--- /dev/null
+<?php
+namespace MediaWiki\Interwiki;
+
+/**
+ * InterwikiLookup implementing the "classic" interwiki storage (hardcoded up to MW 1.26).
+ *
+ * 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
+ */
+use \Cdb\Exception as CdbException;
+use \Cdb\Reader as CdbReader;
+use Wikimedia\Rdbms\Database;
+use Hooks;
+use Interwiki;
+use Language;
+use MapCacheLRU;
+use WANObjectCache;
+
+/**
+ * InterwikiLookup implementing the "classic" interwiki storage (hardcoded up to MW 1.26).
+ *
+ * This implements two levels of caching (in-process array and a WANObjectCache)
+ * and tree storage backends (SQL, CDB, and plain PHP arrays).
+ *
+ * All information is loaded on creation when called by $this->fetch( $prefix ).
+ * All work is done on replica DB, because this should *never* change (except during
+ * schema updates etc, which aren't wiki-related)
+ *
+ * @since 1.28
+ */
+class ClassicInterwikiLookup implements InterwikiLookup {
+
+ /**
+ * @var MapCacheLRU
+ */
+ private $localCache;
+
+ /**
+ * @var Language
+ */
+ private $contentLanguage;
+
+ /**
+ * @var WANObjectCache
+ */
+ private $objectCache;
+
+ /**
+ * @var int
+ */
+ private $objectCacheExpiry;
+
+ /**
+ * @var bool|array|string
+ */
+ private $cdbData;
+
+ /**
+ * @var int
+ */
+ private $interwikiScopes;
+
+ /**
+ * @var string
+ */
+ private $fallbackSite;
+
+ /**
+ * @var CdbReader|null
+ */
+ private $cdbReader = null;
+
+ /**
+ * @var string|null
+ */
+ private $thisSite = null;
+
+ /**
+ * @param Language $contentLanguage Language object used to convert prefixes to lower case
+ * @param WANObjectCache $objectCache Cache for interwiki info retrieved from the database
+ * @param int $objectCacheExpiry Expiry time for $objectCache, in seconds
+ * @param bool|array|string $cdbData The path of a CDB file, or
+ * an array resembling the contents of a CDB file,
+ * or false to use the database.
+ * @param int $interwikiScopes Specify number of domains to check for messages:
+ * - 1: Just local wiki level
+ * - 2: wiki and global levels
+ * - 3: site level as well as wiki and global levels
+ * @param string $fallbackSite The code to assume for the local site,
+ */
+ function __construct(
+ Language $contentLanguage,
+ WANObjectCache $objectCache,
+ $objectCacheExpiry,
+ $cdbData,
+ $interwikiScopes,
+ $fallbackSite
+ ) {
+ $this->localCache = new MapCacheLRU( 100 );
+
+ $this->contentLanguage = $contentLanguage;
+ $this->objectCache = $objectCache;
+ $this->objectCacheExpiry = $objectCacheExpiry;
+ $this->cdbData = $cdbData;
+ $this->interwikiScopes = $interwikiScopes;
+ $this->fallbackSite = $fallbackSite;
+ }
+
+ /**
+ * Check whether an interwiki prefix exists
+ *
+ * @param string $prefix Interwiki prefix to use
+ * @return bool Whether it exists
+ */
+ public function isValidInterwiki( $prefix ) {
+ $result = $this->fetch( $prefix );
+
+ return (bool)$result;
+ }
+
+ /**
+ * Fetch an Interwiki object
+ *
+ * @param string $prefix Interwiki prefix to use
+ * @return Interwiki|null|bool
+ */
+ public function fetch( $prefix ) {
+ if ( $prefix == '' ) {
+ return null;
+ }
+
+ $prefix = $this->contentLanguage->lc( $prefix );
+ if ( $this->localCache->has( $prefix ) ) {
+ return $this->localCache->get( $prefix );
+ }
+
+ if ( $this->cdbData ) {
+ $iw = $this->getInterwikiCached( $prefix );
+ } else {
+ $iw = $this->load( $prefix );
+ if ( !$iw ) {
+ $iw = false;
+ }
+ }
+ $this->localCache->set( $prefix, $iw );
+
+ return $iw;
+ }
+
+ /**
+ * Resets locally cached Interwiki objects. This is intended for use during testing only.
+ * This does not invalidate entries in the persistent cache, as invalidateCache() does.
+ * @since 1.27
+ */
+ public function resetLocalCache() {
+ $this->localCache->clear();
+ }
+
+ /**
+ * Purge the in-process and object cache for an interwiki prefix
+ * @param string $prefix
+ */
+ public function invalidateCache( $prefix ) {
+ $this->localCache->clear( $prefix );
+
+ $key = $this->objectCache->makeKey( 'interwiki', $prefix );
+ $this->objectCache->delete( $key );
+ }
+
+ /**
+ * Fetch interwiki prefix data from local cache in constant database.
+ *
+ * @note More logic is explained in DefaultSettings.
+ *
+ * @param string $prefix Interwiki prefix
+ * @return Interwiki|false
+ */
+ private function getInterwikiCached( $prefix ) {
+ $value = $this->getInterwikiCacheEntry( $prefix );
+
+ if ( $value ) {
+ // Split values
+ list( $local, $url ) = explode( ' ', $value, 2 );
+ return new Interwiki( $prefix, $url, '', '', (int)$local );
+ } else {
+ return false;
+ }
+ }
+
+ /**
+ * Get entry from interwiki cache
+ *
+ * @note More logic is explained in DefaultSettings.
+ *
+ * @param string $prefix Database key
+ * @return bool|string The interwiki entry or false if not found
+ */
+ private function getInterwikiCacheEntry( $prefix ) {
+ wfDebug( __METHOD__ . "( $prefix )\n" );
+ $value = false;
+ try {
+ // Resolve site name
+ if ( $this->interwikiScopes >= 3 && !$this->thisSite ) {
+ $this->thisSite = $this->getCacheValue( '__sites:' . wfWikiID() );
+ if ( $this->thisSite == '' ) {
+ $this->thisSite = $this->fallbackSite;
+ }
+ }
+
+ $value = $this->getCacheValue( wfWikiID() . ':' . $prefix );
+ // Site level
+ if ( $value == '' && $this->interwikiScopes >= 3 ) {
+ $value = $this->getCacheValue( "_{$this->thisSite}:{$prefix}" );
+ }
+ // Global Level
+ if ( $value == '' && $this->interwikiScopes >= 2 ) {
+ $value = $this->getCacheValue( "__global:{$prefix}" );
+ }
+ if ( $value == 'undef' ) {
+ $value = '';
+ }
+ } catch ( CdbException $e ) {
+ wfDebug( __METHOD__ . ": CdbException caught, error message was "
+ . $e->getMessage() );
+ }
+
+ return $value;
+ }
+
+ private function getCacheValue( $key ) {
+ if ( $this->cdbReader === null ) {
+ if ( is_string( $this->cdbData ) ) {
+ $this->cdbReader = \Cdb\Reader::open( $this->cdbData );
+ } elseif ( is_array( $this->cdbData ) ) {
+ $this->cdbReader = new \Cdb\Reader\Hash( $this->cdbData );
+ } else {
+ $this->cdbReader = false;
+ }
+ }
+
+ if ( $this->cdbReader ) {
+ return $this->cdbReader->get( $key );
+ } else {
+ return false;
+ }
+ }
+
+ /**
+ * Load the interwiki, trying first memcached then the DB
+ *
+ * @param string $prefix The interwiki prefix
+ * @return Interwiki|bool Interwiki if $prefix is valid, otherwise false
+ */
+ private function load( $prefix ) {
+ $iwData = [];
+ if ( !Hooks::run( 'InterwikiLoadPrefix', [ $prefix, &$iwData ] ) ) {
+ return $this->loadFromArray( $iwData );
+ }
+
+ if ( is_array( $iwData ) ) {
+ $iw = $this->loadFromArray( $iwData );
+ if ( $iw ) {
+ return $iw; // handled by hook
+ }
+ }
+
+ $iwData = $this->objectCache->getWithSetCallback(
+ $this->objectCache->makeKey( 'interwiki', $prefix ),
+ $this->objectCacheExpiry,
+ function ( $oldValue, &$ttl, array &$setOpts ) use ( $prefix ) {
+ $dbr = wfGetDB( DB_REPLICA ); // TODO: inject LoadBalancer
+
+ $setOpts += Database::getCacheSetOptions( $dbr );
+
+ $row = $dbr->selectRow(
+ 'interwiki',
+ self::selectFields(),
+ [ 'iw_prefix' => $prefix ],
+ __METHOD__
+ );
+
+ return $row ? (array)$row : '!NONEXISTENT';
+ }
+ );
+
+ if ( is_array( $iwData ) ) {
+ return $this->loadFromArray( $iwData ) ?: false;
+ }
+
+ return false;
+ }
+
+ /**
+ * Fill in member variables from an array (e.g. memcached result, Database::fetchRow, etc)
+ *
+ * @param array $mc Associative array: row from the interwiki table
+ * @return Interwiki|bool Interwiki object or false if $mc['iw_url'] is not set
+ */
+ private function loadFromArray( $mc ) {
+ if ( isset( $mc['iw_url'] ) ) {
+ $url = $mc['iw_url'];
+ $local = isset( $mc['iw_local'] ) ? $mc['iw_local'] : 0;
+ $trans = isset( $mc['iw_trans'] ) ? $mc['iw_trans'] : 0;
+ $api = isset( $mc['iw_api'] ) ? $mc['iw_api'] : '';
+ $wikiId = isset( $mc['iw_wikiid'] ) ? $mc['iw_wikiid'] : '';
+
+ return new Interwiki( null, $url, $api, $wikiId, $local, $trans );
+ }
+
+ return false;
+ }
+
+ /**
+ * Fetch all interwiki prefixes from interwiki cache
+ *
+ * @param null|string $local If not null, limits output to local/non-local interwikis
+ * @return array List of prefixes, where each row is an associative array
+ */
+ private function getAllPrefixesCached( $local ) {
+ wfDebug( __METHOD__ . "()\n" );
+ $data = [];
+ try {
+ /* Resolve site name */
+ if ( $this->interwikiScopes >= 3 && !$this->thisSite ) {
+ $site = $this->getCacheValue( '__sites:' . wfWikiID() );
+
+ if ( $site == '' ) {
+ $this->thisSite = $this->fallbackSite;
+ } else {
+ $this->thisSite = $site;
+ }
+ }
+
+ // List of interwiki sources
+ $sources = [];
+ // Global Level
+ if ( $this->interwikiScopes >= 2 ) {
+ $sources[] = '__global';
+ }
+ // Site level
+ if ( $this->interwikiScopes >= 3 ) {
+ $sources[] = '_' . $this->thisSite;
+ }
+ $sources[] = wfWikiID();
+
+ foreach ( $sources as $source ) {
+ $list = $this->getCacheValue( '__list:' . $source );
+ foreach ( explode( ' ', $list ) as $iw_prefix ) {
+ $row = $this->getCacheValue( "{$source}:{$iw_prefix}" );
+ if ( !$row ) {
+ continue;
+ }
+
+ list( $iw_local, $iw_url ) = explode( ' ', $row );
+
+ if ( $local !== null && $local != $iw_local ) {
+ continue;
+ }
+
+ $data[$iw_prefix] = [
+ 'iw_prefix' => $iw_prefix,
+ 'iw_url' => $iw_url,
+ 'iw_local' => $iw_local,
+ ];
+ }
+ }
+ } catch ( CdbException $e ) {
+ wfDebug( __METHOD__ . ": CdbException caught, error message was "
+ . $e->getMessage() );
+ }
+
+ return array_values( $data );
+ }
+
+ /**
+ * Fetch all interwiki prefixes from DB
+ *
+ * @param string|null $local If not null, limits output to local/non-local interwikis
+ * @return array[] Interwiki rows
+ */
+ private function getAllPrefixesDB( $local ) {
+ $db = wfGetDB( DB_REPLICA ); // TODO: inject DB LoadBalancer
+
+ $where = [];
+
+ if ( $local !== null ) {
+ if ( $local == 1 ) {
+ $where['iw_local'] = 1;
+ } elseif ( $local == 0 ) {
+ $where['iw_local'] = 0;
+ }
+ }
+
+ $res = $db->select( 'interwiki',
+ self::selectFields(),
+ $where, __METHOD__, [ 'ORDER BY' => 'iw_prefix' ]
+ );
+
+ $retval = [];
+ foreach ( $res as $row ) {
+ $retval[] = (array)$row;
+ }
+
+ return $retval;
+ }
+
+ /**
+ * Returns all interwiki prefixes
+ *
+ * @param string|null $local If set, limits output to local/non-local interwikis
+ * @return array[] Interwiki rows, where each row is an associative array
+ */
+ public function getAllPrefixes( $local = null ) {
+ if ( $this->cdbData ) {
+ return $this->getAllPrefixesCached( $local );
+ }
+
+ return $this->getAllPrefixesDB( $local );
+ }
+
+ /**
+ * Return the list of interwiki fields that should be selected to create
+ * a new Interwiki object.
+ * @return string[]
+ */
+ private static function selectFields() {
+ return [
+ 'iw_prefix',
+ 'iw_url',
+ 'iw_api',
+ 'iw_wikiid',
+ 'iw_local',
+ 'iw_trans'
+ ];
+ }
+
+}
scripts.mit.edu / autoinstallsdev / mediawiki.git / blobdiff