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