Drop hard-deprecated CacheHelper classes

Bug: T249230
Change-Id: I8fb43e862a19031520dda5a147e533becd7eb89e

6 files changed, 2 insertions, 822 deletions

diff --git a/RELEASE-NOTES-1.37 b/RELEASE-NOTES-1.37
index 26acc4dd2414..a75e5ab24d3b 100644
--- a/RELEASE-NOTES-1.37
+++ b/RELEASE-NOTES-1.37
@@ -89,6 +89,8 @@ because of Phabricator reports.
   Use WatchlistManager::clearTitleUserNotification() instead.
 * Autopromote class, deprecated since 1.35, was removed. Use
   UserGroupManager instead.
+* The following classes, hard-deprecated since 1.36, have been removed:
+  CachedAction, SpecialCachedPage, CacheHelper, ICacheHelper.
 
 === Deprecations in 1.37 ===
 * JobQueue::getWiki, deprecated in 1.33, now emits deprecation warnings.
diff --git a/autoload.php b/autoload.php
index ece09e5b32e3..487b74880657 100644
--- a/autoload.php
+++ b/autoload.php
@@ -215,9 +215,7 @@ $wgAutoloadLocalClasses = [
 	'BufferingStatsdDataFactory' => __DIR__ . '/includes/libs/stats/BufferingStatsdDataFactory.php',
 	'CLIParser' => __DIR__ . '/maintenance/parse.php',
 	'CacheDependency' => __DIR__ . '/includes/cache/dependency/CacheDependency.php',
-	'CacheHelper' => __DIR__ . '/includes/cache/CacheHelper.php',
 	'CacheTime' => __DIR__ . '/includes/parser/CacheTime.php',
-	'CachedAction' => __DIR__ . '/includes/actions/CachedAction.php',
 	'CachedBagOStuff' => __DIR__ . '/includes/libs/objectcache/CachedBagOStuff.php',
 	'CachingSiteStore' => __DIR__ . '/includes/site/CachingSiteStore.php',
 	'CannotCreateActorException' => __DIR__ . '/includes/exception/CannotCreateActorException.php',
@@ -637,7 +635,6 @@ $wgAutoloadLocalClasses = [
 	'HttpStatus' => __DIR__ . '/includes/libs/HttpStatus.php',
 	'IApiMessage' => __DIR__ . '/includes/api/IApiMessage.php',
 	'IBufferingStatsdDataFactory' => __DIR__ . '/includes/libs/stats/IBufferingStatsdDataFactory.php',
-	'ICacheHelper' => __DIR__ . '/includes/cache/ICacheHelper.php',
 	'IContextSource' => __DIR__ . '/includes/context/IContextSource.php',
 	'IDBAccessObject' => __DIR__ . '/includes/dao/IDBAccessObject.php',
 	'IDatabase' => __DIR__ . '/includes/libs/rdbms/database/IDatabase.php',
@@ -1493,7 +1490,6 @@ $wgAutoloadLocalClasses = [
 	'SpecialBookSources' => __DIR__ . '/includes/specials/SpecialBookSources.php',
 	'SpecialBotPasswords' => __DIR__ . '/includes/specials/SpecialBotPasswords.php',
 	'SpecialBrokenRedirects' => __DIR__ . '/includes/specials/SpecialBrokenRedirects.php',
-	'SpecialCachedPage' => __DIR__ . '/includes/specials/SpecialCachedPage.php',
 	'SpecialCategories' => __DIR__ . '/includes/specials/SpecialCategories.php',
 	'SpecialChangeContentModel' => __DIR__ . '/includes/specials/SpecialChangeContentModel.php',
 	'SpecialChangeCredentials' => __DIR__ . '/includes/specials/SpecialChangeCredentials.php',
diff --git a/includes/actions/CachedAction.php b/includes/actions/CachedAction.php
deleted file mode 100644
index 5345d60806e9..000000000000
--- a/includes/actions/CachedAction.php
+++ /dev/null
@@ -1,197 +0,0 @@
-<?php
-/**
- * Abstract action class with scaffolding for caching HTML and other values
- * in a single blob.
- *
- * 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
- * @ingroup Actions
- * @author Jeroen De Dauw < jeroendedauw@gmail.com >
- * @since 1.20
- */
-
-/**
- * Abstract action class with scaffolding for caching HTML and other values
- * in a single blob.
- *
- * Before using any of the caching functionality, call startCache.
- * After the last call to either getCachedValue or addCachedHTML, call saveCache.
- *
- * 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!
- *
- * @ingroup Actions
- */
-abstract class CachedAction extends FormlessAction implements ICacheHelper {
-
-	/**
-	 * CacheHelper object to which we forward the non-SpecialPage specific caching work.
-	 * Initialized in startCache.
-	 *
-	 * @since 1.20
-	 * @var CacheHelper
-	 */
-	protected $cacheHelper;
-
-	/**
-	 * If the cache is enabled or not.
-	 *
-	 * @since 1.20
-	 * @var bool
-	 */
-	protected $cacheEnabled = true;
-
-	public function __construct(
-		Page $page,
-		IContextSource $context = null
-	) {
-		parent::__construct( $page, $context );
-		wfDeprecated( __CLASS__, '1.36' );
-	}
-
-	/**
-	 * Sets if the cache should be enabled or not.
-	 *
-	 * @since 1.20
-	 * @param bool $cacheEnabled
-	 */
-	public function setCacheEnabled( $cacheEnabled ) {
-		$this->cacheHelper->setCacheEnabled( $cacheEnabled );
-	}
-
-	/**
-	 * Initializes the caching.
-	 * Should be called before the first time anything is added via addCachedHTML.
-	 *
-	 * @since 1.20
-	 *
-	 * @param int|null $cacheExpiry Sets the cache expiry, either ttl in seconds or unix timestamp.
-	 * @param bool|null $cacheEnabled Sets if the cache should be enabled or not.
-	 */
-	public function startCache( $cacheExpiry = null, $cacheEnabled = null ) {
-		$this->cacheHelper = new CacheHelper();
-
-		$this->cacheHelper->setCacheEnabled( $this->cacheEnabled );
-		$this->cacheHelper->setOnInitializedHandler( [ $this, 'onCacheInitialized' ] );
-
-		$keyArgs = $this->getCacheKey();
-
-		if ( array_key_exists( 'action', $keyArgs ) && $keyArgs['action'] === 'purge' ) {
-			unset( $keyArgs['action'] );
-		}
-
-		$this->cacheHelper->setCacheKey( $keyArgs );
-
-		if ( $this->getRequest()->getText( 'action' ) === 'purge' ) {
-			$this->cacheHelper->rebuildOnDemand();
-		}
-
-		$this->cacheHelper->startCache( $cacheExpiry, $cacheEnabled );
-	}
-
-	/**
-	 * 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 callable $computeFunction
-	 * @param array|mixed $args
-	 * @param string|null $key
-	 *
-	 * @return mixed
-	 */
-	public function getCachedValue( $computeFunction, $args = [], $key = null ) {
-		return $this->cacheHelper->getCachedValue( $computeFunction, $args, $key );
-	}
-
-	/**
-	 * Add some HTML to be cached.
-	 * This is done by providing a callback function that should
-	 * return the HTML to be added. It will only be called if the
-	 * item is not in the cache yet or when the cache has been invalidated.
-	 *
-	 * @since 1.20
-	 *
-	 * @param callable $computeFunction
-	 * @param array $args
-	 * @param string|null $key
-	 */
-	public function addCachedHTML( $computeFunction, $args = [], $key = null ) {
-		$html = $this->cacheHelper->getCachedValue( $computeFunction, $args, $key );
-		$this->getOutput()->addHTML( $html );
-	}
-
-	/**
-	 * 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() {
-		$this->cacheHelper->saveCache();
-	}
-
-	/**
-	 * Sets the time to live for the cache, in seconds or a unix timestamp
-	 * indicating the point of expiry.
-	 *
-	 * @since 1.20
-	 *
-	 * @param int $cacheExpiry
-	 */
-	public function setExpiry( $cacheExpiry ) {
-		$this->cacheHelper->setExpiry( $cacheExpiry );
-	}
-
-	/**
-	 * Returns the variables used to constructed the cache key in an array.
-	 *
-	 * @since 1.20
-	 *
-	 * @return array
-	 */
-	protected function getCacheKey() {
-		return [
-			get_class( $this->getArticle() ),
-			$this->getName(),
-			$this->getLanguage()->getCode()
-		];
-	}
-
-	/**
-	 * Gets called after the cache got initialized.
-	 *
-	 * @since 1.20
-	 *
-	 * @param bool $hasCached
-	 */
-	public function onCacheInitialized( $hasCached ) {
-		if ( $hasCached ) {
-			$this->getOutput()->setSubtitle( $this->cacheHelper->getCachedNotice( $this->getContext() ) );
-		}
-	}
-}
diff --git a/includes/cache/CacheHelper.php b/includes/cache/CacheHelper.php
deleted file mode 100644
index ada950eb256d..000000000000
--- a/includes/cache/CacheHelper.php
+++ /dev/null
@@ -1,328 +0,0 @@
-<?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
- * @license GPL-2.0-or-later
- * @author Jeroen De Dauw < jeroendedauw@gmail.com >
- */
-
-use MediaWiki\MediaWikiServices;
-
-/**
- * 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 int
-	 */
-	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 bool|null
-	 */
-	protected $hasCached = null;
-
-	/**
-	 * If the cache is enabled or not.
-	 *
-	 * @since 1.20
-	 * @var bool
-	 */
-	protected $cacheEnabled = true;
-
-	/**
-	 * Function that gets called when initialization is done.
-	 *
-	 * @since 1.20
-	 * @var callable|null
-	 */
-	protected $onInitHandler;
-
-	/**
-	 * Elements to build a cache key with.
-	 *
-	 * @since 1.20
-	 * @var array
-	 */
-	protected $cacheKey = [];
-
-	public function __construct() {
-		wfDeprecated( __CLASS__, '1.36' );
-	}
-
-	/**
-	 * Sets if the cache should be enabled or not.
-	 *
-	 * @since 1.20
-	 * @param bool $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 int|null $cacheExpiry Sets the cache expiry, either ttl in seconds or unix timestamp.
-	 * @param bool|null $cacheEnabled Sets if the cache should be enabled or not.
-	 */
-	public function startCache( $cacheExpiry = null, $cacheEnabled = null ) {
-		if ( $this->hasCached === null ) {
-			if ( $cacheExpiry !== null ) {
-				$this->cacheExpiry = $cacheExpiry;
-			}
-
-			if ( $cacheEnabled !== null ) {
-				$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 bool $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';
-
-			$message .= ' ' . MediaWikiServices::getInstance()->getLinkRenderer()->makeLink(
-				$context->getTitle(),
-				$context->msg( 'cachedspecial-refresh-now' )->text(),
-				[],
-				$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 && $this->hasCached === null ) {
-			$cachedChunks = ObjectCache::getInstance( CACHE_ANYTHING )->get( $this->getCacheKeyString() );
-
-			$this->hasCached = is_array( $cachedChunks );
-			$this->cachedChunks = $this->hasCached ? $cachedChunks : [];
-
-			if ( $this->onInitHandler !== null ) {
-				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 callable $computeFunction
-	 * @param array|mixed $args
-	 * @param string|null $key
-	 *
-	 * @return mixed
-	 */
-	public function getCachedValue( $computeFunction, $args = [], $key = null ) {
-		$this->initCaching();
-
-		if ( $this->cacheEnabled && $this->hasCached ) {
-			$value = null;
-
-			if ( $key === null ) {
-				reset( $this->cachedChunks );
-				$itemKey = key( $this->cachedChunks );
-
-				if ( $itemKey === null ) {
-					wfWarn( "Attempted to get an item while the queue is empty in " . __METHOD__ );
-				} elseif ( !is_int( $itemKey ) ) {
-					wfWarn( "Attempted to get item with non-numeric key while " .
-						"the next item in the queue has a key ($itemKey) in " . __METHOD__ );
-				} else {
-					$value = array_shift( $this->cachedChunks );
-				}
-			} elseif ( 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 = [ $args ];
-			}
-
-			$value = $computeFunction( ...$args );
-
-			if ( $this->cacheEnabled ) {
-				if ( $key === null ) {
-					$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 ) ) {
-			ObjectCache::getInstance( 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 int $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 === [] ) {
-			throw new MWException( 'No cache key set, so cannot obtain or save the CacheHelper values.' );
-		}
-
-		return ObjectCache::getLocalClusterInstance()->makeKey(
-			...array_values( $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 callable $handlerFunction
-	 */
-	public function setOnInitializedHandler( $handlerFunction ) {
-		$this->onInitHandler = $handlerFunction;
-	}
-}
diff --git a/includes/cache/ICacheHelper.php b/includes/cache/ICacheHelper.php
deleted file mode 100644
index bdac12c6443c..000000000000
--- a/includes/cache/ICacheHelper.php
+++ /dev/null
@@ -1,84 +0,0 @@
-<?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
- * @license GPL-2.0-or-later
- * @author Jeroen De Dauw < jeroendedauw@gmail.com >
- */
-
-/**
- * Interface for all classes implementing CacheHelper functionality.
- *
- * @deprecated since 1.36
- * @since 1.20
- */
-interface ICacheHelper {
-	/**
-	 * Sets if the cache should be enabled or not.
-	 *
-	 * @since 1.20
-	 * @param bool $cacheEnabled
-	 */
-	public function setCacheEnabled( $cacheEnabled );
-
-	/**
-	 * Initializes the caching.
-	 * Should be called before the first time anything is added via addCachedHTML.
-	 *
-	 * @since 1.20
-	 *
-	 * @param int|null $cacheExpiry Sets the cache expiry, either ttl in seconds or unix timestamp.
-	 * @param bool|null $cacheEnabled Sets if the cache should be enabled or not.
-	 */
-	public 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 callable $computeFunction
-	 * @param array|mixed $args
-	 * @param string|null $key
-	 *
-	 * @return mixed
-	 */
-	public function getCachedValue( $computeFunction, $args = [], $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
-	 */
-	public 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 int $cacheExpiry
-	 */
-	public function setExpiry( $cacheExpiry );
-}
diff --git a/includes/specials/SpecialCachedPage.php b/includes/specials/SpecialCachedPage.php
deleted file mode 100644
index 8be22b9c6b73..000000000000
--- a/includes/specials/SpecialCachedPage.php
+++ /dev/null
@@ -1,209 +0,0 @@
-<?php
-
-/**
- * Abstract special page class with scaffolding for caching HTML and other values
- * in a single blob.
- *
- * Before using any of the caching functionality, call startCache.
- * After the last call to either getCachedValue or addCachedHTML, call saveCache.
- *
- * 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!
- *
- * 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
- * @ingroup SpecialPage
- * @author Jeroen De Dauw < jeroendedauw@gmail.com >
- * @since 1.20
- */
-abstract class SpecialCachedPage extends SpecialPage implements ICacheHelper {
-	/**
-	 * CacheHelper object to which we forward the non-SpecialPage specific caching work.
-	 * Initialized in startCache.
-	 *
-	 * @since 1.20
-	 * @var CacheHelper
-	 */
-	protected $cacheHelper;
-
-	/**
-	 * If the cache is enabled or not.
-	 *
-	 * @since 1.20
-	 * @var bool
-	 */
-	protected $cacheEnabled = true;
-
-	public function __construct(
-		$name = '', $restriction = '', $listed = true,
-		$function = false, $file = '', $includable = false
-	) {
-		parent::__construct( $name, $restriction, $listed, $function, $file, $includable );
-		wfDeprecated( __CLASS__, '1.36' );
-	}
-
-	/**
-	 * Gets called after @see SpecialPage::execute.
-	 *
-	 * @since 1.20
-	 *
-	 * @param string|null $subPage
-	 */
-	protected function afterExecute( $subPage ) {
-		$this->saveCache();
-
-		parent::afterExecute( $subPage );
-	}
-
-	/**
-	 * Sets if the cache should be enabled or not.
-	 *
-	 * @since 1.20
-	 * @param bool $cacheEnabled
-	 */
-	public function setCacheEnabled( $cacheEnabled ) {
-		$this->cacheHelper->setCacheEnabled( $cacheEnabled );
-	}
-
-	/**
-	 * Initializes the caching.
-	 * Should be called before the first time anything is added via addCachedHTML.
-	 *
-	 * @since 1.20
-	 *
-	 * @param int|null $cacheExpiry Sets the cache expiry, either ttl in seconds or unix timestamp.
-	 * @param bool|null $cacheEnabled Sets if the cache should be enabled or not.
-	 */
-	public function startCache( $cacheExpiry = null, $cacheEnabled = null ) {
-		if ( !isset( $this->cacheHelper ) ) {
-			$this->cacheHelper = new CacheHelper();
-
-			$this->cacheHelper->setCacheEnabled( $this->cacheEnabled );
-			$this->cacheHelper->setOnInitializedHandler( [ $this, 'onCacheInitialized' ] );
-
-			$keyArgs = $this->getCacheKey();
-
-			if ( array_key_exists( 'action', $keyArgs ) && $keyArgs['action'] === 'purge' ) {
-				unset( $keyArgs['action'] );
-			}
-
-			$this->cacheHelper->setCacheKey( $keyArgs );
-
-			if ( $this->getRequest()->getText( 'action' ) === 'purge' ) {
-				$this->cacheHelper->rebuildOnDemand();
-			}
-		}
-
-		$this->cacheHelper->startCache( $cacheExpiry, $cacheEnabled );
-	}
-
-	/**
-	 * 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 callable $computeFunction
-	 * @param array|mixed $args
-	 * @param string|null $key
-	 *
-	 * @return mixed
-	 */
-	public function getCachedValue( $computeFunction, $args = [], $key = null ) {
-		return $this->cacheHelper->getCachedValue( $computeFunction, $args, $key );
-	}
-
-	/**
-	 * Add some HTML to be cached.
-	 * This is done by providing a callback function that should
-	 * return the HTML to be added. It will only be called if the
-	 * item is not in the cache yet or when the cache has been invalidated.
-	 *
-	 * @since 1.20
-	 *
-	 * @param callable $computeFunction
-	 * @param array $args
-	 * @param string|null $key
-	 */
-	public function addCachedHTML( $computeFunction, $args = [], $key = null ) {
-		$this->getOutput()->addHTML( $this->cacheHelper->getCachedValue(
-			$computeFunction,
-			$args,
-			$key
-		) );
-	}
-
-	/**
-	 * 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 ( isset( $this->cacheHelper ) ) {
-			$this->cacheHelper->saveCache();
-		}
-	}
-
-	/**
-	 * Sets the time to live for the cache, in seconds or a unix timestamp
-	 * indicating the point of expiry.
-	 *
-	 * @since 1.20
-	 *
-	 * @param int $cacheExpiry
-	 */
-	public function setExpiry( $cacheExpiry ) {
-		$this->cacheHelper->setExpiry( $cacheExpiry );
-	}
-
-	/**
-	 * Returns the variables used to constructed the cache key in an array.
-	 *
-	 * @since 1.20
-	 *
-	 * @return array
-	 */
-	protected function getCacheKey() {
-		return [
-			$this->mName,
-			$this->getLanguage()->getCode()
-		];
-	}
-
-	/**
-	 * Gets called after the cache got initialized.
-	 *
-	 * @since 1.20
-	 *
-	 * @param bool $hasCached
-	 */
-	public function onCacheInitialized( $hasCached ) {
-		if ( $hasCached ) {
-			$this->getOutput()->setSubtitle( $this->cacheHelper->getCachedNotice( $this->getContext() ) );
-		}
-	}
-}