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-rw-r--r--include/cache.class.php143
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);
+ }
+ }
+
+}
+
+?> \ No newline at end of file