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
;
27 * MediaWiki message cache structure version.
28 * Bump this whenever the message cache format has changed.
30 define( 'MSG_CACHE_VERSION', 2 );
34 * Performs various MediaWiki namespace-related functions
38 const FOR_UPDATE
= 1; // force message reload
40 /** How long to wait for memcached locks */
42 /** How long memcached locks last */
46 * Process local cache of loaded messages that are defined in
47 * MediaWiki namespace. First array level is a language code,
48 * second level is message key and the values are either message
49 * content prefixed with space, or !NONEXISTENT for negative
56 * Should mean that database cannot be used, but check
62 * Lifetime for cache, used by object caching.
63 * Set on construction, see __construct().
68 * Message cache has its own parser which it uses to transform
71 protected $mParserOptions, $mParser;
74 * Variable for tracking which variables are already loaded
75 * @var array $mLoadedLanguages
77 protected $mLoadedLanguages = [];
80 * @var bool $mInParser
82 protected $mInParser = false;
86 /** @var WANObjectCache */
92 * @var MessageCache $instance
94 private static $instance;
97 * Get the signleton instance of this class
100 * @return MessageCache
102 public static function singleton() {
103 if ( self
::$instance === null ) {
104 global $wgUseDatabaseMessages, $wgMsgCacheExpiry;
105 self
::$instance = new self(
106 wfGetMessageCacheStorage(),
107 $wgUseDatabaseMessages,
112 return self
::$instance;
116 * Destroy the singleton instance
120 public static function destroyInstance() {
121 self
::$instance = null;
125 * Normalize message key input
127 * @param string $key Input message key to be normalized
128 * @return string Normalized message key
130 public static function normalizeKey( $key ) {
132 $lckey = strtr( $key, ' ', '_' );
133 if ( ord( $lckey ) < 128 ) {
134 $lckey[0] = strtolower( $lckey[0] );
136 $lckey = $wgContLang->lcfirst( $lckey );
143 * @param BagOStuff $memCached A cache instance. If none, fall back to CACHE_NONE.
145 * @param int $expiry Lifetime for cache. @see $mExpiry.
147 function __construct( $memCached, $useDB, $expiry ) {
148 global $wgUseLocalMessageCache;
151 $memCached = wfGetCache( CACHE_NONE
);
154 $this->mMemc
= $memCached;
155 $this->mDisable
= !$useDB;
156 $this->mExpiry
= $expiry;
158 if ( $wgUseLocalMessageCache ) {
159 $this->localCache
= MediaWikiServices
::getInstance()->getLocalServerObjectCache();
161 $this->localCache
= new EmptyBagOStuff();
164 $this->wanCache
= ObjectCache
::getMainWANInstance();
168 * ParserOptions is lazy initialised.
170 * @return ParserOptions
172 function getParserOptions() {
175 if ( !$this->mParserOptions
) {
176 if ( !$wgUser->isSafeToLoad() ) {
177 // $wgUser isn't unstubbable yet, so don't try to get a
178 // ParserOptions for it. And don't cache this ParserOptions
180 $po = ParserOptions
::newFromAnon();
181 $po->setEditSection( false );
185 $this->mParserOptions
= new ParserOptions
;
186 $this->mParserOptions
->setEditSection( false );
189 return $this->mParserOptions
;
193 * Try to load the cache from APC.
195 * @param string $code Optional language code, see documenation of load().
196 * @return array|bool The cache array, or false if not in cache.
198 protected function getLocalCache( $code ) {
199 $cacheKey = wfMemcKey( __CLASS__
, $code );
201 return $this->localCache
->get( $cacheKey );
205 * Save the cache to APC.
207 * @param string $code
208 * @param array $cache The cache array
210 protected function saveToLocalCache( $code, $cache ) {
211 $cacheKey = wfMemcKey( __CLASS__
, $code );
212 $this->localCache
->set( $cacheKey, $cache );
216 * Loads messages from caches or from database in this order:
217 * (1) local message cache (if $wgUseLocalMessageCache is enabled)
219 * (3) from the database.
221 * When succesfully loading from (2) or (3), all higher level caches are
222 * updated for the newest version.
224 * Nothing is loaded if member variable mDisable is true, either manually
225 * set by calling code or if message loading fails (is this possible?).
227 * Returns true if cache is already populated or it was succesfully populated,
228 * or false if populating empty cache fails. Also returns true if MessageCache
231 * @param string $code Language to which load messages
232 * @param integer $mode Use MessageCache::FOR_UPDATE to skip process cache [optional]
233 * @throws MWException
236 protected function load( $code, $mode = null ) {
237 if ( !is_string( $code ) ) {
238 throw new InvalidArgumentException( "Missing language code" );
241 # Don't do double loading...
242 if ( isset( $this->mLoadedLanguages
[$code] ) && $mode != self
::FOR_UPDATE
) {
246 # 8 lines of code just to say (once) that message cache is disabled
247 if ( $this->mDisable
) {
248 static $shownDisabled = false;
249 if ( !$shownDisabled ) {
250 wfDebug( __METHOD__
. ": disabled\n" );
251 $shownDisabled = true;
257 # Loading code starts
258 $success = false; # Keep track of success
259 $staleCache = false; # a cache array with expired data, or false if none has been loaded
260 $where = []; # Debug info, delayed to avoid spamming debug log too much
262 # Hash of the contents is stored in memcache, to detect if data-center cache
263 # or local cache goes out of date (e.g. due to replace() on some other server)
264 list( $hash, $hashVolatile ) = $this->getValidationHash( $code );
266 # Try the local cache and check against the cluster hash key...
267 $cache = $this->getLocalCache( $code );
269 $where[] = 'local cache is empty';
270 } elseif ( !isset( $cache['HASH'] ) ||
$cache['HASH'] !== $hash ) {
271 $where[] = 'local cache has the wrong hash';
272 $staleCache = $cache;
273 } elseif ( $this->isCacheExpired( $cache ) ) {
274 $where[] = 'local cache is expired';
275 $staleCache = $cache;
276 } elseif ( $hashVolatile ) {
277 $where[] = 'local cache validation key is expired/volatile';
278 $staleCache = $cache;
280 $where[] = 'got from local cache';
282 $this->mCache
[$code] = $cache;
286 $cacheKey = wfMemcKey( 'messages', $code ); # Key in memc for messages
287 # Try the global cache. If it is empty, try to acquire a lock. If
288 # the lock can't be acquired, wait for the other thread to finish
289 # and then try the global cache a second time.
290 for ( $failedAttempts = 0; $failedAttempts <= 1; $failedAttempts++
) {
291 if ( $hashVolatile && $staleCache ) {
292 # Do not bother fetching the whole cache blob to avoid I/O.
293 # Instead, just try to get the non-blocking $statusKey lock
294 # below, and use the local stale value if it was not acquired.
295 $where[] = 'global cache is presumed expired';
297 $cache = $this->mMemc
->get( $cacheKey );
299 $where[] = 'global cache is empty';
300 } elseif ( $this->isCacheExpired( $cache ) ) {
301 $where[] = 'global cache is expired';
302 $staleCache = $cache;
303 } elseif ( $hashVolatile ) {
304 # DB results are replica DB lag prone until the holdoff TTL passes.
305 # By then, updates should be reflected in loadFromDBWithLock().
306 # One thread renerates the cache while others use old values.
307 $where[] = 'global cache is expired/volatile';
308 $staleCache = $cache;
310 $where[] = 'got from global cache';
311 $this->mCache
[$code] = $cache;
312 $this->saveToCaches( $cache, 'local-only', $code );
318 # Done, no need to retry
322 # We need to call loadFromDB. Limit the concurrency to one process.
323 # This prevents the site from going down when the cache expires.
324 # Note that the DB slam protection lock here is non-blocking.
325 $loadStatus = $this->loadFromDBWithLock( $code, $where, $mode );
326 if ( $loadStatus === true ) {
329 } elseif ( $staleCache ) {
330 # Use the stale cache while some other thread constructs the new one
331 $where[] = 'using stale cache';
332 $this->mCache
[$code] = $staleCache;
335 } elseif ( $failedAttempts > 0 ) {
336 # Already blocked once, so avoid another lock/unlock cycle.
337 # This case will typically be hit if memcached is down, or if
338 # loadFromDB() takes longer than LOCK_WAIT.
339 $where[] = "could not acquire status key.";
341 } elseif ( $loadStatus === 'cantacquire' ) {
342 # Wait for the other thread to finish, then retry. Normally,
343 # the memcached get() will then yeild the other thread's result.
344 $where[] = 'waited for other thread to complete';
345 $this->getReentrantScopedLock( $cacheKey );
347 # Disable cache; $loadStatus is 'disabled'
354 $where[] = 'loading FAILED - cache is disabled';
355 $this->mDisable
= true;
356 $this->mCache
= false;
357 wfDebugLog( 'MessageCacheError', __METHOD__
. ": Failed to load $code\n" );
358 # This used to throw an exception, but that led to nasty side effects like
359 # the whole wiki being instantly down if the memcached server died
361 # All good, just record the success
362 $this->mLoadedLanguages
[$code] = true;
365 $info = implode( ', ', $where );
366 wfDebugLog( 'MessageCache', __METHOD__
. ": Loading $code... $info\n" );
372 * @param string $code
373 * @param array $where List of wfDebug() comments
374 * @param integer $mode Use MessageCache::FOR_UPDATE to use DB_MASTER
375 * @return bool|string True on success or one of ("cantacquire", "disabled")
377 protected function loadFromDBWithLock( $code, array &$where, $mode = null ) {
378 global $wgUseLocalMessageCache;
380 # If cache updates on all levels fail, give up on message overrides.
381 # This is to avoid easy site outages; see $saveSuccess comments below.
382 $statusKey = wfMemcKey( 'messages', $code, 'status' );
383 $status = $this->mMemc
->get( $statusKey );
384 if ( $status === 'error' ) {
385 $where[] = "could not load; method is still globally disabled";
389 # Now let's regenerate
390 $where[] = 'loading from database';
392 # Lock the cache to prevent conflicting writes.
393 # This lock is non-blocking so stale cache can quickly be used.
394 # Note that load() will call a blocking getReentrantScopedLock()
395 # after this if it really need to wait for any current thread.
396 $cacheKey = wfMemcKey( 'messages', $code );
397 $scopedLock = $this->getReentrantScopedLock( $cacheKey, 0 );
398 if ( !$scopedLock ) {
399 $where[] = 'could not acquire main lock';
400 return 'cantacquire';
403 $cache = $this->loadFromDB( $code, $mode );
404 $this->mCache
[$code] = $cache;
405 $saveSuccess = $this->saveToCaches( $cache, 'all', $code );
407 if ( !$saveSuccess ) {
409 * Cache save has failed.
411 * There are two main scenarios where this could be a problem:
412 * - The cache is more than the maximum size (typically 1MB compressed).
413 * - Memcached has no space remaining in the relevant slab class. This is
414 * unlikely with recent versions of memcached.
416 * Either way, if there is a local cache, nothing bad will happen. If there
417 * is no local cache, disabling the message cache for all requests avoids
418 * incurring a loadFromDB() overhead on every request, and thus saves the
419 * wiki from complete downtime under moderate traffic conditions.
421 if ( !$wgUseLocalMessageCache ) {
422 $this->mMemc
->set( $statusKey, 'error', 60 * 5 );
423 $where[] = 'could not save cache, disabled globally for 5 minutes';
425 $where[] = "could not save global cache";
433 * Loads cacheable messages from the database. Messages bigger than
434 * $wgMaxMsgCacheEntrySize are assigned a special value, and are loaded
435 * on-demand from the database later.
437 * @param string $code Language code
438 * @param integer $mode Use MessageCache::FOR_UPDATE to skip process cache
439 * @return array Loaded messages for storing in caches
441 function loadFromDB( $code, $mode = null ) {
442 global $wgMaxMsgCacheEntrySize, $wgLanguageCode, $wgAdaptiveMessageCache;
444 $dbr = wfGetDB( ( $mode == self
::FOR_UPDATE
) ? DB_MASTER
: DB_REPLICA
);
450 'page_is_redirect' => 0,
451 'page_namespace' => NS_MEDIAWIKI
,
455 if ( $wgAdaptiveMessageCache && $code !== $wgLanguageCode ) {
456 if ( !isset( $this->mCache
[$wgLanguageCode] ) ) {
457 $this->load( $wgLanguageCode );
459 $mostused = array_keys( $this->mCache
[$wgLanguageCode] );
460 foreach ( $mostused as $key => $value ) {
461 $mostused[$key] = "$value/$code";
465 if ( count( $mostused ) ) {
466 $conds['page_title'] = $mostused;
467 } elseif ( $code !== $wgLanguageCode ) {
468 $conds[] = 'page_title' . $dbr->buildLike( $dbr->anyString(), '/', $code );
470 # Effectively disallows use of '/' character in NS_MEDIAWIKI for uses
471 # other than language code.
472 $conds[] = 'page_title NOT' . $dbr->buildLike( $dbr->anyString(), '/', $dbr->anyString() );
475 # Conditions to fetch oversized pages to ignore them
477 $bigConds[] = 'page_len > ' . intval( $wgMaxMsgCacheEntrySize );
479 # Load titles for all oversized pages in the MediaWiki namespace
480 $res = $dbr->select( 'page', 'page_title', $bigConds, __METHOD__
. "($code)-big" );
481 foreach ( $res as $row ) {
482 $cache[$row->page_title
] = '!TOO BIG';
485 # Conditions to load the remaining pages with their contents
486 $smallConds = $conds;
487 $smallConds[] = 'page_latest=rev_id';
488 $smallConds[] = 'rev_text_id=old_id';
489 $smallConds[] = 'page_len <= ' . intval( $wgMaxMsgCacheEntrySize );
492 [ 'page', 'revision', 'text' ],
493 [ 'page_title', 'old_text', 'old_flags' ],
495 __METHOD__
. "($code)-small"
498 foreach ( $res as $row ) {
499 $text = Revision
::getRevisionText( $row );
500 if ( $text === false ) {
501 // Failed to fetch data; possible ES errors?
502 // Store a marker to fetch on-demand as a workaround...
507 . ": failed to load message page text for {$row->page_title} ($code)"
510 $entry = ' ' . $text;
512 $cache[$row->page_title
] = $entry;
515 $cache['VERSION'] = MSG_CACHE_VERSION
;
517 $cache['HASH'] = md5( serialize( $cache ) );
518 $cache['EXPIRY'] = wfTimestamp( TS_MW
, time() +
$this->mExpiry
);
524 * Updates cache as necessary when message page is changed
526 * @param string|bool $title Name of the page changed (false if deleted)
527 * @param mixed $text New contents of the page.
529 public function replace( $title, $text ) {
530 global $wgMaxMsgCacheEntrySize, $wgContLang, $wgLanguageCode;
532 if ( $this->mDisable
) {
536 list( $msg, $code ) = $this->figureMessage( $title );
537 if ( strpos( $title, '/' ) !== false && $code === $wgLanguageCode ) {
538 // Content language overrides do not use the /<code> suffix
542 // Note that if the cache is volatile, load() may trigger a DB fetch.
543 // In that case we reenter/reuse the existing cache key lock to avoid
544 // a self-deadlock. This is safe as no reads happen *directly* in this
545 // method between getReentrantScopedLock() and load() below. There is
546 // no risk of data "changing under our feet" for replace().
547 $cacheKey = wfMemcKey( 'messages', $code );
548 $scopedLock = $this->getReentrantScopedLock( $cacheKey );
549 $this->load( $code, self
::FOR_UPDATE
);
551 $titleKey = wfMemcKey( 'messages', 'individual', $title );
552 if ( $text === false ) {
553 // Article was deleted
554 $this->mCache
[$code][$title] = '!NONEXISTENT';
555 $this->wanCache
->delete( $titleKey );
556 } elseif ( strlen( $text ) > $wgMaxMsgCacheEntrySize ) {
558 $this->mCache
[$code][$title] = '!TOO BIG';
559 $this->wanCache
->set( $titleKey, ' ' . $text, $this->mExpiry
);
561 $this->mCache
[$code][$title] = ' ' . $text;
562 $this->wanCache
->delete( $titleKey );
565 // Mark this cache as definitely "latest" (non-volatile) so
566 // load() calls do try to refresh the cache with replica DB data
567 $this->mCache
[$code]['LATEST'] = time();
569 // Update caches if the lock was acquired
571 $this->saveToCaches( $this->mCache
[$code], 'all', $code );
574 ScopedCallback
::consume( $scopedLock );
575 // Relay the purge to APC and other DCs
576 $this->wanCache
->touchCheckKey( wfMemcKey( 'messages', $code ) );
578 // Also delete cached sidebar... just in case it is affected
580 if ( $code === 'en' ) {
581 // Delete all sidebars, like for example on action=purge on the
583 $codes = array_keys( Language
::fetchLanguageNames() );
586 foreach ( $codes as $code ) {
587 $sidebarKey = wfMemcKey( 'sidebar', $code );
588 $this->wanCache
->delete( $sidebarKey );
591 // Update the message in the message blob store
592 $resourceloader = RequestContext
::getMain()->getOutput()->getResourceLoader();
593 $blobStore = $resourceloader->getMessageBlobStore();
594 $blobStore->updateMessage( $wgContLang->lcfirst( $msg ) );
596 Hooks
::run( 'MessageCacheReplace', [ $title, $text ] );
600 * Is the given cache array expired due to time passing or a version change?
602 * @param array $cache
605 protected function isCacheExpired( $cache ) {
606 if ( !isset( $cache['VERSION'] ) ||
!isset( $cache['EXPIRY'] ) ) {
609 if ( $cache['VERSION'] != MSG_CACHE_VERSION
) {
612 if ( wfTimestampNow() >= $cache['EXPIRY'] ) {
620 * Shortcut to update caches.
622 * @param array $cache Cached messages with a version.
623 * @param string $dest Either "local-only" to save to local caches only
624 * or "all" to save to all caches.
625 * @param string|bool $code Language code (default: false)
628 protected function saveToCaches( array $cache, $dest, $code = false ) {
629 if ( $dest === 'all' ) {
630 $cacheKey = wfMemcKey( 'messages', $code );
631 $success = $this->mMemc
->set( $cacheKey, $cache );
632 $this->setValidationHash( $code, $cache );
637 $this->saveToLocalCache( $code, $cache );
643 * Get the md5 used to validate the local APC cache
645 * @param string $code
646 * @return array (hash or false, bool expiry/volatility status)
648 protected function getValidationHash( $code ) {
650 $value = $this->wanCache
->get(
651 wfMemcKey( 'messages', $code, 'hash', 'v1' ),
653 [ wfMemcKey( 'messages', $code ) ]
657 // No hash found at all; cache must regenerate to be safe
661 $hash = $value['hash'];
662 if ( ( time() - $value['latest'] ) < WANObjectCache
::HOLDOFF_TTL
) {
663 // Cache was recently updated via replace() and should be up-to-date
666 // See if the "check" key was bumped after the hash was generated
667 $expired = ( $curTTL < 0 );
671 return [ $hash, $expired ];
675 * Set the md5 used to validate the local disk cache
677 * If $cache has a 'LATEST' UNIX timestamp key, then the hash will not
678 * be treated as "volatile" by getValidationHash() for the next few seconds
680 * @param string $code
681 * @param array $cache Cached messages with a version
683 protected function setValidationHash( $code, array $cache ) {
684 $this->wanCache
->set(
685 wfMemcKey( 'messages', $code, 'hash', 'v1' ),
687 'hash' => $cache['HASH'],
688 'latest' => isset( $cache['LATEST'] ) ?
$cache['LATEST'] : 0
690 WANObjectCache
::TTL_INDEFINITE
695 * @param string $key A language message cache key that stores blobs
696 * @param integer $timeout Wait timeout in seconds
697 * @return null|ScopedCallback
699 protected function getReentrantScopedLock( $key, $timeout = self
::WAIT_SEC
) {
700 return $this->mMemc
->getScopedLock( $key, $timeout, self
::LOCK_TTL
, __METHOD__
);
704 * Get a message from either the content language or the user language.
706 * First, assemble a list of languages to attempt getting the message from. This
707 * chain begins with the requested language and its fallbacks and then continues with
708 * the content language and its fallbacks. For each language in the chain, the following
709 * process will occur (in this order):
710 * 1. If a language-specific override, i.e., [[MW:msg/lang]], is available, use that.
711 * Note: for the content language, there is no /lang subpage.
712 * 2. Fetch from the static CDB cache.
713 * 3. If available, check the database for fallback language overrides.
715 * This process provides a number of guarantees. When changing this code, make sure all
716 * of these guarantees are preserved.
717 * * If the requested language is *not* the content language, then the CDB cache for that
718 * specific language will take precedence over the root database page ([[MW:msg]]).
719 * * Fallbacks will be just that: fallbacks. A fallback language will never be reached if
720 * the message is available *anywhere* in the language for which it is a fallback.
722 * @param string $key The message key
723 * @param bool $useDB If true, look for the message in the DB, false
724 * to use only the compiled l10n cache.
725 * @param bool|string|object $langcode Code of the language to get the message for.
726 * - If string and a valid code, will create a standard language object
727 * - If string but not a valid code, will create a basic language object
728 * - If boolean and false, create object from the current users language
729 * - If boolean and true, create object from the wikis content language
730 * - If language object, use it as given
731 * @param bool $isFullKey Specifies whether $key is a two part key "msg/lang".
733 * @throws MWException When given an invalid key
734 * @return string|bool False if the message doesn't exist, otherwise the
735 * message (which can be empty)
737 function get( $key, $useDB = true, $langcode = true, $isFullKey = false ) {
738 if ( is_int( $key ) ) {
739 // Fix numerical strings that somehow become ints
742 } elseif ( !is_string( $key ) ) {
743 throw new MWException( 'Non-string key given' );
744 } elseif ( $key === '' ) {
745 // Shortcut: the empty key is always missing
749 // For full keys, get the language code from the key
750 $pos = strrpos( $key, '/' );
751 if ( $isFullKey && $pos !== false ) {
752 $langcode = substr( $key, $pos +
1 );
753 $key = substr( $key, 0, $pos );
756 // Normalise title-case input (with some inlining)
757 $lckey = MessageCache
::normalizeKey( $key );
759 Hooks
::run( 'MessageCache::get', [ &$lckey ] );
761 // Loop through each language in the fallback list until we find something useful
762 $lang = wfGetLangObj( $langcode );
763 $message = $this->getMessageFromFallbackChain(
766 !$this->mDisable
&& $useDB
769 // If we still have no message, maybe the key was in fact a full key so try that
770 if ( $message === false ) {
771 $parts = explode( '/', $lckey );
772 // We may get calls for things that are http-urls from sidebar
773 // Let's not load nonexistent languages for those
774 // They usually have more than one slash.
775 if ( count( $parts ) == 2 && $parts[1] !== '' ) {
776 $message = Language
::getMessageFor( $parts[0], $parts[1] );
777 if ( $message === null ) {
783 // Post-processing if the message exists
784 if ( $message !== false ) {
786 $message = str_replace(
788 # Fix for trailing whitespace, removed by textarea
790 # Fix for NBSP, converted to space by firefox
809 * Given a language, try and fetch messages from that language.
811 * Will also consider fallbacks of that language, the site language, and fallbacks for
814 * @see MessageCache::get
815 * @param Language|StubObject $lang Preferred language
816 * @param string $lckey Lowercase key for the message (as for localisation cache)
817 * @param bool $useDB Whether to include messages from the wiki database
818 * @return string|bool The message, or false if not found
820 protected function getMessageFromFallbackChain( $lang, $lckey, $useDB ) {
825 // First try the requested language.
826 $message = $this->getMessageForLang( $lang, $lckey, $useDB, $alreadyTried );
827 if ( $message !== false ) {
831 // Now try checking the site language.
832 $message = $this->getMessageForLang( $wgContLang, $lckey, $useDB, $alreadyTried );
837 * Given a language, try and fetch messages from that language and its fallbacks.
839 * @see MessageCache::get
840 * @param Language|StubObject $lang Preferred language
841 * @param string $lckey Lowercase key for the message (as for localisation cache)
842 * @param bool $useDB Whether to include messages from the wiki database
843 * @param bool[] $alreadyTried Contains true for each language that has been tried already
844 * @return string|bool The message, or false if not found
846 private function getMessageForLang( $lang, $lckey, $useDB, &$alreadyTried ) {
848 $langcode = $lang->getCode();
850 // Try checking the database for the requested language
852 $uckey = $wgContLang->ucfirst( $lckey );
854 if ( !isset( $alreadyTried[ $langcode ] ) ) {
855 $message = $this->getMsgFromNamespace(
856 $this->getMessagePageName( $langcode, $uckey ),
860 if ( $message !== false ) {
863 $alreadyTried[ $langcode ] = true;
869 // Check the CDB cache
870 $message = $lang->getMessage( $lckey );
871 if ( $message !== null ) {
875 // Try checking the database for all of the fallback languages
877 $fallbackChain = Language
::getFallbacksFor( $langcode );
879 foreach ( $fallbackChain as $code ) {
880 if ( isset( $alreadyTried[ $code ] ) ) {
884 $message = $this->getMsgFromNamespace(
885 $this->getMessagePageName( $code, $uckey ), $code );
887 if ( $message !== false ) {
890 $alreadyTried[ $code ] = true;
898 * Get the message page name for a given language
900 * @param string $langcode
901 * @param string $uckey Uppercase key for the message
902 * @return string The page name
904 private function getMessagePageName( $langcode, $uckey ) {
905 global $wgLanguageCode;
906 if ( $langcode === $wgLanguageCode ) {
907 // Messages created in the content language will not have the /lang extension
910 return "$uckey/$langcode";
915 * Get a message from the MediaWiki namespace, with caching. The key must
916 * first be converted to two-part lang/msg form if necessary.
918 * Unlike self::get(), this function doesn't resolve fallback chains, and
919 * some callers require this behavior. LanguageConverter::parseCachedTable()
920 * and self::get() are some examples in core.
922 * @param string $title Message cache key with initial uppercase letter.
923 * @param string $code Code denoting the language to try.
924 * @return string|bool The message, or false if it does not exist or on error
926 public function getMsgFromNamespace( $title, $code ) {
927 $this->load( $code );
928 if ( isset( $this->mCache
[$code][$title] ) ) {
929 $entry = $this->mCache
[$code][$title];
930 if ( substr( $entry, 0, 1 ) === ' ' ) {
931 // The message exists, so make sure a string
933 return (string)substr( $entry, 1 );
934 } elseif ( $entry === '!NONEXISTENT' ) {
936 } elseif ( $entry === '!TOO BIG' ) {
937 // Fall through and try invididual message cache below
940 // XXX: This is not cached in process cache, should it?
942 Hooks
::run( 'MessagesPreLoad', [ $title, &$message ] );
943 if ( $message !== false ) {
950 // Try the individual message cache
951 $titleKey = wfMemcKey( 'messages', 'individual', $title );
954 $entry = $this->wanCache
->get(
957 [ wfMemcKey( 'messages', $code ) ]
959 $entry = ( $curTTL >= 0 ) ?
$entry : false;
962 if ( substr( $entry, 0, 1 ) === ' ' ) {
963 $this->mCache
[$code][$title] = $entry;
964 // The message exists, so make sure a string is returned
965 return (string)substr( $entry, 1 );
966 } elseif ( $entry === '!NONEXISTENT' ) {
967 $this->mCache
[$code][$title] = '!NONEXISTENT';
971 // Corrupt/obsolete entry, delete it
972 $this->wanCache
->delete( $titleKey );
976 // Try loading it from the database
977 $dbr = wfGetDB( DB_REPLICA
);
978 $cacheOpts = Database
::getCacheSetOptions( $dbr );
979 // Use newKnownCurrent() to avoid querying revision/user tables
980 $titleObj = Title
::makeTitle( NS_MEDIAWIKI
, $title );
981 if ( $titleObj->getLatestRevID() ) {
982 $revision = Revision
::newKnownCurrent(
984 $titleObj->getArticleID(),
985 $titleObj->getLatestRevID()
992 $content = $revision->getContent();
994 // A possibly temporary loading failure.
997 __METHOD__
. ": failed to load message page text for {$title} ($code)"
999 $message = null; // no negative caching
1001 // XXX: Is this the right way to turn a Content object into a message?
1002 // NOTE: $content is typically either WikitextContent, JavaScriptContent or
1003 // CssContent. MessageContent is *not* used for storing messages, it's
1004 // only used for wrapping them when needed.
1005 $message = $content->getWikitextForTransclusion();
1007 if ( $message === false ||
$message === null ) {
1010 __METHOD__
. ": message content doesn't provide wikitext "
1011 . "(content model: " . $content->getModel() . ")"
1014 $message = false; // negative caching
1016 $this->mCache
[$code][$title] = ' ' . $message;
1017 $this->wanCache
->set( $titleKey, ' ' . $message, $this->mExpiry
, $cacheOpts );
1021 $message = false; // negative caching
1024 if ( $message === false ) { // negative caching
1025 $this->mCache
[$code][$title] = '!NONEXISTENT';
1026 $this->wanCache
->set( $titleKey, '!NONEXISTENT', $this->mExpiry
, $cacheOpts );
1033 * @param string $message
1034 * @param bool $interface
1035 * @param string $language Language code
1036 * @param Title $title
1039 function transform( $message, $interface = false, $language = null, $title = null ) {
1040 // Avoid creating parser if nothing to transform
1041 if ( strpos( $message, '{{' ) === false ) {
1045 if ( $this->mInParser
) {
1049 $parser = $this->getParser();
1051 $popts = $this->getParserOptions();
1052 $popts->setInterfaceMessage( $interface );
1053 $popts->setTargetLanguage( $language );
1055 $userlang = $popts->setUserLang( $language );
1056 $this->mInParser
= true;
1057 $message = $parser->transformMsg( $message, $popts, $title );
1058 $this->mInParser
= false;
1059 $popts->setUserLang( $userlang );
1068 function getParser() {
1069 global $wgParser, $wgParserConf;
1070 if ( !$this->mParser
&& isset( $wgParser ) ) {
1071 # Do some initialisation so that we don't have to do it twice
1072 $wgParser->firstCallInit();
1073 # Clone it and store it
1074 $class = $wgParserConf['class'];
1075 if ( $class == 'ParserDiffTest' ) {
1077 $this->mParser
= new $class( $wgParserConf );
1079 $this->mParser
= clone $wgParser;
1083 return $this->mParser
;
1087 * @param string $text
1088 * @param Title $title
1089 * @param bool $linestart Whether or not this is at the start of a line
1090 * @param bool $interface Whether this is an interface message
1091 * @param Language|string $language Language code
1092 * @return ParserOutput|string
1094 public function parse( $text, $title = null, $linestart = true,
1095 $interface = false, $language = null
1097 if ( $this->mInParser
) {
1098 return htmlspecialchars( $text );
1101 $parser = $this->getParser();
1102 $popts = $this->getParserOptions();
1103 $popts->setInterfaceMessage( $interface );
1105 if ( is_string( $language ) ) {
1106 $language = Language
::factory( $language );
1108 $popts->setTargetLanguage( $language );
1110 if ( !$title ||
!$title instanceof Title
) {
1112 wfDebugLog( 'GlobalTitleFail', __METHOD__
. ' called by ' .
1113 wfGetAllCallers( 6 ) . ' with no title set.' );
1116 // Sometimes $wgTitle isn't set either...
1118 # It's not uncommon having a null $wgTitle in scripts. See r80898
1119 # Create a ghost title in such case
1120 $title = Title
::makeTitle( NS_SPECIAL
, 'Badtitle/title not set in ' . __METHOD__
);
1123 $this->mInParser
= true;
1124 $res = $parser->parse( $text, $title, $popts, $linestart );
1125 $this->mInParser
= false;
1130 function disable() {
1131 $this->mDisable
= true;
1135 $this->mDisable
= false;
1139 * Whether DB/cache usage is disabled for determining messages
1141 * If so, this typically indicates either:
1142 * - a) load() failed to find a cached copy nor query the DB
1143 * - b) we are in a special context or error mode that cannot use the DB
1144 * If the DB is ignored, any derived HTML output or cached objects may be wrong.
1145 * To avoid long-term cache pollution, TTLs can be adjusted accordingly.
1150 public function isDisabled() {
1151 return $this->mDisable
;
1155 * Clear all stored messages. Mainly used after a mass rebuild.
1158 $langs = Language
::fetchLanguageNames( null, 'mw' );
1159 foreach ( array_keys( $langs ) as $code ) {
1160 # Global and local caches
1161 $this->wanCache
->touchCheckKey( wfMemcKey( 'messages', $code ) );
1164 $this->mLoadedLanguages
= [];
1168 * @param string $key
1171 public function figureMessage( $key ) {
1172 global $wgLanguageCode;
1174 $pieces = explode( '/', $key );
1175 if ( count( $pieces ) < 2 ) {
1176 return [ $key, $wgLanguageCode ];
1179 $lang = array_pop( $pieces );
1180 if ( !Language
::fetchLanguageName( $lang, null, 'mw' ) ) {
1181 return [ $key, $wgLanguageCode ];
1184 $message = implode( '/', $pieces );
1186 return [ $message, $lang ];
1190 * Get all message keys stored in the message cache for a given language.
1191 * If $code is the content language code, this will return all message keys
1192 * for which MediaWiki:msgkey exists. If $code is another language code, this
1193 * will ONLY return message keys for which MediaWiki:msgkey/$code exists.
1194 * @param string $code Language code
1195 * @return array Array of message keys (strings)
1197 public function getAllMessageKeys( $code ) {
1199 $this->load( $code );
1200 if ( !isset( $this->mCache
[$code] ) ) {
1201 // Apparently load() failed
1204 // Remove administrative keys
1205 $cache = $this->mCache
[$code];
1206 unset( $cache['VERSION'] );
1207 unset( $cache['EXPIRY'] );
1208 // Remove any !NONEXISTENT keys
1209 $cache = array_diff( $cache, [ '!NONEXISTENT' ] );
1211 // Keys may appear with a capital first letter. lcfirst them.
1212 return array_map( [ $wgContLang, 'lcfirst' ], array_keys( $cache ) );