使用RedisAtomicLong优化性能问题
RedisAtomicLong优化性能
在项目中许多过这样的需求,记录留做备忘。
需要创建一个递增序列,这个序列会提供给多个应用来使用,这样就需要保持序列的原子递增。
RedisAtomicLong
spring-data-redis包中提供的,可以对数据中的Long类型进行原子性操作的类,下面是这个类的头:
/**
* Atomic long backed by Redis. Uses Redis atomic increment/decrement and watch/multi/exec operations for CAS
* operations.
* * @see java.util.concurrent.atomic.AtomicLong
* @author Costin Leau
* @author Thomas Darimont
* @author Christoph Strobl
* @author Mark Paluch
*/
public class RedisAtomicLong extends Number implements Serializable, BoundKeyOperations<String> {
我们可以看到java.util.concurrent.atomic.AtomicLong,和java自带的atomic包一样进行原子性操作,两者不同的是:
AtomicLong
只能在一个应用中使用RedisAtomicLong
可以在所有与Redis有连接的应用中使用
开始优化
应用初始化时创建RedisAtomicLong实例。
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//
package com.jiu.common.redis;
import java.util.ArrayList;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.support.atomic.RedisAtomicLong;
public class RedisSequenceFactory {
private static final Logger log = LoggerFactory.getLogger(RedisSequenceFactory.class);
@Autowired
private ObjectRedisTemplate<Integer> redisTemplate;
public RedisSequenceFactory() {
}
public void set(String key, long value) {
RedisAtomicLong counter = new RedisAtomicLong(key, this.redisTemplate.getConnectionFactory());
counter.set(value);
}
public long generate(String key, int increment) {
RedisAtomicLong counter = new RedisAtomicLong(key, this.redisTemplate.getConnectionFactory());
return counter.addAndGet((long)increment);
}
public List<Long> generateBatch(String key, int increment, int size) {
RedisAtomicLong counter = new RedisAtomicLong(key, this.redisTemplate.getConnectionFactory());
long max = counter.addAndGet((long)(increment * size));
long min = max - (long)(increment * (size - 1));
List<Long> list = new ArrayList();
list.add(min);
for(int i = 1; i < size; ++i) {
list.add(min + (long)(increment * i));
}
return list;
}
public long queryValue(String key) {
Integer val = (Integer)this.redisTemplate.get(key);
return val == null ? 0L : (long)val.intValue();
}
}
测试代码
public static String tradeIdIncRedisKey = "order:orderid_inc";
@Test
public long generateId(){
return redisSequenceFactory.generate(tradeIdIncRedisKey,1);
}