[golang] 使用mysql及redis实现简单的分布式锁

有志者，事竟成！如果你在学习数据库，那么本文《[golang] 使用mysql及redis实现简单的分布式锁》，就很适合你！文章讲解的知识点主要包括MySQL、分布式锁、Redis、go，若是你对本文感兴趣，或者是想搞懂其中某个知识点，就请你继续往下看吧~

源码来自

import (
    "errors"
    "time"
    "github.com/go-redis/redis"
)

var redisClient *redis.Client

type redisLock struct {
    name    string
    expiry  time.Duration
}

func (l *redisLock) TryLock() error {
    if ok, _ := redisClient.SetNX(l.name, 1, l.expiry).Result(); !ok {
        return errors.New("redis lock: already locked")
    }

    return nil
}

func (l *redisLock) Unlock() error {
    return redisClient.Del(l.name).Err()
}

MySQL分布式锁

唯一索引是一种索引，它不允许具有索引值相同的行，从而禁止重复的索引或键值。该特性类似于Redis的使用了

import (
    "database/sql"
    "fmt"
    _ "github.com/go-sql-driver/mysql"
    "time"
)

const (
    createTableSql = `
CREATE TABLE IF NOT EXISTS %s (
  id         int          NOT NULL AUTO_INCREMENT,
  name       varchar(255) NOT NULL,
  expire_at  timestamp    NOT NULL,
  created_at timestamp    NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (id),
  UNIQUE KEY uk_name (name) USING HASH,
  KEY idx_expire_at (expire_at) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8
`
    insertRowSql = `
INSERT INTO %s (name, expire_at, created_at) VALUES (?, ?, ?)
`
    deleteRowSql = `
DELETE FROM %s WHERE name=? LIMIT 1
`
)

var lockDb *sql.DB
var lockTableName string

type mysqlLock struct {
    name   string
    expiry time.Duration
}

func (l *mysqlLock) TryLock() error {
    createdAt := time.Now()
    expireAt := createdAt.Add(l.expiry)
    return insertRow(l.name, expireAt, createdAt)
}

func (l *mysqlLock) Unlock() error {
    return deleteRow(l.name)
}

func createTable() error {
    query := fmt.Sprintf(createTableSql, lockTableName)
    _, err := lockDb.Exec(query)
    return err
}

func insertRow(name string, expireAt, createdAt time.Time) error {
    query := fmt.Sprintf(insertRowSql, lockTableName)
    _, err := lockDb.Exec(query, name, expireAt, createdAt)
    return err
}

func deleteRow(name string) error {
    query := fmt.Sprintf(deleteRowSql, lockTableName)
    _, err := lockDb.Exec(query, name)
    return err
}

自旋锁

上面实现的

import (
    "errors"
    "fmt"
    "time"
)

type TryLocker interface {
    TryLock() error
    Unlock() error
}

func NewSpinLock(lock TryLocker, spinTries int, spinInterval time.Duration) *spinLock {
    return &spinLock{
        lock:         lock,
        spinTries:    spinTries,
        spinInterval: spinInterval,
    }
}

type spinLock struct {
    lock         TryLocker
    spinTries    int
    spinInterval time.Duration
}

func (l *spinLock) Lock() error {
    for i := 0; i 

今天带大家了解了MySQL、分布式锁、Redis、go的相关知识，希望对你有所帮助；关于数据库的技术知识我们会一点点深入介绍，欢迎大家关注golang学习网公众号，一起学习编程~