WikiPage.php

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<?php
interface Page {
}

class WikiPage implements Page, IDBAccessObject {
    // Constants for $mDataLoadedFrom and related

    public $mTitle = null;

    public $mDataLoaded = false;         // !< Boolean
    public $mIsRedirect = false;         // !< Boolean
    public $mLatest = false;             // !< Integer (false means "not loaded")
    public $mPreparedEdit = false;

    protected $mId = null;

    protected $mDataLoadedFrom = self::READ_NONE;

    protected $mRedirectTarget = null;

    protected $mLastRevision = null;

    protected $mTimestamp = '';

    protected $mTouched = '19700101000000';

    protected $mCounter = null;

    public function __construct( Title $title ) {
        $this->mTitle = $title;
    }

    public static function factory( Title $title ) {
        $ns = $title->getNamespace();

        if ( $ns == NS_MEDIA ) {
            throw new MWException( "NS_MEDIA is a virtual namespace; use NS_FILE." );
        } elseif ( $ns < 0 ) {
            throw new MWException( "Invalid or virtual namespace $ns given." );
        }

        switch ( $ns ) {
            case NS_FILE:
                $page = new WikiFilePage( $title );
                break;
            case NS_CATEGORY:
                $page = new WikiCategoryPage( $title );
                break;
            default:
                $page = new WikiPage( $title );
        }

        return $page;
    }

    public static function newFromID( $id, $from = 'fromdb' ) {
        $from = self::convertSelectType( $from );
        $db = wfGetDB( $from === self::READ_LATEST ? DB_MASTER : DB_SLAVE );
        $row = $db->selectRow( 'page', self::selectFields(), array( 'page_id' => $id ), __METHOD__ );
        if ( !$row ) {
            return null;
        }
        return self::newFromRow( $row, $from );
    }

    public static function newFromRow( $row, $from = 'fromdb' ) {
        $page = self::factory( Title::newFromRow( $row ) );
        $page->loadFromRow( $row, $from );
        return $page;
    }

    private static function convertSelectType( $type ) {
        switch ( $type ) {
        case 'fromdb':
            return self::READ_NORMAL;
        case 'fromdbmaster':
            return self::READ_LATEST;
        case 'forupdate':
            return self::READ_LOCKING;
        default:
            // It may already be an integer or whatever else
            return $type;
        }
    }

    public function getActionOverrides() {
        $content_handler = $this->getContentHandler();
        return $content_handler->getActionOverrides();
    }

    public function getContentHandler() {
        return ContentHandler::getForModelID( $this->getContentModel() );
    }

    public function getTitle() {
        return $this->mTitle;
    }

    public function clear() {
        $this->mDataLoaded = false;
        $this->mDataLoadedFrom = self::READ_NONE;

        $this->clearCacheFields();
    }

    protected function clearCacheFields() {
        $this->mId = null;
        $this->mCounter = null;
        $this->mRedirectTarget = null; // Title object if set
        $this->mLastRevision = null; // Latest revision
        $this->mTouched = '19700101000000';
        $this->mTimestamp = '';
        $this->mIsRedirect = false;
        $this->mLatest = false;
        // Bug 57026: do not clear mPreparedEdit since prepareTextForEdit() already checks
        // the requested rev ID and immutable content against the cached one.
        // Clearing it can cause extra parses on edit for no reason.
    }

    public function clearPreparedEdit() {
        $this->mPreparedEdit = false;
    }

    public static function selectFields() {
        global $wgContentHandlerUseDB;

        $fields = array(
            'page_id',
            'page_namespace',
            'page_title',
            'page_restrictions',
            'page_counter',
            'page_is_redirect',
            'page_is_new',
            'page_random',
            'page_touched',
            'page_latest',
            'page_len',
        );

        if ( $wgContentHandlerUseDB ) {
            $fields[] = 'page_content_model';
        }

        return $fields;
    }

    protected function pageData( $dbr, $conditions, $options = array() ) {
        $fields = self::selectFields();

        wfRunHooks( 'ArticlePageDataBefore', array( &$this, &$fields ) );

        $row = $dbr->selectRow( 'page', $fields, $conditions, __METHOD__, $options );

        wfRunHooks( 'ArticlePageDataAfter', array( &$this, &$row ) );

        return $row;
    }

    public function pageDataFromTitle( $dbr, $title, $options = array() ) {
        return $this->pageData( $dbr, array(
            'page_namespace' => $title->getNamespace(),
            'page_title' => $title->getDBkey() ), $options );
    }

    public function pageDataFromId( $dbr, $id, $options = array() ) {
        return $this->pageData( $dbr, array( 'page_id' => $id ), $options );
    }

    public function loadPageData( $from = 'fromdb' ) {
        $from = self::convertSelectType( $from );
        if ( is_int( $from ) && $from <= $this->mDataLoadedFrom ) {
            // We already have the data from the correct location, no need to load it twice.
            return;
        }

        if ( $from === self::READ_LOCKING ) {
            $data = $this->pageDataFromTitle( wfGetDB( DB_MASTER ), $this->mTitle, array( 'FOR UPDATE' ) );
        } elseif ( $from === self::READ_LATEST ) {
            $data = $this->pageDataFromTitle( wfGetDB( DB_MASTER ), $this->mTitle );
        } elseif ( $from === self::READ_NORMAL ) {
            $data = $this->pageDataFromTitle( wfGetDB( DB_SLAVE ), $this->mTitle );
            // Use a "last rev inserted" timestamp key to diminish the issue of slave lag.
            // Note that DB also stores the master position in the session and checks it.
            $touched = $this->getCachedLastEditTime();
            if ( $touched ) { // key set
                if ( !$data || $touched > wfTimestamp( TS_MW, $data->page_touched ) ) {
                    $from = self::READ_LATEST;
                    $data = $this->pageDataFromTitle( wfGetDB( DB_MASTER ), $this->mTitle );
                }
            }
        } else {
            // No idea from where the caller got this data, assume slave database.
            $data = $from;
            $from = self::READ_NORMAL;
        }

        $this->loadFromRow( $data, $from );
    }

    public function loadFromRow( $data, $from ) {
        $lc = LinkCache::singleton();
        $lc->clearLink( $this->mTitle );

        if ( $data ) {
            $lc->addGoodLinkObjFromRow( $this->mTitle, $data );

            $this->mTitle->loadFromRow( $data );

            // Old-fashioned restrictions
            $this->mTitle->loadRestrictions( $data->page_restrictions );

            $this->mId = intval( $data->page_id );
            $this->mCounter = intval( $data->page_counter );
            $this->mTouched = wfTimestamp( TS_MW, $data->page_touched );
            $this->mIsRedirect = intval( $data->page_is_redirect );
            $this->mLatest = intval( $data->page_latest );
            // Bug 37225: $latest may no longer match the cached latest Revision object.
            // Double-check the ID of any cached latest Revision object for consistency.
            if ( $this->mLastRevision && $this->mLastRevision->getId() != $this->mLatest ) {
                $this->mLastRevision = null;
                $this->mTimestamp = '';
            }
        } else {
            $lc->addBadLinkObj( $this->mTitle );

            $this->mTitle->loadFromRow( false );

            $this->clearCacheFields();

            $this->mId = 0;
        }

        $this->mDataLoaded = true;
        $this->mDataLoadedFrom = self::convertSelectType( $from );
    }

    public function getId() {
        if ( !$this->mDataLoaded ) {
            $this->loadPageData();
        }
        return $this->mId;
    }

    public function exists() {
        if ( !$this->mDataLoaded ) {
            $this->loadPageData();
        }
        return $this->mId > 0;
    }

    public function hasViewableContent() {
        return $this->exists() || $this->mTitle->isAlwaysKnown();
    }

    public function getCount() {
        if ( !$this->mDataLoaded ) {
            $this->loadPageData();
        }

        return $this->mCounter;
    }

    public function isRedirect() {
        $content = $this->getContent();
        if ( !$content ) {
            return false;
        }

        return $content->isRedirect();
    }

    public function getContentModel() {
        if ( $this->exists() ) {
            // look at the revision's actual content model
            $rev = $this->getRevision();

            if ( $rev !== null ) {
                return $rev->getContentModel();
            } else {
                $title = $this->mTitle->getPrefixedDBkey();
                wfWarn( "Page $title exists but has no (visible) revisions!" );
            }
        }

        // use the default model for this page
        return $this->mTitle->getContentModel();
    }

    public function checkTouched() {
        if ( !$this->mDataLoaded ) {
            $this->loadPageData();
        }
        return !$this->mIsRedirect;
    }

    public function getTouched() {
        if ( !$this->mDataLoaded ) {
            $this->loadPageData();
        }
        return $this->mTouched;
    }

    public function getLatest() {
        if ( !$this->mDataLoaded ) {
            $this->loadPageData();
        }
        return (int)$this->mLatest;
    }

    public function getOldestRevision() {
        wfProfileIn( __METHOD__ );

        // Try using the slave database first, then try the master
        $continue = 2;
        $db = wfGetDB( DB_SLAVE );
        $revSelectFields = Revision::selectFields();

        $row = null;
        while ( $continue ) {
            $row = $db->selectRow(
                array( 'page', 'revision' ),
                $revSelectFields,
                array(
                    'page_namespace' => $this->mTitle->getNamespace(),
                    'page_title' => $this->mTitle->getDBkey(),
                    'rev_page = page_id'
                ),
                __METHOD__,
                array(
                    'ORDER BY' => 'rev_timestamp ASC'
                )
            );

            if ( $row ) {
                $continue = 0;
            } else {
                $db = wfGetDB( DB_MASTER );
                $continue--;
            }
        }

        wfProfileOut( __METHOD__ );
        return $row ? Revision::newFromRow( $row ) : null;
    }

    protected function loadLastEdit() {
        if ( $this->mLastRevision !== null ) {
            return; // already loaded
        }

        $latest = $this->getLatest();
        if ( !$latest ) {
            return; // page doesn't exist or is missing page_latest info
        }

        // Bug 37225: if session S1 loads the page row FOR UPDATE, the result always includes the
        // latest changes committed. This is true even within REPEATABLE-READ transactions, where
        // S1 normally only sees changes committed before the first S1 SELECT. Thus we need S1 to
        // also gets the revision row FOR UPDATE; otherwise, it may not find it since a page row
        // UPDATE and revision row INSERT by S2 may have happened after the first S1 SELECT.
        // http://dev.mysql.com/doc/refman/5.0/en/set-transaction.html#isolevel_repeatable-read.
        $flags = ( $this->mDataLoadedFrom == self::READ_LOCKING ) ? Revision::READ_LOCKING : 0;
        $revision = Revision::newFromPageId( $this->getId(), $latest, $flags );
        if ( $revision ) { // sanity
            $this->setLastEdit( $revision );
        }
    }

    protected function setLastEdit( Revision $revision ) {
        $this->mLastRevision = $revision;
        $this->mTimestamp = $revision->getTimestamp();
    }

    public function getRevision() {
        $this->loadLastEdit();
        if ( $this->mLastRevision ) {
            return $this->mLastRevision;
        }
        return null;
    }

    public function getContent( $audience = Revision::FOR_PUBLIC, User $user = null ) {
        $this->loadLastEdit();
        if ( $this->mLastRevision ) {
            return $this->mLastRevision->getContent( $audience, $user );
        }
        return null;
    }

    public function getText( $audience = Revision::FOR_PUBLIC, User $user = null ) { // @todo deprecated, replace usage!
        ContentHandler::deprecated( __METHOD__, '1.21' );

        $this->loadLastEdit();
        if ( $this->mLastRevision ) {
            return $this->mLastRevision->getText( $audience, $user );
        }
        return false;
    }

    public function getRawText() {
        ContentHandler::deprecated( __METHOD__, '1.21' );

        return $this->getText( Revision::RAW );
    }

    public function getTimestamp() {
        // Check if the field has been filled by WikiPage::setTimestamp()
        if ( !$this->mTimestamp ) {
            $this->loadLastEdit();
        }

        return wfTimestamp( TS_MW, $this->mTimestamp );
    }

    public function setTimestamp( $ts ) {
        $this->mTimestamp = wfTimestamp( TS_MW, $ts );
    }

    public function getUser( $audience = Revision::FOR_PUBLIC, User $user = null ) {
        $this->loadLastEdit();
        if ( $this->mLastRevision ) {
            return $this->mLastRevision->getUser( $audience, $user );
        } else {
            return -1;
        }
    }

    public function getCreator( $audience = Revision::FOR_PUBLIC, User $user = null ) {
        $revision = $this->getOldestRevision();
        if ( $revision ) {
            $userName = $revision->getUserText( $audience, $user );
            return User::newFromName( $userName, false );
        } else {
            return null;
        }
    }

    public function getUserText( $audience = Revision::FOR_PUBLIC, User $user = null ) {
        $this->loadLastEdit();
        if ( $this->mLastRevision ) {
            return $this->mLastRevision->getUserText( $audience, $user );
        } else {
            return '';
        }
    }

    public function getComment( $audience = Revision::FOR_PUBLIC, User $user = null ) {
        $this->loadLastEdit();
        if ( $this->mLastRevision ) {
            return $this->mLastRevision->getComment( $audience, $user );
        } else {
            return '';
        }
    }

    public function getMinorEdit() {
        $this->loadLastEdit();
        if ( $this->mLastRevision ) {
            return $this->mLastRevision->isMinor();
        } else {
            return false;
        }
    }

    protected function getCachedLastEditTime() {
        global $wgMemc;
        $key = wfMemcKey( 'page-lastedit', md5( $this->mTitle->getPrefixedDBkey() ) );
        return $wgMemc->get( $key );
    }

    public function setCachedLastEditTime( $timestamp ) {
        global $wgMemc;
        $key = wfMemcKey( 'page-lastedit', md5( $this->mTitle->getPrefixedDBkey() ) );
        $wgMemc->set( $key, wfTimestamp( TS_MW, $timestamp ), 60 * 15 );
    }

    public function isCountable( $editInfo = false ) {
        global $wgArticleCountMethod;

        if ( !$this->mTitle->isContentPage() ) {
            return false;
        }

        if ( $editInfo ) {
            $content = $editInfo->pstContent;
        } else {
            $content = $this->getContent();
        }

        if ( !$content || $content->isRedirect() ) {
            return false;
        }

        $hasLinks = null;

        if ( $wgArticleCountMethod === 'link' ) {
            // nasty special case to avoid re-parsing to detect links

            if ( $editInfo ) {
                // ParserOutput::getLinks() is a 2D array of page links, so
                // to be really correct we would need to recurse in the array
                // but the main array should only have items in it if there are
                // links.
                $hasLinks = (bool)count( $editInfo->output->getLinks() );
            } else {
                $hasLinks = (bool)wfGetDB( DB_SLAVE )->selectField( 'pagelinks', 1,
                    array( 'pl_from' => $this->getId() ), __METHOD__ );
            }
        }

        return $content->isCountable( $hasLinks );
    }

    public function getRedirectTarget() {
        if ( !$this->mTitle->isRedirect() ) {
            return null;
        }

        if ( $this->mRedirectTarget !== null ) {
            return $this->mRedirectTarget;
        }

        // Query the redirect table
        $dbr = wfGetDB( DB_SLAVE );
        $row = $dbr->selectRow( 'redirect',
            array( 'rd_namespace', 'rd_title', 'rd_fragment', 'rd_interwiki' ),
            array( 'rd_from' => $this->getId() ),
            __METHOD__
        );

        // rd_fragment and rd_interwiki were added later, populate them if empty
        if ( $row && !is_null( $row->rd_fragment ) && !is_null( $row->rd_interwiki ) ) {
            return $this->mRedirectTarget = Title::makeTitle(
                $row->rd_namespace, $row->rd_title,
                $row->rd_fragment, $row->rd_interwiki );
        }

        // This page doesn't have an entry in the redirect table
        return $this->mRedirectTarget = $this->insertRedirect();
    }

    public function insertRedirect() {
        // recurse through to only get the final target
        $content = $this->getContent();
        $retval = $content ? $content->getUltimateRedirectTarget() : null;
        if ( !$retval ) {
            return null;
        }
        $this->insertRedirectEntry( $retval );
        return $retval;
    }

    public function insertRedirectEntry( $rt ) {
        $dbw = wfGetDB( DB_MASTER );
        $dbw->replace( 'redirect', array( 'rd_from' ),
            array(
                'rd_from' => $this->getId(),
                'rd_namespace' => $rt->getNamespace(),
                'rd_title' => $rt->getDBkey(),
                'rd_fragment' => $rt->getFragment(),
                'rd_interwiki' => $rt->getInterwiki(),
            ),
            __METHOD__
        );
    }

    public function followRedirect() {
        return $this->getRedirectURL( $this->getRedirectTarget() );
    }

    public function getRedirectURL( $rt ) {
        if ( !$rt ) {
            return false;
        }

        if ( $rt->isExternal() ) {
            if ( $rt->isLocal() ) {
                // Offsite wikis need an HTTP redirect.
                //
                // This can be hard to reverse and may produce loops,
                // so they may be disabled in the site configuration.
                $source = $this->mTitle->getFullURL( 'redirect=no' );
                return $rt->getFullURL( array( 'rdfrom' => $source ) );
            } else {
                // External pages pages without "local" bit set are not valid
                // redirect targets
                return false;
            }
        }

        if ( $rt->isSpecialPage() ) {
            // Gotta handle redirects to special pages differently:
            // Fill the HTTP response "Location" header and ignore
            // the rest of the page we're on.
            //
            // Some pages are not valid targets
            if ( $rt->isValidRedirectTarget() ) {
                return $rt->getFullURL();
            } else {
                return false;
            }
        }

        return $rt;
    }

    public function getContributors() {
        // @todo FIXME: This is expensive; cache this info somewhere.

        $dbr = wfGetDB( DB_SLAVE );

        if ( $dbr->implicitGroupby() ) {
            $realNameField = 'user_real_name';
        } else {
            $realNameField = 'MIN(user_real_name) AS user_real_name';
        }

        $tables = array( 'revision', 'user' );

        $fields = array(
            'user_id' => 'rev_user',
            'user_name' => 'rev_user_text',
            $realNameField,
            'timestamp' => 'MAX(rev_timestamp)',
        );

        $conds = array( 'rev_page' => $this->getId() );

        // The user who made the top revision gets credited as "this page was last edited by
        // John, based on contributions by Tom, Dick and Harry", so don't include them twice.
        $user = $this->getUser();
        if ( $user ) {
            $conds[] = "rev_user != $user";
        } else {
            $conds[] = "rev_user_text != {$dbr->addQuotes( $this->getUserText() )}";
        }

        $conds[] = "{$dbr->bitAnd( 'rev_deleted', Revision::DELETED_USER )} = 0"; // username hidden?

        $jconds = array(
            'user' => array( 'LEFT JOIN', 'rev_user = user_id' ),
        );

        $options = array(
            'GROUP BY' => array( 'rev_user', 'rev_user_text' ),
            'ORDER BY' => 'timestamp DESC',
        );

        $res = $dbr->select( $tables, $fields, $conds, __METHOD__, $options, $jconds );
        return new UserArrayFromResult( $res );
    }

    public function getLastNAuthors( $num, $revLatest = 0 ) {
        wfProfileIn( __METHOD__ );
        // First try the slave
        // If that doesn't have the latest revision, try the master
        $continue = 2;
        $db = wfGetDB( DB_SLAVE );

        do {
            $res = $db->select( array( 'page', 'revision' ),
                array( 'rev_id', 'rev_user_text' ),
                array(
                    'page_namespace' => $this->mTitle->getNamespace(),
                    'page_title' => $this->mTitle->getDBkey(),
                    'rev_page = page_id'
                ), __METHOD__,
                array(
                    'ORDER BY' => 'rev_timestamp DESC',
                    'LIMIT' => $num
                )
            );

            if ( !$res ) {
                wfProfileOut( __METHOD__ );
                return array();
            }

            $row = $db->fetchObject( $res );

            if ( $continue == 2 && $revLatest && $row->rev_id != $revLatest ) {
                $db = wfGetDB( DB_MASTER );
                $continue--;
            } else {
                $continue = 0;
            }
        } while ( $continue );

        $authors = array( $row->rev_user_text );

        foreach ( $res as $row ) {
            $authors[] = $row->rev_user_text;
        }

        wfProfileOut( __METHOD__ );
        return $authors;
    }

    public function isParserCacheUsed( ParserOptions $parserOptions, $oldid ) {
        global $wgEnableParserCache;

        return $wgEnableParserCache
            && $parserOptions->getStubThreshold() == 0
            && $this->exists()
            && ( $oldid === null || $oldid === 0 || $oldid === $this->getLatest() )
            && $this->getContentHandler()->isParserCacheSupported();
    }

    public function getParserOutput( ParserOptions $parserOptions, $oldid = null ) {
        wfProfileIn( __METHOD__ );

        $useParserCache = $this->isParserCacheUsed( $parserOptions, $oldid );
        wfDebug( __METHOD__ . ': using parser cache: ' . ( $useParserCache ? 'yes' : 'no' ) . "\n" );
        if ( $parserOptions->getStubThreshold() ) {
            wfIncrStats( 'pcache_miss_stub' );
        }

        if ( $useParserCache ) {
            $parserOutput = ParserCache::singleton()->get( $this, $parserOptions );
            if ( $parserOutput !== false ) {
                wfProfileOut( __METHOD__ );
                return $parserOutput;
            }
        }

        if ( $oldid === null || $oldid === 0 ) {
            $oldid = $this->getLatest();
        }

        $pool = new PoolWorkArticleView( $this, $parserOptions, $oldid, $useParserCache );
        $pool->execute();

        wfProfileOut( __METHOD__ );

        return $pool->getParserOutput();
    }

    public function doViewUpdates( User $user ) {
        global $wgDisableCounters;
        if ( wfReadOnly() ) {
            return;
        }

        // Don't update page view counters on views from bot users (bug 14044)
        if ( !$wgDisableCounters && !$user->isAllowed( 'bot' ) && $this->exists() ) {
            DeferredUpdates::addUpdate( new ViewCountUpdate( $this->getId() ) );
            DeferredUpdates::addUpdate( new SiteStatsUpdate( 1, 0, 0 ) );
        }

        // Update newtalk / watchlist notification status
        $user->clearNotification( $this->mTitle );
    }

    public function doPurge() {
        global $wgUseSquid;

        if ( !wfRunHooks( 'ArticlePurge', array( &$this ) ) ) {
            return false;
        }

        // Invalidate the cache
        $this->mTitle->invalidateCache();

        if ( $wgUseSquid ) {
            // Commit the transaction before the purge is sent
            $dbw = wfGetDB( DB_MASTER );
            $dbw->commit( __METHOD__ );

            // Send purge
            $update = SquidUpdate::newSimplePurge( $this->mTitle );
            $update->doUpdate();
        }

        if ( $this->mTitle->getNamespace() == NS_MEDIAWIKI ) {
            // @todo move this logic to MessageCache

            if ( $this->exists() ) {
                // NOTE: use transclusion text for messages.
                //       This is consistent with  MessageCache::getMsgFromNamespace()

                $content = $this->getContent();
                $text = $content === null ? null : $content->getWikitextForTransclusion();

                if ( $text === null ) {
                    $text = false;
                }
            } else {
                $text = false;
            }

            MessageCache::singleton()->replace( $this->mTitle->getDBkey(), $text );
        }
        return true;
    }

    public function insertOn( $dbw ) {
        wfProfileIn( __METHOD__ );

        $page_id = $dbw->nextSequenceValue( 'page_page_id_seq' );
        $dbw->insert( 'page', array(
            'page_id'           => $page_id,
            'page_namespace'    => $this->mTitle->getNamespace(),
            'page_title'        => $this->mTitle->getDBkey(),
            'page_counter'      => 0,
            'page_restrictions' => '',
            'page_is_redirect'  => 0, // Will set this shortly...
            'page_is_new'       => 1,
            'page_random'       => wfRandom(),
            'page_touched'      => $dbw->timestamp(),
            'page_latest'       => 0, // Fill this in shortly...
            'page_len'          => 0, // Fill this in shortly...
        ), __METHOD__, 'IGNORE' );

        $affected = $dbw->affectedRows();

        if ( $affected ) {
            $newid = $dbw->insertId();
            $this->mId = $newid;
            $this->mTitle->resetArticleID( $newid );
        }
        wfProfileOut( __METHOD__ );

        return $affected ? $newid : false;
    }

    public function updateRevisionOn( $dbw, $revision, $lastRevision = null, $lastRevIsRedirect = null ) {
        global $wgContentHandlerUseDB;

        wfProfileIn( __METHOD__ );

        $content = $revision->getContent();
        $len = $content ? $content->getSize() : 0;
        $rt = $content ? $content->getUltimateRedirectTarget() : null;

        $conditions = array( 'page_id' => $this->getId() );

        if ( !is_null( $lastRevision ) ) {
            // An extra check against threads stepping on each other
            $conditions['page_latest'] = $lastRevision;
        }

        $now = wfTimestampNow();
        $row = array( /* SET */
            'page_latest'      => $revision->getId(),
            'page_touched'     => $dbw->timestamp( $now ),
            'page_is_new'      => ( $lastRevision === 0 ) ? 1 : 0,
            'page_is_redirect' => $rt !== null ? 1 : 0,
            'page_len'         => $len,
        );

        if ( $wgContentHandlerUseDB ) {
            $row['page_content_model'] = $revision->getContentModel();
        }

        $dbw->update( 'page',
            $row,
            $conditions,
            __METHOD__ );

        $result = $dbw->affectedRows() > 0;
        if ( $result ) {
            $this->updateRedirectOn( $dbw, $rt, $lastRevIsRedirect );
            $this->setLastEdit( $revision );
            $this->setCachedLastEditTime( $now );
            $this->mLatest = $revision->getId();
            $this->mIsRedirect = (bool)$rt;
            // Update the LinkCache.
            LinkCache::singleton()->addGoodLinkObj( $this->getId(), $this->mTitle, $len, $this->mIsRedirect,
                                                    $this->mLatest, $revision->getContentModel() );
        }

        wfProfileOut( __METHOD__ );
        return $result;
    }

    public function updateRedirectOn( $dbw, $redirectTitle, $lastRevIsRedirect = null ) {
        // Always update redirects (target link might have changed)
        // Update/Insert if we don't know if the last revision was a redirect or not
        // Delete if changing from redirect to non-redirect
        $isRedirect = !is_null( $redirectTitle );

        if ( !$isRedirect && $lastRevIsRedirect === false ) {
            return true;
        }

        wfProfileIn( __METHOD__ );
        if ( $isRedirect ) {
            $this->insertRedirectEntry( $redirectTitle );
        } else {
            // This is not a redirect, remove row from redirect table
            $where = array( 'rd_from' => $this->getId() );
            $dbw->delete( 'redirect', $where, __METHOD__ );
        }

        if ( $this->getTitle()->getNamespace() == NS_FILE ) {
            RepoGroup::singleton()->getLocalRepo()->invalidateImageRedirect( $this->getTitle() );
        }
        wfProfileOut( __METHOD__ );

        return ( $dbw->affectedRows() != 0 );
    }

    public function updateIfNewerOn( $dbw, $revision ) {
        wfProfileIn( __METHOD__ );

        $row = $dbw->selectRow(
            array( 'revision', 'page' ),
            array( 'rev_id', 'rev_timestamp', 'page_is_redirect' ),
            array(
                'page_id' => $this->getId(),
                'page_latest=rev_id' ),
            __METHOD__ );

        if ( $row ) {
            if ( wfTimestamp( TS_MW, $row->rev_timestamp ) >= $revision->getTimestamp() ) {
                wfProfileOut( __METHOD__ );
                return false;
            }
            $prev = $row->rev_id;
            $lastRevIsRedirect = (bool)$row->page_is_redirect;
        } else {
            // No or missing previous revision; mark the page as new
            $prev = 0;
            $lastRevIsRedirect = null;
        }

        $ret = $this->updateRevisionOn( $dbw, $revision, $prev, $lastRevIsRedirect );

        wfProfileOut( __METHOD__ );
        return $ret;
    }

    public function getUndoContent( Revision $undo, Revision $undoafter = null ) {
        $handler = $undo->getContentHandler();
        return $handler->getUndoContent( $this->getRevision(), $undo, $undoafter );
    }

    public function getUndoText( Revision $undo, Revision $undoafter = null ) {
        ContentHandler::deprecated( __METHOD__, '1.21' );

        $this->loadLastEdit();

        if ( $this->mLastRevision ) {
            if ( is_null( $undoafter ) ) {
                $undoafter = $undo->getPrevious();
            }

            $handler = $this->getContentHandler();
            $undone = $handler->getUndoContent( $this->mLastRevision, $undo, $undoafter );

            if ( !$undone ) {
                return false;
            } else {
                return ContentHandler::getContentText( $undone );
            }
        }

        return false;
    }

    public function replaceSection( $section, $text, $sectionTitle = '', $edittime = null ) {
        ContentHandler::deprecated( __METHOD__, '1.21' );

        if ( strval( $section ) == '' ) { //NOTE: keep condition in sync with condition in replaceSectionContent!
            // Whole-page edit; let the whole text through
            return $text;
        }

        if ( !$this->supportsSections() ) {
            throw new MWException( "sections not supported for content model " . $this->getContentHandler()->getModelID() );
        }

        // could even make section title, but that's not required.
        $sectionContent = ContentHandler::makeContent( $text, $this->getTitle() );

        $newContent = $this->replaceSectionContent( $section, $sectionContent, $sectionTitle, $edittime );

        return ContentHandler::getContentText( $newContent );
    }

    public function supportsSections() {
        return $this->getContentHandler()->supportsSections();
    }

    public function replaceSectionContent( $section, Content $sectionContent, $sectionTitle = '', $edittime = null ) {
        wfProfileIn( __METHOD__ );

        if ( strval( $section ) == '' ) {
            // Whole-page edit; let the whole text through
            $newContent = $sectionContent;
        } else {
            if ( !$this->supportsSections() ) {
                wfProfileOut( __METHOD__ );
                throw new MWException( "sections not supported for content model " . $this->getContentHandler()->getModelID() );
            }

            // Bug 30711: always use current version when adding a new section
            if ( is_null( $edittime ) || $section == 'new' ) {
                $oldContent = $this->getContent();
            } else {
                $dbw = wfGetDB( DB_MASTER );
                $rev = Revision::loadFromTimestamp( $dbw, $this->mTitle, $edittime );

                if ( !$rev ) {
                    wfDebug( "WikiPage::replaceSection asked for bogus section (page: " .
                        $this->getId() . "; section: $section; edittime: $edittime)\n" );
                    wfProfileOut( __METHOD__ );
                    return null;
                }

                $oldContent = $rev->getContent();
            }

            if ( ! $oldContent ) {
                wfDebug( __METHOD__ . ": no page text\n" );
                wfProfileOut( __METHOD__ );
                return null;
            }

            // FIXME: $oldContent might be null?
            $newContent = $oldContent->replaceSection( $section, $sectionContent, $sectionTitle );
        }

        wfProfileOut( __METHOD__ );
        return $newContent;
    }

    function checkFlags( $flags ) {
        if ( !( $flags & EDIT_NEW ) && !( $flags & EDIT_UPDATE ) ) {
            if ( $this->exists() ) {
                $flags |= EDIT_UPDATE;
            } else {
                $flags |= EDIT_NEW;
            }
        }

        return $flags;
    }

    public function doEdit( $text, $summary, $flags = 0, $baseRevId = false, $user = null ) {
        ContentHandler::deprecated( __METHOD__, '1.21' );

        $content = ContentHandler::makeContent( $text, $this->getTitle() );

        return $this->doEditContent( $content, $summary, $flags, $baseRevId, $user );
    }

    public function doEditContent( Content $content, $summary, $flags = 0, $baseRevId = false,
                                   User $user = null, $serialisation_format = null ) {
        global $wgUser, $wgUseAutomaticEditSummaries, $wgUseRCPatrol, $wgUseNPPatrol;

        // Low-level sanity check
        if ( $this->mTitle->getText() === '' ) {
            throw new MWException( 'Something is trying to edit an article with an empty title' );
        }

        wfProfileIn( __METHOD__ );

        if ( !$content->getContentHandler()->canBeUsedOn( $this->getTitle() ) ) {
            wfProfileOut( __METHOD__ );
            return Status::newFatal( 'content-not-allowed-here',
                ContentHandler::getLocalizedName( $content->getModel() ),
                $this->getTitle()->getPrefixedText() );
        }

        $user = is_null( $user ) ? $wgUser : $user;
        $status = Status::newGood( array() );

        // Load the data from the master database if needed.
        // The caller may already loaded it from the master or even loaded it using
        // SELECT FOR UPDATE, so do not override that using clear().
        $this->loadPageData( 'fromdbmaster' );

        $flags = $this->checkFlags( $flags );

        // handle hook
        $hook_args = array( &$this, &$user, &$content, &$summary,
                            $flags & EDIT_MINOR, null, null, &$flags, &$status );

        if ( !wfRunHooks( 'PageContentSave', $hook_args )
            || !ContentHandler::runLegacyHooks( 'ArticleSave', $hook_args ) ) {

            wfDebug( __METHOD__ . ": ArticleSave or ArticleSaveContent hook aborted save!\n" );

            if ( $status->isOK() ) {
                $status->fatal( 'edit-hook-aborted' );
            }

            wfProfileOut( __METHOD__ );
            return $status;
        }

        // Silently ignore EDIT_MINOR if not allowed
        $isminor = ( $flags & EDIT_MINOR ) && $user->isAllowed( 'minoredit' );
        $bot = $flags & EDIT_FORCE_BOT;

        $old_content = $this->getContent( Revision::RAW ); // current revision's content

        $oldsize = $old_content ? $old_content->getSize() : 0;
        $oldid = $this->getLatest();
        $oldIsRedirect = $this->isRedirect();
        $oldcountable = $this->isCountable();

        $handler = $content->getContentHandler();

        // Provide autosummaries if one is not provided and autosummaries are enabled.
        if ( $wgUseAutomaticEditSummaries && $flags & EDIT_AUTOSUMMARY && $summary == '' ) {
            if ( !$old_content ) {
                $old_content = null;
            }
            $summary = $handler->getAutosummary( $old_content, $content, $flags );
        }

        $editInfo = $this->prepareContentForEdit( $content, null, $user, $serialisation_format );
        $serialized = $editInfo->pst;

        $content = $editInfo->pstContent;
        $newsize = $content->getSize();

        $dbw = wfGetDB( DB_MASTER );
        $now = wfTimestampNow();
        $this->mTimestamp = $now;

        if ( $flags & EDIT_UPDATE ) {
            // Update article, but only if changed.
            $status->value['new'] = false;

            if ( !$oldid ) {
                // Article gone missing
                wfDebug( __METHOD__ . ": EDIT_UPDATE specified but article doesn't exist\n" );
                $status->fatal( 'edit-gone-missing' );

                wfProfileOut( __METHOD__ );
                return $status;
            } elseif ( !$old_content ) {
                // Sanity check for bug 37225
                wfProfileOut( __METHOD__ );
                throw new MWException( "Could not find text for current revision {$oldid}." );
            }

            $revision = new Revision( array(
                'page'       => $this->getId(),
                'title'      => $this->getTitle(), // for determining the default content model
                'comment'    => $summary,
                'minor_edit' => $isminor,
                'text'       => $serialized,
                'len'        => $newsize,
                'parent_id'  => $oldid,
                'user'       => $user->getId(),
                'user_text'  => $user->getName(),
                'timestamp'  => $now,
                'content_model' => $content->getModel(),
                'content_format' => $serialisation_format,
            ) ); // XXX: pass content object?!

            $changed = !$content->equals( $old_content );

            if ( $changed ) {
                if ( !$content->isValid() ) {
                    wfProfileOut( __METHOD__ );
                    throw new MWException( "New content failed validity check!" );
                }

                $dbw->begin( __METHOD__ );

                $prepStatus = $content->prepareSave( $this, $flags, $baseRevId, $user );
                $status->merge( $prepStatus );

                if ( !$status->isOK() ) {
                    $dbw->rollback( __METHOD__ );

                    wfProfileOut( __METHOD__ );
                    return $status;
                }

                $revisionId = $revision->insertOn( $dbw );

                // Update page
                //
                // Note that we use $this->mLatest instead of fetching a value from the master DB
                // during the course of this function. This makes sure that EditPage can detect
                // edit conflicts reliably, either by $ok here, or by $article->getTimestamp()
                // before this function is called. A previous function used a separate query, this
                // creates a window where concurrent edits can cause an ignored edit conflict.
                $ok = $this->updateRevisionOn( $dbw, $revision, $oldid, $oldIsRedirect );

                if ( !$ok ) {
                    // Belated edit conflict! Run away!!
                    $status->fatal( 'edit-conflict' );

                    $dbw->rollback( __METHOD__ );

                    wfProfileOut( __METHOD__ );
                    return $status;
                }

                wfRunHooks( 'NewRevisionFromEditComplete', array( $this, $revision, $baseRevId, $user ) );
                // Update recentchanges
                if ( !( $flags & EDIT_SUPPRESS_RC ) ) {
                    // Mark as patrolled if the user can do so
                    $patrolled = $wgUseRCPatrol && !count(
                        $this->mTitle->getUserPermissionsErrors( 'autopatrol', $user ) );
                    // Add RC row to the DB
                    $rc = RecentChange::notifyEdit( $now, $this->mTitle, $isminor, $user, $summary,
                        $oldid, $this->getTimestamp(), $bot, '', $oldsize, $newsize,
                        $revisionId, $patrolled
                    );

                    // Log auto-patrolled edits
                    if ( $patrolled ) {
                        PatrolLog::record( $rc, true, $user );
                    }
                }
                $user->incEditCount();
                $dbw->commit( __METHOD__ );
            } else {
                // Bug 32948: revision ID must be set to page {{REVISIONID}} and
                // related variables correctly
                $revision->setId( $this->getLatest() );
            }

            // Update links tables, site stats, etc.
            $this->doEditUpdates(
                $revision,
                $user,
                array(
                    'changed' => $changed,
                    'oldcountable' => $oldcountable
                )
            );

            if ( !$changed ) {
                $status->warning( 'edit-no-change' );
                $revision = null;
                // Update page_touched, this is usually implicit in the page update
                // Other cache updates are done in onArticleEdit()
                $this->mTitle->invalidateCache();
            }
        } else {
            // Create new article
            $status->value['new'] = true;

            $dbw->begin( __METHOD__ );

            $prepStatus = $content->prepareSave( $this, $flags, $baseRevId, $user );
            $status->merge( $prepStatus );

            if ( !$status->isOK() ) {
                $dbw->rollback( __METHOD__ );

                wfProfileOut( __METHOD__ );
                return $status;
            }

            $status->merge( $prepStatus );

            // Add the page record; stake our claim on this title!
            // This will return false if the article already exists
            $newid = $this->insertOn( $dbw );

            if ( $newid === false ) {
                $dbw->rollback( __METHOD__ );
                $status->fatal( 'edit-already-exists' );

                wfProfileOut( __METHOD__ );
                return $status;
            }

            // Save the revision text...
            $revision = new Revision( array(
                'page'       => $newid,
                'title'      => $this->getTitle(), // for determining the default content model
                'comment'    => $summary,
                'minor_edit' => $isminor,
                'text'       => $serialized,
                'len'        => $newsize,
                'user'       => $user->getId(),
                'user_text'  => $user->getName(),
                'timestamp'  => $now,
                'content_model' => $content->getModel(),
                'content_format' => $serialisation_format,
            ) );
            $revisionId = $revision->insertOn( $dbw );

            // Bug 37225: use accessor to get the text as Revision may trim it
            $content = $revision->getContent(); // sanity; get normalized version

            if ( $content ) {
                $newsize = $content->getSize();
            }

            // Update the page record with revision data
            $this->updateRevisionOn( $dbw, $revision, 0 );

            wfRunHooks( 'NewRevisionFromEditComplete', array( $this, $revision, false, $user ) );

            // Update recentchanges
            if ( !( $flags & EDIT_SUPPRESS_RC ) ) {
                // Mark as patrolled if the user can do so
                $patrolled = ( $wgUseRCPatrol || $wgUseNPPatrol ) && !count(
                    $this->mTitle->getUserPermissionsErrors( 'autopatrol', $user ) );
                // Add RC row to the DB
                $rc = RecentChange::notifyNew( $now, $this->mTitle, $isminor, $user, $summary, $bot,
                    '', $newsize, $revisionId, $patrolled );

                // Log auto-patrolled edits
                if ( $patrolled ) {
                    PatrolLog::record( $rc, true, $user );
                }
            }
            $user->incEditCount();
            $dbw->commit( __METHOD__ );

            // Update links, etc.
            $this->doEditUpdates( $revision, $user, array( 'created' => true ) );

            $hook_args = array( &$this, &$user, $content, $summary,
                                $flags & EDIT_MINOR, null, null, &$flags, $revision );

            ContentHandler::runLegacyHooks( 'ArticleInsertComplete', $hook_args );
            wfRunHooks( 'PageContentInsertComplete', $hook_args );
        }

        // Do updates right now unless deferral was requested
        if ( !( $flags & EDIT_DEFER_UPDATES ) ) {
            DeferredUpdates::doUpdates();
        }

        // Return the new revision (or null) to the caller
        $status->value['revision'] = $revision;

        $hook_args = array( &$this, &$user, $content, $summary,
                            $flags & EDIT_MINOR, null, null, &$flags, $revision, &$status, $baseRevId );

        ContentHandler::runLegacyHooks( 'ArticleSaveComplete', $hook_args );
        wfRunHooks( 'PageContentSaveComplete', $hook_args );

        // Promote user to any groups they meet the criteria for
        $user->addAutopromoteOnceGroups( 'onEdit' );

        wfProfileOut( __METHOD__ );
        return $status;
    }

    public function makeParserOptions( $context ) {
        $options = $this->getContentHandler()->makeParserOptions( $context );

        if ( $this->getTitle()->isConversionTable() ) {
            // @todo ConversionTable should become a separate content model, so we don't need special cases like this one.
            $options->disableContentConversion();
        }

        return $options;
    }

    public function prepareTextForEdit( $text, $revid = null, User $user = null ) {
        ContentHandler::deprecated( __METHOD__, '1.21' );
        $content = ContentHandler::makeContent( $text, $this->getTitle() );
        return $this->prepareContentForEdit( $content, $revid, $user );
    }

    public function prepareContentForEdit( Content $content, $revid = null, User $user = null,
        $serialization_format = null
    ) {
        global $wgContLang, $wgUser;
        $user = is_null( $user ) ? $wgUser : $user;
        //XXX: check $user->getId() here???

        if ( $this->mPreparedEdit
            && $this->mPreparedEdit->newContent
            && $this->mPreparedEdit->newContent->equals( $content )
            && $this->mPreparedEdit->revid == $revid
            && $this->mPreparedEdit->format == $serialization_format
            // XXX: also check $user here?
        ) {
            // Already prepared
            return $this->mPreparedEdit;
        }

        $popts = ParserOptions::newFromUserAndLang( $user, $wgContLang );
        wfRunHooks( 'ArticlePrepareTextForEdit', array( $this, $popts ) );

        $edit = (object)array();
        $edit->revid = $revid;

        $edit->pstContent = $content ? $content->preSaveTransform( $this->mTitle, $user, $popts ) : null;

        $edit->format = $serialization_format;
        $edit->popts = $this->makeParserOptions( 'canonical' );
        $edit->output = $edit->pstContent ? $edit->pstContent->getParserOutput( $this->mTitle, $revid, $edit->popts ) : null;

        $edit->newContent = $content;
        $edit->oldContent = $this->getContent( Revision::RAW );

        // NOTE: B/C for hooks! don't use these fields!
        $edit->newText = $edit->newContent ? ContentHandler::getContentText( $edit->newContent ) : '';
        $edit->oldText = $edit->oldContent ? ContentHandler::getContentText( $edit->oldContent ) : '';
        $edit->pst = $edit->pstContent ? $edit->pstContent->serialize( $serialization_format ) : '';

        $this->mPreparedEdit = $edit;
        return $edit;
    }

    public function doEditUpdates( Revision $revision, User $user, array $options = array() ) {
        global $wgEnableParserCache;

        wfProfileIn( __METHOD__ );

        $options += array( 'changed' => true, 'created' => false, 'oldcountable' => null );
        $content = $revision->getContent();

        // Parse the text
        // Be careful not to do pre-save transform twice: $text is usually
        // already pre-save transformed once.
        if ( !$this->mPreparedEdit || $this->mPreparedEdit->output->getFlag( 'vary-revision' ) ) {
            wfDebug( __METHOD__ . ": No prepared edit or vary-revision is set...\n" );
            $editInfo = $this->prepareContentForEdit( $content, $revision->getId(), $user );
        } else {
            wfDebug( __METHOD__ . ": No vary-revision, using prepared edit...\n" );
            $editInfo = $this->mPreparedEdit;
        }

        // Save it to the parser cache
        if ( $wgEnableParserCache ) {
            $parserCache = ParserCache::singleton();
            $parserCache->save( $editInfo->output, $this, $editInfo->popts );
        }

        // Update the links tables and other secondary data
        if ( $content ) {
            $recursive = $options['changed']; // bug 50785
            $updates = $content->getSecondaryDataUpdates(
                $this->getTitle(), null, $recursive, $editInfo->output );
            DataUpdate::runUpdates( $updates );
        }

        wfRunHooks( 'ArticleEditUpdates', array( &$this, &$editInfo, $options['changed'] ) );

        if ( wfRunHooks( 'ArticleEditUpdatesDeleteFromRecentchanges', array( &$this ) ) ) {
            if ( 0 == mt_rand( 0, 99 ) ) {
                // Flush old entries from the `recentchanges` table; we do this on
                // random requests so as to avoid an increase in writes for no good reason
                RecentChange::purgeExpiredChanges();
            }
        }

        if ( !$this->exists() ) {
            wfProfileOut( __METHOD__ );
            return;
        }

        $id = $this->getId();
        $title = $this->mTitle->getPrefixedDBkey();
        $shortTitle = $this->mTitle->getDBkey();

        if ( !$options['changed'] ) {
            $good = 0;
            $total = 0;
        } elseif ( $options['created'] ) {
            $good = (int)$this->isCountable( $editInfo );
            $total = 1;
        } elseif ( $options['oldcountable'] !== null ) {
            $good = (int)$this->isCountable( $editInfo ) - (int)$options['oldcountable'];
            $total = 0;
        } else {
            $good = 0;
            $total = 0;
        }

        DeferredUpdates::addUpdate( new SiteStatsUpdate( 0, 1, $good, $total ) );
        DeferredUpdates::addUpdate( new SearchUpdate( $id, $title, $content ) );

        // If this is another user's talk page, update newtalk.
        // Don't do this if $options['changed'] = false (null-edits) nor if
        // it's a minor edit and the user doesn't want notifications for those.
        if ( $options['changed']
            && $this->mTitle->getNamespace() == NS_USER_TALK
            && $shortTitle != $user->getTitleKey()
            && !( $revision->isMinor() && $user->isAllowed( 'nominornewtalk' ) )
        ) {
            $recipient = User::newFromName( $shortTitle, false );
            if ( !$recipient ) {
                wfDebug( __METHOD__ . ": invalid username\n" );
            } else {
                // Allow extensions to prevent user notification when a new message is added to their talk page
                if ( wfRunHooks( 'ArticleEditUpdateNewTalk', array( &$this, $recipient ) ) ) {
                    if ( User::isIP( $shortTitle ) ) {
                        // An anonymous user
                        $recipient->setNewtalk( true, $revision );
                    } elseif ( $recipient->isLoggedIn() ) {
                        $recipient->setNewtalk( true, $revision );
                    } else {
                        wfDebug( __METHOD__ . ": don't need to notify a nonexistent user\n" );
                    }
                }
            }
        }

        if ( $this->mTitle->getNamespace() == NS_MEDIAWIKI ) {
            // XXX: could skip pseudo-messages like js/css here, based on content model.
            $msgtext = $content ? $content->getWikitextForTransclusion() : null;
            if ( $msgtext === false || $msgtext === null ) {
                $msgtext = '';
            }

            MessageCache::singleton()->replace( $shortTitle, $msgtext );
        }

        if ( $options['created'] ) {
            self::onArticleCreate( $this->mTitle );
        } else {
            self::onArticleEdit( $this->mTitle );
        }

        wfProfileOut( __METHOD__ );
    }

    public function doQuickEdit( $text, User $user, $comment = '', $minor = 0 ) {
        ContentHandler::deprecated( __METHOD__, "1.21" );

        $content = ContentHandler::makeContent( $text, $this->getTitle() );
        $this->doQuickEditContent( $content, $user, $comment, $minor );
    }

    public function doQuickEditContent( Content $content, User $user, $comment = '', $minor = false,
        $serialisation_format = null
    ) {
        wfProfileIn( __METHOD__ );

        $serialized = $content->serialize( $serialisation_format );

        $dbw = wfGetDB( DB_MASTER );
        $revision = new Revision( array(
            'title'      => $this->getTitle(), // for determining the default content model
            'page'       => $this->getId(),
            'text'       => $serialized,
            'length'     => $content->getSize(),
            'comment'    => $comment,
            'minor_edit' => $minor ? 1 : 0,
        ) ); // XXX: set the content object?
        $revision->insertOn( $dbw );
        $this->updateRevisionOn( $dbw, $revision );

        wfRunHooks( 'NewRevisionFromEditComplete', array( $this, $revision, false, $user ) );

        wfProfileOut( __METHOD__ );
    }

    public function doUpdateRestrictions( array $limit, array $expiry, &$cascade, $reason, User $user ) {
        global $wgCascadingRestrictionLevels;

        if ( wfReadOnly() ) {
            return Status::newFatal( 'readonlytext', wfReadOnlyReason() );
        }

        $restrictionTypes = $this->mTitle->getRestrictionTypes();

        $id = $this->getId();

        if ( !$cascade ) {
            $cascade = false;
        }

        // Take this opportunity to purge out expired restrictions
        Title::purgeExpiredRestrictions();

        // @todo FIXME: Same limitations as described in ProtectionForm.php (line 37);
        // we expect a single selection, but the schema allows otherwise.
        $isProtected = false;
        $protect = false;
        $changed = false;

        $dbw = wfGetDB( DB_MASTER );

        foreach ( $restrictionTypes as $action ) {
            if ( !isset( $expiry[$action] ) ) {
                $expiry[$action] = $dbw->getInfinity();
            }
            if ( !isset( $limit[$action] ) ) {
                $limit[$action] = '';
            } elseif ( $limit[$action] != '' ) {
                $protect = true;
            }

            // Get current restrictions on $action
            $current = implode( '', $this->mTitle->getRestrictions( $action ) );
            if ( $current != '' ) {
                $isProtected = true;
            }

            if ( $limit[$action] != $current ) {
                $changed = true;
            } elseif ( $limit[$action] != '' ) {
                // Only check expiry change if the action is actually being
                // protected, since expiry does nothing on an not-protected
                // action.
                if ( $this->mTitle->getRestrictionExpiry( $action ) != $expiry[$action] ) {
                    $changed = true;
                }
            }
        }

        if ( !$changed && $protect && $this->mTitle->areRestrictionsCascading() != $cascade ) {
            $changed = true;
        }

        // If nothing has changed, do nothing
        if ( !$changed ) {
            return Status::newGood();
        }

        if ( !$protect ) { // No protection at all means unprotection
            $revCommentMsg = 'unprotectedarticle';
            $logAction = 'unprotect';
        } elseif ( $isProtected ) {
            $revCommentMsg = 'modifiedarticleprotection';
            $logAction = 'modify';
        } else {
            $revCommentMsg = 'protectedarticle';
            $logAction = 'protect';
        }

        if ( $id ) { // Protection of existing page
            if ( !wfRunHooks( 'ArticleProtect', array( &$this, &$user, $limit, $reason ) ) ) {
                return Status::newGood();
            }

            // Only certain restrictions can cascade...
            $editrestriction = isset( $limit['edit'] ) ? array( $limit['edit'] ) : $this->mTitle->getRestrictions( 'edit' );
            foreach ( array_keys( $editrestriction, 'sysop' ) as $key ) {
                $editrestriction[$key] = 'editprotected'; // backwards compatibility
            }
            foreach ( array_keys( $editrestriction, 'autoconfirmed' ) as $key ) {
                $editrestriction[$key] = 'editsemiprotected'; // backwards compatibility
            }

            $cascadingRestrictionLevels = $wgCascadingRestrictionLevels;
            foreach ( array_keys( $cascadingRestrictionLevels, 'sysop' ) as $key ) {
                $cascadingRestrictionLevels[$key] = 'editprotected'; // backwards compatibility
            }
            foreach ( array_keys( $cascadingRestrictionLevels, 'autoconfirmed' ) as $key ) {
                $cascadingRestrictionLevels[$key] = 'editsemiprotected'; // backwards compatibility
            }

            // The schema allows multiple restrictions
            if ( !array_intersect( $editrestriction, $cascadingRestrictionLevels ) ) {
                $cascade = false;
            }

            // insert null revision to identify the page protection change as edit summary
            $latest = $this->getLatest();
            $nullRevision = $this->insertProtectNullRevision( $revCommentMsg, $limit, $expiry, $cascade, $reason );
            if ( $nullRevision === null ) {
                return Status::newFatal( 'no-null-revision', $this->mTitle->getPrefixedText() );
            }

            // Update restrictions table
            foreach ( $limit as $action => $restrictions ) {
                if ( $restrictions != '' ) {
                    $dbw->replace( 'page_restrictions', array( array( 'pr_page', 'pr_type' ) ),
                        array( 'pr_page' => $id,
                            'pr_type' => $action,
                            'pr_level' => $restrictions,
                            'pr_cascade' => ( $cascade && $action == 'edit' ) ? 1 : 0,
                            'pr_expiry' => $dbw->encodeExpiry( $expiry[$action] )
                        ),
                        __METHOD__
                    );
                } else {
                    $dbw->delete( 'page_restrictions', array( 'pr_page' => $id,
                        'pr_type' => $action ), __METHOD__ );
                }
            }

            // Clear out legacy restriction fields
            $dbw->update(
                'page',
                array( 'page_restrictions' => '' ),
                array( 'page_id' => $id ),
                __METHOD__
            );

            wfRunHooks( 'NewRevisionFromEditComplete', array( $this, $nullRevision, $latest, $user ) );
            wfRunHooks( 'ArticleProtectComplete', array( &$this, &$user, $limit, $reason ) );
        } else { // Protection of non-existing page (also known as "title protection")
            // Cascade protection is meaningless in this case
            $cascade = false;

            if ( $limit['create'] != '' ) {
                $dbw->replace( 'protected_titles',
                    array( array( 'pt_namespace', 'pt_title' ) ),
                    array(
                        'pt_namespace' => $this->mTitle->getNamespace(),
                        'pt_title' => $this->mTitle->getDBkey(),
                        'pt_create_perm' => $limit['create'],
                        'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
                        'pt_expiry' => $dbw->encodeExpiry( $expiry['create'] ),
                        'pt_user' => $user->getId(),
                        'pt_reason' => $reason,
                    ), __METHOD__
                );
            } else {
                $dbw->delete( 'protected_titles',
                    array(
                        'pt_namespace' => $this->mTitle->getNamespace(),
                        'pt_title' => $this->mTitle->getDBkey()
                    ), __METHOD__
                );
            }
        }

        $this->mTitle->flushRestrictions();
        InfoAction::invalidateCache( $this->mTitle );

        if ( $logAction == 'unprotect' ) {
            $params = array();
        } else {
            $protectDescriptionLog = $this->protectDescriptionLog( $limit, $expiry );
            $params = array( $protectDescriptionLog, $cascade ? 'cascade' : '' );
        }

        // Update the protection log
        $log = new LogPage( 'protect' );
        $log->addEntry( $logAction, $this->mTitle, trim( $reason ), $params, $user );

        return Status::newGood();
    }

    public function insertProtectNullRevision( $revCommentMsg, array $limit, array $expiry, $cascade, $reason ) {
        global $wgContLang;
        $dbw = wfGetDB( DB_MASTER );

        // Prepare a null revision to be added to the history
        $editComment = $wgContLang->ucfirst(
            wfMessage(
                $revCommentMsg,
                $this->mTitle->getPrefixedText()
            )->inContentLanguage()->text()
        );
        if ( $reason ) {
            $editComment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
        }
        $protectDescription = $this->protectDescription( $limit, $expiry );
        if ( $protectDescription ) {
            $editComment .= wfMessage( 'word-separator' )->inContentLanguage()->text();
            $editComment .= wfMessage( 'parentheses' )->params( $protectDescription )->inContentLanguage()->text();
        }
        if ( $cascade ) {
            $editComment .= wfMessage( 'word-separator' )->inContentLanguage()->text();
            $editComment .= wfMessage( 'brackets' )->params(
                wfMessage( 'protect-summary-cascade' )->inContentLanguage()->text()
            )->inContentLanguage()->text();
        }

        $nullRev = Revision::newNullRevision( $dbw, $this->getId(), $editComment, true );
        if ( $nullRev ) {
            $nullRev->insertOn( $dbw );

            // Update page record and touch page
            $oldLatest = $nullRev->getParentId();
            $this->updateRevisionOn( $dbw, $nullRev, $oldLatest );
        }

        return $nullRev;
    }

    protected function formatExpiry( $expiry ) {
        global $wgContLang;
        $dbr = wfGetDB( DB_SLAVE );

        $encodedExpiry = $dbr->encodeExpiry( $expiry );
        if ( $encodedExpiry != 'infinity' ) {
            return wfMessage(
                'protect-expiring',
                $wgContLang->timeanddate( $expiry, false, false ),
                $wgContLang->date( $expiry, false, false ),
                $wgContLang->time( $expiry, false, false )
            )->inContentLanguage()->text();
        } else {
            return wfMessage( 'protect-expiry-indefinite' )
                ->inContentLanguage()->text();
        }
    }

    public function protectDescription( array $limit, array $expiry ) {
        $protectDescription = '';

        foreach ( array_filter( $limit ) as $action => $restrictions ) {
            # $action is one of $wgRestrictionTypes = array( 'create', 'edit', 'move', 'upload' ).
            # All possible message keys are listed here for easier grepping:
            # * restriction-create
            # * restriction-edit
            # * restriction-move
            # * restriction-upload
            $actionText = wfMessage( 'restriction-' . $action )->inContentLanguage()->text();
            # $restrictions is one of $wgRestrictionLevels = array( '', 'autoconfirmed', 'sysop' ),
            # with '' filtered out. All possible message keys are listed below:
            # * protect-level-autoconfirmed
            # * protect-level-sysop
            $restrictionsText = wfMessage( 'protect-level-' . $restrictions )->inContentLanguage()->text();

            $expiryText = $this->formatExpiry( $expiry[$action] );

            if ( $protectDescription !== '' ) {
                $protectDescription .= wfMessage( 'word-separator' )->inContentLanguage()->text();
            }
            $protectDescription .= wfMessage( 'protect-summary-desc' )
                ->params( $actionText, $restrictionsText, $expiryText )
                ->inContentLanguage()->text();
        }

        return $protectDescription;
    }

    public function protectDescriptionLog( array $limit, array $expiry ) {
        global $wgContLang;

        $protectDescriptionLog = '';

        foreach ( array_filter( $limit ) as $action => $restrictions ) {
            $expiryText = $this->formatExpiry( $expiry[$action] );
            $protectDescriptionLog .= $wgContLang->getDirMark() . "[$action=$restrictions] ($expiryText)";
        }

        return trim( $protectDescriptionLog );
    }

    protected static function flattenRestrictions( $limit ) {
        if ( !is_array( $limit ) ) {
            throw new MWException( 'WikiPage::flattenRestrictions given non-array restriction set' );
        }

        $bits = array();
        ksort( $limit );

        foreach ( array_filter( $limit ) as $action => $restrictions ) {
            $bits[] = "$action=$restrictions";
        }

        return implode( ':', $bits );
    }

    public function doDeleteArticle(
        $reason, $suppress = false, $id = 0, $commit = true, &$error = '', User $user = null
    ) {
        $status = $this->doDeleteArticleReal( $reason, $suppress, $id, $commit, $error, $user );
        return $status->isGood();
    }

    public function doDeleteArticleReal(
        $reason, $suppress = false, $id = 0, $commit = true, &$error = '', User $user = null
    ) {
        global $wgUser, $wgContentHandlerUseDB;

        wfDebug( __METHOD__ . "\n" );

        $status = Status::newGood();

        if ( $this->mTitle->getDBkey() === '' ) {
            $status->error( 'cannotdelete', wfEscapeWikiText( $this->getTitle()->getPrefixedText() ) );
            return $status;
        }

        $user = is_null( $user ) ? $wgUser : $user;
        if ( ! wfRunHooks( 'ArticleDelete', array( &$this, &$user, &$reason, &$error, &$status ) ) ) {
            if ( $status->isOK() ) {
                // Hook aborted but didn't set a fatal status
                $status->fatal( 'delete-hook-aborted' );
            }
            return $status;
        }

        if ( $id == 0 ) {
            $this->loadPageData( 'forupdate' );
            $id = $this->getID();
            if ( $id == 0 ) {
                $status->error( 'cannotdelete', wfEscapeWikiText( $this->getTitle()->getPrefixedText() ) );
                return $status;
            }
        }

        // Bitfields to further suppress the content
        if ( $suppress ) {
            $bitfield = 0;
            // This should be 15...
            $bitfield |= Revision::DELETED_TEXT;
            $bitfield |= Revision::DELETED_COMMENT;
            $bitfield |= Revision::DELETED_USER;
            $bitfield |= Revision::DELETED_RESTRICTED;
        } else {
            $bitfield = 'rev_deleted';
        }

        // we need to remember the old content so we can use it to generate all deletion updates.
        $content = $this->getContent( Revision::RAW );

        $dbw = wfGetDB( DB_MASTER );
        $dbw->begin( __METHOD__ );
        // For now, shunt the revision data into the archive table.
        // Text is *not* removed from the text table; bulk storage
        // is left intact to avoid breaking block-compression or
        // immutable storage schemes.
        //
        // For backwards compatibility, note that some older archive
        // table entries will have ar_text and ar_flags fields still.
        //
        // In the future, we may keep revisions and mark them with
        // the rev_deleted field, which is reserved for this purpose.

        $row = array(
            'ar_namespace'  => 'page_namespace',
            'ar_title'      => 'page_title',
            'ar_comment'    => 'rev_comment',
            'ar_user'       => 'rev_user',
            'ar_user_text'  => 'rev_user_text',
            'ar_timestamp'  => 'rev_timestamp',
            'ar_minor_edit' => 'rev_minor_edit',
            'ar_rev_id'     => 'rev_id',
            'ar_parent_id'  => 'rev_parent_id',
            'ar_text_id'    => 'rev_text_id',
            'ar_text'       => '\'\'', // Be explicit to appease
            'ar_flags'      => '\'\'', // MySQL's "strict mode"...
            'ar_len'        => 'rev_len',
            'ar_page_id'    => 'page_id',
            'ar_deleted'    => $bitfield,
            'ar_sha1'       => 'rev_sha1',
        );

        if ( $wgContentHandlerUseDB ) {
            $row['ar_content_model'] = 'rev_content_model';
            $row['ar_content_format'] = 'rev_content_format';
        }

        $dbw->insertSelect( 'archive', array( 'page', 'revision' ),
            $row,
            array(
                'page_id' => $id,
                'page_id = rev_page'
            ), __METHOD__
        );

        // Now that it's safely backed up, delete it
        $dbw->delete( 'page', array( 'page_id' => $id ), __METHOD__ );
        $ok = ( $dbw->affectedRows() > 0 ); // $id could be laggy

        if ( !$ok ) {
            $dbw->rollback( __METHOD__ );
            $status->error( 'cannotdelete', wfEscapeWikiText( $this->getTitle()->getPrefixedText() ) );
            return $status;
        }

        if ( !$dbw->cascadingDeletes() ) {
            $dbw->delete( 'revision', array( 'rev_page' => $id ), __METHOD__ );
        }

        $this->doDeleteUpdates( $id, $content );

        // Log the deletion, if the page was suppressed, log it at Oversight instead
        $logtype = $suppress ? 'suppress' : 'delete';

        $logEntry = new ManualLogEntry( $logtype, 'delete' );
        $logEntry->setPerformer( $user );
        $logEntry->setTarget( $this->mTitle );
        $logEntry->setComment( $reason );
        $logid = $logEntry->insert();
        $logEntry->publish( $logid );

        if ( $commit ) {
            $dbw->commit( __METHOD__ );
        }

        wfRunHooks( 'ArticleDeleteComplete', array( &$this, &$user, $reason, $id, $content, $logEntry ) );
        $status->value = $logid;
        return $status;
    }

    public function doDeleteUpdates( $id, Content $content = null ) {
        // update site status
        DeferredUpdates::addUpdate( new SiteStatsUpdate( 0, 1, - (int)$this->isCountable(), -1 ) );

        // remove secondary indexes, etc
        $updates = $this->getDeletionUpdates( $content );
        DataUpdate::runUpdates( $updates );

        // Clear caches
        WikiPage::onArticleDelete( $this->mTitle );

        // Reset this object and the Title object
        $this->loadFromRow( false, self::READ_LATEST );

        // Search engine
        DeferredUpdates::addUpdate( new SearchUpdate( $id, $this->mTitle ) );
    }

    public function doRollback(
        $fromP, $summary, $token, $bot, &$resultDetails, User $user
    ) {
        $resultDetails = null;

        // Check permissions
        $editErrors = $this->mTitle->getUserPermissionsErrors( 'edit', $user );
        $rollbackErrors = $this->mTitle->getUserPermissionsErrors( 'rollback', $user );
        $errors = array_merge( $editErrors, wfArrayDiff2( $rollbackErrors, $editErrors ) );

        if ( !$user->matchEditToken( $token, array( $this->mTitle->getPrefixedText(), $fromP ) ) ) {
            $errors[] = array( 'sessionfailure' );
        }

        if ( $user->pingLimiter( 'rollback' ) || $user->pingLimiter() ) {
            $errors[] = array( 'actionthrottledtext' );
        }

        // If there were errors, bail out now
        if ( !empty( $errors ) ) {
            return $errors;
        }

        return $this->commitRollback( $fromP, $summary, $bot, $resultDetails, $user );
    }

    public function commitRollback( $fromP, $summary, $bot, &$resultDetails, User $guser ) {
        global $wgUseRCPatrol, $wgContLang;

        $dbw = wfGetDB( DB_MASTER );

        if ( wfReadOnly() ) {
            return array( array( 'readonlytext' ) );
        }

        // Get the last editor
        $current = $this->getRevision();
        if ( is_null( $current ) ) {
            // Something wrong... no page?
            return array( array( 'notanarticle' ) );
        }

        $from = str_replace( '_', ' ', $fromP );
        // User name given should match up with the top revision.
        // If the user was deleted then $from should be empty.
        if ( $from != $current->getUserText() ) {
            $resultDetails = array( 'current' => $current );
            return array( array( 'alreadyrolled',
                htmlspecialchars( $this->mTitle->getPrefixedText() ),
                htmlspecialchars( $fromP ),
                htmlspecialchars( $current->getUserText() )
            ) );
        }

        // Get the last edit not by this guy...
        // Note: these may not be public values
        $user = intval( $current->getRawUser() );
        $user_text = $dbw->addQuotes( $current->getRawUserText() );
        $s = $dbw->selectRow( 'revision',
            array( 'rev_id', 'rev_timestamp', 'rev_deleted' ),
            array( 'rev_page' => $current->getPage(),
                "rev_user != {$user} OR rev_user_text != {$user_text}"
            ), __METHOD__,
            array( 'USE INDEX' => 'page_timestamp',
                'ORDER BY' => 'rev_timestamp DESC' )
            );
        if ( $s === false ) {
            // No one else ever edited this page
            return array( array( 'cantrollback' ) );
        } elseif ( $s->rev_deleted & Revision::DELETED_TEXT || $s->rev_deleted & Revision::DELETED_USER ) {
            // Only admins can see this text
            return array( array( 'notvisiblerev' ) );
        }

        $set = array();
        if ( $bot && $guser->isAllowed( 'markbotedits' ) ) {
            // Mark all reverted edits as bot
            $set['rc_bot'] = 1;
        }

        if ( $wgUseRCPatrol ) {
            // Mark all reverted edits as patrolled
            $set['rc_patrolled'] = 1;
        }

        if ( count( $set ) ) {
            $dbw->update( 'recentchanges', $set,
                array( /* WHERE */
                    'rc_cur_id' => $current->getPage(),
                    'rc_user_text' => $current->getUserText(),
                    'rc_timestamp > ' . $dbw->addQuotes( $s->rev_timestamp ),
                ), __METHOD__
            );
        }

        // Generate the edit summary if necessary
        $target = Revision::newFromId( $s->rev_id );
        if ( empty( $summary ) ) {
            if ( $from == '' ) { // no public user name
                $summary = wfMessage( 'revertpage-nouser' );
            } else {
                $summary = wfMessage( 'revertpage' );
            }
        }

        // Allow the custom summary to use the same args as the default message
        $args = array(
            $target->getUserText(), $from, $s->rev_id,
            $wgContLang->timeanddate( wfTimestamp( TS_MW, $s->rev_timestamp ) ),
            $current->getId(), $wgContLang->timeanddate( $current->getTimestamp() )
        );
        if ( $summary instanceof Message ) {
            $summary = $summary->params( $args )->inContentLanguage()->text();
        } else {
            $summary = wfMsgReplaceArgs( $summary, $args );
        }

        // Trim spaces on user supplied text
        $summary = trim( $summary );

        // Truncate for whole multibyte characters.
        $summary = $wgContLang->truncate( $summary, 255 );

        // Save
        $flags = EDIT_UPDATE;

        if ( $guser->isAllowed( 'minoredit' ) ) {
            $flags |= EDIT_MINOR;
        }

        if ( $bot && ( $guser->isAllowedAny( 'markbotedits', 'bot' ) ) ) {
            $flags |= EDIT_FORCE_BOT;
        }

        // Actually store the edit
        $status = $this->doEditContent( $target->getContent(), $summary, $flags, $target->getId(), $guser );

        if ( !$status->isOK() ) {
            return $status->getErrorsArray();
        }

        if ( !empty( $status->value['revision'] ) ) {
            $revId = $status->value['revision']->getId();
        } else {
            $revId = false;
        }

        wfRunHooks( 'ArticleRollbackComplete', array( $this, $guser, $target, $current ) );

        $resultDetails = array(
            'summary' => $summary,
            'current' => $current,
            'target' => $target,
            'newid' => $revId
        );

        return array();
    }

    public static function onArticleCreate( $title ) {
        // Update existence markers on article/talk tabs...
        if ( $title->isTalkPage() ) {
            $other = $title->getSubjectPage();
        } else {
            $other = $title->getTalkPage();
        }

        $other->invalidateCache();
        $other->purgeSquid();

        $title->touchLinks();
        $title->purgeSquid();
        $title->deleteTitleProtection();
    }

    public static function onArticleDelete( $title ) {
        // Update existence markers on article/talk tabs...
        if ( $title->isTalkPage() ) {
            $other = $title->getSubjectPage();
        } else {
            $other = $title->getTalkPage();
        }

        $other->invalidateCache();
        $other->purgeSquid();

        $title->touchLinks();
        $title->purgeSquid();

        // File cache
        HTMLFileCache::clearFileCache( $title );
        InfoAction::invalidateCache( $title );

        // Messages
        if ( $title->getNamespace() == NS_MEDIAWIKI ) {
            MessageCache::singleton()->replace( $title->getDBkey(), false );
        }

        // Images
        if ( $title->getNamespace() == NS_FILE ) {
            $update = new HTMLCacheUpdate( $title, 'imagelinks' );
            $update->doUpdate();
        }

        // User talk pages
        if ( $title->getNamespace() == NS_USER_TALK ) {
            $user = User::newFromName( $title->getText(), false );
            if ( $user ) {
                $user->setNewtalk( false );
            }
        }

        // Image redirects
        RepoGroup::singleton()->getLocalRepo()->invalidateImageRedirect( $title );
    }

    public static function onArticleEdit( $title ) {
        // Invalidate caches of articles which include this page
        DeferredUpdates::addHTMLCacheUpdate( $title, 'templatelinks' );

        // Invalidate the caches of all pages which redirect here
        DeferredUpdates::addHTMLCacheUpdate( $title, 'redirect' );

        // Purge squid for this page only
        $title->purgeSquid();

        // Clear file cache for this page only
        HTMLFileCache::clearFileCache( $title );
        InfoAction::invalidateCache( $title );
    }

    public function getCategories() {
        $id = $this->getId();
        if ( $id == 0 ) {
            return TitleArray::newFromResult( new FakeResultWrapper( array() ) );
        }

        $dbr = wfGetDB( DB_SLAVE );
        $res = $dbr->select( 'categorylinks',
            array( 'cl_to AS page_title, ' . NS_CATEGORY . ' AS page_namespace' ),
            // Have to do that since DatabaseBase::fieldNamesWithAlias treats numeric indexes
            // as not being aliases, and NS_CATEGORY is numeric
            array( 'cl_from' => $id ),
            __METHOD__ );

        return TitleArray::newFromResult( $res );
    }

    public function getHiddenCategories() {
        $result = array();
        $id = $this->getId();

        if ( $id == 0 ) {
            return array();
        }

        $dbr = wfGetDB( DB_SLAVE );
        $res = $dbr->select( array( 'categorylinks', 'page_props', 'page' ),
            array( 'cl_to' ),
            array( 'cl_from' => $id, 'pp_page=page_id', 'pp_propname' => 'hiddencat',
                'page_namespace' => NS_CATEGORY, 'page_title=cl_to' ),
            __METHOD__ );

        if ( $res !== false ) {
            foreach ( $res as $row ) {
                $result[] = Title::makeTitle( NS_CATEGORY, $row->cl_to );
            }
        }

        return $result;
    }

    public static function getAutosummary( $oldtext, $newtext, $flags ) {
        // NOTE: stub for backwards-compatibility. assumes the given text is wikitext. will break horribly if it isn't.

        ContentHandler::deprecated( __METHOD__, '1.21' );

        $handler = ContentHandler::getForModelID( CONTENT_MODEL_WIKITEXT );
        $oldContent = is_null( $oldtext ) ? null : $handler->unserializeContent( $oldtext );
        $newContent = is_null( $newtext ) ? null : $handler->unserializeContent( $newtext );

        return $handler->getAutosummary( $oldContent, $newContent, $flags );
    }

    public function getAutoDeleteReason( &$hasHistory ) {
        return $this->getContentHandler()->getAutoDeleteReason( $this->getTitle(), $hasHistory );
    }

    public function updateCategoryCounts( array $added, array $deleted ) {
        $that = $this;
        $method = __METHOD__;
        $dbw = wfGetDB( DB_MASTER );

        // Do this at the end of the commit to reduce lock wait timeouts
        $dbw->onTransactionPreCommitOrIdle(
            function() use ( $dbw, $that, $method, $added, $deleted ) {
                $ns = $that->getTitle()->getNamespace();

                $addFields = array( 'cat_pages = cat_pages + 1' );
                $removeFields = array( 'cat_pages = cat_pages - 1' );
                if ( $ns == NS_CATEGORY ) {
                    $addFields[] = 'cat_subcats = cat_subcats + 1';
                    $removeFields[] = 'cat_subcats = cat_subcats - 1';
                } elseif ( $ns == NS_FILE ) {
                    $addFields[] = 'cat_files = cat_files + 1';
                    $removeFields[] = 'cat_files = cat_files - 1';
                }

                if ( count( $added ) ) {
                    $insertRows = array();
                    foreach ( $added as $cat ) {
                        $insertRows[] = array(
                            'cat_title'   => $cat,
                            'cat_pages'   => 1,
                            'cat_subcats' => ( $ns == NS_CATEGORY ) ? 1 : 0,
                            'cat_files'   => ( $ns == NS_FILE ) ? 1 : 0,
                        );
                    }
                    $dbw->upsert(
                        'category',
                        $insertRows,
                        array( 'cat_title' ),
                        $addFields,
                        $method
                    );
                }

                if ( count( $deleted ) ) {
                    $dbw->update(
                        'category',
                        $removeFields,
                        array( 'cat_title' => $deleted ),
                        $method
                    );
                }

                foreach ( $added as $catName ) {
                    $cat = Category::newFromName( $catName );
                    wfRunHooks( 'CategoryAfterPageAdded', array( $cat, $that ) );
                }

                foreach ( $deleted as $catName ) {
                    $cat = Category::newFromName( $catName );
                    wfRunHooks( 'CategoryAfterPageRemoved', array( $cat, $that ) );
                }
            }
        );
    }

    public function doCascadeProtectionUpdates( ParserOutput $parserOutput ) {
        if ( wfReadOnly() || !$this->mTitle->areRestrictionsCascading() ) {
            return;
        }

        // templatelinks table may have become out of sync,
        // especially if using variable-based transclusions.
        // For paranoia, check if things have changed and if
        // so apply updates to the database. This will ensure
        // that cascaded protections apply as soon as the changes
        // are visible.

        // Get templates from templatelinks
        $id = $this->getId();

        $tlTemplates = array();

        $dbr = wfGetDB( DB_SLAVE );
        $res = $dbr->select( array( 'templatelinks' ),
            array( 'tl_namespace', 'tl_title' ),
            array( 'tl_from' => $id ),
            __METHOD__
        );

        foreach ( $res as $row ) {
            $tlTemplates["{$row->tl_namespace}:{$row->tl_title}"] = true;
        }

        // Get templates from parser output.
        $poTemplates = array();
        foreach ( $parserOutput->getTemplates() as $ns => $templates ) {
            foreach ( $templates as $dbk => $id ) {
                $poTemplates["$ns:$dbk"] = true;
            }
        }

        // Get the diff
        $templates_diff = array_diff_key( $poTemplates, $tlTemplates );

        if ( count( $templates_diff ) > 0 ) {
            // Whee, link updates time.
            // Note: we are only interested in links here. We don't need to get other DataUpdate items from the parser output.
            $u = new LinksUpdate( $this->mTitle, $parserOutput, false );
            $u->doUpdate();
        }
    }

    public function getUsedTemplates() {
        return $this->mTitle->getTemplateLinksFrom();
    }

    public function createUpdates( $rev ) {
        wfDeprecated( __METHOD__, '1.18' );
        global $wgUser;
        $this->doEditUpdates( $rev, $wgUser, array( 'created' => true ) );
    }

    public function preSaveTransform( $text, User $user = null, ParserOptions $popts = null ) {
        global $wgParser, $wgUser;

        wfDeprecated( __METHOD__, '1.19' );

        $user = is_null( $user ) ? $wgUser : $user;

        if ( $popts === null ) {
            $popts = ParserOptions::newFromUser( $user );
        }

        return $wgParser->preSaveTransform( $text, $this->mTitle, $user, $popts );
    }

    public function isBigDeletion() {
        wfDeprecated( __METHOD__, '1.19' );
        return $this->mTitle->isBigDeletion();
    }

    public function estimateRevisionCount() {
        wfDeprecated( __METHOD__, '1.19' );
        return $this->mTitle->estimateRevisionCount();
    }

    public function updateRestrictions(
        $limit = array(), $reason = '', &$cascade = 0, $expiry = array(), User $user = null
    ) {
        global $wgUser;

        $user = is_null( $user ) ? $wgUser : $user;

        return $this->doUpdateRestrictions( $limit, $expiry, $cascade, $reason, $user )->isOK();
    }

    public function quickEdit( $text, $comment = '', $minor = 0 ) {
        wfDeprecated( __METHOD__, '1.18' );
        global $wgUser;
        $this->doQuickEdit( $text, $wgUser, $comment, $minor );
    }

    public function viewUpdates() {
        wfDeprecated( __METHOD__, '1.18' );
        global $wgUser;
        $this->doViewUpdates( $wgUser );
    }

    public function useParserCache( $oldid ) {
        wfDeprecated( __METHOD__, '1.18' );
        global $wgUser;
        return $this->isParserCacheUsed( ParserOptions::newFromUser( $wgUser ), $oldid );
    }

    public function getDeletionUpdates( Content $content = null ) {
        if ( !$content ) {
            // load content object, which may be used to determine the necessary updates
            // XXX: the content may not be needed to determine the updates, then this would be overhead.
            $content = $this->getContent( Revision::RAW );
        }

        if ( !$content ) {
            $updates = array();
        } else {
            $updates = $content->getDeletionUpdates( $this );
        }

        wfRunHooks( 'WikiPageDeletionUpdates', array( $this, $content, &$updates ) );
        return $updates;
    }

}

class PoolWorkArticleView extends PoolCounterWork {

    private $page;

    private $cacheKey;

    private $revid;

    private $parserOptions;

    private $content = null;

    private $parserOutput = false;

    private $isDirty = false;

    private $error = false;

    function __construct( Page $page, ParserOptions $parserOptions, $revid, $useParserCache, $content = null ) {
        if ( is_string( $content ) ) { // BC: old style call
            $modelId = $page->getRevision()->getContentModel();
            $format = $page->getRevision()->getContentFormat();
            $content = ContentHandler::makeContent( $content, $page->getTitle(), $modelId, $format );
        }

        $this->page = $page;
        $this->revid = $revid;
        $this->cacheable = $useParserCache;
        $this->parserOptions = $parserOptions;
        $this->content = $content;
        $this->cacheKey = ParserCache::singleton()->getKey( $page, $parserOptions );
        parent::__construct( 'ArticleView', $this->cacheKey . ':revid:' . $revid );
    }

    public function getParserOutput() {
        return $this->parserOutput;
    }

    public function getIsDirty() {
        return $this->isDirty;
    }

    public function getError() {
        return $this->error;
    }

    function doWork() {
        global $wgUseFileCache;

        // @todo several of the methods called on $this->page are not declared in Page, but present
        //        in WikiPage and delegated by Article.

        $isCurrent = $this->revid === $this->page->getLatest();

        if ( $this->content !== null ) {
            $content = $this->content;
        } elseif ( $isCurrent ) {
            // XXX: why use RAW audience here, and PUBLIC (default) below?
            $content = $this->page->getContent( Revision::RAW );
        } else {
            $rev = Revision::newFromTitle( $this->page->getTitle(), $this->revid );

            if ( $rev === null ) {
                $content = null;
            } else {
                // XXX: why use PUBLIC audience here (default), and RAW above?
                $content = $rev->getContent();
            }
        }

        if ( $content === null ) {
            return false;
        }

        // Reduce effects of race conditions for slow parses (bug 46014)
        $cacheTime = wfTimestampNow();

        $time = - microtime( true );
        $this->parserOutput = $content->getParserOutput( $this->page->getTitle(), $this->revid, $this->parserOptions );
        $time += microtime( true );

        // Timing hack
        if ( $time > 3 ) {
            wfDebugLog( 'slow-parse', sprintf( "%-5.2f %s", $time,
                $this->page->getTitle()->getPrefixedDBkey() ) );
        }

        if ( $this->cacheable && $this->parserOutput->isCacheable() ) {
            ParserCache::singleton()->save(
                $this->parserOutput, $this->page, $this->parserOptions, $cacheTime );
        }

        // Make sure file cache is not used on uncacheable content.
        // Output that has magic words in it can still use the parser cache
        // (if enabled), though it will generally expire sooner.
        if ( !$this->parserOutput->isCacheable() || $this->parserOutput->containsOldMagic() ) {
            $wgUseFileCache = false;
        }

        if ( $isCurrent ) {
            $this->page->doCascadeProtectionUpdates( $this->parserOutput );
        }

        return true;
    }

    function getCachedWork() {
        $this->parserOutput = ParserCache::singleton()->get( $this->page, $this->parserOptions );

        if ( $this->parserOutput === false ) {
            wfDebug( __METHOD__ . ": parser cache miss\n" );
            return false;
        } else {
            wfDebug( __METHOD__ . ": parser cache hit\n" );
            return true;
        }
    }

    function fallback() {
        $this->parserOutput = ParserCache::singleton()->getDirty( $this->page, $this->parserOptions );

        if ( $this->parserOutput === false ) {
            wfDebugLog( 'dirty', "dirty missing\n" );
            wfDebug( __METHOD__ . ": no dirty cache\n" );
            return false;
        } else {
            wfDebug( __METHOD__ . ": sending dirty output\n" );
            wfDebugLog( 'dirty', "dirty output {$this->cacheKey}\n" );
            $this->isDirty = true;
            return true;
        }
    }

    function error( $status ) {
        $this->error = $status;
        return false;
    }
}