<?php
// 三段
// 一段是微秒 一段是地址 一段是随机数
class uuid
{
	private $valueBeforeMD5;
	private $valueAfterMD5;

	function __construct()
	{
		$address = $this->getLocalHost();
		$this->valueBeforeMD5 = $address.':'.$this->currentTimeMillis().':'.$this->nextLong();
		$this->valueAfterMD5 = md5($this->valueBeforeMD5);
	}
	function toString()
	{
		$raw = strtoupper($this->valueAfterMD5);
		return substr($raw,0,8).'-'.substr($raw,8,4).'-'.substr($raw,12,4).'-'.substr($raw,16,4).'-'.substr($raw,20);
	}

	private function nextLong()
	{
		$tmp = rand(0,1)?'-':'';
		return $tmp.rand(1000, 9999).rand(1000, 9999).rand(1000, 9999).rand(100, 999).rand(100, 999);
	}
	private function currentTimeMillis()
	{
		list($usec, $sec) = explode(" ",microtime());
		return $sec.substr($usec, 2, 3);
	}
	private function getLocalHost()
	{
		$address = $_ENV["COMPUTERNAME"].'/';
		$address.= $_SERVER["SERVER_ADDR"];
		return strtolower($address);
	}	
}
?>