Merge ".mailmap: Correct two contributor names"

[mediawiki.git] / includes / filerepo / ThumbnailEntryPoint.php

<?php
/**
 * Entry point implementation for retrieving media thumbnails, created by a MediaHandler
 * subclass or proxy request if FileRepo::getThumbProxyUrl is configured.
 *
 * This also supports resizing an image on-demand, if it isn't found in the
 * configured FileBackend storage.
 *
 * @see /thumb.php The web entry point.
 *
 * 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
 * @ingroup entrypoint
 * @ingroup Media
 */

namespace MediaWiki\FileRepo;

use Exception;
use File;
use InvalidArgumentException;
use MediaTransformError;
use MediaTransformInvalidParametersException;
use MediaTransformOutput;
use MediaWiki\Logger\LoggerFactory;
use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiEntryPoint;
use MediaWiki\MediaWikiServices;
use MediaWiki\Message\Message;
use MediaWiki\Permissions\PermissionStatus;
use MediaWiki\PoolCounter\PoolCounterWorkViaCallback;
use MediaWiki\Profiler\ProfilingContext;
use MediaWiki\Request\HeaderCallback;
use MediaWiki\Status\Status;
use MediaWiki\Title\Title;
use RepoGroup;
use UnregisteredLocalFile;
use Wikimedia\AtEase\AtEase;
use Wikimedia\Message\MessageSpecifier;

class ThumbnailEntryPoint extends MediaWikiEntryPoint {

        /** @var string[] */
        private $varyHeader = [];

        /**
         * Main entry point
         */
        public function execute() {
                global $wgTrivialMimeDetection;

                ProfilingContext::singleton()->init(
                        MW_ENTRY_POINT,
                        'stream'
                );

                // Don't use fancy MIME detection, just check the file extension for jpg/gif/png.
                // NOTE: This only works as long as to StreamFile::contentTypeFromPath
                //       get this setting from global state. When StreamFile gets refactored,
                //       we need to find a better way.
                $wgTrivialMimeDetection = true;

                $this->handleRequest();
        }

        protected function doPrepareForOutput() {
                // No-op.
                // Do not call parent::doPrepareForOutput() to avoid
                // commitMainTransaction() getting called.
        }

        protected function handleRequest() {
                $this->streamThumb( $this->getRequest()->getQueryValuesOnly() );
        }

        private function getRepoGroup(): RepoGroup {
                return $this->getServiceContainer()->getRepoGroup();
        }

        /**
         * Stream a thumbnail specified by parameters
         *
         * @param array $params List of thumbnailing parameters. In addition to parameters
         *  passed to the MediaHandler, this may also includes the keys:
         *   f (for filename), archived (if archived file), temp (if temp file),
         *   w (alias for width), p (alias for page), r (ignored; historical),
         *   rel404 (path for render on 404 to verify hash path correct),
         *   thumbName (thumbnail name to potentially extract more parameters from
         *   e.g. 'lossy-page1-120px-Foo.tiff' would add page, lossy and width
         *   to the parameters)
         *
         * @return void
         */
        protected function streamThumb( array $params ) {
                $headers = []; // HTTP headers to send

                $fileName = $params['f'] ?? '';

                // Backwards compatibility parameters
                if ( isset( $params['w'] ) ) {
                        $params['width'] = $params['w'];
                        unset( $params['w'] );
                }
                if ( isset( $params['width'] ) && substr( $params['width'], -2 ) == 'px' ) {
                        // strip the px (pixel) suffix, if found
                        $params['width'] = substr( $params['width'], 0, -2 );
                }
                if ( isset( $params['p'] ) ) {
                        $params['page'] = $params['p'];
                }

                // Is this a thumb of an archived file?
                $isOld = ( isset( $params['archived'] ) && $params['archived'] );
                unset( $params['archived'] ); // handlers don't care

                // Is this a thumb of a temp file?
                $isTemp = ( isset( $params['temp'] ) && $params['temp'] );
                unset( $params['temp'] ); // handlers don't care

                $services = $this->getServiceContainer();

                // Some basic input validation
                $fileName = strtr( $fileName, '\\/', '__' );
                $localRepo = $services->getRepoGroup()->getLocalRepo();
                $archiveTimestamp = null;

                // Actually fetch the image. Method depends on whether it is archived or not.
                if ( $isTemp ) {
                        $repo = $localRepo->getTempRepo();
                        $img = new UnregisteredLocalFile( false, $repo,
                                # Temp files are hashed based on the name without the timestamp.
                                # The thumbnails will be hashed based on the entire name however.
                                # @todo fix this convention to actually be reasonable.
                                $repo->getZonePath( 'public' ) . '/' . $repo->getTempHashPath( $fileName ) . $fileName
                        );
                } elseif ( $isOld ) {
                        // Format is <timestamp>!<name>
                        $bits = explode( '!', $fileName, 2 );
                        if ( count( $bits ) != 2 ) {
                                $this->thumbError( 404, $this->getContext()->msg( 'badtitletext' )->parse() );
                                return;
                        }
                        $archiveTimestamp = $bits[0];
                        $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
                        if ( !$title ) {
                                $this->thumbError( 404, $this->getContext()->msg( 'badtitletext' )->parse() );
                                return;
                        }
                        $img = $localRepo->newFromArchiveName( $title, $fileName );
                } else {
                        $img = $localRepo->newFile( $fileName );
                }

                // Check the source file title
                if ( !$img ) {
                        $this->thumbError( 404, $this->getContext()->msg( 'badtitletext' )->parse() );
                        return;
                }

                // Check permissions if there are read restrictions
                if ( $this->maybeDenyAccess( $img ) ) {
                        return;
                }

                // Check if the file is hidden
                if ( $img->isDeleted( File::DELETED_FILE ) ) {
                        $this->thumbErrorText( 404, "The source file '$fileName' does not exist." );
                        return;
                }

                // Do rendering parameters extraction from thumbnail name.
                if ( isset( $params['thumbName'] ) ) {
                        $params = $this->extractThumbParams( $img, $params );
                }
                if ( $params == null ) {
                        $this->thumbErrorText( 400, 'The specified thumbnail parameters are not recognized.' );
                        return;
                }

                // Check the source file storage path
                if ( !$img->exists() ) {
                        $redirected = $this->maybeDoRedirect(
                                $img,
                                $params,
                                $isTemp,
                                $isOld,
                                $archiveTimestamp
                        );

                        if ( !$redirected ) {
                                // If it's not a redirect that has a target as a local file, give 404.
                                $this->thumbErrorText(
                                        404,
                                        "The source file '$fileName' does not exist."
                                );
                        }

                        $this->applyVaryHeader();

                        return;
                } elseif ( $img->getPath() === false ) {
                        $this->thumbErrorText( 400, "The source file '$fileName' is not locally accessible." );
                        return;
                }

                // Check IMS against the source file
                // This means that clients can keep a cached copy even after it has been deleted on the server
                if ( $this->maybeNotModified( $img ) ) {
                        return;
                }

                $rel404 = $params['rel404'] ?? null;
                unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
                unset( $params['f'] ); // We're done with 'f' parameter.
                unset( $params['rel404'] ); // moved to $rel404

                // Get the normalized thumbnail name from the parameters...
                try {
                        $thumbName = $img->thumbName( $params );
                        if ( !strlen( $thumbName ?? '' ) ) { // invalid params?
                                throw new MediaTransformInvalidParametersException(
                                        'Empty return from File::thumbName'
                                );
                        }
                        $thumbName2 = $img->thumbName( $params, File::THUMB_FULL_NAME ); // b/c; "long" style
                } catch ( MediaTransformInvalidParametersException $e ) {
                        $this->thumbErrorText(
                                400,
                                'The specified thumbnail parameters are not valid: ' . $e->getMessage()
                        );

                        return;
                }

                // For 404 handled thumbnails, we only use the base name of the URI
                // for the thumb params and the parent directory for the source file name.
                // Check that the zone relative path matches up so CDN caches won't pick
                // up thumbs that would not be purged on source file deletion (T36231).
                if ( $rel404 !== null ) { // thumbnail was handled via 404
                        if (
                                $this->maybeNormalizeRel404Path(
                                        $img,
                                        $rel404,
                                        $thumbName,
                                        $thumbName2
                                )
                        ) {
                                $this->applyVaryHeader();

                                return;
                        }
                }

                $dispositionType = isset( $params['download'] ) ? 'attachment' : 'inline';

                // Suggest a good name for users downloading this thumbnail
                $headers[] =
                        'Content-Disposition: ' . $img->getThumbDisposition( $thumbName, $dispositionType );

                $this->applyVaryHeader();

                // Stream the file if it exists already...
                $thumbPath = $img->getThumbPath( $thumbName );

                if ( $this->maybeStreamExistingThumbnail( $img, $thumbName, $thumbPath, $headers ) ) {
                        return;
                }

                if ( $this->maybeEnforceRateLimits( $img, $params ) ) {
                        return;
                }

                $thumbProxyUrl = $img->getRepo()->getThumbProxyUrl();

                if ( strlen( $thumbProxyUrl ?? '' ) ) {
                        $this->proxyThumbnailRequest( $img, $thumbName );
                        // No local fallback when in proxy mode
                        return;
                } else {
                        // Generate the thumbnail locally
                        [ $thumb, $errorMsg, $errorCode ] = $this->generateThumbnail( $img, $params, $thumbName, $thumbPath );
                }

                $this->prepareForOutput();

                if ( !$thumb ) {
                        $errorMsg ??= 'unknown error'; // Just to make Phan happy, shouldn't happen.
                        $this->thumbError( $errorCode, $errorMsg, null, [ 'file' => $thumbName, 'path' => $thumbPath ] );
                } else {
                        // Stream the file if there were no errors
                        /** @var MediaTransformOutput $thumb */
                        '@phan-var MediaTransformOutput $thumb';
                        $status = $thumb->streamFileWithStatus( $headers );
                        if ( !$status->isOK() ) {
                                $this->thumbError( 500, 'Could not stream the file', $status->getWikiText( false, false, 'en' ), [
                                        'file' => $thumbName, 'path' => $thumbPath,
                                        'error' => $status->getWikiText( false, false, 'en' ) ] );
                        }
                }
        }

        /**
         * Proxies thumbnail request to a service that handles thumbnailing
         *
         * @param File $img
         * @param string $thumbName
         */
        private function proxyThumbnailRequest( $img, $thumbName ) {
                $thumbProxyUrl = $img->getRepo()->getThumbProxyUrl();

                // Instead of generating the thumbnail ourselves, we proxy the request to another service
                $thumbProxiedUrl = $thumbProxyUrl . $img->getThumbRel( $thumbName );

                $req = MediaWikiServices::getInstance()->getHttpRequestFactory()->create( $thumbProxiedUrl, [], __METHOD__ );
                $secret = $img->getRepo()->getThumbProxySecret();

                // Pass a secret key shared with the proxied service if any
                if ( strlen( $secret ?? '' ) ) {
                        $req->setHeader( 'X-Swift-Secret', $secret );
                }

                // Send request to proxied service
                $req->execute();

                HeaderCallback::warnIfHeadersSent();

                // Simply serve the response from the proxied service as-is
                $this->header( 'HTTP/1.1 ' . $req->getStatus() );

                $headers = $req->getResponseHeaders();

                foreach ( $headers as $key => $values ) {
                        foreach ( $values as $value ) {
                                $this->header( $key . ': ' . $value, false );
                        }
                }

                $this->print( $req->getContent() );
        }

        /**
         * Actually try to generate a new thumbnail
         *
         * @param File $file
         * @param array $params
         * @param string $thumbName
         * @param string $thumbPath
         * @return array [ $thumb, $errorHtml, $errorCode ], which will be
         *         either [MediaTransformOutput, null, int] or [null, string, int].
         * @phan-return array{0:?MediaTransformOutput, 1:?string, 2:int}
         */
        protected function generateThumbnail( File $file, array $params, $thumbName, $thumbPath ) {
                $attemptFailureEpoch = $this->getConfig( MainConfigNames::AttemptFailureEpoch );

                $services = MediaWikiServices::getInstance()->getObjectCacheFactory();

                $cache = $services->getLocalClusterInstance();
                $key = $cache->makeKey(
                        'attempt-failures',
                        $attemptFailureEpoch,
                        $file->getRepo()->getName(),
                        $file->getSha1(),
                        md5( $thumbName )
                );

                // Check if this file keeps failing to render
                if ( $cache->get( $key ) >= 4 ) {
                        return [
                                null,
                                $this->getContext()->msg( 'thumbnail_image-failure-limit', 4 )->escaped(),
                                500,
                        ];
                }

                $done = false;
                // Record failures on PHP fatals in addition to caching exceptions
                register_shutdown_function( static function () use ( $cache, &$done, $key ) {
                        if ( !$done ) { // transform() gave a fatal
                                // Randomize TTL to reduce stampedes
                                $cache->incrWithInit( $key, $cache::TTL_HOUR + mt_rand( 0, 300 ) );
                        }
                } );

                /** @var MediaTransformOutput $thumb|null */
                $thumb = null;
                $errorHtml = null;
                '@phan-var MediaTransformOutput $thumb|false';

                // guard thumbnail rendering with PoolCounter to avoid stampedes
                // expensive files use a separate PoolCounter config so it is possible
                // to set up a global limit on them
                if ( $file->isExpensiveToThumbnail() ) {
                        $poolCounterType = 'FileRenderExpensive';
                } else {
                        $poolCounterType = 'FileRender';
                }

                // Thumbnail isn't already there, so create the new thumbnail...
                try {
                        $work = new PoolCounterWorkViaCallback( $poolCounterType, sha1( $file->getName() ),
                                [
                                        'doWork' => static function () use ( $file, $params ) {
                                                return $file->transform( $params, File::RENDER_NOW );
                                        },
                                        'doCachedWork' => static function () use ( $file, $params, $thumbPath ) {
                                                // If the worker that finished made this thumbnail then use it.
                                                // Otherwise, it probably made a different thumbnail for this file.
                                                return $file->getRepo()->fileExists( $thumbPath )
                                                        ? $file->transform( $params, File::RENDER_NOW )
                                                        : false; // retry once more in exclusive mode
                                        },
                                        'error' => function ( Status $status ) {
                                                return $this->getContext()->msg( 'generic-pool-error' )->parse() . '<hr>' . $status->getHTML();
                                        }
                                ]
                        );
                        $result = $work->execute();
                        if ( $result instanceof MediaTransformOutput ) {
                                $thumb = $result;
                        } elseif ( is_string( $result ) ) { // error
                                $errorHtml = $result;
                        }
                } catch ( Exception $e ) {
                        // Tried to select a page on a non-paged file?
                }

                /** @noinspection PhpUnusedLocalVariableInspection */
                $done = true; // no PHP fatal occurred

                if ( !$thumb || $thumb->isError() ) {
                        // Randomize TTL to reduce stampedes
                        $cache->incrWithInit( $key, $cache::TTL_HOUR + mt_rand( 0, 300 ) );
                }

                // Check for thumbnail generation errors...
                $msg = $this->getContext()->msg( 'thumbnail_error' );
                $errorCode = null;

                if ( !$thumb ) {
                        $errorHtml = $errorHtml ?: $msg->rawParams( 'File::transform() returned false' );
                        $errorCode = 500;
                } elseif ( $thumb instanceof MediaTransformError ) {
                        $errorHtml = $thumb->getMsg();
                        $errorCode = $thumb->getHttpStatusCode();
                } elseif ( !$thumb->hasFile() ) {
                        $errorHtml = $msg->rawParams( 'No path supplied in thumbnail object' );
                        $errorCode = 500;
                } elseif ( $thumb->fileIsSource() ) {
                        $errorHtml = $msg
                                ->rawParams( 'Image was not scaled, is the requested width bigger than the source?' );
                        $errorCode = 400;
                }

                if ( $errorCode && $errorHtml ) {
                        if ( $errorHtml instanceof MessageSpecifier &&
                                $errorHtml->getKey() === 'thumbnail_image-failure-limit'
                        ) {
                                $errorCode = 429;
                        }

                        if ( $errorHtml instanceof Message ) {
                                $errorHtml = $errorHtml->escaped();
                        }

                        return [ null, $errorHtml, $errorCode ];
                }

                return [ $thumb, null, 200 ];
        }

        /**
         * Convert a thumbnail name (122px-foo.png) to parameters, using
         * file handler.
         *
         * @param File $file File object for file in question
         * @param array $params Array of parameters so far
         * @return array|null Parameters array with more parameters, or null
         */
        private function extractThumbParams( $file, $params ) {
                if ( !isset( $params['thumbName'] ) ) {
                        throw new InvalidArgumentException( "No thumbnail name passed to extractThumbParams" );
                }

                $thumbname = $params['thumbName'];
                unset( $params['thumbName'] );

                // FIXME: Files in the temp zone don't set a MIME type, which means
                // they don't have a handler. Which means we can't parse the param
                // string. However, not a big issue as what good is a param string
                // if you have no handler to make use of the param string and
                // actually generate the thumbnail.
                $handler = $file->getHandler();

                // Based on UploadStash::parseKey
                $fileNamePos = strrpos( $thumbname, $params['f'] );
                if ( $fileNamePos === false ) {
                        // Maybe using a short filename? (see FileRepo::nameForThumb)
                        $fileNamePos = strrpos( $thumbname, 'thumbnail' );
                }

                if ( $handler && $fileNamePos !== false ) {
                        $paramString = substr( $thumbname, 0, $fileNamePos - 1 );
                        $extraParams = $handler->parseParamString( $paramString );
                        if ( $extraParams !== false ) {
                                return $params + $extraParams;
                        }
                }

                // As a last ditch fallback, use the traditional common parameters
                if ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
                        [ /* all */, /* pagefull */, $pagenum, $size ] = $matches;
                        $params['width'] = $size;
                        if ( $pagenum ) {
                                $params['page'] = $pagenum;
                        }
                        return $params; // valid thumbnail URL
                }
                return null;
        }

        /**
         * Output a thumbnail generation error message
         *
         * @param int $status
         * @param string $msgText Plain text (will be html escaped)
         * @return void
         */
        protected function thumbErrorText( $status, $msgText ) {
                $this->thumbError( $status, htmlspecialchars( $msgText, ENT_NOQUOTES ) );
        }

        /**
         * Output a thumbnail generation error message
         *
         * @param int $status
         * @param string $msgHtml HTML
         * @param string|null $msgText Short error description, for internal logging. Defaults to $msgHtml.
         *   Only used for HTTP 500 errors.
         * @param array $context Error context, for internal logging. Only used for HTTP 500 errors.
         * @return void
         */
        protected function thumbError( $status, $msgHtml, $msgText = null, $context = [] ) {
                $showHostnames = $this->getConfig( MainConfigNames::ShowHostnames );

                HeaderCallback::warnIfHeadersSent();

                if ( $this->getResponse()->headersSent() ) {
                        LoggerFactory::getInstance( 'thumbnail' )->error(
                                'Error after output had been started. Output may be corrupt or truncated. ' .
                                'Original error: ' . ( $msgText ?: $msgHtml ) . " (Status $status)",
                                $context
                        );
                        return;
                }

                $this->header( 'Cache-Control: no-cache' );
                $this->header( 'Content-Type: text/html; charset=utf-8' );
                if ( $status == 400 || $status == 404 || $status == 429 ) {
                        $this->status( $status );
                } elseif ( $status == 403 ) {
                        $this->status( 403 );
                        $this->header( 'Vary: Cookie' );
                } else {
                        LoggerFactory::getInstance( 'thumbnail' )->error( $msgText ?: $msgHtml, $context );
                        $this->status( 500 );
                }
                if ( $showHostnames ) {
                        $this->header( 'X-MW-Thumbnail-Renderer: ' . wfHostname() );
                        $url = htmlspecialchars(
                                $this->getServerInfo( 'REQUEST_URI' ) ?? '',
                                ENT_NOQUOTES
                        );
                        $hostname = htmlspecialchars( wfHostname(), ENT_NOQUOTES );
                        $debug = "<!-- $url -->\n<!-- $hostname -->\n";
                } else {
                        $debug = '';
                }
                $content = <<<EOT
<!DOCTYPE html>
<html><head>
<meta charset="UTF-8" />
<meta name="color-scheme" content="light dark" />
<title>Error generating thumbnail</title>
</head>
<body>
<h1>Error generating thumbnail</h1>
<p>
$msgHtml
</p>
$debug
</body>
</html>

EOT;
                $this->header( 'Content-Length: ' . strlen( $content ) );
                $this->print( $content );
        }

        /**
         * @return bool true if redirected
         */
        private function maybeDoRedirect(
                File $img,
                array $params,
                bool $isTemp,
                bool $isOld,
                ?string $archiveTimestamp
        ): bool {
                $varyOnXFP = $this->getConfig( MainConfigNames::VaryOnXFP );

                $redirectedLocation = false;
                if ( !$isTemp ) {
                        // Check for file redirect
                        // Since redirects are associated with pages, not versions of files,
                        // we look for the most current version to see if its a redirect.
                        $localRepo = $this->getRepoGroup()->getLocalRepo();
                        $possRedirFile = $localRepo->findFile( $img->getName() );
                        if ( $possRedirFile && $possRedirFile->getRedirected() !== null ) {
                                $redirTarget = $possRedirFile->getName();
                                $targetFile = $localRepo->newFile(
                                        Title::makeTitleSafe(
                                                NS_FILE,
                                                $redirTarget
                                        )
                                );
                                if ( $targetFile->exists() ) {
                                        $newThumbName = $targetFile->thumbName( $params );
                                        if ( $isOld ) {
                                                $newThumbUrl = $targetFile->getArchiveThumbUrl(
                                                        $archiveTimestamp . '!' . $targetFile->getName(),
                                                        $newThumbName
                                                );
                                        } else {
                                                $newThumbUrl = $targetFile->getThumbUrl( $newThumbName );
                                        }
                                        $redirectedLocation = $this->getUrlUtils()->expand(
                                                $newThumbUrl,
                                                PROTO_CURRENT
                                        ) ?? false;
                                }
                        }
                }

                if ( $redirectedLocation ) {
                        // File has been moved. Give redirect.
                        $response = $this->getResponse();
                        $response->statusHeader( 302 );
                        $response->header( 'Location: ' . $redirectedLocation );
                        $response->header(
                                'Expires: ' . gmdate( 'D, d M Y H:i:s', time() + 12 * 3600 ) . ' GMT'
                        );
                        if ( $varyOnXFP ) {
                                $this->vary( 'X-Forwarded-Proto' );
                        }
                        $response->header( 'Content-Length: 0' );

                        return true;
                }

                return false;
        }

        private function vary( $header ) {
                $this->varyHeader[] = $header;
        }

        private function applyVaryHeader() {
                if ( count( $this->varyHeader ) ) {
                        $this->header( 'Vary: ' . implode( ', ', $this->varyHeader ) );
                }
        }

        /**
         * @return bool true if access was denied
         */
        private function maybeDenyAccess( File $img ): bool {
                $permissionLookup = $this->getServiceContainer()->getGroupPermissionsLookup();

                if ( !$permissionLookup->groupHasPermission( '*', 'read' ) ) {
                        $authority = $this->getContext()->getAuthority();
                        $imgTitle = $img->getTitle();

                        if ( !$imgTitle || !$authority->authorizeRead( 'read', $imgTitle ) ) {
                                $this->thumbErrorText(
                                        403,
                                        'Access denied. You do not have permission to access the source file.'
                                );

                                return true;
                        }
                        $this->header( 'Cache-Control: private' );
                        $this->vary( 'Cookie' );
                }

                return false;
        }

        /**
         * @return bool true if not modified
         */
        private function maybeNotModified( File $img ): bool {
                if ( $this->getServerInfo( 'HTTP_IF_MODIFIED_SINCE', '' ) !== '' ) {
                        // Fix IE brokenness
                        $imsString = preg_replace(
                                '/;.*$/',
                                '',
                                $this->getServerInfo( 'HTTP_IF_MODIFIED_SINCE' ) ?? ''
                        );

                        // Calculate time
                        AtEase::suppressWarnings();
                        $imsUnix = strtotime( $imsString );
                        AtEase::restoreWarnings();
                        if ( wfTimestamp( TS_UNIX, $img->getTimestamp() ) <= $imsUnix ) {
                                $this->status( 304 );

                                return true;
                        }
                }

                return false;
        }

        /**
         * @param File $img
         * @param string $rel404
         * @param string|false $thumbName
         * @param string|false $thumbName2
         *
         * @return bool
         */
        private function maybeNormalizeRel404Path(
                File $img,
                string $rel404,
                $thumbName,
                $thumbName2
        ): bool {
                $varyOnXFP = $this->getConfig( MainConfigNames::VaryOnXFP );

                if ( rawurldecode( $rel404 ) === $img->getThumbRel( $thumbName ) ) {
                        // Request for the canonical thumbnail name
                        return false;
                } elseif ( rawurldecode( $rel404 ) === $img->getThumbRel( $thumbName2 ) ) {
                        // Request for the "long" thumbnail name; redirect to canonical name
                        $target = $this->getUrlUtils()->expand(
                                $img->getThumbUrl( $thumbName ),
                                PROTO_CURRENT
                        ) ?? false;
                        $this->status( 301 );
                        $this->header( 'Location: ' . $target );
                        $this->header(
                                'Expires: ' . gmdate( 'D, d M Y H:i:s', time() + 7 * 86400 ) . ' GMT'
                        );

                        if ( $varyOnXFP ) {
                                $this->vary( 'X-Forwarded-Proto' );
                        }

                        return true;
                } else {
                        $this->thumbErrorText(
                                404,
                                "The given path of the specified thumbnail is incorrect; expected '" .
                                $img->getThumbRel( $thumbName ) . "' but got '" . rawurldecode( $rel404 ) . "'."
                        );

                        return true;
                }
        }

        /**
         * @return bool true if we attempted to stream the thumb, even if it failed.
         */
        private function maybeStreamExistingThumbnail(
                File $img,
                string $thumbName,
                string $thumbPath,
                array $headers
        ): bool {
                $stats = $this->getServiceContainer()->getStatsFactory();

                if ( $img->getRepo()->fileExists( $thumbPath ) ) {
                        $starttime = microtime( true );
                        $status = $img->getRepo()->streamFileWithStatus(
                                $thumbPath,
                                $headers
                        );
                        $streamtime = microtime( true ) - $starttime;

                        if ( $status->isOK() ) {
                                $stats->getTiming( 'media_thumbnail_stream_seconds' )
                                        ->copyToStatsdAt( 'media.thumbnail.stream' )
                                        ->observe( $streamtime * 1000 );
                        } else {
                                $this->thumbError(
                                        500,
                                        'Could not stream the file',
                                        $status->getWikiText( false, false, 'en' ),
                                        [
                                                'file' => $thumbName,
                                                'path' => $thumbPath,
                                                'error' => $status->getWikiText( false, false, 'en' ),
                                        ]
                                );
                        }

                        return true;
                }

                return false;
        }

        private function maybeEnforceRateLimits( File $img, array $params ) {
                $authority = $this->getContext()->getAuthority();
                $status = PermissionStatus::newEmpty();

                if ( !wfThumbIsStandard( $img, $params )
                        && !$authority->authorizeAction( 'renderfile-nonstandard', $status )
                ) {
                        $statusFormatter = $this->getServiceContainer()->getFormatterFactory()
                                ->getStatusFormatter( $this->getContext() );

                        $this->thumbError( 429, $statusFormatter->getHTML( $status ) );
                        return true;
                } elseif ( !$authority->authorizeAction( 'renderfile', $status ) ) {
                        $statusFormatter = $this->getServiceContainer()->getFormatterFactory()
                                ->getStatusFormatter( $this->getContext() );

                        $this->thumbError( 429, $statusFormatter->getHTML( $status ) );
                        return true;
                }

                return false;
        }

}