Reuse buffer for constructing request.

connpool.go

@@ -10,14 +10,16 @@ import (
 )
 
 type Conn struct {
-	RW io.ReadWriteCloser
-	Rd *bufio.Reader
+	RW     io.ReadWriteCloser
+	Rd     *bufio.Reader
+	ReqBuf []byte
 }
 
 func NewConn(rw io.ReadWriteCloser) *Conn {
 	return &Conn{
-		RW: rw,
-		Rd: bufio.NewReaderSize(rw, 1024),
+		RW:     rw,
+		Rd:     bufio.NewReaderSize(rw, 1024),
+		ReqBuf: make([]byte, 0, 1024),
 	}
 }
 

multi.go

@@ -35,21 +35,20 @@ func (c *MultiClient) Unwatch(keys ...string) *StatusReq {
 
 func (c *MultiClient) Discard() {
 	c.mtx.Lock()
-	c.reqs = c.reqs[:0]
+	c.reqs = []Req{NewStatusReq("MULTI")}
 	c.mtx.Unlock()
 }
 
 func (c *MultiClient) Exec(do func()) ([]Req, error) {
-	c.mtx.Lock()
-	c.reqs = make([]Req, 0)
-	c.mtx.Unlock()
+	c.Discard()
 
 	do()
 
 	c.mtx.Lock()
-	if len(c.reqs) == 0 {
+	c.reqs = append(c.reqs, NewMultiBulkReq("EXEC"))
+	if len(c.reqs) == 2 {
 		c.mtx.Unlock()
-		return c.reqs, nil
+		return []Req{}, nil
 	}
 	reqs := c.reqs
 	c.reqs = nil
@@ -67,18 +66,11 @@ func (c *MultiClient) Exec(do func()) ([]Req, error) {
 	}
 
 	c.ConnPool.Add(conn)
-	return reqs, nil
+	return reqs[1 : len(reqs)-1], nil
 }
 
 func (c *MultiClient) ExecReqs(reqs []Req, conn *Conn) error {
-	multiReq := make([]byte, 0, 1024)
-	multiReq = append(multiReq, PackReq([]string{"MULTI"})...)
-	for _, req := range reqs {
-		multiReq = append(multiReq, req.Req()...)
-	}
-	multiReq = append(multiReq, PackReq([]string{"EXEC"})...)
-
-	err := c.WriteReq(multiReq, conn)
+	err := c.WriteReq(conn, reqs...)
 	if err != nil {
 		return err
 	}
@@ -92,7 +84,7 @@ func (c *MultiClient) ExecReqs(reqs []Req, conn *Conn) error {
 	}
 
 	// Parse queued replies.
-	for _ = range reqs {
+	for i := 1; i < len(reqs)-1; i++ {
 		_, err = statusReq.ParseReply(conn.Rd)
 		if err != nil {
 			return err
@@ -112,7 +104,7 @@ func (c *MultiClient) ExecReqs(reqs []Req, conn *Conn) error {
 	}
 
 	// Parse replies.
-	for i := 0; i < len(reqs); i++ {
+	for i := 1; i < len(reqs)-1; i++ {
 		req := reqs[i]
 		val, err := req.ParseReply(conn.Rd)
 		if err != nil {

parser.go

@@ -21,8 +21,7 @@ var (
 
 //------------------------------------------------------------------------------
 
-func PackReq(args []string) []byte {
-	buf := make([]byte, 0, 1024)
+func AppendReq(buf []byte, args []string) []byte {
 	buf = append(buf, '*')
 	buf = strconv.AppendUint(buf, uint64(len(args)), 10)
 	buf = append(buf, '\r', '\n')

pipeline.go

@@ -46,17 +46,7 @@ func (c *PipelineClient) RunQueued() ([]Req, error) {
 }
 
 func (c *PipelineClient) RunReqs(reqs []Req, conn *Conn) error {
-	var multiReq []byte
-	if len(reqs) == 1 {
-		multiReq = reqs[0].Req()
-	} else {
-		multiReq = make([]byte, 0, 1024)
-		for _, req := range reqs {
-			multiReq = append(multiReq, req.Req()...)
-		}
-	}
-
-	err := c.WriteReq(multiReq, conn)
+	err := c.WriteReq(conn, reqs...)
 	if err != nil {
 		return err
 	}

pubsub.go

@@ -89,7 +89,7 @@ func (c *PubSubClient) subscribe(cmd string, channels ...string) (chan *Message,
 		return nil, err
 	}
 
-	if err := c.WriteReq(req.Req(), conn); err != nil {
+	if err := c.WriteReq(conn, req); err != nil {
 		return nil, err
 	}
 
@@ -117,7 +117,7 @@ func (c *PubSubClient) unsubscribe(cmd string, channels ...string) error {
 		return err
 	}
 
-	return c.WriteReq(req.Req(), conn)
+	return c.WriteReq(conn, req)
 }
 
 func (c *PubSubClient) Unsubscribe(channels ...string) error {

redis.go

@@ -56,8 +56,13 @@ type BaseClient struct {
 	reqs     []Req
 }
 
-func (c *BaseClient) WriteReq(buf []byte, conn *Conn) error {
-	_, err := conn.RW.Write(buf)
+func (c *BaseClient) WriteReq(conn *Conn, reqs ...Req) error {
+	conn.ReqBuf = conn.ReqBuf[:0]
+	for _, req := range reqs {
+		conn.ReqBuf = AppendReq(conn.ReqBuf, req.Args())
+	}
+
+	_, err := conn.RW.Write(conn.ReqBuf)
 	return err
 }
 
@@ -96,7 +101,7 @@ func (c *BaseClient) Run(req Req) {
 		return
 	}
 
-	err = c.WriteReq(req.Req(), conn)
+	err = c.WriteReq(conn, req)
 	if err != nil {
 		c.ConnPool.Remove(conn)
 		req.SetErr(err)

redis_test.go

@@ -2412,7 +2412,7 @@ func (t *RedisTest) BenchmarkRedisWriteRead(c *C) {
 	c.Assert(err, IsNil)
 
 	for i := 0; i < 10; i++ {
-		err := t.client.WriteReq([]byte("PING\r\n"), conn)
+		err := t.client.WriteReq(conn, redis.NewStatusReq("PING"))
 		c.Assert(err, IsNil)
 
 		line, _, err := conn.Rd.ReadLine()
@@ -2423,7 +2423,7 @@ func (t *RedisTest) BenchmarkRedisWriteRead(c *C) {
 	c.StartTimer()
 
 	for i := 0; i < c.N; i++ {
-		t.client.WriteReq([]byte("PING\r\n"), conn)
+		t.client.WriteReq(conn, redis.NewStatusReq("PING"))
 		conn.Rd.ReadLine()
 	}
 

request.go

@@ -5,7 +5,7 @@ import (
 )
 
 type Req interface {
-	Req() []byte
+	Args() []string
 	ParseReply(ReadLiner) (interface{}, error)
 	SetErr(error)
 	Err() error
@@ -28,8 +28,8 @@ func NewBaseReq(args ...string) *BaseReq {
 	}
 }
 
-func (r *BaseReq) Req() []byte {
-	return PackReq(r.args)
+func (r *BaseReq) Args() []string {
+	return r.args
 }
 
 func (r *BaseReq) SetErr(err error) {