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