Golang和Redis配合真的好吗?

Golang操作Redis

安装第三方开源Redis库

• 使用第三方开源的redis库 : github.com/garyburd/redigo/redis
• 在使用Redis前,先安装第三方Redis库,在Gopath路径下执行安装指令:

go get github.com/garyburd/redigo/redis

• 安装成功后,可以看到如下包
  

Golang操作Redis

连接

Conn接口是与Redis协作的主要接口，可以使用Dial,DialWithTimeout或者NewConn函数来创建连接，当任务完成时，应用程序必须调用Close函数来完成操作。

package main

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


func main()  {
    conn,err := redis.Dial("tcp","localhost:6379")
    if err != nil {
        fmt.Println("connect redis error :",err)
        return
    }
    defer conn.Close()
}

命令操作

通过使用Conn接口中的do方法执行redis命令
redis命令大全参考：http://doc.redisfans.com/

go中发送与响应对应类型

Do函数会必要时将参数转化为二进制字符串

Go Type	Conversion
[]byte	Sent as is
string	Sent as is
int, int64	strconv.FormatInt(v)
float64	strconv.FormatFloat(v, ‘g’, -1, 64)
bool	true -> “1”, false -> “0”
nil	“”
all	other types fmt.Print(v)

Redis 命令响应会用以下Go类型表示：

Redis type	Go type
error	redis.Error
integer	int64
simple string	string
bulk string	[]byte or nil if value not present.
array	[]interface{} or nil if value not present.

可以使用GO的类型断言或者reply辅助函数将返回的interface{}转换为对应类型。

package main

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

func main()  {
    conn,err := redis.Dial("tcp","10.1.210.69:6379")
    if err != nil {
        fmt.Println("connect redis error :",err)
        return
    }
    defer conn.Close()
    _, err = conn.Do("SET", "name", "wd")
    if err != nil {
        fmt.Println("redis set error:", err)
    }
    name, err := redis.String(conn.Do("GET", "name"))
    if err != nil {
        fmt.Println("redis get error:", err)
    } else {
        fmt.Printf("Got name: %s \n", name)
    }
}

设置key过期时间

 _, err = conn.Do("expire", "name", 10) //10秒过期
    if err != nil {
        fmt.Println("set expire error: ", err)
        return
    }

批量获取mget、批量设置mset

_, err = conn.Do("MSET", "name", "wd","age",22)
    if err != nil {
        fmt.Println("redis mset error:", err)
    }
    res, err := redis.Strings(conn.Do("MGET", "name","age"))
    if err != nil {
        fmt.Println("redis get error:", err)
    } else {
        res_type := reflect.TypeOf(res)
        fmt.Printf("res type : %s \n", res_type)
        fmt.Printf("MGET name: %s \n", res)
        fmt.Println(len(res))
    }
//结果：
//res type : []string 
//MGET name: [wd 22] 
//2

列表操作

package main

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


func main()  {
    conn,err := redis.Dial("tcp","10.1.210.69:6379")
    if err != nil {
        fmt.Println("connect redis error :",err)
        return
    }
    defer conn.Close()
    _, err = conn.Do("LPUSH", "list1", "ele1","ele2","ele3")
    if err != nil {
        fmt.Println("redis mset error:", err)
    }
    res, err := redis.String(conn.Do("LPOP", "list1"))
    if err != nil {
        fmt.Println("redis POP error:", err)
    } else {
        res_type := reflect.TypeOf(res)
        fmt.Printf("res type : %s \n", res_type)
        fmt.Printf("res  : %s \n", res)
    }
}
//res type : string 
//res  : ele3 

hash操作

package main

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


func main()  {
    conn,err := redis.Dial("tcp","10.1.210.69:6379")
    if err != nil {
        fmt.Println("connect redis error :",err)
        return
    }
    defer conn.Close()
    _, err = conn.Do("HSET", "student","name", "wd","age",22)
    if err != nil {
        fmt.Println("redis mset error:", err)
    }
    res, err := redis.Int64(conn.Do("HGET", "student","age"))
    if err != nil {
        fmt.Println("redis HGET error:", err)
    } else {
        res_type := reflect.TypeOf(res)
        fmt.Printf("res type : %s \n", res_type)
        fmt.Printf("res  : %d \n", res)
    }
}
//res type : int64 
//res  : 22 

Pipelining(管道)

管道操作可以理解为并发操作，并通过Send()，Flush()，Receive()三个方法实现。客户端可以使用send()方法一次性向服务器发送一个或多个命令，命令发送完毕时，使用flush()方法将缓冲区的命令输入一次性发送到服务器，客户端再使用Receive()方法依次按照先进先出的顺序读取所有命令操作结果。

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

• Send：发送命令至缓冲区
• Flush：清空缓冲区，将命令一次性发送至服务器
• Recevie：依次读取服务器响应结果，当读取的命令未响应时，该操作会阻塞。

package main

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


func main()  {
    conn,err := redis.Dial("tcp","10.1.210.69:6379")
    if err != nil {
        fmt.Println("connect redis error :",err)
        return
    }
    defer conn.Close()
    conn.Send("HSET", "student","name", "wd","age","22")
    conn.Send("HSET", "student","Score","100")
    conn.Send("HGET", "student","age")
    conn.Flush()

    res1, err := conn.Receive()
    fmt.Printf("Receive res1:%v \n", res1)
    res2, err := conn.Receive()
    fmt.Printf("Receive res2:%v\n",res2)
    res3, err := conn.Receive()
    fmt.Printf("Receive res3:%s\n",res3)
}
//Receive res1:0 
//Receive res2:0
//Receive res3:22

发布/订阅

redis本身具有发布订阅的功能，其发布订阅功能通过命令SUBSCRIBE(订阅)／PUBLISH(发布)实现，并且发布订阅模式可以是多对多模式还可支持正则表达式，发布者可以向一个或多个频道发送消息，订阅者可订阅一个或者多个频道接受消息。

发布者

订阅者

##	操作
package main

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

func Subs() {  //订阅者
    conn, err := redis.Dial("tcp", "10.1.210.69:6379")
    if err != nil {
        fmt.Println("connect redis error :", err)
        return
    }
    defer conn.Close()
    psc := redis.PubSubConn{conn}
    psc.Subscribe("channel1") //订阅channel1频道
    for {
        switch v := psc.Receive().(type) {
        case redis.Message:
            fmt.Printf("%s: message: %s\n", v.Channel, v.Data)
        case redis.Subscription:
            fmt.Printf("%s: %s %d\n", v.Channel, v.Kind, v.Count)
        case error:
            fmt.Println(v)
            return
        }
    }
}

func Push(message string)  { //发布者
    conn, _ := redis.Dial("tcp", "10.1.210.69:6379")
    _,err1 := conn.Do("PUBLISH", "channel1", message)
       if err1 != nil {
             fmt.Println("pub err: ", err1)
                 return
            }

}

func main()  {
    go Subs()
    go Push("this is wd")
    time.Sleep(time.Second*3)
}
//channel1: subscribe 1
//channel1: message: this is wd

事务操作

MULTI, EXEC,DISCARD和WATCH是构成Redis事务的基础，当然我们使用go语言对redis进行事务操作的时候本质也是使用这些命令。

• MULTI：开启事务
• EXEC：执行事务
• DISCARD：取消事务
• WATCH：监视事务中的键变化，一旦有改变则取消事务。

package main

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


func main()  {
    conn,err := redis.Dial("tcp","10.1.210.69:6379")
    if err != nil {
        fmt.Println("connect redis error :",err)
        return
    }
    defer conn.Close()
    conn.Send("MULTI")
    conn.Send("INCR", "foo")
    conn.Send("INCR", "bar")
    r, err := conn.Do("EXEC")
    fmt.Println(r)
}
//[1, 1]

连接池使用

redis连接池是通过pool结构体实现，以下是源码定义，相关参数说明已经备注：

type Pool struct {
    // Dial is an application supplied function for creating and configuring a
    // connection.
    //
    // The connection returned from Dial must not be in a special state
    // (subscribed to pubsub channel, transaction started, ...).
    Dial func() (Conn, error) //连接方法

    // TestOnBorrow is an optional application supplied function for checking
    // the health of an idle connection before the connection is used again by
    // the application. Argument t is the time that the connection was returned
    // to the pool. If the function returns an error, then the connection is
    // closed.
    TestOnBorrow func(c Conn, t time.Time) error

    // Maximum number of idle connections in the pool.
    MaxIdle int  //最大的空闲连接数，即使没有redis连接时依然可以保持N个空闲的连接，而不被清除，随时处于待命状态

    // Maximum number of connections allocated by the pool at a given time.
    // When zero, there is no limit on the number of connections in the pool.
    MaxActive int //最大的激活连接数，同时最多有N个连接

    // Close connections after remaining idle for this duration. If the value
    // is zero, then idle connections are not closed. Applications should set
    // the timeout to a value less than the server's timeout.
    IdleTimeout time.Duration  //空闲连接等待时间，超过此时间后，空闲连接将被关闭

    // If Wait is true and the pool is at the MaxActive limit, then Get() waits
    // for a connection to be returned to the pool before returning.
    Wait bool  //当配置项为true并且MaxActive参数有限制时候，使用Get方法等待一个连接返回给连接池

    // Close connections older than this duration. If the value is zero, then
    // the pool does not close connections based on age.
    MaxConnLifetime time.Duration
    // contains filtered or unexported fields
    }

代码实现

package main

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

var Pool redis.Pool
func init()  {      //init 用于初始化一些参数，先于main执行
    Pool = redis.Pool{
        MaxIdle:     16,
        MaxActive:   32,
        IdleTimeout: 120,
        Dial: func() (redis.Conn, error) {
            return redis.Dial("tcp", "10.1.210.69:6379")
        },
    }
}

func main()  {

    conn :=Pool.Get()
    res,err := conn.Do("HSET","student","name","jack")
    fmt.Println(res,err)
    res1,err := redis.String(conn.Do("HGET","student","name"))
    fmt.Printf("res:%s,error:%v",res1,err)

}
//0 
//res:jack,error: