Go语言学习笔记（八）golang 操作 Redis & Mysql & RabbitMQ

时间：2021-01-30 16:25:34

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Reids

安装导入

go get github.com/garyburd/redigo/redis

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

链接

github：https://github.com/antirez/redis

Doc：http://godoc.org/github.com/garyburd/redigo/redis

Redis全套使用：http://www.cnblogs.com/suoning/p/5807247.html

使用

连接

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

func main() {

    c, err := redis.Dial("tcp", "localhost:6379")

    if err != nil {

        fmt.Println("conn redis failed, err:", err)

        return

    }

    defer c.Close()

}

set & get

        _, err = c.Do("Set", "name", "nick")

    if err != nil {

        fmt.Println(err)

        return

    }

    r, err := redis.String(c.Do("Get", "name"))

    if err != nil {

        fmt.Println(err)

        return

    }

    fmt.Println(r)

mset & mget

批量设置

        _, err = c.Do("MSet", "name", "nick", "age", "")

    if err != nil {

        fmt.Println("MSet error: ", err)

        return

    }

    r2, err := redis.Strings(c.Do("MGet", "name", "age"))

    if err != nil {

        fmt.Println("MGet error: ", err)

        return

    }

    fmt.Println(r2)

hset & hget

hash操作

    _, err = c.Do("HSet", "names", "nick", "suoning")

    if err != nil {

        fmt.Println("hset error: ", err)

        return

    }

    r, err = redis.String(c.Do("HGet", "names", "nick"))

    if err != nil {

        fmt.Println("hget error: ", err)

        return

    }

    fmt.Println(r)

expire

设置过期时间

    _, err = c.Do("expire", "names", )

    if err != nil {

        fmt.Println("expire error: ", err)

        return

    }

lpush & lpop & llen

队列

    // 队列

    _, err = c.Do("lpush", "Queue", "nick", "dawn", )

    if err != nil {

        fmt.Println("lpush error: ", err)

        return

    }

    for {

        r, err = redis.String(c.Do("lpop", "Queue"))

        if err != nil {

            fmt.Println("lpop error: ", err)

            break

        }

        fmt.Println(r)

    }

    r3, err := redis.Int(c.Do("llen", "Queue"))

    if err != nil {

        fmt.Println("llen error: ", err)

        return

    }

连接池

各参数的解释如下：

MaxIdle：最大的空闲连接数，表示即使没有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。

MaxActive：最大的激活连接数，表示同时最多有N个连接

IdleTimeout：最大的空闲连接等待时间，超过此时间后，空闲连接将被关闭

    pool := &redis.Pool{

        MaxIdle:     ,

        MaxActive:   ,

        IdleTimeout: ,

        Dial: func() (redis.Conn, error) {

            return redis.Dial("tcp", "localhost:6379")

        },

    }

连接池栗子

package main

import (

    "fmt"

    "github.com/garyburd/redigo/redis"

)

var pool *redis.Pool

func init() {

    pool = &redis.Pool{

        MaxIdle:     ,

        MaxActive:   ,

        IdleTimeout: ,

        Dial: func() (redis.Conn, error) {

            return redis.Dial("tcp", "localhost:6379")

        },

    }

}

func main() {

    c := pool.Get()

    defer c.Close()

    _, err := c.Do("Set", "name", "nick")

    if err != nil {

        fmt.Println(err)

        return

    }

    r, err := redis.String(c.Do("Get", "name"))

    if err != nil {

        fmt.Println(err)

        return

    }

    fmt.Println(r)

}

管道操作

请求/响应服务可以实现持续处理新请求，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。

使用Send()，Flush()，Receive()方法支持管道化操作

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。

func main() {

    c, err := redis.Dial("tcp", "localhost:6379")

    if err != nil {

        fmt.Println("conn redis failed, err:", err)

        return

    }

    defer c.Close()

    c.Send("SET", "name1", "sss1")

    c.Send("SET", "name2", "sss2")

    c.Flush()

    v, err := c.Receive()

    fmt.Printf("v:%v,err:%v\n", v, err)

    v, err = c.Receive()

    fmt.Printf("v:%v,err:%v\n", v, err)

    v, err = c.Receive()    // 夯住，一直等待

    fmt.Printf("v:%v,err:%v\n", v, err)

}

Mysql

安装导入

go get "github.com/go-sql-driver/mysql"

go get "github.com/jmoiron/sqlx"

import (

    _ "github.com/go-sql-driver/mysql"

    "github.com/jmoiron/sqlx"

)

链接：

github：

　　https://github.com/go-sql-driver/mysql

　　https://github.com/jmoiron/sqlx

Doc：

http://godoc.org/github.com/jmoiron/sqlx

　　http://jmoiron.github.io/sqlx/

Mysql全套使用：http://www.cnblogs.com/suoning/p/5769141.html

连接

import (

    _ "github.com/go-sql-driver/mysql"

    "github.com/jmoiron/sqlx"

)

var Db *sqlx.DB

func init() {

    database, err := sqlx.Open("mysql", "root:@tcp(127.0.0.1:3306)/test")

    if err != nil {

        fmt.Println("open mysql failed,", err)

        return

    }

    Db = database

}

栗子建表

CREATE TABLE `person` (

  `user_id` int() DEFAULT NULL,

  `username` varchar() DEFAULT NULL,

  `sex` varchar() DEFAULT NULL,

  `email` varchar() DEFAULT NULL

) ENGINE=InnoDB DEFAULT CHARSET=utf8

栗子（insert）

package main

import (

    "fmt"

    _ "github.com/go-sql-driver/mysql"

    "github.com/jmoiron/sqlx"

)

type Person struct {

    UserId   int    `db:"user_id"`

    Username string `db:"username"`

    Sex      string `db:"sex"`

    Email    string `db:"email"`

}

var Db *sqlx.DB

func init() {

    database, err := sqlx.Open("mysql", "root:@tcp(127.0.0.1:3306)/test")

    if err != nil {

        fmt.Println("open mysql failed,", err)

        return

    }

    Db = database

}

func main() {

    r, err := Db.Exec("insert into person(username, sex, email)values(?, ?, ?)", "suoning", "man", "suoning@net263.com")

    if err != nil {

        fmt.Println("exec failed, ", err)

        return

    }

    id, err := r.LastInsertId()

    if err != nil {

        fmt.Println("exec failed, ", err)

        return

    }

    fmt.Println("insert succ:", id)

}

栗子（update）

package main

import (

    "fmt"

    _ "github.com/go-sql-driver/mysql"

    "github.com/jmoiron/sqlx"

)

type Person struct {

    UserId   int    `db:"user_id"`

    Username string `db:"username"`

    Sex      string `db:"sex"`

    Email    string `db:"email"`

}

var Db *sqlx.DB

func init() {

    database, err := sqlx.Open("mysql", "root:@tcp(127.0.0.1:3306)/test")

    if err != nil {

        fmt.Println("open mysql failed,", err)

        return

    }

    Db = database

}

func main() {

    _, err := Db.Exec("update person set user_id=? where username=?", , "suoning")

    if err != nil {

        fmt.Println("exec failed, ", err)

        return

    }

}

栗子（select）

package main

import (

    "fmt"

    _ "github.com/go-sql-driver/mysql"

    "github.com/jmoiron/sqlx"

)

type Person struct {

    UserId   int    `db:"user_id"`

    Username string `db:"username"`

    Sex      string `db:"sex"`

    Email    string `db:"email"`

}

type Place struct {

    Country string `db:"country"`

    City    string `db:"city"`

    TelCode int    `db:"telcode"`

}

var Db *sqlx.DB

func init() {

    database, err := sqlx.Open("mysql", "root:@tcp(127.0.0.1:3306)/test")

    if err != nil {

        fmt.Println("open mysql failed,", err)

        return

    }

    Db = database

}

func main() {

    var person []Person

    err := Db.Select(&person, "select user_id, username, sex, email from person where user_id=?", )

    if err != nil {

        fmt.Println("exec failed, ", err)

        return

    }

    fmt.Println("select succ:", person)

    people := []Person{}

    Db.Select(&people, "SELECT * FROM person ORDER BY user_id ASC")

    fmt.Println(people)

    jason, john := people[], people[]

    fmt.Printf("%#v\n%#v", jason, john)

}

栗子（delete）

package main

import (

    "fmt"

    _ "github.com/go-sql-driver/mysql"

    "github.com/jmoiron/sqlx"

)

type Person struct {

    UserId   int    `db:"user_id"`

    Username string `db:"username"`

    Sex      string `db:"sex"`

    Email    string `db:"email"`

}

var Db *sqlx.DB

func init() {

    database, err := sqlx.Open("mysql", "root:@tcp(127.0.0.1:3306)/test")

    if err != nil {

        fmt.Println("open mysql failed,", err)

        return

    }

    Db = database

}

func main() {

    _, err := Db.Exec("delete from person where username=? limit 1", "suoning")

    if err != nil {

        fmt.Println("exec failed, ", err)

        return

    }

    fmt.Println("delete succ")

}

事务

package main

import (

    "github.com/astaxie/beego/logs"

    _ "github.com/go-sql-driver/mysql"

    "github.com/jmoiron/sqlx"

)

var Db *sqlx.DB

func init() {

    database, err := sqlx.Open("mysql", "root:@tcp(127.0.0.1:3306)/test")

    if err != nil {

        logs.Error("open mysql failed,", err)

        return

    }

    Db = database

}

func main()  {

    conn, err := Db.Begin()

    if err != nil {

        logs.Warn("DB.Begin failed, err:%v", err)

        return

    }

    defer func() {

        if err != nil {

            conn.Rollback()

            return

        }

        conn.Commit()

    }()

    // do something

}

RabbitMQ

安装

go get "github.com/streadway/amqp"

文档：

https://github.com/rabbitmq/rabbitmq-tutorials/tree/master/go

栗子一（普通模式）

生产者：

package main

import (

    "fmt"

    "log"

    "os"

    "strings"

    "github.com/streadway/amqp"

    "time"

)

/*

默认点对点模式

*/

func failOnError(err error, msg string) {

    if err != nil {

        log.Fatalf("%s: %s", msg, err)

        panic(fmt.Sprintf("%s: %s", msg, err))

    }

}

func main() {

    // 连接

    conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")

    failOnError(err, "Failed to connect to RabbitMQ")

    defer conn.Close()

    // 打开一个并发服务器通道来处理消息

    ch, err := conn.Channel()

    failOnError(err, "Failed to open a channel")

    defer ch.Close()

    // 申明一个队列

    q, err := ch.QueueDeclare(

        "task_queue", // name

        true,         // durable  持久性的,如果事前已经声明了该队列，不能重复声明

        false,        // delete when unused

        false,        // exclusive 如果是真，连接一断开，队列删除

        false,        // no-wait

        nil,          // arguments

    )

    failOnError(err, "Failed to declare a queue")

    body := bodyFrom(os.Args)

    // 发布

    err = ch.Publish(

        "",     // exchange 默认模式，exchange为空

        q.Name,           // routing key 默认模式路由到同名队列，即是task_queue

        false,  // mandatory

        false,

        amqp.Publishing{

            // 持久性的发布，因为队列被声明为持久的，发布消息必须加上这个（可能不用），但消息还是可能会丢，如消息到缓存但MQ挂了来不及持久化。

            DeliveryMode: amqp.Persistent,

            ContentType:  "text/plain",

            Body:         []byte(body),

        })

    failOnError(err, "Failed to publish a message")

    log.Printf(" [x] Sent %s", body)

}

func bodyFrom(args []string) string {

    var s string

    if (len(args) < ) || os.Args[] == "" {

        s = fmt.Sprintf("%s-%v","hello", time.Now())

    } else {

        s = strings.Join(args[:], " ")

    }

    return s

}

消费者：

package main

import (

    "bytes"

    "fmt"

    "github.com/streadway/amqp"

    "log"

    "time"

)

/*

默认点对点模式

工作方，多个，拿发布方的消息

*/

func failOnError(err error, msg string) {

    if err != nil {

        log.Fatalf("%s: %s", msg, err)

        panic(fmt.Sprintf("%s: %s", msg, err))

    }

}

func main() {

    conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")

    failOnError(err, "Failed to connect to RabbitMQ")

    defer conn.Close()

    ch, err := conn.Channel()

    failOnError(err, "Failed to open a channel")

    defer ch.Close()

    // 指定队列！

    q, err := ch.QueueDeclare(

        "task_queue", // name

        true,         // durable

        false,        // delete when unused

        false,        // exclusive

        false,        // no-wait

        nil,          // arguments

    )

    failOnError(err, "Failed to declare a queue")

    // Fair dispatch 预取，每个工作方每次拿一个消息，确认后才拿下一次，缓解压力

    err = ch.Qos(

        ,     // prefetch count

        ,     // prefetch size

        false, // global

    )

    failOnError(err, "Failed to set QoS")

    // 消费根据队列名

    msgs, err := ch.Consume(

        q.Name, // queue

        "",     // consumer

        false,  // auto-ack   设置为真自动确认消息

        false,  // exclusive

        false,  // no-local

        false,  // no-wait

        nil,    // args

    )

    failOnError(err, "Failed to register a consumer")

    forever := make(chan bool)

    go func() {

        for d := range msgs {

            log.Printf("Received a message: %s", d.Body)

            dot_count := bytes.Count(d.Body, []byte("."))

            t := time.Duration(dot_count)

            time.Sleep(t * time.Second)

            log.Printf("Done")

            // 确认消息被收到！！如果为真的，那么同在一个channel,在该消息之前未确认的消息都会确认，适合批量处理

            // 真时场景：每十条消息确认一次，类似

            d.Ack(false)

        }

    }()

    log.Printf(" [*] Waiting for messages. To exit press CTRL+C")

    <-forever

}

栗子二（订阅模式）

订阅 生产者：

package main

import (

    "fmt"

    "github.com/streadway/amqp"

    "log"

    "os"

    "strings"

    "time"

)

/*

广播模式

发布方

*/

func failOnError(err error, msg string) {

    if err != nil {

        log.Fatalf("%s: %s", msg, err)

        panic(fmt.Sprintf("%s: %s", msg, err))

    }

}

func main() {

    conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")

    failOnError(err, "Failed to connect to RabbitMQ")

    defer conn.Close()

    ch, err := conn.Channel()

    failOnError(err, "Failed to open a channel")

    defer ch.Close()

    // 默认模式有默认交换机，广播自己定义一个交换机，交换机可与队列进行绑定

    err = ch.ExchangeDeclare(

        "logs",   // name

        "fanout", // type 广播模式

        true,     // durable

        false,    // auto-deleted

        false,    // internal

        false,    // no-wait

        nil,      // arguments

    )

    failOnError(err, "Failed to declare an exchange")

    body := bodyFrom(os.Args)

    // 发布

    err = ch.Publish(

        "logs", // exchange 消息发送到交换机，这个时候没队列绑定交换机，消息会丢弃

        "",     // routing key  广播模式不需要这个，它会把所有消息路由到绑定的所有队列

        false,  // mandatory

        false,  // immediate

        amqp.Publishing{

            ContentType: "text/plain",

            Body:        []byte(body),

        })

    failOnError(err, "Failed to publish a message")

    log.Printf(" [x] Sent %s", body)

}

func bodyFrom(args []string) string {

    var s string

    if (len(args) < ) || os.Args[] == "" {

        s = fmt.Sprintf("%s-%v","hello", time.Now())

    } else {

        s = strings.Join(args[:], " ")

    }

    return s

}

订阅 消费者：

package main

import (

    "fmt"

    "github.com/streadway/amqp"

    "log"

)

/*

广播模式

订阅方

*/

func failOnError(err error, msg string) {

    if err != nil {

        log.Fatalf("%s: %s", msg, err)

        panic(fmt.Sprintf("%s: %s", msg, err))

    }

}

func main() {

    conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")

    failOnError(err, "Failed to connect to RabbitMQ")

    defer conn.Close()

    ch, err := conn.Channel()

    failOnError(err, "Failed to open a channel")

    defer ch.Close()

    // 同样要申明交换机

    err = ch.ExchangeDeclare(

        "logs",   // name

        "fanout", // type

        true,     // durable

        false,    // auto-deleted

        false,    // internal

        false,    // no-wait

        nil,      // arguments

    )

    failOnError(err, "Failed to declare an exchange")

    // 新建队列，这个队列没名字，随机生成一个名字

    q, err := ch.QueueDeclare(

        "",    // name

        false, // durable

        false, // delete when usused

        true,  // exclusive  表示连接一断开，这个队列自动删除

        false, // no-wait

        nil,   // arguments

    )

    failOnError(err, "Failed to declare a queue")

    // 队列和交换机绑定，即是队列订阅了发到这个交换机的消息

    err = ch.QueueBind(

        q.Name, // queue name  队列的名字

        "",     // routing key  广播模式不需要这个

        "logs", // exchange  交换机名字

        false,

        nil)

    failOnError(err, "Failed to bind a queue")

    // 开始消费消息，可开多个订阅方，因为队列是临时生成的，所有每个订阅方都能收到同样的消息

    msgs, err := ch.Consume(

        q.Name, // queue  队列名字

        "",     // consumer

        true,   // auto-ack  自动确认

        false,  // exclusive

        false,  // no-local

        false,  // no-wait

        nil,    // args

    )

    failOnError(err, "Failed to register a consumer")

    forever := make(chan bool)

    go func() {

        for d := range msgs {

            log.Printf(" [x] %s", d.Body)

        }

    }()

    log.Printf(" [*] Waiting for logs. To exit press CTRL+C")

    <-forever

}

栗子三（RPC模式）

RPC 应答方：

package main

import (

    "fmt"

    "log"

    "strconv"

    "github.com/streadway/amqp"

)

/*

RPC模式

应答方

*/

func failOnError(err error, msg string) {

    if err != nil {

        log.Fatalf("%s: %s", msg, err)

        panic(fmt.Sprintf("%s: %s", msg, err))

    }

}

func fib(n int) int {

    if n ==  {

        return

    } else if n ==  {

        return

    } else {

        return fib(n-) + fib(n-)

    }

}

func main() {

    conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")

    failOnError(err, "Failed to connect to RabbitMQ")

    defer conn.Close()

    ch, err := conn.Channel()

    failOnError(err, "Failed to open a channel")

    defer ch.Close()

    q, err := ch.QueueDeclare(

        "rpc_queue", // name

        false,       // durable

        false,       // delete when usused

        false,       // exclusive

        false,       // no-wait

        nil,         // arguments

    )

    failOnError(err, "Failed to declare a queue")

    // 公平分发 没有这个则round-robbin

    err = ch.Qos(

        ,     // prefetch count

        ,     // prefetch size

        false, // global

    )

    failOnError(err, "Failed to set QoS")

    // 消费，等待请求

    msgs, err := ch.Consume(

        q.Name, // queue

        "",     // consumer

        false,  // auto-ack

        false,  // exclusive

        false,  // no-local

        false,  // no-wait

        nil,    // args

    )

    failOnError(err, "Failed to register a consumer")

    forever := make(chan bool)

    go func() {

        //请求来了

        for d := range msgs {

            n, err := strconv.Atoi(string(d.Body))

            failOnError(err, "Failed to convert body to integer")

            log.Printf(" [.] fib(%d)", n)

            // 计算

            response := fib(n)

            // 回答

            err = ch.Publish(

                "",        // exchange

                d.ReplyTo, // routing key

                false,     // mandatory

                false,     // immediate

                amqp.Publishing{

                    ContentType:   "text/plain",

                    CorrelationId: d.CorrelationId,  //序列号

                    Body:          []byte(strconv.Itoa(response)),

                })

            failOnError(err, "Failed to publish a message")

            // 确认回答完毕

            d.Ack(false)

        }

    }()

    log.Printf(" [*] Awaiting RPC requests")

    <-forever

}

RPC 请求方：

package main

import (

    "fmt"

    "log"

    "math/rand"

    "os"

    "strconv"

    "strings"

    "time"

    "github.com/streadway/amqp"

)

/*

RPC模式

请求方

*/

func failOnError(err error, msg string) {

    if err != nil {

        log.Fatalf("%s: %s", msg, err)

        panic(fmt.Sprintf("%s: %s", msg, err))

    }

}

func randomString(l int) string {

    bytes := make([]byte, l)

    for i := ; i < l; i++ {

        bytes[i] = byte(randInt(, ))

    }

    return string(bytes)

}

func randInt(min int, max int) int {

    return min + rand.Intn(max-min)

}

func fibonacciRPC(n int) (res int, err error) {

    conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")

    failOnError(err, "Failed to connect to RabbitMQ")

    defer conn.Close()

    ch, err := conn.Channel()

    failOnError(err, "Failed to open a channel")

    defer ch.Close()

    // 队列声明

    q, err := ch.QueueDeclare(

        "",    // name

        false, // durable

        false, // delete when usused

        true,  // exclusive 为真即连接断开就删除

        false, // noWait

        nil,   // arguments

    )

    failOnError(err, "Failed to declare a queue")

    msgs, err := ch.Consume(

        q.Name, // queue

        "",     // consumer

        true,   // auto-ack

        false,  // exclusive   这个为真，服务器会认为这是该队列唯一的消费者

        false,  // no-local

        false,  // no-wait

        nil,    // args

    )

    failOnError(err, "Failed to register a consumer")

    corrId := randomString()

    err = ch.Publish(

        "",          // exchange

        "rpc_queue", // routing key

        false,       // mandatory

        false,       // immediate

        amqp.Publishing{

            ContentType:   "text/plain",

            CorrelationId: corrId,

            ReplyTo:       q.Name,

            Body:          []byte(strconv.Itoa(n)),

        })

    failOnError(err, "Failed to publish a message")

    for d := range msgs {

        if corrId == d.CorrelationId {

            res, err = strconv.Atoi(string(d.Body))

            failOnError(err, "Failed to convert body to integer")

            break

        }

    }

    return

}

func main() {

    rand.Seed(time.Now().UTC().UnixNano())

    n := bodyFrom(os.Args)

    log.Printf(" [x] Requesting fib(%d)", n)

    res, err := fibonacciRPC(n)

    failOnError(err, "Failed to handle RPC request")

    log.Printf(" [.] Got %d", res)

}

func bodyFrom(args []string) int {

    var s string

    if (len(args) < ) || os.Args[] == "" {

        s = ""

    } else {

        s = strings.Join(args[:], " ")

    }

    n, err := strconv.Atoi(s)

    failOnError(err, "Failed to convert arg to integer")

    return n

}

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