优化的点是,序列号不是每次都归0,而是归一个0到100的随机数。 //如果当前操作落在同一个ms(timestamp位相同)的话if(lastTimestamp == currentTimestamp) {//sequence++ 且 保证不溢出,下面测试可知道如果溢出了maxSequence就会变成0sequence = (sequence +1) & maxSequence;if(sequence ==0) {// overflow...
throw new UnsupportedOperationException("Timestamp bitsis exhausted. Refusing ID generate. Now: " + currentTimestamp); } return currentTimestamp; } private long tilNextMillis(long lastTimestamp) { long timestamp = timeGen(); while (timestamp <= lastTimestamp) { timestamp = timeGen(); } r...
throw new UnsupportedOperationException("Timestamp bits is exhausted. Refusing ID generate. Now: " + currentTimestamp); } return currentTimestamp; } private long tilNextMillis(long lastTimestamp) { long timestamp = timeGen(); while (timestamp <= lastTimestamp) { timestamp = timeGen(); } ...
//获取计算id时刻的时间戳 long timestamp = System.currentTimeMillis();if (timestamp <lastTimesta...
//时间戳需要左移位数 12+5+5=22位privatelongtimestampLeftShift=sequenceBits+workerIdBits+datacenterIdBits;//上次时间戳,初始值为负数privatelonglastTimestamp=-1L;publiclonggetWorkerId(){returnworkerId;}publiclonggetDatacenterId(){returndatacenterId;}publiclonggetTimestamp(){returnSystem.currentTimeMillis...
timestampBitLeftOffset = idcBitNum + machineBitNum + sequenceBitNum; this.idcId = idcId; this.machineId = machineId; } // 产生下一个ID public long nextId() { long currentStamp = getTimeMill(); if (currentStamp < lastStamp) { ...
public long getTimestamp() { return System.currentTimeMillis(); } //下一个ID生成算法 public synchronized long nextId() { long timestamp = timeGen(); //获取当前时间戳如果小于上次时间戳,则表示时间戳获取出现异常 if (timestamp < lastTimestamp) { ...
* @param lastTimestamp * @return */privatelongtilNextMillis(longlastTimestamp){longtimestamp=timeGen();while(timestamp<=lastTimestamp){timestamp=timeGen();}returntimestamp;}//获取当前时间戳privatelongtimeGen(){returnSystem.currentTimeMillis();}/** ...
((当前时间 - 服务时间) << timestampLeftShift) | (机器ID << workerIdShift) | sequence; 服务时间指的是服务的开发时间,即第一个正式ID产生的时间。由于SnowFlakeID最长可用69年(因为只有41个bit,41个bit的最大值换算成年就是69年)。所以服务时间越贴近上线时间,则该算法可用时间越长。
1、获取当前时间戳GET TIME STAMP FIELD timestamp...获取当前系统的时间戳(这里的时间戳可以是长类型,也可以是短类型) 示例: GET TIIME STAMP FIELD lv_timestamp. 2、使用CONVERT DATE生成指定时间的时间戳CONVERT...根据指定的日期、时间(可选是否为夏令时)和时区生成时间戳,其中[]圈起来的参数为...