/libraries/joomla/cache/controller/page.php

  1<?php
  2/**
  3 * @package     Joomla.Platform
  4 * @subpackage  Cache
  5 *
  6 * @copyright   Copyright (C) 2005 - 2012 Open Source Matters, Inc. All rights reserved.
  7 * @license     GNU General Public License version 2 or later; see LICENSE
  8 */
  9
 10defined('JPATH_PLATFORM') or die;
 11
 12/**
 13 * Joomla! Cache page type object
 14 *
 15 * @package     Joomla.Platform
 16 * @subpackage  Cache
 17 * @since       11.1
 18 */
 19class JCacheControllerPage extends JCacheController
 20{
 21	/**
 22	 * @var    integer  ID property for the cache page object.
 23	 * @since  11.1
 24	 */
 25	protected $_id;
 26
 27	/**
 28	 * @var    string  Cache group
 29	 * @since  11.1
 30	 */
 31	protected $_group;
 32
 33	/**
 34	 * @var    object  Cache lock test
 35	 * @since  11.1
 36	 */
 37	protected $_locktest = null;
 38
 39	/**
 40	 * Get the cached page data
 41	 *
 42	 * @param   string   $id          The cache data id
 43	 * @param   string   $group       The cache data group
 44	 * @param   boolean  $wrkarounds  True to use wrkarounds
 45	 *
 46	 * @return  boolean  True if the cache is hit (false else)
 47	 *
 48	 * @since   11.1
 49	 */
 50	public function get($id = false, $group = 'page', $wrkarounds = true)
 51	{
 52		// If an id is not given, generate it from the request
 53		if ($id == false)
 54		{
 55			$id = $this->_makeId();
 56		}
 57
 58		// If the etag matches the page id ... set a no change header and exit : utilize browser cache
 59		if (!headers_sent() && isset($_SERVER['HTTP_IF_NONE_MATCH']))
 60		{
 61			$etag = stripslashes($_SERVER['HTTP_IF_NONE_MATCH']);
 62			if ($etag == $id)
 63			{
 64				$browserCache = isset($this->options['browsercache']) ? $this->options['browsercache'] : false;
 65				if ($browserCache)
 66				{
 67					$this->_noChange();
 68				}
 69			}
 70		}
 71
 72		// We got a cache hit... set the etag header and echo the page data
 73		$data = $this->cache->get($id, $group);
 74
 75		$this->_locktest = new stdClass;
 76		$this->_locktest->locked = null;
 77		$this->_locktest->locklooped = null;
 78
 79		if ($data === false)
 80		{
 81			$this->_locktest = $this->cache->lock($id, $group);
 82			if ($this->_locktest->locked == true && $this->_locktest->locklooped == true)
 83			{
 84				$data = $this->cache->get($id, $group);
 85			}
 86		}
 87
 88		if ($data !== false)
 89		{
 90			$data = unserialize(trim($data));
 91			if ($wrkarounds === true)
 92			{
 93				$data = JCache::getWorkarounds($data);
 94			}
 95
 96			$this->_setEtag($id);
 97			if ($this->_locktest->locked == true)
 98			{
 99				$this->cache->unlock($id, $group);
100			}
101			return $data;
102		}
103
104		// Set id and group placeholders
105		$this->_id = $id;
106		$this->_group = $group;
107		return false;
108	}
109
110	/**
111	 * Stop the cache buffer and store the cached data
112	 *
113	 * @param   boolean  $wrkarounds  True to use wrkarounds
114	 *
115	 * @return  boolean  True if cache stored
116	 *
117	 * @since   11.1
118	 */
119	public function store($wrkarounds = true)
120	{
121		// Get page data from JResponse body
122		$data = JResponse::getBody();
123
124		// Get id and group and reset the placeholders
125		$id = $this->_id;
126		$group = $this->_group;
127		$this->_id = null;
128		$this->_group = null;
129
130		// Only attempt to store if page data exists
131		if ($data)
132		{
133			$data = $wrkarounds == false ? $data : JCache::setWorkarounds($data);
134
135			if ($this->_locktest->locked == false)
136			{
137				$this->_locktest = $this->cache->lock($id, $group);
138			}
139
140			$sucess = $this->cache->store(serialize($data), $id, $group);
141
142			if ($this->_locktest->locked == true)
143			{
144				$this->cache->unlock($id, $group);
145			}
146
147			return $sucess;
148		}
149		return false;
150	}
151
152	/**
153	 * Generate a page cache id
154	 *
155	 * @return  string  MD5 Hash : page cache id
156	 *
157	 * @since   11.1
158	 * @todo    Discuss whether this should be coupled to a data hash or a request
159	 * hash ... perhaps hashed with a serialized request
160	 */
161	protected function _makeId()
162	{
163		return JCache::makeId();
164	}
165
166	/**
167	 * There is no change in page data so send an
168	 * unmodified header and die gracefully
169	 *
170	 * @return  void
171	 *
172	 * @since   11.1
173	 */
174	protected function _noChange()
175	{
176		$app = JFactory::getApplication();
177
178		// Send not modified header and exit gracefully
179		header('HTTP/1.x 304 Not Modified', true);
180		$app->close();
181	}
182
183	/**
184	 * Set the ETag header in the response
185	 *
186	 * @param   string  $etag  The entity tag (etag) to set
187	 *
188	 * @return  void
189	 *
190	 * @since   11.1
191	 */
192	protected function _setEtag($etag)
193	{
194		JResponse::setHeader('ETag', $etag, true);
195	}
196}