3 * Localisation messages cache.
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 use MediaWiki\MediaWikiServices
;
24 use Wikimedia\ScopedCallback
;
25 use MediaWiki\Logger\LoggerFactory
;
26 use Wikimedia\Rdbms\Database
;
29 * MediaWiki message cache structure version.
30 * Bump this whenever the message cache format has changed.
32 define( 'MSG_CACHE_VERSION', 2 );
35 * Cache of messages that are defined by MediaWiki namespace pages or by hooks
37 * Performs various MediaWiki namespace-related functions
41 const FOR_UPDATE
= 1; // force message reload
43 /** How long to wait for memcached locks */
45 /** How long memcached locks last */
49 * Process cache of loaded messages that are defined in MediaWiki namespace
51 * @var MapCacheLRU Map of (language code => key => " <MESSAGE>" or "!TOO BIG")
56 * @var bool[] Map of (language code => boolean)
58 protected $cacheVolatile = [];
61 * Should mean that database cannot be used, but check
67 * Lifetime for cache, used by object caching.
68 * Set on construction, see __construct().
73 * Message cache has its own parser which it uses to transform messages
76 protected $mParserOptions;
81 * @var bool $mInParser
83 protected $mInParser = false;
85 /** @var WANObjectCache */
88 protected $clusterCache;
95 * @var MessageCache $instance
97 private static $instance;
100 * Get the signleton instance of this class
103 * @return MessageCache
105 public static function singleton() {
106 if ( self
::$instance === null ) {
107 global $wgUseDatabaseMessages, $wgMsgCacheExpiry, $wgUseLocalMessageCache;
108 self
::$instance = new self(
109 MediaWikiServices
::getInstance()->getMainWANObjectCache(),
110 wfGetMessageCacheStorage(),
111 $wgUseLocalMessageCache
112 ? MediaWikiServices
::getInstance()->getLocalServerObjectCache()
113 : new EmptyBagOStuff(),
114 $wgUseDatabaseMessages,
119 return self
::$instance;
123 * Destroy the singleton instance
127 public static function destroyInstance() {
128 self
::$instance = null;
132 * Normalize message key input
134 * @param string $key Input message key to be normalized
135 * @return string Normalized message key
137 public static function normalizeKey( $key ) {
140 $lckey = strtr( $key, ' ', '_' );
141 if ( ord( $lckey ) < 128 ) {
142 $lckey[0] = strtolower( $lckey[0] );
144 $lckey = $wgContLang->lcfirst( $lckey );
151 * @param WANObjectCache $wanCache
152 * @param BagOStuff $clusterCache
153 * @param BagOStuff $serverCache
154 * @param bool $useDB Whether to look for message overrides (e.g. MediaWiki: pages)
155 * @param int $expiry Lifetime for cache. @see $mExpiry.
157 public function __construct(
158 WANObjectCache
$wanCache,
159 BagOStuff
$clusterCache,
160 BagOStuff
$serverCache,
164 $this->wanCache
= $wanCache;
165 $this->clusterCache
= $clusterCache;
166 $this->srvCache
= $serverCache;
168 $this->cache
= new MapCacheLRU( 5 ); // limit size for sanity
170 $this->mDisable
= !$useDB;
171 $this->mExpiry
= $expiry;
175 * ParserOptions is lazy initialised.
177 * @return ParserOptions
179 function getParserOptions() {
182 if ( !$this->mParserOptions
) {
183 if ( !$wgUser->isSafeToLoad() ) {
184 // $wgUser isn't unstubbable yet, so don't try to get a
185 // ParserOptions for it. And don't cache this ParserOptions
187 $po = ParserOptions
::newFromAnon();
188 $po->setAllowUnsafeRawHtml( false );
192 $this->mParserOptions
= new ParserOptions
;
193 // Messages may take parameters that could come
194 // from malicious sources. As a precaution, disable
195 // the <html> parser tag when parsing messages.
196 $this->mParserOptions
->setAllowUnsafeRawHtml( false );
199 return $this->mParserOptions
;
203 * Try to load the cache from APC.
205 * @param string $code Optional language code, see documenation of load().
206 * @return array|bool The cache array, or false if not in cache.
208 protected function getLocalCache( $code ) {
209 $cacheKey = $this->srvCache
->makeKey( __CLASS__
, $code );
211 return $this->srvCache
->get( $cacheKey );
215 * Save the cache to APC.
217 * @param string $code
218 * @param array $cache The cache array
220 protected function saveToLocalCache( $code, $cache ) {
221 $cacheKey = $this->srvCache
->makeKey( __CLASS__
, $code );
222 $this->srvCache
->set( $cacheKey, $cache );
226 * Loads messages from caches or from database in this order:
227 * (1) local message cache (if $wgUseLocalMessageCache is enabled)
229 * (3) from the database.
231 * When succesfully loading from (2) or (3), all higher level caches are
232 * updated for the newest version.
234 * Nothing is loaded if member variable mDisable is true, either manually
235 * set by calling code or if message loading fails (is this possible?).
237 * Returns true if cache is already populated or it was succesfully populated,
238 * or false if populating empty cache fails. Also returns true if MessageCache
241 * @param string $code Language to which load messages
242 * @param int|null $mode Use MessageCache::FOR_UPDATE to skip process cache [optional]
243 * @throws InvalidArgumentException
246 protected function load( $code, $mode = null ) {
247 if ( !is_string( $code ) ) {
248 throw new InvalidArgumentException( "Missing language code" );
251 # Don't do double loading...
252 if ( $this->cache
->has( $code ) && $mode != self
::FOR_UPDATE
) {
256 # 8 lines of code just to say (once) that message cache is disabled
257 if ( $this->mDisable
) {
258 static $shownDisabled = false;
259 if ( !$shownDisabled ) {
260 wfDebug( __METHOD__
. ": disabled\n" );
261 $shownDisabled = true;
267 # Loading code starts
268 $success = false; # Keep track of success
269 $staleCache = false; # a cache array with expired data, or false if none has been loaded
270 $where = []; # Debug info, delayed to avoid spamming debug log too much
272 # Hash of the contents is stored in memcache, to detect if data-center cache
273 # or local cache goes out of date (e.g. due to replace() on some other server)
274 list( $hash, $hashVolatile ) = $this->getValidationHash( $code );
275 $this->cacheVolatile
[$code] = $hashVolatile;
277 # Try the local cache and check against the cluster hash key...
278 $cache = $this->getLocalCache( $code );
280 $where[] = 'local cache is empty';
281 } elseif ( !isset( $cache['HASH'] ) ||
$cache['HASH'] !== $hash ) {
282 $where[] = 'local cache has the wrong hash';
283 $staleCache = $cache;
284 } elseif ( $this->isCacheExpired( $cache ) ) {
285 $where[] = 'local cache is expired';
286 $staleCache = $cache;
287 } elseif ( $hashVolatile ) {
288 $where[] = 'local cache validation key is expired/volatile';
289 $staleCache = $cache;
291 $where[] = 'got from local cache';
292 $this->cache
->set( $code, $cache );
297 $cacheKey = $this->clusterCache
->makeKey( 'messages', $code );
298 # Try the global cache. If it is empty, try to acquire a lock. If
299 # the lock can't be acquired, wait for the other thread to finish
300 # and then try the global cache a second time.
301 for ( $failedAttempts = 0; $failedAttempts <= 1; $failedAttempts++
) {
302 if ( $hashVolatile && $staleCache ) {
303 # Do not bother fetching the whole cache blob to avoid I/O.
304 # Instead, just try to get the non-blocking $statusKey lock
305 # below, and use the local stale value if it was not acquired.
306 $where[] = 'global cache is presumed expired';
308 $cache = $this->clusterCache
->get( $cacheKey );
310 $where[] = 'global cache is empty';
311 } elseif ( $this->isCacheExpired( $cache ) ) {
312 $where[] = 'global cache is expired';
313 $staleCache = $cache;
314 } elseif ( $hashVolatile ) {
315 # DB results are replica DB lag prone until the holdoff TTL passes.
316 # By then, updates should be reflected in loadFromDBWithLock().
317 # One thread renerates the cache while others use old values.
318 $where[] = 'global cache is expired/volatile';
319 $staleCache = $cache;
321 $where[] = 'got from global cache';
322 $this->cache
->set( $code, $cache );
323 $this->saveToCaches( $cache, 'local-only', $code );
329 # Done, no need to retry
333 # We need to call loadFromDB. Limit the concurrency to one process.
334 # This prevents the site from going down when the cache expires.
335 # Note that the DB slam protection lock here is non-blocking.
336 $loadStatus = $this->loadFromDBWithLock( $code, $where, $mode );
337 if ( $loadStatus === true ) {
340 } elseif ( $staleCache ) {
341 # Use the stale cache while some other thread constructs the new one
342 $where[] = 'using stale cache';
343 $this->cache
->set( $code, $staleCache );
346 } elseif ( $failedAttempts > 0 ) {
347 # Already blocked once, so avoid another lock/unlock cycle.
348 # This case will typically be hit if memcached is down, or if
349 # loadFromDB() takes longer than LOCK_WAIT.
350 $where[] = "could not acquire status key.";
352 } elseif ( $loadStatus === 'cantacquire' ) {
353 # Wait for the other thread to finish, then retry. Normally,
354 # the memcached get() will then yeild the other thread's result.
355 $where[] = 'waited for other thread to complete';
356 $this->getReentrantScopedLock( $cacheKey );
358 # Disable cache; $loadStatus is 'disabled'
365 $where[] = 'loading FAILED - cache is disabled';
366 $this->mDisable
= true;
367 $this->cache
->set( $code, null );
368 wfDebugLog( 'MessageCacheError', __METHOD__
. ": Failed to load $code\n" );
369 # This used to throw an exception, but that led to nasty side effects like
370 # the whole wiki being instantly down if the memcached server died
373 if ( !$this->cache
->has( $code ) ) { // sanity
374 throw new LogicException( "Process cache for '$code' should be set by now." );
377 $info = implode( ', ', $where );
378 wfDebugLog( 'MessageCache', __METHOD__
. ": Loading $code... $info\n" );
384 * @param string $code
385 * @param array &$where List of wfDebug() comments
386 * @param int|null $mode Use MessageCache::FOR_UPDATE to use DB_MASTER
387 * @return bool|string True on success or one of ("cantacquire", "disabled")
389 protected function loadFromDBWithLock( $code, array &$where, $mode = null ) {
390 # If cache updates on all levels fail, give up on message overrides.
391 # This is to avoid easy site outages; see $saveSuccess comments below.
392 $statusKey = $this->clusterCache
->makeKey( 'messages', $code, 'status' );
393 $status = $this->clusterCache
->get( $statusKey );
394 if ( $status === 'error' ) {
395 $where[] = "could not load; method is still globally disabled";
399 # Now let's regenerate
400 $where[] = 'loading from database';
402 # Lock the cache to prevent conflicting writes.
403 # This lock is non-blocking so stale cache can quickly be used.
404 # Note that load() will call a blocking getReentrantScopedLock()
405 # after this if it really need to wait for any current thread.
406 $cacheKey = $this->clusterCache
->makeKey( 'messages', $code );
407 $scopedLock = $this->getReentrantScopedLock( $cacheKey, 0 );
408 if ( !$scopedLock ) {
409 $where[] = 'could not acquire main lock';
410 return 'cantacquire';
413 $cache = $this->loadFromDB( $code, $mode );
414 $this->cache
->set( $code, $cache );
415 $saveSuccess = $this->saveToCaches( $cache, 'all', $code );
417 if ( !$saveSuccess ) {
419 * Cache save has failed.
421 * There are two main scenarios where this could be a problem:
422 * - The cache is more than the maximum size (typically 1MB compressed).
423 * - Memcached has no space remaining in the relevant slab class. This is
424 * unlikely with recent versions of memcached.
426 * Either way, if there is a local cache, nothing bad will happen. If there
427 * is no local cache, disabling the message cache for all requests avoids
428 * incurring a loadFromDB() overhead on every request, and thus saves the
429 * wiki from complete downtime under moderate traffic conditions.
431 if ( $this->srvCache
instanceof EmptyBagOStuff
) {
432 $this->clusterCache
->set( $statusKey, 'error', 60 * 5 );
433 $where[] = 'could not save cache, disabled globally for 5 minutes';
435 $where[] = "could not save global cache";
443 * Loads cacheable messages from the database. Messages bigger than
444 * $wgMaxMsgCacheEntrySize are assigned a special value, and are loaded
445 * on-demand from the database later.
447 * @param string $code Language code
448 * @param int|null $mode Use MessageCache::FOR_UPDATE to skip process cache
449 * @return array Loaded messages for storing in caches
451 protected function loadFromDB( $code, $mode = null ) {
452 global $wgMaxMsgCacheEntrySize, $wgLanguageCode, $wgAdaptiveMessageCache;
454 // (T164666) The query here performs really poorly on WMF's
455 // contributions replicas. We don't have a way to say "any group except
456 // contributions", so for the moment let's specify 'api'.
457 // @todo: Get rid of this hack.
458 $dbr = wfGetDB( ( $mode == self
::FOR_UPDATE
) ? DB_MASTER
: DB_REPLICA
, 'api' );
464 'page_is_redirect' => 0,
465 'page_namespace' => NS_MEDIAWIKI
,
469 if ( $wgAdaptiveMessageCache && $code !== $wgLanguageCode ) {
470 if ( !$this->cache
->has( $wgLanguageCode ) ) {
471 $this->load( $wgLanguageCode );
473 $mostused = array_keys( $this->cache
->get( $wgLanguageCode ) );
474 foreach ( $mostused as $key => $value ) {
475 $mostused[$key] = "$value/$code";
479 if ( count( $mostused ) ) {
480 $conds['page_title'] = $mostused;
481 } elseif ( $code !== $wgLanguageCode ) {
482 $conds[] = 'page_title' . $dbr->buildLike( $dbr->anyString(), '/', $code );
484 # Effectively disallows use of '/' character in NS_MEDIAWIKI for uses
485 # other than language code.
486 $conds[] = 'page_title NOT' .
487 $dbr->buildLike( $dbr->anyString(), '/', $dbr->anyString() );
490 # Conditions to fetch oversized pages to ignore them
492 $bigConds[] = 'page_len > ' . intval( $wgMaxMsgCacheEntrySize );
494 # Load titles for all oversized pages in the MediaWiki namespace
497 [ 'page_title', 'page_latest' ],
499 __METHOD__
. "($code)-big"
501 foreach ( $res as $row ) {
502 $cache[$row->page_title
] = '!TOO BIG';
503 // At least include revision ID so page changes are reflected in the hash
504 $cache['EXCESSIVE'][$row->page_title
] = $row->page_latest
;
507 # Conditions to load the remaining pages with their contents
508 $smallConds = $conds;
509 $smallConds[] = 'page_len <= ' . intval( $wgMaxMsgCacheEntrySize );
512 [ 'page', 'revision', 'text' ],
513 [ 'page_title', 'old_id', 'old_text', 'old_flags' ],
515 __METHOD__
. "($code)-small",
518 'revision' => [ 'JOIN', 'page_latest=rev_id' ],
519 'text' => [ 'JOIN', 'rev_text_id=old_id' ],
523 foreach ( $res as $row ) {
524 $text = Revision
::getRevisionText( $row );
525 if ( $text === false ) {
526 // Failed to fetch data; possible ES errors?
527 // Store a marker to fetch on-demand as a workaround...
528 // TODO Use a differnt marker
533 . ": failed to load message page text for {$row->page_title} ($code)"
536 $entry = ' ' . $text;
538 $cache[$row->page_title
] = $entry;
541 $cache['VERSION'] = MSG_CACHE_VERSION
;
544 # Hash for validating local cache (APC). No need to take into account
545 # messages larger than $wgMaxMsgCacheEntrySize, since those are only
546 # stored and fetched from memcache.
547 $cache['HASH'] = md5( serialize( $cache ) );
548 $cache['EXPIRY'] = wfTimestamp( TS_MW
, time() +
$this->mExpiry
);
554 * Updates cache as necessary when message page is changed
556 * @param string $title Message cache key with initial uppercase letter
557 * @param string|bool $text New contents of the page (false if deleted)
559 public function replace( $title, $text ) {
560 global $wgLanguageCode;
562 if ( $this->mDisable
) {
566 list( $msg, $code ) = $this->figureMessage( $title );
567 if ( strpos( $title, '/' ) !== false && $code === $wgLanguageCode ) {
568 // Content language overrides do not use the /<code> suffix
572 // (a) Update the process cache with the new message text
573 if ( $text === false ) {
575 $this->cache
->setField( $code, $title, '!NONEXISTENT' );
577 // Ignore $wgMaxMsgCacheEntrySize so the process cache is up to date
578 $this->cache
->setField( $code, $title, ' ' . $text );
581 // (b) Update the shared caches in a deferred update with a fresh DB snapshot
582 DeferredUpdates
::addCallableUpdate(
583 function () use ( $title, $msg, $code ) {
584 global $wgContLang, $wgMaxMsgCacheEntrySize;
585 // Allow one caller at a time to avoid race conditions
586 $scopedLock = $this->getReentrantScopedLock(
587 $this->clusterCache
->makeKey( 'messages', $code )
589 if ( !$scopedLock ) {
590 LoggerFactory
::getInstance( 'MessageCache' )->error(
591 __METHOD__
. ': could not acquire lock to update {title} ({code})',
592 [ 'title' => $title, 'code' => $code ] );
595 // Reload messages from the database and pre-populate dc-local caches
596 // as optimisation. Use the master DB to avoid race conditions.
597 $cache = $this->loadFromDB( $code, self
::FOR_UPDATE
);
598 // Check if an individual cache key should exist and update cache accordingly
599 $page = WikiPage
::factory( Title
::makeTitle( NS_MEDIAWIKI
, $title ) );
600 $page->loadPageData( $page::READ_LATEST
);
601 $text = $this->getMessageTextFromContent( $page->getContent() );
602 if ( is_string( $text ) && strlen( $text ) > $wgMaxMsgCacheEntrySize ) {
603 // Match logic of loadCachedMessagePageEntry()
604 $this->wanCache
->set(
605 $this->bigMessageCacheKey( $cache['HASH'], $title ),
610 // Mark this cache as definitely being "latest" (non-volatile) so
611 // load() calls do not try to refresh the cache with replica DB data
612 $cache['LATEST'] = time();
613 // Update the process cache
614 $this->cache
->set( $code, $cache );
615 // Pre-emptively update the local datacenter cache so things like edit filter and
616 // blacklist changes are reflected immediately; these often use MediaWiki: pages.
617 // The datacenter handling replace() calls should be the same one handling edits
618 // as they require HTTP POST.
619 $this->saveToCaches( $cache, 'all', $code );
620 // Release the lock now that the cache is saved
621 ScopedCallback
::consume( $scopedLock );
623 // Relay the purge. Touching this check key expires cache contents
624 // and local cache (APC) validation hash across all datacenters.
625 $this->wanCache
->touchCheckKey( $this->getCheckKey( $code ) );
627 // Purge the message in the message blob store
628 $resourceloader = RequestContext
::getMain()->getOutput()->getResourceLoader();
629 $blobStore = $resourceloader->getMessageBlobStore();
630 $blobStore->updateMessage( $wgContLang->lcfirst( $msg ) );
632 Hooks
::run( 'MessageCacheReplace', [ $title, $text ] );
634 DeferredUpdates
::PRESEND
639 * Is the given cache array expired due to time passing or a version change?
641 * @param array $cache
644 protected function isCacheExpired( $cache ) {
645 if ( !isset( $cache['VERSION'] ) ||
!isset( $cache['EXPIRY'] ) ) {
648 if ( $cache['VERSION'] != MSG_CACHE_VERSION
) {
651 if ( wfTimestampNow() >= $cache['EXPIRY'] ) {
659 * Shortcut to update caches.
661 * @param array $cache Cached messages with a version.
662 * @param string $dest Either "local-only" to save to local caches only
663 * or "all" to save to all caches.
664 * @param string|bool $code Language code (default: false)
667 protected function saveToCaches( array $cache, $dest, $code = false ) {
668 if ( $dest === 'all' ) {
669 $cacheKey = $this->clusterCache
->makeKey( 'messages', $code );
670 $success = $this->clusterCache
->set( $cacheKey, $cache );
671 $this->setValidationHash( $code, $cache );
676 $this->saveToLocalCache( $code, $cache );
682 * Get the md5 used to validate the local APC cache
684 * @param string $code
685 * @return array (hash or false, bool expiry/volatility status)
687 protected function getValidationHash( $code ) {
689 $value = $this->wanCache
->get(
690 $this->wanCache
->makeKey( 'messages', $code, 'hash', 'v1' ),
692 [ $this->getCheckKey( $code ) ]
696 $hash = $value['hash'];
697 if ( ( time() - $value['latest'] ) < WANObjectCache
::TTL_MINUTE
) {
698 // Cache was recently updated via replace() and should be up-to-date.
699 // That method is only called in the primary datacenter and uses FOR_UPDATE.
700 // Also, it is unlikely that the current datacenter is *now* secondary one.
703 // See if the "check" key was bumped after the hash was generated
704 $expired = ( $curTTL < 0 );
707 // No hash found at all; cache must regenerate to be safe
712 return [ $hash, $expired ];
716 * Set the md5 used to validate the local disk cache
718 * If $cache has a 'LATEST' UNIX timestamp key, then the hash will not
719 * be treated as "volatile" by getValidationHash() for the next few seconds.
720 * This is triggered when $cache is generated using FOR_UPDATE mode.
722 * @param string $code
723 * @param array $cache Cached messages with a version
725 protected function setValidationHash( $code, array $cache ) {
726 $this->wanCache
->set(
727 $this->wanCache
->makeKey( 'messages', $code, 'hash', 'v1' ),
729 'hash' => $cache['HASH'],
730 'latest' => $cache['LATEST'] ??
0
732 WANObjectCache
::TTL_INDEFINITE
737 * @param string $key A language message cache key that stores blobs
738 * @param int $timeout Wait timeout in seconds
739 * @return null|ScopedCallback
741 protected function getReentrantScopedLock( $key, $timeout = self
::WAIT_SEC
) {
742 return $this->clusterCache
->getScopedLock( $key, $timeout, self
::LOCK_TTL
, __METHOD__
);
746 * Get a message from either the content language or the user language.
748 * First, assemble a list of languages to attempt getting the message from. This
749 * chain begins with the requested language and its fallbacks and then continues with
750 * the content language and its fallbacks. For each language in the chain, the following
751 * process will occur (in this order):
752 * 1. If a language-specific override, i.e., [[MW:msg/lang]], is available, use that.
753 * Note: for the content language, there is no /lang subpage.
754 * 2. Fetch from the static CDB cache.
755 * 3. If available, check the database for fallback language overrides.
757 * This process provides a number of guarantees. When changing this code, make sure all
758 * of these guarantees are preserved.
759 * * If the requested language is *not* the content language, then the CDB cache for that
760 * specific language will take precedence over the root database page ([[MW:msg]]).
761 * * Fallbacks will be just that: fallbacks. A fallback language will never be reached if
762 * the message is available *anywhere* in the language for which it is a fallback.
764 * @param string $key The message key
765 * @param bool $useDB If true, look for the message in the DB, false
766 * to use only the compiled l10n cache.
767 * @param bool|string|object $langcode Code of the language to get the message for.
768 * - If string and a valid code, will create a standard language object
769 * - If string but not a valid code, will create a basic language object
770 * - If boolean and false, create object from the current users language
771 * - If boolean and true, create object from the wikis content language
772 * - If language object, use it as given
773 * @param bool $isFullKey Specifies whether $key is a two part key "msg/lang".
775 * @throws MWException When given an invalid key
776 * @return string|bool False if the message doesn't exist, otherwise the
777 * message (which can be empty)
779 function get( $key, $useDB = true, $langcode = true, $isFullKey = false ) {
780 if ( is_int( $key ) ) {
781 // Fix numerical strings that somehow become ints
784 } elseif ( !is_string( $key ) ) {
785 throw new MWException( 'Non-string key given' );
786 } elseif ( $key === '' ) {
787 // Shortcut: the empty key is always missing
791 // For full keys, get the language code from the key
792 $pos = strrpos( $key, '/' );
793 if ( $isFullKey && $pos !== false ) {
794 $langcode = substr( $key, $pos +
1 );
795 $key = substr( $key, 0, $pos );
798 // Normalise title-case input (with some inlining)
799 $lckey = self
::normalizeKey( $key );
801 Hooks
::run( 'MessageCache::get', [ &$lckey ] );
803 // Loop through each language in the fallback list until we find something useful
804 $lang = wfGetLangObj( $langcode );
805 $message = $this->getMessageFromFallbackChain(
808 !$this->mDisable
&& $useDB
811 // If we still have no message, maybe the key was in fact a full key so try that
812 if ( $message === false ) {
813 $parts = explode( '/', $lckey );
814 // We may get calls for things that are http-urls from sidebar
815 // Let's not load nonexistent languages for those
816 // They usually have more than one slash.
817 if ( count( $parts ) == 2 && $parts[1] !== '' ) {
818 $message = Language
::getMessageFor( $parts[0], $parts[1] );
819 if ( $message === null ) {
825 // Post-processing if the message exists
826 if ( $message !== false ) {
828 $message = str_replace(
830 # Fix for trailing whitespace, removed by textarea
832 # Fix for NBSP, converted to space by firefox
851 * Given a language, try and fetch messages from that language.
853 * Will also consider fallbacks of that language, the site language, and fallbacks for
856 * @see MessageCache::get
857 * @param Language|StubObject $lang Preferred language
858 * @param string $lckey Lowercase key for the message (as for localisation cache)
859 * @param bool $useDB Whether to include messages from the wiki database
860 * @return string|bool The message, or false if not found
862 protected function getMessageFromFallbackChain( $lang, $lckey, $useDB ) {
867 // First try the requested language.
868 $message = $this->getMessageForLang( $lang, $lckey, $useDB, $alreadyTried );
869 if ( $message !== false ) {
873 // Now try checking the site language.
874 $message = $this->getMessageForLang( $wgContLang, $lckey, $useDB, $alreadyTried );
879 * Given a language, try and fetch messages from that language and its fallbacks.
881 * @see MessageCache::get
882 * @param Language|StubObject $lang Preferred language
883 * @param string $lckey Lowercase key for the message (as for localisation cache)
884 * @param bool $useDB Whether to include messages from the wiki database
885 * @param bool[] $alreadyTried Contains true for each language that has been tried already
886 * @return string|bool The message, or false if not found
888 private function getMessageForLang( $lang, $lckey, $useDB, &$alreadyTried ) {
891 $langcode = $lang->getCode();
893 // Try checking the database for the requested language
895 $uckey = $wgContLang->ucfirst( $lckey );
897 if ( !isset( $alreadyTried[$langcode] ) ) {
898 $message = $this->getMsgFromNamespace(
899 $this->getMessagePageName( $langcode, $uckey ),
903 if ( $message !== false ) {
906 $alreadyTried[$langcode] = true;
912 // Check the CDB cache
913 $message = $lang->getMessage( $lckey );
914 if ( $message !== null ) {
918 // Try checking the database for all of the fallback languages
920 $fallbackChain = Language
::getFallbacksFor( $langcode );
922 foreach ( $fallbackChain as $code ) {
923 if ( isset( $alreadyTried[$code] ) ) {
927 $message = $this->getMsgFromNamespace(
928 $this->getMessagePageName( $code, $uckey ), $code );
930 if ( $message !== false ) {
933 $alreadyTried[$code] = true;
941 * Get the message page name for a given language
943 * @param string $langcode
944 * @param string $uckey Uppercase key for the message
945 * @return string The page name
947 private function getMessagePageName( $langcode, $uckey ) {
948 global $wgLanguageCode;
950 if ( $langcode === $wgLanguageCode ) {
951 // Messages created in the content language will not have the /lang extension
954 return "$uckey/$langcode";
959 * Get a message from the MediaWiki namespace, with caching. The key must
960 * first be converted to two-part lang/msg form if necessary.
962 * Unlike self::get(), this function doesn't resolve fallback chains, and
963 * some callers require this behavior. LanguageConverter::parseCachedTable()
964 * and self::get() are some examples in core.
966 * @param string $title Message cache key with initial uppercase letter
967 * @param string $code Code denoting the language to try
968 * @return string|bool The message, or false if it does not exist or on error
970 public function getMsgFromNamespace( $title, $code ) {
971 // Load all MediaWiki page definitions into cache. Note that individual keys
972 // already loaded into cache during this request remain in the cache, which
973 // includes the value of hook-defined messages.
974 $this->load( $code );
976 $entry = $this->cache
->getField( $code, $title );
977 if ( $entry !== null ) {
978 if ( substr( $entry, 0, 1 ) === ' ' ) {
979 // The message exists and is not '!TOO BIG'
980 return (string)substr( $entry, 1 );
981 } elseif ( $entry === '!NONEXISTENT' ) {
984 // Fall through and try invididual message cache below
986 // Message does not have a MediaWiki page definition
988 Hooks
::run( 'MessagesPreLoad', [ $title, &$message, $code ] );
989 if ( $message !== false ) {
990 $this->cache
->setField( $code, $title, ' ' . $message );
992 $this->cache
->setField( $code, $title, '!NONEXISTENT' );
998 if ( $this->cacheVolatile
[$code] ) {
1000 // Make sure that individual keys respect the WAN cache holdoff period too
1001 LoggerFactory
::getInstance( 'MessageCache' )->debug(
1002 __METHOD__
. ': loading volatile key \'{titleKey}\'',
1003 [ 'titleKey' => $title, 'code' => $code ] );
1005 // Try the individual message cache
1006 $entry = $this->loadCachedMessagePageEntry(
1009 $this->cache
->getField( $code, 'HASH' )
1013 if ( $entry !== false && substr( $entry, 0, 1 ) === ' ' ) {
1014 $this->cache
->setField( $code, $title, $entry );
1015 // The message exists, so make sure a string is returned
1016 return (string)substr( $entry, 1 );
1019 $this->cache
->setField( $code, $title, '!NONEXISTENT' );
1025 * @param string $dbKey
1026 * @param string $code
1027 * @param string $hash
1028 * @return string Either " <MESSAGE>" or "!NONEXISTANT"
1030 private function loadCachedMessagePageEntry( $dbKey, $code, $hash ) {
1031 return $this->wanCache
->getWithSetCallback(
1032 $this->bigMessageCacheKey( $hash, $dbKey ),
1034 function ( $oldValue, &$ttl, &$setOpts ) use ( $dbKey, $code ) {
1035 // Try loading the message from the database
1036 $dbr = wfGetDB( DB_REPLICA
);
1037 $setOpts +
= Database
::getCacheSetOptions( $dbr );
1038 // Use newKnownCurrent() to avoid querying revision/user tables
1039 $title = Title
::makeTitle( NS_MEDIAWIKI
, $dbKey );
1040 $revision = Revision
::newKnownCurrent( $dbr, $title );
1042 // The wiki doesn't have a local override page. Cache absence with normal TTL.
1043 // When overrides are created, self::replace() takes care of the cache.
1044 return '!NONEXISTENT';
1046 $content = $revision->getContent();
1048 $message = $this->getMessageTextFromContent( $content );
1050 LoggerFactory
::getInstance( 'MessageCache' )->warning(
1051 __METHOD__
. ': failed to load page text for \'{titleKey}\'',
1052 [ 'titleKey' => $dbKey, 'code' => $code ]
1057 if ( !is_string( $message ) ) {
1058 // Revision failed to load Content, or Content is incompatible with wikitext.
1059 // Possibly a temporary loading failure.
1061 return '!NONEXISTENT';
1064 return ' ' . $message;
1070 * @param string $message
1071 * @param bool $interface
1072 * @param Language|null $language
1073 * @param Title|null $title
1076 public function transform( $message, $interface = false, $language = null, $title = null ) {
1077 // Avoid creating parser if nothing to transform
1078 if ( strpos( $message, '{{' ) === false ) {
1082 if ( $this->mInParser
) {
1086 $parser = $this->getParser();
1088 $popts = $this->getParserOptions();
1089 $popts->setInterfaceMessage( $interface );
1090 $popts->setTargetLanguage( $language );
1092 $userlang = $popts->setUserLang( $language );
1093 $this->mInParser
= true;
1094 $message = $parser->transformMsg( $message, $popts, $title );
1095 $this->mInParser
= false;
1096 $popts->setUserLang( $userlang );
1105 public function getParser() {
1106 global $wgParser, $wgParserConf;
1108 if ( !$this->mParser
&& isset( $wgParser ) ) {
1109 # Do some initialisation so that we don't have to do it twice
1110 $wgParser->firstCallInit();
1111 # Clone it and store it
1112 $class = $wgParserConf['class'];
1113 if ( $class == ParserDiffTest
::class ) {
1115 $this->mParser
= new $class( $wgParserConf );
1117 $this->mParser
= clone $wgParser;
1121 return $this->mParser
;
1125 * @param string $text
1126 * @param Title|null $title
1127 * @param bool $linestart Whether or not this is at the start of a line
1128 * @param bool $interface Whether this is an interface message
1129 * @param Language|string|null $language Language code
1130 * @return ParserOutput|string
1132 public function parse( $text, $title = null, $linestart = true,
1133 $interface = false, $language = null
1137 if ( $this->mInParser
) {
1138 return htmlspecialchars( $text );
1141 $parser = $this->getParser();
1142 $popts = $this->getParserOptions();
1143 $popts->setInterfaceMessage( $interface );
1145 if ( is_string( $language ) ) {
1146 $language = Language
::factory( $language );
1148 $popts->setTargetLanguage( $language );
1150 if ( !$title ||
!$title instanceof Title
) {
1151 wfDebugLog( 'GlobalTitleFail', __METHOD__
. ' called by ' .
1152 wfGetAllCallers( 6 ) . ' with no title set.' );
1155 // Sometimes $wgTitle isn't set either...
1157 # It's not uncommon having a null $wgTitle in scripts. See r80898
1158 # Create a ghost title in such case
1159 $title = Title
::makeTitle( NS_SPECIAL
, 'Badtitle/title not set in ' . __METHOD__
);
1162 $this->mInParser
= true;
1163 $res = $parser->parse( $text, $title, $popts, $linestart );
1164 $this->mInParser
= false;
1169 public function disable() {
1170 $this->mDisable
= true;
1173 public function enable() {
1174 $this->mDisable
= false;
1178 * Whether DB/cache usage is disabled for determining messages
1180 * If so, this typically indicates either:
1181 * - a) load() failed to find a cached copy nor query the DB
1182 * - b) we are in a special context or error mode that cannot use the DB
1183 * If the DB is ignored, any derived HTML output or cached objects may be wrong.
1184 * To avoid long-term cache pollution, TTLs can be adjusted accordingly.
1189 public function isDisabled() {
1190 return $this->mDisable
;
1194 * Clear all stored messages in global and local cache
1196 * Mainly used after a mass rebuild
1198 public function clear() {
1199 $langs = Language
::fetchLanguageNames( null, 'mw' );
1200 foreach ( array_keys( $langs ) as $code ) {
1201 $this->wanCache
->touchCheckKey( $this->getCheckKey( $code ) );
1203 $this->cache
->clear();
1207 * @param string $key
1210 public function figureMessage( $key ) {
1211 global $wgLanguageCode;
1213 $pieces = explode( '/', $key );
1214 if ( count( $pieces ) < 2 ) {
1215 return [ $key, $wgLanguageCode ];
1218 $lang = array_pop( $pieces );
1219 if ( !Language
::fetchLanguageName( $lang, null, 'mw' ) ) {
1220 return [ $key, $wgLanguageCode ];
1223 $message = implode( '/', $pieces );
1225 return [ $message, $lang ];
1229 * Get all message keys stored in the message cache for a given language.
1230 * If $code is the content language code, this will return all message keys
1231 * for which MediaWiki:msgkey exists. If $code is another language code, this
1232 * will ONLY return message keys for which MediaWiki:msgkey/$code exists.
1233 * @param string $code Language code
1234 * @return array Array of message keys (strings)
1236 public function getAllMessageKeys( $code ) {
1239 $this->load( $code );
1240 if ( !$this->cache
->has( $code ) ) {
1241 // Apparently load() failed
1244 // Remove administrative keys
1245 $cache = $this->cache
->get( $code );
1246 unset( $cache['VERSION'] );
1247 unset( $cache['EXPIRY'] );
1248 unset( $cache['EXCESSIVE'] );
1249 // Remove any !NONEXISTENT keys
1250 $cache = array_diff( $cache, [ '!NONEXISTENT' ] );
1252 // Keys may appear with a capital first letter. lcfirst them.
1253 return array_map( [ $wgContLang, 'lcfirst' ], array_keys( $cache ) );
1257 * Purge message caches when a MediaWiki: page is created, updated, or deleted
1259 * @param Title $title Message page title
1260 * @param Content|null $content New content for edit/create, null on deletion
1263 public function updateMessageOverride( Title
$title, Content
$content = null ) {
1266 $msgText = $this->getMessageTextFromContent( $content );
1267 if ( $msgText === null ) {
1268 $msgText = false; // treat as not existing
1271 $this->replace( $title->getDBkey(), $msgText );
1273 if ( $wgContLang->hasVariants() ) {
1274 $wgContLang->updateConversionTable( $title );
1279 * @param string $code Language code
1280 * @return string WAN cache key usable as a "check key" against language page edits
1282 public function getCheckKey( $code ) {
1283 return $this->wanCache
->makeKey( 'messages', $code );
1287 * @param Content|null $content Content or null if the message page does not exist
1288 * @return string|bool|null Returns false if $content is null and null on error
1290 private function getMessageTextFromContent( Content
$content = null ) {
1291 // @TODO: could skip pseudo-messages like js/css here, based on content model
1293 // Message page exists...
1294 // XXX: Is this the right way to turn a Content object into a message?
1295 // NOTE: $content is typically either WikitextContent, JavaScriptContent or
1296 // CssContent. MessageContent is *not* used for storing messages, it's
1297 // only used for wrapping them when needed.
1298 $msgText = $content->getWikitextForTransclusion();
1299 if ( $msgText === false ||
$msgText === null ) {
1300 // This might be due to some kind of misconfiguration...
1302 LoggerFactory
::getInstance( 'MessageCache' )->warning(
1303 __METHOD__
. ": message content doesn't provide wikitext "
1304 . "(content model: " . $content->getModel() . ")" );
1307 // Message page does not exist...
1315 * @param string $hash Hash for this version of the entire key/value overrides map
1316 * @param string $title Message cache key with initial uppercase letter
1319 private function bigMessageCacheKey( $hash, $title ) {
1320 return $this->wanCache
->makeKey( 'messages-big', $hash, $title );