTo(ecc[k], s.remote); err == nil {
+			nbytes += n
+			npkts++
+		}
+	}
+	atomic.AddUint64(&DefaultSnmp.OutPkts, uint64(npkts))
+	atomic.AddUint64(&DefaultSnmp.OutBytes, uint64(nbytes))
+}
+
+// kcp update, returns interval for next calling
+func (s *UDPSession) update() (interval time.Duration) {
+	s.mu.Lock()
+	s.kcp.flush(false)
+	if s.kcp.WaitSnd() < int(s.kcp.snd_wnd) {
+		s.notifyWriteEvent()
+	}
+	interval = time.Duration(s.kcp.interval) * time.Millisecond
+	s.mu.Unlock()
+	return
+}
+
+// GetConv gets conversation id of a session
+func (s *UDPSession) GetConv() uint32 { return s.kcp.conv }
+
+func (s *UDPSession) notifyReadEvent() {
+	select {
+	case s.chReadEvent <- struct{}{}:
+	default:
+	}
+}
+
+func (s *UDPSession) notifyWriteEvent() {
+	select {
+	case s.chWriteEvent <- struct{}{}:
+	default:
+	}
+}
+
+func (s *UDPSession) kcpInput(data []byte) {
+	var kcpInErrors, fecErrs, fecRecovered, fecParityShards uint64
+
+	if s.fecDecoder != nil {
+		f := s.fecDecoder.decodeBytes(data)
+		s.mu.Lock()
+		if f.flag == typeData {
+			if ret := s.kcp.Input(data[fecHeaderSizePlus2:], true, s.ackNoDelay); ret != 0 {
+				kcpInErrors++
+			}
+		}
+
+		if f.flag == typeData || f.flag == typeFEC {
+			if f.flag == typeFEC {
+				fecParityShards++
+			}
+
+			recovers := s.fecDecoder.decode(f)
+			for _, r := range recovers {
+				if len(r) >= 2 { // must be larger than 2bytes
+					sz := binary.LittleEndian.Uint16(r)
+					if int(sz) <= len(r) && sz >= 2 {
+						if ret := s.kcp.Input(r[2:sz], false, s.ackNoDelay); ret == 0 {
+							fecRecovered++
+						} else {
+							kcpInErrors++
+						}
+					} else {
+						fecErrs++
+					}
+				} else {
+					fecErrs++
+				}
+			}
+		}
+
+		// notify reader
+		if n := s.kcp.PeekSize(); n > 0 {
+			s.notifyReadEvent()
+		}
+		s.mu.Unlock()
+	} else {
+		s.mu.Lock()
+		if ret := s.kcp.Input(data, true, s.ackNoDelay); ret != 0 {
+			kcpInErrors++
+		}
+		// notify reader
+		if n := s.kcp.PeekSize(); n > 0 {
+			s.notifyReadEvent()
+		}
+		s.mu.Unlock()
+	}
+
+	atomic.AddUint64(&DefaultSnmp.InPkts, 1)
+	atomic.AddUint64(&DefaultSnmp.InBytes, uint64(len(data)))
+	if fecParityShards > 0 {
+		atomic.AddUint64(&DefaultSnmp.FECParityShards, fecParityShards)
+	}
+	if kcpInErrors > 0 {
+		atomic.AddUint64(&DefaultSnmp.KCPInErrors, kcpInErrors)
+	}
+	if fecErrs > 0 {
+		atomic.AddUint64(&DefaultSnmp.FECErrs, fecErrs)
+	}
+	if fecRecovered > 0 {
+		atomic.AddUint64(&DefaultSnmp.FECRecovered, fecRecovered)
+	}
+}
+
+func (s *UDPSession) receiver(ch chan<- []byte) {
+	for {
+		data := xmitBuf.Get().([]byte)[:mtuLimit]
+		if n, _, err := s.conn.ReadFrom(data); err == nil && n >= s.headerSize+IKCP_OVERHEAD {
+			select {
+			case ch <- data[:n]:
+			case <-s.die:
+				return
+			}
+		} else if err != nil {
+			s.chErrorEvent <- err
+			return
+		} else {
+			atomic.AddUint64(&DefaultSnmp.InErrs, 1)
+		}
+	}
+}
+
+// read loop for client session
+func (s *UDPSession) readLoop() {
+	chPacket := make(chan []byte, qlen)
+	go s.receiver(chPacket)
+
+	for {
+		select {
+		case data := <-chPacket:
+			raw := data
+			dataValid := false
+			if s.block != nil {
+				s.block.Decrypt(data, data)
+				data = data[nonceSize:]
+				checksum := crc32.ChecksumIEEE(data[crcSize:])
+				if checksum == binary.LittleEndian.Uint32(data) {
+					data = data[crcSize:]
+					dataValid = true
+				} else {
+					atomic.AddUint64(&DefaultSnmp.InCsumErrors, 1)
+				}
+			} else if s.block == nil {
+				dataValid = true
+			}
+
+			if dataValid {
+				s.kcpInput(data)
+			}
+			xmitBuf.Put(raw)
+		case <-s.die:
+			return
+		}
+	}
+}
+
+type (
+	sessionKey struct {
+		addr   string
+		convID uint32
+	}
+
+	// Listener defines a server listening for connections
+	Listener struct {
+		block        BlockCrypt     // block encryption
+		dataShards   int            // FEC data shard
+		parityShards int            // FEC parity shard
+		fecDecoder   *fecDecoder    // FEC mock initialization
+		conn         net.PacketConn // the underlying packet connection
+
+		sessions        map[sessionKey]*UDPSession // all sessions accepted by this Listener
+		chAccepts       chan *UDPSession           // Listen() backlog
+		chSessionClosed chan sessionKey            // session close queue
+		headerSize      int                        // the overall header size added before KCP frame
+		die             chan struct{}              // notify the listener has closed
+		rd              atomic.Value               // read deadline for Accept()
+		wd              atomic.Value
+	}
+
+	// incoming packet
+	inPacket struct {
+		from net.Addr
+		data []byte
+	}
+)
+
+// monitor incoming data for all connections of server
+func (l *Listener) monitor() {
+	// cache last session
+	var lastKey sessionKey
+	var lastSession *UDPSession
+
+	chPacket := make(chan inPacket, qlen)
+	go l.receiver(chPacket)
+	for {
+		select {
+		case p := <-chPacket:
+			raw := p.data
+			data := p.data
+			from := p.from
+			dataValid := false
+			if l.block != nil {
+				l.block.Decrypt(data, data)
+				data = data[nonceSize:]
+				checksum := crc32.ChecksumIEEE(data[crcSize:])
+				if checksum == binary.LittleEndian.Uint32(data) {
+					data = data[crcSize:]
+					dataValid = true
+				} else {
+					atomic.AddUint64(&DefaultSnmp.InCsumErrors, 1)
+				}
+			} else if l.block == nil {
+				dataValid = true
+			}
+
+			if dataValid {
+				var conv uint32
+				convValid := false
+				if l.fecDecoder != nil {
+					isfec := binary.LittleEndian.Uint16(data[4:])
+					if isfec == typeData {
+						conv = binary.LittleEndian.Uint32(data[fecHeaderSizePlus2:])
+						convValid = true
+					}
+				} else {
+					conv = binary.LittleEndian.Uint32(data)
+					convValid = true
+				}
+
+				if convValid {
+					key := sessionKey{
+						addr:   from.String(),
+						convID: conv,
+					}
+					var s *UDPSession
+					var ok bool
+
+					// packets received from an address always come in batch.
+					// cache the session for next packet, without querying map.
+					if key == lastKey {
+						s, ok = lastSession, true
+					} else if s, ok = l.sessions[key]; ok {
+						lastSession = s
+						lastKey = key
+					}
+
+					if !ok { // new session
+						if len(l.chAccepts) < cap(l.chAccepts) && len(l.sessions) < 4096 { // do not let new session overwhelm accept queue and connection count
+							s := newUDPSession(conv, l.dataShards, l.parityShards, l, l.conn, from, l.block)
+							s.kcpInput(data)
+							l.sessions[key] = s
+							l.chAccepts <- s
+						}
+					} else {
+						s.kcpInput(data)
+					}
+				}
+			}
+
+			xmitBuf.Put(raw)
+		case key := <-l.chSessionClosed:
+			if key == lastKey {
+				lastKey = sessionKey{}
+			}
+			delete(l.sessions, key)
+		case <-l.die:
+			return
+		}
+	}
+}
+
+func (l *Listener) receiver(ch chan<- inPacket) {
+	for {
+		data := xmitBuf.Get().([]byte)[:mtuLimit]
+		if n, from, err := l.conn.ReadFrom(data); err == nil && n >= l.headerSize+IKCP_OVERHEAD {
+			select {
+			case ch <- inPacket{from, data[:n]}:
+			case <-l.die:
+				return
+			}
+		} else if err != nil {
+			return
+		} else {
+			atomic.AddUint64(&DefaultSnmp.InErrs, 1)
+		}
+	}
+}
+
+// SetReadBuffer sets the socket read buffer for the Listener
+func (l *Listener) SetReadBuffer(bytes int) error {
+	if nc, ok := l.conn.(setReadBuffer); ok {
+		return nc.SetReadBuffer(bytes)
+	}
+	return errors.New(errInvalidOperation)
+}
+
+// SetWriteBuffer sets the socket write buffer for the Listener
+func (l *Listener) SetWriteBuffer(bytes int) error {
+	if nc, ok := l.conn.(setWriteBuffer); ok {
+		return nc.SetWriteBuffer(bytes)
+	}
+	return errors.New(errInvalidOperation)
+}
+
+// SetDSCP sets the 6bit DSCP field of IP header
+func (l *Listener) SetDSCP(dscp int) error {
+	if nc, ok := l.conn.(net.Conn); ok {
+		return ipv4.NewConn(nc).SetTOS(dscp << 2)
+	}
+	return errors.New(errInvalidOperation)
+}
+
+// Accept implements the Accept method in the Listener interface; it waits for the next call and returns a generic Conn.
+func (l *Listener) Accept() (net.Conn, error) {
+	return l.AcceptKCP()
+}
+
+// AcceptKCP accepts a KCP connection
+func (l *Listener) AcceptKCP() (*UDPSession, error) {
+	var timeout <-chan time.Time
+	if tdeadline, ok := l.rd.Load().(time.Time); ok && !tdeadline.IsZero() {
+		timeout = time.After(tdeadline.Sub(time.Now()))
+	}
+
+	select {
+	case <-timeout:
+		return nil, &errTimeout{}
+	case c := <-l.chAccepts:
+		return c, nil
+	case <-l.die:
+		return nil, errors.New(errBrokenPipe)
+	}
+}
+
+// SetDeadline sets the deadline associated with the listener. A zero time value disables the deadline.
+func (l *Listener) SetDeadline(t time.Time) error {
+	l.SetReadDeadline(t)
+	l.SetWriteDeadline(t)
+	return nil
+}
+
+// SetReadDeadline implements the Conn SetReadDeadline method.
+func (l *Listener) SetReadDeadline(t time.Time) error {
+	l.rd.Store(t)
+	return nil
+}
+
+// SetWriteDeadline implements the Conn SetWriteDeadline method.
+func (l *Listener) SetWriteDeadline(t time.Time) error {
+	l.wd.Store(t)
+	return nil
+}
+
+// Close stops listening on the UDP address. Already Accepted connections are not closed.
+func (l *Listener) Close() error {
+	close(l.die)
+	return l.conn.Close()
+}
+
+// closeSession notify the listener that a session has closed
+func (l *Listener) closeSession(key sessionKey) bool {
+	select {
+	case l.chSessionClosed <- key:
+		return true
+	case <-l.die:
+		return false
+	}
+}
+
+// Addr returns the listener's network address, The Addr returned is shared by all invocations of Addr, so do not modify it.
+func (l *Listener) Addr() net.Addr { return l.conn.LocalAddr() }
+
+// Listen listens for incoming KCP packets addressed to the local address laddr on the network "udp",
+func Listen(laddr string) (net.Listener, error) { return ListenWithOptions(laddr, nil, 0, 0) }
+
+// ListenWithOptions listens for incoming KCP packets addressed to the local address laddr on the network "udp" with packet encryption,
+// dataShards, parityShards defines Reed-Solomon Erasure Coding parameters
+func ListenWithOptions(laddr string, block BlockCrypt, dataShards, parityShards int) (*Listener, error) {
+	udpaddr, err := net.ResolveUDPAddr("udp", laddr)
+	if err != nil {
+		return nil, errors.Wrap(err, "net.ResolveUDPAddr")
+	}
+	conn, err := net.ListenUDP("udp", udpaddr)
+	if err != nil {
+		return nil, errors.Wrap(err, "net.ListenUDP")
+	}
+
+	return ServeConn(block, dataShards, parityShards, conn)
+}
+
+// ServeConn serves KCP protocol for a single packet connection.
+func ServeConn(block BlockCrypt, dataShards, parityShards int, conn net.PacketConn) (*Listener, error) {
+	l := new(Listener)
+	l.conn = conn
+	l.sessions = make(map[sessionKey]*UDPSession)
+	l.chAccepts = make(chan *UDPSession, acceptBacklog)
+	l.chSessionClosed = make(chan sessionKey)
+	l.die = make(chan struct{})
+	l.dataShards = dataShards
+	l.parityShards = parityShards
+	l.block = block
+	l.fecDecoder = newFECDecoder(rxFECMulti*(dataShards+parityShards), dataShards, parityShards)
+
+	// calculate header size
+	if l.block != nil {
+		l.headerSize += cryptHeaderSize
+	}
+	if l.fecDecoder != nil {
+		l.headerSize += fecHeaderSizePlus2
+	}
+
+	go l.monitor()
+	return l, nil
+}
+
+// Dial connects to the remote address "raddr" on the network "udp"
+func Dial(raddr string) (net.Conn, error) { return DialWithOptions(raddr, nil, 0, 0) }
+
+// DialWithOptions connects to the remote address "raddr" on the network "udp" with packet encryption
+func DialWithOptions(raddr string, block BlockCrypt, dataShards, parityShards int) (*UDPSession, error) {
+	udpaddr, err := net.ResolveUDPAddr("udp", raddr)
+	if err != nil {
+		return nil, errors.Wrap(err, "net.ResolveUDPAddr")
+	}
+
+	udpconn, err := net.DialUDP("udp", nil, udpaddr)
+	if err != nil {
+		return nil, errors.Wrap(err, "net.DialUDP")
+	}
+
+	return NewConn(raddr, block, dataShards, parityShards, &connectedUDPConn{udpconn})
+}
+
+// NewConn establishes a session and talks KCP protocol over a packet connection.
+func NewConn(raddr string, block BlockCrypt, dataShards, parityShards int, conn net.PacketConn) (*UDPSession, error) {
+	udpaddr, err := net.ResolveUDPAddr("udp", raddr)
+	if err != nil {
+		return nil, errors.Wrap(err, "net.ResolveUDPAddr")
+	}
+
+	var convid uint32
+	binary.Read(rand.Reader, binary.LittleEndian, &convid)
+	return newUDPSession(convid, dataShards, parityShards, nil, conn, udpaddr, block), nil
+}
+
+// returns current time in milliseconds
+func currentMs() uint32 { return uint32(time.Now().UnixNano() / int64(time.Millisecond)) }
+
+// connectedUDPConn is a wrapper for net.UDPConn which converts WriteTo syscalls
+// to Write syscalls that are 4 times faster on some OS'es. This should only be
+// used for connections that were produced by a net.Dial* call.
+type connectedUDPConn struct{ *net.UDPConn }
+
+// WriteTo redirects all writes to the Write syscall, which is 4 times faster.
+func (c *connectedUDPConn) WriteTo(b []byte, addr net.Addr) (int, error) { return c.Write(b) }

vendor/github.com/xtaci/kcp-go/snmp.go

@@ -0,0 +1,164 @@
+package kcp
+
+import (
+	"fmt"
+	"sync/atomic"
+)
+
+// Snmp defines network statistics indicator
+type Snmp struct {
+	BytesSent        uint64 // bytes sent from upper level
+	BytesReceived    uint64 // bytes received to upper level
+	MaxConn          uint64 // max number of connections ever reached
+	ActiveOpens      uint64 // accumulated active open connections
+	PassiveOpens     uint64 // accumulated passive open connections
+	CurrEstab        uint64 // current number of established connections
+	InErrs           uint64 // UDP read errors reported from net.PacketConn
+	InCsumErrors     uint64 // checksum errors from CRC32
+	KCPInErrors      uint64 // packet iput errors reported from KCP
+	InPkts           uint64 // incoming packets count
+	OutPkts          uint64 // outgoing packets count
+	InSegs           uint64 // incoming KCP segments
+	OutSegs          uint64 // outgoing KCP segments
+	InBytes          uint64 // UDP bytes received
+	OutBytes         uint64 // UDP bytes sent
+	RetransSegs      uint64 // accmulated retransmited segments
+	FastRetransSegs  uint64 // accmulated fast retransmitted segments
+	EarlyRetransSegs uint64 // accmulated early retransmitted segments
+	LostSegs         uint64 // number of segs infered as lost
+	RepeatSegs       uint64 // number of segs duplicated
+	FECRecovered     uint64 // correct packets recovered from FEC
+	FECErrs          uint64 // incorrect packets recovered from FEC
+	FECParityShards  uint64 // FEC segments received
+	FECShortShards   uint64 // number of data shards that's not enough for recovery
+}
+
+func newSnmp() *Snmp {
+	return new(Snmp)
+}
+
+// Header returns all field names
+func (s *Snmp) Header() []string {
+	return []string{
+		"BytesSent",
+		"BytesReceived",
+		"MaxConn",
+		"ActiveOpens",
+		"PassiveOpens",
+		"CurrEstab",
+		"InErrs",
+		"InCsumErrors",
+		"KCPInErrors",
+		"InPkts",
+		"OutPkts",
+		"InSegs",
+		"OutSegs",
+		"InBytes",
+		"OutBytes",
+		"RetransSegs",
+		"FastRetransSegs",
+		"EarlyRetransSegs",
+		"LostSegs",
+		"RepeatSegs",
+		"FECParityShards",
+		"FECErrs",
+		"FECRecovered",
+		"FECShortShards",
+	}
+}
+
+// ToSlice returns current snmp info as slice
+func (s *Snmp) ToSlice() []string {
+	snmp := s.Copy()
+	return []string{
+		fmt.Sprint(snmp.BytesSent),
+		fmt.Sprint(snmp.BytesReceived),
+		fmt.Sprint(snmp.MaxConn),
+		fmt.Sprint(snmp.ActiveOpens),
+		fmt.Sprint(snmp.PassiveOpens),
+		fmt.Sprint(snmp.CurrEstab),
+		fmt.Sprint(snmp.InErrs),
+		fmt.Sprint(snmp.InCsumErrors),
+		fmt.Sprint(snmp.KCPInErrors),
+		fmt.Sprint(snmp.InPkts),
+		fmt.Sprint(snmp.OutPkts),
+		fmt.Sprint(snmp.InSegs),
+		fmt.Sprint(snmp.OutSegs),
+		fmt.Sprint(snmp.InBytes),
+		fmt.Sprint(snmp.OutBytes),
+		fmt.Sprint(snmp.RetransSegs),
+		fmt.Sprint(snmp.FastRetransSegs),
+		fmt.Sprint(snmp.EarlyRetransSegs),
+		fmt.Sprint(snmp.LostSegs),
+		fmt.Sprint(snmp.RepeatSegs),
+		fmt.Sprint(snmp.FECParityShards),
+		fmt.Sprint(snmp.FECErrs),
+		fmt.Sprint(snmp.FECRecovered),
+		fmt.Sprint(snmp.FECShortShards),
+	}
+}
+
+// Copy make a copy of current snmp snapshot
+func (s *Snmp) Copy() *Snmp {
+	d := newSnmp()
+	d.BytesSent = atomic.LoadUint64(&s.BytesSent)
+	d.BytesReceived = atomic.LoadUint64(&s.BytesReceived)
+	d.MaxConn = atomic.LoadUint64(&s.MaxConn)
+	d.ActiveOpens = atomic.LoadUint64(&s.ActiveOpens)
+	d.PassiveOpens = atomic.LoadUint64(&s.PassiveOpens)
+	d.CurrEstab = atomic.LoadUint64(&s.CurrEstab)
+	d.InErrs = atomic.LoadUint64(&s.InErrs)
+	d.InCsumErrors = atomic.LoadUint64(&s.InCsumErrors)
+	d.KCPInErrors = atomic.LoadUint64(&s.KCPInErrors)
+	d.InPkts = atomic.LoadUint64(&s.InPkts)
+	d.OutPkts = atomic.LoadUint64(&s.OutPkts)
+	d.InSegs = atomic.LoadUint64(&s.InSegs)
+	d.OutSegs = atomic.LoadUint64(&s.OutSegs)
+	d.InBytes = atomic.LoadUint64(&s.InBytes)
+	d.OutBytes = atomic.LoadUint64(&s.OutBytes)
+	d.RetransSegs = atomic.LoadUint64(&s.RetransSegs)
+	d.FastRetransSegs = atomic.LoadUint64(&s.FastRetransSegs)
+	d.EarlyRetransSegs = atomic.LoadUint64(&s.EarlyRetransSegs)
+	d.LostSegs = atomic.LoadUint64(&s.LostSegs)
+	d.RepeatSegs = atomic.LoadUint64(&s.RepeatSegs)
+	d.FECParityShards = atomic.LoadUint64(&s.FECParityShards)
+	d.FECErrs = atomic.LoadUint64(&s.FECErrs)
+	d.FECRecovered = atomic.LoadUint64(&s.FECRecovered)
+	d.FECShortShards = atomic.LoadUint64(&s.FECShortShards)
+	return d
+}
+
+// Reset values to zero
+func (s *Snmp) Reset() {
+	atomic.StoreUint64(&s.BytesSent, 0)
+	atomic.StoreUint64(&s.BytesReceived, 0)
+	atomic.StoreUint64(&s.MaxConn, 0)
+	atomic.StoreUint64(&s.ActiveOpens, 0)
+	atomic.StoreUint64(&s.PassiveOpens, 0)
+	atomic.StoreUint64(&s.CurrEstab, 0)
+	atomic.StoreUint64(&s.InErrs, 0)
+	atomic.StoreUint64(&s.InCsumErrors, 0)
+	atomic.StoreUint64(&s.KCPInErrors, 0)
+	atomic.StoreUint64(&s.InPkts, 0)
+	atomic.StoreUint64(&s.OutPkts, 0)
+	atomic.StoreUint64(&s.InSegs, 0)
+	atomic.StoreUint64(&s.OutSegs, 0)
+	atomic.StoreUint64(&s.InBytes, 0)
+	atomic.StoreUint64(&s.OutBytes, 0)
+	atomic.StoreUint64(&s.RetransSegs, 0)
+	atomic.StoreUint64(&s.FastRetransSegs, 0)
+	atomic.StoreUint64(&s.EarlyRetransSegs, 0)
+	atomic.StoreUint64(&s.LostSegs, 0)
+	atomic.StoreUint64(&s.RepeatSegs, 0)
+	atomic.StoreUint64(&s.FECParityShards, 0)
+	atomic.StoreUint64(&s.FECErrs, 0)
+	atomic.StoreUint64(&s.FECRecovered, 0)
+	atomic.StoreUint64(&s.FECShortShards, 0)
+}
+
+// DefaultSnmp is the global KCP connection statistics collector
+var DefaultSnmp *Snmp
+
+func init() {
+	DefaultSnmp = newSnmp()
+}

vendor/github.com/xtaci/kcp-go/updater.go

@@ -0,0 +1,105 @@
+package kcp
+
+import (
+	"container/heap"
+	"sync"
+	"time"
+)
+
+var updater updateHeap
+
+func init() {
+	updater.init()
+	go updater.updateTask()
+}
+
+// entry contains a session update info
+type entry struct {
+	ts time.Time
+	s  *UDPSession
+}
+
+// a global heap managed kcp.flush() caller
+type updateHeap struct {
+	entries  []entry
+	mu       sync.Mutex
+	chWakeUp chan struct{}
+}
+
+func (h *updateHeap) Len() int           { return len(h.entries) }
+func (h *updateHeap) Less(i, j int) bool { return h.entries[i].ts.Before(h.entries[j].ts) }
+func (h *updateHeap) Swap(i, j int) {
+	h.entries[i], h.entries[j] = h.entries[j], h.entries[i]
+	h.entries[i].s.updaterIdx = i
+	h.entries[j].s.updaterIdx = j
+}
+
+func (h *updateHeap) Push(x interface{}) {
+	h.entries = append(h.entries, x.(entry))
+	n := len(h.entries)
+	h.entries[n-1].s.updaterIdx = n - 1
+}
+
+func (h *updateHeap) Pop() interface{} {
+	n := len(h.entries)
+	x := h.entries[n-1]
+	h.entries[n-1].s.updaterIdx = -1
+	h.entries[n-1] = entry{} // manual set nil for GC
+	h.entries = h.entries[0 : n-1]
+	return x
+}
+
+func (h *updateHeap) init() {
+	h.chWakeUp = make(chan struct{}, 1)
+}
+
+func (h *updateHeap) addSession(s *UDPSession) {
+	h.mu.Lock()
+	heap.Push(h, entry{time.Now(), s})
+	h.mu.Unlock()
+	h.wakeup()
+}
+
+func (h *updateHeap) removeSession(s *UDPSession) {
+	h.mu.Lock()
+	if s.updaterIdx != -1 {
+		heap.Remove(h, s.updaterIdx)
+	}
+	h.mu.Unlock()
+}
+
+func (h *updateHeap) wakeup() {
+	select {
+	case h.chWakeUp <- struct{}{}:
+	default:
+	}
+}
+
+func (h *updateHeap) updateTask() {
+	var timer <-chan time.Time
+	for {
+		select {
+		case <-timer:
+		case <-h.chWakeUp:
+		}
+
+		h.mu.Lock()
+		hlen := h.Len()
+		now := time.Now()
+		for i := 0; i < hlen; i++ {
+			entry := heap.Pop(h).(entry)
+			if now.After(entry.ts) {
+				entry.ts = now.Add(entry.s.update())
+				heap.Push(h, entry)
+			} else {
+				heap.Push(h, entry)
+				break
+			}
+		}
+
+		if hlen > 0 {
+			timer = time.After(h.entries[0].ts.Sub(now))
+		}
+		h.mu.Unlock()
+	}
+}

vendor/github.com/xtaci/kcp-go/xor.go

@@ -0,0 +1,110 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package kcp
+
+import (
+	"runtime"
+	"unsafe"
+)
+
+const wordSize = int(unsafe.Sizeof(uintptr(0)))
+const supportsUnaligned = runtime.GOARCH == "386" || runtime.GOARCH == "amd64" || runtime.GOARCH == "ppc64" || runtime.GOARCH == "ppc64le" || runtime.GOARCH == "s390x"
+
+// fastXORBytes xors in bulk. It only works on architectures that
+// support unaligned read/writes.
+func fastXORBytes(dst, a, b []byte) int {
+	n := len(a)
+	if len(b) < n {
+		n = len(b)
+	}
+
+	w := n / wordSize
+	if w > 0 {
+		wordBytes := w * wordSize
+		fastXORWords(dst[:wordBytes], a[:wordBytes], b[:wordBytes])
+	}
+
+	for i := (n - n%wordSize); i < n; i++ {
+		dst[i] = a[i] ^ b[i]
+	}
+
+	return n
+}
+
+func safeXORBytes(dst, a, b []byte) int {
+	n := len(a)
+	if len(b) < n {
+		n = len(b)
+	}
+	ex := n % 8
+	for i := 0; i < ex; i++ {
+		dst[i] = a[i] ^ b[i]
+	}
+
+	for i := ex; i < n; i += 8 {
+		_dst := dst[i : i+8]
+		_a := a[i : i+8]
+		_b := b[i : i+8]
+		_dst[0] = _a[0] ^ _b[0]
+		_dst[1] = _a[1] ^ _b[1]
+		_dst[2] = _a[2] ^ _b[2]
+		_dst[3] = _a[3] ^ _b[3]
+
+		_dst[4] = _a[4] ^ _b[4]
+		_dst[5] = _a[5] ^ _b[5]
+		_dst[6] = _a[6] ^ _b[6]
+		_dst[7] = _a[7] ^ _b[7]
+	}
+	return n
+}
+
+// xorBytes xors the bytes in a and b. The destination is assumed to have enough
+// space. Returns the number of bytes xor'd.
+func xorBytes(dst, a, b []byte) int {
+	if supportsUnaligned {
+		return fastXORBytes(dst, a, b)
+	}
+	// TODO(hanwen): if (dst, a, b) have common alignment
+	// we could still try fastXORBytes. It is not clear
+	// how often this happens, and it's only worth it if
+	// the block encryption itself is hardware
+	// accelerated.
+	return safeXORBytes(dst, a, b)
+}
+
+// fastXORWords XORs multiples of 4 or 8 bytes (depending on architecture.)
+// The arguments are assumed to be of equal length.
+func fastXORWords(dst, a, b []byte) {
+	dw := *(*[]uintptr)(unsafe.Pointer(&dst))
+	aw := *(*[]uintptr)(unsafe.Pointer(&a))
+	bw := *(*[]uintptr)(unsafe.Pointer(&b))
+	n := len(b) / wordSize
+	ex := n % 8
+	for i := 0; i < ex; i++ {
+		dw[i] = aw[i] ^ bw[i]
+	}
+
+	for i := ex; i < n; i += 8 {
+		_dw := dw[i : i+8]
+		_aw := aw[i : i+8]
+		_bw := bw[i : i+8]
+		_dw[0] = _aw[0] ^ _bw[0]
+		_dw[1] = _aw[1] ^ _bw[1]
+		_dw[2] = _aw[2] ^ _bw[2]
+		_dw[3] = _aw[3] ^ _bw[3]
+		_dw[4] = _aw[4] ^ _bw[4]
+		_dw[5] = _aw[5] ^ _bw[5]
+		_dw[6] = _aw[6] ^ _bw[6]
+		_dw[7] = _aw[7] ^ _bw[7]
+	}
+}
+
+func xorWords(dst, a, b []byte) {
+	if supportsUnaligned {
+		fastXORWords(dst, a, b)
+	} else {
+		safeXORBytes(dst, a, b)
+	}
+}

vendor/github.com/xtaci/smux/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2016-2017 Daniel Fu
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/xtaci/smux/README.md

@@ -0,0 +1,99 @@
+<img src="smux.png" alt="smux" height="35px" />
+
+[![GoDoc][1]][2] [![MIT licensed][3]][4] [![Build Status][5]][6] [![Go Report Card][7]][8] [![Coverage Statusd][9]][10]
+
+<img src="mux.jpg" alt="smux" height="120px" /> 
+
+[1]: https://godoc.org/github.com/xtaci/smux?status.svg
+[2]: https://godoc.org/github.com/xtaci/smux
+[3]: https://img.shields.io/badge/license-MIT-blue.svg
+[4]: LICENSE
+[5]: https://travis-ci.org/xtaci/smux.svg?branch=master
+[6]: https://travis-ci.org/xtaci/smux
+[7]: https://goreportcard.com/badge/github.com/xtaci/smux
+[8]: https://goreportcard.com/report/github.com/xtaci/smux
+[9]: https://codecov.io/gh/xtaci/smux/branch/master/graph/badge.svg
+[10]: https://codecov.io/gh/xtaci/smux
+
+## Introduction
+
+Smux ( **S**imple **MU**ltiple**X**ing) is a multiplexing library for Golang. It relies on an underlying connection to provide reliability and ordering, such as TCP or [KCP](https://github.com/xtaci/kcp-go), and provides stream-oriented multiplexing. The original intention of this library is to power the connection management for [kcp-go](https://github.com/xtaci/kcp-go).
+
+## Features
+
+1. Tiny, less than 600 LOC.
+2. ***Token bucket*** controlled receiving, which provides smoother bandwidth graph(see picture below).
+3. Session-wide receive buffer, shared among streams, tightly controlled overall memory usage.
+4. Minimized header(8Bytes), maximized payload. 
+5. Well-tested on millions of devices in [kcptun](https://github.com/xtaci/kcptun).
+
+![smooth bandwidth curve](curve.jpg)
+
+## Documentation
+
+For complete documentation, see the associated [Godoc](https://godoc.org/github.com/xtaci/smux).
+
+## Specification
+
+```
+VERSION(1B) | CMD(1B) | LENGTH(2B) | STREAMID(4B) | DATA(LENGTH)  
+```
+
+## Usage
+
+The API of smux are mostly taken from [yamux](https://github.com/hashicorp/yamux)
+
+```go
+
+func client() {
+    // Get a TCP connection
+    conn, err := net.Dial(...)
+    if err != nil {
+        panic(err)
+    }
+
+    // Setup client side of smux
+    session, err := smux.Client(conn, nil)
+    if err != nil {
+        panic(err)
+    }
+
+    // Open a new stream
+    stream, err := session.OpenStream()
+    if err != nil {
+        panic(err)
+    }
+
+    // Stream implements io.ReadWriteCloser
+    stream.Write([]byte("ping"))
+}
+
+func server() {
+    // Accept a TCP connection
+    conn, err := listener.Accept()
+    if err != nil {
+        panic(err)
+    }
+
+    // Setup server side of smux
+    session, err := smux.Server(conn, nil)
+    if err != nil {
+        panic(err)
+    }
+
+    // Accept a stream
+    stream, err := session.AcceptStream()
+    if err != nil {
+        panic(err)
+    }
+
+    // Listen for a message
+    buf := make([]byte, 4)
+    stream.Read(buf)
+}
+
+```
+
+## Status
+
+Stable

vendor/github.com/xtaci/smux/frame.go

@@ -0,0 +1,60 @@
+package smux
+
+import (
+	"encoding/binary"
+	"fmt"
+)
+
+const (
+	version = 1
+)
+
+const ( // cmds
+	cmdSYN byte = iota // stream open
+	cmdFIN             // stream close, a.k.a EOF mark
+	cmdPSH             // data push
+	cmdNOP             // no operation
+)
+
+const (
+	sizeOfVer    = 1
+	sizeOfCmd    = 1
+	sizeOfLength = 2
+	sizeOfSid    = 4
+	headerSize   = sizeOfVer + sizeOfCmd + sizeOfSid + sizeOfLength
+)
+
+// Frame defines a packet from or to be multiplexed into a single connection
+type Frame struct {
+	ver  byte
+	cmd  byte
+	sid  uint32
+	data []byte
+}
+
+func newFrame(cmd byte, sid uint32) Frame {
+	return Frame{ver: version, cmd: cmd, sid: sid}
+}
+
+type rawHeader []byte
+
+func (h rawHeader) Version() byte {
+	return h[0]
+}
+
+func (h rawHeader) Cmd() byte {
+	return h[1]
+}
+
+func (h rawHeader) Length() uint16 {
+	return binary.LittleEndian.Uint16(h[2:])
+}
+
+func (h rawHeader) StreamID() uint32 {
+	return binary.LittleEndian.Uint32(h[4:])
+}
+
+func (h rawHeader) String() string {
+	return fmt.Sprintf("Version:%d Cmd:%d StreamID:%d Length:%d",
+		h.Version(), h.Cmd(), h.StreamID(), h.Length())
+}

vendor/github.com/xtaci/smux/mux.go

@@ -0,0 +1,80 @@
+package smux
+
+import (
+	"fmt"
+	"io"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+// Config is used to tune the Smux session
+type Config struct {
+	// KeepAliveInterval is how often to send a NOP command to the remote
+	KeepAliveInterval time.Duration
+
+	// KeepAliveTimeout is how long the session
+	// will be closed if no data has arrived
+	KeepAliveTimeout time.Duration
+
+	// MaxFrameSize is used to control the maximum
+	// frame size to sent to the remote
+	MaxFrameSize int
+
+	// MaxReceiveBuffer is used to control the maximum
+	// number of data in the buffer pool
+	MaxReceiveBuffer int
+}
+
+// DefaultConfig is used to return a default configuration
+func DefaultConfig() *Config {
+	return &Config{
+		KeepAliveInterval: 10 * time.Second,
+		KeepAliveTimeout:  30 * time.Second,
+		MaxFrameSize:      4096,
+		MaxReceiveBuffer:  4194304,
+	}
+}
+
+// VerifyConfig is used to verify the sanity of configuration
+func VerifyConfig(config *Config) error {
+	if config.KeepAliveInterval == 0 {
+		return errors.New("keep-alive interval must be positive")
+	}
+	if config.KeepAliveTimeout < config.KeepAliveInterval {
+		return fmt.Errorf("keep-alive timeout must be larger than keep-alive interval")
+	}
+	if config.MaxFrameSize <= 0 {
+		return errors.New("max frame size must be positive")
+	}
+	if config.MaxFrameSize > 65535 {
+		return errors.New("max frame size must not be larger than 65535")
+	}
+	if config.MaxReceiveBuffer <= 0 {
+		return errors.New("max receive buffer must be positive")
+	}
+	return nil
+}
+
+// Server is used to initialize a new server-side connection.
+func Server(conn io.ReadWriteCloser, config *Config) (*Session, error) {
+	if config == nil {
+		config = DefaultConfig()
+	}
+	if err := VerifyConfig(config); err != nil {
+		return nil, err
+	}
+	return newSession(config, conn, false), nil
+}
+
+// Client is used to initialize a new client-side connection.
+func Client(conn io.ReadWriteCloser, config *Config) (*Session, error) {
+	if config == nil {
+		config = DefaultConfig()
+	}
+
+	if err := VerifyConfig(config); err != nil {
+		return nil, err
+	}
+	return newSession(config, conn, true), nil
+}

vendor/github.com/xtaci/smux/session.go

@@ -0,0 +1,353 @@
+package smux
+
+import (
+	"encoding/binary"
+	"io"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+const (
+	defaultAcceptBacklog = 1024
+)
+
+const (
+	errBrokenPipe      = "broken pipe"
+	errInvalidProtocol = "invalid protocol version"
+	errGoAway          = "stream id overflows, should start a new connection"
+)
+
+type writeRequest struct {
+	frame  Frame
+	result chan writeResult
+}
+
+type writeResult struct {
+	n   int
+	err error
+}
+
+// Session defines a multiplexed connection for streams
+type Session struct {
+	conn io.ReadWriteCloser
+
+	config           *Config
+	nextStreamID     uint32 // next stream identifier
+	nextStreamIDLock sync.Mutex
+
+	bucket       int32         // token bucket
+	bucketNotify chan struct{} // used for waiting for tokens
+
+	streams    map[uint32]*Stream // all streams in this session
+	streamLock sync.Mutex         // locks streams
+
+	die       chan struct{} // flag session has died
+	dieLock   sync.Mutex
+	chAccepts chan *Stream
+
+	dataReady int32 // flag data has arrived
+
+	goAway int32 // flag id exhausted
+
+	deadline atomic.Value
+
+	writes chan writeRequest
+}
+
+func newSession(config *Config, conn io.ReadWriteCloser, client bool) *Session {
+	s := new(Session)
+	s.die = make(chan struct{})
+	s.conn = conn
+	s.config = config
+	s.streams = make(map[uint32]*Stream)
+	s.chAccepts = make(chan *Stream, defaultAcceptBacklog)
+	s.bucket = int32(config.MaxReceiveBuffer)
+	s.bucketNotify = make(chan struct{}, 1)
+	s.writes = make(chan writeRequest)
+
+	if client {
+		s.nextStreamID = 1
+	} else {
+		s.nextStreamID = 0
+	}
+	go s.recvLoop()
+	go s.sendLoop()
+	go s.keepalive()
+	return s
+}
+
+// OpenStream is used to create a new stream
+func (s *Session) OpenStream() (*Stream, error) {
+	if s.IsClosed() {
+		return nil, errors.New(errBrokenPipe)
+	}
+
+	// generate stream id
+	s.nextStreamIDLock.Lock()
+	if s.goAway > 0 {
+		s.nextStreamIDLock.Unlock()
+		return nil, errors.New(errGoAway)
+	}
+
+	s.nextStreamID += 2
+	sid := s.nextStreamID
+	if sid == sid%2 { // stream-id overflows
+		s.goAway = 1
+		s.nextStreamIDLock.Unlock()
+		return nil, errors.New(errGoAway)
+	}
+	s.nextStreamIDLock.Unlock()
+
+	stream := newStream(sid, s.config.MaxFrameSize, s)
+
+	if _, err := s.writeFrame(newFrame(cmdSYN, sid)); err != nil {
+		return nil, errors.Wrap(err, "writeFrame")
+	}
+
+	s.streamLock.Lock()
+	s.streams[sid] = stream
+	s.streamLock.Unlock()
+	return stream, nil
+}
+
+// AcceptStream is used to block until the next available stream
+// is ready to be accepted.
+func (s *Session) AcceptStream() (*Stream, error) {
+	var deadline <-chan time.Time
+	if d, ok := s.deadline.Load().(time.Time); ok && !d.IsZero() {
+		timer := time.NewTimer(d.Sub(time.Now()))
+		defer timer.Stop()
+		deadline = timer.C
+	}
+	select {
+	case stream := <-s.chAccepts:
+		return stream, nil
+	case <-deadline:
+		return nil, errTimeout
+	case <-s.die:
+		return nil, errors.New(errBrokenPipe)
+	}
+}
+
+// Close is used to close the session and all streams.
+func (s *Session) Close() (err error) {
+	s.dieLock.Lock()
+
+	select {
+	case <-s.die:
+		s.dieLock.Unlock()
+		return errors.New(errBrokenPipe)
+	default:
+		close(s.die)
+		s.dieLock.Unlock()
+		s.streamLock.Lock()
+		for k := range s.streams {
+			s.streams[k].sessionClose()
+		}
+		s.streamLock.Unlock()
+		s.notifyBucket()
+		return s.conn.Close()
+	}
+}
+
+// notifyBucket notifies recvLoop that bucket is available
+func (s *Session) notifyBucket() {
+	select {
+	case s.bucketNotify <- struct{}{}:
+	default:
+	}
+}
+
+// IsClosed does a safe check to see if we have shutdown
+func (s *Session) IsClosed() bool {
+	select {
+	case <-s.die:
+		return true
+	default:
+		return false
+	}
+}
+
+// NumStreams returns the number of currently open streams
+func (s *Session) NumStreams() int {
+	if s.IsClosed() {
+		return 0
+	}
+	s.streamLock.Lock()
+	defer s.streamLock.Unlock()
+	return len(s.streams)
+}
+
+// SetDeadline sets a deadline used by Accept* calls.
+// A zero time value disables the deadline.
+func (s *Session) SetDeadline(t time.Time) error {
+	s.deadline.Store(t)
+	return nil
+}
+
+// notify the session that a stream has closed
+func (s *Session) streamClosed(sid uint32) {
+	s.streamLock.Lock()
+	if n := s.streams[sid].recycleTokens(); n > 0 { // return remaining tokens to the bucket
+		if atomic.AddInt32(&s.bucket, int32(n)) > 0 {
+			s.notifyBucket()
+		}
+	}
+	delete(s.streams, sid)
+	s.streamLock.Unlock()
+}
+
+// returnTokens is called by stream to return token after read
+func (s *Session) returnTokens(n int) {
+	if atomic.AddInt32(&s.bucket, int32(n)) > 0 {
+		s.notifyBucket()
+	}
+}
+
+// session read a frame from underlying connection
+// it's data is pointed to the input buffer
+func (s *Session) readFrame(buffer []byte) (f Frame, err error) {
+	if _, err := io.ReadFull(s.conn, buffer[:headerSize]); err != nil {
+		return f, errors.Wrap(err, "readFrame")
+	}
+
+	dec := rawHeader(buffer)
+	if dec.Version() != version {
+		return f, errors.New(errInvalidProtocol)
+	}
+
+	f.ver = dec.Version()
+	f.cmd = dec.Cmd()
+	f.sid = dec.StreamID()
+	if length := dec.Length(); length > 0 {
+		if _, err := io.ReadFull(s.conn, buffer[headerSize:headerSize+length]); err != nil {
+			return f, errors.Wrap(err, "readFrame")
+		}
+		f.data = buffer[headerSize : headerSize+length]
+	}
+	return f, nil
+}
+
+// recvLoop keeps on reading from underlying connection if tokens are available
+func (s *Session) recvLoop() {
+	buffer := make([]byte, (1<<16)+headerSize)
+	for {
+		for atomic.LoadInt32(&s.bucket) <= 0 && !s.IsClosed() {
+			<-s.bucketNotify
+		}
+
+		if f, err := s.readFrame(buffer); err == nil {
+			atomic.StoreInt32(&s.dataReady, 1)
+
+			switch f.cmd {
+			case cmdNOP:
+			case cmdSYN:
+				s.streamLock.Lock()
+				if _, ok := s.streams[f.sid]; !ok {
+					stream := newStream(f.sid, s.config.MaxFrameSize, s)
+					s.streams[f.sid] = stream
+					select {
+					case s.chAccepts <- stream:
+					case <-s.die:
+					}
+				}
+				s.streamLock.Unlock()
+			case cmdFIN:
+				s.streamLock.Lock()
+				if stream, ok := s.streams[f.sid]; ok {
+					stream.markRST()
+					stream.notifyReadEvent()
+				}
+				s.streamLock.Unlock()
+			case cmdPSH:
+				s.streamLock.Lock()
+				if stream, ok := s.streams[f.sid]; ok {
+					atomic.AddInt32(&s.bucket, -int32(len(f.data)))
+					stream.pushBytes(f.data)
+					stream.notifyReadEvent()
+				}
+				s.streamLock.Unlock()
+			default:
+				s.Close()
+				return
+			}
+		} else {
+			s.Close()
+			return
+		}
+	}
+}
+
+func (s *Session) keepalive() {
+	tickerPing := time.NewTicker(s.config.KeepAliveInterval)
+	tickerTimeout := time.NewTicker(s.config.KeepAliveTimeout)
+	defer tickerPing.Stop()
+	defer tickerTimeout.Stop()
+	for {
+		select {
+		case <-tickerPing.C:
+			s.writeFrame(newFrame(cmdNOP, 0))
+			s.notifyBucket() // force a signal to the recvLoop
+		case <-tickerTimeout.C:
+			if !atomic.CompareAndSwapInt32(&s.dataReady, 1, 0) {
+				s.Close()
+				return
+			}
+		case <-s.die:
+			return
+		}
+	}
+}
+
+func (s *Session) sendLoop() {
+	buf := make([]byte, (1<<16)+headerSize)
+	for {
+		select {
+		case <-s.die:
+			return
+		case request, ok := <-s.writes:
+			if !ok {
+				continue
+			}
+			buf[0] = request.frame.ver
+			buf[1] = request.frame.cmd
+			binary.LittleEndian.PutUint16(buf[2:], uint16(len(request.frame.data)))
+			binary.LittleEndian.PutUint32(buf[4:], request.frame.sid)
+			copy(buf[headerSize:], request.frame.data)
+			n, err := s.conn.Write(buf[:headerSize+len(request.frame.data)])
+
+			n -= headerSize
+			if n < 0 {
+				n = 0
+			}
+
+			result := writeResult{
+				n:   n,
+				err: err,
+			}
+
+			request.result <- result
+			close(request.result)
+		}
+	}
+}
+
+// writeFrame writes the frame to the underlying connection
+// and returns the number of bytes written if successful
+func (s *Session) writeFrame(f Frame) (n int, err error) {
+	req := writeRequest{
+		frame:  f,
+		result: make(chan writeResult, 1),
+	}
+	select {
+	case <-s.die:
+		return 0, errors.New(errBrokenPipe)
+	case s.writes <- req:
+	}
+
+	result := <-req.result
+	return result.n, result.err
+}

vendor/github.com/xtaci/smux/stream.go

@@ -0,0 +1,253 @@
+package smux
+
+import (
+	"bytes"
+	"io"
+	"net"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+// Stream implements net.Conn
+type Stream struct {
+	id            uint32
+	rstflag       int32
+	sess          *Session
+	buffer        bytes.Buffer
+	bufferLock    sync.Mutex
+	frameSize     int
+	chReadEvent   chan struct{} // notify a read event
+	die           chan struct{} // flag the stream has closed
+	dieLock       sync.Mutex
+	readDeadline  atomic.Value
+	writeDeadline atomic.Value
+}
+
+// newStream initiates a Stream struct
+func newStream(id uint32, frameSize int, sess *Session) *Stream {
+	s := new(Stream)
+	s.id = id
+	s.chReadEvent = make(chan struct{}, 1)
+	s.frameSize = frameSize
+	s.sess = sess
+	s.die = make(chan struct{})
+	return s
+}
+
+// ID returns the unique stream ID.
+func (s *Stream) ID() uint32 {
+	return s.id
+}
+
+// Read implements net.Conn
+func (s *Stream) Read(b []byte) (n int, err error) {
+	var deadline <-chan time.Time
+	if d, ok := s.readDeadline.Load().(time.Time); ok && !d.IsZero() {
+		timer := time.NewTimer(d.Sub(time.Now()))
+		defer timer.Stop()
+		deadline = timer.C
+	}
+
+READ:
+	s.bufferLock.Lock()
+	n, err = s.buffer.Read(b)
+	s.bufferLock.Unlock()
+
+	if n > 0 {
+		s.sess.returnTokens(n)
+		return n, nil
+	} else if atomic.LoadInt32(&s.rstflag) == 1 {
+		_ = s.Close()
+		return 0, io.EOF
+	}
+
+	select {
+	case <-s.chReadEvent:
+		goto READ
+	case <-deadline:
+		return n, errTimeout
+	case <-s.die:
+		return 0, errors.New(errBrokenPipe)
+	}
+}
+
+// Write implements net.Conn
+func (s *Stream) Write(b []byte) (n int, err error) {
+	var deadline <-chan time.Time
+	if d, ok := s.writeDeadline.Load().(time.Time); ok && !d.IsZero() {
+		timer := time.NewTimer(d.Sub(time.Now()))
+		defer timer.Stop()
+		deadline = timer.C
+	}
+
+	select {
+	case <-s.die:
+		return 0, errors.New(errBrokenPipe)
+	default:
+	}
+
+	frames := s.split(b, cmdPSH, s.id)
+	sent := 0
+	for k := range frames {
+		req := writeRequest{
+			frame:  frames[k],
+			result: make(chan writeResult, 1),
+		}
+
+		select {
+		case s.sess.writes <- req:
+		case <-s.die:
+			return sent, errors.New(errBrokenPipe)
+		case <-deadline:
+			return sent, errTimeout
+		}
+
+		select {
+		case result := <-req.result:
+			sent += result.n
+			if result.err != nil {
+				return sent, result.err
+			}
+		case <-s.die:
+			return sent, errors.New(errBrokenPipe)
+		case <-deadline:
+			return sent, errTimeout
+		}
+	}
+	return sent, nil
+}
+
+// Close implements net.Conn
+func (s *Stream) Close() error {
+	s.dieLock.Lock()
+
+	select {
+	case <-s.die:
+		s.dieLock.Unlock()
+		return errors.New(errBrokenPipe)
+	default:
+		close(s.die)
+		s.dieLock.Unlock()
+		s.sess.streamClosed(s.id)
+		_, err := s.sess.writeFrame(newFrame(cmdFIN, s.id))
+		return err
+	}
+}
+
+// SetReadDeadline sets the read deadline as defined by
+// net.Conn.SetReadDeadline.
+// A zero time value disables the deadline.
+func (s *Stream) SetReadDeadline(t time.Time) error {
+	s.readDeadline.Store(t)
+	return nil
+}
+
+// SetWriteDeadline sets the write deadline as defined by
+// net.Conn.SetWriteDeadline.
+// A zero time value disables the deadline.
+func (s *Stream) SetWriteDeadline(t time.Time) error {
+	s.writeDeadline.Store(t)
+	return nil
+}
+
+// SetDeadline sets both read and write deadlines as defined by
+// net.Conn.SetDeadline.
+// A zero time value disables the deadlines.
+func (s *Stream) SetDeadline(t time.Time) error {
+	if err := s.SetReadDeadline(t); err != nil {
+		return err
+	}
+	if err := s.SetWriteDeadline(t); err != nil {
+		return err
+	}
+	return nil
+}
+
+// session closes the stream
+func (s *Stream) sessionClose() {
+	s.dieLock.Lock()
+	defer s.dieLock.Unlock()
+
+	select {
+	case <-s.die:
+	default:
+		close(s.die)
+	}
+}
+
+// LocalAddr satisfies net.Conn interface
+func (s *Stream) LocalAddr() net.Addr {
+	if ts, ok := s.sess.conn.(interface {
+		LocalAddr() net.Addr
+	}); ok {
+		return ts.LocalAddr()
+	}
+	return nil
+}
+
+// RemoteAddr satisfies net.Conn interface
+func (s *Stream) RemoteAddr() net.Addr {
+	if ts, ok := s.sess.conn.(interface {
+		RemoteAddr() net.Addr
+	}); ok {
+		return ts.RemoteAddr()
+	}
+	return nil
+}
+
+// pushBytes a slice into buffer
+func (s *Stream) pushBytes(p []byte) {
+	s.bufferLock.Lock()
+	s.buffer.Write(p)
+	s.bufferLock.Unlock()
+}
+
+// recycleTokens transform remaining bytes to tokens(will truncate buffer)
+func (s *Stream) recycleTokens() (n int) {
+	s.bufferLock.Lock()
+	n = s.buffer.Len()
+	s.buffer.Reset()
+	s.bufferLock.Unlock()
+	return
+}
+
+// split large byte buffer into smaller frames, reference only
+func (s *Stream) split(bts []byte, cmd byte, sid uint32) []Frame {
+	frames := make([]Frame, 0, len(bts)/s.frameSize+1)
+	for len(bts) > s.frameSize {
+		frame := newFrame(cmd, sid)
+		frame.data = bts[:s.frameSize]
+		bts = bts[s.frameSize:]
+		frames = append(frames, frame)
+	}
+	if len(bts) > 0 {
+		frame := newFrame(cmd, sid)
+		frame.data = bts
+		frames = append(frames, frame)
+	}
+	return frames
+}
+
+// notify read event
+func (s *Stream) notifyReadEvent() {
+	select {
+	case s.chReadEvent <- struct{}{}:
+	default:
+	}
+}
+
+// mark this stream has been reset
+func (s *Stream) markRST() {
+	atomic.StoreInt32(&s.rstflag, 1)
+}
+
+var errTimeout error = &timeoutError{}
+
+type timeoutError struct{}
+
+func (e *timeoutError) Error() string   { return "i/o timeout" }
+func (e *timeoutError) Timeout() bool   { return true }
+func (e *timeoutError) Temporary() bool { return true }

vendor/golang.org/x/crypto/AUTHORS

@@ -0,0 +1,3 @@
+# This source code refers to The Go Authors for copyright purposes.
+# The master list of authors is in the main Go distribution,
+# visible at http://tip.golang.org/AUTHORS.