<?php
class Cache {/** 缓存目录 **/var $CacheDir        = './cache';/** 缓存的文件 **/var $CacheFile        = '';/** 文件缓存时间(分钟) **/var $CacheTime        = 0;/** 文件是否已缓存 **/var $CacheFound        = False;/** 错误及调试信息 **/var $DebugMsg        = NULL;function Cache($CacheTime = 0) {$this->CacheTime    = $CacheTime;}private function Run() {/** 缓存时间大于0,检测缓存文件的修改时间,在缓存时间内为缓存文件名,超过缓存时间为False，小于等于0,返回false,并清理已缓存的文件 **/Return $this->CacheTime ? $this->CheckCacheFile() : $this->CleanCacheFile();}function GetCache($VistUrl,$CacheFileType = 'html'){$this->SetCacheFile($VistUrl,$CacheFileType);$fileName=$this->CheckCacheFile();if($fileName){$fp = fopen($fileName,"r");$content_= fread($fp, filesize($fileName));fclose($fp);return $content_;}else{return false;}}private function SetCacheFile($VistUrl,$CacheFileType = 'html') {if(empty($VistUrl)) {/** 默认为index.html **/$this->CacheFile = 'index';}else {/** 传递参数为$_POST时 **/$this->CacheFile = is_array($VistUrl) ? implode('.',$VistUrl) : $VistUrl;}$this->CacheFile = $this->CacheDir.'/'.md5($this->CacheFile);$this->CacheFile.= '.'.$CacheFileType;}function SetCacheTime($t = 60) {$this->CacheTime = $t;}private function CheckCacheFile() {if(!$this->CacheTime || !file_exists($this->CacheFile)) {Return False;}/** 比较文件的建立/修改日期和当前日期的时间差 **/$GetTime=(Time()-Filemtime($this->CacheFile))/(60*1);/** Filemtime函数有缓存,注意清理 **/Clearstatcache();$this->Debug('Time Limit '.($GetTime*60).'/'.($this->CacheTime*60).'');$this->CacheFound = $GetTime <= $this->CacheTime ? $this->CacheFile : False;Return $this->CacheFound;}function SaveToCacheFile($VistUrl,$Content,$CacheFileType = 'html') {$this->SetCacheFile($VistUrl,$CacheFileType);if(!$this->CacheTime) {Return False;}/** 检测缓存目录是否存在 **/if(true === $this->CheckCacheDir()) {$CacheFile = $this->CacheFile;$CacheFile = str_replace('//','/',$CacheFile);$fp = @fopen($CacheFile,"wb");if(!$fp) {$this->Debug('Open File '.$CacheFile.' Fail');}else {if(@!fwrite($fp,$Content)){$this->Debug('Write '.$CacheFile.' Fail');}else {$this->Debug('Cached File');};@fclose($fp);}}else {/** 缓存目录不存在，或不能建立目录 **/$this->Debug('Cache Folder '.$this->CacheDir.' Not Found');}}private function CheckCacheDir() {if(file_exists($this->CacheDir)) { Return true; }/** 保存当前工作目录 **/$Location = getcwd();/** 把路径划分成单个目录 **/$Dir = split("/", $this->CacheDir);/** 循环建立目录 **/$CatchErr = True;for ($i=0; $i<count($Dir); $i++){if (!file_exists($Dir[$i])){/** 建立目录失败会返回False 返回建立最后一个目录的返回值 **/$CatchErr = @mkdir($Dir[$i],0777);}@chdir($Dir[$i]);}/** 建立完成后要切换到原目录 **/chdir($Location);if(!$CatchErr) {$this->Debug('Create Folder '.$this->CacheDir.' Fail');}Return $CatchErr;}private function CleanCacheFile() {if(file_exists($this->CacheFile)) {@chmod($this->CacheFile,777);@unlink($this->CacheFile);}/** 置没有缓存文件 **/$this->CacheFound = False;Return $this->CacheFound;}function Debug($msg='') {if(DEBUG) {$this->DebugMsg[] = '[Cache]'.$msg;}}function GetError() {Return empty($this->DebugMsg) ? '' : "<br>n".implode("<br>n",$this->DebugMsg);}
}/* end of class */
?>