allocate buffer on stack

common/buf/buffer.go

@@ -199,3 +199,11 @@ func New() *Buffer {
 		v: pool.Get().([]byte),
 	}
 }
+
+// StackNew creates a new Buffer object on stack.
+// This method is for buffers that is released in the same function.
+func StackNew() Buffer {
+	return Buffer{
+		v: pool.Get().([]byte),
+	}
+}

proxy/socks/protocol.go

@@ -190,7 +190,7 @@ func (s *ServerSession) Handshake(reader io.Reader, writer io.Writer) (*protocol
 // | 1  |  1   | 1 to 255 |  1   | 1 to 255 |
 // +----+------+----------+------+----------+
 func ReadUsernamePassword(reader io.Reader) (string, string, error) {
-	buffer := buf.New()
+	buffer := buf.StackNew()
 	defer buffer.Release()
 
 	if _, err := buffer.ReadFullFrom(reader, 2); err != nil {
@@ -220,7 +220,7 @@ func ReadUsernamePassword(reader io.Reader) (string, string, error) {
 
 // ReadUntilNull reads content from given reader, until a null (0x00) byte.
 func ReadUntilNull(reader io.Reader) (string, error) {
-	b := buf.New()
+	b := buf.StackNew()
 	defer b.Release()
 
 	for {

proxy/socks/protocol_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"testing"
 
+	"v2ray.com/core/common"
 	"v2ray.com/core/common/buf"
 	"v2ray.com/core/common/net"
 	_ "v2ray.com/core/common/net/testing"
@@ -107,3 +108,17 @@ func TestReadUntilNull(t *testing.T) {
 		}
 	}
 }
+
+func BenchmarkReadUsernamePassword(b *testing.B) {
+	input := []byte{0x05, 0x01, 'a', 0x02, 'b', 'c'}
+	buffer := buf.New()
+	buffer.Write(input)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, _, err := ReadUsernamePassword(buffer)
+		common.Must(err)
+		buffer.Clear()
+		buffer.Extend(int32(len(input)))
+	}
+}

proxy/vmess/encoding/client.go

@@ -164,7 +164,7 @@ func (c *ClientSession) DecodeResponseHeader(reader io.Reader) (*protocol.Respon
 	aesStream := crypto.NewAesDecryptionStream(c.responseBodyKey[:], c.responseBodyIV[:])
 	c.responseReader = crypto.NewCryptionReader(aesStream, reader)
 
-	buffer := buf.New()
+	buffer := buf.StackNew()
 	defer buffer.Release()
 
 	if _, err := buffer.ReadFullFrom(c.responseReader, 4); err != nil {

transport/internet/kcp/io.go

@@ -70,7 +70,7 @@ func (w *KCPPacketWriter) Overhead() int {
 }
 
 func (w *KCPPacketWriter) Write(b []byte) (int, error) {
-	bb := buf.New()
+	bb := buf.StackNew()
 	defer bb.Release()
 
 	if w.Header != nil {