wikimedia/mediawiki-core

<?php
/**
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiServices;
use MediaWiki\Status\Status;
use MediaWiki\Title\Title;
use Wikimedia\Rdbms\IDBAccessObject;

/**
 * Job for asynchronous rendering of thumbnails, e.g. after new uploads.
 *
 * @ingroup JobQueue
 */
class ThumbnailRenderJob extends Job {
    public function __construct( Title $title, array $params ) {
        parent::__construct( 'ThumbnailRender', $title, $params );
    }

    public function run() {
        $uploadThumbnailRenderMethod = MediaWikiServices::getInstance()
            ->getMainConfig()->get( MainConfigNames::UploadThumbnailRenderMethod );

        $transformParams = $this->params['transformParams'];

        $file = MediaWikiServices::getInstance()->getRepoGroup()->getLocalRepo()
            ->newFile( $this->title );
        $file->load( IDBAccessObject::READ_LATEST );

        if ( $file && $file->exists() ) {
            if ( $uploadThumbnailRenderMethod === 'jobqueue' ) {
                $thumb = $file->transform( $transformParams, File::RENDER_NOW );

                if ( !$thumb || $thumb->isError() ) {
                    if ( $thumb instanceof MediaTransformError ) {
                        $this->setLastError( __METHOD__ . ': thumbnail couldn\'t be generated:' .
                            $thumb->toText() );
                    } else {
                        $this->setLastError( __METHOD__ . ': thumbnail couldn\'t be generated' );
                    }
                    return false;
                }
                $this->maybeEnqueueNextPage( $transformParams );
                return true;
            } elseif ( $uploadThumbnailRenderMethod === 'http' ) {
                $res = $this->hitThumbUrl( $file, $transformParams );
                $this->maybeEnqueueNextPage( $transformParams );
                return $res;
            } else {
                $this->setLastError( __METHOD__ . ': unknown thumbnail render method ' .
                    $uploadThumbnailRenderMethod );
                return false;
            }
        } else {
            $this->setLastError( __METHOD__ . ': file doesn\'t exist' );
            return false;
        }
    }

    /**
     * @param LocalFile $file
     * @param array $transformParams
     * @return bool Success status (error will be set via setLastError() when false)
     */
    protected function hitThumbUrl( LocalFile $file, $transformParams ) {
        $config = MediaWikiServices::getInstance()->getMainConfig();
        $uploadThumbnailRenderHttpCustomHost =
            $config->get( MainConfigNames::UploadThumbnailRenderHttpCustomHost );
        $uploadThumbnailRenderHttpCustomDomain =
            $config->get( MainConfigNames::UploadThumbnailRenderHttpCustomDomain );
        $handler = $file->getHandler();
        if ( !$handler ) {
            $this->setLastError( __METHOD__ . ': could not get handler' );
            return false;
        } elseif ( !$handler->normaliseParams( $file, $transformParams ) ) {
            $this->setLastError( __METHOD__ . ': failed to normalize' );
            return false;
        }
        $thumbName = $file->thumbName( $transformParams );
        $thumbUrl = $file->getThumbUrl( $thumbName );

        if ( $thumbUrl === null ) {
            $this->setLastError( __METHOD__ . ': could not get thumb URL' );
            return false;
        }

        if ( $uploadThumbnailRenderHttpCustomDomain ) {
            $parsedUrl = wfGetUrlUtils()->parse( $thumbUrl );

            if ( !isset( $parsedUrl['path'] ) || $parsedUrl['path'] === '' ) {
                $this->setLastError( __METHOD__ . ": invalid thumb URL: $thumbUrl" );
                return false;
            }

            $thumbUrl = '//' . $uploadThumbnailRenderHttpCustomDomain . $parsedUrl['path'];
        }

        wfDebug( __METHOD__ . ": hitting url {$thumbUrl}" );

        // T203135 We don't wait for the request to complete, as this is mostly fire & forget.
        // Looking at the HTTP status of requests that take less than 1s is a double check.
        $request = MediaWikiServices::getInstance()->getHttpRequestFactory()->create(
            $thumbUrl,
            [ 'method' => 'HEAD', 'followRedirects' => true, 'timeout' => 1 ],
            __METHOD__
        );

        if ( $uploadThumbnailRenderHttpCustomHost ) {
            $request->setHeader( 'Host', $uploadThumbnailRenderHttpCustomHost );
        }

        $status = $request->execute();
        $statusCode = $request->getStatus();
        wfDebug( __METHOD__ . ": received status {$statusCode}" );

        // 400 happens when requesting a size greater or equal than the original
        // TODO use proper error signaling. 400 could mean a number of other things.
        if ( $statusCode === 200 || $statusCode === 301 || $statusCode === 302 || $statusCode === 400 ) {
            return true;
        } elseif ( $statusCode ) {
            $this->setLastError( __METHOD__ . ": incorrect HTTP status $statusCode when hitting $thumbUrl" );
        } elseif ( $status->hasMessage( 'http-timed-out' ) ) {
            // T203135 we ignore timeouts, as it would be inefficient for this job to wait for
            // minutes for the slower thumbnails to complete.
            return true;
        } else {
            $this->setLastError( __METHOD__ . ': HTTP request failure: '
                . Status::wrap( $status )->getWikiText( false, false, 'en' ) );
        }
        return false;
    }

    private function maybeEnqueueNextPage( $transformParams ) {
        if (
            ( $this->params['enqueueNextPage'] ?? false ) &&
            ( $transformParams['page'] ?? 0 ) < ( $this->params['pageLimit'] ?? 0 )
        ) {
            $transformParams['page'] += 1;
            $job = new ThumbnailRenderJob(
                $this->getTitle(),
                [
                    'transformParams' => $transformParams,
                    'enqueueNextPage' => true,
                    'pageLimit' => $this->params['pageLimit']
                ]
            );

            MediaWikiServices::getInstance()->getJobQueueGroup()->lazyPush( [ $job ] );
        }
    }

    /**
     * Whether to retry the job.
     * @return bool
     */
    public function allowRetries() {
        // ThumbnailRenderJob is a warmup for the thumbnails cache,
        // so loosing it is not a problem. Most times the job fails
        // for non-renderable or missing images which will not be fixed
        // by a retry, but will create additional load on the renderer.
        return false;
    }
}