Redis Lua同步锁实现源码解析

admin Redis

2023-12-07 0 628

Redis+Lua同步锁

Jedis配置

@Configuration
@Getter
@Setter
@Slf4j
@ConfigurationProperties(prefix = \”jedis\”)
public class JedisConfig {
@Value(\”${spring.redis.host}\”)
private String host;
@Value(\”${spring.redis.port}\”)
private int port;
@Value(\”${spring.redis.password}\”)
private String password;
private int timeout;
private int maxTotal;
private int maxIdle;
private int minIdle;
@Bean
public JedisPool jedisPool() {
JedisPoolConfig jedisPoolConfig = new JedisPoolConfig();
jedisPoolConfig.setMaxIdle(maxIdle);
jedisPoolConfig.setMinIdle(minIdle);
jedisPoolConfig.setMaxTotal(maxTotal);
JedisPool jedisPool = new JedisPool(jedisPoolConfig, host, port, timeout, password);
log.info(\”JedisPool连接成功:\” + host + \”\\t\” + port);
return jedisPool;
}
}

Jedis工具类→获取jedis

@Component
public class JedisUtil {
@Resource
private JedisPool jedisPool;
/**
* 获取Jedis资源
*/
public Jedis getJedis() {
return jedisPool.getResource();
}
/**
* 释放Jedis连接
*/
public void close(Jedis jedis) {
if (jedis != null) {
jedis.close();
}
}
}

redis 锁工具类

public class RedisLockUtil {
private static final Long RELEASE_SUCCESS = 1L;
private static final String PREFIX = \”API_LOCK_\”;
/**
* 释放分布式锁
*
* @param jedis
* @param lockKey
* @param valve
* @return boolean
* @author ll
* @date 2023/02/09 14:31
*/
public static boolean unLock(Jedis jedis, String lockKey, String valve) {
String script = \”if redis.call(\’get\’, KEYS[1]) == ARGV[1] then return redis.call(\’del\’, KEYS[1]) else return 0 end\”;
Object result = jedis.eval(script, Collections.singletonList(PREFIX + lockKey), Collections.singletonList(PREFIX + valve));
if (RELEASE_SUCCESS.equals(result)) {
return true;
}
return false;
}
/**
* 加分布式锁
*
* @param jedis
* @param lockKey
* @param valve
* @param timeout
* @return boolean
* @author ll
* @date 2023/02/09 14:31
*/
public static boolean lock(Jedis jedis, String lockKey, String valve, int timeout) {
String script = \”if redis.call(\’setnx\’,KEYS[1],ARGV[1]) == 1 then\” +
\” redis.call(\’expire\’,KEYS[1],ARGV[2]) return 1 else return 0 end\”;
Object result = jedis.eval(script, Collections.singletonList(PREFIX + lockKey), Lists.newArrayList(PREFIX + valve, String.valueOf(timeout)));
//判断是否成功
if (RELEASE_SUCCESS.equals(result)) {
return true;
}
return false;
}
}

加锁示例(jedis+lua)

@Slf4j
@Component
public class InterfaceEventListener {
@Resource
private JedisUtil jedisUtil;
@Value(\”${jedis.lock.cycle-number}\”)
private int cycleNumber;
@Value(\”${jedis.lock.expire-time}\”)
private int expireTime;
@Value(\”${jedis.lock.sleep-time}\”)
private int sleepTime;
@Value(\”${spring.redis.database}\”)
private int database;
public void onApplicationEvent(InterfaceEvent event) {
Jedis jedis = jedisUtil.getJedis();
jedis.select(database);
boolean unLock = false;
boolean lock;
int currentNumber = 0;
try {
do {
lock = RedisLockUtil.lock(jedis, \”lockKey\”, \”valve\”, expireTime);
if (lock) {
try {
//todo 加锁的代码
} catch (Exception e) {
log.error(e.getMessage());
e.printStackTrace();
} finally {
unLock = RedisLockUtil.unLock(jedis, detectCode, detectCode);
}
}
currentNumber++;
Thread.sleep(sleepTime);
}
while (!unLock && currentNumber < cycleNumber);
} catch (Exception e) {
e.printStackTrace();
log.error(e.getMessage());
} finally {
jedisUtil.close(jedis);
}
}
}