3 * InterwikiLookup implementing the "classic" interwiki storage (hardcoded up to MW 1.26).
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 * http://www.gnu.org/copyleft/gpl.html
23 namespace MediaWiki\Interwiki
;
25 use Cdb\Exception
as CdbException
;
26 use Cdb\Reader
as CdbReader
;
32 use Wikimedia\Rdbms\Database
;
35 * InterwikiLookup implementing the "classic" interwiki storage (hardcoded up to MW 1.26).
37 * This implements two levels of caching (in-process array and a WANObjectCache)
38 * and tree storage backends (SQL, CDB, and plain PHP arrays).
40 * All information is loaded on creation when called by $this->fetch( $prefix ).
41 * All work is done on replica DB, because this should *never* change (except during
42 * schema updates etc, which aren't wiki-related)
46 class ClassicInterwikiLookup
implements InterwikiLookup
{
56 private $contentLanguage;
66 private $objectCacheExpiry;
69 * @var bool|array|string
76 private $interwikiScopes;
81 private $fallbackSite;
86 private $cdbReader = null;
91 private $thisSite = null;
94 * @param Language $contentLanguage Language object used to convert prefixes to lower case
95 * @param WANObjectCache $objectCache Cache for interwiki info retrieved from the database
96 * @param int $objectCacheExpiry Expiry time for $objectCache, in seconds
97 * @param bool|array|string $cdbData The path of a CDB file, or
98 * an array resembling the contents of a CDB file,
99 * or false to use the database.
100 * @param int $interwikiScopes Specify number of domains to check for messages:
101 * - 1: Just local wiki level
102 * - 2: wiki and global levels
103 * - 3: site level as well as wiki and global levels
104 * @param string $fallbackSite The code to assume for the local site,
106 function __construct(
107 Language
$contentLanguage,
108 WANObjectCache
$objectCache,
114 $this->localCache
= new MapCacheLRU( 100 );
116 $this->contentLanguage
= $contentLanguage;
117 $this->objectCache
= $objectCache;
118 $this->objectCacheExpiry
= $objectCacheExpiry;
119 $this->cdbData
= $cdbData;
120 $this->interwikiScopes
= $interwikiScopes;
121 $this->fallbackSite
= $fallbackSite;
125 * Check whether an interwiki prefix exists
127 * @param string $prefix Interwiki prefix to use
128 * @return bool Whether it exists
130 public function isValidInterwiki( $prefix ) {
131 $result = $this->fetch( $prefix );
133 return (bool)$result;
137 * Fetch an Interwiki object
139 * @param string $prefix Interwiki prefix to use
140 * @return Interwiki|null|bool
142 public function fetch( $prefix ) {
143 if ( $prefix == '' ) {
147 $prefix = $this->contentLanguage
->lc( $prefix );
148 if ( $this->localCache
->has( $prefix ) ) {
149 return $this->localCache
->get( $prefix );
152 if ( $this->cdbData
) {
153 $iw = $this->getInterwikiCached( $prefix );
155 $iw = $this->load( $prefix );
160 $this->localCache
->set( $prefix, $iw );
166 * Resets locally cached Interwiki objects. This is intended for use during testing only.
167 * This does not invalidate entries in the persistent cache, as invalidateCache() does.
170 public function resetLocalCache() {
171 $this->localCache
->clear();
175 * Purge the in-process and object cache for an interwiki prefix
176 * @param string $prefix
178 public function invalidateCache( $prefix ) {
179 $this->localCache
->clear( $prefix );
181 $key = $this->objectCache
->makeKey( 'interwiki', $prefix );
182 $this->objectCache
->delete( $key );
186 * Fetch interwiki prefix data from local cache in constant database.
188 * @note More logic is explained in DefaultSettings.
190 * @param string $prefix Interwiki prefix
191 * @return Interwiki|false
193 private function getInterwikiCached( $prefix ) {
194 $value = $this->getInterwikiCacheEntry( $prefix );
198 list( $local, $url ) = explode( ' ', $value, 2 );
199 return new Interwiki( $prefix, $url, '', '', (int)$local );
206 * Get entry from interwiki cache
208 * @note More logic is explained in DefaultSettings.
210 * @param string $prefix Database key
211 * @return bool|string The interwiki entry or false if not found
213 private function getInterwikiCacheEntry( $prefix ) {
214 wfDebug( __METHOD__
. "( $prefix )\n" );
218 if ( $this->interwikiScopes
>= 3 && !$this->thisSite
) {
219 $this->thisSite
= $this->getCacheValue( '__sites:' . wfWikiID() );
220 if ( $this->thisSite
== '' ) {
221 $this->thisSite
= $this->fallbackSite
;
225 $value = $this->getCacheValue( wfWikiID() . ':' . $prefix );
227 if ( $value == '' && $this->interwikiScopes
>= 3 ) {
228 $value = $this->getCacheValue( "_{$this->thisSite}:{$prefix}" );
231 if ( $value == '' && $this->interwikiScopes
>= 2 ) {
232 $value = $this->getCacheValue( "__global:{$prefix}" );
234 if ( $value == 'undef' ) {
237 } catch ( CdbException
$e ) {
238 wfDebug( __METHOD__
. ": CdbException caught, error message was "
239 . $e->getMessage() );
245 private function getCacheValue( $key ) {
246 if ( $this->cdbReader
=== null ) {
247 if ( is_string( $this->cdbData
) ) {
248 $this->cdbReader
= \Cdb\Reader
::open( $this->cdbData
);
249 } elseif ( is_array( $this->cdbData
) ) {
250 $this->cdbReader
= new \Cdb\Reader\
Hash( $this->cdbData
);
252 $this->cdbReader
= false;
256 if ( $this->cdbReader
) {
257 return $this->cdbReader
->get( $key );
264 * Load the interwiki, trying first memcached then the DB
266 * @param string $prefix The interwiki prefix
267 * @return Interwiki|bool Interwiki if $prefix is valid, otherwise false
269 private function load( $prefix ) {
271 if ( !Hooks
::run( 'InterwikiLoadPrefix', [ $prefix, &$iwData ] ) ) {
272 return $this->loadFromArray( $iwData );
275 if ( is_array( $iwData ) ) {
276 $iw = $this->loadFromArray( $iwData );
278 return $iw; // handled by hook
282 $iwData = $this->objectCache
->getWithSetCallback(
283 $this->objectCache
->makeKey( 'interwiki', $prefix ),
284 $this->objectCacheExpiry
,
285 function ( $oldValue, &$ttl, array &$setOpts ) use ( $prefix ) {
286 $dbr = wfGetDB( DB_REPLICA
); // TODO: inject LoadBalancer
288 $setOpts +
= Database
::getCacheSetOptions( $dbr );
290 $row = $dbr->selectRow(
292 self
::selectFields(),
293 [ 'iw_prefix' => $prefix ],
297 return $row ?
(array)$row : '!NONEXISTENT';
301 if ( is_array( $iwData ) ) {
302 return $this->loadFromArray( $iwData ) ?
: false;
309 * Fill in member variables from an array (e.g. memcached result, Database::fetchRow, etc)
311 * @param array $mc Associative array: row from the interwiki table
312 * @return Interwiki|bool Interwiki object or false if $mc['iw_url'] is not set
314 private function loadFromArray( $mc ) {
315 if ( isset( $mc['iw_url'] ) ) {
316 $url = $mc['iw_url'];
317 $local = isset( $mc['iw_local'] ) ?
$mc['iw_local'] : 0;
318 $trans = isset( $mc['iw_trans'] ) ?
$mc['iw_trans'] : 0;
319 $api = isset( $mc['iw_api'] ) ?
$mc['iw_api'] : '';
320 $wikiId = isset( $mc['iw_wikiid'] ) ?
$mc['iw_wikiid'] : '';
322 return new Interwiki( null, $url, $api, $wikiId, $local, $trans );
329 * Fetch all interwiki prefixes from interwiki cache
331 * @param null|string $local If not null, limits output to local/non-local interwikis
332 * @return array List of prefixes, where each row is an associative array
334 private function getAllPrefixesCached( $local ) {
335 wfDebug( __METHOD__
. "()\n" );
338 /* Resolve site name */
339 if ( $this->interwikiScopes
>= 3 && !$this->thisSite
) {
340 $site = $this->getCacheValue( '__sites:' . wfWikiID() );
343 $this->thisSite
= $this->fallbackSite
;
345 $this->thisSite
= $site;
349 // List of interwiki sources
352 if ( $this->interwikiScopes
>= 2 ) {
353 $sources[] = '__global';
356 if ( $this->interwikiScopes
>= 3 ) {
357 $sources[] = '_' . $this->thisSite
;
359 $sources[] = wfWikiID();
361 foreach ( $sources as $source ) {
362 $list = $this->getCacheValue( '__list:' . $source );
363 foreach ( explode( ' ', $list ) as $iw_prefix ) {
364 $row = $this->getCacheValue( "{$source}:{$iw_prefix}" );
369 list( $iw_local, $iw_url ) = explode( ' ', $row );
371 if ( $local !== null && $local != $iw_local ) {
375 $data[$iw_prefix] = [
376 'iw_prefix' => $iw_prefix,
378 'iw_local' => $iw_local,
382 } catch ( CdbException
$e ) {
383 wfDebug( __METHOD__
. ": CdbException caught, error message was "
384 . $e->getMessage() );
387 return array_values( $data );
391 * Fetch all interwiki prefixes from DB
393 * @param string|null $local If not null, limits output to local/non-local interwikis
394 * @return array[] Interwiki rows
396 private function getAllPrefixesDB( $local ) {
397 $db = wfGetDB( DB_REPLICA
); // TODO: inject DB LoadBalancer
401 if ( $local !== null ) {
403 $where['iw_local'] = 1;
404 } elseif ( $local == 0 ) {
405 $where['iw_local'] = 0;
409 $res = $db->select( 'interwiki',
410 self
::selectFields(),
411 $where, __METHOD__
, [ 'ORDER BY' => 'iw_prefix' ]
415 foreach ( $res as $row ) {
416 $retval[] = (array)$row;
423 * Returns all interwiki prefixes
425 * @param string|null $local If set, limits output to local/non-local interwikis
426 * @return array[] Interwiki rows, where each row is an associative array
428 public function getAllPrefixes( $local = null ) {
429 if ( $this->cdbData
) {
430 return $this->getAllPrefixesCached( $local );
433 return $this->getAllPrefixesDB( $local );
437 * Return the list of interwiki fields that should be selected to create
438 * a new Interwiki object.
441 private static function selectFields() {