package io.github.id;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* 第一位为未使用（实际上也可作为long的符号位），接下来的41位为毫秒级时间，然后5位datacenter标识位，</br>
* 5位机器ID（并不算标识符，实际是为线程标识），然后12位该毫秒内的当前毫秒内的计数，加起来刚好64位，为一个Long型。
* 0---0000000000 0000000000 0000000000 0000000000 0 --- 00000 ---00000 ---000000000000
* @author cailin
*
*/
public class IdWorker {
protected static final Logger LOG = LoggerFactory.getLogger(IdWorker.class);
//机器id
private long workerId;
//数据中心id
private long datacenterId;
private long sequence = 0L;
private long twepoch = 1288834974657L;
//机器标识位数
private long workerIdBits = 5L;
//数据中心标识位数
private long datacenterIdBits = 5L;
//机器ID最大值
private long maxWorkerId = -1L ^ (-1L << workerIdBits);
//数据中心ID最大值
private long maxDatacenterId = -1L ^ (-1L << datacenterIdBits);
//毫秒内自增位
private long sequenceBits = 12L;
//机器ID偏左移12位
private long workerIdShift = sequenceBits;
//数据中心ID左移17位
private long datacenterIdShift = sequenceBits + workerIdBits;
//时间毫秒左移22位
private long timestampLeftShift = sequenceBits + workerIdBits + datacenterIdBits;
private long sequenceMask = -1L ^ (-1L << sequenceBits);
private long lastTimestamp = -1L;
/**
* @param workerId 机器id
* @param datacenterId 数据中心id
*/
public IdWorker(long workerId, long datacenterId) {
// sanity check for workerId
if (workerId > maxWorkerId || workerId < 0) {
throw new IllegalArgumentException(String.format("worker Id can't be greater than %d or less than 0", maxWorkerId));
}
if (datacenterId > maxDatacenterId || datacenterId < 0) {
throw new IllegalArgumentException(String.format("datacenter Id can't be greater than %d or less than 0", maxDatacenterId));
}
this.workerId = workerId;
this.datacenterId = datacenterId;
LOG.info(String.format("worker starting. timestamp left shift %d, datacenter id bits %d, worker id bits %d, sequence bits %d, workerid %d", timestampLeftShift, datacenterIdBits, workerIdBits, sequenceBits, workerId));
}
public synchronized long nextId() {
long timestamp = timeGen();
if (timestamp < lastTimestamp) {
LOG.error(String.format("clock is moving backwards. Rejecting requests until %d.", lastTimestamp));
throw new RuntimeException(String.format("Clock moved backwards. Refusing to generate id for %d milliseconds", lastTimestamp - timestamp));
}
if (lastTimestamp == timestamp) {
//当前毫秒内，则+1
sequence = (sequence + 1) & sequenceMask;
if (sequence == 0) {
//当前毫秒内计数满了，则等待下一秒
timestamp = tilNextMillis(lastTimestamp);
}
} else {
sequence = 0L;
}
lastTimestamp = timestamp;
//ID偏移组合生成最终的ID，并返回ID
return ((timestamp - twepoch) << timestampLeftShift) | (datacenterId << datacenterIdShift) | (workerId << workerIdShift) | sequence;
}
protected long tilNextMillis(long lastTimestamp) {
long timestamp = timeGen();
while (timestamp <= lastTimestamp) {
timestamp = timeGen();
}
return timestamp;
}
protected long timeGen() {
return System.currentTimeMillis();
}
public static void main(String[] args) {
IdWorker worker = new IdWorker(1, 1);
worker.nextId();
}
}
PHP实现
<?php /* vim: set expandtab tabstop=4 shiftwidth=4: */ // +----------------------------------------------------------------------+ // | PHP version 5 | // +----------------------------------------------------------------------+ // | Copyright (c) 1997-2004 The PHP Group | // +----------------------------------------------------------------------+ // | This source file is subject to version 3.0 of the PHP license, | // | that is bundled with this package in the file LICENSE, and is | // | available through the world-wide-web at the following url: | // | http://www.php.net/license/3_0.txt. | // | If you did not receive a copy of the PHP license and are unable to | // | obtain it through the world-wide-web, please send a note to | // | [email protected] so we can mail you a copy immediately. | // +----------------------------------------------------------------------+ // | Authors: Original Author <[email protected]> | // | Your Name <[email protected]> | // +----------------------------------------------------------------------+ // // $Id:$ class Idwork { const debug = 1; static $workerId; static $twepoch = 1361775855078; static $sequence = 0; const workerIdBits = 4; static $maxWorkerId = 15; const sequenceBits = 10; static $workerIdShift = 10; static $timestampLeftShift = 14; static $sequenceMask = 1023; private static $lastTimestamp = - 1; function __construct($workId) { if ($workId > self::$maxWorkerId || $workId < 0) { throw new Exception("worker Id can't be greater than 15 or less than 0"); } self::$workerId = $workId; echo 'logdebug->__construct()->self::$workerId:' . self::$workerId; echo '</br>'; } function timeGen() { //获得当前时间戳 $time = explode(' ', microtime()); $time2 = substr($time[0], 2, 3); $timestramp = $time[1] . $time2; echo 'logdebug->timeGen()->$timestramp:' . $time[1] . $time2; echo '</br>'; return $time[1] . $time2; } function tilNextMillis($lastTimestamp) { $timestamp = $this->timeGen(); while ($timestamp <= $lastTimestamp) { $timestamp = $this->timeGen(); } echo 'logdebug->tilNextMillis()->$timestamp:' . $timestamp; echo '</br>'; return $timestamp; } function nextId() { $timestamp = $this->timeGen(); echo 'logdebug->nextId()->self::$lastTimestamp1:' . self::$lastTimestamp; echo '</br>'; if (self::$lastTimestamp == $timestamp) { self::$sequence = (self::$sequence + 1) & self::$sequenceMask; if (self::$sequence == 0) { echo "###########" . self::$sequenceMask; $timestamp = $this->tilNextMillis(self::$lastTimestamp); echo 'logdebug->nextId()->self::$lastTimestamp2:' . self::$lastTimestamp; echo '</br>'; } } else { self::$sequence = 0; echo 'logdebug->nextId()->self::$sequence:' . self::$sequence; echo '</br>'; } if ($timestamp < self::$lastTimestamp) { throw new Excwption("Clock moved backwards. Refusing to generate id for " . (self::$lastTimestamp - $timestamp) . " milliseconds"); } self::$lastTimestamp = $timestamp; echo 'logdebug->nextId()->self::$lastTimestamp3:' . self::$lastTimestamp; echo '</br>'; echo 'logdebug->nextId()->(($timestamp - self::$twepoch << self::$timestampLeftShift )):' . ((sprintf('%.0f', $timestamp) - sprintf('%.0f', self::$twepoch))); echo '</br>'; $nextId = ((sprintf('%.0f', $timestamp) - sprintf('%.0f', self::$twepoch))) | (self::$workerId << self::$workerIdShift) | self::$sequence; echo 'timestamp:' . $timestamp . '-----'; echo 'twepoch:' . sprintf('%.0f', self::$twepoch) . '-----'; echo 'timestampLeftShift =' . self::$timestampLeftShift . '-----'; echo 'nextId:' . $nextId . '----'; echo 'workId:' . self::$workerId . '-----'; echo 'workerIdShift:' . self::$workerIdShift . '-----'; return $nextId; } } $Idwork = new Idwork(1); $a = $Idwork->nextId(); $Idwork = new Idwork(2); $a = $Idwork->nextId(); ?>
压力测试结果，8g内存的笔记本，10w次请求1000线程
time:0:00:49.145 speed:4069589.9888086272
下面是压力测试的代码
package io.github.id;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.CountDownLatch;
import org.apache.commons.lang3.time.StopWatch;
public class Benchmark {
public static void main(String[] args) throws InterruptedException {
Benchmark benchmark = new Benchmark();
benchmark.test();
}
public void test() throws InterruptedException {
int threadCount = 2000;
final int genCount = 100000;
StopWatch watch = new StopWatch();
final IdWorker idWorker = new IdWorker(0, 0);
final CountDownLatch latch = new CountDownLatch(threadCount);
final Set<Long> set = new HashSet();
watch.start();
for (int i = 0; i < threadCount; ++i) {
Thread thread = new Thread() {
public void run() {
for (int j = 0; j < genCount; ++j) {
long id = idWorker.nextId();
}
latch.countDown();
}
};
thread.start();
}
latch.await();
watch.stop();
System.err.println("time:" + watch);
System.err.println("speed:" + genCount * threadCount / (watch.getTime() / 1000.0));
}
}