Go实战--golang中使用redis(redigo和go-redis/redis)

开源库redigo的使用

github地址：
https://github.com/garyburd/redigo

文档地址：
http://godoc.org/github.com/garyburd/redigo/redis

获取：

go get github.com/garyburd/redigo/redis

连接redis

package main
import (
    "fmt"
    "github.com/garyburd/redigo/redis"
)

func main() {
    c, err := redis.Dial("tcp", "127.0.0.1:6379")
    if err != nil {
        fmt.Println("Connect to redis error", err)
        return
    }
    defer c.Close()
}

读写
这里写入的值永远不会过期

package main

import (
    "fmt"

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

func main() {
    c, err := redis.Dial("tcp", "127.0.0.1:6379")
    if err != nil {
        fmt.Println("Connect to redis error", err)
        return
    }
    defer c.Close()

    _, err = c.Do("SET", "mykey", "superWang")
    if err != nil {
        fmt.Println("redis set failed:", err)
    }

    username, err := redis.String(c.Do("GET", "mykey"))
    if err != nil {
        fmt.Println("redis get failed:", err)
    } else {
        fmt.Printf("Get mykey: %v \n", username)
    }
}

如何设置过期呢，可以使用SET的附加参数：

package main

import (
    "fmt"
    "time"

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

func main() {
    c, err := redis.Dial("tcp", "127.0.0.1:6379")
    if err != nil {
        fmt.Println("Connect to redis error", err)
        return
    }
    defer c.Close()

    _, err = c.Do("SET", "mykey", "superWang", "EX", "5")
    if err != nil {
        fmt.Println("redis set failed:", err)
    }

    username, err := redis.String(c.Do("GET", "mykey"))
    if err != nil {
        fmt.Println("redis get failed:", err)
    } else {
        fmt.Printf("Get mykey: %v \n", username)
    }

    time.Sleep(8 * time.Second)

    username, err = redis.String(c.Do("GET", "mykey"))
    if err != nil {
        fmt.Println("redis get failed:", err)
    } else {
        fmt.Printf("Get mykey: %v \n", username)
    }
}

输出：
Get mykey: superWang
redis get failed: redigo: nil returned

批量写入读取

MGET key [key …]
MSET key value [key value …]

批量写入读取对象(Hashtable)
HMSET key field value [field value …]
HMGET key field [field …]

检测值是否存在
EXISTS key

package main

import (
    "fmt"

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

func main() {
    c, err := redis.Dial("tcp", "127.0.0.1:6379")
    if err != nil {
        fmt.Println("Connect to redis error", err)
        return
    }
    defer c.Close()

    _, err = c.Do("SET", "mykey", "superWang")
    if err != nil {
        fmt.Println("redis set failed:", err)
    }

    is_key_exit, err := redis.Bool(c.Do("EXISTS", "mykey1"))
    if err != nil {
        fmt.Println("error:", err)
    } else {
        fmt.Printf("exists or not: %v \n", is_key_exit)
    }

}

输出：
exists or not: false

删除
DEL key [key …]

package main

import (
    "fmt"

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

func main() {
    c, err := redis.Dial("tcp", "127.0.0.1:6379")
    if err != nil {
        fmt.Println("Connect to redis error", err)
        return
    }
    defer c.Close()

    _, err = c.Do("SET", "mykey", "superWang")
    if err != nil {
        fmt.Println("redis set failed:", err)
    }

    username, err := redis.String(c.Do("GET", "mykey"))
    if err != nil {
        fmt.Println("redis get failed:", err)
    } else {
        fmt.Printf("Get mykey: %v \n", username)
    }

    _, err = c.Do("DEL", "mykey")
    if err != nil {
        fmt.Println("redis delelte failed:", err)
    }

    username, err = redis.String(c.Do("GET", "mykey"))
    if err != nil {
        fmt.Println("redis get failed:", err)
    } else {
        fmt.Printf("Get mykey: %v \n", username)
    }
}

输出：
Get mykey: superWang
redis get failed: redigo: nil returned

读写json到redis

package main

import (
    "encoding/json"
    "fmt"

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

func main() {
    c, err := redis.Dial("tcp", "127.0.0.1:6379")
    if err != nil {
        fmt.Println("Connect to redis error", err)
        return
    }
    defer c.Close()

    key := "profile"
    imap := map[string]string{"username": "666", "phonenumber": "888"}
    value, _ := json.Marshal(imap)

    n, err := c.Do("SETNX", key, value)
    if err != nil {
        fmt.Println(err)
    }
    if n == int64(1) {
        fmt.Println("success")
    }

    var imapGet map[string]string

    valueGet, err := redis.Bytes(c.Do("GET", key))
    if err != nil {
        fmt.Println(err)
    }

    errShal := json.Unmarshal(valueGet, &imapGet)
    if errShal != nil {
        fmt.Println(err)
    }
    fmt.Println(imapGet["username"])
    fmt.Println(imapGet["phonenumber"])
}

设置过期时间
EXPIRE key seconds

// 设置过期时间为24小时
n, _ := rs.Do("EXPIRE", key, 24*3600)
if n == int64(1) {
    fmt.Println("success")
}

列表操作
命令：

redis 127.0.0.1:6379> LPUSH runoobkey redis
(integer) 1
redis 127.0.0.1:6379> LPUSH runoobkey mongodb
(integer) 2
redis 127.0.0.1:6379> LPUSH runoobkey mysql
(integer) 3
redis 127.0.0.1:6379> LRANGE runoobkey 0 10

1) "mysql"
2) "mongodb"
3) "redis"

代码实现：

package main

import (
    "fmt"

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

func main() {
    c, err := redis.Dial("tcp", "127.0.0.1:6379")
    if err != nil {
        fmt.Println("Connect to redis error", err)
        return
    }
    defer c.Close()

    _, err = c.Do("lpush", "runoobkey", "redis")
    if err != nil {
        fmt.Println("redis set failed:", err)
    }

    _, err = c.Do("lpush", "runoobkey", "mongodb")
    if err != nil {
        fmt.Println("redis set failed:", err)
    }
    _, err = c.Do("lpush", "runoobkey", "mysql")
    if err != nil {
        fmt.Println("redis set failed:", err)
    }

    values, _ := redis.Values(c.Do("lrange", "runoobkey", "0", "100"))

    for _, v := range values {
        fmt.Println(string(v.([]byte)))
    }
}

输出：
mysql
mongodb
redis

管道

请求/响应服务可以实现持续处理新请求，即使客户端没有准备好读取旧响应。这样客户端可以发送多个命令到服务器而无需等待响应，最后在一次读取多个响应。这就是管道化(pipelining)，这个技术在多年就被广泛使用了。距离，很多POP3协议实现已经支持此特性，显著加速了从服务器下载新邮件的过程。
Redis很早就支持管道化，所以无论你使用任何版本，你都可以使用管道化技术

连接支持使用Send()，Flush()，Receive()方法支持管道化操作

Send(commandName string, args ...interface{}) error
Flush() error
Receive() (reply interface{}, err error)

Send向连接的输出缓冲中写入命令。Flush将连接的输出缓冲清空并写入服务器端。Recevie按照FIFO顺序依次读取服务器的响应。下例展示了一个简单的管道：

c.Send("SET", "foo", "bar")
c.Send("GET", "foo")
c.Flush()
c.Receive() // reply from SET
v, err = c.Receive() // reply from GET

Do方法组合了Send,Flush和 Receive方法。Do方法先写入命令，然后清空输出buffer，最后接收全部挂起响应包括Do方发出的命令的结果。如果任何响应中包含一个错误，Do返回错误。如果没有错误，Do方法返回最后一个响应。

开源库go-redis/redis的使用

github地址：
https://github.com/go-redis/redis

文档地址：
https://godoc.org/github.com/go-redis/redis

获取：

go get -u github.com/go-redis/redis

应用：

package main

import (
    "fmt"

    "github.com/go-redis/redis"
)

func main() {
    client := redis.NewClient(&redis.Options{
        Addr:     "127.0.0.1:6379",
        Password: "", // no password set
        DB:       0,  // use default DB
    })

    pong, err := client.Ping().Result()
    fmt.Println(pong, err)

    err = client.Set("key", "value", 0).Err()
    if err != nil {
        panic(err)
    }

    val, err := client.Get("key").Result()
    if err != nil {
        panic(err)
    }
    fmt.Println("key", val)

    val2, err := client.Get("key2").Result()
    if err == redis.Nil {
        fmt.Println("key2 does not exists")
    } else if err != nil {
        panic(err)
    } else {
        fmt.Println("key2", val2)
    }
}

输出：
PONG
key value
key2 does not exists