--- /dev/null
+<?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;
+
+ /**
+ * 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() ) );
+ }
+ }
+}
scripts.mit.edu / autoinstallsdev / mediawiki.git / blobdiff