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         /**
  40          * Since we are directly writing the file to STDOUT,
  41          * we should not be reading in really big files and serving them out.
  42          *
  43          * We also don't want people using this as a file drop, even if they
  44          * share credentials.
  45          *
  46          * This service is really for thumbnails and other such previews while
  47          * uploading.
  48          */
  49         const MAX_SERVE_BYTES = 1048576; // 1MB
  50
  51         public function __construct() {
  52                 parent::__construct( 'UploadStash', 'upload' );
  53         }
  54
  55         /**
  56          * Execute page -- can output a file directly or show a listing of them.
  57          *
  58          * @param string $subPage Subpage, e.g. in
  59          *   http://example.com/wiki/Special:UploadStash/foo.jpg, the "foo.jpg" part
  60          * @return bool Success
  61          */
  62         public function execute( $subPage ) {
  63                 $this->useTransactionalTimeLimit();
  64
  65                 $this->stash = RepoGroup::singleton()->getLocalRepo()->getUploadStash( $this->getUser() );
  66                 $this->checkPermissions();
  67
  68                 if ( $subPage === null || $subPage === '' ) {
  69                         return $this->showUploads();
  70                 }
  71
  72                 return $this->showUpload( $subPage );
  73         }
  74
  75         /**
  76          * If file available in stash, cats it out to the client as a simple HTTP response.
  77          * n.b. Most sanity checking done in UploadStashLocalFile, so this is straightforward.
  78          *
  79          * @param string $key The key of a particular requested file
  80          * @throws HttpError
  81          * @return bool
  82          */
  83         public function showUpload( $key ) {
  84                 // prevent callers from doing standard HTML output -- we'll take it from here
  85                 $this->getOutput()->disable();
  86
  87                 try {
  88                         $params = $this->parseKey( $key );
  89                         if ( $params['type'] === 'thumb' ) {
  90                                 return $this->outputThumbFromStash( $params['file'], $params['params'] );
  91                         } else {
  92                                 return $this->outputLocalFile( $params['file'] );
  93                         }
  94                 } catch ( UploadStashFileNotFoundException $e ) {
  95                         $code = 404;
  96                         $message = $e->getMessage();
  97                 } catch ( UploadStashZeroLengthFileException $e ) {
  98                         $code = 500;
  99                         $message = $e->getMessage();
 100                 } catch ( UploadStashBadPathException $e ) {
 101                         $code = 500;
 102                         $message = $e->getMessage();
 103                 } catch ( SpecialUploadStashTooLargeException $e ) {
 104                         $code = 500;
 105                         $message = 'Cannot serve a file larger than ' . self::MAX_SERVE_BYTES .
 106                                 ' bytes. ' . $e->getMessage();
 107                 } catch ( Exception $e ) {
 108                         $code = 500;
 109                         $message = $e->getMessage();
 110                 }
 111
 112                 throw new HttpError( $code, $message );
 113         }
 114
 115         /**
 116          * Parse the key passed to the SpecialPage. Returns an array containing
 117          * the associated file object, the type ('file' or 'thumb') and if
 118          * application the transform parameters
 119          *
 120          * @param string $key
 121          * @throws UploadStashBadPathException
 122          * @return array
 123          */
 124         private function parseKey( $key ) {
 125                 $type = strtok( $key, '/' );
 126
 127                 if ( $type !== 'file' && $type !== 'thumb' ) {
 128                         throw new UploadStashBadPathException( "Unknown type '$type'" );
 129                 }
 130                 $fileName = strtok( '/' );
 131                 $thumbPart = strtok( '/' );
 132                 $file = $this->stash->getFile( $fileName );
 133                 if ( $type === 'thumb' ) {
 134                         $srcNamePos = strrpos( $thumbPart, $fileName );
 135                         if ( $srcNamePos === false || $srcNamePos < 1 ) {
 136                                 throw new UploadStashBadPathException( 'Unrecognized thumb name' );
 137                         }
 138                         $paramString = substr( $thumbPart, 0, $srcNamePos - 1 );
 139
 140                         $handler = $file->getHandler();
 141                         if ( $handler ) {
 142                                 $params = $handler->parseParamString( $paramString );
 143
 144                                 return array( 'file' => $file, 'type' => $type, 'params' => $params );
 145                         } else {
 146                                 throw new UploadStashBadPathException( 'No handler found for ' .
 147                                         "mime {$file->getMimeType()} of file {$file->getPath()}" );
 148                         }
 149                 }
 150
 151                 return array( 'file' => $file, 'type' => $type );
 152         }
 153
 154         /**
 155          * Get a thumbnail for file, either generated locally or remotely, and stream it out
 156          *
 157          * @param File $file
 158          * @param array $params
 159          *
 160          * @return bool Success
 161          */
 162         private function outputThumbFromStash( $file, $params ) {
 163                 $flags = 0;
 164                 // this config option, if it exists, points to a "scaler", as you might find in
 165                 // the Wikimedia Foundation cluster. See outputRemoteScaledThumb(). This
 166                 // is part of our horrible NFS-based system, we create a file on a mount
 167                 // point here, but fetch the scaled file from somewhere else that
 168                 // happens to share it over NFS.
 169                 if ( $this->getConfig()->get( 'UploadStashScalerBaseUrl' ) ) {
 170                         $this->outputRemoteScaledThumb( $file, $params, $flags );
 171                 } else {
 172                         $this->outputLocallyScaledThumb( $file, $params, $flags );
 173                 }
 174         }
 175
 176         /**
 177          * Scale a file (probably with a locally installed imagemagick, or similar)
 178          * and output it to STDOUT.
 179          * @param File $file
 180          * @param array $params Scaling parameters ( e.g. array( width => '50' ) );
 181          * @param int $flags Scaling flags ( see File:: constants )
 182          * @throws MWException|UploadStashFileNotFoundException
 183          * @return bool Success
 184          */
 185         private function outputLocallyScaledThumb( $file, $params, $flags ) {
 186                 // n.b. this is stupid, we insist on re-transforming the file every time we are invoked. We rely
 187                 // on HTTP caching to ensure this doesn't happen.
 188
 189                 $flags |= File::RENDER_NOW;
 190
 191                 $thumbnailImage = $file->transform( $params, $flags );
 192                 if ( !$thumbnailImage ) {
 193                         throw new MWException( 'Could not obtain thumbnail' );
 194                 }
 195
 196                 // we should have just generated it locally
 197                 if ( !$thumbnailImage->getStoragePath() ) {
 198                         throw new UploadStashFileNotFoundException( "no local path for scaled item" );
 199                 }
 200
 201                 // now we should construct a File, so we can get MIME and other such info in a standard way
 202                 // n.b. MIME type may be different from original (ogx original -> jpeg thumb)
 203                 $thumbFile = new UnregisteredLocalFile( false,
 204                         $this->stash->repo, $thumbnailImage->getStoragePath(), false );
 205                 if ( !$thumbFile ) {
 206                         throw new UploadStashFileNotFoundException( "couldn't create local file object for thumbnail" );
 207                 }
 208
 209                 return $this->outputLocalFile( $thumbFile );
 210         }
 211
 212         /**
 213          * Scale a file with a remote "scaler", as exists on the Wikimedia Foundation
 214          * cluster, and output it to STDOUT.
 215          * Note: Unlike the usual thumbnail process, the web client never sees the
 216          * cluster URL; we do the whole HTTP transaction to the scaler ourselves
 217          * and cat the results out.
 218          * Note: We rely on NFS to have propagated the file contents to the scaler.
 219          * However, we do not rely on the thumbnail being created in NFS and then
 220          * propagated back to our filesystem. Instead we take the results of the
 221          * HTTP request instead.
 222          * Note: No caching is being done here, although we are instructing the
 223          * client to cache it forever.
 224          *
 225          * @param File $file
 226          * @param array $params Scaling parameters ( e.g. array( width => '50' ) );
 227          * @param int $flags Scaling flags ( see File:: constants )
 228          * @throws MWException
 229          * @return bool Success
 230          */
 231         private function outputRemoteScaledThumb( $file, $params, $flags ) {
 232                 // This option probably looks something like
 233                 // '//upload.wikimedia.org/wikipedia/test/thumb/temp'. Do not use
 234                 // trailing slash.
 235                 $scalerBaseUrl = $this->getConfig()->get( 'UploadStashScalerBaseUrl' );
 236
 237                 if ( preg_match( '/^\/\//', $scalerBaseUrl ) ) {
 238                         // this is apparently a protocol-relative URL, which makes no sense in this context,
 239                         // since this is used for communication that's internal to the application.
 240                         // default to http.
 241                         $scalerBaseUrl = wfExpandUrl( $scalerBaseUrl, PROTO_CANONICAL );
 242                 }
 243
 244                 // We need to use generateThumbName() instead of thumbName(), because
 245                 // the suffix needs to match the file name for the remote thumbnailer
 246                 // to work
 247                 $scalerThumbName = $file->generateThumbName( $file->getName(), $params );
 248                 $scalerThumbUrl = $scalerBaseUrl . '/' . $file->getUrlRel() .
 249                         '/' . rawurlencode( $scalerThumbName );
 250
 251                 // make a curl call to the scaler to create a thumbnail
 252                 $httpOptions = array(
 253                         'method' => 'GET',
 254                         'timeout' => 5 // T90599 attempt to time out cleanly
 255                 );
 256                 $req = MWHttpRequest::factory( $scalerThumbUrl, $httpOptions, __METHOD__ );
 257                 $status = $req->execute();
 258                 if ( !$status->isOK() ) {
 259                         $errors = $status->getErrorsArray();
 260                         $errorStr = "Fetching thumbnail failed: " . print_r( $errors, 1 );
 261                         $errorStr .= "\nurl = $scalerThumbUrl\n";
 262                         throw new MWException( $errorStr );
 263                 }
 264                 $contentType = $req->getResponseHeader( "content-type" );
 265                 if ( !$contentType ) {
 266                         throw new MWException( "Missing content-type header" );
 267                 }
 268
 269                 return $this->outputContents( $req->getContent(), $contentType );
 270         }
 271
 272         /**
 273          * Output HTTP response for file
 274          * Side effect: writes HTTP response to STDOUT.
 275          *
 276          * @param File $file File object with a local path (e.g. UnregisteredLocalFile,
 277          *   LocalFile. Oddly these don't share an ancestor!)
 278          * @throws SpecialUploadStashTooLargeException
 279          * @return bool
 280          */
 281         private function outputLocalFile( File $file ) {
 282                 if ( $file->getSize() > self::MAX_SERVE_BYTES ) {
 283                         throw new SpecialUploadStashTooLargeException();
 284                 }
 285
 286                 return $file->getRepo()->streamFile( $file->getPath(),
 287                         array( 'Content-Transfer-Encoding: binary',
 288                                 'Expires: Sun, 17-Jan-2038 19:14:07 GMT' )
 289                 );
 290         }
 291
 292         /**
 293          * Output HTTP response of raw content
 294          * Side effect: writes HTTP response to STDOUT.
 295          * @param string $content Content
 296          * @param string $contentType MIME type
 297          * @throws SpecialUploadStashTooLargeException
 298          * @return bool
 299          */
 300         private function outputContents( $content, $contentType ) {
 301                 $size = strlen( $content );
 302                 if ( $size > self::MAX_SERVE_BYTES ) {
 303                         throw new SpecialUploadStashTooLargeException();
 304                 }
 305                 self::outputFileHeaders( $contentType, $size );
 306                 print $content;
 307
 308                 return true;
 309         }
 310
 311         /**
 312          * Output headers for streaming
 313          * @todo Unsure about encoding as binary; if we received from HTTP perhaps
 314          * we should use that encoding, concatenated with semicolon to `$contentType` as it
 315          * usually is.
 316          * Side effect: preps PHP to write headers to STDOUT.
 317          * @param string $contentType String suitable for content-type header
 318          * @param string $size Length in bytes
 319          */
 320         private static function outputFileHeaders( $contentType, $size ) {
 321                 header( "Content-Type: $contentType", true );
 322                 header( 'Content-Transfer-Encoding: binary', true );
 323                 header( 'Expires: Sun, 17-Jan-2038 19:14:07 GMT', true );
 324                 // Bug 53032 - It shouldn't be a problem here, but let's be safe and not cache
 325                 header( 'Cache-Control: private' );
 326                 header( "Content-Length: $size", true );
 327         }
 328
 329         /**
 330          * Static callback for the HTMLForm in showUploads, to process
 331          * Note the stash has to be recreated since this is being called in a static context.
 332          * This works, because there really is only one stash per logged-in user, despite appearances.
 333          *
 334          * @param array $formData
 335          * @param HTMLForm $form
 336          * @return Status
 337          */
 338         public static function tryClearStashedUploads( $formData, $form ) {
 339                 if ( isset( $formData['Clear'] ) ) {
 340                         $stash = RepoGroup::singleton()->getLocalRepo()->getUploadStash( $form->getUser() );
 341                         wfDebug( 'stash has: ' . print_r( $stash->listFiles(), true ) . "\n" );
 342
 343                         if ( !$stash->clear() ) {
 344                                 return Status::newFatal( 'uploadstash-errclear' );
 345                         }
 346                 }
 347
 348                 return Status::newGood();
 349         }
 350
 351         /**
 352          * Default action when we don't have a subpage -- just show links to the uploads we have,
 353          * Also show a button to clear stashed files
 354          * @return bool
 355          */
 356         private function showUploads() {
 357                 // sets the title, etc.
 358                 $this->setHeaders();
 359                 $this->outputHeader();
 360
 361                 // create the form, which will also be used to execute a callback to process incoming form data
 362                 // this design is extremely dubious, but supposedly HTMLForm is our standard now?
 363
 364                 $context = new DerivativeContext( $this->getContext() );
 365                 $context->setTitle( $this->getPageTitle() ); // Remove subpage
 366                 $form = new HTMLForm( array(
 367                         'Clear' => array(
 368                                 'type' => 'hidden',
 369                                 'default' => true,
 370                                 'name' => 'clear',
 371                         )
 372                 ), $context, 'clearStashedUploads' );
 373                 $form->setSubmitCallback( array( __CLASS__, 'tryClearStashedUploads' ) );
 374                 $form->setSubmitTextMsg( 'uploadstash-clear' );
 375
 376                 $form->prepareForm();
 377                 $formResult = $form->tryAuthorizedSubmit();
 378
 379                 // show the files + form, if there are any, or just say there are none
 380                 $refreshHtml = Html::element( 'a',
 381                         array( 'href' => $this->getPageTitle()->getLocalURL() ),
 382                         $this->msg( 'uploadstash-refresh' )->text() );
 383                 $files = $this->stash->listFiles();
 384                 if ( $files && count( $files ) ) {
 385                         sort( $files );
 386                         $fileListItemsHtml = '';
 387                         foreach ( $files as $file ) {
 388                                 // TODO: Use Linker::link or even construct the list in plain wikitext
 389                                 $fileListItemsHtml .= Html::rawElement( 'li', array(),
 390                                         Html::element( 'a', array( 'href' =>
 391                                                 $this->getPageTitle( "file/$file" )->getLocalURL() ), $file )
 392                                 );
 393                         }
 394                         $this->getOutput()->addHtml( Html::rawElement( 'ul', array(), $fileListItemsHtml ) );
 395                         $form->displayForm( $formResult );
 396                         $this->getOutput()->addHtml( Html::rawElement( 'p', array(), $refreshHtml ) );
 397                 } else {
 398                         $this->getOutput()->addHtml( Html::rawElement( 'p', array(),
 399                                 Html::element( 'span', array(), $this->msg( 'uploadstash-nofiles' )->text() )
 400                                 . ' '
 401                                 . $refreshHtml
 402                         ) );
 403                 }
 404
 405                 return true;
 406         }
 407 }
 408
 409 class SpecialUploadStashTooLargeException extends MWException {
 410 }