REL1_31/php/MessageCache_8php_source.html

<?php

use MediaWiki\MediaWikiServices;

use Wikimedia\ScopedCallback;

use MediaWiki\Logger\LoggerFactory;

use Wikimedia\Rdbms\Database;


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 $mCacheVolatile = [];


    protected $mDisable;


    protected $mExpiry;


    protected $mParserOptions;

    protected $mParser;


    protected $mLoadedLanguages = [];


    protected $mInParser = false;


    protected $wanCache;

    protected $clusterCache;

    protected $srvCache;


    private static $instance;


    public static function singleton() {

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

            global $wgUseDatabaseMessages, $wgMsgCacheExpiry, $wgUseLocalMessageCache;

            self::$instance = new self(

                MediaWikiServices::getInstance()->getMainWANObjectCache(),

                wfGetMessageCacheStorage(),

                $wgUseLocalMessageCache

                    ? MediaWikiServices::getInstance()->getLocalServerObjectCache()

                    : new EmptyBagOStuff(),

                $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;

    }


    public function __construct(

        WANObjectCache $wanCache,

        BagOStuff $clusterCache,

        BagOStuff $serverCache,

        $useDB,

        $expiry

    ) {

        $this->wanCache = $wanCache;

        $this->clusterCache = $clusterCache;

        $this->srvCache = $serverCache;


        $this->mDisable = !$useDB;

        $this->mExpiry = $expiry;

    }


    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->setAllowUnsafeRawHtml( false );

                return $po;

            }


            $this->mParserOptions = new ParserOptions;

            // 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 = $this->srvCache->makeKey( __CLASS__, $code );


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

    }


    protected function saveToLocalCache( $code, $cache ) {

        $cacheKey = $this->srvCache->makeKey( __CLASS__, $code );

        $this->srvCache->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 );

        $this->mCacheVolatile[$code] = $hashVolatile;


        # 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 = $this->clusterCache->makeKey( 'messages', $code );

            # 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->clusterCache->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 ) {

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

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

        $statusKey = $this->clusterCache->makeKey( 'messages', $code, 'status' );

        $status = $this->clusterCache->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 = $this->clusterCache->makeKey( '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 ( $this->srvCache instanceof EmptyBagOStuff ) {

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

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

            } else {

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

            }

        }


        return true;

    }


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

        global $wgMaxMsgCacheEntrySize, $wgLanguageCode, $wgAdaptiveMessageCache;


        // (T164666) The query here performs really poorly on WMF's

        // contributions replicas. We don't have a way to say "any group except

        // contributions", so for the moment let's specify 'api'.

        // @todo: Get rid of this hack.

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


        $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', 'page_latest' ],

            $bigConds,

            __METHOD__ . "($code)-big"

        );

        foreach ( $res as $row ) {

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

            // At least include revision ID so page changes are reflected in the hash

            $cache['EXCESSIVE'][$row->page_title] = $row->page_latest;

        }


        # Conditions to load the remaining pages with their contents

        $smallConds = $conds;

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


        $res = $dbr->select(

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

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

            $smallConds,

            __METHOD__ . "($code)-small",

            [],

            [

                'revision' => [ 'JOIN', 'page_latest=rev_id' ],

                'text' => [ 'JOIN', 'rev_text_id=old_id' ],

            ]

        );


        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...

                // TODO Use a differnt marker

                $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 );


        # Hash for validating local cache (APC). No need to take into account

        # messages larger than $wgMaxMsgCacheEntrySize, since those are only

        # stored and fetched from memcache.

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

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


        return $cache;

    }


    public function replace( $title, $text ) {

        global $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;

        }


        // (a) Update the process cache with the new message text

        if ( $text === false ) {

            // Page deleted

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

        } else {

            // Ignore $wgMaxMsgCacheEntrySize so the process cache is up to date

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

        }


        // (b) Update the shared caches in a deferred update with a fresh DB snapshot

        DeferredUpdates::addCallableUpdate(

            function () use ( $title, $msg, $code ) {

                global $wgContLang, $wgMaxMsgCacheEntrySize;

                // Allow one caller at a time to avoid race conditions

                $scopedLock = $this->getReentrantScopedLock(

                    $this->clusterCache->makeKey( 'messages', $code )

                );

                if ( !$scopedLock ) {

                    LoggerFactory::getInstance( 'MessageCache' )->error(

                        __METHOD__ . ': could not acquire lock to update {title} ({code})',

                        [ 'title' => $title, 'code' => $code ] );

                    return;

                }

                // Load the messages from the master DB to avoid race conditions

                $cache = $this->loadFromDB( $code, self::FOR_UPDATE );

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

                // Load the process cache values and set the per-title cache keys

                $page = WikiPage::factory( Title::makeTitle( NS_MEDIAWIKI, $title ) );

                $page->loadPageData( $page::READ_LATEST );

                $text = $this->getMessageTextFromContent( $page->getContent() );

                // Check if an individual cache key should exist and update cache accordingly

                if ( is_string( $text ) && strlen( $text ) > $wgMaxMsgCacheEntrySize ) {

                    $titleKey = $this->bigMessageCacheKey( $this->mCache[$code]['HASH'], $title );

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

                }

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

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

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

                // Pre-emptively update the local datacenter cache so things like edit filter and

                // blacklist changes are reflected immediately; these often use MediaWiki: pages.

                // The datacenter handling replace() calls should be the same one handling edits

                // as they require HTTP POST.

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

                // Release the lock now that the cache is saved

                ScopedCallback::consume( $scopedLock );


                // Relay the purge. Touching this check key expires cache contents

                // and local cache (APC) validation hash across all datacenters.

                $this->wanCache->touchCheckKey( $this->getCheckKey( $code ) );


                // Purge 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 ] );

            },

            DeferredUpdates::PRESEND

        );

    }


    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 = $this->clusterCache->makeKey( 'messages', $code );

            $success = $this->clusterCache->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(

            $this->wanCache->makeKey( 'messages', $code, 'hash', 'v1' ),

            $curTTL,

            [ $this->getCheckKey( $code ) ]

        );


        if ( $value ) {

            $hash = $value['hash'];

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

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

                // That method is only called in the primary datacenter and uses FOR_UPDATE.

                // Also, it is unlikely that the current datacenter is *now* secondary one.

                $expired = false;

            } else {

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

                $expired = ( $curTTL < 0 );

            }

        } else {

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

            $hash = false;

            $expired = true;

        }


        return [ $hash, $expired ];

    }


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

        $this->wanCache->set(

            $this->wanCache->makeKey( '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->clusterCache->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 = self::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 and is not '!TOO BIG'

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

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

                return false;

            }

            // 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, $code ] );

            if ( $message !== false ) {

                return $message;

            }


            return false;

        }


        // Individual message cache key

        $titleKey = $this->bigMessageCacheKey( $this->mCache[$code]['HASH'], $title );


        if ( $this->mCacheVolatile[$code] ) {

            $entry = false;

            // Make sure that individual keys respect the WAN cache holdoff period too

            LoggerFactory::getInstance( 'MessageCache' )->debug(

                __METHOD__ . ': loading volatile key \'{titleKey}\'',

                [ 'titleKey' => $titleKey, 'code' => $code ] );

        } else {

            // Try the individual message cache

            $entry = $this->wanCache->get( $titleKey );

        }


        if ( $entry !== false ) {

            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 the message 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

            );

        } else {

            $revision = false;

        }


        if ( $revision ) {

            $content = $revision->getContent();

            if ( $content ) {

                $message = $this->getMessageTextFromContent( $content );

                if ( is_string( $message ) ) {

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

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

                }

            } else {

                // A possibly temporary loading failure

                LoggerFactory::getInstance( 'MessageCache' )->warning(

                    __METHOD__ . ': failed to load message page text for \'{titleKey}\'',

                    [ 'titleKey' => $titleKey, 'code' => $code ] );

                $message = null; // no negative caching

            }

        } else {

            $message = false; // negative caching

        }


        if ( $message === false ) {

            // Negative caching in case a "too big" message is no longer available (deleted)

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

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

        }


        return $message;

    }


    public 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;

    }


    public 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::class ) {

                # 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

    ) {

        global $wgTitle;


        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 ) {

            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;

    }


    public function disable() {

        $this->mDisable = true;

    }


    public function enable() {

        $this->mDisable = false;

    }


    public function isDisabled() {

        return $this->mDisable;

    }


    function clear() {

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

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

            $this->wanCache->touchCheckKey( $this->getCheckKey( $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'] );

        unset( $cache['EXCESSIVE'] );

        // 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 ) );

    }


    public function updateMessageOverride( Title $title, Content $content = null ) {

        global $wgContLang;


        $msgText = $this->getMessageTextFromContent( $content );

        if ( $msgText === null ) {

            $msgText = false; // treat as not existing

        }


        $this->replace( $title->getDBkey(), $msgText );


        if ( $wgContLang->hasVariants() ) {

            $wgContLang->updateConversionTable( $title );

        }

    }


    public function getCheckKey( $code ) {

        return $this->wanCache->makeKey( 'messages', $code );

    }


    private function getMessageTextFromContent( Content $content = null ) {

        // @TODO: could skip pseudo-messages like js/css here, based on content model

        if ( $content ) {

            // Message page exists...

            // 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.

            $msgText = $content->getWikitextForTransclusion();

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

                // This might be due to some kind of misconfiguration...

                $msgText = null;

                LoggerFactory::getInstance( 'MessageCache' )->warning(

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

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

            }

        } else {

            // Message page does not exist...

            $msgText = false;

        }


        return $msgText;

    }


    private function bigMessageCacheKey( $hash, $title ) {

        return $this->wanCache->makeKey( 'messages-big', $hash, $title );

    }


}


serialize
serialize()
Definition ApiMessage.php:184

$wgLanguageCode
$wgLanguageCode
Site language code.
Definition DefaultSettings.php:2887

$wgUseLocalMessageCache
$wgUseLocalMessageCache
Set this to true to maintain a copy of the message cache on the local server.
Definition DefaultSettings.php:2503

$wgAdaptiveMessageCache
$wgAdaptiveMessageCache
Instead of caching everything, only cache those messages which have been customised in the site conte...
Definition DefaultSettings.php:2511

$wgUseDatabaseMessages
$wgUseDatabaseMessages
Translation using MediaWiki: namespace.
Definition DefaultSettings.php:3043

$wgMaxMsgCacheEntrySize
$wgMaxMsgCacheEntrySize
Maximum entry size in the message cache, in bytes.
Definition DefaultSettings.php:3053

$wgParserConf
$wgParserConf
Parser configuration.
Definition DefaultSettings.php:4170

$wgMsgCacheExpiry
$wgMsgCacheExpiry
Expiry time for the message cache key.
Definition DefaultSettings.php:3048

wfGetLangObj
wfGetLangObj( $langcode=false)
Return a Language object from $langcode.
Definition GlobalFunctions.php:1306

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:994

wfTimestampNow
wfTimestampNow()
Convenience function; returns MediaWiki timestamp for the present time.
Definition GlobalFunctions.php:2009

wfGetDB
wfGetDB( $db, $groups=[], $wiki=false)
Get a Database object.
Definition GlobalFunctions.php:2812

wfGetMessageCacheStorage
wfGetMessageCacheStorage()
Get the cache object used by the message cache.
Definition GlobalFunctions.php:3157

wfGetAllCallers
wfGetAllCallers( $limit=3)
Return a string consisting of callers in the stack.
Definition GlobalFunctions.php:1563

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:1087

wfTimestamp
wfTimestamp( $outputtype=TS_UNIX, $ts=0)
Get a timestamp string in one of various formats.
Definition GlobalFunctions.php:1980

MSG_CACHE_VERSION
const MSG_CACHE_VERSION
MediaWiki message cache structure version.
Definition MessageCache.php:32

$success
$success
Definition NoLocalSettings.php:42

$wgUser
$wgUser
Definition Setup.php:902

$wgParser
$wgParser
Definition Setup.php:917

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

BagOStuff
interface is intended to be more or less compatible with the PHP memcached client.
Definition BagOStuff.php:47

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

MWException
MediaWiki exception.
Definition MWException.php:26

MediaWiki\Logger\LoggerFactory
PSR-3 logger instance factory.
Definition LoggerFactory.php:45

MediaWiki\MediaWikiServices
MediaWikiServices is the service locator for the application scope of MediaWiki.
Definition MediaWikiServices.php:88

MessageCache
Message cache Performs various MediaWiki namespace-related functions.
Definition MessageCache.php:39

MessageCache\getValidationHash
getValidationHash( $code)
Get the md5 used to validate the local APC cache.
Definition MessageCache.php:687

MessageCache\loadFromDBWithLock
loadFromDBWithLock( $code, array &$where, $mode=null)
Definition MessageCache.php:394

MessageCache\LOCK_TTL
const LOCK_TTL
How long memcached locks last.
Definition MessageCache.php:45

MessageCache\loadFromDB
loadFromDB( $code, $mode=null)
Loads cacheable messages from the database.
Definition MessageCache.php:456

MessageCache\getMessageForLang
getMessageForLang( $lang, $lckey, $useDB, &$alreadyTried)
Given a language, try and fetch messages from that language and its fallbacks.
Definition MessageCache.php:888

MessageCache\$mExpiry
$mExpiry
Lifetime for cache, used by object caching.
Definition MessageCache.php:72

MessageCache\saveToLocalCache
saveToLocalCache( $code, $cache)
Save the cache to APC.
Definition MessageCache.php:226

MessageCache\getMessagePageName
getMessagePageName( $langcode, $uckey)
Get the message page name for a given language.
Definition MessageCache.php:947

MessageCache\$instance
static $instance
Singleton instance.
Definition MessageCache.php:105

MessageCache\getCheckKey
getCheckKey( $code)
Definition MessageCache.php:1278

MessageCache\$mParser
Parser $mParser
Definition MessageCache.php:80

MessageCache\saveToCaches
saveToCaches(array $cache, $dest, $code=false)
Shortcut to update caches.
Definition MessageCache.php:667

MessageCache\$mInParser
$mInParser
Definition MessageCache.php:91

MessageCache\setValidationHash
setValidationHash( $code, array $cache)
Set the md5 used to validate the local disk cache.
Definition MessageCache.php:725

MessageCache\$mCacheVolatile
bool[] $mCacheVolatile
Map of (language code => boolean)
Definition MessageCache.php:60

MessageCache\isCacheExpired
isCacheExpired( $cache)
Is the given cache array expired due to time passing or a version change?
Definition MessageCache.php:644

MessageCache\getMsgFromNamespace
getMsgFromNamespace( $title, $code)
Get a message from the MediaWiki namespace, with caching.
Definition MessageCache.php:970

MessageCache\getReentrantScopedLock
getReentrantScopedLock( $key, $timeout=self::WAIT_SEC)
Definition MessageCache.php:741

MessageCache\WAIT_SEC
const WAIT_SEC
How long to wait for memcached locks.
Definition MessageCache.php:43

MessageCache\$mDisable
$mDisable
Should mean that database cannot be used, but check.
Definition MessageCache.php:66

MessageCache\getLocalCache
getLocalCache( $code)
Try to load the cache from APC.
Definition MessageCache.php:214

MessageCache\destroyInstance
static destroyInstance()
Destroy the singleton instance.
Definition MessageCache.php:135

MessageCache\__construct
__construct(WANObjectCache $wanCache, BagOStuff $clusterCache, BagOStuff $serverCache, $useDB, $expiry)
Definition MessageCache.php:165

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:252

MessageCache\$srvCache
BagOStuff $srvCache
Definition MessageCache.php:98

MessageCache\transform
transform( $message, $interface=false, $language=null, $title=null)
Definition MessageCache.php:1071

MessageCache\updateMessageOverride
updateMessageOverride(Title $title, Content $content=null)
Purge message caches when a MediaWiki: page is created, updated, or deleted.
Definition MessageCache.php:1259

MessageCache\getMessageFromFallbackChain
getMessageFromFallbackChain( $lang, $lckey, $useDB)
Given a language, try and fetch messages from that language.
Definition MessageCache.php:862

MessageCache\$mLoadedLanguages
$mLoadedLanguages
Variable for tracking which variables are already loaded.
Definition MessageCache.php:86

MessageCache\isDisabled
isDisabled()
Whether DB/cache usage is disabled for determining messages.
Definition MessageCache.php:1184

MessageCache\disable
disable()
Definition MessageCache.php:1164

MessageCache\$clusterCache
BagOStuff $clusterCache
Definition MessageCache.php:96

MessageCache\getParser
getParser()
Definition MessageCache.php:1100

MessageCache\getMessageTextFromContent
getMessageTextFromContent(Content $content=null)
Definition MessageCache.php:1286

MessageCache\clear
clear()
Clear all stored messages in global and local cache.
Definition MessageCache.php:1193

MessageCache\singleton
static singleton()
Get the signleton instance of this class.
Definition MessageCache.php:113

MessageCache\getAllMessageKeys
getAllMessageKeys( $code)
Get all message keys stored in the message cache for a given language.
Definition MessageCache.php:1232

MessageCache\$mCache
$mCache
Process local cache of loaded messages that are defined in MediaWiki namespace.
Definition MessageCache.php:55

MessageCache\$wanCache
WANObjectCache $wanCache
Definition MessageCache.php:94

MessageCache\normalizeKey
static normalizeKey( $key)
Normalize message key input.
Definition MessageCache.php:145

MessageCache\FOR_UPDATE
const FOR_UPDATE
Definition MessageCache.php:40

MessageCache\enable
enable()
Definition MessageCache.php:1168

MessageCache\figureMessage
figureMessage( $key)
Definition MessageCache.php:1206

MessageCache\parse
parse( $text, $title=null, $linestart=true, $interface=false, $language=null)
Definition MessageCache.php:1127

MessageCache\$mParserOptions
ParserOptions $mParserOptions
Message cache has its own parser which it uses to transform messages.
Definition MessageCache.php:78

MessageCache\replace
replace( $title, $text)
Updates cache as necessary when message page is changed.
Definition MessageCache.php:564

MessageCache\getParserOptions
getParserOptions()
ParserOptions is lazy initialised.
Definition MessageCache.php:185

MessageCache\bigMessageCacheKey
bigMessageCacheKey( $hash, $title)
Definition MessageCache.php:1315

ParserOptions
Set options of the Parser.
Definition ParserOptions.php:40

ParserOptions\setAllowUnsafeRawHtml
setAllowUnsafeRawHtml( $x)
If the wiki is configured to allow raw html ($wgRawHtml = true) is it allowed in the specific case of...
Definition ParserOptions.php:759

Parser
PHP Parser - Processes wiki markup (which uses a more user-friendly syntax, such as "[[link]]" for ma...
Definition Parser.php:70

RequestContext\getMain
static getMain()
Get the RequestContext object associated with the main request.
Definition RequestContext.php:434

Title
Represents a title within MediaWiki.
Definition Title.php:39

Title\getDBkey
getDBkey()
Get the main part with underscores.
Definition Title.php:947

WANObjectCache
Multi-datacenter aware caching interface.
Definition WANObjectCache.php:87

Wikimedia\Rdbms\Database
Relational database abstraction object.
Definition Database.php:48

$res
$res
Definition database.txt:21

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

$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:57

$parser
do that in ParserLimitReportFormat instead $parser
Definition hooks.txt:2603

$status
Status::newGood()` to allow deletion, and then `return false` from the hook function. Ensure you consume the 'ChangeTagAfterDelete' hook to carry out custom deletion actions. $tag:name of the tag $user:user initiating the action & $status:Status object. See above. 'ChangeTagsListActive':Allows you to nominate which of the tags your extension uses are in active use. & $tags:list of all active tags. Append to this array. 'ChangeTagsAfterUpdateTags':Called after tags have been updated with the ChangeTags::updateTags function. Params:$addedTags:tags effectively added in the update $removedTags:tags effectively removed in the update $prevTags:tags that were present prior to the update $rc_id:recentchanges table id $rev_id:revision table id $log_id:logging table id $params:tag params $rc:RecentChange being tagged when the tagging accompanies the action or null $user:User who performed the tagging when the tagging is subsequent to the action or null 'ChangeTagsAllowedAdd':Called when checking if a user can add tags to a change. & $allowedTags:List of all the tags the user is allowed to add. Any tags the user wants to add( $addTags) that are not in this array will cause it to fail. You may add or remove tags to this array as required. $addTags:List of tags user intends to add. $user:User who is adding the tags. 'ChangeUserGroups':Called before user groups are changed. $performer:The User who will perform the change $user:The User whose groups will be changed & $add:The groups that will be added & $remove:The groups that will be removed 'Collation::factory':Called if $wgCategoryCollation is an unknown collation. $collationName:Name of the collation in question & $collationObject:Null. Replace with a subclass of the Collation class that implements the collation given in $collationName. 'ConfirmEmailComplete':Called after a user 's email has been confirmed successfully. $user:user(object) whose email is being confirmed 'ContentAlterParserOutput':Modify parser output for a given content object. Called by Content::getParserOutput after parsing has finished. Can be used for changes that depend on the result of the parsing but have to be done before LinksUpdate is called(such as adding tracking categories based on the rendered HTML). $content:The Content to render $title:Title of the page, as context $parserOutput:ParserOutput to manipulate 'ContentGetParserOutput':Customize parser output for a given content object, called by AbstractContent::getParserOutput. May be used to override the normal model-specific rendering of page content. $content:The Content to render $title:Title of the page, as context $revId:The revision ID, as context $options:ParserOptions for rendering. To avoid confusing the parser cache, the output can only depend on parameters provided to this hook function, not on global state. $generateHtml:boolean, indicating whether full HTML should be generated. If false, generation of HTML may be skipped, but other information should still be present in the ParserOutput object. & $output:ParserOutput, to manipulate or replace 'ContentHandlerDefaultModelFor':Called when the default content model is determined for a given title. May be used to assign a different model for that title. $title:the Title in question & $model:the model name. Use with CONTENT_MODEL_XXX constants. 'ContentHandlerForModelID':Called when a ContentHandler is requested for a given content model name, but no entry for that model exists in $wgContentHandlers. Note:if your extension implements additional models via this hook, please use GetContentModels hook to make them known to core. $modeName:the requested content model name & $handler:set this to a ContentHandler object, if desired. 'ContentModelCanBeUsedOn':Called to determine whether that content model can be used on a given page. This is especially useful to prevent some content models to be used in some special location. $contentModel:ID of the content model in question $title:the Title in question. & $ok:Output parameter, 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. 'ContribsPager::getQueryInfo':Before the contributions query is about to run & $pager:Pager object for contributions & $queryInfo:The query for the contribs Pager 'ContribsPager::reallyDoQuery':Called before really executing the query for My Contributions & $data:an array of results of all contribs queries $pager:The ContribsPager object hooked into $offset:Index offset, inclusive $limit:Exact query limit $descending:Query direction, false for ascending, true for descending 'ContributionsLineEnding':Called before a contributions HTML line is finished $page:SpecialPage object for contributions & $ret:the HTML line $row:the DB row for this line & $classes:the classes to add to the surrounding< li > & $attribs:associative array of other HTML attributes for the< li > element. Currently only data attributes reserved to MediaWiki are allowed(see Sanitizer::isReservedDataAttribute). 'ContributionsToolLinks':Change tool links above Special:Contributions $id:User identifier $title:User page title & $tools:Array of tool links $specialPage:SpecialPage instance for context and services. Can be either SpecialContributions or DeletedContributionsPage. Extensions should type hint against a generic SpecialPage though. 'ConvertContent':Called by AbstractContent::convert when a conversion to another content model is requested. Handler functions that modify $result should generally return false to disable further attempts at conversion. $content:The Content object to be converted. $toModel:The ID of the content model to convert to. $lossy: boolean indicating whether lossy conversion is allowed. & $result:Output parameter, in case the handler function wants to provide a converted Content object. Note that $result->getContentModel() must return $toModel. 'CustomEditor':When invoking the page editor Return true to allow the normal editor to be used, or false if implementing a custom editor, e.g. for a special namespace, etc. $article:Article being edited $user:User performing the edit 'DatabaseOraclePostInit':Called after initialising an Oracle database $db:the DatabaseOracle object 'DeletedContribsPager::reallyDoQuery':Called before really executing the query for Special:DeletedContributions Similar to ContribsPager::reallyDoQuery & $data:an array of results of all contribs queries $pager:The DeletedContribsPager object hooked into $offset:Index offset, inclusive $limit:Exact query limit $descending:Query direction, false for ascending, true for descending 'DeletedContributionsLineEnding':Called before a DeletedContributions HTML line is finished. Similar to ContributionsLineEnding $page:SpecialPage object for DeletedContributions & $ret:the HTML line $row:the DB row for this line & $classes:the classes to add to the surrounding< li > & $attribs:associative array of other HTML attributes for the< li > element. Currently only data attributes reserved to MediaWiki are allowed(see Sanitizer::isReservedDataAttribute). 'DeleteUnknownPreferences':Called by the cleanupPreferences.php maintenance script to build a WHERE clause with which to delete preferences that are not known about. This hook is used by extensions that have dynamically-named preferences that should not be deleted in the usual cleanup process. For example, the Gadgets extension creates preferences prefixed with 'gadget-', and so anything with that prefix is excluded from the deletion. &where:An array that will be passed as the $cond parameter to IDatabase::select() to determine what will be deleted from the user_properties table. $db:The IDatabase object, useful for accessing $db->buildLike() etc. 'DifferenceEngineAfterLoadNewText':called in DifferenceEngine::loadNewText() after the new revision 's content has been loaded into the class member variable $differenceEngine->mNewContent but before returning true from this function. $differenceEngine:DifferenceEngine object 'DifferenceEngineLoadTextAfterNewContentIsLoaded':called in DifferenceEngine::loadText() after the new revision 's content has been loaded into the class member variable $differenceEngine->mNewContent but before checking if the variable 's value is null. This hook can be used to inject content into said class member variable. $differenceEngine:DifferenceEngine object 'DifferenceEngineMarkPatrolledLink':Allows extensions to change the "mark as patrolled" link which is shown both on the diff header as well as on the bottom of a page, usually wrapped in a span element which has class="patrollink". $differenceEngine:DifferenceEngine object & $markAsPatrolledLink:The "mark as patrolled" link HTML(string) $rcid:Recent change ID(rc_id) for this change(int) 'DifferenceEngineMarkPatrolledRCID':Allows extensions to possibly change the rcid parameter. For example the rcid might be set to zero due to the user being the same as the performer of the change but an extension might still want to show it under certain conditions. & $rcid:rc_id(int) of the change or 0 $differenceEngine:DifferenceEngine object $change:RecentChange object $user:User object representing the current user 'DifferenceEngineNewHeader':Allows extensions to change the $newHeader variable, which contains information about the new revision, such as the revision 's author, whether the revision was marked as a minor edit or not, etc. $differenceEngine:DifferenceEngine object & $newHeader:The string containing the various #mw-diff-otitle[1-5] divs, which include things like revision author info, revision comment, RevisionDelete link and more $formattedRevisionTools:Array containing revision tools, some of which may have been injected with the DiffRevisionTools hook $nextlink:String containing the link to the next revision(if any) $status
Definition hooks.txt:1051

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:181

$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:865

$title
namespace and then decline to actually register it file or subcat img or subcat $title
Definition hooks.txt:964

replace
static configuration should be added through ResourceLoaderGetConfigVars instead can be used to get the real title after the basic globals have been set but before ordinary actions take place replace
Definition hooks.txt:2255

false
processing should stop and the error should be shown to the user * false
Definition hooks.txt:187

NS_MEDIAWIKI
const NS_MEDIAWIKI
Definition Defines.php:82

NS_SPECIAL
const NS_SPECIAL
Definition Defines.php:63

Content
Base interface for content objects.
Definition Content.php:34

cache
you have access to all of the normal MediaWiki so you can get a DB use the cache
Definition maintenance.txt:55

$cache
$cache
Definition mcc.php:33

load
MediaWiki has optional support for a high distributed memory object caching system For general information on but for a larger site with heavy load
Definition memcached.txt:6

data
This document describes the state of Postgres support in and is fairly well maintained The main code is very well while extensions are very hit and miss it is probably the most supported database after MySQL Much of the work in making MediaWiki database agnostic came about through the work of creating Postgres but without copying over all the usage comments General notes on the but these can almost always be programmed around *Although Postgres has a true BOOLEAN boolean columns are always mapped to as the code does not always treat the column as a and VARBINARY columns should simply be TEXT The only exception is when VARBINARY is used to store true binary data
Definition postgres.txt:37

DB_REPLICA
const DB_REPLICA
Definition defines.php:25

DB_MASTER
const DB_MASTER
Definition defines.php:29

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

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

$dbr
$dbr
Definition testCompression.php:50