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diff --git a/includes/CacheHelper.php b/includes/CacheHelper.php
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+<?php
+/**
+ * Cache of various elements in a single cache entry.
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @licence GNU GPL v2 or later
+ * @author Jeroen De Dauw < jeroendedauw@gmail.com >
+ */
+
+/**
+ * Interface for all classes implementing CacheHelper functionality.
+ *
+ * @since 1.20
+ */
+interface ICacheHelper {
+
+	/**
+	 * Sets if the cache should be enabled or not.
+	 *
+	 * @since 1.20
+	 * @param boolean $cacheEnabled
+	 */
+	function setCacheEnabled( $cacheEnabled );
+
+	/**
+	 * Initializes the caching.
+	 * Should be called before the first time anything is added via addCachedHTML.
+	 *
+	 * @since 1.20
+	 *
+	 * @param integer|null $cacheExpiry Sets the cache expiry, either ttl in seconds or unix timestamp.
+	 * @param boolean|null $cacheEnabled Sets if the cache should be enabled or not.
+	 */
+	function startCache( $cacheExpiry = null, $cacheEnabled = null );
+
+	/**
+	 * Get a cached value if available or compute it if not and then cache it if possible.
+	 * The provided $computeFunction is only called when the computation needs to happen
+	 * and should return a result value. $args are arguments that will be passed to the
+	 * compute function when called.
+	 *
+	 * @since 1.20
+	 *
+	 * @param {function} $computeFunction
+	 * @param array|mixed $args
+	 * @param string|null $key
+	 *
+	 * @return mixed
+	 */
+	function getCachedValue( $computeFunction, $args = array(), $key = null );
+
+	/**
+	 * Saves the HTML to the cache in case it got recomputed.
+	 * Should be called after the last time anything is added via addCachedHTML.
+	 *
+	 * @since 1.20
+	 */
+	function saveCache();
+
+	/**
+	 * Sets the time to live for the cache, in seconds or a unix timestamp
+	 * indicating the point of expiry...
+	 *
+	 * @since 1.20
+	 *
+	 * @param integer $cacheExpiry
+	 */
+	function setExpiry( $cacheExpiry );
+
+}
+
+/**
+ * Helper class for caching various elements in a single cache entry.
+ *
+ * To get a cached value or compute it, use getCachedValue like this:
+ * $this->getCachedValue( $callback );
+ *
+ * To add HTML that should be cached, use addCachedHTML like this:
+ * $this->addCachedHTML( $callback );
+ *
+ * The callback function is only called when needed, so do all your expensive
+ * computations here. This function should returns the HTML to be cached.
+ * It should not add anything to the PageOutput object!
+ *
+ * Before the first addCachedHTML call, you should call $this->startCache();
+ * After adding the last HTML that should be cached, call $this->saveCache();
+ *
+ * @since 1.20
+ */
+class CacheHelper implements ICacheHelper {
+
+	/**
+	 * The time to live for the cache, in seconds or a unix timestamp indicating the point of expiry.
+	 *
+	 * @since 1.20
+	 * @var integer
+	 */
+	protected $cacheExpiry = 3600;
+
+	/**
+	 * List of HTML chunks to be cached (if !hasCached) or that where cached (of hasCached).
+	 * If not cached already, then the newly computed chunks are added here,
+	 * if it as cached already, chunks are removed from this list as they are needed.
+	 *
+	 * @since 1.20
+	 * @var array
+	 */
+	protected $cachedChunks;
+
+	/**
+	 * Indicates if the to be cached content was already cached.
+	 * Null if this information is not available yet.
+	 *
+	 * @since 1.20
+	 * @var boolean|null
+	 */
+	protected $hasCached = null;
+
+	/**
+	 * If the cache is enabled or not.
+	 *
+	 * @since 1.20
+	 * @var boolean
+	 */
+	protected $cacheEnabled = true;
+
+	/**
+	 * Function that gets called when initialization is done.
+	 *
+	 * @since 1.20
+	 * @var callable
+	 */
+	protected $onInitHandler = false;
+
+	/**
+	 * Elements to build a cache key with.
+	 *
+	 * @since 1.20
+	 * @var array
+	 */
+	protected $cacheKey = array();
+
+	/**
+	 * Sets if the cache should be enabled or not.
+	 *
+	 * @since 1.20
+	 * @param boolean $cacheEnabled
+	 */
+	public function setCacheEnabled( $cacheEnabled ) {
+		$this->cacheEnabled = $cacheEnabled;
+	}
+
+	/**
+	 * Initializes the caching.
+	 * Should be called before the first time anything is added via addCachedHTML.
+	 *
+	 * @since 1.20
+	 *
+	 * @param integer|null $cacheExpiry Sets the cache expiry, either ttl in seconds or unix timestamp.
+	 * @param boolean|null $cacheEnabled Sets if the cache should be enabled or not.
+	 */
+	public function startCache( $cacheExpiry = null, $cacheEnabled = null ) {
+		if ( is_null( $this->hasCached ) ) {
+			if ( !is_null( $cacheExpiry ) ) {
+				$this->cacheExpiry = $cacheExpiry;
+			}
+
+			if ( !is_null( $cacheEnabled ) ) {
+				$this->setCacheEnabled( $cacheEnabled );
+			}
+
+			$this->initCaching();
+		}
+	}
+
+	/**
+	 * Returns a message that notifies the user he/she is looking at
+	 * a cached version of the page, including a refresh link.
+	 *
+	 * @since 1.20
+	 *
+	 * @param IContextSource $context
+	 * @param boolean $includePurgeLink
+	 *
+	 * @return string
+	 */
+	public function getCachedNotice( IContextSource $context, $includePurgeLink = true ) {
+		if ( $this->cacheExpiry < 86400 * 3650 ) {
+			$message = $context->msg(
+				'cachedspecial-viewing-cached-ttl',
+				$context->getLanguage()->formatDuration( $this->cacheExpiry )
+			)->escaped();
+		}
+		else {
+			$message = $context->msg(
+				'cachedspecial-viewing-cached-ts'
+			)->escaped();
+		}
+
+		if ( $includePurgeLink ) {
+			$refreshArgs = $context->getRequest()->getQueryValues();
+			unset( $refreshArgs['title'] );
+			$refreshArgs['action'] = 'purge';
+
+			$subPage = $context->getTitle()->getFullText();
+			$subPage = explode( '/', $subPage, 2 );
+			$subPage = count( $subPage ) > 1 ? $subPage[1] : false;
+
+			$message .= ' ' . Linker::link(
+				$context->getTitle( $subPage ),
+				$context->msg( 'cachedspecial-refresh-now' )->escaped(),
+				array(),
+				$refreshArgs
+			);
+		}
+
+		return $message;
+	}
+
+	/**
+	 * Initializes the caching if not already done so.
+	 * Should be called before any of the caching functionality is used.
+	 *
+	 * @since 1.20
+	 */
+	protected function initCaching() {
+		if ( $this->cacheEnabled && is_null( $this->hasCached ) ) {
+			$cachedChunks = wfGetCache( CACHE_ANYTHING )->get( $this->getCacheKeyString() );
+
+			$this->hasCached = is_array( $cachedChunks );
+			$this->cachedChunks = $this->hasCached ? $cachedChunks : array();
+
+			if ( $this->onInitHandler !== false ) {
+				call_user_func( $this->onInitHandler, $this->hasCached );
+			}
+		}
+	}
+
+	/**
+	 * Get a cached value if available or compute it if not and then cache it if possible.
+	 * The provided $computeFunction is only called when the computation needs to happen
+	 * and should return a result value. $args are arguments that will be passed to the
+	 * compute function when called.
+	 *
+	 * @since 1.20
+	 *
+	 * @param {function} $computeFunction
+	 * @param array|mixed $args
+	 * @param string|null $key
+	 *
+	 * @return mixed
+	 */
+	public function getCachedValue( $computeFunction, $args = array(), $key = null ) {
+		$this->initCaching();
+
+		if ( $this->cacheEnabled && $this->hasCached ) {
+			$value = null;
+
+			if ( is_null( $key ) ) {
+				$itemKey = array_keys( array_slice( $this->cachedChunks, 0, 1 ) );
+				$itemKey = array_shift( $itemKey );
+
+				if ( !is_integer( $itemKey ) ) {
+					wfWarn( "Attempted to get item with non-numeric key while the next item in the queue has a key ($itemKey) in " . __METHOD__ );
+				}
+				elseif ( is_null( $itemKey ) ) {
+					wfWarn( "Attempted to get an item while the queue is empty in " . __METHOD__ );
+				}
+				else {
+					$value = array_shift( $this->cachedChunks );
+				}
+			}
+			else {
+				if ( array_key_exists( $key, $this->cachedChunks ) ) {
+					$value = $this->cachedChunks[$key];
+					unset( $this->cachedChunks[$key] );
+				}
+				else {
+					wfWarn( "There is no item with key '$key' in this->cachedChunks in " . __METHOD__ );
+				}
+			}
+		}
+		else {
+			if ( !is_array( $args ) ) {
+				$args = array( $args );
+			}
+
+			$value = call_user_func_array( $computeFunction, $args );
+
+			if ( $this->cacheEnabled ) {
+				if ( is_null( $key ) ) {
+					$this->cachedChunks[] = $value;
+				}
+				else {
+					$this->cachedChunks[$key] = $value;
+				}
+			}
+		}
+
+		return $value;
+	}
+
+	/**
+	 * Saves the HTML to the cache in case it got recomputed.
+	 * Should be called after the last time anything is added via addCachedHTML.
+	 *
+	 * @since 1.20
+	 */
+	public function saveCache() {
+		if ( $this->cacheEnabled && $this->hasCached === false && !empty( $this->cachedChunks ) ) {
+			wfGetCache( CACHE_ANYTHING )->set( $this->getCacheKeyString(), $this->cachedChunks, $this->cacheExpiry );
+		}
+	}
+
+	/**
+	 * Sets the time to live for the cache, in seconds or a unix timestamp
+	 * indicating the point of expiry...
+	 *
+	 * @since 1.20
+	 *
+	 * @param integer $cacheExpiry
+	 */
+	public function setExpiry( $cacheExpiry ) {
+		$this->cacheExpiry = $cacheExpiry;
+	}
+
+	/**
+	 * Returns the cache key to use to cache this page's HTML output.
+	 * Is constructed from the special page name and language code.
+	 *
+	 * @since 1.20
+	 *
+	 * @return string
+	 * @throws MWException
+	 */
+	protected function getCacheKeyString() {
+		if ( $this->cacheKey === array() ) {
+			throw new MWException( 'No cache key set, so cannot obtain or save the CacheHelper values.' );
+		}
+
+		return call_user_func_array( 'wfMemcKey', $this->cacheKey );
+	}
+
+	/**
+	 * Sets the cache key that should be used.
+	 *
+	 * @since 1.20
+	 *
+	 * @param array $cacheKey
+	 */
+	public function setCacheKey( array $cacheKey ) {
+		$this->cacheKey = $cacheKey;
+	}
+
+	/**
+	 * Rebuild the content, even if it's already cached.
+	 * This effectively has the same effect as purging the cache,
+	 * since it will be overridden with the new value on the next request.
+	 *
+	 * @since 1.20
+	 */
+	public function rebuildOnDemand() {
+		$this->hasCached = false;
+	}
+
+	/**
+	 * Sets a function that gets called when initialization of the cache is done.
+	 *
+	 * @since 1.20
+	 *
+	 * @param $handlerFunction
+	 */
+	public function setOnInitializedHandler( $handlerFunction ) {
+		$this->onInitHandler = $handlerFunction;
+	}
+
+}