Fix ReceiveMessage to work without any subscriptions.

Makefile

@@ -15,4 +15,5 @@ testdata/redis:
 	wget -qO- https://github.com/antirez/redis/archive/unstable.tar.gz | tar xvz --strip-components=1 -C $@
 
 testdata/redis/src/redis-server: testdata/redis
+	sed -i 's/libjemalloc.a/libjemalloc.a -lrt/g' $</src/Makefile
 	cd $< && make all

command.go

@@ -58,7 +58,7 @@ func writeCmd(cn *pool.Conn, cmds ...Cmder) error {
 		}
 	}
 
-	_, err := cn.NetConn.Write(cn.Wb.Bytes())
+	_, err := cn.Write(cn.Wb.Bytes())
 	return err
 }
 

internal/pool/conn.go

@@ -2,56 +2,78 @@ package pool
 
 import (
 	"net"
+	"sync/atomic"
 	"time"
 
 	"gopkg.in/redis.v5/internal/proto"
 )
 
-const defaultBufSize = 4096
-
 var noDeadline = time.Time{}
 
 type Conn struct {
-	NetConn net.Conn
-	Rd      *proto.Reader
-	Wb      *proto.WriteBuffer
+	netConn net.Conn
+
+	Rd *proto.Reader
+	Wb *proto.WriteBuffer
 
 	Inited bool
-	UsedAt time.Time
+	usedAt atomic.Value
 }
 
 func NewConn(netConn net.Conn) *Conn {
+	buf := make([]byte, 4096)
 	cn := &Conn{
-		NetConn: netConn,
-		Wb:      proto.NewWriteBuffer(),
-
-		UsedAt: time.Now(),
+		netConn: netConn,
+		Wb:      proto.NewWriteBuffer(buf),
 	}
-	cn.Rd = proto.NewReader(cn.NetConn)
+	cn.Rd = proto.NewReader(cn.netConn, buf)
+	cn.SetUsedAt(time.Now())
 	return cn
 }
 
+func (cn *Conn) UsedAt() time.Time {
+	return cn.usedAt.Load().(time.Time)
+}
+
+func (cn *Conn) SetUsedAt(tm time.Time) {
+	cn.usedAt.Store(tm)
+}
+
+func (cn *Conn) SetNetConn(netConn net.Conn) {
+	cn.netConn = netConn
+	cn.Rd.Reset(netConn)
+}
+
 func (cn *Conn) IsStale(timeout time.Duration) bool {
-	return timeout > 0 && time.Since(cn.UsedAt) > timeout
+	return timeout > 0 && time.Since(cn.UsedAt()) > timeout
 }
 
 func (cn *Conn) SetReadTimeout(timeout time.Duration) error {
-	cn.UsedAt = time.Now()
+	now := time.Now()
+	cn.SetUsedAt(now)
 	if timeout > 0 {
-		return cn.NetConn.SetReadDeadline(cn.UsedAt.Add(timeout))
+		return cn.netConn.SetReadDeadline(now.Add(timeout))
 	}
-	return cn.NetConn.SetReadDeadline(noDeadline)
-
+	return cn.netConn.SetReadDeadline(noDeadline)
 }
 
 func (cn *Conn) SetWriteTimeout(timeout time.Duration) error {
-	cn.UsedAt = time.Now()
+	now := time.Now()
+	cn.SetUsedAt(now)
 	if timeout > 0 {
-		return cn.NetConn.SetWriteDeadline(cn.UsedAt.Add(timeout))
+		return cn.netConn.SetWriteDeadline(now.Add(timeout))
 	}
-	return cn.NetConn.SetWriteDeadline(noDeadline)
+	return cn.netConn.SetWriteDeadline(noDeadline)
+}
+
+func (cn *Conn) Write(b []byte) (int, error) {
+	return cn.netConn.Write(b)
+}
+
+func (cn *Conn) RemoteAddr() net.Addr {
+	return cn.netConn.RemoteAddr()
 }
 
 func (cn *Conn) Close() error {
-	return cn.NetConn.Close()
+	return cn.netConn.Close()
 }

internal/pool/pool.go

@@ -41,7 +41,6 @@ type Pooler interface {
 	FreeLen() int
 	Stats() *Stats
 	Close() error
-	Closed() bool
 }
 
 type dialer func() (net.Conn, error)
@@ -132,7 +131,7 @@ func (p *ConnPool) popFree() *Conn {
 
 // Get returns existed connection from the pool or creates a new one.
 func (p *ConnPool) Get() (*Conn, bool, error) {
-	if p.Closed() {
+	if p.closed() {
 		return nil, false, ErrClosed
 	}
 
@@ -241,7 +240,7 @@ func (p *ConnPool) Stats() *Stats {
 	}
 }
 
-func (p *ConnPool) Closed() bool {
+func (p *ConnPool) closed() bool {
 	return atomic.LoadInt32(&p._closed) == 1
 }
 
@@ -318,7 +317,7 @@ func (p *ConnPool) reaper(frequency time.Duration) {
 	defer ticker.Stop()
 
 	for _ = range ticker.C {
-		if p.Closed() {
+		if p.closed() {
 			break
 		}
 		n, err := p.ReapStaleConns()

internal/pool/pool_single.go

@@ -12,10 +12,6 @@ func NewSingleConnPool(cn *Conn) *SingleConnPool {
 	}
 }
 
-func (p *SingleConnPool) First() *Conn {
-	return p.cn
-}
-
 func (p *SingleConnPool) Get() (*Conn, bool, error) {
 	return p.cn, false, nil
 }
@@ -49,7 +45,3 @@ func (p *SingleConnPool) Stats() *Stats {
 func (p *SingleConnPool) Close() error {
 	return nil
 }
-
-func (p *SingleConnPool) Closed() bool {
-	return false
-}

internal/pool/pool_sticky.go

@@ -23,13 +23,6 @@ func NewStickyConnPool(pool *ConnPool, reusable bool) *StickyConnPool {
 	}
 }
 
-func (p *StickyConnPool) First() *Conn {
-	p.mu.Lock()
-	cn := p.cn
-	p.mu.Unlock()
-	return cn
-}
-
 func (p *StickyConnPool) Get() (*Conn, bool, error) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
@@ -62,9 +55,6 @@ func (p *StickyConnPool) Put(cn *Conn) error {
 	if p.closed {
 		return ErrClosed
 	}
-	if p.cn != cn {
-		panic("p.cn != cn")
-	}
 	return nil
 }
 
@@ -81,12 +71,6 @@ func (p *StickyConnPool) Remove(cn *Conn, reason error) error {
 	if p.closed {
 		return nil
 	}
-	if p.cn == nil {
-		panic("p.cn == nil")
-	}
-	if cn != nil && p.cn != cn {
-		panic("p.cn != cn")
-	}
 	return p.removeUpstream(reason)
 }
 
@@ -133,10 +117,3 @@ func (p *StickyConnPool) Close() error {
 	}
 	return err
 }
-
-func (p *StickyConnPool) Closed() bool {
-	p.mu.Lock()
-	closed := p.closed
-	p.mu.Unlock()
-	return closed
-}

internal/pool/pool_test.go

@@ -100,7 +100,7 @@ var _ = Describe("conns reaper", func() {
 		for i := 0; i < 3; i++ {
 			cn, _, err := connPool.Get()
 			Expect(err).NotTo(HaveOccurred())
-			cn.UsedAt = time.Now().Add(-2 * idleTimeout)
+			cn.SetUsedAt(time.Now().Add(-2 * idleTimeout))
 			conns = append(conns, cn)
 			idleConns = append(idleConns, cn)
 		}

internal/proto/reader.go

@@ -26,13 +26,17 @@ type Reader struct {
 	buf []byte
 }
 
-func NewReader(rd io.Reader) *Reader {
+func NewReader(rd io.Reader, buf []byte) *Reader {
 	return &Reader{
 		src: bufio.NewReader(rd),
-		buf: make([]byte, 0, bufferSize),
+		buf: buf,
 	}
 }
 
+func (r *Reader) Reset(rd io.Reader) {
+	r.src.Reset(rd)
+}
+
 func (p *Reader) PeekBuffered() []byte {
 	if n := p.src.Buffered(); n != 0 {
 		b, _ := p.src.Peek(n)
@@ -42,7 +46,12 @@ func (p *Reader) PeekBuffered() []byte {
 }
 
 func (p *Reader) ReadN(n int) ([]byte, error) {
-	return readN(p.src, p.buf, n)
+	b, err := readN(p.src, p.buf, n)
+	if err != nil {
+		return nil, err
+	}
+	p.buf = b
+	return b, nil
 }
 
 func (p *Reader) ReadLine() ([]byte, error) {
@@ -72,11 +81,11 @@ func (p *Reader) ReadReply(m MultiBulkParse) (interface{}, error) {
 	case ErrorReply:
 		return nil, ParseErrorReply(line)
 	case StatusReply:
-		return parseStatusValue(line)
+		return parseStatusValue(line), nil
 	case IntReply:
 		return parseInt(line[1:], 10, 64)
 	case StringReply:
-		return p.readBytesValue(line)
+		return p.readTmpBytesValue(line)
 	case ArrayReply:
 		n, err := parseArrayLen(line)
 		if err != nil {
@@ -111,9 +120,9 @@ func (p *Reader) ReadTmpBytesReply() ([]byte, error) {
 	case ErrorReply:
 		return nil, ParseErrorReply(line)
 	case StringReply:
-		return p.readBytesValue(line)
+		return p.readTmpBytesValue(line)
 	case StatusReply:
-		return parseStatusValue(line)
+		return parseStatusValue(line), nil
 	default:
 		return nil, fmt.Errorf("redis: can't parse string reply: %.100q", line)
 	}
@@ -210,7 +219,7 @@ func (p *Reader) ReadScanReply() ([]string, uint64, error) {
 	return keys, cursor, err
 }
 
-func (p *Reader) readBytesValue(line []byte) ([]byte, error) {
+func (p *Reader) readTmpBytesValue(line []byte) ([]byte, error) {
 	if isNilReply(line) {
 		return nil, internal.Nil
 	}
@@ -297,8 +306,8 @@ func ParseErrorReply(line []byte) error {
 	return internal.RedisError(string(line[1:]))
 }
 
-func parseStatusValue(line []byte) ([]byte, error) {
-	return line[1:], nil
+func parseStatusValue(line []byte) []byte {
+	return line[1:]
 }
 
 func parseArrayLen(line []byte) (int64, error) {

internal/proto/reader_test.go

@@ -5,27 +5,27 @@ import (
 	"strings"
 	"testing"
 
+	"gopkg.in/redis.v5/internal/proto"
+
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
-
-	"gopkg.in/redis.v5/internal/proto"
 )
 
 var _ = Describe("Reader", func() {
 
 	It("should read n bytes", func() {
-		data, err := proto.NewReader(strings.NewReader("ABCDEFGHIJKLMNO")).ReadN(10)
+		data, err := proto.NewReader(strings.NewReader("ABCDEFGHIJKLMNO"), nil).ReadN(10)
 		Expect(err).NotTo(HaveOccurred())
 		Expect(len(data)).To(Equal(10))
 		Expect(string(data)).To(Equal("ABCDEFGHIJ"))
 
-		data, err = proto.NewReader(strings.NewReader(strings.Repeat("x", 8192))).ReadN(6000)
+		data, err = proto.NewReader(strings.NewReader(strings.Repeat("x", 8192)), nil).ReadN(6000)
 		Expect(err).NotTo(HaveOccurred())
 		Expect(len(data)).To(Equal(6000))
 	})
 
 	It("should read lines", func() {
-		p := proto.NewReader(strings.NewReader("$5\r\nhello\r\n"))
+		p := proto.NewReader(strings.NewReader("$5\r\nhello\r\n"), nil)
 
 		data, err := p.ReadLine()
 		Expect(err).NotTo(HaveOccurred())
@@ -59,11 +59,11 @@ func BenchmarkReader_ParseReply_Slice(b *testing.B) {
 }
 
 func benchmarkParseReply(b *testing.B, reply string, m proto.MultiBulkParse, wanterr bool) {
-	buf := &bytes.Buffer{}
+	buf := new(bytes.Buffer)
 	for i := 0; i < b.N; i++ {
 		buf.WriteString(reply)
 	}
-	p := proto.NewReader(buf)
+	p := proto.NewReader(buf, nil)
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {

internal/proto/writebuffer.go → internal/proto/write_buffer.go

@@ -8,11 +8,13 @@ import (
 
 const bufferSize = 4096
 
-type WriteBuffer struct{ b []byte }
+type WriteBuffer struct {
+	b []byte
+}
 
-func NewWriteBuffer() *WriteBuffer {
+func NewWriteBuffer(b []byte) *WriteBuffer {
 	return &WriteBuffer{
-		b: make([]byte, 0, bufferSize),
+		b: b,
 	}
 }
 

internal/proto/writebuffer_test.go → internal/proto/write_buffer_test.go

@@ -4,17 +4,17 @@ import (
 	"testing"
 	"time"
 
+	"gopkg.in/redis.v5/internal/proto"
+
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
-
-	"gopkg.in/redis.v5/internal/proto"
 )
 
 var _ = Describe("WriteBuffer", func() {
 	var buf *proto.WriteBuffer
 
 	BeforeEach(func() {
-		buf = proto.NewWriteBuffer()
+		buf = proto.NewWriteBuffer(nil)
 	})
 
 	It("should reset", func() {
@@ -53,7 +53,7 @@ var _ = Describe("WriteBuffer", func() {
 })
 
 func BenchmarkWriteBuffer_Append(b *testing.B) {
-	buf := proto.NewWriteBuffer()
+	buf := proto.NewWriteBuffer(nil)
 	args := []interface{}{"hello", "world", "foo", "bar"}
 
 	for i := 0; i < b.N; i++ {