includes/specials/SpecialUploadStash.php

   1 <?php
   2 /**
   3  * Implements Special:UploadStash.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup SpecialPage
  22  * @ingroup Upload
  23  */
  24
  25 /**
  26  * Web access for files temporarily stored by UploadStash.
  27  *
  28  * For example -- files that were uploaded with the UploadWizard extension are stored temporarily
  29  * before committing them to the db. But we want to see their thumbnails and get other information
  30  * about them.
  31  *
  32  * Since this is based on the user's session, in effect this creates a private temporary file area.
  33  * However, the URLs for the files cannot be shared.
  34  */
  35 class SpecialUploadStash extends UnlistedSpecialPage {
  36         // UploadStash
  37         private $stash;
  38
  39         // Since we are directly writing the file to STDOUT,
  40         // we should not be reading in really big files and serving them out.
  41         //
  42         // We also don't want people using this as a file drop, even if they
  43         // share credentials.
  44         //
  45         // This service is really for thumbnails and other such previews while
  46         // uploading.
  47         const MAX_SERVE_BYTES = 1048576; // 1MB
  48
  49         public function __construct() {
  50                 parent::__construct( 'UploadStash', 'upload' );
  51                 try {
  52                         $this->stash = RepoGroup::singleton()->getLocalRepo()->getUploadStash();
  53                 } catch ( UploadStashNotAvailableException $e ) {
  54                 }
  55         }
  56
  57         /**
  58          * Execute page -- can output a file directly or show a listing of them.
  59          *
  60          * @param string $subPage subpage, e.g. in http://example.com/wiki/Special:UploadStash/foo.jpg, the "foo.jpg" part
  61          * @return Boolean: success
  62          */
  63         public function execute( $subPage ) {
  64                 $this->checkPermissions();
  65
  66                 if ( $subPage === null || $subPage === '' ) {
  67                         return $this->showUploads();
  68                 }
  69
  70                 return $this->showUpload( $subPage );
  71         }
  72
  73         /**
  74          * If file available in stash, cats it out to the client as a simple HTTP response.
  75          * n.b. Most sanity checking done in UploadStashLocalFile, so this is straightforward.
  76          *
  77          * @param string $key the key of a particular requested file
  78          * @throws HttpError
  79          * @return bool
  80          */
  81         public function showUpload( $key ) {
  82                 // prevent callers from doing standard HTML output -- we'll take it from here
  83                 $this->getOutput()->disable();
  84
  85                 try {
  86                         $params = $this->parseKey( $key );
  87                         if ( $params['type'] === 'thumb' ) {
  88                                 return $this->outputThumbFromStash( $params['file'], $params['params'] );
  89                         } else {
  90                                 return $this->outputLocalFile( $params['file'] );
  91                         }
  92                 } catch ( UploadStashFileNotFoundException $e ) {
  93                         $code = 404;
  94                         $message = $e->getMessage();
  95                 } catch ( UploadStashZeroLengthFileException $e ) {
  96                         $code = 500;
  97                         $message = $e->getMessage();
  98                 } catch ( UploadStashBadPathException $e ) {
  99                         $code = 500;
 100                         $message = $e->getMessage();
 101                 } catch ( SpecialUploadStashTooLargeException $e ) {
 102                         $code = 500;
 103                         $message = 'Cannot serve a file larger than ' . self::MAX_SERVE_BYTES . ' bytes. ' . $e->getMessage();
 104                 } catch ( Exception $e ) {
 105                         $code = 500;
 106                         $message = $e->getMessage();
 107                 }
 108
 109                 throw new HttpError( $code, $message );
 110         }
 111
 112         /**
 113          * Parse the key passed to the SpecialPage. Returns an array containing
 114          * the associated file object, the type ('file' or 'thumb') and if
 115          * application the transform parameters
 116          *
 117          * @param string $key
 118          * @throws UploadStashBadPathException
 119          * @return array
 120          */
 121         private function parseKey( $key ) {
 122                 $type = strtok( $key, '/' );
 123
 124                 if ( $type !== 'file' && $type !== 'thumb' ) {
 125                         throw new UploadStashBadPathException( "Unknown type '$type'" );
 126                 }
 127                 $fileName = strtok( '/' );
 128                 $thumbPart = strtok( '/' );
 129                 $file = $this->stash->getFile( $fileName );
 130                 if ( $type === 'thumb' ) {
 131                         $srcNamePos = strrpos( $thumbPart, $fileName );
 132                         if ( $srcNamePos === false || $srcNamePos < 1 ) {
 133                                 throw new UploadStashBadPathException( 'Unrecognized thumb name' );
 134                         }
 135                         $paramString = substr( $thumbPart, 0, $srcNamePos - 1 );
 136
 137                         $handler = $file->getHandler();
 138                         if ( $handler ) {
 139                                 $params = $handler->parseParamString( $paramString );
 140
 141                                 return array( 'file' => $file, 'type' => $type, 'params' => $params );
 142                         } else {
 143                                 throw new UploadStashBadPathException( 'No handler found for ' .
 144                                         "mime {$file->getMimeType()} of file {$file->getPath()}" );
 145                         }
 146                 }
 147
 148                 return array( 'file' => $file, 'type' => $type );
 149         }
 150
 151         /**
 152          * Get a thumbnail for file, either generated locally or remotely, and stream it out
 153          *
 154          * @param $file
 155          * @param $params array
 156          *
 157          * @return boolean success
 158          */
 159         private function outputThumbFromStash( $file, $params ) {
 160
 161                 // this global, if it exists, points to a "scaler", as you might find in the Wikimedia Foundation cluster. See outputRemoteScaledThumb()
 162                 // this is part of our horrible NFS-based system, we create a file on a mount point here, but fetch the scaled file from somewhere else that
 163                 // happens to share it over NFS
 164                 global $wgUploadStashScalerBaseUrl;
 165
 166                 $flags = 0;
 167                 if ( $wgUploadStashScalerBaseUrl ) {
 168                         $this->outputRemoteScaledThumb( $file, $params, $flags );
 169                 } else {
 170                         $this->outputLocallyScaledThumb( $file, $params, $flags );
 171                 }
 172         }
 173
 174         /**
 175          * Scale a file (probably with a locally installed imagemagick, or similar) and output it to STDOUT.
 176          * @param $file File
 177          * @param array $params Scaling parameters ( e.g. array( width => '50' ) );
 178          * @param int $flags Scaling flags ( see File:: constants )
 179          * @throws MWException
 180          * @throws UploadStashFileNotFoundException
 181          * @return boolean success
 182          */
 183         private function outputLocallyScaledThumb( $file, $params, $flags ) {
 184
 185                 // n.b. this is stupid, we insist on re-transforming the file every time we are invoked. We rely
 186                 // on HTTP caching to ensure this doesn't happen.
 187
 188                 $flags |= File::RENDER_NOW;
 189
 190                 $thumbnailImage = $file->transform( $params, $flags );
 191                 if ( !$thumbnailImage ) {
 192                         throw new MWException( 'Could not obtain thumbnail' );
 193                 }
 194
 195                 // we should have just generated it locally
 196                 if ( !$thumbnailImage->getStoragePath() ) {
 197                         throw new UploadStashFileNotFoundException( "no local path for scaled item" );
 198                 }
 199
 200                 // now we should construct a File, so we can get mime and other such info in a standard way
 201                 // n.b. mimetype may be different from original (ogx original -> jpeg thumb)
 202                 $thumbFile = new UnregisteredLocalFile( false,
 203                         $this->stash->repo, $thumbnailImage->getStoragePath(), false );
 204                 if ( !$thumbFile ) {
 205                         throw new UploadStashFileNotFoundException( "couldn't create local file object for thumbnail" );
 206                 }
 207
 208                 return $this->outputLocalFile( $thumbFile );
 209         }
 210
 211         /**
 212          * Scale a file with a remote "scaler", as exists on the Wikimedia Foundation cluster, and output it to STDOUT.
 213          * Note: unlike the usual thumbnail process, the web client never sees the cluster URL; we do the whole HTTP transaction to the scaler ourselves
 214          *  and cat the results out.
 215          * Note: We rely on NFS to have propagated the file contents to the scaler. However, we do not rely on the thumbnail being created in NFS and then
 216          *   propagated back to our filesystem. Instead we take the results of the HTTP request instead.
 217          * Note: no caching is being done here, although we are instructing the client to cache it forever.
 218          * @param File $file
 219          * @param array $params Scaling parameters ( e.g. array( width => '50' ) );
 220          * @param $flags Scaling flags ( see File:: constants )
 221          * @throws MWException
 222          * @return boolean success
 223          */
 224         private function outputRemoteScaledThumb( $file, $params, $flags ) {
 225
 226                 // this global probably looks something like 'http://upload.wikimedia.org/wikipedia/test/thumb/temp'
 227                 // do not use trailing slash
 228                 global $wgUploadStashScalerBaseUrl;
 229                 $scalerBaseUrl = $wgUploadStashScalerBaseUrl;
 230
 231                 if ( preg_match( '/^\/\//', $scalerBaseUrl ) ) {
 232                         // this is apparently a protocol-relative URL, which makes no sense in this context,
 233                         // since this is used for communication that's internal to the application.
 234                         // default to http.
 235                         $scalerBaseUrl = wfExpandUrl( $scalerBaseUrl, PROTO_CANONICAL );
 236                 }
 237
 238                 // We need to use generateThumbName() instead of thumbName(), because
 239                 // the suffix needs to match the file name for the remote thumbnailer
 240                 // to work
 241                 $scalerThumbName = $file->generateThumbName( $file->getName(), $params );
 242                 $scalerThumbUrl = $scalerBaseUrl . '/' . $file->getUrlRel() .
 243                         '/' . rawurlencode( $scalerThumbName );
 244
 245                 // make a curl call to the scaler to create a thumbnail
 246                 $httpOptions = array(
 247                         'method' => 'GET',
 248                         'timeout' => 'default'
 249                 );
 250                 $req = MWHttpRequest::factory( $scalerThumbUrl, $httpOptions );
 251                 $status = $req->execute();
 252                 if ( !$status->isOK() ) {
 253                         $errors = $status->getErrorsArray();
 254                         $errorStr = "Fetching thumbnail failed: " . print_r( $errors, 1 );
 255                         $errorStr .= "\nurl = $scalerThumbUrl\n";
 256                         throw new MWException( $errorStr );
 257                 }
 258                 $contentType = $req->getResponseHeader( "content-type" );
 259                 if ( !$contentType ) {
 260                         throw new MWException( "Missing content-type header" );
 261                 }
 262
 263                 return $this->outputContents( $req->getContent(), $contentType );
 264         }
 265
 266         /**
 267          * Output HTTP response for file
 268          * Side effect: writes HTTP response to STDOUT.
 269          *
 270          * @param $file File object with a local path (e.g. UnregisteredLocalFile, LocalFile. Oddly these don't share an ancestor!)
 271          * @throws SpecialUploadStashTooLargeException
 272          * @return bool
 273          */
 274         private function outputLocalFile( File $file ) {
 275                 if ( $file->getSize() > self::MAX_SERVE_BYTES ) {
 276                         throw new SpecialUploadStashTooLargeException();
 277                 }
 278
 279                 return $file->getRepo()->streamFile( $file->getPath(),
 280                         array( 'Content-Transfer-Encoding: binary',
 281                                 'Expires: Sun, 17-Jan-2038 19:14:07 GMT' )
 282                 );
 283         }
 284
 285         /**
 286          * Output HTTP response of raw content
 287          * Side effect: writes HTTP response to STDOUT.
 288          * @param string $content content
 289          * @param string $contentType mime type
 290          * @throws SpecialUploadStashTooLargeException
 291          * @return bool
 292          */
 293         private function outputContents( $content, $contentType ) {
 294                 $size = strlen( $content );
 295                 if ( $size > self::MAX_SERVE_BYTES ) {
 296                         throw new SpecialUploadStashTooLargeException();
 297                 }
 298                 self::outputFileHeaders( $contentType, $size );
 299                 print $content;
 300
 301                 return true;
 302         }
 303
 304         /**
 305          * Output headers for streaming
 306          * XXX unsure about encoding as binary; if we received from HTTP perhaps we should use that encoding, concatted with semicolon to mimeType as it usually is.
 307          * Side effect: preps PHP to write headers to STDOUT.
 308          * @param string $contentType String suitable for content-type header
 309          * @param string $size Length in bytes
 310          */
 311         private static function outputFileHeaders( $contentType, $size ) {
 312                 header( "Content-Type: $contentType", true );
 313                 header( 'Content-Transfer-Encoding: binary', true );
 314                 header( 'Expires: Sun, 17-Jan-2038 19:14:07 GMT', true );
 315                 // Bug 53032 - It shouldn't be a problem here, but let's be safe and not cache
 316                 header( 'Cache-Control: private' );
 317                 header( "Content-Length: $size", true );
 318         }
 319
 320         /**
 321          * Static callback for the HTMLForm in showUploads, to process
 322          * Note the stash has to be recreated since this is being called in a static context.
 323          * This works, because there really is only one stash per logged-in user, despite appearances.
 324          *
 325          * @param array $formData
 326          * @return Status
 327          */
 328         public static function tryClearStashedUploads( $formData ) {
 329                 if ( isset( $formData['Clear'] ) ) {
 330                         $stash = RepoGroup::singleton()->getLocalRepo()->getUploadStash();
 331                         wfDebug( "stash has: " . print_r( $stash->listFiles(), true ) );
 332
 333                         if ( !$stash->clear() ) {
 334                                 return Status::newFatal( 'uploadstash-errclear' );
 335                         }
 336                 }
 337
 338                 return Status::newGood();
 339         }
 340
 341         /**
 342          * Default action when we don't have a subpage -- just show links to the uploads we have,
 343          * Also show a button to clear stashed files
 344          * @return bool
 345          */
 346         private function showUploads() {
 347                 // sets the title, etc.
 348                 $this->setHeaders();
 349                 $this->outputHeader();
 350
 351                 // create the form, which will also be used to execute a callback to process incoming form data
 352                 // this design is extremely dubious, but supposedly HTMLForm is our standard now?
 353
 354                 $context = new DerivativeContext( $this->getContext() );
 355                 $context->setTitle( $this->getPageTitle() ); // Remove subpage
 356                 $form = new HTMLForm( array(
 357                         'Clear' => array(
 358                                 'type' => 'hidden',
 359                                 'default' => true,
 360                                 'name' => 'clear',
 361                         )
 362                 ), $context, 'clearStashedUploads' );
 363                 $form->setSubmitCallback( array( __CLASS__, 'tryClearStashedUploads' ) );
 364                 $form->setSubmitTextMsg( 'uploadstash-clear' );
 365
 366                 $form->prepareForm();
 367                 $formResult = $form->tryAuthorizedSubmit();
 368
 369                 // show the files + form, if there are any, or just say there are none
 370                 $refreshHtml = Html::element( 'a',
 371                         array( 'href' => $this->getPageTitle()->getLocalURL() ),
 372                         $this->msg( 'uploadstash-refresh' )->text() );
 373                 $files = $this->stash->listFiles();
 374                 if ( $files && count( $files ) ) {
 375                         sort( $files );
 376                         $fileListItemsHtml = '';
 377                         foreach ( $files as $file ) {
 378                                 // TODO: Use Linker::link or even construct the list in plain wikitext
 379                                 $fileListItemsHtml .= Html::rawElement( 'li', array(),
 380                                         Html::element( 'a', array( 'href' =>
 381                                                 $this->getPageTitle( "file/$file" )->getLocalURL() ), $file )
 382                                 );
 383                         }
 384                         $this->getOutput()->addHtml( Html::rawElement( 'ul', array(), $fileListItemsHtml ) );
 385                         $form->displayForm( $formResult );
 386                         $this->getOutput()->addHtml( Html::rawElement( 'p', array(), $refreshHtml ) );
 387                 } else {
 388                         $this->getOutput()->addHtml( Html::rawElement( 'p', array(),
 389                                 Html::element( 'span', array(), $this->msg( 'uploadstash-nofiles' )->text() )
 390                                 . ' '
 391                                 . $refreshHtml
 392                         ) );
 393                 }
 394
 395                 return true;
 396         }
 397 }
 398
 399 class SpecialUploadStashTooLargeException extends MWException {
 400 }
 401