--- /dev/null
+<?php
+/**
+ * Page existence cache.
+ *
+ * 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 Cache
+ */
+
+use Wikimedia\Rdbms\Database;
+use Wikimedia\Rdbms\IDatabase;
+use MediaWiki\Linker\LinkTarget;
+use MediaWiki\MediaWikiServices;
+
+/**
+ * Cache for article titles (prefixed DB keys) and ids linked from one source
+ *
+ * @ingroup Cache
+ */
+class LinkCache {
+ /** @var HashBagOStuff */
+ private $mGoodLinks;
+ /** @var HashBagOStuff */
+ private $mBadLinks;
+ /** @var WANObjectCache */
+ private $wanCache;
+
+ /** @var bool */
+ private $mForUpdate = false;
+
+ /** @var TitleFormatter */
+ private $titleFormatter;
+
+ /**
+ * How many Titles to store. There are two caches, so the amount actually
+ * stored in memory can be up to twice this.
+ */
+ const MAX_SIZE = 10000;
+
+ public function __construct( TitleFormatter $titleFormatter, WANObjectCache $cache ) {
+ $this->mGoodLinks = new HashBagOStuff( [ 'maxKeys' => self::MAX_SIZE ] );
+ $this->mBadLinks = new HashBagOStuff( [ 'maxKeys' => self::MAX_SIZE ] );
+ $this->wanCache = $cache;
+ $this->titleFormatter = $titleFormatter;
+ }
+
+ /**
+ * Get an instance of this class.
+ *
+ * @return LinkCache
+ * @deprecated since 1.28, use MediaWikiServices instead
+ */
+ public static function singleton() {
+ return MediaWikiServices::getInstance()->getLinkCache();
+ }
+
+ /**
+ * General accessor to get/set whether the master DB should be used
+ *
+ * This used to also set the FOR UPDATE option (locking the rows read
+ * in order to avoid link table inconsistency), which was later removed
+ * for performance on wikis with a high edit rate.
+ *
+ * @param bool $update
+ * @return bool
+ */
+ public function forUpdate( $update = null ) {
+ return wfSetVar( $this->mForUpdate, $update );
+ }
+
+ /**
+ * @param string $title Prefixed DB key
+ * @return int Page ID or zero
+ */
+ public function getGoodLinkID( $title ) {
+ $info = $this->mGoodLinks->get( $title );
+ if ( !$info ) {
+ return 0;
+ }
+ return $info['id'];
+ }
+
+ /**
+ * Get a field of a title object from cache.
+ * If this link is not a cached good title, it will return NULL.
+ * @param LinkTarget $target
+ * @param string $field ('length','redirect','revision','model')
+ * @return string|int|null
+ */
+ public function getGoodLinkFieldObj( LinkTarget $target, $field ) {
+ $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
+ $info = $this->mGoodLinks->get( $dbkey );
+ if ( !$info ) {
+ return null;
+ }
+ return $info[$field];
+ }
+
+ /**
+ * @param string $title Prefixed DB key
+ * @return bool
+ */
+ public function isBadLink( $title ) {
+ // Use get() to ensure it records as used for LRU.
+ return $this->mBadLinks->get( $title ) !== false;
+ }
+
+ /**
+ * Add a link for the title to the link cache
+ *
+ * @param int $id Page's ID
+ * @param LinkTarget $target
+ * @param int $len Text's length
+ * @param int $redir Whether the page is a redirect
+ * @param int $revision Latest revision's ID
+ * @param string|null $model Latest revision's content model ID
+ * @param string|null $lang Language code of the page, if not the content language
+ */
+ public function addGoodLinkObj( $id, LinkTarget $target, $len = -1, $redir = null,
+ $revision = 0, $model = null, $lang = null
+ ) {
+ $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
+ $this->mGoodLinks->set( $dbkey, [
+ 'id' => (int)$id,
+ 'length' => (int)$len,
+ 'redirect' => (int)$redir,
+ 'revision' => (int)$revision,
+ 'model' => $model ? (string)$model : null,
+ 'lang' => $lang ? (string)$lang : null,
+ ] );
+ }
+
+ /**
+ * Same as above with better interface.
+ * @since 1.19
+ * @param LinkTarget $target
+ * @param stdClass $row Object which has the fields page_id, page_is_redirect,
+ * page_latest and page_content_model
+ */
+ public function addGoodLinkObjFromRow( LinkTarget $target, $row ) {
+ $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
+ $this->mGoodLinks->set( $dbkey, [
+ 'id' => intval( $row->page_id ),
+ 'length' => intval( $row->page_len ),
+ 'redirect' => intval( $row->page_is_redirect ),
+ 'revision' => intval( $row->page_latest ),
+ 'model' => !empty( $row->page_content_model ) ? strval( $row->page_content_model ) : null,
+ 'lang' => !empty( $row->page_lang ) ? strval( $row->page_lang ) : null,
+ ] );
+ }
+
+ /**
+ * @param LinkTarget $target
+ */
+ public function addBadLinkObj( LinkTarget $target ) {
+ $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
+ if ( !$this->isBadLink( $dbkey ) ) {
+ $this->mBadLinks->set( $dbkey, 1 );
+ }
+ }
+
+ /**
+ * @param string $title Prefixed DB key
+ */
+ public function clearBadLink( $title ) {
+ $this->mBadLinks->delete( $title );
+ }
+
+ /**
+ * @param LinkTarget $target
+ */
+ public function clearLink( LinkTarget $target ) {
+ $dbkey = $this->titleFormatter->getPrefixedDBkey( $target );
+ $this->mBadLinks->delete( $dbkey );
+ $this->mGoodLinks->delete( $dbkey );
+ }
+
+ /**
+ * Add a title to the link cache, return the page_id or zero if non-existent
+ *
+ * @deprecated since 1.27, unused
+ * @param string $title Prefixed DB key
+ * @return int Page ID or zero
+ */
+ public function addLink( $title ) {
+ $nt = Title::newFromDBkey( $title );
+ if ( !$nt ) {
+ return 0;
+ }
+ return $this->addLinkObj( $nt );
+ }
+
+ /**
+ * Fields that LinkCache needs to select
+ *
+ * @since 1.28
+ * @return array
+ */
+ public static function getSelectFields() {
+ global $wgContentHandlerUseDB, $wgPageLanguageUseDB;
+
+ $fields = [ 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ];
+ if ( $wgContentHandlerUseDB ) {
+ $fields[] = 'page_content_model';
+ }
+ if ( $wgPageLanguageUseDB ) {
+ $fields[] = 'page_lang';
+ }
+
+ return $fields;
+ }
+
+ /**
+ * Add a title to the link cache, return the page_id or zero if non-existent
+ *
+ * @param LinkTarget $nt LinkTarget object to add
+ * @return int Page ID or zero
+ */
+ public function addLinkObj( LinkTarget $nt ) {
+ $key = $this->titleFormatter->getPrefixedDBkey( $nt );
+ if ( $this->isBadLink( $key ) || $nt->isExternal()
+ || $nt->inNamespace( NS_SPECIAL )
+ ) {
+ return 0;
+ }
+ $id = $this->getGoodLinkID( $key );
+ if ( $id != 0 ) {
+ return $id;
+ }
+
+ if ( $key === '' ) {
+ return 0;
+ }
+
+ // Cache template/file pages as they are less often viewed but heavily used
+ if ( $this->mForUpdate ) {
+ $row = $this->fetchPageRow( wfGetDB( DB_MASTER ), $nt );
+ } elseif ( $this->isCacheable( $nt ) ) {
+ // These pages are often transcluded heavily, so cache them
+ $cache = $this->wanCache;
+ $row = $cache->getWithSetCallback(
+ $cache->makeKey( 'page', $nt->getNamespace(), sha1( $nt->getDBkey() ) ),
+ $cache::TTL_DAY,
+ function ( $curValue, &$ttl, array &$setOpts ) use ( $cache, $nt ) {
+ $dbr = wfGetDB( DB_REPLICA );
+ $setOpts += Database::getCacheSetOptions( $dbr );
+
+ $row = $this->fetchPageRow( $dbr, $nt );
+ $mtime = $row ? wfTimestamp( TS_UNIX, $row->page_touched ) : false;
+ $ttl = $cache->adaptiveTTL( $mtime, $ttl );
+
+ return $row;
+ }
+ );
+ } else {
+ $row = $this->fetchPageRow( wfGetDB( DB_REPLICA ), $nt );
+ }
+
+ if ( $row ) {
+ $this->addGoodLinkObjFromRow( $nt, $row );
+ $id = intval( $row->page_id );
+ } else {
+ $this->addBadLinkObj( $nt );
+ $id = 0;
+ }
+
+ return $id;
+ }
+
+ /**
+ * @param WANObjectCache $cache
+ * @param TitleValue $t
+ * @return string[]
+ * @since 1.28
+ */
+ public function getMutableCacheKeys( WANObjectCache $cache, TitleValue $t ) {
+ if ( $this->isCacheable( $t ) ) {
+ return [ $cache->makeKey( 'page', $t->getNamespace(), sha1( $t->getDBkey() ) ) ];
+ }
+
+ return [];
+ }
+
+ private function isCacheable( LinkTarget $title ) {
+ return ( $title->inNamespace( NS_TEMPLATE ) || $title->inNamespace( NS_FILE ) );
+ }
+
+ private function fetchPageRow( IDatabase $db, LinkTarget $nt ) {
+ $fields = self::getSelectFields();
+ if ( $this->isCacheable( $nt ) ) {
+ $fields[] = 'page_touched';
+ }
+
+ return $db->selectRow(
+ 'page',
+ $fields,
+ [ 'page_namespace' => $nt->getNamespace(), 'page_title' => $nt->getDBkey() ],
+ __METHOD__
+ );
+ }
+
+ /**
+ * Purge the link cache for a title
+ *
+ * @param LinkTarget $title
+ * @since 1.28
+ */
+ public function invalidateTitle( LinkTarget $title ) {
+ if ( $this->isCacheable( $title ) ) {
+ $cache = ObjectCache::getMainWANInstance();
+ $cache->delete(
+ $cache->makeKey( 'page', $title->getNamespace(), sha1( $title->getDBkey() ) )
+ );
+ }
+ }
+
+ /**
+ * Clears cache
+ */
+ public function clear() {
+ $this->mGoodLinks->clear();
+ $this->mBadLinks->clear();
+ }
+}
scripts.mit.edu / autoinstallsdev / mediawiki.git / blobdiff