Redigo 示例

redis在golang中采用来做缓存，下面提供golang操作redis实例。

示例

• Redis 常用命令
• bsm/redislock 使用 Redis 实现的分布式锁

基础使用

package main

import (
	"log"
	"time"

	"github.com/gomodule/redigo/redis"
)

func main() {

	conn, err := redis.Dial("tcp", "100.80.0.128:6379", redis.DialPassword("foobared"))
	if err != nil {
		log.Fatal(err)
	}
	defer conn.Close()

	keys, _ := redis.Strings(conn.Do("keys", "*"))
	log.Println(keys)

	//conn.Do("set", "abc:starttime", time.Now().Format("2006-01-02 15:04:05"), "NX")
	conn.Do("set", "abc:starttime", time.Now().Format("2006-01-02 15:04:05"))

	starttime, _ := redis.String(conn.Do("GET", "abc:starttime"))
	log.Println(starttime)

	for i := 0; i < 10; i++ {
		conn.Do("LPUSH", "abc:list", i)
	}

	for i := 0; i < 11; i++ {
		r, err := redis.Int64(conn.Do("rpop", "abc:list"))
		if err == nil {
			log.Println(r)
		} else {
			log.Println(err)
		}
	}

	//for i := 0; i < 2; i++ {
	//	log.Println(redis.Strings(conn.Do("BRPOP", "abc:list", 0)))
	//	log.Println(redis.StringMap(conn.Do("BRPOP", "abc:list", 0)))
	//}

	// map
	//conn.Do("hmset", "abc:set", "key1", "val1", "key2", "val2", "key3", "val3")
	conn.Do("hmset", "abc:set", redis.Args{}.Add("key1").Add("val1").Add("key2").Add("val2"))
	s, _ := redis.StringMap(conn.Do("hgetall", "abc:set"))
	log.Println(s)
}
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队列

redis 分布式锁实现示例

package main

import (
	"flag"
	"fmt"
	"log"
	"math/rand"
	"os"
	"time"

	"github.com/gomodule/redigo/redis"
	"github.com/google/uuid"
)

var (
	lockKey = "abc:consumer:master"
)

func getRedisConn() (redis.Conn, error) {
	conn, err := redis.Dial("tcp", "100.80.0.128:6379", redis.DialPassword("foobared"))
	if err != nil {
		log.Fatal(err)
		return nil, nil
	}

	return conn, nil
}

// Productor 生产者
func Productor() {
	if conn, err := getRedisConn(); err == nil {
		defer func(conn redis.Conn) {
			err := conn.Close()
			if err != nil {
				log.Fatal("close redis connection for productor err", err)
			}
			log.Println("custom redis connection for productor closed.")
		}(conn)

		pid := os.Getegid()
		for {
			time.Sleep(time.Second * time.Duration(rand.Intn(10)))
			v := fmt.Sprintf("%d %s", pid, time.Now().Format("2006-01-02 15:04:05"))
			conn.Do("lpush", "abc:tasks", v)
			log.Println("push", v)
		}
	} else {
		log.Fatal(err)
	}
}

// Consumer 消费者
func Consumer() {
	conn, err := getRedisConn()
	if err != nil {
		log.Println(err)
		return
	}
	defer func(conn redis.Conn) {
		err := conn.Close()
		if err != nil {
			log.Fatal("close redis connection for consumer err", err)
		}
		log.Println("custom redis connection for consumer closed.")
	}(conn)

	for {
		ruid, err := redis.String(conn.Do("get", lockKey))
		if err != nil || ruid != uid {
			log.Println("I am Slaver")
			time.Sleep(5 * time.Second)
			continue
		}

		if str, err := redis.Strings(conn.Do("brpop", "abc:tasks", 2)); err != nil {
			continue
		} else {
			log.Printf("%#v\n", str)
		}
	}
}

var (
	t   string
	uid string
)

func init() {
	flag.StringVar(&t, "t", "p", "[p|c] productor or customer")
	flag.Parse()

	uid = uuid.New().String()
}

func main() {
	rand.Seed(time.Now().Unix())

	conn, err := getRedisConn()
	if err != nil {
		log.Println(err)
		return
	}
	defer func(conn redis.Conn) {
		err := conn.Close()
		if err != nil {
			log.Fatal("close redis connection for lock err", err)
		}
		log.Println("custom redis connection for lock closed.")
	}(conn)

	// 分布式锁，保证消费者只有一个
	go func() {
		ticker := time.NewTicker(time.Second * 20)
		for {
			ok, err := redis.String(conn.Do("set", lockKey, uid, "EX", 25, "NX"))
			if err != nil || ok != "OK" {
				ruid, err := redis.String(conn.Do("get", lockKey))
				if err == nil && ruid == uid {
					log.Println("I am Master, get")
					// 续期
					ok, err := conn.Do("Expire", lockKey, 30)
					if err != nil {
						log.Println("expire---", ok, err)
						return
					}
				} else {
					log.Println("I am Slave")
				}
			} else {
				log.Println("I am Master, set")
			}
			<-ticker.C
		}
	}()

	if t == "p" {
		log.Println("start Productor...")
		Productor()
	} else {
		log.Println("start Consumer...")
		Consumer()
	}
}
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