<?php

// comment this line out if on windows 9x or any other os not supporting flock()
define("WITH_FLOCK", 1);    

/*************************************************

morecache.php - a general-purpose script-output caching class

home page: www.samscripts.com/scripts/morecache
support: support.samscripts.com/index.php

licence: freeware / optionally giftware ( www.samscripts.com/donate.php )
author: Sam Yapp
date: 8th September 2002

documentation and examples at www.samscripts.com

*************************************************/

class morecache{

    var $expireafter;
    var $expiretype;
    var $filenames;
    var $searchvars;
    var $replacevars;
    var $activecaches = -1;
    var $cachepath = "./cached";


    function setexpiry($expireafter = 60){    
        $this->expireafter = $expireafter;
        if( is_int($expireafter) ){
            $this->expiretype = "sec";
        }else{
            $this->expiretype = "date";
        }
    }

    function morecache( $cachepath = "", $expireafter = 3600){
        if( $cachepath != "" ) $this->cachepath = $cachepath;
        $this->setexpiry($expireafter);
        $this->filenames = array();
        $this->searchvars = array();
        $this->replacevars = array();
        $this->activecaches = -1;
    }


    function makecachename($id){
        return $this->cachepath."/".md5($id).".cache";
    }

    function expirecache($cachename){
        $filename = $this->makecachename($cachename);
        @unlink($filename);
    }

    function cache($cachename, $expireafter = "", $search = array(), $replace=array()){
        if( !is_array($search) ) $search = array($search);
        $this->activecaches++;

        $this->filenames[$this->activecaches] = $this->makecachename($cachename);
        $this->searches[$this->activecaches] = &$search;
        $this->replaces[$this->activecaches] = &$replace;

        if( $expireafter == "" ) $expireafter = $this->expireafter;
        $this->setexpiry($expireafter);

        $update = 0;
        if( !file_exists($this->filenames[$this->activecaches]) ){
            $update = 1;
            $exist = 0;
        }else{
            $exist = 1;
            $updated = filemtime($this->filenames[$this->activecaches]);
        }

        if( $exist ==0 || $updated < ($this->expiretype == "sec" ? time() - $this->expireafter : strtotime($this->expireafter))){
            $update = 1;
        }

        if( $update){ 
            ob_start();
            return true;
        }else{
            if( count($this->searches[$this->activecaches]) == 0 ){
                $fp = $this->flock($this->filenames[$this->activecaches], "r");
                if(!@readfile( $this->filenames[$this->activecaches])) $this->error = "readfile failed for ".$this->filenames[$this->activecaches];
                $this->funlock($fp);
            }else{
                $f = join("", file($this->filenames[$this->activecaches]));
                echo str_replace($this->searches[$this->activecaches], $this->replaces[$this->activecaches], $f);
            }
            return false;
        }
    }

    function stop($returnbuffer = false, $showoutput = true){        // if returnbuffer is true, returns the contents of the cache to the calling script
        $this->cachecontents = ob_get_contents();
        $this->save();
        if( $showoutput == true && count( $this->searches[$this->activecaches]) != 0 ){
            ob_end_clean();
            echo str_replace($this->searches[$this->activecaches], $this->replaces[$this->activecaches], $this->cachecontents);
        }elseif( $showoutput == true ){
            ob_end_flush();
        }else{
            ob_end_clean();
        }
        $this->activecaches--;
        return ($showoutput == true ? $this->cachecontents : true);
    }

    function flock($filename, $mode){
        $fp = @fopen($filename, $mode = "r" ? "r" : "wb");
        if( defined(WITH_FLOCK) ) flock($fp, $mode="r" ? LOCK_SH : LOCK_EX);
        ignore_user_abort(true);
        return $fp;
    }

    function funlock($fp){
        if( $fp ){
            flock($fp, LOCK_UN);
            @fclose($fp);
        }
    }

    function save(){
        $fo = $this->flock($this->filenames[$this->activecaches], "w");
        if( $fo ){
            if( !@fwrite( $fo, $this->cachecontents)) $this->error = "Error writing to file ".$this->filenames[$this->activecaches];
            $this->funlock($fo);
        }else{
            $this->error = "Failed opening file ".$this->filenames[$this->activecaches]." for output.";
        }
    }

}

?>