includes/filerepo/backend/FSFileBackend.php

   1 <?php
   2 /**
   3  * File system based backend.
   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 FileBackend
  22  * @author Aaron Schulz
  23  */
  24
  25 /**
  26  * @brief Class for a file system (FS) based file backend.
  27  *
  28  * All "containers" each map to a directory under the backend's base directory.
  29  * For backwards-compatibility, some container paths can be set to custom paths.
  30  * The wiki ID will not be used in any custom paths, so this should be avoided.
  31  *
  32  * Having directories with thousands of files will diminish performance.
  33  * Sharding can be accomplished by using FileRepo-style hash paths.
  34  *
  35  * Status messages should avoid mentioning the internal FS paths.
  36  * PHP warnings are assumed to be logged rather than output.
  37  *
  38  * @ingroup FileBackend
  39  * @since 1.19
  40  */
  41 class FSFileBackend extends FileBackendStore {
  42         protected $basePath; // string; directory holding the container directories
  43         /** @var Array Map of container names to root paths */
  44         protected $containerPaths = array(); // for custom container paths
  45         protected $fileMode; // integer; file permission mode
  46
  47         protected $hadWarningErrors = array();
  48
  49         /**
  50          * @see FileBackendStore::__construct()
  51          * Additional $config params include:
  52          *    basePath       : File system directory that holds containers.
  53          *    containerPaths : Map of container names to custom file system directories.
  54          *                     This should only be used for backwards-compatibility.
  55          *    fileMode       : Octal UNIX file permissions to use on files stored.
  56          */
  57         public function __construct( array $config ) {
  58                 parent::__construct( $config );
  59
  60                 // Remove any possible trailing slash from directories
  61                 if ( isset( $config['basePath'] ) ) {
  62                         $this->basePath = rtrim( $config['basePath'], '/' ); // remove trailing slash
  63                 } else {
  64                         $this->basePath = null; // none; containers must have explicit paths
  65                 }
  66
  67                 if ( isset( $config['containerPaths'] ) ) {
  68                         $this->containerPaths = (array)$config['containerPaths'];
  69                         foreach ( $this->containerPaths as &$path ) {
  70                                 $path = rtrim( $path, '/' );  // remove trailing slash
  71                         }
  72                 }
  73
  74                 $this->fileMode = isset( $config['fileMode'] )
  75                         ? $config['fileMode']
  76                         : 0644;
  77         }
  78
  79         /**
  80          * @see FileBackendStore::resolveContainerPath()
  81          * @return null|string
  82          */
  83         protected function resolveContainerPath( $container, $relStoragePath ) {
  84                 // Check that container has a root directory
  85                 if ( isset( $this->containerPaths[$container] ) || isset( $this->basePath ) ) {
  86                         // Check for sane relative paths (assume the base paths are OK)
  87                         if ( $this->isLegalRelPath( $relStoragePath ) ) {
  88                                 return $relStoragePath;
  89                         }
  90                 }
  91                 return null;
  92         }
  93
  94         /**
  95          * Sanity check a relative file system path for validity
  96          *
  97          * @param $path string Normalized relative path
  98          * @return bool
  99          */
 100         protected function isLegalRelPath( $path ) {
 101                 // Check for file names longer than 255 chars
 102                 if ( preg_match( '![^/]{256}!', $path ) ) { // ext3/NTFS
 103                         return false;
 104                 }
 105                 if ( wfIsWindows() ) { // NTFS
 106                         return !preg_match( '![:*?"<>|]!', $path );
 107                 } else {
 108                         return true;
 109                 }
 110         }
 111
 112         /**
 113          * Given the short (unresolved) and full (resolved) name of
 114          * a container, return the file system path of the container.
 115          *
 116          * @param $shortCont string
 117          * @param $fullCont string
 118          * @return string|null
 119          */
 120         protected function containerFSRoot( $shortCont, $fullCont ) {
 121                 if ( isset( $this->containerPaths[$shortCont] ) ) {
 122                         return $this->containerPaths[$shortCont];
 123                 } elseif ( isset( $this->basePath ) ) {
 124                         return "{$this->basePath}/{$fullCont}";
 125                 }
 126                 return null; // no container base path defined
 127         }
 128
 129         /**
 130          * Get the absolute file system path for a storage path
 131          *
 132          * @param $storagePath string Storage path
 133          * @return string|null
 134          */
 135         protected function resolveToFSPath( $storagePath ) {
 136                 list( $fullCont, $relPath ) = $this->resolveStoragePathReal( $storagePath );
 137                 if ( $relPath === null ) {
 138                         return null; // invalid
 139                 }
 140                 list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $storagePath );
 141                 $fsPath = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
 142                 if ( $relPath != '' ) {
 143                         $fsPath .= "/{$relPath}";
 144                 }
 145                 return $fsPath;
 146         }
 147
 148         /**
 149          * @see FileBackendStore::isPathUsableInternal()
 150          * @return bool
 151          */
 152         public function isPathUsableInternal( $storagePath ) {
 153                 $fsPath = $this->resolveToFSPath( $storagePath );
 154                 if ( $fsPath === null ) {
 155                         return false; // invalid
 156                 }
 157                 $parentDir = dirname( $fsPath );
 158
 159                 if ( file_exists( $fsPath ) ) {
 160                         $ok = is_file( $fsPath ) && is_writable( $fsPath );
 161                 } else {
 162                         $ok = is_dir( $parentDir ) && is_writable( $parentDir );
 163                 }
 164
 165                 return $ok;
 166         }
 167
 168         /**
 169          * @see FileBackendStore::doStoreInternal()
 170          * @return Status
 171          */
 172         protected function doStoreInternal( array $params ) {
 173                 $status = Status::newGood();
 174
 175                 $dest = $this->resolveToFSPath( $params['dst'] );
 176                 if ( $dest === null ) {
 177                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 178                         return $status;
 179                 }
 180
 181                 if ( file_exists( $dest ) ) {
 182                         if ( !empty( $params['overwrite'] ) ) {
 183                                 $ok = unlink( $dest );
 184                                 if ( !$ok ) {
 185                                         $status->fatal( 'backend-fail-delete', $params['dst'] );
 186                                         return $status;
 187                                 }
 188                         } else {
 189                                 $status->fatal( 'backend-fail-alreadyexists', $params['dst'] );
 190                                 return $status;
 191                         }
 192                 }
 193
 194                 if ( !empty( $params['async'] ) ) { // deferred
 195                         $cmd = implode( ' ', array( wfIsWindows() ? 'COPY' : 'cp',
 196                                 wfEscapeShellArg( $this->cleanPathSlashes( $params['src'] ) ),
 197                                 wfEscapeShellArg( $this->cleanPathSlashes( $dest ) )
 198                         ) );
 199                         $status->value = new FSFileOpHandle( $this, $params, 'Store', $cmd, $dest );
 200                 } else { // immediate write
 201                         $ok = copy( $params['src'], $dest );
 202                         // In some cases (at least over NFS), copy() returns true when it fails
 203                         if ( !$ok || ( filesize( $params['src'] ) !== filesize( $dest ) ) ) {
 204                                 if ( $ok ) { // PHP bug
 205                                         unlink( $dest ); // remove broken file
 206                                         trigger_error( __METHOD__ . ": copy() failed but returned true." );
 207                                 }
 208                                 $status->fatal( 'backend-fail-store', $params['src'], $params['dst'] );
 209                                 return $status;
 210                         }
 211                         $this->chmod( $dest );
 212                 }
 213
 214                 return $status;
 215         }
 216
 217         /**
 218          * @see FSFileBackend::doExecuteOpHandlesInternal()
 219          */
 220         protected function _getResponseStore( $errors, Status $status, array $params, $cmd ) {
 221                 if ( $errors !== '' && !( wfIsWindows() && $errors[0] === " " ) ) {
 222                         $status->fatal( 'backend-fail-store', $params['src'], $params['dst'] );
 223                         trigger_error( "$cmd\n$errors", E_USER_WARNING ); // command output
 224                 }
 225         }
 226
 227         /**
 228          * @see FileBackendStore::doCopyInternal()
 229          * @return Status
 230          */
 231         protected function doCopyInternal( array $params ) {
 232                 $status = Status::newGood();
 233
 234                 $source = $this->resolveToFSPath( $params['src'] );
 235                 if ( $source === null ) {
 236                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 237                         return $status;
 238                 }
 239
 240                 $dest = $this->resolveToFSPath( $params['dst'] );
 241                 if ( $dest === null ) {
 242                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 243                         return $status;
 244                 }
 245
 246                 if ( file_exists( $dest ) ) {
 247                         if ( !empty( $params['overwrite'] ) ) {
 248                                 $ok = unlink( $dest );
 249                                 if ( !$ok ) {
 250                                         $status->fatal( 'backend-fail-delete', $params['dst'] );
 251                                         return $status;
 252                                 }
 253                         } else {
 254                                 $status->fatal( 'backend-fail-alreadyexists', $params['dst'] );
 255                                 return $status;
 256                         }
 257                 }
 258
 259                 if ( !empty( $params['async'] ) ) { // deferred
 260                         $cmd = implode( ' ', array( wfIsWindows() ? 'COPY' : 'cp',
 261                                 wfEscapeShellArg( $this->cleanPathSlashes( $source ) ),
 262                                 wfEscapeShellArg( $this->cleanPathSlashes( $dest ) )
 263                         ) );
 264                         $status->value = new FSFileOpHandle( $this, $params, 'Copy', $cmd, $dest );
 265                 } else { // immediate write
 266                         $ok = copy( $source, $dest );
 267                         // In some cases (at least over NFS), copy() returns true when it fails
 268                         if ( !$ok || ( filesize( $source ) !== filesize( $dest ) ) ) {
 269                                 if ( $ok ) { // PHP bug
 270                                         unlink( $dest ); // remove broken file
 271                                         trigger_error( __METHOD__ . ": copy() failed but returned true." );
 272                                 }
 273                                 $status->fatal( 'backend-fail-copy', $params['src'], $params['dst'] );
 274                                 return $status;
 275                         }
 276                         $this->chmod( $dest );
 277                 }
 278
 279                 return $status;
 280         }
 281
 282         /**
 283          * @see FSFileBackend::doExecuteOpHandlesInternal()
 284          */
 285         protected function _getResponseCopy( $errors, Status $status, array $params, $cmd ) {
 286                 if ( $errors !== '' && !( wfIsWindows() && $errors[0] === " " ) ) {
 287                         $status->fatal( 'backend-fail-copy', $params['src'], $params['dst'] );
 288                         trigger_error( "$cmd\n$errors", E_USER_WARNING ); // command output
 289                 }
 290         }
 291
 292         /**
 293          * @see FileBackendStore::doMoveInternal()
 294          * @return Status
 295          */
 296         protected function doMoveInternal( array $params ) {
 297                 $status = Status::newGood();
 298
 299                 $source = $this->resolveToFSPath( $params['src'] );
 300                 if ( $source === null ) {
 301                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 302                         return $status;
 303                 }
 304
 305                 $dest = $this->resolveToFSPath( $params['dst'] );
 306                 if ( $dest === null ) {
 307                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 308                         return $status;
 309                 }
 310
 311                 if ( file_exists( $dest ) ) {
 312                         if ( !empty( $params['overwrite'] ) ) {
 313                                 // Windows does not support moving over existing files
 314                                 if ( wfIsWindows() ) {
 315                                         $ok = unlink( $dest );
 316                                         if ( !$ok ) {
 317                                                 $status->fatal( 'backend-fail-delete', $params['dst'] );
 318                                                 return $status;
 319                                         }
 320                                 }
 321                         } else {
 322                                 $status->fatal( 'backend-fail-alreadyexists', $params['dst'] );
 323                                 return $status;
 324                         }
 325                 }
 326
 327                 if ( !empty( $params['async'] ) ) { // deferred
 328                         $cmd = implode( ' ', array( wfIsWindows() ? 'MOVE' : 'mv',
 329                                 wfEscapeShellArg( $this->cleanPathSlashes( $source ) ),
 330                                 wfEscapeShellArg( $this->cleanPathSlashes( $dest ) )
 331                         ) );
 332                         $status->value = new FSFileOpHandle( $this, $params, 'Move', $cmd );
 333                 } else { // immediate write
 334                         $ok = rename( $source, $dest );
 335                         clearstatcache(); // file no longer at source
 336                         if ( !$ok ) {
 337                                 $status->fatal( 'backend-fail-move', $params['src'], $params['dst'] );
 338                                 return $status;
 339                         }
 340                 }
 341
 342                 return $status;
 343         }
 344
 345         /**
 346          * @see FSFileBackend::doExecuteOpHandlesInternal()
 347          */
 348         protected function _getResponseMove( $errors, Status $status, array $params, $cmd ) {
 349                 if ( $errors !== '' && !( wfIsWindows() && $errors[0] === " " ) ) {
 350                         $status->fatal( 'backend-fail-move', $params['src'], $params['dst'] );
 351                         trigger_error( "$cmd\n$errors", E_USER_WARNING ); // command output
 352                 }
 353         }
 354
 355         /**
 356          * @see FileBackendStore::doDeleteInternal()
 357          * @return Status
 358          */
 359         protected function doDeleteInternal( array $params ) {
 360                 $status = Status::newGood();
 361
 362                 $source = $this->resolveToFSPath( $params['src'] );
 363                 if ( $source === null ) {
 364                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 365                         return $status;
 366                 }
 367
 368                 if ( !is_file( $source ) ) {
 369                         if ( empty( $params['ignoreMissingSource'] ) ) {
 370                                 $status->fatal( 'backend-fail-delete', $params['src'] );
 371                         }
 372                         return $status; // do nothing; either OK or bad status
 373                 }
 374
 375                 if ( !empty( $params['async'] ) ) { // deferred
 376                         $cmd = implode( ' ', array( wfIsWindows() ? 'DEL' : 'unlink',
 377                                 wfEscapeShellArg( $this->cleanPathSlashes( $source ) )
 378                         ) );
 379                         $status->value = new FSFileOpHandle( $this, $params, 'Copy', $cmd );
 380                 } else { // immediate write
 381                         $ok = unlink( $source );
 382                         if ( !$ok ) {
 383                                 $status->fatal( 'backend-fail-delete', $params['src'] );
 384                                 return $status;
 385                         }
 386                 }
 387
 388                 return $status;
 389         }
 390
 391         /**
 392          * @see FSFileBackend::doExecuteOpHandlesInternal()
 393          */
 394         protected function _getResponseDelete( $errors, Status $status, array $params, $cmd ) {
 395                 if ( $errors !== '' && !( wfIsWindows() && $errors[0] === " " ) ) {
 396                         $status->fatal( 'backend-fail-delete', $params['src'] );
 397                         trigger_error( "$cmd\n$errors", E_USER_WARNING ); // command output
 398                 }
 399         }
 400
 401         /**
 402          * @see FileBackendStore::doCreateInternal()
 403          * @return Status
 404          */
 405         protected function doCreateInternal( array $params ) {
 406                 $status = Status::newGood();
 407
 408                 $dest = $this->resolveToFSPath( $params['dst'] );
 409                 if ( $dest === null ) {
 410                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 411                         return $status;
 412                 }
 413
 414                 if ( file_exists( $dest ) ) {
 415                         if ( !empty( $params['overwrite'] ) ) {
 416                                 $ok = unlink( $dest );
 417                                 if ( !$ok ) {
 418                                         $status->fatal( 'backend-fail-delete', $params['dst'] );
 419                                         return $status;
 420                                 }
 421                         } else {
 422                                 $status->fatal( 'backend-fail-alreadyexists', $params['dst'] );
 423                                 return $status;
 424                         }
 425                 }
 426
 427                 if ( !empty( $params['async'] ) ) { // deferred
 428                         $tempFile = TempFSFile::factory( 'create_', 'tmp' );
 429                         if ( !$tempFile ) {
 430                                 $status->fatal( 'backend-fail-create', $params['dst'] );
 431                                 return $status;
 432                         }
 433                         $bytes = file_put_contents( $tempFile->getPath(), $params['content'] );
 434                         if ( $bytes === false ) {
 435                                 $status->fatal( 'backend-fail-create', $params['dst'] );
 436                                 return $status;
 437                         }
 438                         $cmd = implode( ' ', array( wfIsWindows() ? 'COPY' : 'cp',
 439                                 wfEscapeShellArg( $this->cleanPathSlashes( $tempFile->getPath() ) ),
 440                                 wfEscapeShellArg( $this->cleanPathSlashes( $dest ) )
 441                         ) );
 442                         $status->value = new FSFileOpHandle( $this, $params, 'Create', $cmd, $dest );
 443                         $tempFile->bind( $status->value );
 444                 } else { // immediate write
 445                         $bytes = file_put_contents( $dest, $params['content'] );
 446                         if ( $bytes === false ) {
 447                                 $status->fatal( 'backend-fail-create', $params['dst'] );
 448                                 return $status;
 449                         }
 450                         $this->chmod( $dest );
 451                 }
 452
 453                 return $status;
 454         }
 455
 456         /**
 457          * @see FSFileBackend::doExecuteOpHandlesInternal()
 458          */
 459         protected function _getResponseCreate( $errors, Status $status, array $params, $cmd ) {
 460                 if ( $errors !== '' && !( wfIsWindows() && $errors[0] === " " ) ) {
 461                         $status->fatal( 'backend-fail-create', $params['dst'] );
 462                         trigger_error( "$cmd\n$errors", E_USER_WARNING ); // command output
 463                 }
 464         }
 465
 466         /**
 467          * @see FileBackendStore::doPrepareInternal()
 468          * @return Status
 469          */
 470         protected function doPrepareInternal( $fullCont, $dirRel, array $params ) {
 471                 $status = Status::newGood();
 472                 list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
 473                 $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
 474                 $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
 475                 if ( !wfMkdirParents( $dir ) ) { // make directory and its parents
 476                         $status->fatal( 'directorycreateerror', $params['dir'] );
 477                 } elseif ( !is_writable( $dir ) ) {
 478                         $status->fatal( 'directoryreadonlyerror', $params['dir'] );
 479                 } elseif ( !is_readable( $dir ) ) {
 480                         $status->fatal( 'directorynotreadableerror', $params['dir'] );
 481                 }
 482                 return $status;
 483         }
 484
 485         /**
 486          * @see FileBackendStore::doSecureInternal()
 487          * @return Status
 488          */
 489         protected function doSecureInternal( $fullCont, $dirRel, array $params ) {
 490                 $status = Status::newGood();
 491                 list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
 492                 $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
 493                 $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
 494                 // Seed new directories with a blank index.html, to prevent crawling...
 495                 if ( !empty( $params['noListing'] ) && !file_exists( "{$dir}/index.html" ) ) {
 496                         $bytes = file_put_contents( "{$dir}/index.html", '' );
 497                         if ( !$bytes ) {
 498                                 $status->fatal( 'backend-fail-create', $params['dir'] . '/index.html' );
 499                                 return $status;
 500                         }
 501                 }
 502                 // Add a .htaccess file to the root of the container...
 503                 if ( !empty( $params['noAccess'] ) ) {
 504                         if ( !file_exists( "{$contRoot}/.htaccess" ) ) {
 505                                 $bytes = file_put_contents( "{$contRoot}/.htaccess", "Deny from all\n" );
 506                                 if ( !$bytes ) {
 507                                         $storeDir = "mwstore://{$this->name}/{$shortCont}";
 508                                         $status->fatal( 'backend-fail-create', "{$storeDir}/.htaccess" );
 509                                         return $status;
 510                                 }
 511                         }
 512                 }
 513                 return $status;
 514         }
 515
 516         /**
 517          * @see FileBackendStore::doCleanInternal()
 518          * @return Status
 519          */
 520         protected function doCleanInternal( $fullCont, $dirRel, array $params ) {
 521                 $status = Status::newGood();
 522                 list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
 523                 $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
 524                 $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
 525                 wfSuppressWarnings();
 526                 if ( is_dir( $dir ) ) {
 527                         rmdir( $dir ); // remove directory if empty
 528                 }
 529                 wfRestoreWarnings();
 530                 return $status;
 531         }
 532
 533         /**
 534          * @see FileBackendStore::doFileExists()
 535          * @return array|bool|null
 536          */
 537         protected function doGetFileStat( array $params ) {
 538                 $source = $this->resolveToFSPath( $params['src'] );
 539                 if ( $source === null ) {
 540                         return false; // invalid storage path
 541                 }
 542
 543                 $this->trapWarnings(); // don't trust 'false' if there were errors
 544                 $stat = is_file( $source ) ? stat( $source ) : false; // regular files only
 545                 $hadError = $this->untrapWarnings();
 546
 547                 if ( $stat ) {
 548                         return array(
 549                                 'mtime' => wfTimestamp( TS_MW, $stat['mtime'] ),
 550                                 'size'  => $stat['size']
 551                         );
 552                 } elseif ( !$hadError ) {
 553                         return false; // file does not exist
 554                 } else {
 555                         return null; // failure
 556                 }
 557         }
 558
 559         /**
 560          * @see FileBackendStore::doClearCache()
 561          */
 562         protected function doClearCache( array $paths = null ) {
 563                 clearstatcache(); // clear the PHP file stat cache
 564         }
 565
 566         /**
 567          * @see FileBackendStore::doDirectoryExists()
 568          * @return bool|null
 569          */
 570         protected function doDirectoryExists( $fullCont, $dirRel, array $params ) {
 571                 list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
 572                 $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
 573                 $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
 574
 575                 $this->trapWarnings(); // don't trust 'false' if there were errors
 576                 $exists = is_dir( $dir );
 577                 $hadError = $this->untrapWarnings();
 578
 579                 return $hadError ? null : $exists;
 580         }
 581
 582         /**
 583          * @see FileBackendStore::getDirectoryListInternal()
 584          * @return Array|null
 585          */
 586         public function getDirectoryListInternal( $fullCont, $dirRel, array $params ) {
 587                 list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
 588                 $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
 589                 $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
 590                 $exists = is_dir( $dir );
 591                 if ( !$exists ) {
 592                         wfDebug( __METHOD__ . "() given directory does not exist: '$dir'\n" );
 593                         return array(); // nothing under this dir
 594                 } elseif ( !is_readable( $dir ) ) {
 595                         wfDebug( __METHOD__ . "() given directory is unreadable: '$dir'\n" );
 596                         return null; // bad permissions?
 597                 }
 598                 return new FSFileBackendDirList( $dir, $params );
 599         }
 600
 601         /**
 602          * @see FileBackendStore::getFileListInternal()
 603          * @return array|FSFileBackendFileList|null
 604          */
 605         public function getFileListInternal( $fullCont, $dirRel, array $params ) {
 606                 list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
 607                 $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
 608                 $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
 609                 $exists = is_dir( $dir );
 610                 if ( !$exists ) {
 611                         wfDebug( __METHOD__ . "() given directory does not exist: '$dir'\n" );
 612                         return array(); // nothing under this dir
 613                 } elseif ( !is_readable( $dir ) ) {
 614                         wfDebug( __METHOD__ . "() given directory is unreadable: '$dir'\n" );
 615                         return null; // bad permissions?
 616                 }
 617                 return new FSFileBackendFileList( $dir, $params );
 618         }
 619
 620         /**
 621          * @see FileBackendStore::getLocalReference()
 622          * @return FSFile|null
 623          */
 624         public function getLocalReference( array $params ) {
 625                 $source = $this->resolveToFSPath( $params['src'] );
 626                 if ( $source === null ) {
 627                         return null;
 628                 }
 629                 return new FSFile( $source );
 630         }
 631
 632         /**
 633          * @see FileBackendStore::getLocalCopy()
 634          * @return null|TempFSFile
 635          */
 636         public function getLocalCopy( array $params ) {
 637                 $source = $this->resolveToFSPath( $params['src'] );
 638                 if ( $source === null ) {
 639                         return null;
 640                 }
 641
 642                 // Create a new temporary file with the same extension...
 643                 $ext = FileBackend::extensionFromPath( $params['src'] );
 644                 $tmpFile = TempFSFile::factory( wfBaseName( $source ) . '_', $ext );
 645                 if ( !$tmpFile ) {
 646                         return null;
 647                 }
 648                 $tmpPath = $tmpFile->getPath();
 649
 650                 // Copy the source file over the temp file
 651                 $ok = copy( $source, $tmpPath );
 652                 if ( !$ok ) {
 653                         return null;
 654                 }
 655
 656                 $this->chmod( $tmpPath );
 657
 658                 return $tmpFile;
 659         }
 660
 661         /**
 662          * @see FileBackendStore::directoriesAreVirtual()
 663          * @return bool
 664          */
 665         protected function directoriesAreVirtual() {
 666                 return false;
 667         }
 668
 669         /**
 670          * @see FileBackendStore::doExecuteOpHandlesInternal()
 671          * @return Array List of corresponding Status objects
 672          */
 673         protected function doExecuteOpHandlesInternal( array $fileOpHandles ) {
 674                 $statuses = array();
 675
 676                 $pipes = array();
 677                 foreach ( $fileOpHandles as $index => $fileOpHandle ) {
 678                         $pipes[$index] = popen( "{$fileOpHandle->cmd} 2>&1", 'r' );
 679                 }
 680
 681                 $errs = array();
 682                 foreach ( $pipes as $index => $pipe ) {
 683                         // Result will be empty on success in *NIX. On Windows,
 684                         // it may be something like "        1 file(s) [copied|moved].".
 685                         $errs[$index] = stream_get_contents( $pipe );
 686                         fclose( $pipe );
 687                 }
 688
 689                 foreach ( $fileOpHandles as $index => $fileOpHandle ) {
 690                         $status = Status::newGood();
 691                         $function = '_getResponse' . $fileOpHandle->call;
 692                         $this->$function( $errs[$index], $status, $fileOpHandle->params, $fileOpHandle->cmd );
 693                         $statuses[$index] = $status;
 694                         if ( $status->isOK() && $fileOpHandle->chmodPath ) {
 695                                 $this->chmod( $fileOpHandle->chmodPath );
 696                         }
 697                 }
 698
 699                 clearstatcache(); // files changed
 700                 return $statuses;
 701         }
 702
 703         /**
 704          * Chmod a file, suppressing the warnings
 705          *
 706          * @param $path string Absolute file system path
 707          * @return bool Success
 708          */
 709         protected function chmod( $path ) {
 710                 wfSuppressWarnings();
 711                 $ok = chmod( $path, $this->fileMode );
 712                 wfRestoreWarnings();
 713
 714                 return $ok;
 715         }
 716
 717         /**
 718          * Clean up directory separators for the given OS
 719          *
 720          * @param $path string FS path
 721          * @return string
 722          */
 723         protected function cleanPathSlashes( $path ) {
 724                 return wfIsWindows() ? strtr( $path, '/', '\\' ) : $path;
 725         }
 726
 727         /**
 728          * Listen for E_WARNING errors and track whether any happen
 729          *
 730          * @return bool
 731          */
 732         protected function trapWarnings() {
 733                 $this->hadWarningErrors[] = false; // push to stack
 734                 set_error_handler( array( $this, 'handleWarning' ), E_WARNING );
 735                 return false; // invoke normal PHP error handler
 736         }
 737
 738         /**
 739          * Stop listening for E_WARNING errors and return true if any happened
 740          *
 741          * @return bool
 742          */
 743         protected function untrapWarnings() {
 744                 restore_error_handler(); // restore previous handler
 745                 return array_pop( $this->hadWarningErrors ); // pop from stack
 746         }
 747
 748         private function handleWarning() {
 749                 $this->hadWarningErrors[count( $this->hadWarningErrors ) - 1] = true;
 750                 return true; // suppress from PHP handler
 751         }
 752 }
 753
 754 /**
 755  * @see FileBackendStoreOpHandle
 756  */
 757 class FSFileOpHandle extends FileBackendStoreOpHandle {
 758         public $cmd; // string; shell command
 759         public $chmodPath; // string; file to chmod
 760
 761         public function __construct( $backend, array $params, $call, $cmd, $chmodPath = null ) {
 762                 $this->backend = $backend;
 763                 $this->params = $params;
 764                 $this->call = $call;
 765                 $this->cmd = $cmd;
 766                 $this->chmodPath = $chmodPath;
 767         }
 768 }
 769
 770 /**
 771  * Wrapper around RecursiveDirectoryIterator/DirectoryIterator that
 772  * catches exception or does any custom behavoir that we may want.
 773  * Do not use this class from places outside FSFileBackend.
 774  *
 775  * @ingroup FileBackend
 776  */
 777 abstract class FSFileBackendList implements Iterator {
 778         /** @var Iterator */
 779         protected $iter;
 780         protected $suffixStart; // integer
 781         protected $pos = 0; // integer
 782         /** @var Array */
 783         protected $params = array();
 784
 785         /**
 786          * @param $dir string file system directory
 787          */
 788         public function __construct( $dir, array $params ) {
 789                 $dir = realpath( $dir ); // normalize
 790                 $this->suffixStart = strlen( $dir ) + 1; // size of "path/to/dir/"
 791                 $this->params = $params;
 792
 793                 try {
 794                         $this->iter = $this->initIterator( $dir );
 795                 } catch ( UnexpectedValueException $e ) {
 796                         $this->iter = null; // bad permissions? deleted?
 797                 }
 798         }
 799
 800         /**
 801          * Return an appropriate iterator object to wrap
 802          *
 803          * @param $dir string file system directory
 804          * @return Iterator
 805          */
 806         protected function initIterator( $dir ) {
 807                 if ( !empty( $this->params['topOnly'] ) ) { // non-recursive
 808                         # Get an iterator that will get direct sub-nodes
 809                         return new DirectoryIterator( $dir );
 810                 } else { // recursive
 811                         # Get an iterator that will return leaf nodes (non-directories)
 812                         # RecursiveDirectoryIterator extends FilesystemIterator.
 813                         # FilesystemIterator::SKIP_DOTS default is inconsistent in PHP 5.3.x.
 814                         $flags = FilesystemIterator::CURRENT_AS_SELF | FilesystemIterator::SKIP_DOTS;
 815                         return new RecursiveIteratorIterator(
 816                                 new RecursiveDirectoryIterator( $dir, $flags ),
 817                                 RecursiveIteratorIterator::CHILD_FIRST // include dirs
 818                         );
 819                 }
 820         }
 821
 822         /**
 823          * @see Iterator::key()
 824          * @return integer
 825          */
 826         public function key() {
 827                 return $this->pos;
 828         }
 829
 830         /**
 831          * @see Iterator::current()
 832          * @return string|bool String or false
 833          */
 834         public function current() {
 835                 return $this->getRelPath( $this->iter->current()->getPathname() );
 836         }
 837
 838         /**
 839          * @see Iterator::next()
 840          * @return void
 841          */
 842         public function next() {
 843                 try {
 844                         $this->iter->next();
 845                         $this->filterViaNext();
 846                 } catch ( UnexpectedValueException $e ) {
 847                         $this->iter = null;
 848                 }
 849                 ++$this->pos;
 850         }
 851
 852         /**
 853          * @see Iterator::rewind()
 854          * @return void
 855          */
 856         public function rewind() {
 857                 $this->pos = 0;
 858                 try {
 859                         $this->iter->rewind();
 860                         $this->filterViaNext();
 861                 } catch ( UnexpectedValueException $e ) {
 862                         $this->iter = null;
 863                 }
 864         }
 865
 866         /**
 867          * @see Iterator::valid()
 868          * @return bool
 869          */
 870         public function valid() {
 871                 return $this->iter && $this->iter->valid();
 872         }
 873
 874         /**
 875          * Filter out items by advancing to the next ones
 876          */
 877         protected function filterViaNext() {}
 878
 879         /**
 880          * Return only the relative path and normalize slashes to FileBackend-style.
 881          * Uses the "real path" since the suffix is based upon that.
 882          *
 883          * @param $path string
 884          * @return string
 885          */
 886         protected function getRelPath( $path ) {
 887                 return strtr( substr( realpath( $path ), $this->suffixStart ), '\\', '/' );
 888         }
 889 }
 890
 891 class FSFileBackendDirList extends FSFileBackendList {
 892         protected function filterViaNext() {
 893                 while ( $this->iter->valid() ) {
 894                         if ( $this->iter->current()->isDot() || !$this->iter->current()->isDir() ) {
 895                                 $this->iter->next(); // skip non-directories and dot files
 896                         } else {
 897                                 break;
 898                         }
 899                 }
 900         }
 901 }
 902
 903 class FSFileBackendFileList extends FSFileBackendList {
 904         protected function filterViaNext() {
 905                 while ( $this->iter->valid() ) {
 906                         if ( !$this->iter->current()->isFile() ) {
 907                                 $this->iter->next(); // skip non-files and dot files
 908                         } else {
 909                                 break;
 910                         }
 911                 }
 912         }
 913 }