Simplify resubscribing in PubSub.

cluster.go

@@ -516,7 +516,7 @@ func (c *ClusterClient) pipelineExec(cmds []Cmder) error {
 				}
 			}
 
-			cn, err := node.Client.conn()
+			cn, _, err := node.Client.conn()
 			if err != nil {
 				setCmdsErr(cmds, err)
 				setRetErr(err)

internal/pool/bench_test.go

@@ -16,7 +16,7 @@ func benchmarkPoolGetPut(b *testing.B, poolSize int) {
 
 	b.RunParallel(func(pb *testing.PB) {
 		for pb.Next() {
-			cn, err := connPool.Get()
+			cn, _, err := connPool.Get()
 			if err != nil {
 				b.Fatal(err)
 			}
@@ -48,7 +48,7 @@ func benchmarkPoolGetRemove(b *testing.B, poolSize int) {
 
 	b.RunParallel(func(pb *testing.PB) {
 		for pb.Next() {
-			cn, err := connPool.Get()
+			cn, _, err := connPool.Get()
 			if err != nil {
 				b.Fatal(err)
 			}

internal/pool/pool.go

@@ -36,7 +36,7 @@ type PoolStats struct {
 }
 
 type Pooler interface {
-	Get() (*Conn, error)
+	Get() (*Conn, bool, error)
 	Put(*Conn) error
 	Remove(*Conn, error) error
 	Len() int
@@ -152,9 +152,9 @@ func (p *ConnPool) popFree() *Conn {
 }
 
 // Get returns existed connection from the pool or creates a new one.
-func (p *ConnPool) Get() (*Conn, error) {
+func (p *ConnPool) Get() (*Conn, bool, error) {
 	if p.Closed() {
-		return nil, ErrClosed
+		return nil, false, ErrClosed
 	}
 
 	atomic.AddUint32(&p.stats.Requests, 1)
@@ -170,7 +170,7 @@ func (p *ConnPool) Get() (*Conn, error) {
 	case <-timer.C:
 		timers.Put(timer)
 		atomic.AddUint32(&p.stats.Timeouts, 1)
-		return nil, ErrPoolTimeout
+		return nil, false, ErrPoolTimeout
 	}
 
 	p.freeConnsMu.Lock()
@@ -180,15 +180,15 @@ func (p *ConnPool) Get() (*Conn, error) {
 	if cn != nil {
 		atomic.AddUint32(&p.stats.Hits, 1)
 		if !cn.IsStale(p.idleTimeout) {
-			return cn, nil
+			return cn, false, nil
 		}
 		_ = p.closeConn(cn, errConnStale)
 	}
 
 	newcn, err := p.NewConn()
 	if err != nil {
 		<-p.queue
-		return nil, err
+		return nil, false, err
 	}
 
 	p.connsMu.Lock()
@@ -198,7 +198,7 @@ func (p *ConnPool) Get() (*Conn, error) {
 	p.conns = append(p.conns, newcn)
 	p.connsMu.Unlock()
 
-	return newcn, nil
+	return newcn, true, nil
 }
 
 func (p *ConnPool) Put(cn *Conn) error {

internal/pool/pool_single.go

@@ -16,8 +16,8 @@ func (p *SingleConnPool) First() *Conn {
 	return p.cn
 }
 
-func (p *SingleConnPool) Get() (*Conn, error) {
-	return p.cn, nil
+func (p *SingleConnPool) Get() (*Conn, bool, error) {
+	return p.cn, false, nil
 }
 
 func (p *SingleConnPool) Put(cn *Conn) error {

internal/pool/pool_sticky.go

@@ -30,23 +30,23 @@ func (p *StickyConnPool) First() *Conn {
 	return cn
 }
 
-func (p *StickyConnPool) Get() (*Conn, error) {
+func (p *StickyConnPool) Get() (*Conn, bool, error) {
 	defer p.mx.Unlock()
 	p.mx.Lock()
 
 	if p.closed {
-		return nil, ErrClosed
+		return nil, false, ErrClosed
 	}
 	if p.cn != nil {
-		return p.cn, nil
+		return p.cn, false, nil
 	}
 
-	cn, err := p.pool.Get()
+	cn, _, err := p.pool.Get()
 	if err != nil {
-		return nil, err
+		return nil, false, err
 	}
 	p.cn = cn
-	return cn, nil
+	return cn, true, nil
 }
 
 func (p *StickyConnPool) put() (err error) {

internal/pool/pool_test.go

@@ -26,7 +26,7 @@ var _ = Describe("ConnPool", func() {
 	It("rate limits dial", func() {
 		var rateErr error
 		for i := 0; i < 1000; i++ {
-			cn, err := connPool.Get()
+			cn, _, err := connPool.Get()
 			if err != nil {
 				rateErr = err
 				break
@@ -40,13 +40,13 @@ var _ = Describe("ConnPool", func() {
 
 	It("should unblock client when conn is removed", func() {
 		// Reserve one connection.
-		cn, err := connPool.Get()
+		cn, _, err := connPool.Get()
 		Expect(err).NotTo(HaveOccurred())
 
 		// Reserve all other connections.
 		var cns []*pool.Conn
 		for i := 0; i < 9; i++ {
-			cn, err := connPool.Get()
+			cn, _, err := connPool.Get()
 			Expect(err).NotTo(HaveOccurred())
 			cns = append(cns, cn)
 		}
@@ -57,7 +57,7 @@ var _ = Describe("ConnPool", func() {
 			defer GinkgoRecover()
 
 			started <- true
-			_, err := connPool.Get()
+			_, _, err := connPool.Get()
 			Expect(err).NotTo(HaveOccurred())
 			done <- true
 
@@ -113,7 +113,7 @@ var _ = Describe("conns reaper", func() {
 		// add stale connections
 		idleConns = nil
 		for i := 0; i < 3; i++ {
-			cn, err := connPool.Get()
+			cn, _, err := connPool.Get()
 			Expect(err).NotTo(HaveOccurred())
 			cn.UsedAt = time.Now().Add(-2 * idleTimeout)
 			conns = append(conns, cn)
@@ -122,7 +122,7 @@ var _ = Describe("conns reaper", func() {
 
 		// add fresh connections
 		for i := 0; i < 3; i++ {
-			cn, err := connPool.Get()
+			cn, _, err := connPool.Get()
 			Expect(err).NotTo(HaveOccurred())
 			conns = append(conns, cn)
 		}
@@ -167,7 +167,7 @@ var _ = Describe("conns reaper", func() {
 		for j := 0; j < 3; j++ {
 			var freeCns []*pool.Conn
 			for i := 0; i < 3; i++ {
-				cn, err := connPool.Get()
+				cn, _, err := connPool.Get()
 				Expect(err).NotTo(HaveOccurred())
 				Expect(cn).NotTo(BeNil())
 				freeCns = append(freeCns, cn)
@@ -176,7 +176,7 @@ var _ = Describe("conns reaper", func() {
 			Expect(connPool.Len()).To(Equal(3))
 			Expect(connPool.FreeLen()).To(Equal(0))
 
-			cn, err := connPool.Get()
+			cn, _, err := connPool.Get()
 			Expect(err).NotTo(HaveOccurred())
 			Expect(cn).NotTo(BeNil())
 			conns = append(conns, cn)
@@ -224,15 +224,15 @@ var _ = Describe("race", func() {
 
 		perform(C, func(id int) {
 			for i := 0; i < N; i++ {
-				cn, err := connPool.Get()
+				cn, _, err := connPool.Get()
 				Expect(err).NotTo(HaveOccurred())
 				if err == nil {
 					Expect(connPool.Put(cn)).NotTo(HaveOccurred())
 				}
 			}
 		}, func(id int) {
 			for i := 0; i < N; i++ {
-				cn, err := connPool.Get()
+				cn, _, err := connPool.Get()
 				Expect(err).NotTo(HaveOccurred())
 				if err == nil {
 					Expect(connPool.Remove(cn, errors.New("test"))).NotTo(HaveOccurred())
@@ -248,7 +248,7 @@ var _ = Describe("race", func() {
 
 		perform(C, func(id int) {
 			for i := 0; i < N; i++ {
-				cn, err := connPool.Get()
+				cn, _, err := connPool.Get()
 				Expect(err).NotTo(HaveOccurred())
 				if err == nil {
 					Expect(connPool.Put(cn)).NotTo(HaveOccurred())

pool_test.go

@@ -91,7 +91,7 @@ var _ = Describe("pool", func() {
 	})
 
 	It("should remove broken connections", func() {
-		cn, err := client.Pool().Get()
+		cn, _, err := client.Pool().Get()
 		Expect(err).NotTo(HaveOccurred())
 		cn.NetConn = &badConn{}
 		Expect(client.Pool().Put(cn)).NotTo(HaveOccurred())

pubsub.go

@@ -18,12 +18,25 @@ type PubSub struct {
 
 	channels []string
 	patterns []string
+}
+
+func (c *PubSub) conn() (*pool.Conn, bool, error) {
+	cn, isNew, err := c.base.conn()
+	if err != nil {
+		return nil, false, err
+	}
+	if isNew {
+		c.resubscribe()
+	}
+	return cn, isNew, nil
+}
 
-	nsub int // number of active subscriptions
+func (c *PubSub) putConn(cn *pool.Conn, err error) {
+	c.base.putConn(cn, err, true)
 }
 
 func (c *PubSub) subscribe(redisCmd string, channels ...string) error {
-	cn, err := c.base.conn()
+	cn, _, err := c.conn()
 	if err != nil {
 		return err
 	}
@@ -44,7 +57,6 @@ func (c *PubSub) Subscribe(channels ...string) error {
 	err := c.subscribe("SUBSCRIBE", channels...)
 	if err == nil {
 		c.channels = appendIfNotExists(c.channels, channels...)
-		c.nsub += len(channels)
 	}
 	return err
 }
@@ -54,43 +66,10 @@ func (c *PubSub) PSubscribe(patterns ...string) error {
 	err := c.subscribe("PSUBSCRIBE", patterns...)
 	if err == nil {
 		c.patterns = appendIfNotExists(c.patterns, patterns...)
-		c.nsub += len(patterns)
 	}
 	return err
 }
 
-func remove(ss []string, es ...string) []string {
-	if len(es) == 0 {
-		return ss[:0]
-	}
-	for _, e := range es {
-		for i, s := range ss {
-			if s == e {
-				ss = append(ss[:i], ss[i+1:]...)
-				break
-			}
-		}
-	}
-	return ss
-}
-
-func appendIfNotExists(ss []string, es ...string) []string { 
-	for _, e := range es {
-		found := false
-		for _, s := range ss {
-			if s == e {
-				found = true
-				break
-			}
-		}	
-
-		if !found {
-			ss = append(ss, e)
-		}
-	}
-	return ss
-}
-
 // Unsubscribes the client from the given channels, or from all of
 // them if none is given.
 func (c *PubSub) Unsubscribe(channels ...string) error {
@@ -116,7 +95,7 @@ func (c *PubSub) Close() error {
 }
 
 func (c *PubSub) Ping(payload string) error {
-	cn, err := c.base.conn()
+	cn, _, err := c.conn()
 	if err != nil {
 		return err
 	}
@@ -198,11 +177,7 @@ func (c *PubSub) newMessage(reply []interface{}) (interface{}, error) {
 // is not received in time. This is low-level API and most clients
 // should use ReceiveMessage.
 func (c *PubSub) ReceiveTimeout(timeout time.Duration) (interface{}, error) {
-	if c.nsub == 0 {
-		c.resubscribe()
-	}
-
-	cn, err := c.base.conn()
+	cn, _, err := c.conn()
 	if err != nil {
 		return nil, err
 	}
@@ -274,12 +249,6 @@ func (c *PubSub) receiveMessage(timeout time.Duration) (*Message, error) {
 	}
 }
 
-func (c *PubSub) putConn(cn *pool.Conn, err error) {
-	if !c.base.putConn(cn, err, true) {
-		c.nsub = 0
-	}
-}
-
 func (c *PubSub) resubscribe() {
 	if c.base.closed() {
 		return
@@ -295,3 +264,31 @@ func (c *PubSub) resubscribe() {
 		}
 	}
 }
+
+func remove(ss []string, es ...string) []string {
+	if len(es) == 0 {
+		return ss[:0]
+	}
+	for _, e := range es {
+		for i, s := range ss {
+			if s == e {
+				ss = append(ss[:i], ss[i+1:]...)
+				break
+			}
+		}
+	}
+	return ss
+}
+
+func appendIfNotExists(ss []string, es ...string) []string {
+loop:
+	for _, e := range es {
+		for _, s := range ss {
+			if s == e {
+				continue loop
+			}
+		}
+		ss = append(ss, e)
+	}
+	return ss
+}

pubsub_test.go

@@ -288,7 +288,7 @@ var _ = Describe("PubSub", func() {
 	})
 
 	expectReceiveMessageOnError := func(pubsub *redis.PubSub) {
-		cn1, err := pubsub.Pool().Get()
+		cn1, _, err := pubsub.Pool().Get()
 		Expect(err).NotTo(HaveOccurred())
 		cn1.NetConn = &badConn{
 			readErr:  io.EOF,