Wiki.php

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<?php
class MediaWiki {

        private $context;

        public function request( WebRequest $x = null ) {
                $old = $this->context->getRequest();
                $this->context->setRequest( $x );
                return $old;
        }

        public function output( OutputPage $x = null ) {
                $old = $this->context->getOutput();
                $this->context->setOutput( $x );
                return $old;
        }

        public function __construct( IContextSource $context = null ) {
                if ( !$context ) {
                        $context = RequestContext::getMain();
                }

                $this->context = $context;
        }

        private function parseTitle() {
                global $wgContLang;

                $request = $this->context->getRequest();
                $curid = $request->getInt( 'curid' );
                $title = $request->getVal( 'title' );
                $action = $request->getVal( 'action', 'view' );

                if ( $request->getCheck( 'search' ) ) {
                        // Compatibility with old search URLs which didn't use Special:Search
                        // Just check for presence here, so blank requests still
                        // show the search page when using ugly URLs (bug 8054).
                        $ret = SpecialPage::getTitleFor( 'Search' );
                } elseif ( $curid ) {
                        // URLs like this are generated by RC, because rc_title isn't always accurate
                        $ret = Title::newFromID( $curid );
                } elseif ( $title == '' && $action != 'delete' ) {
                        $ret = Title::newMainPage();
                } else {
                        $ret = Title::newFromURL( $title );
                        // Alias NS_MEDIA page URLs to NS_FILE...we only use NS_MEDIA
                        // in wikitext links to tell Parser to make a direct file link
                        if ( !is_null( $ret ) && $ret->getNamespace() == NS_MEDIA ) {
                                $ret = Title::makeTitle( NS_FILE, $ret->getDBkey() );
                        }
                        // Check variant links so that interwiki links don't have to worry
                        // about the possible different language variants
                        if ( count( $wgContLang->getVariants() ) > 1
                                && !is_null( $ret ) && $ret->getArticleID() == 0 )
                        {
                                $wgContLang->findVariantLink( $title, $ret );
                        }
                }
                // For non-special titles, check for implicit titles
                if ( is_null( $ret ) || !$ret->isSpecialPage() ) {
                        // We can have urls with just ?diff=,?oldid= or even just ?diff=
                        $oldid = $request->getInt( 'oldid' );
                        $oldid = $oldid ? $oldid : $request->getInt( 'diff' );
                        // Allow oldid to override a changed or missing title
                        if ( $oldid ) {
                                $rev = Revision::newFromId( $oldid );
                                $ret = $rev ? $rev->getTitle() : $ret;
                        }
                }

                if ( $ret === null || ( $ret->getDBkey() == '' && $ret->getInterwiki() == '' ) ) {
                        $ret = SpecialPage::getTitleFor( 'Badtitle' );
                }

                return $ret;
        }

        public function getTitle() {
                if( $this->context->getTitle() === null ) {
                        $this->context->setTitle( $this->parseTitle() );
                }
                return $this->context->getTitle();
        }

        public function getAction() {
                static $action = null;

                if ( $action === null ) {
                        $action = Action::getActionName( $this->context );
                }

                return $action;
        }

        public static function articleFromTitle( $title, IContextSource $context ) {
                wfDeprecated( __METHOD__, '1.18' );
                return Article::newFromTitle( $title, $context );
        }

        private function performRequest() {
                global $wgServer, $wgUsePathInfo, $wgTitle;

                wfProfileIn( __METHOD__ );

                $request = $this->context->getRequest();
                $requestTitle = $title = $this->context->getTitle();
                $output = $this->context->getOutput();
                $user = $this->context->getUser();

                if ( $request->getVal( 'printable' ) === 'yes' ) {
                        $output->setPrintable();
                }

                $unused = null; // To pass it by reference
                wfRunHooks( 'BeforeInitialize', array( &$title, &$unused, &$output, &$user, $request, $this ) );

                // Invalid titles. Bug 21776: The interwikis must redirect even if the page name is empty.
                if ( is_null( $title ) || ( $title->getDBkey() == '' && $title->getInterwiki() == '' ) ||
                        $title->isSpecial( 'Badtitle' ) )
                {
                        $this->context->setTitle( SpecialPage::getTitleFor( 'Badtitle' ) );
                        wfProfileOut( __METHOD__ );
                        throw new BadTitleError();
                }

                // Check user's permissions to read this page.
                // We have to check here to catch special pages etc.
                // We will check again in Article::view().
                $permErrors = $title->getUserPermissionsErrors( 'read', $user );
                if ( count( $permErrors ) ) {
                        // Bug 32276: allowing the skin to generate output with $wgTitle or
                        // $this->context->title set to the input title would allow anonymous users to
                        // determine whether a page exists, potentially leaking private data. In fact, the
                        // curid and oldid request  parameters would allow page titles to be enumerated even
                        // when they are not guessable. So we reset the title to Special:Badtitle before the
                        // permissions error is displayed.
                        //
                        // The skin mostly uses $this->context->getTitle() these days, but some extensions
                        // still use $wgTitle.

                        $badTitle = SpecialPage::getTitleFor( 'Badtitle' );
                        $this->context->setTitle( $badTitle );
                        $wgTitle = $badTitle;

                        wfProfileOut( __METHOD__ );
                        throw new PermissionsError( 'read', $permErrors );
                }

                $pageView = false; // was an article or special page viewed?

                // Interwiki redirects
                if ( $title->getInterwiki() != '' ) {
                        $rdfrom = $request->getVal( 'rdfrom' );
                        if ( $rdfrom ) {
                                $url = $title->getFullURL( 'rdfrom=' . urlencode( $rdfrom ) );
                        } else {
                                $query = $request->getValues();
                                unset( $query['title'] );
                                $url = $title->getFullURL( $query );
                        }
                        // Check for a redirect loop
                        if ( !preg_match( '/^' . preg_quote( $wgServer, '/' ) . '/', $url )
                                && $title->isLocal() )
                        {
                                // 301 so google et al report the target as the actual url.
                                $output->redirect( $url, 301 );
                        } else {
                                $this->context->setTitle( SpecialPage::getTitleFor( 'Badtitle' ) );
                                wfProfileOut( __METHOD__ );
                                throw new BadTitleError();
                        }
                // Redirect loops, no title in URL, $wgUsePathInfo URLs, and URLs with a variant
                } elseif ( $request->getVal( 'action', 'view' ) == 'view' && !$request->wasPosted()
                        && ( $request->getVal( 'title' ) === null ||
                                $title->getPrefixedDBkey() != $request->getVal( 'title' ) )
                        && !count( $request->getValueNames( array( 'action', 'title' ) ) )
                        && wfRunHooks( 'TestCanonicalRedirect', array( $request, $title, $output ) ) )
                {
                        if ( $title->isSpecialPage() ) {
                                list( $name, $subpage ) = SpecialPageFactory::resolveAlias( $title->getDBkey() );
                                if ( $name ) {
                                        $title = SpecialPage::getTitleFor( $name, $subpage );
                                }
                        }
                        $targetUrl = wfExpandUrl( $title->getFullURL(), PROTO_CURRENT );
                        // Redirect to canonical url, make it a 301 to allow caching
                        if ( $targetUrl == $request->getFullRequestURL() ) {
                                $message = "Redirect loop detected!\n\n" .
                                        "This means the wiki got confused about what page was " .
                                        "requested; this sometimes happens when moving a wiki " .
                                        "to a new server or changing the server configuration.\n\n";

                                if ( $wgUsePathInfo ) {
                                        $message .= "The wiki is trying to interpret the page " .
                                                "title from the URL path portion (PATH_INFO), which " .
                                                "sometimes fails depending on the web server. Try " .
                                                "setting \"\$wgUsePathInfo = false;\" in your " .
                                                "LocalSettings.php, or check that \$wgArticlePath " .
                                                "is correct.";
                                } else {
                                        $message .= "Your web server was detected as possibly not " .
                                                "supporting URL path components (PATH_INFO) correctly; " .
                                                "check your LocalSettings.php for a customized " .
                                                "\$wgArticlePath setting and/or toggle \$wgUsePathInfo " .
                                                "to true.";
                                }
                                throw new HttpError( 500, $message );
                        } else {
                                $output->setSquidMaxage( 1200 );
                                $output->redirect( $targetUrl, '301' );
                        }
                // Special pages
                } elseif ( NS_SPECIAL == $title->getNamespace() ) {
                        $pageView = true;
                        // Actions that need to be made when we have a special pages
                        SpecialPageFactory::executePath( $title, $this->context );
                } else {
                        // ...otherwise treat it as an article view. The article
                        // may be a redirect to another article or URL.
                        $article = $this->initializeArticle();
                        if ( is_object( $article ) ) {
                                $pageView = true;
                                global $wgArticle;
                                $wgArticle = new DeprecatedGlobal( 'wgArticle', $article, '1.18' );

                                $this->performAction( $article, $requestTitle );
                        } elseif ( is_string( $article ) ) {
                                $output->redirect( $article );
                        } else {
                                wfProfileOut( __METHOD__ );
                                throw new MWException( "Shouldn't happen: MediaWiki::initializeArticle() returned neither an object nor a URL" );
                        }
                }

                if ( $pageView ) {
                        // Promote user to any groups they meet the criteria for
                        $user->addAutopromoteOnceGroups( 'onView' );
                }

                wfProfileOut( __METHOD__ );
        }

        private function initializeArticle() {
                global $wgDisableHardRedirects;

                wfProfileIn( __METHOD__ );

                $title = $this->context->getTitle();
                if ( $this->context->canUseWikiPage() ) {
                        // Try to use request context wiki page, as there
                        // is already data from db saved in per process
                        // cache there from this->getAction() call.
                        $page = $this->context->getWikiPage();
                        $article = Article::newFromWikiPage( $page, $this->context );
                } else {
                        // This case should not happen, but just in case.
                        $article = Article::newFromTitle( $title, $this->context );
                        $this->context->setWikiPage( $article->getPage() );
                }

                // NS_MEDIAWIKI has no redirects.
                // It is also used for CSS/JS, so performance matters here...
                if ( $title->getNamespace() == NS_MEDIAWIKI ) {
                        wfProfileOut( __METHOD__ );
                        return $article;
                }

                $request = $this->context->getRequest();

                // Namespace might change when using redirects
                // Check for redirects ...
                $action = $request->getVal( 'action', 'view' );
                $file = ( $title->getNamespace() == NS_FILE ) ? $article->getFile() : null;
                if ( ( $action == 'view' || $action == 'render' ) // ... for actions that show content
                        && !$request->getVal( 'oldid' ) && // ... and are not old revisions
                        !$request->getVal( 'diff' ) && // ... and not when showing diff
                        $request->getVal( 'redirect' ) != 'no' && // ... unless explicitly told not to
                        // ... and the article is not a non-redirect image page with associated file
                        !( is_object( $file ) && $file->exists() && !$file->getRedirected() ) )
                {
                        // Give extensions a change to ignore/handle redirects as needed
                        $ignoreRedirect = $target = false;

                        wfRunHooks( 'InitializeArticleMaybeRedirect',
                                array( &$title, &$request, &$ignoreRedirect, &$target, &$article ) );

                        // Follow redirects only for... redirects.
                        // If $target is set, then a hook wanted to redirect.
                        if ( !$ignoreRedirect && ( $target || $article->isRedirect() ) ) {
                                // Is the target already set by an extension?
                                $target = $target ? $target : $article->followRedirect();
                                if ( is_string( $target ) ) {
                                        if ( !$wgDisableHardRedirects ) {
                                                // we'll need to redirect
                                                wfProfileOut( __METHOD__ );
                                                return $target;
                                        }
                                }
                                if ( is_object( $target ) ) {
                                        // Rewrite environment to redirected article
                                        $rarticle = Article::newFromTitle( $target, $this->context );
                                        $rarticle->loadPageData();
                                        if ( $rarticle->exists() || ( is_object( $file ) && !$file->isLocal() ) ) {
                                                $rarticle->setRedirectedFrom( $title );
                                                $article = $rarticle;
                                                $this->context->setTitle( $target );
                                                $this->context->setWikiPage( $article->getPage() );
                                        }
                                }
                        } else {
                                $this->context->setTitle( $article->getTitle() );
                                $this->context->setWikiPage( $article->getPage() );
                        }
                }

                wfProfileOut( __METHOD__ );
                return $article;
        }

        private function performAction( Page $page, Title $requestTitle ) {
                global $wgUseSquid, $wgSquidMaxage;

                wfProfileIn( __METHOD__ );

                $request = $this->context->getRequest();
                $output = $this->context->getOutput();
                $title = $this->context->getTitle();
                $user = $this->context->getUser();

                if ( !wfRunHooks( 'MediaWikiPerformAction',
                        array( $output, $page, $title, $user, $request, $this ) ) )
                {
                        wfProfileOut( __METHOD__ );
                        return;
                }

                $act = $this->getAction();

                $action = Action::factory( $act, $page );
                if ( $action instanceof Action ) {
                        # Let Squid cache things if we can purge them.
                        if ( $wgUseSquid &&
                                in_array( $request->getFullRequestURL(), $requestTitle->getSquidURLs() )
                        ) {
                                $output->setSquidMaxage( $wgSquidMaxage );
                        }

                        $action->show();
                        wfProfileOut( __METHOD__ );
                        return;
                }

                if ( wfRunHooks( 'UnknownAction', array( $request->getVal( 'action', 'view' ), $page ) ) ) {
                        $output->showErrorPage( 'nosuchaction', 'nosuchactiontext' );
                }

                wfProfileOut( __METHOD__ );
        }

        public function run() {
                try {
                        $this->checkMaxLag();
                        $this->main();
                        $this->restInPeace();
                } catch ( Exception $e ) {
                        MWExceptionHandler::handle( $e );
                }
        }

        private function checkMaxLag() {
                global $wgShowHostnames;

                wfProfileIn( __METHOD__ );
                $maxLag = $this->context->getRequest()->getVal( 'maxlag' );
                if ( !is_null( $maxLag ) ) {
                        list( $host, $lag ) = wfGetLB()->getMaxLag();
                        if ( $lag > $maxLag ) {
                                $resp = $this->context->getRequest()->response();
                                $resp->header( 'HTTP/1.1 503 Service Unavailable' );
                                $resp->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
                                $resp->header( 'X-Database-Lag: ' . intval( $lag ) );
                                $resp->header( 'Content-Type: text/plain' );
                                if( $wgShowHostnames ) {
                                        echo "Waiting for $host: $lag seconds lagged\n";
                                } else {
                                        echo "Waiting for a database server: $lag seconds lagged\n";
                                }

                                wfProfileOut( __METHOD__ );

                                exit;
                        }
                }
                wfProfileOut( __METHOD__ );
                return true;
        }

        private function main() {
                global $wgUseFileCache, $wgTitle, $wgUseAjax;

                wfProfileIn( __METHOD__ );

                $request = $this->context->getRequest();

                if ( $request->getCookie( 'forceHTTPS' )
                        && $request->detectProtocol() == 'http'
                        && $request->getMethod() == 'GET'
                ) {
                        $redirUrl = $request->getFullRequestURL();
                        $redirUrl = str_replace( 'http://', 'https://', $redirUrl );

                        // Setup dummy Title, otherwise OutputPage::redirect will fail
                        $title = Title::newFromText( NS_MAIN, 'REDIR' );
                        $this->context->setTitle( $title );
                        $output = $this->context->getOutput();
                        $output->redirect( $redirUrl );
                        $output->output();
                        wfProfileOut( __METHOD__ );
                        return;
                }

                // Send Ajax requests to the Ajax dispatcher.
                if ( $wgUseAjax && $request->getVal( 'action', 'view' ) == 'ajax' ) {

                        // Set a dummy title, because $wgTitle == null might break things
                        $title = Title::makeTitle( NS_MAIN, 'AJAX' );
                        $this->context->setTitle( $title );
                        $wgTitle = $title;

                        $dispatcher = new AjaxDispatcher();
                        $dispatcher->performAction();
                        wfProfileOut( __METHOD__ );
                        return;
                }

                // Get title from request parameters,
                // is set on the fly by parseTitle the first time.
                $title = $this->getTitle();
                $action = $this->getAction();
                $wgTitle = $title;

                if ( $wgUseFileCache && $title->getNamespace() >= 0 ) {
                        wfProfileIn( 'main-try-filecache' );
                        if ( HTMLFileCache::useFileCache( $this->context ) ) {
                                // Try low-level file cache hit
                                $cache = HTMLFileCache::newFromTitle( $title, $action );
                                if ( $cache->isCacheGood( /* Assume up to date */ ) ) {
                                        // Check incoming headers to see if client has this cached
                                        $timestamp = $cache->cacheTimestamp();
                                        if ( !$this->context->getOutput()->checkLastModified( $timestamp ) ) {
                                                $cache->loadFromFileCache( $this->context );
                                        }
                                        // Do any stats increment/watchlist stuff
                                        $this->context->getWikiPage()->doViewUpdates( $this->context->getUser() );
                                        // Tell OutputPage that output is taken care of
                                        $this->context->getOutput()->disable();
                                        wfProfileOut( 'main-try-filecache' );
                                        wfProfileOut( __METHOD__ );
                                        return;
                                }
                        }
                        wfProfileOut( 'main-try-filecache' );
                }

                $this->performRequest();

                // Now commit any transactions, so that unreported errors after
                // output() don't roll back the whole DB transaction
                wfGetLBFactory()->commitMasterChanges();

                // Output everything!
                $this->context->getOutput()->output();

                wfProfileOut( __METHOD__ );
        }

        public function restInPeace() {
                // Do any deferred jobs
                DeferredUpdates::doUpdates( 'commit' );

                // Execute a job from the queue
                $this->doJobs();

                // Log profiling data, e.g. in the database or UDP
                wfLogProfilingData();

                // Commit and close up!
                $factory = wfGetLBFactory();
                $factory->commitMasterChanges();
                $factory->shutdown();

                wfDebug( "Request ended normally\n" );
        }

        private function doJobs() {
                global $wgJobRunRate;

                if ( $wgJobRunRate <= 0 || wfReadOnly() ) {
                        return;
                }

                if ( $wgJobRunRate < 1 ) {
                        $max = mt_getrandmax();
                        if ( mt_rand( 0, $max ) > $max * $wgJobRunRate ) {
                                return; // the higher $wgJobRunRate, the less likely we return here
                        }
                        $n = 1;
                } else {
                        $n = intval( $wgJobRunRate );
                }

                $group = JobQueueGroup::singleton();
                do {
                        $job = $group->pop( JobQueueGroup::USE_CACHE ); // job from any queue
                        if ( $job ) {
                                $output = $job->toString() . "\n";
                                $t = - microtime( true );
                                $success = $job->run();
                                $group->ack( $job ); // done
                                $t += microtime( true );
                                $t = round( $t * 1000 );
                                if ( !$success ) {
                                        $output .= "Error: " . $job->getLastError() . ", Time: $t ms\n";
                                } else {
                                        $output .= "Success, Time: $t ms\n";
                                }
                                wfDebugLog( 'jobqueue', $output );
                        }
                } while ( --$n && $job );
        }
}