+++ /dev/null
-<?php
-// +----------------------------------------------------------------------+
-// | PHP Version 4 |
-// +----------------------------------------------------------------------+
-// | Copyright (c) 1997, 1998, 1999, 2000, 2001 The PHP Group |
-// +----------------------------------------------------------------------+
-// | This source file is subject to version 2.0 of the PHP license, |
-// | that is bundled with this package in the file LICENSE, and is |
-// | available at through the world-wide-web at |
-// | http://www.php.net/license/2_02.txt. |
-// | If you did not receive a copy of the PHP license and are unable to |
-// | obtain it through the world-wide-web, please send a note to |
-// | license@php.net so we can mail you a copy immediately. |
-// +----------------------------------------------------------------------+
-// | Authors: Ulf Wendel <ulf.wendel@phpdoc.de> |
-// | Sebastian Bergmann <sb@sebastian-bergmann.de> |
-// +----------------------------------------------------------------------+
-//
-// $Id$
-
-require_once('PEAR.php');
-require_once('Cache/Error.php');
-
-/**
-* Cache is a base class for cache implementations.
-*
-* The pear cache module is a generic data cache which can be used to
-* cache script runs. The idea behind the cache is quite simple. If you have
-* the same input parameters for whatever tasks/algorithm you use you'll
-* usually get the same output. So why not caching templates, functions calls,
-* graphic generation etc. Caching certain actions e.g. XSLT tranformations
-* saves you lots of time.
-*
-* The design of the cache reminds of PHPLibs session implementation. A
-* (PHPLib: session) controller uses storage container (PHPLib: ct_*.inc) to save
-* certain data (PHPLib: session data). In contrast to the session stuff it's up to
-* you to generate an ID for the data to cache. If you're using the output cache
-* you might use the script name as a seed for cache::generateID(), if your using the
-* function cache you'd use an array with all function parameters.
-*
-* Usage example of the generic data cache:
-*
-* require_once('Cache.php');
-*
-* $cache = new Cache('file', array('cache_dir' => 'cache/') );
-* $id = $cache->generateID('testentry');
-*
-* if ($data = $cache->get($id)) {
-* print "Cache hit.<br>Data: $data";
-*
-* } else {
-* $data = 'data of any kind';
-* $cache->save($id, $data);
-* print 'Cache miss.<br>';
-* }
-*
-* WARNING: No File/DB-Table-Row locking is implemented yet,
-* it's possible, that you get corrupted data-entries under
-* bad circumstances (especially with the file container)
-*
-* @author Ulf Wendel <ulf.wendel@phpdoc.de>
-* @version $Id$
-* @package Cache
-* @access public
-*/
-class Cache extends PEAR {
-
- /**
- * Enables / disables caching.
- *
- * TODO: Add explanation what this is good for.
- *
- * @var boolean
- * @access private
- */
- var $caching = true;
-
- /**
- * Garbage collection: probability in seconds
- *
- * If set to a value above 0 a garbage collection will
- * flush all cache entries older than the specified number
- * of seconds.
- *
- * @var integer
- * @see $gc_probability, $gc_maxlifetime
- * @access public
- */
- var $gc_time = 1;
-
- /**
- * Garbage collection: probability in percent
- *
- * TODO: Add an explanation.
- *
- * @var integer 0 => never
- * @see $gc_time, $gc_maxlifetime
- * @access public
- */
- var $gc_probability = 1;
-
- /**
- * Garbage collection: delete all entries not use for n seconds.
- *
- * Default is one day, 60 * 60 * 24 = 86400 seconds.
- *
- * @var integer
- * @see $gc_probability, $gc_time
- */
- var $gc_maxlifetime = 86400;
-
- /**
- * Storage container object.
- *
- * @var object Cache_Container
- */
- var $container;
-
- //
- // public methods
- //
-
- /**
- *
- * @param string Name of container class
- * @param array Array with container class options
- */
- function Cache($container, $container_options = '')
- {
- $this->PEAR();
- $container = strtolower($container);
- $container_class = 'Cache_Container_' . $container;
- $container_classfile = 'Cache/Container/' . $container . '.php';
-
- include_once $container_classfile;
- $this->container = new $container_class($container_options);
- }
-
- //deconstructor
- function _Cache()
- {
- $this->garbageCollection();
- }
-
- /**
- * Returns the current caching state.
- *
- * @return boolean The current caching state.
- * @access public
- */
- function getCaching()
- {
- return ($this->caching);
- }
-
- /**
- * Enables or disables caching.
- *
- * @param boolean The new caching state.
- * @access public
- */
- function setCaching($state)
- {
- $this->caching = $state;
- }
-
- /**
- * Returns the requested dataset it if exists and is not expired
- *
- * @param string dataset ID
- * @param string cache group
- * @return mixed cached data or NULL on failure
- * @access public
- */
- function get($id, $group = 'default') {
- if (!$this->caching)
- return '';
-
- if ($this->isCached($id, $group) && !$this->isExpired($id, $group))
- return $this->load($id, $group);
-
- return NULL;
- } // end func get
-
- /**
- * Stores the given data in the cache.
- *
- * @param string dataset ID used as cache identifier
- * @param mixed data to cache
- * @param integer lifetime of the cached data in seconds - 0 for endless
- * @param string cache group
- * @return boolean
- * @access public
- */
- function save($id, $data, $expires = 0, $group = 'default') {
- if (!$this->caching)
- return true;
-
- return $this->extSave($id, $data, '',$expires, $group);
- } // end func save
-
- /**
- * Stores a dataset without additional userdefined data.
- *
- * @param string dataset ID
- * @param mixed data to store
- * @param string additional userdefined data
- * @param mixed userdefined expire date
- * @param string cache group
- * @return boolean
- * @throws Cache_Error
- * @access public
- * @see getUserdata()
- */
- function extSave($id, $cachedata, $userdata, $expires = 0, $group = 'default') {
- if (!$this->caching)
- return true;
-
- return $this->container->save($id, $cachedata, $expires, $group, $userdata);
- } // end func extSave
-
- /**
- * Loads the given ID from the cache.
- *
- * @param string dataset ID
- * @param string cache group
- * @return mixed cached data or NULL on failure
- * @access public
- */
- function load($id, $group = 'default') {
- if (!$this->caching)
- return '';
-
- return $this->container->load($id, $group);
- } // end func load
-
- /**
- * Returns the userdata field of a cached data set.
- *
- * @param string dataset ID
- * @param string cache group
- * @return string userdata
- * @access public
- * @see extSave()
- */
- function getUserdata($id, $group = 'default') {
- if (!$this->caching)
- return '';
-
- return $this->container->getUserdata($id, $group);
- } // end func getUserdata
-
- /**
- * Removes the specified dataset from the cache.
- *
- * @param string dataset ID
- * @param string cache group
- * @return boolean
- * @access public
- */
- function remove($id, $group = 'default') {
- if (!$this->caching)
- return true;
-
- return $this->container->remove($id, $group);
- } // end func remove
-
- /**
- * Flushes the cache - removes all data from it
- *
- * @param string cache group, if empty all groups will be flashed
- * @return integer number of removed datasets
- */
- function flush($group = 'default') {
- if (!$this->caching)
- return true;
-
- return $this->container->flush($group);
- } // end func flush
-
- /**
- * Checks if a dataset exists.
- *
- * Note: this does not say that the cached data is not expired!
- *
- * @param string dataset ID
- * @param string cache group
- * @return boolean
- * @access public
- */
- function isCached($id, $group = 'default') {
- if (!$this->caching)
- return false;
-
- return $this->container->isCached($id, $group);
- } // end func isCached
-
- /**
- * Checks if a dataset is expired
- *
- * @param string dataset ID
- * @param string cache group
- * @param integer maximum age for the cached data in seconds - 0 for endless
- * If the cached data is older but the given lifetime it will
- * be removed from the cache. You don't have to provide this
- * argument if you call isExpired(). Every dataset knows
- * it's expire date and will be removed automatically. Use
- * this only if you know what you're doing...
- * @return boolean
- * @access public
- */
- function isExpired($id, $group = 'default', $max_age = 0) {
- if (!$this->caching)
- return true;
-
- return $this->container->isExpired($id, $group, $max_age);
- } // end func isExpired
-
- /**
- * Generates a "unique" ID for the given value
- *
- * This is a quick but dirty hack to get a "unique" ID for a any kind of variable.
- * ID clashes might occur from time to time although they are extreme unlikely!
- *
- * @param mixed variable to generate a ID for
- * @return string "unique" ID
- * @access public
- */
- function generateID($variable) {
- // WARNING: ID clashes are possible although unlikely
- return md5(serialize($variable));
- }
-
- /**
- * Calls the garbage collector of the storage object with a certain probability
- *
- * @param boolean Force a garbage collection run?
- * @see $gc_probability, $gc_time
- */
- function garbageCollection($force = false) {
- static $last_run = 0;
-
- if (!$this->caching)
- return;
-
- srand((double) microtime() * 1000000);
-
- // time and probability based
- if (($force) || ($last_run && $last_run < time() + $this->gc_time) || (rand(1, 100) < $this->gc_probability)) {
- $this->container->garbageCollection($this->gc_maxlifetime);
- $last_run = time();
- }
- } // end func garbageCollection
-
-} // end class cache
-?>
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