File: selfcacher.class.php

<?php
/*
  self cacher v 1.0.1
  need PHP v4.0.6 or above

  by Hisun Yang  (a Chinese)
  @ 2002.01.09
  yanghisun@english88.com.cn  (accepts any questions )

  caution: can't cache posted page

  //run these command in linux

  mkdir /tmp/cache
  chown nobody:nobody cache
  chmod 700 cache

  //do these in windows

  create a folder 'D:/Apache/tmp/cache' (your cached files will be there)


*/
function _self_cacher_getmicrotime(){
         list($usec, $sec) = explode(" ",microtime());
         return ((float)$usec + (float)$sec);
}
class TSelfCacher{
      var $_log_performance=FALSE;
      var $_log_full_filename;
      var $_start_time;
      //
      var $_cache_to_dir="/tmp/cache/";     //linux
      //var $_cache_to_dir="D:/Apache/tmp/cache";  //windows  ,you must create this folder yourself
      var $_cached_filename;
      var $_cached_full_filename;
      var $_cached_content;
      //
      //constructor
      function TSelfCacher($ALogPerformance=FALSE){
               //if $ALogPerformance ,enable performance log
               $this->_log_performance=$ALogPerformance?TRUE:FALSE;
               if($this->_log_performance) $this->_start_time=_self_cacher_getmicrotime();
               global $HTTP_SERVER_VARS;
               if($HTTP_SERVER_VARS["REQUEST_METHOD"]=="POST") return; //don't cache posted file
               $this->setCacheFileAndDir();
               $this->existOrMakeToDir();
               if($this->getCachedContent()){
                  $this->show();
               }else{
                $this->startCache();
                return $this;
               }
      }
      function setCacheFileAndDir(){
               global $HTTP_SERVER_VARS;
               $this->_cached_filename=md5($HTTP_SERVER_VARS["REQUEST_URI"]).".cache";
               $this->_cache_to_dir.="/".$HTTP_SERVER_VARS["SERVER_NAME"].'_'.date("Ymd");
               $this->_cached_full_filename=$this->_cache_to_dir."/".$this->_cached_filename;
               if($this->_log_performance){$this->_log_full_filename=$this->_cache_to_dir."/performance.log";}
      }
      function getCachedContent(){        //return true when get cached content before ,or return false
               if(!file_exists($this->_cached_full_filename)){ return FALSE;}
               if($fp=@fopen($this->_cached_full_filename,"r")){
                     flock($fp,LOCK_SH);
                     $this->_cached_content=fread($fp,filesize($this->_cached_full_filename));
                     flock($fp,LOCK_UN);
                     fclose($fp);
                     return TRUE;
               }else{
                   return FALSE;
               }
      }
      function setCachedContent(&$AContent){   //call function by ref can speed up
               $this->_cached_content=$AContent;
      }
      function writeCachedContent(){
               if($fp=@fopen($this->_cached_full_filename,"w")){
                     flock($fp,LOCK_EX);
                     fwrite($fp,$this->_cached_content);
                     flock($fp,LOCK_UN);
                     fclose($fp);
                     if($this->_log_performance){
                        $this->logToFile();
                     }
                     return TRUE;
               }else{
                   return FALSE;
               }
      }
      function logToFile(){
               $_spent_time=_self_cacher_getmicrotime()-$this->_start_time;
               if($fp=@fopen($this->_log_full_filename,"a")){
                     flock($fp,LOCK_EX);
                     fputs($fp,date("[Y-m-d H:i:s]").$this->_cached_full_filename."  ".$_spent_time." microseconds\n");
                     flock($fp,LOCK_UN);
                     fclose($fp);
                     return TRUE;
               }else{
                   return FALSE;
               }
      }
      function startCache(){
               ob_start("_cacher_call_back");
      }
      function existOrMakeToDir(){      //return true if is dir ,or make it
               if(is_dir($this->_cache_to_dir)){
                   return TRUE;
               }
               else{
                   return @mkdir($this->_cache_to_dir,0700);
               }
      }
      function show(){
               echo $this->_cached_content;
               if($this->_log_performance){
                  $this->logToFile();
               }
               exit();
      }
      function flush(){
               ob_end_flush();
      }
}
function _cacher_call_back(&$AContent){
         global $_SELF_CACHER;
         $_SELF_CACHER->setCachedContent($AContent);
         $_SELF_CACHER->writeCachedContent();
         return $_SELF_CACHER->_cached_content;
}
if(!isset($_SELF_CACHER))$_SELF_CACHER=&new TSelfCacher;
//CAUTION: the name _SELF_CACHER can't be modified
?>