1.28.3/php/MessageCache_8php_source.html

 <?php

 use MediaWiki\MediaWikiServices;

 use Wikimedia\ScopedCallback;


 define( 'MSG_CACHE_VERSION', 2 );


 class MessageCache {

     const FOR_UPDATE = 1; // force message reload


     const WAIT_SEC = 15;

     const LOCK_TTL = 30;


     protected $mCache;


     protected $mDisable;


     protected $mExpiry;


     protected $mParserOptions, $mParser;


     protected $mLoadedLanguages = [];


     protected $mInParser = false;


     protected $mMemc;

     protected $wanCache;


     private static $instance;


     public static function singleton() {

         if ( self::$instance === null ) {

             global $wgUseDatabaseMessages, $wgMsgCacheExpiry;

             self::$instance = new self(

                 wfGetMessageCacheStorage(),

                 $wgUseDatabaseMessages,

                 $wgMsgCacheExpiry

             );

         }


         return self::$instance;

     }


     public static function destroyInstance() {

         self::$instance = null;

     }


     public static function normalizeKey( $key ) {

         global $wgContLang;

         $lckey = strtr( $key, ' ', '_' );

         if ( ord( $lckey ) < 128 ) {

             $lckey[0] = strtolower( $lckey[0] );

         } else {

             $lckey = $wgContLang->lcfirst( $lckey );

         }


         return $lckey;

     }


     function __construct( $memCached, $useDB, $expiry ) {

         global $wgUseLocalMessageCache;


         if ( !$memCached ) {

             $memCached = wfGetCache( CACHE_NONE );

         }


         $this->mMemc = $memCached;

         $this->mDisable = !$useDB;

         $this->mExpiry = $expiry;


         if ( $wgUseLocalMessageCache ) {

             $this->localCache = MediaWikiServices::getInstance()->getLocalServerObjectCache();

         } else {

             $this->localCache = new EmptyBagOStuff();

         }


         $this->wanCache = ObjectCache::getMainWANInstance();

     }


     function getParserOptions() {

         global $wgUser;


         if ( !$this->mParserOptions ) {

             if ( !$wgUser->isSafeToLoad() ) {

                 // $wgUser isn't unstubbable yet, so don't try to get a

                 // ParserOptions for it. And don't cache this ParserOptions

                 // either.

                 $po = ParserOptions::newFromAnon();

                 $po->setEditSection( false );

                 $po->setAllowUnsafeRawHtml( false );

                 return $po;

             }


             $this->mParserOptions = new ParserOptions;

             $this->mParserOptions->setEditSection( false );

             // Messages may take parameters that could come

             // from malicious sources. As a precaution, disable

             // the <html> parser tag when parsing messages.

             $this->mParserOptions->setAllowUnsafeRawHtml( false );

         }


         return $this->mParserOptions;

     }


     protected function getLocalCache( $code ) {

         $cacheKey = wfMemcKey( __CLASS__, $code );


         return $this->localCache->get( $cacheKey );

     }


     protected function saveToLocalCache( $code, $cache ) {

         $cacheKey = wfMemcKey( __CLASS__, $code );

         $this->localCache->set( $cacheKey, $cache );

     }


     protected function load( $code, $mode = null ) {

         if ( !is_string( $code ) ) {

             throw new InvalidArgumentException( "Missing language code" );

         }


         # Don't do double loading...

         if ( isset( $this->mLoadedLanguages[$code] ) && $mode != self::FOR_UPDATE ) {

             return true;

         }


         # 8 lines of code just to say (once) that message cache is disabled

         if ( $this->mDisable ) {

             static $shownDisabled = false;

             if ( !$shownDisabled ) {

                 wfDebug( __METHOD__ . ": disabled\n" );

                 $shownDisabled = true;

             }


             return true;

         }


         # Loading code starts

         $success = false; # Keep track of success

         $staleCache = false; # a cache array with expired data, or false if none has been loaded

         $where = []; # Debug info, delayed to avoid spamming debug log too much


         # Hash of the contents is stored in memcache, to detect if data-center cache

         # or local cache goes out of date (e.g. due to replace() on some other server)

         list( $hash, $hashVolatile ) = $this->getValidationHash( $code );


         # Try the local cache and check against the cluster hash key...

         $cache = $this->getLocalCache( $code );

         if ( !$cache ) {

             $where[] = 'local cache is empty';

         } elseif ( !isset( $cache['HASH'] ) || $cache['HASH'] !== $hash ) {

             $where[] = 'local cache has the wrong hash';

             $staleCache = $cache;

         } elseif ( $this->isCacheExpired( $cache ) ) {

             $where[] = 'local cache is expired';

             $staleCache = $cache;

         } elseif ( $hashVolatile ) {

             $where[] = 'local cache validation key is expired/volatile';

             $staleCache = $cache;

         } else {

             $where[] = 'got from local cache';

             $success = true;

             $this->mCache[$code] = $cache;

         }


         if ( !$success ) {

             $cacheKey = wfMemcKey( 'messages', $code ); # Key in memc for messages

             # Try the global cache. If it is empty, try to acquire a lock. If

             # the lock can't be acquired, wait for the other thread to finish

             # and then try the global cache a second time.

             for ( $failedAttempts = 0; $failedAttempts <= 1; $failedAttempts++ ) {

                 if ( $hashVolatile && $staleCache ) {

                     # Do not bother fetching the whole cache blob to avoid I/O.

                     # Instead, just try to get the non-blocking $statusKey lock

                     # below, and use the local stale value if it was not acquired.

                     $where[] = 'global cache is presumed expired';

                 } else {

                     $cache = $this->mMemc->get( $cacheKey );

                     if ( !$cache ) {

                         $where[] = 'global cache is empty';

                     } elseif ( $this->isCacheExpired( $cache ) ) {

                         $where[] = 'global cache is expired';

                         $staleCache = $cache;

                     } elseif ( $hashVolatile ) {

                         # DB results are replica DB lag prone until the holdoff TTL passes.

                         # By then, updates should be reflected in loadFromDBWithLock().

                         # One thread renerates the cache while others use old values.

                         $where[] = 'global cache is expired/volatile';

                         $staleCache = $cache;

                     } else {

                         $where[] = 'got from global cache';

                         $this->mCache[$code] = $cache;

                         $this->saveToCaches( $cache, 'local-only', $code );

                         $success = true;

                     }

                 }


                 if ( $success ) {

                     # Done, no need to retry

                     break;

                 }


                 # We need to call loadFromDB. Limit the concurrency to one process.

                 # This prevents the site from going down when the cache expires.

                 # Note that the DB slam protection lock here is non-blocking.

                 $loadStatus = $this->loadFromDBWithLock( $code, $where, $mode );

                 if ( $loadStatus === true ) {

                     $success = true;

                     break;

                 } elseif ( $staleCache ) {

                     # Use the stale cache while some other thread constructs the new one

                     $where[] = 'using stale cache';

                     $this->mCache[$code] = $staleCache;

                     $success = true;

                     break;

                 } elseif ( $failedAttempts > 0 ) {

                     # Already blocked once, so avoid another lock/unlock cycle.

                     # This case will typically be hit if memcached is down, or if

                     # loadFromDB() takes longer than LOCK_WAIT.

                     $where[] = "could not acquire status key.";

                     break;

                 } elseif ( $loadStatus === 'cantacquire' ) {

                     # Wait for the other thread to finish, then retry. Normally,

                     # the memcached get() will then yeild the other thread's result.

                     $where[] = 'waited for other thread to complete';

                     $this->getReentrantScopedLock( $cacheKey );

                 } else {

                     # Disable cache; $loadStatus is 'disabled'

                     break;

                 }

             }

         }


         if ( !$success ) {

             $where[] = 'loading FAILED - cache is disabled';

             $this->mDisable = true;

             $this->mCache = false;

             wfDebugLog( 'MessageCacheError', __METHOD__ . ": Failed to load $code\n" );

             # This used to throw an exception, but that led to nasty side effects like

             # the whole wiki being instantly down if the memcached server died

         } else {

             # All good, just record the success

             $this->mLoadedLanguages[$code] = true;

         }


         $info = implode( ', ', $where );

         wfDebugLog( 'MessageCache', __METHOD__ . ": Loading $code... $info\n" );


         return $success;

     }


     protected function loadFromDBWithLock( $code, array &$where, $mode = null ) {

         global $wgUseLocalMessageCache;


         # If cache updates on all levels fail, give up on message overrides.

         # This is to avoid easy site outages; see $saveSuccess comments below.

         $statusKey = wfMemcKey( 'messages', $code, 'status' );

         $status = $this->mMemc->get( $statusKey );

         if ( $status === 'error' ) {

             $where[] = "could not load; method is still globally disabled";

             return 'disabled';

         }


         # Now let's regenerate

         $where[] = 'loading from database';


         # Lock the cache to prevent conflicting writes.

         # This lock is non-blocking so stale cache can quickly be used.

         # Note that load() will call a blocking getReentrantScopedLock()

         # after this if it really need to wait for any current thread.

         $cacheKey = wfMemcKey( 'messages', $code );

         $scopedLock = $this->getReentrantScopedLock( $cacheKey, 0 );

         if ( !$scopedLock ) {

             $where[] = 'could not acquire main lock';

             return 'cantacquire';

         }


         $cache = $this->loadFromDB( $code, $mode );

         $this->mCache[$code] = $cache;

         $saveSuccess = $this->saveToCaches( $cache, 'all', $code );


         if ( !$saveSuccess ) {

             if ( !$wgUseLocalMessageCache ) {

                 $this->mMemc->set( $statusKey, 'error', 60 * 5 );

                 $where[] = 'could not save cache, disabled globally for 5 minutes';

             } else {

                 $where[] = "could not save global cache";

             }

         }


         return true;

     }


     function loadFromDB( $code, $mode = null ) {

         global $wgMaxMsgCacheEntrySize, $wgLanguageCode, $wgAdaptiveMessageCache;


         $dbr = wfGetDB( ( $mode == self::FOR_UPDATE ) ? DB_MASTER : DB_REPLICA );


         $cache = [];


         # Common conditions

         $conds = [

             'page_is_redirect' => 0,

             'page_namespace' => NS_MEDIAWIKI,

         ];


         $mostused = [];

         if ( $wgAdaptiveMessageCache && $code !== $wgLanguageCode ) {

             if ( !isset( $this->mCache[$wgLanguageCode] ) ) {

                 $this->load( $wgLanguageCode );

             }

             $mostused = array_keys( $this->mCache[$wgLanguageCode] );

             foreach ( $mostused as $key => $value ) {

                 $mostused[$key] = "$value/$code";

             }

         }


         if ( count( $mostused ) ) {

             $conds['page_title'] = $mostused;

         } elseif ( $code !== $wgLanguageCode ) {

             $conds[] = 'page_title' . $dbr->buildLike( $dbr->anyString(), '/', $code );

         } else {

             # Effectively disallows use of '/' character in NS_MEDIAWIKI for uses

             # other than language code.

             $conds[] = 'page_title NOT' . $dbr->buildLike( $dbr->anyString(), '/', $dbr->anyString() );

         }


         # Conditions to fetch oversized pages to ignore them

         $bigConds = $conds;

         $bigConds[] = 'page_len > ' . intval( $wgMaxMsgCacheEntrySize );


         # Load titles for all oversized pages in the MediaWiki namespace

         $res = $dbr->select( 'page', 'page_title', $bigConds, __METHOD__ . "($code)-big" );

         foreach ( $res as $row ) {

             $cache[$row->page_title] = '!TOO BIG';

         }


         # Conditions to load the remaining pages with their contents

         $smallConds = $conds;

         $smallConds[] = 'page_latest=rev_id';

         $smallConds[] = 'rev_text_id=old_id';

         $smallConds[] = 'page_len <= ' . intval( $wgMaxMsgCacheEntrySize );


         $res = $dbr->select(

             [ 'page', 'revision', 'text' ],

             [ 'page_title', 'old_text', 'old_flags' ],

             $smallConds,

             __METHOD__ . "($code)-small"

         );


         foreach ( $res as $row ) {

             $text = Revision::getRevisionText( $row );

             if ( $text === false ) {

                 // Failed to fetch data; possible ES errors?

                 // Store a marker to fetch on-demand as a workaround...

                 $entry = '!TOO BIG';

                 wfDebugLog(

                     'MessageCache',

                     __METHOD__

                         . ": failed to load message page text for {$row->page_title} ($code)"

                 );

             } else {

                 $entry = ' ' . $text;

             }

             $cache[$row->page_title] = $entry;

         }


         $cache['VERSION'] = MSG_CACHE_VERSION;

         ksort( $cache );

         $cache['HASH'] = md5( serialize( $cache ) );

         $cache['EXPIRY'] = wfTimestamp( TS_MW, time() + $this->mExpiry );


         return $cache;

     }


     public function replace( $title, $text ) {

         global $wgMaxMsgCacheEntrySize, $wgContLang, $wgLanguageCode;


         if ( $this->mDisable ) {

             return;

         }


         list( $msg, $code ) = $this->figureMessage( $title );

         if ( strpos( $title, '/' ) !== false && $code === $wgLanguageCode ) {

             // Content language overrides do not use the /<code> suffix

             return;

         }


         // Note that if the cache is volatile, load() may trigger a DB fetch.

         // In that case we reenter/reuse the existing cache key lock to avoid

         // a self-deadlock. This is safe as no reads happen *directly* in this

         // method between getReentrantScopedLock() and load() below. There is

         // no risk of data "changing under our feet" for replace().

         $cacheKey = wfMemcKey( 'messages', $code );

         $scopedLock = $this->getReentrantScopedLock( $cacheKey );

         $this->load( $code, self::FOR_UPDATE );


         $titleKey = wfMemcKey( 'messages', 'individual', $title );

         if ( $text === false ) {

             // Article was deleted

             $this->mCache[$code][$title] = '!NONEXISTENT';

             $this->wanCache->delete( $titleKey );

         } elseif ( strlen( $text ) > $wgMaxMsgCacheEntrySize ) {

             // Check for size

             $this->mCache[$code][$title] = '!TOO BIG';

             $this->wanCache->set( $titleKey, ' ' . $text, $this->mExpiry );

         } else {

             $this->mCache[$code][$title] = ' ' . $text;

             $this->wanCache->delete( $titleKey );

         }


         // Mark this cache as definitely "latest" (non-volatile) so

         // load() calls do try to refresh the cache with replica DB data

         $this->mCache[$code]['LATEST'] = time();


         // Update caches if the lock was acquired

         if ( $scopedLock ) {

             $this->saveToCaches( $this->mCache[$code], 'all', $code );

         }


         ScopedCallback::consume( $scopedLock );

         // Relay the purge to APC and other DCs

         $this->wanCache->touchCheckKey( wfMemcKey( 'messages', $code ) );


         // Also delete cached sidebar... just in case it is affected

         $codes = [ $code ];

         if ( $code === 'en' ) {

             // Delete all sidebars, like for example on action=purge on the

             // sidebar messages

             $codes = array_keys( Language::fetchLanguageNames() );

         }


         foreach ( $codes as $code ) {

             $sidebarKey = wfMemcKey( 'sidebar', $code );

             $this->wanCache->delete( $sidebarKey );

         }


         // Update the message in the message blob store

         $resourceloader = RequestContext::getMain()->getOutput()->getResourceLoader();

         $blobStore = $resourceloader->getMessageBlobStore();

         $blobStore->updateMessage( $wgContLang->lcfirst( $msg ) );


         Hooks::run( 'MessageCacheReplace', [ $title, $text ] );

     }


     protected function isCacheExpired( $cache ) {

         if ( !isset( $cache['VERSION'] ) || !isset( $cache['EXPIRY'] ) ) {

             return true;

         }

         if ( $cache['VERSION'] != MSG_CACHE_VERSION ) {

             return true;

         }

         if ( wfTimestampNow() >= $cache['EXPIRY'] ) {

             return true;

         }


         return false;

     }


     protected function saveToCaches( array $cache, $dest, $code = false ) {

         if ( $dest === 'all' ) {

             $cacheKey = wfMemcKey( 'messages', $code );

             $success = $this->mMemc->set( $cacheKey, $cache );

             $this->setValidationHash( $code, $cache );

         } else {

             $success = true;

         }


         $this->saveToLocalCache( $code, $cache );


         return $success;

     }


     protected function getValidationHash( $code ) {

         $curTTL = null;

         $value = $this->wanCache->get(

             wfMemcKey( 'messages', $code, 'hash', 'v1' ),

             $curTTL,

             [ wfMemcKey( 'messages', $code ) ]

         );


         if ( !$value ) {

             // No hash found at all; cache must regenerate to be safe

             $hash = false;

             $expired = true;

         } else {

             $hash = $value['hash'];

             if ( ( time() - $value['latest'] ) < WANObjectCache::HOLDOFF_TTL ) {

                 // Cache was recently updated via replace() and should be up-to-date

                 $expired = false;

             } else {

                 // See if the "check" key was bumped after the hash was generated

                 $expired = ( $curTTL < 0 );

             }

         }


         return [ $hash, $expired ];

     }


     protected function setValidationHash( $code, array $cache ) {

         $this->wanCache->set(

             wfMemcKey( 'messages', $code, 'hash', 'v1' ),

             [

                 'hash' => $cache['HASH'],

                 'latest' => isset( $cache['LATEST'] ) ? $cache['LATEST'] : 0

             ],

             WANObjectCache::TTL_INDEFINITE

         );

     }


     protected function getReentrantScopedLock( $key, $timeout = self::WAIT_SEC ) {

         return $this->mMemc->getScopedLock( $key, $timeout, self::LOCK_TTL, __METHOD__ );

     }


     function get( $key, $useDB = true, $langcode = true, $isFullKey = false ) {

         if ( is_int( $key ) ) {

             // Fix numerical strings that somehow become ints

             // on their way here

             $key = (string)$key;

         } elseif ( !is_string( $key ) ) {

             throw new MWException( 'Non-string key given' );

         } elseif ( $key === '' ) {

             // Shortcut: the empty key is always missing

             return false;

         }


         // For full keys, get the language code from the key

         $pos = strrpos( $key, '/' );

         if ( $isFullKey && $pos !== false ) {

             $langcode = substr( $key, $pos + 1 );

             $key = substr( $key, 0, $pos );

         }


         // Normalise title-case input (with some inlining)

         $lckey = MessageCache::normalizeKey( $key );


         Hooks::run( 'MessageCache::get', [ &$lckey ] );


         // Loop through each language in the fallback list until we find something useful

         $lang = wfGetLangObj( $langcode );

         $message = $this->getMessageFromFallbackChain(

             $lang,

             $lckey,

             !$this->mDisable && $useDB

         );


         // If we still have no message, maybe the key was in fact a full key so try that

         if ( $message === false ) {

             $parts = explode( '/', $lckey );

             // We may get calls for things that are http-urls from sidebar

             // Let's not load nonexistent languages for those

             // They usually have more than one slash.

             if ( count( $parts ) == 2 && $parts[1] !== '' ) {

                 $message = Language::getMessageFor( $parts[0], $parts[1] );

                 if ( $message === null ) {

                     $message = false;

                 }

             }

         }


         // Post-processing if the message exists

         if ( $message !== false ) {

             // Fix whitespace

             $message = str_replace(

                 [

                     # Fix for trailing whitespace, removed by textarea

                     '&#32;',

                     # Fix for NBSP, converted to space by firefox

                     '&nbsp;',

                     '&#160;',

                     '&shy;'

                 ],

                 [

                     ' ',

                     "\xc2\xa0",

                     "\xc2\xa0",

                     "\xc2\xad"

                 ],

                 $message

             );

         }


         return $message;

     }


     protected function getMessageFromFallbackChain( $lang, $lckey, $useDB ) {

         global $wgContLang;


         $alreadyTried = [];


          // First try the requested language.

         $message = $this->getMessageForLang( $lang, $lckey, $useDB, $alreadyTried );

         if ( $message !== false ) {

             return $message;

         }


         // Now try checking the site language.

         $message = $this->getMessageForLang( $wgContLang, $lckey, $useDB, $alreadyTried );

         return $message;

     }


     private function getMessageForLang( $lang, $lckey, $useDB, &$alreadyTried ) {

         global $wgContLang;

         $langcode = $lang->getCode();


         // Try checking the database for the requested language

         if ( $useDB ) {

             $uckey = $wgContLang->ucfirst( $lckey );


             if ( !isset( $alreadyTried[ $langcode ] ) ) {

                 $message = $this->getMsgFromNamespace(

                     $this->getMessagePageName( $langcode, $uckey ),

                     $langcode

                 );


                 if ( $message !== false ) {

                     return $message;

                 }

                 $alreadyTried[ $langcode ] = true;

             }

         } else {

             $uckey = null;

         }


         // Check the CDB cache

         $message = $lang->getMessage( $lckey );

         if ( $message !== null ) {

             return $message;

         }


         // Try checking the database for all of the fallback languages

         if ( $useDB ) {

             $fallbackChain = Language::getFallbacksFor( $langcode );


             foreach ( $fallbackChain as $code ) {

                 if ( isset( $alreadyTried[ $code ] ) ) {

                     continue;

                 }


                 $message = $this->getMsgFromNamespace(

                     $this->getMessagePageName( $code, $uckey ), $code );


                 if ( $message !== false ) {

                     return $message;

                 }

                 $alreadyTried[ $code ] = true;

             }

         }


         return false;

     }


     private function getMessagePageName( $langcode, $uckey ) {

         global $wgLanguageCode;

         if ( $langcode === $wgLanguageCode ) {

             // Messages created in the content language will not have the /lang extension

             return $uckey;

         } else {

             return "$uckey/$langcode";

         }

     }


     public function getMsgFromNamespace( $title, $code ) {

         $this->load( $code );

         if ( isset( $this->mCache[$code][$title] ) ) {

             $entry = $this->mCache[$code][$title];

             if ( substr( $entry, 0, 1 ) === ' ' ) {

                 // The message exists, so make sure a string

                 // is returned.

                 return (string)substr( $entry, 1 );

             } elseif ( $entry === '!NONEXISTENT' ) {

                 return false;

             } elseif ( $entry === '!TOO BIG' ) {

                 // Fall through and try invididual message cache below

             }

         } else {

             // XXX: This is not cached in process cache, should it?

             $message = false;

             Hooks::run( 'MessagesPreLoad', [ $title, &$message ] );

             if ( $message !== false ) {

                 return $message;

             }


             return false;

         }


         // Try the individual message cache

         $titleKey = wfMemcKey( 'messages', 'individual', $title );


         $curTTL = null;

         $entry = $this->wanCache->get(

             $titleKey,

             $curTTL,

             [ wfMemcKey( 'messages', $code ) ]

         );

         $entry = ( $curTTL >= 0 ) ? $entry : false;


         if ( $entry ) {

             if ( substr( $entry, 0, 1 ) === ' ' ) {

                 $this->mCache[$code][$title] = $entry;

                 // The message exists, so make sure a string is returned

                 return (string)substr( $entry, 1 );

             } elseif ( $entry === '!NONEXISTENT' ) {

                 $this->mCache[$code][$title] = '!NONEXISTENT';


                 return false;

             } else {

                 // Corrupt/obsolete entry, delete it

                 $this->wanCache->delete( $titleKey );

             }

         }


         // Try loading it from the database

         $dbr = wfGetDB( DB_REPLICA );

         $cacheOpts = Database::getCacheSetOptions( $dbr );

         // Use newKnownCurrent() to avoid querying revision/user tables

         $titleObj = Title::makeTitle( NS_MEDIAWIKI, $title );

         if ( $titleObj->getLatestRevID() ) {

             $revision = Revision::newKnownCurrent(

                 $dbr,

                 $titleObj->getArticleID(),

                 $titleObj->getLatestRevID()

             );

         } else {

             $revision = false;

         }


         if ( $revision ) {

             $content = $revision->getContent();

             if ( !$content ) {

                 // A possibly temporary loading failure.

                 wfDebugLog(

                     'MessageCache',

                     __METHOD__ . ": failed to load message page text for {$title} ($code)"

                 );

                 $message = null; // no negative caching

             } else {

                 // XXX: Is this the right way to turn a Content object into a message?

                 // NOTE: $content is typically either WikitextContent, JavaScriptContent or

                 //       CssContent. MessageContent is *not* used for storing messages, it's

                 //       only used for wrapping them when needed.

                 $message = $content->getWikitextForTransclusion();


                 if ( $message === false || $message === null ) {

                     wfDebugLog(

                         'MessageCache',

                         __METHOD__ . ": message content doesn't provide wikitext "

                             . "(content model: " . $content->getModel() . ")"

                     );


                     $message = false; // negative caching

                 } else {

                     $this->mCache[$code][$title] = ' ' . $message;

                     $this->wanCache->set( $titleKey, ' ' . $message, $this->mExpiry, $cacheOpts );

                 }

             }

         } else {

             $message = false; // negative caching

         }


         if ( $message === false ) { // negative caching

             $this->mCache[$code][$title] = '!NONEXISTENT';

             $this->wanCache->set( $titleKey, '!NONEXISTENT', $this->mExpiry, $cacheOpts );

         }


         return $message;

     }


     function transform( $message, $interface = false, $language = null, $title = null ) {

         // Avoid creating parser if nothing to transform

         if ( strpos( $message, '{{' ) === false ) {

             return $message;

         }


         if ( $this->mInParser ) {

             return $message;

         }


         $parser = $this->getParser();

         if ( $parser ) {

             $popts = $this->getParserOptions();

             $popts->setInterfaceMessage( $interface );

             $popts->setTargetLanguage( $language );


             $userlang = $popts->setUserLang( $language );

             $this->mInParser = true;

             $message = $parser->transformMsg( $message, $popts, $title );

             $this->mInParser = false;

             $popts->setUserLang( $userlang );

         }


         return $message;

     }


     function getParser() {

         global $wgParser, $wgParserConf;

         if ( !$this->mParser && isset( $wgParser ) ) {

             # Do some initialisation so that we don't have to do it twice

             $wgParser->firstCallInit();

             # Clone it and store it

             $class = $wgParserConf['class'];

             if ( $class == 'ParserDiffTest' ) {

                 # Uncloneable

                 $this->mParser = new $class( $wgParserConf );

             } else {

                 $this->mParser = clone $wgParser;

             }

         }


         return $this->mParser;

     }


     public function parse( $text, $title = null, $linestart = true,

         $interface = false, $language = null

     ) {

         if ( $this->mInParser ) {

             return htmlspecialchars( $text );

         }


         $parser = $this->getParser();

         $popts = $this->getParserOptions();

         $popts->setInterfaceMessage( $interface );


         if ( is_string( $language ) ) {

             $language = Language::factory( $language );

         }

         $popts->setTargetLanguage( $language );


         if ( !$title || !$title instanceof Title ) {

             global $wgTitle;

             wfDebugLog( 'GlobalTitleFail', __METHOD__ . ' called by ' .

                 wfGetAllCallers( 6 ) . ' with no title set.' );

             $title = $wgTitle;

         }

         // Sometimes $wgTitle isn't set either...

         if ( !$title ) {

             # It's not uncommon having a null $wgTitle in scripts. See r80898

             # Create a ghost title in such case

             $title = Title::makeTitle( NS_SPECIAL, 'Badtitle/title not set in ' . __METHOD__ );

         }


         $this->mInParser = true;

         $res = $parser->parse( $text, $title, $popts, $linestart );

         $this->mInParser = false;


         return $res;

     }


     function disable() {

         $this->mDisable = true;

     }


     function enable() {

         $this->mDisable = false;

     }


     public function isDisabled() {

         return $this->mDisable;

     }


     function clear() {

         $langs = Language::fetchLanguageNames( null, 'mw' );

         foreach ( array_keys( $langs ) as $code ) {

             # Global and local caches

             $this->wanCache->touchCheckKey( wfMemcKey( 'messages', $code ) );

         }


         $this->mLoadedLanguages = [];

     }


     public function figureMessage( $key ) {

         global $wgLanguageCode;


         $pieces = explode( '/', $key );

         if ( count( $pieces ) < 2 ) {

             return [ $key, $wgLanguageCode ];

         }


         $lang = array_pop( $pieces );

         if ( !Language::fetchLanguageName( $lang, null, 'mw' ) ) {

             return [ $key, $wgLanguageCode ];

         }


         $message = implode( '/', $pieces );


         return [ $message, $lang ];

     }


     public function getAllMessageKeys( $code ) {

         global $wgContLang;

         $this->load( $code );

         if ( !isset( $this->mCache[$code] ) ) {

             // Apparently load() failed

             return null;

         }

         // Remove administrative keys

         $cache = $this->mCache[$code];

         unset( $cache['VERSION'] );

         unset( $cache['EXPIRY'] );

         // Remove any !NONEXISTENT keys

         $cache = array_diff( $cache, [ '!NONEXISTENT' ] );


         // Keys may appear with a capital first letter. lcfirst them.

         return array_map( [ $wgContLang, 'lcfirst' ], array_keys( $cache ) );

     }

 }

MessageCache\saveToCaches
saveToCaches(array $cache, $dest, $code=false)
Shortcut to update caches.
Definition: MessageCache.php:633

MessageCache\figureMessage
figureMessage($key)
Definition: MessageCache.php:1176

MessageCache\$mInParser
$mInParser
Definition: MessageCache.php:82

data
and how to run hooks for an and one after Each event has a preferably in CamelCase For ArticleDelete hook A clump of code and data that should be run when an event happens This can be either a function and a chunk of data
Definition: hooks.txt:6

ObjectCache\getMainWANInstance
static getMainWANInstance()
Get the main WAN cache object.
Definition: ObjectCache.php:370

MessageCache\getMessageFromFallbackChain
getMessageFromFallbackChain($lang, $lckey, $useDB)
Given a language, try and fetch messages from that language.
Definition: MessageCache.php:825

list
deferred txt A few of the database updates required by various functions here can be deferred until after the result page is displayed to the user For updating the view updating the linked to tables after a etc PHP does not yet have any way to tell the server to actually return and disconnect while still running these but it might have such a feature in the future We handle these by creating a deferred update object and putting those objects on a global list
Definition: deferred.txt:11

wfGetDB
wfGetDB($db, $groups=[], $wiki=false)
Get a Database object.
Definition: GlobalFunctions.php:3073

MSG_CACHE_VERSION
const MSG_CACHE_VERSION
MediaWiki message cache structure version.
Definition: MessageCache.php:30

array
the array() calling protocol came about after MediaWiki 1.4rc1.

Revision\getRevisionText
static getRevisionText($row, $prefix= 'old_', $wiki=false)
Get revision text associated with an old or archive row $row is usually an object from wfFetchRow()...
Definition: Revision.php:1273

too
I won t presume to tell you how to I m just describing the methods I chose to use for myself If you do choose to follow these it will probably be easier for you to collaborate with others on the but if you want to contribute without by all means do which work well I also use K &R brace matching style I know that s a religious issue for so if you want to use a style that puts opening braces on the next that s OK too
Definition: design.txt:79

IExpiringStore\TTL_INDEFINITE
const TTL_INDEFINITE
Definition: IExpiringStore.php:44

ParserOptions\setEditSection
setEditSection($x)
Definition: ParserOptions.php:504

MessageCache\disable
disable()
Definition: MessageCache.php:1135

$success
$success
Definition: NoLocalSettings.php:44

false
processing should stop and the error should be shown to the user * false
Definition: hooks.txt:189

MessageCache\isCacheExpired
isCacheExpired($cache)
Is the given cache array expired due to time passing or a version change?
Definition: MessageCache.php:610

use
Apache License January AND DISTRIBUTION Definitions License shall mean the terms and conditions for use
Definition: APACHE-LICENSE-2.0.txt:3

Language\getMessageFor
static getMessageFor($key, $code)
Get a message for a given language.
Definition: Language.php:4438

Database\getCacheSetOptions
static getCacheSetOptions(IDatabase $db1)
Merge the result of getSessionLagStatus() for several DBs using the most pessimistic values to estima...
Definition: Database.php:3039

ParserOptions
Set options of the Parser.
Definition: ParserOptions.php:33

$wgParser
$wgParser
Definition: Setup.php:821

of
globals txt Globals are evil The original MediaWiki code relied on globals for processing context far too often MediaWiki development since then has been a story of slowly moving context out of global variables and into objects Storing processing context in object member variables allows those objects to be reused in a much more flexible way Consider the elegance of
database rows
Definition: globals.txt:10

$lang
if(!isset($args[0])) $lang
Definition: testCompression.php:33

MessageCache\destroyInstance
static destroyInstance()
Destroy the singleton instance.
Definition: MessageCache.php:120

in
null for the local wiki Added in
Definition: hooks.txt:1559

string
This code would result in ircNotify being run twice when an article is and once for brion Hooks can return three possible true was required This is the default since MediaWiki *some string
Definition: hooks.txt:177

$value
$value
Definition: styleTest.css.php:45

NS_SPECIAL
const NS_SPECIAL
Definition: Defines.php:45

MediaWikiServices
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency MediaWikiServices
Definition: injection.txt:23

MessageCache\$mParser
$mParser
Definition: MessageCache.php:71

global
when a variable name is used in a it is silently declared as a new local masking the global
Definition: design.txt:93

Language\getFallbacksFor
static getFallbacksFor($code)
Get the ordered list of fallback languages.
Definition: Language.php:4378

$parser
magic word & $parser
Definition: hooks.txt:2491

wfGetMessageCacheStorage
wfGetMessageCacheStorage()
Get the cache object used by the message cache.
Definition: GlobalFunctions.php:3430

DB_MASTER
const DB_MASTER
Definition: defines.php:23

MessageCache
Message cache Performs various MediaWiki namespace-related functions.
Definition: MessageCache.php:37

MessageCache\transform
transform($message, $interface=false, $language=null, $title=null)
Definition: MessageCache.php:1044

$wgUseLocalMessageCache
$wgUseLocalMessageCache
Set this to true to maintain a copy of the message cache on the local server.
Definition: DefaultSettings.php:2447

MessageCache\getMsgFromNamespace
getMsgFromNamespace($title, $code)
Get a message from the MediaWiki namespace, with caching.
Definition: MessageCache.php:931

ScopedCallback

wfDebug
wfDebug($text, $dest= 'all', array $context=[])
Sends a line to the debug log if enabled or, optionally, to a comment in output.
Definition: GlobalFunctions.php:997

Language\fetchLanguageNames
static fetchLanguageNames($inLanguage=null, $include= 'mw')
Get an array of language names, indexed by code.
Definition: Language.php:800

MessageCache\getParserOptions
getParserOptions()
ParserOptions is lazy initialised.
Definition: MessageCache.php:172

$dbr
$dbr
Definition: testCompression.php:50

MessageCache\getLocalCache
getLocalCache($code)
Try to load the cache from APC.
Definition: MessageCache.php:203

messages
passed in as a query string parameter to the various URLs constructed here(i.e.$prevlink) $ldel you ll need to handle error messages
Definition: hooks.txt:1234

cache
you have access to all of the normal MediaWiki so you can get a DB use the cache
Definition: maintenance.txt:52

wfTimestamp
wfTimestamp($outputtype=TS_UNIX, $ts=0)
Get a timestamp string in one of various formats.
Definition: GlobalFunctions.php:2007

MessageCache\normalizeKey
static normalizeKey($key)
Normalize message key input.
Definition: MessageCache.php:130

$wgLanguageCode
$wgLanguageCode
Site language code.
Definition: DefaultSettings.php:2828

wfDebugLog
wfDebugLog($logGroup, $text, $dest= 'all', array $context=[])
Send a line to a supplementary debug log file, if configured, or main debug log if not...
Definition: GlobalFunctions.php:1090

MessageCache\saveToLocalCache
saveToLocalCache($code, $cache)
Save the cache to APC.
Definition: MessageCache.php:215

$wgMaxMsgCacheEntrySize
$wgMaxMsgCacheEntrySize
Maximum entry size in the message cache, in bytes.
Definition: DefaultSettings.php:3026

RequestContext\getMain
static getMain()
Static methods.
Definition: RequestContext.php:468

wfGetCache
wfGetCache($cacheType)
Get a specific cache object.
Definition: GlobalFunctions.php:3411

$wgAdaptiveMessageCache
$wgAdaptiveMessageCache
Instead of caching everything, only cache those messages which have been customised in the site conte...
Definition: DefaultSettings.php:2455

$res
$res
Definition: database.txt:21

$wgUseDatabaseMessages
$wgUseDatabaseMessages
Translation using MediaWiki: namespace.
Definition: DefaultSettings.php:3016

wfTimestampNow
wfTimestampNow()
Convenience function; returns MediaWiki timestamp for the present time.
Definition: GlobalFunctions.php:2036

MessageCache\getParser
getParser()
Definition: MessageCache.php:1073

$cache
$cache
Definition: mcc.php:33

MessageCache\$mParserOptions
$mParserOptions
Message cache has its own parser which it uses to transform messages.
Definition: MessageCache.php:71

TS_MW
const TS_MW
MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
Definition: defines.php:11

MessageCache\$mLoadedLanguages
$mLoadedLanguages
Variable for tracking which variables are already loaded.
Definition: MessageCache.php:77

$title
namespace and then decline to actually register it file or subcat img or subcat $title
Definition: hooks.txt:957

Revision\newKnownCurrent
static newKnownCurrent(IDatabase $db, $pageId, $revId)
Load a revision based on a known page ID and current revision ID from the DB.
Definition: Revision.php:1905

MessageCache\$instance
static $instance
Singleton instance.
Definition: MessageCache.php:94

EmptyBagOStuff
A BagOStuff object with no objects in it.
Definition: EmptyBagOStuff.php:29

MessageCache\getAllMessageKeys
getAllMessageKeys($code)
Get all message keys stored in the message cache for a given language.
Definition: MessageCache.php:1202

Hooks\run
static run($event, array $args=[], $deprecatedVersion=null)
Call hook functions defined in Hooks::register and $wgHooks.
Definition: Hooks.php:131

MessageCache\getValidationHash
getValidationHash($code)
Get the md5 used to validate the local APC cache.
Definition: MessageCache.php:653

by
Apache License January AND DISTRIBUTION Definitions License shall mean the terms and conditions for and distribution as defined by Sections through of this document Licensor shall mean the copyright owner or entity authorized by the copyright owner that is granting the License Legal Entity shall mean the union of the acting entity and all other entities that control are controlled by or are under common control with that entity For the purposes of this definition control direct or to cause the direction or management of such whether by contract or including but not limited to software source documentation and configuration files Object form shall mean any form resulting from mechanical transformation or translation of a Source including but not limited to compiled object generated and conversions to other media types Work shall mean the work of whether in Source or Object made available under the as indicated by a copyright notice that is included in or attached to the whether in Source or Object that is based or other modifications as a an original work of authorship For the purposes of this Derivative Works shall not include works that remain separable or merely the Work and Derivative Works thereof Contribution shall mean any work of including the original version of the Work and any modifications or additions to that Work or Derivative Works that is intentionally submitted to Licensor for inclusion in the Work by the copyright owner or by an individual or Legal Entity authorized to submit on behalf of the copyright owner For the purposes of this submitted means any form of or written communication sent to the Licensor or its including but not limited to communication on electronic mailing source code control and issue tracking systems that are managed by
Definition: APACHE-LICENSE-2.0.txt:49

as
This document is intended to provide useful advice for parties seeking to redistribute MediaWiki to end users It s targeted particularly at maintainers for Linux since it s been observed that distribution packages of MediaWiki often break We ve consistently had to recommend that users seeking support use official tarballs instead of their distribution s and this often solves whatever problem the user is having It would be nice if this could such as
Definition: distributors.txt:9

$code
this hook is for auditing only or null if authentication failed before getting that far or null if we can t even determine that probably a stub it is not rendered in wiki pages or galleries in category pages allow injecting custom HTML after the section Any uses of the hook need to handle escaping see BaseTemplate::getToolbox and BaseTemplate::makeListItem for details on the format of individual items inside of this array or by returning and letting standard HTTP rendering take place modifiable or by returning false and taking over the output modifiable & $code
Definition: hooks.txt:806

NS_MEDIAWIKI
const NS_MEDIAWIKI
Definition: Defines.php:64

Language\fetchLanguageName
static fetchLanguageName($code, $inLanguage=null, $include= 'all')
Definition: Language.php:888

ParserOptions\newFromAnon
static newFromAnon()
Get a ParserOptions object for an anonymous user.
Definition: ParserOptions.php:693

MessageCache\__construct
__construct($memCached, $useDB, $expiry)
Definition: MessageCache.php:147

info
this hook is for auditing only RecentChangesLinked and Watchlist RecentChangesLinked and Watchlist e g Watchlist removed from all revisions and log entries to which it was applied This gives extensions a chance to take it off their books as the deletion has already been partly carried out by this point or something similar the user will be unable to create the tag set and then return false from the hook function Ensure you consume the ChangeTagAfterDelete hook to carry out custom deletion actions as context called by AbstractContent::getParserOutput May be used to override the normal model specific rendering of page content as context as context the output can only depend on parameters provided to this hook not on global state indicating whether full HTML should be generated If generation of HTML may be but other information should still be present in the ParserOutput object to manipulate or replace but no entry for that model exists in $wgContentHandlers if desired whether it is OK to use $contentModel on $title Handler functions that modify $ok should generally return false to prevent further hooks from further modifying $ok inclusive false for true for descending in case the handler function wants to provide a converted Content object Note that $result getContentModel() must return $toModel. 'CustomEditor'$rcid is used in generating this variable which contains information about the new such as the revision s whether the revision was marked as a minor edit or etc which include things like revision author info
Definition: hooks.txt:1160

MessageCache\WAIT_SEC
const WAIT_SEC
How long to wait for memcached locks.
Definition: MessageCache.php:41

MessageCache\load
load($code, $mode=null)
Loads messages from caches or from database in this order: (1) local message cache (if $wgUseLocalMes...
Definition: MessageCache.php:241

or
or
Definition: APACHE-LICENSE-2.0.txt:114

WANObjectCache\HOLDOFF_TTL
const HOLDOFF_TTL
Seconds to tombstone keys on delete()
Definition: WANObjectCache.php:101

wfGetAllCallers
wfGetAllCallers($limit=3)
Return a string consisting of callers in the stack.
Definition: GlobalFunctions.php:1589

MessageCache\FOR_UPDATE
const FOR_UPDATE
Definition: MessageCache.php:38

MessageCache\isDisabled
isDisabled()
Whether DB/cache usage is disabled for determining messages.
Definition: MessageCache.php:1155

php
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency which acts as the top level factory for services in MediaWiki which can be used to gain access to default instances of various services MediaWikiServices however also allows new services to be defined and default services to be redefined Services are defined or redefined by providing a callback the instantiator that will return a new instance of the service When it will create an instance of MediaWikiServices and populate it with the services defined in the files listed by thereby bootstrapping the DI framework Per $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:35

MessageCache\$mExpiry
$mExpiry
Lifetime for cache, used by object caching.
Definition: MessageCache.php:65

MessageCache\parse
parse($text, $title=null, $linestart=true, $interface=false, $language=null)
Definition: MessageCache.php:1099

$content
this hook is for auditing only RecentChangesLinked and Watchlist RecentChangesLinked and Watchlist e g Watchlist removed from all revisions and log entries to which it was applied This gives extensions a chance to take it off their books as the deletion has already been partly carried out by this point or something similar the user will be unable to create the tag set and then return false from the hook function Ensure you consume the ChangeTagAfterDelete hook to carry out custom deletion actions as context called by AbstractContent::getParserOutput May be used to override the normal model specific rendering of page content $content
Definition: hooks.txt:1050

$wgMsgCacheExpiry
$wgMsgCacheExpiry
Expiry time for the message cache key.
Definition: DefaultSettings.php:3021

MessageCache\$mCache
$mCache
Process local cache of loaded messages that are defined in MediaWiki namespace.
Definition: MessageCache.php:53

MessageCache\loadFromDBWithLock
loadFromDBWithLock($code, array &$where, $mode=null)
Definition: MessageCache.php:382

$wgContLang
this class mediates it Skin Encapsulates a look and feel for the wiki All of the functions that render HTML and make choices about how to render it are here and are called from various other places when and is meant to be subclassed with other skins that may override some of its functions The User object contains a reference to a and so rather than having a global skin object we just rely on the global User and get the skin with $wgUser and also has some character encoding functions and other locale stuff The current user interface language is instantiated as and the local content language as $wgContLang
Definition: design.txt:56

MessageCache\getReentrantScopedLock
getReentrantScopedLock($key, $timeout=self::WAIT_SEC)
Definition: MessageCache.php:704

$status
this hook is for auditing only RecentChangesLinked and Watchlist RecentChangesLinked and Watchlist e g Watchlist removed from all revisions and log entries to which it was applied This gives extensions a chance to take it off their books as the deletion has already been partly carried out by this point or something similar the user will be unable to create the tag set $status
Definition: hooks.txt:1050

MessageCache\loadFromDB
loadFromDB($code, $mode=null)
Loads cacheable messages from the database.
Definition: MessageCache.php:446

MessageCache\clear
clear()
Clear all stored messages.
Definition: MessageCache.php:1162

MessageCache\setValidationHash
setValidationHash($code, array $cache)
Set the md5 used to validate the local disk cache.
Definition: MessageCache.php:688

wfMemcKey
wfMemcKey()
Make a cache key for the local wiki.
Definition: GlobalFunctions.php:2974

DB_REPLICA
const DB_REPLICA
Definition: defines.php:22

InvalidArgumentException

serialize
serialize()
Definition: ApiMessage.php:94

$wgTitle
if(!$wgRequest->checkUrlExtension()) if(isset($_SERVER['PATH_INFO'])&&$_SERVER['PATH_INFO']!= '') if(!$wgEnableAPI) $wgTitle
Definition: api.php:68

MessageCache\$mDisable
$mDisable
Should mean that database cannot be used, but check.
Definition: MessageCache.php:59

Title

CACHE_NONE
const CACHE_NONE
Definition: Defines.php:94

Language\factory
static factory($code)
Get a cached or new language object for a given language code.
Definition: Language.php:181

MessageCache\getMessageForLang
getMessageForLang($lang, $lckey, $useDB, &$alreadyTried)
Given a language, try and fetch messages from that language and its fallbacks.
Definition: MessageCache.php:851

MessageCache\$wanCache
WANObjectCache $wanCache
Definition: MessageCache.php:87

Title\makeTitle
static makeTitle($ns, $title, $fragment= '', $interwiki= '')
Create a new Title from a namespace index and a DB key.
Definition: Title.php:511

MWException

MessageCache\$mMemc
BagOStuff $mMemc
Definition: MessageCache.php:85

MessageCache\LOCK_TTL
const LOCK_TTL
How long memcached locks last.
Definition: MessageCache.php:43

MessageCache\singleton
static singleton()
Get the signleton instance of this class.
Definition: MessageCache.php:102

MessageCache\replace
replace($title, $text)
Updates cache as necessary when message page is changed.
Definition: MessageCache.php:534

MessageCache\getMessagePageName
getMessagePageName($langcode, $uckey)
Get the message page name for a given language.
Definition: MessageCache.php:909

wfGetLangObj
wfGetLangObj($langcode=false)
Return a Language object from $langcode.
Definition: GlobalFunctions.php:1337

MessageCache\enable
enable()
Definition: MessageCache.php:1139

$wgUser
$wgUser
Definition: Setup.php:806