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 );
        } 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 );
            }
        }

        // If title is not provided, always allow oldid and diff to set the title.
        // If title is provided, allow oldid and diff to override the title, unless
        // we are talking about a special page which might use these parameters for
        // other purposes.
        if ( $ret === null || !$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;
            }
        }

        // Use the main page as default title if nothing else has been provided
        if ( $ret === null && strval( $title ) === '' && $action !== 'delete' ) {
            $ret = Title::newMainPage();
        }

        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( array( 'rdfrom' => $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, $this->context );

        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();

        // 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 the user has forceHTTPS set to true, or if the user
        // is in a group requiring HTTPS, or if they have the HTTPS
        // preference set, redirect them to HTTPS.
        // Note: Do this after $wgTitle is setup, otherwise the hooks run from
        // isLoggedIn() will do all sorts of weird stuff.
        if (
            (
                $request->getCookie( 'forceHTTPS', '' ) ||
                // check for prefixed version for currently logged in users
                $request->getCookie( 'forceHTTPS' ) ||
                // Avoid checking the user and groups unless it's enabled.
                (
                    $this->context->getUser()->isLoggedIn()
                    && $this->context->getUser()->requiresHTTPS()
                )
            ) &&
            $request->detectProtocol() == 'http'
        ) {
            $oldUrl = $request->getFullRequestURL();
            $redirUrl = str_replace( 'http://', 'https://', $oldUrl );

            if ( $request->wasPosted() ) {
                // This is weird and we'd hope it almost never happens. This
                // means that a POST came in via HTTP and policy requires us
                // redirecting to HTTPS. It's likely such a request is going
                // to fail due to post data being lost, but let's try anyway
                // and just log the instance.
                //
                // @todo @fixme See if we could issue a 307 or 308 here, need
                // to see how clients (automated & browser) behave when we do
                wfDebugLog( 'RedirectedPosts', "Redirected from HTTP to HTTPS: $oldUrl" );
            }

            // Setup dummy Title, otherwise OutputPage::redirect will fail
            $title = Title::newFromText( NS_MAIN, 'REDIR' );
            $this->context->setTitle( $title );
            $output = $this->context->getOutput();
            // Since we only do this redir to change proto, always send a vary header
            $output->addVaryHeader( 'X-Forwarded-Proto' );
            $output->redirect( $redirUrl );
            $output->output();
            wfProfileOut( __METHOD__ );
            return;
        }

        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, $wgPhpCli, $IP;

        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 );
        }

        if ( !wfShellExecDisabled() && is_executable( $wgPhpCli ) ) {
            // Start a background process to run some of the jobs
            wfProfileIn( __METHOD__ . '-exec' );
            $retVal = 1;
            $cmd = wfShellWikiCmd( "$IP/maintenance/runJobs.php", array( '--maxjobs', $n ) );
            $cmd .= " >" . wfGetNull() . " 2>&1"; // don't hang PHP on pipes
            if ( wfIsWindows() ) {
                // Using START makes this async and also works around a bug where using
                // wfShellExec() with a quoted script name causes a filename syntax error.
                $cmd = "START /B \"bg\" $cmd";
            } else {
                $cmd = "$cmd &";
            }
            wfShellExec( $cmd, $retVal );
            wfProfileOut( __METHOD__ . '-exec' );
        } else {
            try {
                // Fallback to running the jobs here while the user waits
                $group = JobQueueGroup::singleton();
                do {
                    $job = $group->pop( JobQueueGroup::USE_CACHE ); // job from any queue
                    if ( $job ) {
                        $output = $job->toString() . "\n";
                        $t = - microtime( true );
                        wfProfileIn( __METHOD__ . '-' . get_class( $job ) );
                        $success = $job->run();
                        wfProfileOut( __METHOD__ . '-' . get_class( $job ) );
                        $group->ack( $job ); // done
                        $t += microtime( true );
                        $t = round( $t * 1000 );
                        if ( $success === false ) {
                            $output .= "Error: " . $job->getLastError() . ", Time: $t ms\n";
                        } else {
                            $output .= "Success, Time: $t ms\n";
                        }
                        wfDebugLog( 'jobqueue', $output );
                    }
                } while ( --$n && $job );
            } catch ( MWException $e ) {
                // We don't want exceptions thrown during job execution to
                // be reported to the user since the output is already sent.
                // Instead we just log them.
                MWExceptionHandler::logException( $e );
            }
        }
    }
}