新增go modules支持，自行管理第三方包依赖，方便开发者使用

third/github.com/gomodule/redigo/redis/pubsub_example_test.go

@@ -0,0 +1,165 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+// +build go1.7
+
+package redis_test
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"gitee.com/johng/gf/third/github.com/gomodule/redigo/redis"
+)
+
+// listenPubSubChannels listens for messages on Redis pubsub channels. The
+// onStart function is called after the channels are subscribed. The onMessage
+// function is called for each message.
+func listenPubSubChannels(ctx context.Context, redisServerAddr string,
+	onStart func() error,
+	onMessage func(channel string, data []byte) error,
+	channels ...string) error {
+	// A ping is set to the server with this period to test for the health of
+	// the connection and server.
+	const healthCheckPeriod = time.Minute
+
+	c, err := redis.Dial("tcp", redisServerAddr,
+		// Read timeout on server should be greater than ping period.
+		redis.DialReadTimeout(healthCheckPeriod+10*time.Second),
+		redis.DialWriteTimeout(10*time.Second))
+	if err != nil {
+		return err
+	}
+	defer c.Close()
+
+	psc := redis.PubSubConn{Conn: c}
+
+	if err := psc.Subscribe(redis.Args{}.AddFlat(channels)...); err != nil {
+		return err
+	}
+
+	done := make(chan error, 1)
+
+	// Start a goroutine to receive notifications from the server.
+	go func() {
+		for {
+			switch n := psc.Receive().(type) {
+			case error:
+				done <- n
+				return
+			case redis.Message:
+				if err := onMessage(n.Channel, n.Data); err != nil {
+					done <- err
+					return
+				}
+			case redis.Subscription:
+				switch n.Count {
+				case len(channels):
+					// Notify application when all channels are subscribed.
+					if err := onStart(); err != nil {
+						done <- err
+						return
+					}
+				case 0:
+					// Return from the goroutine when all channels are unsubscribed.
+					done <- nil
+					return
+				}
+			}
+		}
+	}()
+
+	ticker := time.NewTicker(healthCheckPeriod)
+	defer ticker.Stop()
+loop:
+	for err == nil {
+		select {
+		case <-ticker.C:
+			// Send ping to test health of connection and server. If
+			// corresponding pong is not received, then receive on the
+			// connection will timeout and the receive goroutine will exit.
+			if err = psc.Ping(""); err != nil {
+				break loop
+			}
+		case <-ctx.Done():
+			break loop
+		case err := <-done:
+			// Return error from the receive goroutine.
+			return err
+		}
+	}
+
+	// Signal the receiving goroutine to exit by unsubscribing from all channels.
+	psc.Unsubscribe()
+
+	// Wait for goroutine to complete.
+	return <-done
+}
+
+func publish() {
+	c, err := dial()
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	defer c.Close()
+
+	c.Do("PUBLISH", "c1", "hello")
+	c.Do("PUBLISH", "c2", "world")
+	c.Do("PUBLISH", "c1", "goodbye")
+}
+
+// This example shows how receive pubsub notifications with cancelation and
+// health checks.
+func ExamplePubSubConn() {
+	redisServerAddr, err := serverAddr()
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+
+	err = listenPubSubChannels(ctx,
+		redisServerAddr,
+		func() error {
+			// The start callback is a good place to backfill missed
+			// notifications. For the purpose of this example, a goroutine is
+			// started to send notifications.
+			go publish()
+			return nil
+		},
+		func(channel string, message []byte) error {
+			fmt.Printf("channel: %s, message: %s\n", channel, message)
+
+			// For the purpose of this example, cancel the listener's context
+			// after receiving last message sent by publish().
+			if string(message) == "goodbye" {
+				cancel()
+			}
+			return nil
+		},
+		"c1", "c2")
+
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	// Output:
+	// channel: c1, message: hello
+	// channel: c2, message: world
+	// channel: c1, message: goodbye
+}