proxy: optimize Copy for network connection

go.mod

@@ -11,9 +11,9 @@ require (
 	github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
 	github.com/xtaci/kcp-go/v5 v5.6.1
 	golang.org/x/crypto v0.0.0-20201016220609-9e8e0b390897
-	golang.org/x/net v0.0.0-20201022231255-08b38378de70 // indirect
+	golang.org/x/net v0.0.0-20201024042810-be3efd7ff127 // indirect
 	golang.org/x/sys v0.0.0-20201022201747-fb209a7c41cd // indirect
-	golang.org/x/tools v0.0.0-20201022215848-ffe8bce740af // indirect
+	golang.org/x/tools v0.0.0-20201023174141-c8cfbd0f21e6 // indirect
 	gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b // indirect
 )
 

go.sum

@@ -141,8 +141,8 @@ golang.org/x/net v0.0.0-20200707034311-ab3426394381 h1:VXak5I6aEWmAXeQjA+QSZzlgN
 golang.org/x/net v0.0.0-20200707034311-ab3426394381/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/net v0.0.0-20201021035429-f5854403a974 h1:IX6qOQeG5uLjB/hjjwjedwfjND0hgjPMMyO1RoIXQNI=
 golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
-golang.org/x/net v0.0.0-20201022231255-08b38378de70 h1:Z6x4N9mAi4oF0TbHweCsH618MO6OI6UFgV0FP5n0wBY=
+golang.org/x/net v0.0.0-20201024042810-be3efd7ff127 h1:pZPp9+iYUqwYKLjht0SDBbRCRK/9gAXDy7pz5fRDpjo=
-golang.org/x/net v0.0.0-20201022231255-08b38378de70/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
+golang.org/x/net v0.0.0-20201024042810-be3efd7ff127/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -178,8 +178,8 @@ golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtn
 golang.org/x/tools v0.0.0-20200425043458-8463f397d07c h1:iHhCR0b26amDCiiO+kBguKZom9aMF+NrFxh9zeKR/XU=
 golang.org/x/tools v0.0.0-20200425043458-8463f397d07c/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
 golang.org/x/tools v0.0.0-20200808161706-5bf02b21f123/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
-golang.org/x/tools v0.0.0-20201022215848-ffe8bce740af h1:L1EV/2WjPBRxjdgDu0bbZ5gWPuQ6yX9HjG6hSb2dFV4=
+golang.org/x/tools v0.0.0-20201023174141-c8cfbd0f21e6 h1:rbvTkL9AkFts1cgI78+gG6Yu1pwaqX6hjSJAatB78E4=
-golang.org/x/tools v0.0.0-20201022215848-ffe8bce740af/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
+golang.org/x/tools v0.0.0-20201023174141-c8cfbd0f21e6/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=

proxy/conn.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"net"
 	"os"
+	"runtime"
 	"sync"
 	"time"
 
@@ -70,18 +71,20 @@ func Relay(left, right net.Conn) error {
 	return nil
 }
 
-func worthReadFrom(src io.Reader) bool {
+func worthTry(src io.Reader) bool {
 	switch v := src.(type) {
 	case *net.TCPConn, *net.UnixConn:
 		return true
+	case *io.LimitedReader:
+		return worthTry(v.R)
+	case *Conn:
+		return worthTry(v.Conn)
 	case *os.File:
 		fi, err := v.Stat()
 		if err != nil {
 			return false
 		}
 		return fi.Mode().IsRegular()
-	case *io.LimitedReader:
-		return worthReadFrom(v.R)
 	default:
 		return false
 	}
@@ -95,16 +98,19 @@ func underlyingWriter(c io.Writer) io.Writer {
 }
 
 // Copy copies from src to dst.
-// it will try to avoid memory allocating by using WriteTo or ReadFrom method,
-// if both failed, then it'll fallback to call CopyBuffer method.
 func Copy(dst io.Writer, src io.Reader) (written int64, err error) {
+	dst = underlyingWriter(dst)
+	switch runtime.GOOS {
+	case "linux", "windows", "dragonfly", "freebsd", "solaris":
+		if _, ok := dst.(*net.TCPConn); ok && worthTry(src) {
 			if wt, ok := src.(io.WriterTo); ok {
 				return wt.WriteTo(dst)
 			}
-	dst = underlyingWriter(dst)
+			if rt, ok := dst.(io.ReaderFrom); ok {
-	if rt, ok := dst.(io.ReaderFrom); ok && worthReadFrom(src) {
 				return rt.ReadFrom(src)
 			}
+		}
+	}
 	return CopyBuffer(dst, src)
 }
 

proxy/ws/frame.go

@@ -66,27 +66,27 @@ func (w *frameWriter) Write(b []byte) (int, error) {
 		hdr[1] = maskBit
 	}
 
-	nPayload, nLenField := len(b), 0
+	nPayload, nHeader := len(b), 2
 	switch {
 	case nPayload <= 125:
 		hdr[1] |= byte(nPayload)
 	case nPayload < 65536:
 		hdr[1] |= 126
-		nLenField = 2
+		nHeader += 2
-		binary.BigEndian.PutUint16(hdr[2:2+nLenField], uint16(nPayload))
+		binary.BigEndian.PutUint16(hdr[2:nHeader], uint16(nPayload))
 	default:
 		hdr[1] |= 127
-		nLenField = 8
+		nHeader += 8
-		binary.BigEndian.PutUint64(hdr[2:2+nLenField], uint64(nPayload))
+		binary.BigEndian.PutUint64(hdr[2:nHeader], uint64(nPayload))
 	}
 
-	header := hdr[:2+nLenField]
+	header := hdr[:nHeader]
 	if w.server {
 		n, err := (&net.Buffers{header, b}).WriteTo(w.Writer)
-		if int(n) <= len(header) {
+		if int(n) > nHeader {
-			return 0, err
+			return int(n) - nHeader, err
 		}
-		return int(n) - len(header), err
+		return 0, err
 	}
 
 	payload := pool.GetBuffer(nPayload)
@@ -98,8 +98,8 @@ func (w *frameWriter) Write(b []byte) (int, error) {
 	}
 
 	n, err := (&net.Buffers{header, w.maskKey[:], payload}).WriteTo(w.Writer)
-	if int(n) > len(header)+4 {
+	if int(n) > nHeader+4 {
-		return int(n) - len(header) - 4, err
+		return int(n) - nHeader - 4, err
 	}
 	return 0, err
 }