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
  61          *   http://example.com/wiki/Special:UploadStash/foo.jpg, the "foo.jpg" part
  62          * @return bool Success
  63          */
  64         public function execute( $subPage ) {
  65                 $this->checkPermissions();
  66
  67                 if ( $subPage === null || $subPage === '' ) {
  68                         return $this->showUploads();
  69                 }
  70
  71                 return $this->showUpload( $subPage );
  72         }
  73
  74         /**
  75          * If file available in stash, cats it out to the client as a simple HTTP response.
  76          * n.b. Most sanity checking done in UploadStashLocalFile, so this is straightforward.
  77          *
  78          * @param string $key The key of a particular requested file
  79          * @throws HttpError
  80          * @return bool
  81          */
  82         public function showUpload( $key ) {
  83                 // prevent callers from doing standard HTML output -- we'll take it from here
  84                 $this->getOutput()->disable();
  85
  86                 try {
  87                         $params = $this->parseKey( $key );
  88                         if ( $params['type'] === 'thumb' ) {
  89                                 return $this->outputThumbFromStash( $params['file'], $params['params'] );
  90                         } else {
  91                                 return $this->outputLocalFile( $params['file'] );
  92                         }
  93                 } catch ( UploadStashFileNotFoundException $e ) {
  94                         $code = 404;
  95                         $message = $e->getMessage();
  96                 } catch ( UploadStashZeroLengthFileException $e ) {
  97                         $code = 500;
  98                         $message = $e->getMessage();
  99                 } catch ( UploadStashBadPathException $e ) {
 100                         $code = 500;
 101                         $message = $e->getMessage();
 102                 } catch ( SpecialUploadStashTooLargeException $e ) {
 103                         $code = 500;
 104                         $message = 'Cannot serve a file larger than ' . self::MAX_SERVE_BYTES .
 105                                 ' bytes. ' . $e->getMessage();
 106                 } catch ( Exception $e ) {
 107                         $code = 500;
 108                         $message = $e->getMessage();
 109                 }
 110
 111                 throw new HttpError( $code, $message );
 112         }
 113
 114         /**
 115          * Parse the key passed to the SpecialPage. Returns an array containing
 116          * the associated file object, the type ('file' or 'thumb') and if
 117          * application the transform parameters
 118          *
 119          * @param string $key
 120          * @throws UploadStashBadPathException
 121          * @return array
 122          */
 123         private function parseKey( $key ) {
 124                 $type = strtok( $key, '/' );
 125
 126                 if ( $type !== 'file' && $type !== 'thumb' ) {
 127                         throw new UploadStashBadPathException( "Unknown type '$type'" );
 128                 }
 129                 $fileName = strtok( '/' );
 130                 $thumbPart = strtok( '/' );
 131                 $file = $this->stash->getFile( $fileName );
 132                 if ( $type === 'thumb' ) {
 133                         $srcNamePos = strrpos( $thumbPart, $fileName );
 134                         if ( $srcNamePos === false || $srcNamePos < 1 ) {
 135                                 throw new UploadStashBadPathException( 'Unrecognized thumb name' );
 136                         }
 137                         $paramString = substr( $thumbPart, 0, $srcNamePos - 1 );
 138
 139                         $handler = $file->getHandler();
 140                         if ( $handler ) {
 141                                 $params = $handler->parseParamString( $paramString );
 142
 143                                 return array( 'file' => $file, 'type' => $type, 'params' => $params );
 144                         } else {
 145                                 throw new UploadStashBadPathException( 'No handler found for ' .
 146                                         "mime {$file->getMimeType()} of file {$file->getPath()}" );
 147                         }
 148                 }
 149
 150                 return array( 'file' => $file, 'type' => $type );
 151         }
 152
 153         /**
 154          * Get a thumbnail for file, either generated locally or remotely, and stream it out
 155          *
 156          * @param File $file
 157          * @param array $params
 158          *
 159          * @return bool Success
 160          */
 161         private function outputThumbFromStash( $file, $params ) {
 162                 $flags = 0;
 163                 // this config option, if it exists, points to a "scaler", as you might find in
 164                 // the Wikimedia Foundation cluster. See outputRemoteScaledThumb(). This
 165                 // is part of our horrible NFS-based system, we create a file on a mount
 166                 // point here, but fetch the scaled file from somewhere else that
 167                 // happens to share it over NFS.
 168                 if ( $this->getConfig()->get( 'UploadStashScalerBaseUrl' ) ) {
 169                         $this->outputRemoteScaledThumb( $file, $params, $flags );
 170                 } else {
 171                         $this->outputLocallyScaledThumb( $file, $params, $flags );
 172                 }
 173         }
 174
 175         /**
 176          * Scale a file (probably with a locally installed imagemagick, or similar)
 177          * and output it to STDOUT.
 178          * @param File $file
 179          * @param array $params Scaling parameters ( e.g. array( width => '50' ) );
 180          * @param int $flags Scaling flags ( see File:: constants )
 181          * @throws MWException|UploadStashFileNotFoundException
 182          * @return bool Success
 183          */
 184         private function outputLocallyScaledThumb( $file, $params, $flags ) {
 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. MIME type 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
 213          * cluster, and output it to STDOUT.
 214          * Note: Unlike the usual thumbnail process, the web client never sees the
 215          * cluster URL; we do the whole HTTP transaction to the scaler ourselves
 216          * and cat the results out.
 217          * Note: We rely on NFS to have propagated the file contents to the scaler.
 218          * However, we do not rely on the thumbnail being created in NFS and then
 219          * propagated back to our filesystem. Instead we take the results of the
 220          * HTTP request instead.
 221          * Note: No caching is being done here, although we are instructing the
 222          * client to cache it forever.
 223          *
 224          * @param File $file
 225          * @param array $params Scaling parameters ( e.g. array( width => '50' ) );
 226          * @param int $flags Scaling flags ( see File:: constants )
 227          * @throws MWException
 228          * @return bool Success
 229          */
 230         private function outputRemoteScaledThumb( $file, $params, $flags ) {
 231                 // This option probably looks something like
 232                 // 'http://upload.wikimedia.org/wikipedia/test/thumb/temp'. Do not use
 233                 // trailing slash.
 234                 $scalerBaseUrl = $this->getConfig()->get( 'UploadStashScalerBaseUrl' );
 235
 236                 if ( preg_match( '/^\/\//', $scalerBaseUrl ) ) {
 237                         // this is apparently a protocol-relative URL, which makes no sense in this context,
 238                         // since this is used for communication that's internal to the application.
 239                         // default to http.
 240                         $scalerBaseUrl = wfExpandUrl( $scalerBaseUrl, PROTO_CANONICAL );
 241                 }
 242
 243                 // We need to use generateThumbName() instead of thumbName(), because
 244                 // the suffix needs to match the file name for the remote thumbnailer
 245                 // to work
 246                 $scalerThumbName = $file->generateThumbName( $file->getName(), $params );
 247                 $scalerThumbUrl = $scalerBaseUrl . '/' . $file->getUrlRel() .
 248                         '/' . rawurlencode( $scalerThumbName );
 249
 250                 // make a curl call to the scaler to create a thumbnail
 251                 $httpOptions = array(
 252                         'method' => 'GET',
 253                         'timeout' => 'default'
 254                 );
 255                 $req = MWHttpRequest::factory( $scalerThumbUrl, $httpOptions );
 256                 $status = $req->execute();
 257                 if ( !$status->isOK() ) {
 258                         $errors = $status->getErrorsArray();
 259                         $errorStr = "Fetching thumbnail failed: " . print_r( $errors, 1 );
 260                         $errorStr .= "\nurl = $scalerThumbUrl\n";
 261                         throw new MWException( $errorStr );
 262                 }
 263                 $contentType = $req->getResponseHeader( "content-type" );
 264                 if ( !$contentType ) {
 265                         throw new MWException( "Missing content-type header" );
 266                 }
 267
 268                 return $this->outputContents( $req->getContent(), $contentType );
 269         }
 270
 271         /**
 272          * Output HTTP response for file
 273          * Side effect: writes HTTP response to STDOUT.
 274          *
 275          * @param File $file File object with a local path (e.g. UnregisteredLocalFile,
 276          *   LocalFile. Oddly these don't share an ancestor!)
 277          * @throws SpecialUploadStashTooLargeException
 278          * @return bool
 279          */
 280         private function outputLocalFile( File $file ) {
 281                 if ( $file->getSize() > self::MAX_SERVE_BYTES ) {
 282                         throw new SpecialUploadStashTooLargeException();
 283                 }
 284
 285                 return $file->getRepo()->streamFile( $file->getPath(),
 286                         array( 'Content-Transfer-Encoding: binary',
 287                                 'Expires: Sun, 17-Jan-2038 19:14:07 GMT' )
 288                 );
 289         }
 290
 291         /**
 292          * Output HTTP response of raw content
 293          * Side effect: writes HTTP response to STDOUT.
 294          * @param string $content Content
 295          * @param string $contentType MIME type
 296          * @throws SpecialUploadStashTooLargeException
 297          * @return bool
 298          */
 299         private function outputContents( $content, $contentType ) {
 300                 $size = strlen( $content );
 301                 if ( $size > self::MAX_SERVE_BYTES ) {
 302                         throw new SpecialUploadStashTooLargeException();
 303                 }
 304                 self::outputFileHeaders( $contentType, $size );
 305                 print $content;
 306
 307                 return true;
 308         }
 309
 310         /**
 311          * Output headers for streaming
 312          * @todo Unsure about encoding as binary; if we received from HTTP perhaps
 313          * we should use that encoding, concatenated with semicolon to `$contentType` as it
 314          * usually is.
 315          * Side effect: preps PHP to write headers to STDOUT.
 316          * @param string $contentType String suitable for content-type header
 317          * @param string $size Length in bytes
 318          */
 319         private static function outputFileHeaders( $contentType, $size ) {
 320                 header( "Content-Type: $contentType", true );
 321                 header( 'Content-Transfer-Encoding: binary', true );
 322                 header( 'Expires: Sun, 17-Jan-2038 19:14:07 GMT', true );
 323                 // Bug 53032 - It shouldn't be a problem here, but let's be safe and not cache
 324                 header( 'Cache-Control: private' );
 325                 header( "Content-Length: $size", true );
 326         }
 327
 328         /**
 329          * Static callback for the HTMLForm in showUploads, to process
 330          * Note the stash has to be recreated since this is being called in a static context.
 331          * This works, because there really is only one stash per logged-in user, despite appearances.
 332          *
 333          * @param array $formData
 334          * @return Status
 335          */
 336         public static function tryClearStashedUploads( $formData ) {
 337                 if ( isset( $formData['Clear'] ) ) {
 338                         $stash = RepoGroup::singleton()->getLocalRepo()->getUploadStash();
 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 }