<?php
class cache{
public $dirName = 'cachedir';


function getCacheFile($name,$dirName=''){
	$self_path = dirname(__FILE__);
	$cfile=$self_path."/".($dirName?$dirName:$this->dirName)."/".md5($name);
	return $cfile;
}

function openCacheFile($name){
	$file = $this->getCacheFile($name);
	return fopen($file, 'a+');
}
function readCache($name){
	$fhandle = $this->openCacheFile($name);
	
	$ret = $this->getCache($name,$fhandle);
	$this->freeCache($fhandle,false);
	return $ret;
}

function writeCache($name,$data,$cache_time=-1){
	$fhandle = $this->openCacheFile($name);
	$ret = $this->setCache($name, $data, $cache_time, $fhandle);
	$this->freeCache($fhandle,false);
	return $ret;
}

function getCache($name, $fhandle){
	$cfile=$this->getCacheFile($name);
	clearstatcache();
	if(file_exists($cfile)){
			fseek($fhandle,0);//新增
			$c = @fread($fhandle, filesize($cfile));
			if($c){
				$cls = explode('__$$$__',$c);
				if(isset($cls[1])&& is_numeric($cls[1])){
					if(($cls[1]-time())>-1){
						return $cls[0];
					}
				}
			}
	}
}

function freeCacheLock($fhandle,$lock_ret){
	if($lock_ret)
	{
		@flock($fhandle, LOCK_UN);
	}
}

function freeCache($fhandle,$lock_ret){
	if($lock_ret)
	{
		@flock($fhandle, LOCK_UN);
	}
	@fclose($fhandle);
}


function setCache($name, $data, $cache_time, $fhandle){
	$cfile=$this->getCacheFile($name);
	ftruncate($fhandle,0);
	if($data && $cache_time>-1){
		$datav = $data.'__$$$__'.(time()+$cache_time);
		fwrite($fhandle, $datav); 
	}
	//@file_put_contents($cfile,$data);
	return $data;
}

function existCache($name){
	$cfile=$this->getCacheFile($name);
	return file_exists($cfile);
}
}
?>