Java 类org.springframework.data.redis.core.script.DefaultRedisScript 实例源码

@Override
public void releaseLock(final String lock, final String holder) {
   Assert.notNull(lock, "Pre-condition violated: lock != null.");
   Assert.notNull(holder, "Pre-condition violated: holder != null.");

   // KEYS[1]: key
   // ARGV[1]: value
   DefaultRedisScript<Void> s = new DefaultRedisScript<>(
         "local lock = redis.call('get', KEYS[1]); " +
         "if (lock == ARGV[1]) then " +
            // We own the lock -> We may release it by deleting the lock.
            "redis.call('del', KEYS[1]); " +
         "end;");

   redis.execute(s, keys(key(LOCK, lock)), value(holder));
}

@Override
public boolean tryLock(final String lock, final String holder, final int timeout, final TimeUnit unit) {
   Assert.notNull(lock, "Pre-condition violated: lock != null.");
   Assert.notNull(holder, "Pre-condition violated: holder != null.");
   Assert.isTrue(timeout > 0, "Pre-condition violated: timeout > 0.");
   Assert.notNull(unit, "Pre-condition violated: unit != null.");
   long timeoutMillis = unit.toMillis(timeout);
   Assert.isTrue(timeoutMillis >= 100, "Pre-condition violated: timeoutMillis >= 100.");

   // KEYS[1]: key
   // ARGV[1]: timeout
   // ARGV[2]: value
   DefaultRedisScript<Boolean> s = new DefaultRedisScript<>(
         "local lock = redis.call('get', KEYS[1]); " +
         "if (lock == ARGV[2]) then " +
            // We own the lock -> Refresh expiration.
            "redis.call('pexpire', KEYS[1], ARGV[1]); " +
            "return true; " +
         "end; " +
         "if (lock) then " +
            // Someone else owns the lock -> Abort.
            "return false; " +
         "end; " +
         // No one owns the lock -> Create lock with expiration.
         "redis.call('psetex', KEYS[1], ARGV[1], ARGV[2]); " +
         "return true;",
         Boolean.class);

   return redis.execute(s, keys(key(LOCK, lock)), value(timeoutMillis), value(holder));
}

@Bean
@SuppressWarnings("unchecked")
public RedisScript redisRequestRateLimiterScript() {
    DefaultRedisScript redisScript = new DefaultRedisScript<>();
    redisScript.setScriptSource(new ResourceScriptSource(new ClassPathResource("META-INF/scripts/request_rate_limiter.lua")));
    redisScript.setResultType(List.class);
    return redisScript;
}

private <T> RedisScript<T> getRedisScript(String script, Class<T> resultType) {
    return new DefaultRedisScript<>(script, resultType);
}