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                 $ok = copy( $params['src'], $dest );
 195                 // In some cases (at least over NFS), copy() returns true when it fails.
 196                 if ( !$ok || ( filesize( $params['src'] ) !== filesize( $dest ) ) ) {
 197                         if ( $ok ) { // PHP bug
 198                                 unlink( $dest ); // remove broken file
 199                                 trigger_error( __METHOD__ . ": copy() failed but returned true." );
 200                         }
 201                         $status->fatal( 'backend-fail-store', $params['src'], $params['dst'] );
 202                         return $status;
 203                 }
 204
 205                 $this->chmod( $dest );
 206
 207                 return $status;
 208         }
 209
 210         /**
 211          * @see FileBackendStore::doCopyInternal()
 212          * @return Status
 213          */
 214         protected function doCopyInternal( array $params ) {
 215                 $status = Status::newGood();
 216
 217                 $source = $this->resolveToFSPath( $params['src'] );
 218                 if ( $source === null ) {
 219                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 220                         return $status;
 221                 }
 222
 223                 $dest = $this->resolveToFSPath( $params['dst'] );
 224                 if ( $dest === null ) {
 225                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 226                         return $status;
 227                 }
 228
 229                 if ( file_exists( $dest ) ) {
 230                         if ( !empty( $params['overwrite'] ) ) {
 231                                 $ok = unlink( $dest );
 232                                 if ( !$ok ) {
 233                                         $status->fatal( 'backend-fail-delete', $params['dst'] );
 234                                         return $status;
 235                                 }
 236                         } else {
 237                                 $status->fatal( 'backend-fail-alreadyexists', $params['dst'] );
 238                                 return $status;
 239                         }
 240                 }
 241
 242                 $ok = copy( $source, $dest );
 243                 // In some cases (at least over NFS), copy() returns true when it fails.
 244                 if ( !$ok || ( filesize( $source ) !== filesize( $dest ) ) ) {
 245                         if ( $ok ) { // PHP bug
 246                                 unlink( $dest ); // remove broken file
 247                                 trigger_error( __METHOD__ . ": copy() failed but returned true." );
 248                         }
 249                         $status->fatal( 'backend-fail-copy', $params['src'], $params['dst'] );
 250                         return $status;
 251                 }
 252
 253                 $this->chmod( $dest );
 254
 255                 return $status;
 256         }
 257
 258         /**
 259          * @see FileBackendStore::doMoveInternal()
 260          * @return Status
 261          */
 262         protected function doMoveInternal( array $params ) {
 263                 $status = Status::newGood();
 264
 265                 $source = $this->resolveToFSPath( $params['src'] );
 266                 if ( $source === null ) {
 267                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 268                         return $status;
 269                 }
 270
 271                 $dest = $this->resolveToFSPath( $params['dst'] );
 272                 if ( $dest === null ) {
 273                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 274                         return $status;
 275                 }
 276
 277                 if ( file_exists( $dest ) ) {
 278                         if ( !empty( $params['overwrite'] ) ) {
 279                                 // Windows does not support moving over existing files
 280                                 if ( wfIsWindows() ) {
 281                                         $ok = unlink( $dest );
 282                                         if ( !$ok ) {
 283                                                 $status->fatal( 'backend-fail-delete', $params['dst'] );
 284                                                 return $status;
 285                                         }
 286                                 }
 287                         } else {
 288                                 $status->fatal( 'backend-fail-alreadyexists', $params['dst'] );
 289                                 return $status;
 290                         }
 291                 }
 292
 293                 $ok = rename( $source, $dest );
 294                 clearstatcache(); // file no longer at source
 295                 if ( !$ok ) {
 296                         $status->fatal( 'backend-fail-move', $params['src'], $params['dst'] );
 297                         return $status;
 298                 }
 299
 300                 return $status;
 301         }
 302
 303         /**
 304          * @see FileBackendStore::doDeleteInternal()
 305          * @return Status
 306          */
 307         protected function doDeleteInternal( array $params ) {
 308                 $status = Status::newGood();
 309
 310                 $source = $this->resolveToFSPath( $params['src'] );
 311                 if ( $source === null ) {
 312                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 313                         return $status;
 314                 }
 315
 316                 if ( !is_file( $source ) ) {
 317                         if ( empty( $params['ignoreMissingSource'] ) ) {
 318                                 $status->fatal( 'backend-fail-delete', $params['src'] );
 319                         }
 320                         return $status; // do nothing; either OK or bad status
 321                 }
 322
 323                 $ok = unlink( $source );
 324                 if ( !$ok ) {
 325                         $status->fatal( 'backend-fail-delete', $params['src'] );
 326                         return $status;
 327                 }
 328
 329                 return $status;
 330         }
 331
 332         /**
 333          * @see FileBackendStore::doCreateInternal()
 334          * @return Status
 335          */
 336         protected function doCreateInternal( array $params ) {
 337                 $status = Status::newGood();
 338
 339                 $dest = $this->resolveToFSPath( $params['dst'] );
 340                 if ( $dest === null ) {
 341                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 342                         return $status;
 343                 }
 344
 345                 if ( file_exists( $dest ) ) {
 346                         if ( !empty( $params['overwrite'] ) ) {
 347                                 $ok = unlink( $dest );
 348                                 if ( !$ok ) {
 349                                         $status->fatal( 'backend-fail-delete', $params['dst'] );
 350                                         return $status;
 351                                 }
 352                         } else {
 353                                 $status->fatal( 'backend-fail-alreadyexists', $params['dst'] );
 354                                 return $status;
 355                         }
 356                 }
 357
 358                 $bytes = file_put_contents( $dest, $params['content'] );
 359                 if ( $bytes === false ) {
 360                         $status->fatal( 'backend-fail-create', $params['dst'] );
 361                         return $status;
 362                 }
 363
 364                 $this->chmod( $dest );
 365
 366                 return $status;
 367         }
 368
 369         /**
 370          * @see FileBackendStore::doPrepareInternal()
 371          * @return Status
 372          */
 373         protected function doPrepareInternal( $fullCont, $dirRel, array $params ) {
 374                 $status = Status::newGood();
 375                 list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
 376                 $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
 377                 $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
 378                 if ( !wfMkdirParents( $dir ) ) { // make directory and its parents
 379                         $status->fatal( 'directorycreateerror', $params['dir'] );
 380                 } elseif ( !is_writable( $dir ) ) {
 381                         $status->fatal( 'directoryreadonlyerror', $params['dir'] );
 382                 } elseif ( !is_readable( $dir ) ) {
 383                         $status->fatal( 'directorynotreadableerror', $params['dir'] );
 384                 }
 385                 return $status;
 386         }
 387
 388         /**
 389          * @see FileBackendStore::doSecureInternal()
 390          * @return Status
 391          */
 392         protected function doSecureInternal( $fullCont, $dirRel, array $params ) {
 393                 $status = Status::newGood();
 394                 list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
 395                 $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
 396                 $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
 397                 // Seed new directories with a blank index.html, to prevent crawling...
 398                 if ( !empty( $params['noListing'] ) && !file_exists( "{$dir}/index.html" ) ) {
 399                         $bytes = file_put_contents( "{$dir}/index.html", '' );
 400                         if ( !$bytes ) {
 401                                 $status->fatal( 'backend-fail-create', $params['dir'] . '/index.html' );
 402                                 return $status;
 403                         }
 404                 }
 405                 // Add a .htaccess file to the root of the container...
 406                 if ( !empty( $params['noAccess'] ) ) {
 407                         if ( !file_exists( "{$contRoot}/.htaccess" ) ) {
 408                                 $bytes = file_put_contents( "{$contRoot}/.htaccess", "Deny from all\n" );
 409                                 if ( !$bytes ) {
 410                                         $storeDir = "mwstore://{$this->name}/{$shortCont}";
 411                                         $status->fatal( 'backend-fail-create', "{$storeDir}/.htaccess" );
 412                                         return $status;
 413                                 }
 414                         }
 415                 }
 416                 return $status;
 417         }
 418
 419         /**
 420          * @see FileBackendStore::doCleanInternal()
 421          * @return Status
 422          */
 423         protected function doCleanInternal( $fullCont, $dirRel, array $params ) {
 424                 $status = Status::newGood();
 425                 list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
 426                 $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
 427                 $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
 428                 wfSuppressWarnings();
 429                 if ( is_dir( $dir ) ) {
 430                         rmdir( $dir ); // remove directory if empty
 431                 }
 432                 wfRestoreWarnings();
 433                 return $status;
 434         }
 435
 436         /**
 437          * @see FileBackendStore::doFileExists()
 438          * @return array|bool|null
 439          */
 440         protected function doGetFileStat( array $params ) {
 441                 $source = $this->resolveToFSPath( $params['src'] );
 442                 if ( $source === null ) {
 443                         return false; // invalid storage path
 444                 }
 445
 446                 $this->trapWarnings(); // don't trust 'false' if there were errors
 447                 $stat = is_file( $source ) ? stat( $source ) : false; // regular files only
 448                 $hadError = $this->untrapWarnings();
 449
 450                 if ( $stat ) {
 451                         return array(
 452                                 'mtime' => wfTimestamp( TS_MW, $stat['mtime'] ),
 453                                 'size'  => $stat['size']
 454                         );
 455                 } elseif ( !$hadError ) {
 456                         return false; // file does not exist
 457                 } else {
 458                         return null; // failure
 459                 }
 460         }
 461
 462         /**
 463          * @see FileBackendStore::doClearCache()
 464          */
 465         protected function doClearCache( array $paths = null ) {
 466                 clearstatcache(); // clear the PHP file stat cache
 467         }
 468
 469         /**
 470          * @see FileBackendStore::doDirectoryExists()
 471          * @return bool|null
 472          */
 473         protected function doDirectoryExists( $fullCont, $dirRel, array $params ) {
 474                 list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
 475                 $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
 476                 $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
 477
 478                 $this->trapWarnings(); // don't trust 'false' if there were errors
 479                 $exists = is_dir( $dir );
 480                 $hadError = $this->untrapWarnings();
 481
 482                 return $hadError ? null : $exists;
 483         }
 484
 485         /**
 486          * @see FileBackendStore::getDirectoryListInternal()
 487          * @return Array|null
 488          */
 489         public function getDirectoryListInternal( $fullCont, $dirRel, array $params ) {
 490                 list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
 491                 $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
 492                 $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
 493                 $exists = is_dir( $dir );
 494                 if ( !$exists ) {
 495                         wfDebug( __METHOD__ . "() given directory does not exist: '$dir'\n" );
 496                         return array(); // nothing under this dir
 497                 } elseif ( !is_readable( $dir ) ) {
 498                         wfDebug( __METHOD__ . "() given directory is unreadable: '$dir'\n" );
 499                         return null; // bad permissions?
 500                 }
 501                 return new FSFileBackendDirList( $dir, $params );
 502         }
 503
 504         /**
 505          * @see FileBackendStore::getFileListInternal()
 506          * @return array|FSFileBackendFileList|null
 507          */
 508         public function getFileListInternal( $fullCont, $dirRel, array $params ) {
 509                 list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
 510                 $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
 511                 $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
 512                 $exists = is_dir( $dir );
 513                 if ( !$exists ) {
 514                         wfDebug( __METHOD__ . "() given directory does not exist: '$dir'\n" );
 515                         return array(); // nothing under this dir
 516                 } elseif ( !is_readable( $dir ) ) {
 517                         wfDebug( __METHOD__ . "() given directory is unreadable: '$dir'\n" );
 518                         return null; // bad permissions?
 519                 }
 520                 return new FSFileBackendFileList( $dir, $params );
 521         }
 522
 523         /**
 524          * @see FileBackendStore::getLocalReference()
 525          * @return FSFile|null
 526          */
 527         public function getLocalReference( array $params ) {
 528                 $source = $this->resolveToFSPath( $params['src'] );
 529                 if ( $source === null ) {
 530                         return null;
 531                 }
 532                 return new FSFile( $source );
 533         }
 534
 535         /**
 536          * @see FileBackendStore::getLocalCopy()
 537          * @return null|TempFSFile
 538          */
 539         public function getLocalCopy( array $params ) {
 540                 $source = $this->resolveToFSPath( $params['src'] );
 541                 if ( $source === null ) {
 542                         return null;
 543                 }
 544
 545                 // Create a new temporary file with the same extension...
 546                 $ext = FileBackend::extensionFromPath( $params['src'] );
 547                 $tmpFile = TempFSFile::factory( wfBaseName( $source ) . '_', $ext );
 548                 if ( !$tmpFile ) {
 549                         return null;
 550                 }
 551                 $tmpPath = $tmpFile->getPath();
 552
 553                 // Copy the source file over the temp file
 554                 $ok = copy( $source, $tmpPath );
 555                 if ( !$ok ) {
 556                         return null;
 557                 }
 558
 559                 $this->chmod( $tmpPath );
 560
 561                 return $tmpFile;
 562         }
 563
 564         /**
 565          * @see FileBackendStore::directoriesAreVirtual()
 566          * @return bool
 567          */
 568         protected function directoriesAreVirtual() {
 569                 return false;
 570         }
 571
 572         /**
 573          * Chmod a file, suppressing the warnings
 574          *
 575          * @param $path string Absolute file system path
 576          * @return bool Success
 577          */
 578         protected function chmod( $path ) {
 579                 wfSuppressWarnings();
 580                 $ok = chmod( $path, $this->fileMode );
 581                 wfRestoreWarnings();
 582
 583                 return $ok;
 584         }
 585
 586         /**
 587          * Listen for E_WARNING errors and track whether any happen
 588          *
 589          * @return bool
 590          */
 591         protected function trapWarnings() {
 592                 $this->hadWarningErrors[] = false; // push to stack
 593                 set_error_handler( array( $this, 'handleWarning' ), E_WARNING );
 594                 return false; // invoke normal PHP error handler
 595         }
 596
 597         /**
 598          * Stop listening for E_WARNING errors and return true if any happened
 599          *
 600          * @return bool
 601          */
 602         protected function untrapWarnings() {
 603                 restore_error_handler(); // restore previous handler
 604                 return array_pop( $this->hadWarningErrors ); // pop from stack
 605         }
 606
 607         private function handleWarning() {
 608                 $this->hadWarningErrors[count( $this->hadWarningErrors ) - 1] = true;
 609                 return true; // suppress from PHP handler
 610         }
 611 }
 612
 613 /**
 614  * Wrapper around RecursiveDirectoryIterator/DirectoryIterator that
 615  * catches exception or does any custom behavoir that we may want.
 616  * Do not use this class from places outside FSFileBackend.
 617  *
 618  * @ingroup FileBackend
 619  */
 620 abstract class FSFileBackendList implements Iterator {
 621         /** @var Iterator */
 622         protected $iter;
 623         protected $suffixStart; // integer
 624         protected $pos = 0; // integer
 625         /** @var Array */
 626         protected $params = array();
 627
 628         /**
 629          * @param $dir string file system directory
 630          */
 631         public function __construct( $dir, array $params ) {
 632                 $dir = realpath( $dir ); // normalize
 633                 $this->suffixStart = strlen( $dir ) + 1; // size of "path/to/dir/"
 634                 $this->params = $params;
 635
 636                 try {
 637                         $this->iter = $this->initIterator( $dir );
 638                 } catch ( UnexpectedValueException $e ) {
 639                         $this->iter = null; // bad permissions? deleted?
 640                 }
 641         }
 642
 643         /**
 644          * Return an appropriate iterator object to wrap
 645          *
 646          * @param $dir string file system directory
 647          * @return Iterator
 648          */
 649         protected function initIterator( $dir ) {
 650                 if ( !empty( $this->params['topOnly'] ) ) { // non-recursive
 651                         # Get an iterator that will get direct sub-nodes
 652                         return new DirectoryIterator( $dir );
 653                 } else { // recursive
 654                         # Get an iterator that will return leaf nodes (non-directories)
 655                         # RecursiveDirectoryIterator extends FilesystemIterator.
 656                         # FilesystemIterator::SKIP_DOTS default is inconsistent in PHP 5.3.x.
 657                         $flags = FilesystemIterator::CURRENT_AS_SELF | FilesystemIterator::SKIP_DOTS;
 658                         return new RecursiveIteratorIterator(
 659                                 new RecursiveDirectoryIterator( $dir, $flags ),
 660                                 RecursiveIteratorIterator::CHILD_FIRST // include dirs
 661                         );
 662                 }
 663         }
 664
 665         /**
 666          * @see Iterator::key()
 667          * @return integer
 668          */
 669         public function key() {
 670                 return $this->pos;
 671         }
 672
 673         /**
 674          * @see Iterator::current()
 675          * @return string|bool String or false
 676          */
 677         public function current() {
 678                 return $this->getRelPath( $this->iter->current()->getPathname() );
 679         }
 680
 681         /**
 682          * @see Iterator::next()
 683          * @return void
 684          */
 685         public function next() {
 686                 try {
 687                         $this->iter->next();
 688                         $this->filterViaNext();
 689                 } catch ( UnexpectedValueException $e ) {
 690                         $this->iter = null;
 691                 }
 692                 ++$this->pos;
 693         }
 694
 695         /**
 696          * @see Iterator::rewind()
 697          * @return void
 698          */
 699         public function rewind() {
 700                 $this->pos = 0;
 701                 try {
 702                         $this->iter->rewind();
 703                         $this->filterViaNext();
 704                 } catch ( UnexpectedValueException $e ) {
 705                         $this->iter = null;
 706                 }
 707         }
 708
 709         /**
 710          * @see Iterator::valid()
 711          * @return bool
 712          */
 713         public function valid() {
 714                 return $this->iter && $this->iter->valid();
 715         }
 716
 717         /**
 718          * Filter out items by advancing to the next ones
 719          */
 720         protected function filterViaNext() {}
 721
 722         /**
 723          * Return only the relative path and normalize slashes to FileBackend-style.
 724          * Uses the "real path" since the suffix is based upon that.
 725          *
 726          * @param $path string
 727          * @return string
 728          */
 729         protected function getRelPath( $path ) {
 730                 return strtr( substr( realpath( $path ), $this->suffixStart ), '\\', '/' );
 731         }
 732 }
 733
 734 class FSFileBackendDirList extends FSFileBackendList {
 735         protected function filterViaNext() {
 736                 while ( $this->iter->valid() ) {
 737                         if ( $this->iter->current()->isDot() || !$this->iter->current()->isDir() ) {
 738                                 $this->iter->next(); // skip non-directories and dot files
 739                         } else {
 740                                 break;
 741                         }
 742                 }
 743         }
 744 }
 745
 746 class FSFileBackendFileList extends FSFileBackendList {
 747         protected function filterViaNext() {
 748                 while ( $this->iter->valid() ) {
 749                         if ( !$this->iter->current()->isFile() ) {
 750                                 $this->iter->next(); // skip non-files and dot files
 751                         } else {
 752                                 break;
 753                         }
 754                 }
 755         }
 756 }