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