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Diffstat (limited to 'app/lib/Cache.php')
| -rw-r--r-- | app/lib/Cache.php | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/app/lib/Cache.php b/app/lib/Cache.php new file mode 100644 index 0000000..9425de3 --- /dev/null +++ b/app/lib/Cache.php @@ -0,0 +1,254 @@ +<?php +/**
+* This library is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation; either version 2 of the License, or
+* (at your option) any later version.
+*
+* This library is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this software; if not, write to the Free Software
+* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+*
+* © Copyright 2005 Richard Heyes
+*/ + +/** +* Caching Libraries for PHP5 +* +* Handles data and output caching. Defaults to /dev/shm +* (shared memory). All methods are static. +* +* Eg: (output caching) +* +* if (!OutputCache::Start('group', 'unique id', 600)) { +* +* // ... Output +* +* OutputCache::End(); +* } +* +* Eg: (data caching) +* +* if (!$data = DataCache::Get('group', 'unique id')) { +* +* $data = time(); +* +* DataCache::Put('group', 'unique id', 10, $data); +* } +* +* echo $data; +*/ + class Cache + { + /** + * Whether caching is enabled + * @var bool + */ + public static $enabled = true; + + /** + * Place to store the cache files + * @var string + */ + protected static $store = '/dev/shm/'; + + /** + * Prefix to use on cache files + * @var string + */ + protected static $prefix = 'cache_'; + + /** + * Stores data + * + * @param string $group Group to store data under + * @param string $id Unique ID of this data + * @param int $ttl How long to cache for (in seconds) + */ + protected static function write($group, $id, $ttl, $data) + { + $filename = self::getFilename($group, $id); + + if (self::$enabled && $fp = fopen($filename, 'xb')) { + + if (flock($fp, LOCK_EX)) { + fwrite($fp, $data); + } + fclose($fp); + + // Set filemtime + touch($filename, time() + $ttl); + } + } + + /** + * Reads data + * + * @param string $group Group to store data under + * @param string $id Unique ID of this data + */ + protected static function read($group, $id) + { + $filename = self::getFilename($group, $id); + + return file_get_contents($filename); + } + + /** + * Determines if an entry is cached + * + * @param string $group Group to store data under + * @param string $id Unique ID of this data + */ + protected static function isCached($group, $id) + { + $filename = self::getFilename($group, $id); + + if (self::$enabled && file_exists($filename) && filemtime($filename) > time()) { + return true; + } + + @unlink($filename); + + return false; + } + + /** + * Builds a filename/path from group, id and + * store. + * + * @param string $group Group to store data under + * @param string $id Unique ID of this data + */ + protected static function getFilename($group, $id) + { + $id = md5($id); + + return self::$store . self::$prefix . "{$group}_{$id}"; + } + + /** + * Sets the filename prefix to use + * + * @param string $prefix Filename Prefix to use + */ + public static function setPrefix($prefix) + { + self::$prefix = $prefix; + } + + /** + * Sets the store for cache files. Defaults to + * /dev/shm. Must have trailing slash. + * + * @param string $store The dir to store the cache data in + */ + public static function setStore($store) + { + self::$store = $store; + } + } + + /** + * Output Cache extension of base caching class + */ + class OutputCache extends Cache + { + /** + * Group of currently being recorded data + * @var string + */ + private static $group; + + /** + * ID of currently being recorded data + * @var string + */ + private static $id; + + /** + * Ttl of currently being recorded data + * @var int + */ + private static $ttl; + + /** + * Starts caching off. Returns true if cached, and dumps + * the output. False if not cached and start output buffering. + * + * @param string $group Group to store data under + * @param string $id Unique ID of this data + * @param int $ttl How long to cache for (in seconds) + * @return bool True if cached, false if not + */ + public static function Start($group, $id, $ttl) + { + if (self::isCached($group, $id)) { + echo self::read($group, $id); + return true; + + } else { + + ob_start(); + + self::$group = $group; + self::$id = $id; + self::$ttl = $ttl; + + return false; + } + } + + /** + * Ends caching. Writes data to disk. + */ + public static function End() + { + $data = ob_get_contents(); + ob_end_flush(); + + self::write(self::$group, self::$id, self::$ttl, $data); + } + } + + /** + * Data cache extension of base caching class + */ + class DataCache extends Cache + { + + /** + * Retrieves data from the cache + * + * @param string $group Group this data belongs to + * @param string $id Unique ID of the data + * @return mixed Either the resulting data, or null + */ + public static function Get($group, $id) + { + if (self::isCached($group, $id)) { + return unserialize(self::read($group, $id)); + } + + return null; + } + + /** + * Stores data in the cache + * + * @param string $group Group this data belongs to + * @param string $id Unique ID of the data + * @param int $ttl How long to cache for (in seconds) + * @param mixed $data The data to store + */ + public static function Put($group, $id, $ttl, $data) + { + self::write($group, $id, $ttl, serialize($data)); + } + } +?>
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