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770 florian 1
<?php
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/*
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 * Project:     MagpieRSS: a simple RSS integration tool
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 * File:        rss_cache.inc, a simple, rolling(no GC), cache
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 *              for RSS objects, keyed on URL.
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 * Author:      Kellan Elliott-McCrea <kellan@protest.net>
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 * Version:     0.51
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 * License:     GPL
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 *
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 * The lastest version of MagpieRSS can be obtained from:
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 * http://magpierss.sourceforge.net
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 *
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 * For questions, help, comments, discussion, etc., please join the
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 * Magpie mailing list:
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 * http://lists.sourceforge.net/lists/listinfo/magpierss-general
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 *
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 */
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class RSSCache {
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    var $BASE_CACHE = './cache';    // where the cache files are stored
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    var $MAX_AGE    = 3600;         // when are files stale, default one hour
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    var $ERROR      = "";           // accumulate error messages
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    function RSSCache ($base='', $age='') {
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        if ( $base ) {
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            $this->BASE_CACHE = $base;
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        }
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        if ( $age ) {
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            $this->MAX_AGE = $age;
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        }
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        // attempt to make the cache directory
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        if ( ! file_exists( $this->BASE_CACHE ) ) {
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            $status = @mkdir( $this->BASE_CACHE, 0755 );
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            // if make failed
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            if ( ! $status ) {
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                $this->error(
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                    "Cache couldn't make dir '" . $this->BASE_CACHE . "'."
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                );
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            }
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        }
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    }
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/*=======================================================================*\
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    Function:   set
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    Purpose:    add an item to the cache, keyed on url
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    Input:      url from wich the rss file was fetched
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    Output:     true on sucess
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\*=======================================================================*/
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    function set ($url, $rss) {
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        $this->ERROR = "";
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        $cache_file = $this->file_name( $url );
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        $fp = @fopen( $cache_file, 'w' );
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        if ( ! $fp ) {
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            $this->error(
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                "Cache unable to open file for writing: $cache_file"
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            );
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            return 0;
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        }
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        $data = $this->serialize( $rss );
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        fwrite( $fp, $data );
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        fclose( $fp );
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        return $cache_file;
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    }
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/*=======================================================================*\
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    Function:   get
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    Purpose:    fetch an item from the cache
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    Input:      url from wich the rss file was fetched
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    Output:     cached object on HIT, false on MISS
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\*=======================================================================*/
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    function get ($url) {
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        $this->ERROR = "";
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        $cache_file = $this->file_name( $url );
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        if ( ! file_exists( $cache_file ) ) {
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            $this->debug(
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                "Cache doesn't contain: $url (cache file: $cache_file)"
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            );
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            return 0;
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        }
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        $fp = @fopen($cache_file, 'r');
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        if ( ! $fp ) {
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            $this->error(
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                "Failed to open cache file for reading: $cache_file"
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            );
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            return 0;
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        }
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        if ($filesize = filesize($cache_file) ) {
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        	$data = fread( $fp, filesize($cache_file) );
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        	$rss = $this->unserialize( $data );
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        	return $rss;
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    	}
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    	return 0;
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    }
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/*=======================================================================*\
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    Function:   check_cache
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    Purpose:    check a url for membership in the cache
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                and whether the object is older then MAX_AGE (ie. STALE)
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    Input:      url from wich the rss file was fetched
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    Output:     cached object on HIT, false on MISS
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\*=======================================================================*/
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    function check_cache ( $url ) {
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        $this->ERROR = "";
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        $filename = $this->file_name( $url );
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        if ( file_exists( $filename ) ) {
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            // find how long ago the file was added to the cache
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            // and whether that is longer then MAX_AGE
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            $mtime = filemtime( $filename );
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            $age = time() - $mtime;
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            if ( $this->MAX_AGE > $age ) {
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                // object exists and is current
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                return 'HIT';
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            }
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            else {
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                // object exists but is old
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                return 'STALE';
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            }
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        }
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        else {
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            // object does not exist
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            return 'MISS';
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        }
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    }
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	function cache_age( $cache_key ) {
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		$filename = $this->file_name( $url );
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		if ( file_exists( $filename ) ) {
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			$mtime = filemtime( $filename );
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            $age = time() - $mtime;
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			return $age;
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		}
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		else {
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			return -1;
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		}
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	}
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/*=======================================================================*\
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    Function:   serialize
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\*=======================================================================*/
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    function serialize ( $rss ) {
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        return serialize( $rss );
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    }
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/*=======================================================================*\
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    Function:   unserialize
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\*=======================================================================*/
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    function unserialize ( $data ) {
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        return unserialize( $data );
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    }
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/*=======================================================================*\
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    Function:   file_name
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    Purpose:    map url to location in cache
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    Input:      url from wich the rss file was fetched
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    Output:     a file name
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\*=======================================================================*/
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    function file_name ($url) {
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        $filename = md5( $url );
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        return join( DIRECTORY_SEPARATOR, array( $this->BASE_CACHE, $filename ) );
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    }
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/*=======================================================================*\
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    Function:   error
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    Purpose:    register error
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\*=======================================================================*/
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    function error ($errormsg, $lvl=E_USER_WARNING) {
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        // append PHP's error message if track_errors enabled
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        if ( isset($php_errormsg) ) {
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            $errormsg .= " ($php_errormsg)";
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        }
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        $this->ERROR = $errormsg;
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        if ( MAGPIE_DEBUG ) {
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            trigger_error( $errormsg, $lvl);
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        }
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        else {
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            error_log( $errormsg, 0);
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        }
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    }
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    function debug ($debugmsg, $lvl=E_USER_NOTICE) {
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        if ( MAGPIE_DEBUG ) {
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            $this->error("MagpieRSS [debug] $debugmsg", $lvl);
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        }
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    }
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}
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?>