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