Golang でデータの一貫性を実現するために分散キャッシュ テクノロジを使用する実践。

package main

import (
   "fmt"
   "github.com/gomodule/redigo/redis"
   "sync"
)

var pool *redis.Pool

// 初始化连接池
func InitRedisPool(address string, password string) {
    pool = &redis.Pool{
        MaxIdle:     3,
        MaxActive:   5,
        IdleTimeout: 300,
        Dial: func() (redis.Conn, error) {
            c, err := redis.Dial("tcp", address)
            if err != nil {
                return nil, err
            }
            if password != "" {
                if _, err := c.Do("AUTH", password); err != nil {
                    c.Close()
                    return nil, err
                }
            }
            return c, nil
        },
        TestOnBorrow: func(c redis.Conn, t time.Time) error {
            _, err := c.Do("PING")
            return err
        },
    }
}

// 加锁，防止多个请求写同一份数据产生不一致
func Lock(name string) {
    conn := pool.Get()
    defer conn.Close()
    for {
        locked, err := redis.Int(conn.Do("SETNX", name, 1))
        if err != nil || locked == 1 {
            break
        }
        time.Sleep(time.Millisecond * 50)
    }
}

// 解锁，释放锁
func Unlock(name string) {
    conn := pool.Get()
    defer conn.Close()
    conn.Do("DEL", name)
}

// 获取数据
func GetDataFromCache(key string) (string, error) {
    conn := pool.Get()
    defer conn.Close()
    value, err := redis.String(conn.Do("GET", key))
    if err != nil {
        return "", err
    }
    return value, nil
}

// 设置数据
func SetDataToCache(key string, value string) error {
    conn := pool.Get()
    defer conn.Close()
    _, err := conn.Do("SET", key, value)
    if err != nil {
        return err
    }
    return nil
}

func main() {
    InitRedisPool("localhost:6379", "")
    
    var wg sync.WaitGroup
    for i := 0; i < 10; i++ {
        wg.Add(1)
        go func(num int) {
            Lock("test")
            defer Unlock("test")
            value, err := GetDataFromCache("number")
            if err == nil {
                num, _ := strconv.Atoi(value)
                SetDataToCache("number", strconv.Itoa(num+1))
            }
            wg.Done()
        }(i)
    }
    wg.Wait()
    
    number, _ := GetDataFromCache("number")
    fmt.Println("The number is", number)
}