diff options
Diffstat (limited to 'inc/magpie/rss_cache.inc')
| -rw-r--r-- | inc/magpie/rss_cache.inc | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/inc/magpie/rss_cache.inc b/inc/magpie/rss_cache.inc new file mode 100644 index 000000000..5b4e37db3 --- /dev/null +++ b/inc/magpie/rss_cache.inc @@ -0,0 +1,184 @@ +<?php +/* + * Project: MagpieRSS: a simple RSS integration tool + * File: rss_cache.inc, a simple, rolling(no GC), cache + * for RSS objects, keyed on URL. + * Author: Kellan Elliott-McCrea <kellan@protest.net> + * Version: 0.51 + * License: GPL + * + * The lastest version of MagpieRSS can be obtained from: + * http://magpierss.sourceforge.net + * + * For questions, help, comments, discussion, etc., please join the + * Magpie mailing list: + * http://lists.sourceforge.net/lists/listinfo/magpierss-general + * + */ + +class RSSCache { + var $BASE_CACHE = './cache'; // where the cache files are stored + var $MAX_AGE = 3600; // when are files stale, default one hour + var $ERROR = ""; // accumulate error messages + + function RSSCache ($base='', $age='') { + if ( $base ) { + $this->BASE_CACHE = $base; + } + if ( $age ) { + $this->MAX_AGE = $age; + } + + // attempt to make the cache directory + if ( ! @file_exists( $this->BASE_CACHE ) ) { + $status = @mkdir( $this->BASE_CACHE, 0755 ); + + // if make failed + if ( ! $status ) { + $this->error( + "Cache couldn't make dir '" . $this->BASE_CACHE . "'." + ); + } + } + } + +/*=======================================================================*\ + Function: set + Purpose: add an item to the cache, keyed on url + Input: url from wich the rss file was fetched + Output: true on sucess +\*=======================================================================*/ + function set ($url, $rss) { + $this->ERROR = ""; + $cache_file = $this->file_name( $url ); + $fp = @fopen( $cache_file, 'w' ); + + if ( ! $fp ) { + $this->error( + "Cache unable to open file for writing: $cache_file" + ); + return 0; + } + + + $data = $this->serialize( $rss ); + fwrite( $fp, $data ); + fclose( $fp ); + + return $cache_file; + } + +/*=======================================================================*\ + Function: get + Purpose: fetch an item from the cache + Input: url from wich the rss file was fetched + Output: cached object on HIT, false on MISS +\*=======================================================================*/ + function get ($url) { + $this->ERROR = ""; + $cache_file = $this->file_name( $url ); + + if ( ! @file_exists( $cache_file ) ) { + $this->debug( + "Cache doesn't contain: $url (cache file: $cache_file)" + ); + return 0; + } + + $fp = @fopen($cache_file, 'r'); + if ( ! $fp ) { + $this->error( + "Failed to open cache file for reading: $cache_file" + ); + return 0; + } + + $data = fread( $fp, filesize($cache_file) ); + $rss = $this->unserialize( $data ); + + return $rss; + } + +/*=======================================================================*\ + Function: check_cache + Purpose: check a url for membership in the cache + and whether the object is older then MAX_AGE (ie. STALE) + Input: url from wich the rss file was fetched + Output: cached object on HIT, false on MISS +\*=======================================================================*/ + function check_cache ( $url ) { + $this->ERROR = ""; + $filename = $this->file_name( $url ); + + if ( @file_exists( $filename ) ) { + // find how long ago the file was added to the cache + // and whether that is longer then MAX_AGE + $mtime = filemtime( $filename ); + $age = time() - $mtime; + if ( $this->MAX_AGE > $age ) { + // object exists and is current + return 'HIT'; + } + else { + // object exists but is old + return 'STALE'; + } + } + else { + // object does not exist + return 'MISS'; + } + } + +/*=======================================================================*\ + Function: serialize +\*=======================================================================*/ + function serialize ( $rss ) { + return serialize( $rss ); + } + +/*=======================================================================*\ + Function: unserialize +\*=======================================================================*/ + function unserialize ( $data ) { + return unserialize( $data ); + } + +/*=======================================================================*\ + Function: file_name + Purpose: map url to location in cache + Input: url from wich the rss file was fetched + Output: a file name +\*=======================================================================*/ + function file_name ($url) { + $filename = md5( $url ); + return join( DIRECTORY_SEPARATOR, array( $this->BASE_CACHE, $filename ) ); + } + +/*=======================================================================*\ + Function: error + Purpose: register error +\*=======================================================================*/ + function error ($errormsg, $lvl=E_USER_WARNING) { + // append PHP's error message if track_errors enabled + if ( isset($php_errormsg) ) { + $errormsg .= " ($php_errormsg)"; + } + $this->ERROR = $errormsg; + if ( MAGPIE_DEBUG ) { + trigger_error( $errormsg, $lvl); + } + else { + error_log( $errormsg, 0); + } + } + + function debug ($debugmsg, $lvl=E_USER_NOTICE) { + if ( MAGPIE_DEBUG ) { + $this->error("MagpieRSS [debug] $debugmsg", $lvl); + } + } + +} + +?> |