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Diffstat (limited to '')
| -rw-r--r-- | include/cache.class.php | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/include/cache.class.php b/include/cache.class.php new file mode 100644 index 000000000..b1f7dde89 --- /dev/null +++ b/include/cache.class.php @@ -0,0 +1,143 @@ +<?php +// +-----------------------------------------------------------------------+ +// | Piwigo - a PHP based photo gallery | +// +-----------------------------------------------------------------------+ +// | Copyright(C) 2008-2014 Piwigo Team http://piwigo.org | +// | Copyright(C) 2003-2008 PhpWebGallery Team http://phpwebgallery.net | +// | Copyright(C) 2002-2003 Pierrick LE GALL http://le-gall.net/pierrick | +// +-----------------------------------------------------------------------+ +// | This program 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 | +// | | +// | This program 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 program; if not, write to the Free Software | +// | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, | +// | USA. | +// +-----------------------------------------------------------------------+ + +/** + Provides a persistent cache mechanism across multiple page loads/sessions etc... +*/ +abstract class PersistentCache +{ + var $default_lifetime = 86400; + protected $instance_key = PHPWG_VERSION; + + /** + @return a key that can be safely be used with get/set methods + */ + function make_key($key) + { + if ( is_array($key) ) + { + $key = implode('&', $key); + } + $key .= $this->instance_key; + return md5($key); + } + + /** + Searches for a key in the persistent cache and fills corresponding value. + @param string $key + @param out mixed $value + @return false if the $key is not found in cache ($value is not modified in this case) + */ + abstract function get($key, &$value); + + /** + Sets a key/value pair in the persistent cache. + @param string $key - it should be the return value of make_key function + @param mixed $value + @param int $lifetime + @return false on error + */ + abstract function set($key, $value, $lifetime=null); + + /** + Purge the persistent cache. + @param boolean $all - if false only expired items will be purged + */ + abstract function purge($all); +} + + +/** + Implementation of a persistent cache using files. +*/ +class PersistentFileCache extends PersistentCache +{ + private $dir; + + function __construct() + { + global $conf; + $this->dir = PHPWG_ROOT_PATH.$conf['data_location'].'cache/'; + } + + function get($key, &$value) + { + $loaded = @file_get_contents($this->dir.$key.'.cache'); + if ($loaded !== false && ($loaded=unserialize($loaded)) !== false) + { + if ($loaded['expire'] > time()) + { + $value = $loaded['data']; + return true; + } + } + return false; + } + + function set($key, $value, $lifetime=null) + { + if ($lifetime === null) + { + $lifetime = $this->default_lifetime; + } + + if (rand() % 199 == 0) + { + $this->purge(false); + } + + $serialized = serialize( array( + 'expire' => time() + $lifetime, + 'data' => $value + )); + + if (false === @file_put_contents($this->dir.$key.'.cache', $serialized)) + { + mkgetdir($this->dir, MKGETDIR_DEFAULT&~MKGETDIR_DIE_ON_ERROR); + if (false === @file_put_contents($this->dir.$key.'.cache', $serialized)) + { + return false; + } + } + return true; + } + + function purge($all) + { + $files = glob($this->dir.'*.cache'); + if (empty($files)) + { + return; + } + + $limit = time() - $this->default_lifetime; + foreach ($files as $file) + { + if ($all || @filemtime($file) < $limit) + @unlink($file); + } + } + +} + +?>
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