includes/filebackend/SwiftFileBackend.php

   1 <?php
   2 /**
   3  * OpenStack Swift based file 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 Russ Nelson
  23  * @author Aaron Schulz
  24  */
  25
  26 /**
  27  * @brief Class for an OpenStack Swift (or Ceph RGW) based file backend.
  28  *
  29  * Status messages should avoid mentioning the Swift account name.
  30  * Likewise, error suppression should be used to avoid path disclosure.
  31  *
  32  * @ingroup FileBackend
  33  * @since 1.19
  34  */
  35 class SwiftFileBackend extends FileBackendStore {
  36         /** @var MultiHttpClient */
  37         protected $http;
  38
  39         /** @var int TTL in seconds */
  40         protected $authTTL;
  41
  42         /** @var string Authentication base URL (without version) */
  43         protected $swiftAuthUrl;
  44
  45         /** @var string Swift user (account:user) to authenticate as */
  46         protected $swiftUser;
  47
  48         /** @var string Secret key for user */
  49         protected $swiftKey;
  50
  51         /** @var string Shared secret value for making temp URLs */
  52         protected $swiftTempUrlKey;
  53
  54         /** @var string S3 access key (RADOS Gateway) */
  55         protected $rgwS3AccessKey;
  56
  57         /** @var string S3 authentication key (RADOS Gateway) */
  58         protected $rgwS3SecretKey;
  59
  60         /** @var BagOStuff */
  61         protected $srvCache;
  62
  63         /** @var ProcessCacheLRU Container stat cache */
  64         protected $containerStatCache;
  65
  66         /** @var array */
  67         protected $authCreds;
  68
  69         /** @var int UNIX timestamp */
  70         protected $authSessionTimestamp = 0;
  71
  72         /** @var int UNIX timestamp */
  73         protected $authErrorTimestamp = null;
  74
  75         /** @var bool Whether the server is an Ceph RGW */
  76         protected $isRGW = false;
  77
  78         /**
  79          * @see FileBackendStore::__construct()
  80          * Additional $config params include:
  81          *   - swiftAuthUrl       : Swift authentication server URL
  82          *   - swiftUser          : Swift user used by MediaWiki (account:username)
  83          *   - swiftKey           : Swift authentication key for the above user
  84          *   - swiftAuthTTL       : Swift authentication TTL (seconds)
  85          *   - swiftTempUrlKey    : Swift "X-Account-Meta-Temp-URL-Key" value on the account.
  86          *                          Do not set this until it has been set in the backend.
  87          *   - shardViaHashLevels : Map of container names to sharding config with:
  88          *                             - base   : base of hash characters, 16 or 36
  89          *                             - levels : the number of hash levels (and digits)
  90          *                             - repeat : hash subdirectories are prefixed with all the
  91          *                                        parent hash directory names (e.g. "a/ab/abc")
  92          *   - cacheAuthInfo      : Whether to cache authentication tokens in APC, XCache, ect.
  93          *                          If those are not available, then the main cache will be used.
  94          *                          This is probably insecure in shared hosting environments.
  95          *   - rgwS3AccessKey     : Rados Gateway S3 "access key" value on the account.
  96          *                          Do not set this until it has been set in the backend.
  97          *                          This is used for generating expiring pre-authenticated URLs.
  98          *                          Only use this when using rgw and to work around
  99          *                          http://tracker.newdream.net/issues/3454.
 100          *   - rgwS3SecretKey     : Rados Gateway S3 "secret key" value on the account.
 101          *                          Do not set this until it has been set in the backend.
 102          *                          This is used for generating expiring pre-authenticated URLs.
 103          *                          Only use this when using rgw and to work around
 104          *                          http://tracker.newdream.net/issues/3454.
 105          */
 106         public function __construct( array $config ) {
 107                 parent::__construct( $config );
 108                 // Required settings
 109                 $this->swiftAuthUrl = $config['swiftAuthUrl'];
 110                 $this->swiftUser = $config['swiftUser'];
 111                 $this->swiftKey = $config['swiftKey'];
 112                 // Optional settings
 113                 $this->authTTL = isset( $config['swiftAuthTTL'] )
 114                         ? $config['swiftAuthTTL']
 115                         : 15 * 60; // some sane number
 116                 $this->swiftTempUrlKey = isset( $config['swiftTempUrlKey'] )
 117                         ? $config['swiftTempUrlKey']
 118                         : '';
 119                 $this->shardViaHashLevels = isset( $config['shardViaHashLevels'] )
 120                         ? $config['shardViaHashLevels']
 121                         : '';
 122                 $this->rgwS3AccessKey = isset( $config['rgwS3AccessKey'] )
 123                         ? $config['rgwS3AccessKey']
 124                         : '';
 125                 $this->rgwS3SecretKey = isset( $config['rgwS3SecretKey'] )
 126                         ? $config['rgwS3SecretKey']
 127                         : '';
 128                 // HTTP helper client
 129                 $this->http = new MultiHttpClient( array() );
 130                 // Cache container information to mask latency
 131                 if ( isset( $config['wanCache'] ) && $config['wanCache'] instanceof WANObjectCache ) {
 132                         $this->memCache = $config['wanCache'];
 133                 }
 134                 // Process cache for container info
 135                 $this->containerStatCache = new ProcessCacheLRU( 300 );
 136                 // Cache auth token information to avoid RTTs
 137                 if ( !empty( $config['cacheAuthInfo'] ) ) {
 138                         if ( PHP_SAPI === 'cli' ) {
 139                                 $this->srvCache = wfGetMainCache(); // preferrably memcached
 140                         } else {
 141                                 try { // look for APC, XCache, WinCache, ect...
 142                                         $this->srvCache = ObjectCache::newAccelerator( array() );
 143                                 } catch ( Exception $e ) {
 144                                 }
 145                         }
 146                 }
 147                 $this->srvCache = $this->srvCache ?: new EmptyBagOStuff();
 148         }
 149
 150         public function getFeatures() {
 151                 return ( FileBackend::ATTR_UNICODE_PATHS |
 152                         FileBackend::ATTR_HEADERS | FileBackend::ATTR_METADATA );
 153         }
 154
 155         protected function resolveContainerPath( $container, $relStoragePath ) {
 156                 if ( !mb_check_encoding( $relStoragePath, 'UTF-8' ) ) { // mb_string required by CF
 157                         return null; // not UTF-8, makes it hard to use CF and the swift HTTP API
 158                 } elseif ( strlen( urlencode( $relStoragePath ) ) > 1024 ) {
 159                         return null; // too long for Swift
 160                 }
 161
 162                 return $relStoragePath;
 163         }
 164
 165         public function isPathUsableInternal( $storagePath ) {
 166                 list( $container, $rel ) = $this->resolveStoragePathReal( $storagePath );
 167                 if ( $rel === null ) {
 168                         return false; // invalid
 169                 }
 170
 171                 return is_array( $this->getContainerStat( $container ) );
 172         }
 173
 174         /**
 175          * Sanitize and filter the custom headers from a $params array.
 176          * Only allows certain "standard" Content- and X-Content- headers.
 177          *
 178          * @param array $params
 179          * @return array Sanitized value of 'headers' field in $params
 180          */
 181         protected function sanitizeHdrs( array $params ) {
 182                 return isset( $params['headers'] )
 183                         ? $this->getCustomHeaders( $params['headers'] )
 184                         : array();
 185
 186         }
 187
 188         /**
 189          * @param array $rawHeaders
 190          * @return array Custom non-metadata HTTP headers
 191          */
 192         protected function getCustomHeaders( array $rawHeaders ) {
 193                 $headers = array();
 194
 195                 // Normalize casing, and strip out illegal headers
 196                 foreach ( $rawHeaders as $name => $value ) {
 197                         $name = strtolower( $name );
 198                         if ( preg_match( '/^content-(type|length)$/', $name ) ) {
 199                                 continue; // blacklisted
 200                         } elseif ( preg_match( '/^(x-)?content-/', $name ) ) {
 201                                 $headers[$name] = $value; // allowed
 202                         } elseif ( preg_match( '/^content-(disposition)/', $name ) ) {
 203                                 $headers[$name] = $value; // allowed
 204                         }
 205                 }
 206                 // By default, Swift has annoyingly low maximum header value limits
 207                 if ( isset( $headers['content-disposition'] ) ) {
 208                         $disposition = '';
 209                         // @note: assume FileBackend::makeContentDisposition() already used
 210                         foreach ( explode( ';', $headers['content-disposition'] ) as $part ) {
 211                                 $part = trim( $part );
 212                                 $new = ( $disposition === '' ) ? $part : "{$disposition};{$part}";
 213                                 if ( strlen( $new ) <= 255 ) {
 214                                         $disposition = $new;
 215                                 } else {
 216                                         break; // too long; sigh
 217                                 }
 218                         }
 219                         $headers['content-disposition'] = $disposition;
 220                 }
 221
 222                 return $headers;
 223         }
 224
 225         /**
 226          * @param array $rawHeaders
 227          * @return array Custom metadata headers
 228          */
 229         protected function getMetadataHeaders( array $rawHeaders ) {
 230                 $headers = array();
 231                 foreach ( $rawHeaders as $name => $value ) {
 232                         $name = strtolower( $name );
 233                         if ( strpos( $name, 'x-object-meta-' ) === 0 ) {
 234                                 $headers[$name] = $value;
 235                         }
 236                 }
 237
 238                 return $headers;
 239         }
 240
 241         /**
 242          * @param array $rawHeaders
 243          * @return array Custom metadata headers with prefix removed
 244          */
 245         protected function getMetadata( array $rawHeaders ) {
 246                 $metadata = array();
 247                 foreach ( $this->getMetadataHeaders( $rawHeaders ) as $name => $value ) {
 248                         $metadata[substr( $name, strlen( 'x-object-meta-' ) )] = $value;
 249                 }
 250
 251                 return $metadata;
 252         }
 253
 254         protected function doCreateInternal( array $params ) {
 255                 $status = Status::newGood();
 256
 257                 list( $dstCont, $dstRel ) = $this->resolveStoragePathReal( $params['dst'] );
 258                 if ( $dstRel === null ) {
 259                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 260
 261                         return $status;
 262                 }
 263
 264                 $sha1Hash = wfBaseConvert( sha1( $params['content'] ), 16, 36, 31 );
 265                 $contentType = $this->getContentType( $params['dst'], $params['content'], null );
 266
 267                 $reqs = array( array(
 268                         'method' => 'PUT',
 269                         'url' => array( $dstCont, $dstRel ),
 270                         'headers' => array(
 271                                 'content-length' => strlen( $params['content'] ),
 272                                 'etag' => md5( $params['content'] ),
 273                                 'content-type' => $contentType,
 274                                 'x-object-meta-sha1base36' => $sha1Hash
 275                         ) + $this->sanitizeHdrs( $params ),
 276                         'body' => $params['content']
 277                 ) );
 278
 279                 $that = $this;
 280                 $method = __METHOD__;
 281                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 282                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 283                         if ( $rcode === 201 ) {
 284                                 // good
 285                         } elseif ( $rcode === 412 ) {
 286                                 $status->fatal( 'backend-fail-contenttype', $params['dst'] );
 287                         } else {
 288                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 289                         }
 290                 };
 291
 292                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 293                 if ( !empty( $params['async'] ) ) { // deferred
 294                         $status->value = $opHandle;
 295                 } else { // actually write the object in Swift
 296                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 297                 }
 298
 299                 return $status;
 300         }
 301
 302         protected function doStoreInternal( array $params ) {
 303                 $status = Status::newGood();
 304
 305                 list( $dstCont, $dstRel ) = $this->resolveStoragePathReal( $params['dst'] );
 306                 if ( $dstRel === null ) {
 307                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 308
 309                         return $status;
 310                 }
 311
 312                 MediaWiki\suppressWarnings();
 313                 $sha1Hash = sha1_file( $params['src'] );
 314                 MediaWiki\restoreWarnings();
 315                 if ( $sha1Hash === false ) { // source doesn't exist?
 316                         $status->fatal( 'backend-fail-store', $params['src'], $params['dst'] );
 317
 318                         return $status;
 319                 }
 320                 $sha1Hash = wfBaseConvert( $sha1Hash, 16, 36, 31 );
 321                 $contentType = $this->getContentType( $params['dst'], null, $params['src'] );
 322
 323                 $handle = fopen( $params['src'], 'rb' );
 324                 if ( $handle === false ) { // source doesn't exist?
 325                         $status->fatal( 'backend-fail-store', $params['src'], $params['dst'] );
 326
 327                         return $status;
 328                 }
 329
 330                 $reqs = array( array(
 331                         'method' => 'PUT',
 332                         'url' => array( $dstCont, $dstRel ),
 333                         'headers' => array(
 334                                 'content-length' => filesize( $params['src'] ),
 335                                 'etag' => md5_file( $params['src'] ),
 336                                 'content-type' => $contentType,
 337                                 'x-object-meta-sha1base36' => $sha1Hash
 338                         ) + $this->sanitizeHdrs( $params ),
 339                         'body' => $handle // resource
 340                 ) );
 341
 342                 $that = $this;
 343                 $method = __METHOD__;
 344                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 345                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 346                         if ( $rcode === 201 ) {
 347                                 // good
 348                         } elseif ( $rcode === 412 ) {
 349                                 $status->fatal( 'backend-fail-contenttype', $params['dst'] );
 350                         } else {
 351                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 352                         }
 353                 };
 354
 355                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 356                 if ( !empty( $params['async'] ) ) { // deferred
 357                         $status->value = $opHandle;
 358                 } else { // actually write the object in Swift
 359                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 360                 }
 361
 362                 return $status;
 363         }
 364
 365         protected function doCopyInternal( array $params ) {
 366                 $status = Status::newGood();
 367
 368                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
 369                 if ( $srcRel === null ) {
 370                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 371
 372                         return $status;
 373                 }
 374
 375                 list( $dstCont, $dstRel ) = $this->resolveStoragePathReal( $params['dst'] );
 376                 if ( $dstRel === null ) {
 377                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 378
 379                         return $status;
 380                 }
 381
 382                 $reqs = array( array(
 383                         'method' => 'PUT',
 384                         'url' => array( $dstCont, $dstRel ),
 385                         'headers' => array(
 386                                 'x-copy-from' => '/' . rawurlencode( $srcCont ) .
 387                                         '/' . str_replace( "%2F", "/", rawurlencode( $srcRel ) )
 388                         ) + $this->sanitizeHdrs( $params ), // extra headers merged into object
 389                 ) );
 390
 391                 $that = $this;
 392                 $method = __METHOD__;
 393                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 394                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 395                         if ( $rcode === 201 ) {
 396                                 // good
 397                         } elseif ( $rcode === 404 ) {
 398                                 $status->fatal( 'backend-fail-copy', $params['src'], $params['dst'] );
 399                         } else {
 400                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 401                         }
 402                 };
 403
 404                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 405                 if ( !empty( $params['async'] ) ) { // deferred
 406                         $status->value = $opHandle;
 407                 } else { // actually write the object in Swift
 408                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 409                 }
 410
 411                 return $status;
 412         }
 413
 414         protected function doMoveInternal( array $params ) {
 415                 $status = Status::newGood();
 416
 417                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
 418                 if ( $srcRel === null ) {
 419                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 420
 421                         return $status;
 422                 }
 423
 424                 list( $dstCont, $dstRel ) = $this->resolveStoragePathReal( $params['dst'] );
 425                 if ( $dstRel === null ) {
 426                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 427
 428                         return $status;
 429                 }
 430
 431                 $reqs = array(
 432                         array(
 433                                 'method' => 'PUT',
 434                                 'url' => array( $dstCont, $dstRel ),
 435                                 'headers' => array(
 436                                         'x-copy-from' => '/' . rawurlencode( $srcCont ) .
 437                                                 '/' . str_replace( "%2F", "/", rawurlencode( $srcRel ) )
 438                                 ) + $this->sanitizeHdrs( $params ) // extra headers merged into object
 439                         )
 440                 );
 441                 if ( "{$srcCont}/{$srcRel}" !== "{$dstCont}/{$dstRel}" ) {
 442                         $reqs[] = array(
 443                                 'method' => 'DELETE',
 444                                 'url' => array( $srcCont, $srcRel ),
 445                                 'headers' => array()
 446                         );
 447                 }
 448
 449                 $that = $this;
 450                 $method = __METHOD__;
 451                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 452                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 453                         if ( $request['method'] === 'PUT' && $rcode === 201 ) {
 454                                 // good
 455                         } elseif ( $request['method'] === 'DELETE' && $rcode === 204 ) {
 456                                 // good
 457                         } elseif ( $rcode === 404 ) {
 458                                 $status->fatal( 'backend-fail-move', $params['src'], $params['dst'] );
 459                         } else {
 460                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 461                         }
 462                 };
 463
 464                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 465                 if ( !empty( $params['async'] ) ) { // deferred
 466                         $status->value = $opHandle;
 467                 } else { // actually move the object in Swift
 468                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 469                 }
 470
 471                 return $status;
 472         }
 473
 474         protected function doDeleteInternal( array $params ) {
 475                 $status = Status::newGood();
 476
 477                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
 478                 if ( $srcRel === null ) {
 479                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 480
 481                         return $status;
 482                 }
 483
 484                 $reqs = array( array(
 485                         'method' => 'DELETE',
 486                         'url' => array( $srcCont, $srcRel ),
 487                         'headers' => array()
 488                 ) );
 489
 490                 $that = $this;
 491                 $method = __METHOD__;
 492                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 493                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 494                         if ( $rcode === 204 ) {
 495                                 // good
 496                         } elseif ( $rcode === 404 ) {
 497                                 if ( empty( $params['ignoreMissingSource'] ) ) {
 498                                         $status->fatal( 'backend-fail-delete', $params['src'] );
 499                                 }
 500                         } else {
 501                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 502                         }
 503                 };
 504
 505                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 506                 if ( !empty( $params['async'] ) ) { // deferred
 507                         $status->value = $opHandle;
 508                 } else { // actually delete the object in Swift
 509                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 510                 }
 511
 512                 return $status;
 513         }
 514
 515         protected function doDescribeInternal( array $params ) {
 516                 $status = Status::newGood();
 517
 518                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
 519                 if ( $srcRel === null ) {
 520                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 521
 522                         return $status;
 523                 }
 524
 525                 // Fetch the old object headers/metadata...this should be in stat cache by now
 526                 $stat = $this->getFileStat( array( 'src' => $params['src'], 'latest' => 1 ) );
 527                 if ( $stat && !isset( $stat['xattr'] ) ) { // older cache entry
 528                         $stat = $this->doGetFileStat( array( 'src' => $params['src'], 'latest' => 1 ) );
 529                 }
 530                 if ( !$stat ) {
 531                         $status->fatal( 'backend-fail-describe', $params['src'] );
 532
 533                         return $status;
 534                 }
 535
 536                 // POST clears prior headers, so we need to merge the changes in to the old ones
 537                 $metaHdrs = array();
 538                 foreach ( $stat['xattr']['metadata'] as $name => $value ) {
 539                         $metaHdrs["x-object-meta-$name"] = $value;
 540                 }
 541                 $customHdrs = $this->sanitizeHdrs( $params ) + $stat['xattr']['headers'];
 542
 543                 $reqs = array( array(
 544                         'method' => 'POST',
 545                         'url' => array( $srcCont, $srcRel ),
 546                         'headers' => $metaHdrs + $customHdrs
 547                 ) );
 548
 549                 $that = $this;
 550                 $method = __METHOD__;
 551                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 552                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 553                         if ( $rcode === 202 ) {
 554                                 // good
 555                         } elseif ( $rcode === 404 ) {
 556                                 $status->fatal( 'backend-fail-describe', $params['src'] );
 557                         } else {
 558                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 559                         }
 560                 };
 561
 562                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 563                 if ( !empty( $params['async'] ) ) { // deferred
 564                         $status->value = $opHandle;
 565                 } else { // actually change the object in Swift
 566                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 567                 }
 568
 569                 return $status;
 570         }
 571
 572         protected function doPrepareInternal( $fullCont, $dir, array $params ) {
 573                 $status = Status::newGood();
 574
 575                 // (a) Check if container already exists
 576                 $stat = $this->getContainerStat( $fullCont );
 577                 if ( is_array( $stat ) ) {
 578                         return $status; // already there
 579                 } elseif ( $stat === null ) {
 580                         $status->fatal( 'backend-fail-internal', $this->name );
 581                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': cannot get container stat' );
 582
 583                         return $status;
 584                 }
 585
 586                 // (b) Create container as needed with proper ACLs
 587                 if ( $stat === false ) {
 588                         $params['op'] = 'prepare';
 589                         $status->merge( $this->createContainer( $fullCont, $params ) );
 590                 }
 591
 592                 return $status;
 593         }
 594
 595         protected function doSecureInternal( $fullCont, $dir, array $params ) {
 596                 $status = Status::newGood();
 597                 if ( empty( $params['noAccess'] ) ) {
 598                         return $status; // nothing to do
 599                 }
 600
 601                 $stat = $this->getContainerStat( $fullCont );
 602                 if ( is_array( $stat ) ) {
 603                         // Make container private to end-users...
 604                         $status->merge( $this->setContainerAccess(
 605                                 $fullCont,
 606                                 array( $this->swiftUser ), // read
 607                                 array( $this->swiftUser ) // write
 608                         ) );
 609                 } elseif ( $stat === false ) {
 610                         $status->fatal( 'backend-fail-usable', $params['dir'] );
 611                 } else {
 612                         $status->fatal( 'backend-fail-internal', $this->name );
 613                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': cannot get container stat' );
 614                 }
 615
 616                 return $status;
 617         }
 618
 619         protected function doPublishInternal( $fullCont, $dir, array $params ) {
 620                 $status = Status::newGood();
 621
 622                 $stat = $this->getContainerStat( $fullCont );
 623                 if ( is_array( $stat ) ) {
 624                         // Make container public to end-users...
 625                         $status->merge( $this->setContainerAccess(
 626                                 $fullCont,
 627                                 array( $this->swiftUser, '.r:*' ), // read
 628                                 array( $this->swiftUser ) // write
 629                         ) );
 630                 } elseif ( $stat === false ) {
 631                         $status->fatal( 'backend-fail-usable', $params['dir'] );
 632                 } else {
 633                         $status->fatal( 'backend-fail-internal', $this->name );
 634                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': cannot get container stat' );
 635                 }
 636
 637                 return $status;
 638         }
 639
 640         protected function doCleanInternal( $fullCont, $dir, array $params ) {
 641                 $status = Status::newGood();
 642
 643                 // Only containers themselves can be removed, all else is virtual
 644                 if ( $dir != '' ) {
 645                         return $status; // nothing to do
 646                 }
 647
 648                 // (a) Check the container
 649                 $stat = $this->getContainerStat( $fullCont, true );
 650                 if ( $stat === false ) {
 651                         return $status; // ok, nothing to do
 652                 } elseif ( !is_array( $stat ) ) {
 653                         $status->fatal( 'backend-fail-internal', $this->name );
 654                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': cannot get container stat' );
 655
 656                         return $status;
 657                 }
 658
 659                 // (b) Delete the container if empty
 660                 if ( $stat['count'] == 0 ) {
 661                         $params['op'] = 'clean';
 662                         $status->merge( $this->deleteContainer( $fullCont, $params ) );
 663                 }
 664
 665                 return $status;
 666         }
 667
 668         protected function doGetFileStat( array $params ) {
 669                 $params = array( 'srcs' => array( $params['src'] ), 'concurrency' => 1 ) + $params;
 670                 unset( $params['src'] );
 671                 $stats = $this->doGetFileStatMulti( $params );
 672
 673                 return reset( $stats );
 674         }
 675
 676         /**
 677          * Convert dates like "Tue, 03 Jan 2012 22:01:04 GMT"/"2013-05-11T07:37:27.678360Z".
 678          * Dates might also come in like "2013-05-11T07:37:27.678360" from Swift listings,
 679          * missing the timezone suffix (though Ceph RGW does not appear to have this bug).
 680          *
 681          * @param string $ts
 682          * @param int $format Output format (TS_* constant)
 683          * @return string
 684          * @throws FileBackendError
 685          */
 686         protected function convertSwiftDate( $ts, $format = TS_MW ) {
 687                 try {
 688                         $timestamp = new MWTimestamp( $ts );
 689
 690                         return $timestamp->getTimestamp( $format );
 691                 } catch ( Exception $e ) {
 692                         throw new FileBackendError( $e->getMessage() );
 693                 }
 694         }
 695
 696         /**
 697          * Fill in any missing object metadata and save it to Swift
 698          *
 699          * @param array $objHdrs Object response headers
 700          * @param string $path Storage path to object
 701          * @return array New headers
 702          */
 703         protected function addMissingMetadata( array $objHdrs, $path ) {
 704                 if ( isset( $objHdrs['x-object-meta-sha1base36'] ) ) {
 705                         return $objHdrs; // nothing to do
 706                 }
 707
 708                 /** @noinspection PhpUnusedLocalVariableInspection */
 709                 $ps = Profiler::instance()->scopedProfileIn( __METHOD__ . "-{$this->name}" );
 710                 wfDebugLog( 'SwiftBackend', __METHOD__ . ": $path was not stored with SHA-1 metadata." );
 711
 712                 $objHdrs['x-object-meta-sha1base36'] = false;
 713
 714                 $auth = $this->getAuthentication();
 715                 if ( !$auth ) {
 716                         return $objHdrs; // failed
 717                 }
 718
 719                 $status = Status::newGood();
 720                 /** @noinspection PhpUnusedLocalVariableInspection */
 721                 $scopeLockS = $this->getScopedFileLocks( array( $path ), LockManager::LOCK_UW, $status );
 722                 if ( $status->isOK() ) {
 723                         $tmpFile = $this->getLocalCopy( array( 'src' => $path, 'latest' => 1 ) );
 724                         if ( $tmpFile ) {
 725                                 $hash = $tmpFile->getSha1Base36();
 726                                 if ( $hash !== false ) {
 727                                         $objHdrs['x-object-meta-sha1base36'] = $hash;
 728                                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
 729                                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
 730                                                 'method' => 'POST',
 731                                                 'url' => $this->storageUrl( $auth, $srcCont, $srcRel ),
 732                                                 'headers' => $this->authTokenHeaders( $auth ) + $objHdrs
 733                                         ) );
 734                                         if ( $rcode >= 200 && $rcode <= 299 ) {
 735                                                 $this->deleteFileCache( $path );
 736
 737                                                 return $objHdrs; // success
 738                                         }
 739                                 }
 740                         }
 741                 }
 742
 743                 wfDebugLog( 'SwiftBackend', __METHOD__ . ": unable to set SHA-1 metadata for $path" );
 744
 745                 return $objHdrs; // failed
 746         }
 747
 748         protected function doGetFileContentsMulti( array $params ) {
 749                 $contents = array();
 750
 751                 $auth = $this->getAuthentication();
 752
 753                 $ep = array_diff_key( $params, array( 'srcs' => 1 ) ); // for error logging
 754                 // Blindly create tmp files and stream to them, catching any exception if the file does
 755                 // not exist. Doing stats here is useless and will loop infinitely in addMissingMetadata().
 756                 $reqs = array(); // (path => op)
 757
 758                 foreach ( $params['srcs'] as $path ) { // each path in this concurrent batch
 759                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
 760                         if ( $srcRel === null || !$auth ) {
 761                                 $contents[$path] = false;
 762                                 continue;
 763                         }
 764                         // Create a new temporary memory file...
 765                         $handle = fopen( 'php://temp', 'wb' );
 766                         if ( $handle ) {
 767                                 $reqs[$path] = array(
 768                                         'method'  => 'GET',
 769                                         'url'     => $this->storageUrl( $auth, $srcCont, $srcRel ),
 770                                         'headers' => $this->authTokenHeaders( $auth )
 771                                                 + $this->headersFromParams( $params ),
 772                                         'stream'  => $handle,
 773                                 );
 774                         }
 775                         $contents[$path] = false;
 776                 }
 777
 778                 $opts = array( 'maxConnsPerHost' => $params['concurrency'] );
 779                 $reqs = $this->http->runMulti( $reqs, $opts );
 780                 foreach ( $reqs as $path => $op ) {
 781                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $op['response'];
 782                         if ( $rcode >= 200 && $rcode <= 299 ) {
 783                                 rewind( $op['stream'] ); // start from the beginning
 784                                 $contents[$path] = stream_get_contents( $op['stream'] );
 785                         } elseif ( $rcode === 404 ) {
 786                                 $contents[$path] = false;
 787                         } else {
 788                                 $this->onError( null, __METHOD__,
 789                                         array( 'src' => $path ) + $ep, $rerr, $rcode, $rdesc );
 790                         }
 791                         fclose( $op['stream'] ); // close open handle
 792                 }
 793
 794                 return $contents;
 795         }
 796
 797         protected function doDirectoryExists( $fullCont, $dir, array $params ) {
 798                 $prefix = ( $dir == '' ) ? null : "{$dir}/";
 799                 $status = $this->objectListing( $fullCont, 'names', 1, null, $prefix );
 800                 if ( $status->isOk() ) {
 801                         return ( count( $status->value ) ) > 0;
 802                 }
 803
 804                 return null; // error
 805         }
 806
 807         /**
 808          * @see FileBackendStore::getDirectoryListInternal()
 809          * @param string $fullCont
 810          * @param string $dir
 811          * @param array $params
 812          * @return SwiftFileBackendDirList
 813          */
 814         public function getDirectoryListInternal( $fullCont, $dir, array $params ) {
 815                 return new SwiftFileBackendDirList( $this, $fullCont, $dir, $params );
 816         }
 817
 818         /**
 819          * @see FileBackendStore::getFileListInternal()
 820          * @param string $fullCont
 821          * @param string $dir
 822          * @param array $params
 823          * @return SwiftFileBackendFileList
 824          */
 825         public function getFileListInternal( $fullCont, $dir, array $params ) {
 826                 return new SwiftFileBackendFileList( $this, $fullCont, $dir, $params );
 827         }
 828
 829         /**
 830          * Do not call this function outside of SwiftFileBackendFileList
 831          *
 832          * @param string $fullCont Resolved container name
 833          * @param string $dir Resolved storage directory with no trailing slash
 834          * @param string|null $after Resolved container relative path to list items after
 835          * @param int $limit Max number of items to list
 836          * @param array $params Parameters for getDirectoryList()
 837          * @return array List of container relative resolved paths of directories directly under $dir
 838          * @throws FileBackendError
 839          */
 840         public function getDirListPageInternal( $fullCont, $dir, &$after, $limit, array $params ) {
 841                 $dirs = array();
 842                 if ( $after === INF ) {
 843                         return $dirs; // nothing more
 844                 }
 845
 846                 $ps = Profiler::instance()->scopedProfileIn( __METHOD__ . "-{$this->name}" );
 847
 848                 $prefix = ( $dir == '' ) ? null : "{$dir}/";
 849                 // Non-recursive: only list dirs right under $dir
 850                 if ( !empty( $params['topOnly'] ) ) {
 851                         $status = $this->objectListing( $fullCont, 'names', $limit, $after, $prefix, '/' );
 852                         if ( !$status->isOk() ) {
 853                                 return $dirs; // error
 854                         }
 855                         $objects = $status->value;
 856                         foreach ( $objects as $object ) { // files and directories
 857                                 if ( substr( $object, -1 ) === '/' ) {
 858                                         $dirs[] = $object; // directories end in '/'
 859                                 }
 860                         }
 861                 } else {
 862                         // Recursive: list all dirs under $dir and its subdirs
 863                         $getParentDir = function ( $path ) {
 864                                 return ( strpos( $path, '/' ) !== false ) ? dirname( $path ) : false;
 865                         };
 866
 867                         // Get directory from last item of prior page
 868                         $lastDir = $getParentDir( $after ); // must be first page
 869                         $status = $this->objectListing( $fullCont, 'names', $limit, $after, $prefix );
 870
 871                         if ( !$status->isOk() ) {
 872                                 return $dirs; // error
 873                         }
 874
 875                         $objects = $status->value;
 876
 877                         foreach ( $objects as $object ) { // files
 878                                 $objectDir = $getParentDir( $object ); // directory of object
 879
 880                                 if ( $objectDir !== false && $objectDir !== $dir ) {
 881                                         // Swift stores paths in UTF-8, using binary sorting.
 882                                         // See function "create_container_table" in common/db.py.
 883                                         // If a directory is not "greater" than the last one,
 884                                         // then it was already listed by the calling iterator.
 885                                         if ( strcmp( $objectDir, $lastDir ) > 0 ) {
 886                                                 $pDir = $objectDir;
 887                                                 do { // add dir and all its parent dirs
 888                                                         $dirs[] = "{$pDir}/";
 889                                                         $pDir = $getParentDir( $pDir );
 890                                                 } while ( $pDir !== false // sanity
 891                                                         && strcmp( $pDir, $lastDir ) > 0 // not done already
 892                                                         && strlen( $pDir ) > strlen( $dir ) // within $dir
 893                                                 );
 894                                         }
 895                                         $lastDir = $objectDir;
 896                                 }
 897                         }
 898                 }
 899                 // Page on the unfiltered directory listing (what is returned may be filtered)
 900                 if ( count( $objects ) < $limit ) {
 901                         $after = INF; // avoid a second RTT
 902                 } else {
 903                         $after = end( $objects ); // update last item
 904                 }
 905
 906                 return $dirs;
 907         }
 908
 909         /**
 910          * Do not call this function outside of SwiftFileBackendFileList
 911          *
 912          * @param string $fullCont Resolved container name
 913          * @param string $dir Resolved storage directory with no trailing slash
 914          * @param string|null $after Resolved container relative path of file to list items after
 915          * @param int $limit Max number of items to list
 916          * @param array $params Parameters for getDirectoryList()
 917          * @return array List of resolved container relative paths of files under $dir
 918          * @throws FileBackendError
 919          */
 920         public function getFileListPageInternal( $fullCont, $dir, &$after, $limit, array $params ) {
 921                 $files = array(); // list of (path, stat array or null) entries
 922                 if ( $after === INF ) {
 923                         return $files; // nothing more
 924                 }
 925
 926                 $ps = Profiler::instance()->scopedProfileIn( __METHOD__ . "-{$this->name}" );
 927
 928                 $prefix = ( $dir == '' ) ? null : "{$dir}/";
 929                 // $objects will contain a list of unfiltered names or CF_Object items
 930                 // Non-recursive: only list files right under $dir
 931                 if ( !empty( $params['topOnly'] ) ) {
 932                         if ( !empty( $params['adviseStat'] ) ) {
 933                                 $status = $this->objectListing( $fullCont, 'info', $limit, $after, $prefix, '/' );
 934                         } else {
 935                                 $status = $this->objectListing( $fullCont, 'names', $limit, $after, $prefix, '/' );
 936                         }
 937                 } else {
 938                         // Recursive: list all files under $dir and its subdirs
 939                         if ( !empty( $params['adviseStat'] ) ) {
 940                                 $status = $this->objectListing( $fullCont, 'info', $limit, $after, $prefix );
 941                         } else {
 942                                 $status = $this->objectListing( $fullCont, 'names', $limit, $after, $prefix );
 943                         }
 944                 }
 945
 946                 // Reformat this list into a list of (name, stat array or null) entries
 947                 if ( !$status->isOk() ) {
 948                         return $files; // error
 949                 }
 950
 951                 $objects = $status->value;
 952                 $files = $this->buildFileObjectListing( $params, $dir, $objects );
 953
 954                 // Page on the unfiltered object listing (what is returned may be filtered)
 955                 if ( count( $objects ) < $limit ) {
 956                         $after = INF; // avoid a second RTT
 957                 } else {
 958                         $after = end( $objects ); // update last item
 959                         $after = is_object( $after ) ? $after->name : $after;
 960                 }
 961
 962                 return $files;
 963         }
 964
 965         /**
 966          * Build a list of file objects, filtering out any directories
 967          * and extracting any stat info if provided in $objects (for CF_Objects)
 968          *
 969          * @param array $params Parameters for getDirectoryList()
 970          * @param string $dir Resolved container directory path
 971          * @param array $objects List of CF_Object items or object names
 972          * @return array List of (names,stat array or null) entries
 973          */
 974         private function buildFileObjectListing( array $params, $dir, array $objects ) {
 975                 $names = array();
 976                 foreach ( $objects as $object ) {
 977                         if ( is_object( $object ) ) {
 978                                 if ( isset( $object->subdir ) || !isset( $object->name ) ) {
 979                                         continue; // virtual directory entry; ignore
 980                                 }
 981                                 $stat = array(
 982                                         // Convert various random Swift dates to TS_MW
 983                                         'mtime'  => $this->convertSwiftDate( $object->last_modified, TS_MW ),
 984                                         'size'   => (int)$object->bytes,
 985                                         'sha1'   => null,
 986                                         // Note: manifiest ETags are not an MD5 of the file
 987                                         'md5'    => ctype_xdigit( $object->hash ) ? $object->hash : null,
 988                                         'latest' => false // eventually consistent
 989                                 );
 990                                 $names[] = array( $object->name, $stat );
 991                         } elseif ( substr( $object, -1 ) !== '/' ) {
 992                                 // Omit directories, which end in '/' in listings
 993                                 $names[] = array( $object, null );
 994                         }
 995                 }
 996
 997                 return $names;
 998         }
 999
1000         /**
1001          * Do not call this function outside of SwiftFileBackendFileList
1002          *
1003          * @param string $path Storage path
1004          * @param array $val Stat value
1005          */
1006         public function loadListingStatInternal( $path, array $val ) {
1007                 $this->cheapCache->set( $path, 'stat', $val );
1008         }
1009
1010         protected function doGetFileXAttributes( array $params ) {
1011                 $stat = $this->getFileStat( $params );
1012                 if ( $stat ) {
1013                         if ( !isset( $stat['xattr'] ) ) {
1014                                 // Stat entries filled by file listings don't include metadata/headers
1015                                 $this->clearCache( array( $params['src'] ) );
1016                                 $stat = $this->getFileStat( $params );
1017                         }
1018
1019                         return $stat['xattr'];
1020                 } else {
1021                         return false;
1022                 }
1023         }
1024
1025         protected function doGetFileSha1base36( array $params ) {
1026                 $stat = $this->getFileStat( $params );
1027                 if ( $stat ) {
1028                         if ( !isset( $stat['sha1'] ) ) {
1029                                 // Stat entries filled by file listings don't include SHA1
1030                                 $this->clearCache( array( $params['src'] ) );
1031                                 $stat = $this->getFileStat( $params );
1032                         }
1033
1034                         return $stat['sha1'];
1035                 } else {
1036                         return false;
1037                 }
1038         }
1039
1040         protected function doStreamFile( array $params ) {
1041                 $status = Status::newGood();
1042
1043                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
1044                 if ( $srcRel === null ) {
1045                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
1046                 }
1047
1048                 $auth = $this->getAuthentication();
1049                 if ( !$auth || !is_array( $this->getContainerStat( $srcCont ) ) ) {
1050                         $status->fatal( 'backend-fail-stream', $params['src'] );
1051
1052                         return $status;
1053                 }
1054
1055                 $handle = fopen( 'php://output', 'wb' );
1056
1057                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1058                         'method' => 'GET',
1059                         'url' => $this->storageUrl( $auth, $srcCont, $srcRel ),
1060                         'headers' => $this->authTokenHeaders( $auth )
1061                                 + $this->headersFromParams( $params ),
1062                         'stream' => $handle,
1063                 ) );
1064
1065                 if ( $rcode >= 200 && $rcode <= 299 ) {
1066                         // good
1067                 } elseif ( $rcode === 404 ) {
1068                         $status->fatal( 'backend-fail-stream', $params['src'] );
1069                 } else {
1070                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc );
1071                 }
1072
1073                 return $status;
1074         }
1075
1076         protected function doGetLocalCopyMulti( array $params ) {
1077                 $tmpFiles = array();
1078
1079                 $auth = $this->getAuthentication();
1080
1081                 $ep = array_diff_key( $params, array( 'srcs' => 1 ) ); // for error logging
1082                 // Blindly create tmp files and stream to them, catching any exception if the file does
1083                 // not exist. Doing a stat here is useless causes infinite loops in addMissingMetadata().
1084                 $reqs = array(); // (path => op)
1085
1086                 foreach ( $params['srcs'] as $path ) { // each path in this concurrent batch
1087                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
1088                         if ( $srcRel === null || !$auth ) {
1089                                 $tmpFiles[$path] = null;
1090                                 continue;
1091                         }
1092                         // Get source file extension
1093                         $ext = FileBackend::extensionFromPath( $path );
1094                         // Create a new temporary file...
1095                         $tmpFile = TempFSFile::factory( 'localcopy_', $ext );
1096                         if ( $tmpFile ) {
1097                                 $handle = fopen( $tmpFile->getPath(), 'wb' );
1098                                 if ( $handle ) {
1099                                         $reqs[$path] = array(
1100                                                 'method'  => 'GET',
1101                                                 'url'     => $this->storageUrl( $auth, $srcCont, $srcRel ),
1102                                                 'headers' => $this->authTokenHeaders( $auth )
1103                                                         + $this->headersFromParams( $params ),
1104                                                 'stream'  => $handle,
1105                                         );
1106                                 } else {
1107                                         $tmpFile = null;
1108                                 }
1109                         }
1110                         $tmpFiles[$path] = $tmpFile;
1111                 }
1112
1113                 $isLatest = ( $this->isRGW || !empty( $params['latest'] ) );
1114                 $opts = array( 'maxConnsPerHost' => $params['concurrency'] );
1115                 $reqs = $this->http->runMulti( $reqs, $opts );
1116                 foreach ( $reqs as $path => $op ) {
1117                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $op['response'];
1118                         fclose( $op['stream'] ); // close open handle
1119                         if ( $rcode >= 200 && $rcode <= 299 ) {
1120                                 $size = $tmpFiles[$path] ? $tmpFiles[$path]->getSize() : 0;
1121                                 // Double check that the disk is not full/broken
1122                                 if ( $size != $rhdrs['content-length'] ) {
1123                                         $tmpFiles[$path] = null;
1124                                         $rerr = "Got {$size}/{$rhdrs['content-length']} bytes";
1125                                         $this->onError( null, __METHOD__,
1126                                                 array( 'src' => $path ) + $ep, $rerr, $rcode, $rdesc );
1127                                 }
1128                                 // Set the file stat process cache in passing
1129                                 $stat = $this->getStatFromHeaders( $rhdrs );
1130                                 $stat['latest'] = $isLatest;
1131                                 $this->cheapCache->set( $path, 'stat', $stat );
1132                         } elseif ( $rcode === 404 ) {
1133                                 $tmpFiles[$path] = false;
1134                         } else {
1135                                 $tmpFiles[$path] = null;
1136                                 $this->onError( null, __METHOD__,
1137                                         array( 'src' => $path ) + $ep, $rerr, $rcode, $rdesc );
1138                         }
1139                 }
1140
1141                 return $tmpFiles;
1142         }
1143
1144         public function getFileHttpUrl( array $params ) {
1145                 if ( $this->swiftTempUrlKey != '' ||
1146                         ( $this->rgwS3AccessKey != '' && $this->rgwS3SecretKey != '' )
1147                 ) {
1148                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
1149                         if ( $srcRel === null ) {
1150                                 return null; // invalid path
1151                         }
1152
1153                         $auth = $this->getAuthentication();
1154                         if ( !$auth ) {
1155                                 return null;
1156                         }
1157
1158                         $ttl = isset( $params['ttl'] ) ? $params['ttl'] : 86400;
1159                         $expires = time() + $ttl;
1160
1161                         if ( $this->swiftTempUrlKey != '' ) {
1162                                 $url = $this->storageUrl( $auth, $srcCont, $srcRel );
1163                                 // Swift wants the signature based on the unencoded object name
1164                                 $contPath = parse_url( $this->storageUrl( $auth, $srcCont ), PHP_URL_PATH );
1165                                 $signature = hash_hmac( 'sha1',
1166                                         "GET\n{$expires}\n{$contPath}/{$srcRel}",
1167                                         $this->swiftTempUrlKey
1168                                 );
1169
1170                                 return "{$url}?temp_url_sig={$signature}&temp_url_expires={$expires}";
1171                         } else { // give S3 API URL for rgw
1172                                 // Path for signature starts with the bucket
1173                                 $spath = '/' . rawurlencode( $srcCont ) . '/' .
1174                                         str_replace( '%2F', '/', rawurlencode( $srcRel ) );
1175                                 // Calculate the hash
1176                                 $signature = base64_encode( hash_hmac(
1177                                         'sha1',
1178                                         "GET\n\n\n{$expires}\n{$spath}",
1179                                         $this->rgwS3SecretKey,
1180                                         true // raw
1181                                 ) );
1182                                 // See http://s3.amazonaws.com/doc/s3-developer-guide/RESTAuthentication.html.
1183                                 // Note: adding a newline for empty CanonicalizedAmzHeaders does not work.
1184                                 return wfAppendQuery(
1185                                         str_replace( '/swift/v1', '', // S3 API is the rgw default
1186                                                 $this->storageUrl( $auth ) . $spath ),
1187                                         array(
1188                                                 'Signature' => $signature,
1189                                                 'Expires' => $expires,
1190                                                 'AWSAccessKeyId' => $this->rgwS3AccessKey )
1191                                 );
1192                         }
1193                 }
1194
1195                 return null;
1196         }
1197
1198         protected function directoriesAreVirtual() {
1199                 return true;
1200         }
1201
1202         /**
1203          * Get headers to send to Swift when reading a file based
1204          * on a FileBackend params array, e.g. that of getLocalCopy().
1205          * $params is currently only checked for a 'latest' flag.
1206          *
1207          * @param array $params
1208          * @return array
1209          */
1210         protected function headersFromParams( array $params ) {
1211                 $hdrs = array();
1212                 if ( !empty( $params['latest'] ) ) {
1213                         $hdrs['x-newest'] = 'true';
1214                 }
1215
1216                 return $hdrs;
1217         }
1218
1219         /**
1220          * @param FileBackendStoreOpHandle[] $fileOpHandles
1221          *
1222          * @return Status[]
1223          */
1224         protected function doExecuteOpHandlesInternal( array $fileOpHandles ) {
1225                 $statuses = array();
1226
1227                 $auth = $this->getAuthentication();
1228                 if ( !$auth ) {
1229                         foreach ( $fileOpHandles as $index => $fileOpHandle ) {
1230                                 $statuses[$index] = Status::newFatal( 'backend-fail-connect', $this->name );
1231                         }
1232
1233                         return $statuses;
1234                 }
1235
1236                 // Split the HTTP requests into stages that can be done concurrently
1237                 $httpReqsByStage = array(); // map of (stage => index => HTTP request)
1238                 foreach ( $fileOpHandles as $index => $fileOpHandle ) {
1239                         $reqs = $fileOpHandle->httpOp;
1240                         // Convert the 'url' parameter to an actual URL using $auth
1241                         foreach ( $reqs as $stage => &$req ) {
1242                                 list( $container, $relPath ) = $req['url'];
1243                                 $req['url'] = $this->storageUrl( $auth, $container, $relPath );
1244                                 $req['headers'] = isset( $req['headers'] ) ? $req['headers'] : array();
1245                                 $req['headers'] = $this->authTokenHeaders( $auth ) + $req['headers'];
1246                                 $httpReqsByStage[$stage][$index] = $req;
1247                         }
1248                         $statuses[$index] = Status::newGood();
1249                 }
1250
1251                 // Run all requests for the first stage, then the next, and so on
1252                 $reqCount = count( $httpReqsByStage );
1253                 for ( $stage = 0; $stage < $reqCount; ++$stage ) {
1254                         $httpReqs = $this->http->runMulti( $httpReqsByStage[$stage] );
1255                         foreach ( $httpReqs as $index => $httpReq ) {
1256                                 // Run the callback for each request of this operation
1257                                 $callback = $fileOpHandles[$index]->callback;
1258                                 call_user_func_array( $callback, array( $httpReq, $statuses[$index] ) );
1259                                 // On failure, abort all remaining requests for this operation
1260                                 // (e.g. abort the DELETE request if the COPY request fails for a move)
1261                                 if ( !$statuses[$index]->isOK() ) {
1262                                         $stages = count( $fileOpHandles[$index]->httpOp );
1263                                         for ( $s = ( $stage + 1 ); $s < $stages; ++$s ) {
1264                                                 unset( $httpReqsByStage[$s][$index] );
1265                                         }
1266                                 }
1267                         }
1268                 }
1269
1270                 return $statuses;
1271         }
1272
1273         /**
1274          * Set read/write permissions for a Swift container.
1275          *
1276          * @see http://swift.openstack.org/misc.html#acls
1277          *
1278          * In general, we don't allow listings to end-users. It's not useful, isn't well-defined
1279          * (lists are truncated to 10000 item with no way to page), and is just a performance risk.
1280          *
1281          * @param string $container Resolved Swift container
1282          * @param array $readGrps List of the possible criteria for a request to have
1283          * access to read a container. Each item is one of the following formats:
1284          *   - account:user        : Grants access if the request is by the given user
1285          *   - ".r:<regex>"        : Grants access if the request is from a referrer host that
1286          *                           matches the expression and the request is not for a listing.
1287          *                           Setting this to '*' effectively makes a container public.
1288          *   -".rlistings:<regex>" : Grants access if the request is from a referrer host that
1289          *                           matches the expression and the request is for a listing.
1290          * @param array $writeGrps A list of the possible criteria for a request to have
1291          * access to write to a container. Each item is of the following format:
1292          *   - account:user       : Grants access if the request is by the given user
1293          * @return Status
1294          */
1295         protected function setContainerAccess( $container, array $readGrps, array $writeGrps ) {
1296                 $status = Status::newGood();
1297                 $auth = $this->getAuthentication();
1298
1299                 if ( !$auth ) {
1300                         $status->fatal( 'backend-fail-connect', $this->name );
1301
1302                         return $status;
1303                 }
1304
1305                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1306                         'method' => 'POST',
1307                         'url' => $this->storageUrl( $auth, $container ),
1308                         'headers' => $this->authTokenHeaders( $auth ) + array(
1309                                 'x-container-read' => implode( ',', $readGrps ),
1310                                 'x-container-write' => implode( ',', $writeGrps )
1311                         )
1312                 ) );
1313
1314                 if ( $rcode != 204 && $rcode !== 202 ) {
1315                         $status->fatal( 'backend-fail-internal', $this->name );
1316                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': unexpected rcode value (' . $rcode . ')' );
1317                 }
1318
1319                 return $status;
1320         }
1321
1322         /**
1323          * Get a Swift container stat array, possibly from process cache.
1324          * Use $reCache if the file count or byte count is needed.
1325          *
1326          * @param string $container Container name
1327          * @param bool $bypassCache Bypass all caches and load from Swift
1328          * @return array|bool|null False on 404, null on failure
1329          */
1330         protected function getContainerStat( $container, $bypassCache = false ) {
1331                 $ps = Profiler::instance()->scopedProfileIn( __METHOD__ . "-{$this->name}" );
1332
1333                 if ( $bypassCache ) { // purge cache
1334                         $this->containerStatCache->clear( $container );
1335                 } elseif ( !$this->containerStatCache->has( $container, 'stat' ) ) {
1336                         $this->primeContainerCache( array( $container ) ); // check persistent cache
1337                 }
1338                 if ( !$this->containerStatCache->has( $container, 'stat' ) ) {
1339                         $auth = $this->getAuthentication();
1340                         if ( !$auth ) {
1341                                 return null;
1342                         }
1343
1344                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1345                                 'method' => 'HEAD',
1346                                 'url' => $this->storageUrl( $auth, $container ),
1347                                 'headers' => $this->authTokenHeaders( $auth )
1348                         ) );
1349
1350                         if ( $rcode === 204 ) {
1351                                 $stat = array(
1352                                         'count' => $rhdrs['x-container-object-count'],
1353                                         'bytes' => $rhdrs['x-container-bytes-used']
1354                                 );
1355                                 if ( $bypassCache ) {
1356                                         return $stat;
1357                                 } else {
1358                                         $this->containerStatCache->set( $container, 'stat', $stat ); // cache it
1359                                         $this->setContainerCache( $container, $stat ); // update persistent cache
1360                                 }
1361                         } elseif ( $rcode === 404 ) {
1362                                 return false;
1363                         } else {
1364                                 $this->onError( null, __METHOD__,
1365                                         array( 'cont' => $container ), $rerr, $rcode, $rdesc );
1366
1367                                 return null;
1368                         }
1369                 }
1370
1371                 return $this->containerStatCache->get( $container, 'stat' );
1372         }
1373
1374         /**
1375          * Create a Swift container
1376          *
1377          * @param string $container Container name
1378          * @param array $params
1379          * @return Status
1380          */
1381         protected function createContainer( $container, array $params ) {
1382                 $status = Status::newGood();
1383
1384                 $auth = $this->getAuthentication();
1385                 if ( !$auth ) {
1386                         $status->fatal( 'backend-fail-connect', $this->name );
1387
1388                         return $status;
1389                 }
1390
1391                 // @see SwiftFileBackend::setContainerAccess()
1392                 if ( empty( $params['noAccess'] ) ) {
1393                         $readGrps = array( '.r:*', $this->swiftUser ); // public
1394                 } else {
1395                         $readGrps = array( $this->swiftUser ); // private
1396                 }
1397                 $writeGrps = array( $this->swiftUser ); // sanity
1398
1399                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1400                         'method' => 'PUT',
1401                         'url' => $this->storageUrl( $auth, $container ),
1402                         'headers' => $this->authTokenHeaders( $auth ) + array(
1403                                 'x-container-read' => implode( ',', $readGrps ),
1404                                 'x-container-write' => implode( ',', $writeGrps )
1405                         )
1406                 ) );
1407
1408                 if ( $rcode === 201 ) { // new
1409                         // good
1410                 } elseif ( $rcode === 202 ) { // already there
1411                         // this shouldn't really happen, but is OK
1412                 } else {
1413                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc );
1414                 }
1415
1416                 return $status;
1417         }
1418
1419         /**
1420          * Delete a Swift container
1421          *
1422          * @param string $container Container name
1423          * @param array $params
1424          * @return Status
1425          */
1426         protected function deleteContainer( $container, array $params ) {
1427                 $status = Status::newGood();
1428
1429                 $auth = $this->getAuthentication();
1430                 if ( !$auth ) {
1431                         $status->fatal( 'backend-fail-connect', $this->name );
1432
1433                         return $status;
1434                 }
1435
1436                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1437                         'method' => 'DELETE',
1438                         'url' => $this->storageUrl( $auth, $container ),
1439                         'headers' => $this->authTokenHeaders( $auth )
1440                 ) );
1441
1442                 if ( $rcode >= 200 && $rcode <= 299 ) { // deleted
1443                         $this->containerStatCache->clear( $container ); // purge
1444                 } elseif ( $rcode === 404 ) { // not there
1445                         // this shouldn't really happen, but is OK
1446                 } elseif ( $rcode === 409 ) { // not empty
1447                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc ); // race?
1448                 } else {
1449                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc );
1450                 }
1451
1452                 return $status;
1453         }
1454
1455         /**
1456          * Get a list of objects under a container.
1457          * Either just the names or a list of stdClass objects with details can be returned.
1458          *
1459          * @param string $fullCont
1460          * @param string $type ('info' for a list of object detail maps, 'names' for names only)
1461          * @param int $limit
1462          * @param string|null $after
1463          * @param string|null $prefix
1464          * @param string|null $delim
1465          * @return Status With the list as value
1466          */
1467         private function objectListing(
1468                 $fullCont, $type, $limit, $after = null, $prefix = null, $delim = null
1469         ) {
1470                 $status = Status::newGood();
1471
1472                 $auth = $this->getAuthentication();
1473                 if ( !$auth ) {
1474                         $status->fatal( 'backend-fail-connect', $this->name );
1475
1476                         return $status;
1477                 }
1478
1479                 $query = array( 'limit' => $limit );
1480                 if ( $type === 'info' ) {
1481                         $query['format'] = 'json';
1482                 }
1483                 if ( $after !== null ) {
1484                         $query['marker'] = $after;
1485                 }
1486                 if ( $prefix !== null ) {
1487                         $query['prefix'] = $prefix;
1488                 }
1489                 if ( $delim !== null ) {
1490                         $query['delimiter'] = $delim;
1491                 }
1492
1493                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1494                         'method' => 'GET',
1495                         'url' => $this->storageUrl( $auth, $fullCont ),
1496                         'query' => $query,
1497                         'headers' => $this->authTokenHeaders( $auth )
1498                 ) );
1499
1500                 $params = array( 'cont' => $fullCont, 'prefix' => $prefix, 'delim' => $delim );
1501                 if ( $rcode === 200 ) { // good
1502                         if ( $type === 'info' ) {
1503                                 $status->value = FormatJson::decode( trim( $rbody ) );
1504                         } else {
1505                                 $status->value = explode( "\n", trim( $rbody ) );
1506                         }
1507                 } elseif ( $rcode === 204 ) {
1508                         $status->value = array(); // empty container
1509                 } elseif ( $rcode === 404 ) {
1510                         $status->value = array(); // no container
1511                 } else {
1512                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc );
1513                 }
1514
1515                 return $status;
1516         }
1517
1518         protected function doPrimeContainerCache( array $containerInfo ) {
1519                 foreach ( $containerInfo as $container => $info ) {
1520                         $this->containerStatCache->set( $container, 'stat', $info );
1521                 }
1522         }
1523
1524         protected function doGetFileStatMulti( array $params ) {
1525                 $stats = array();
1526
1527                 $auth = $this->getAuthentication();
1528
1529                 $reqs = array();
1530                 foreach ( $params['srcs'] as $path ) {
1531                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
1532                         if ( $srcRel === null ) {
1533                                 $stats[$path] = false;
1534                                 continue; // invalid storage path
1535                         } elseif ( !$auth ) {
1536                                 $stats[$path] = null;
1537                                 continue;
1538                         }
1539
1540                         // (a) Check the container
1541                         $cstat = $this->getContainerStat( $srcCont );
1542                         if ( $cstat === false ) {
1543                                 $stats[$path] = false;
1544                                 continue; // ok, nothing to do
1545                         } elseif ( !is_array( $cstat ) ) {
1546                                 $stats[$path] = null;
1547                                 continue;
1548                         }
1549
1550                         $reqs[$path] = array(
1551                                 'method'  => 'HEAD',
1552                                 'url'     => $this->storageUrl( $auth, $srcCont, $srcRel ),
1553                                 'headers' => $this->authTokenHeaders( $auth ) + $this->headersFromParams( $params )
1554                         );
1555                 }
1556
1557                 $opts = array( 'maxConnsPerHost' => $params['concurrency'] );
1558                 $reqs = $this->http->runMulti( $reqs, $opts );
1559
1560                 foreach ( $params['srcs'] as $path ) {
1561                         if ( array_key_exists( $path, $stats ) ) {
1562                                 continue; // some sort of failure above
1563                         }
1564                         // (b) Check the file
1565                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $reqs[$path]['response'];
1566                         if ( $rcode === 200 || $rcode === 204 ) {
1567                                 // Update the object if it is missing some headers
1568                                 $rhdrs = $this->addMissingMetadata( $rhdrs, $path );
1569                                 // Load the stat array from the headers
1570                                 $stat = $this->getStatFromHeaders( $rhdrs );
1571                                 if ( $this->isRGW ) {
1572                                         $stat['latest'] = true; // strong consistency
1573                                 }
1574                         } elseif ( $rcode === 404 ) {
1575                                 $stat = false;
1576                         } else {
1577                                 $stat = null;
1578                                 $this->onError( null, __METHOD__, $params, $rerr, $rcode, $rdesc );
1579                         }
1580                         $stats[$path] = $stat;
1581                 }
1582
1583                 return $stats;
1584         }
1585
1586         /**
1587          * @param array $rhdrs
1588          * @return array
1589          */
1590         protected function getStatFromHeaders( array $rhdrs ) {
1591                 // Fetch all of the custom metadata headers
1592                 $metadata = $this->getMetadata( $rhdrs );
1593                 // Fetch all of the custom raw HTTP headers
1594                 $headers = $this->sanitizeHdrs( array( 'headers' => $rhdrs ) );
1595
1596                 return array(
1597                         // Convert various random Swift dates to TS_MW
1598                         'mtime' => $this->convertSwiftDate( $rhdrs['last-modified'], TS_MW ),
1599                         // Empty objects actually return no content-length header in Ceph
1600                         'size'  => isset( $rhdrs['content-length'] ) ? (int)$rhdrs['content-length'] : 0,
1601                         'sha1'  => isset( $metadata['sha1base36'] ) ? $metadata['sha1base36'] : null,
1602                         // Note: manifiest ETags are not an MD5 of the file
1603                         'md5'   => ctype_xdigit( $rhdrs['etag'] ) ? $rhdrs['etag'] : null,
1604                         'xattr' => array( 'metadata' => $metadata, 'headers' => $headers )
1605                 );
1606         }
1607
1608         /**
1609          * @return array|null Credential map
1610          */
1611         protected function getAuthentication() {
1612                 if ( $this->authErrorTimestamp !== null ) {
1613                         if ( ( time() - $this->authErrorTimestamp ) < 60 ) {
1614                                 return null; // failed last attempt; don't bother
1615                         } else { // actually retry this time
1616                                 $this->authErrorTimestamp = null;
1617                         }
1618                 }
1619                 // Session keys expire after a while, so we renew them periodically
1620                 $reAuth = ( ( time() - $this->authSessionTimestamp ) > $this->authTTL );
1621                 // Authenticate with proxy and get a session key...
1622                 if ( !$this->authCreds || $reAuth ) {
1623                         $this->authSessionTimestamp = 0;
1624                         $cacheKey = $this->getCredsCacheKey( $this->swiftUser );
1625                         $creds = $this->srvCache->get( $cacheKey ); // credentials
1626                         // Try to use the credential cache
1627                         if ( isset( $creds['auth_token'] ) && isset( $creds['storage_url'] ) ) {
1628                                 $this->authCreds = $creds;
1629                                 // Skew the timestamp for worst case to avoid using stale credentials
1630                                 $this->authSessionTimestamp = time() - ceil( $this->authTTL / 2 );
1631                         } else { // cache miss
1632                                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1633                                         'method' => 'GET',
1634                                         'url' => "{$this->swiftAuthUrl}/v1.0",
1635                                         'headers' => array(
1636                                                 'x-auth-user' => $this->swiftUser,
1637                                                 'x-auth-key' => $this->swiftKey
1638                                         )
1639                                 ) );
1640
1641                                 if ( $rcode >= 200 && $rcode <= 299 ) { // OK
1642                                         $this->authCreds = array(
1643                                                 'auth_token' => $rhdrs['x-auth-token'],
1644                                                 'storage_url' => $rhdrs['x-storage-url']
1645                                         );
1646                                         $this->srvCache->set( $cacheKey, $this->authCreds, ceil( $this->authTTL / 2 ) );
1647                                         $this->authSessionTimestamp = time();
1648                                 } elseif ( $rcode === 401 ) {
1649                                         $this->onError( null, __METHOD__, array(), "Authentication failed.", $rcode );
1650                                         $this->authErrorTimestamp = time();
1651
1652                                         return null;
1653                                 } else {
1654                                         $this->onError( null, __METHOD__, array(), "HTTP return code: $rcode", $rcode );
1655                                         $this->authErrorTimestamp = time();
1656
1657                                         return null;
1658                                 }
1659                         }
1660                         // Ceph RGW does not use <account> in URLs (OpenStack Swift uses "/v1/<account>")
1661                         if ( substr( $this->authCreds['storage_url'], -3 ) === '/v1' ) {
1662                                 $this->isRGW = true; // take advantage of strong consistency in Ceph
1663                         }
1664                 }
1665
1666                 return $this->authCreds;
1667         }
1668
1669         /**
1670          * @param array $creds From getAuthentication()
1671          * @param string $container
1672          * @param string $object
1673          * @return array
1674          */
1675         protected function storageUrl( array $creds, $container = null, $object = null ) {
1676                 $parts = array( $creds['storage_url'] );
1677                 if ( strlen( $container ) ) {
1678                         $parts[] = rawurlencode( $container );
1679                 }
1680                 if ( strlen( $object ) ) {
1681                         $parts[] = str_replace( "%2F", "/", rawurlencode( $object ) );
1682                 }
1683
1684                 return implode( '/', $parts );
1685         }
1686
1687         /**
1688          * @param array $creds From getAuthentication()
1689          * @return array
1690          */
1691         protected function authTokenHeaders( array $creds ) {
1692                 return array( 'x-auth-token' => $creds['auth_token'] );
1693         }
1694
1695         /**
1696          * Get the cache key for a container
1697          *
1698          * @param string $username
1699          * @return string
1700          */
1701         private function getCredsCacheKey( $username ) {
1702                 return 'swiftcredentials:' . md5( $username . ':' . $this->swiftAuthUrl );
1703         }
1704
1705         /**
1706          * Log an unexpected exception for this backend.
1707          * This also sets the Status object to have a fatal error.
1708          *
1709          * @param Status|null $status
1710          * @param string $func
1711          * @param array $params
1712          * @param string $err Error string
1713          * @param int $code HTTP status
1714          * @param string $desc HTTP status description
1715          */
1716         public function onError( $status, $func, array $params, $err = '', $code = 0, $desc = '' ) {
1717                 if ( $status instanceof Status ) {
1718                         $status->fatal( 'backend-fail-internal', $this->name );
1719                 }
1720                 if ( $code == 401 ) { // possibly a stale token
1721                         $this->srvCache->delete( $this->getCredsCacheKey( $this->swiftUser ) );
1722                 }
1723                 wfDebugLog( 'SwiftBackend',
1724                         "HTTP $code ($desc) in '{$func}' (given '" . FormatJson::encode( $params ) . "')" .
1725                         ( $err ? ": $err" : "" )
1726                 );
1727         }
1728 }
1729
1730 /**
1731  * @see FileBackendStoreOpHandle
1732  */
1733 class SwiftFileOpHandle extends FileBackendStoreOpHandle {
1734         /** @var array List of Requests for MultiHttpClient */
1735         public $httpOp;
1736         /** @var Closure */
1737         public $callback;
1738
1739         /**
1740          * @param SwiftFileBackend $backend
1741          * @param Closure $callback Function that takes (HTTP request array, status)
1742          * @param array $httpOp MultiHttpClient op
1743          */
1744         public function __construct( SwiftFileBackend $backend, Closure $callback, array $httpOp ) {
1745                 $this->backend = $backend;
1746                 $this->callback = $callback;
1747                 $this->httpOp = $httpOp;
1748         }
1749 }
1750
1751 /**
1752  * SwiftFileBackend helper class to page through listings.
1753  * Swift also has a listing limit of 10,000 objects for sanity.
1754  * Do not use this class from places outside SwiftFileBackend.
1755  *
1756  * @ingroup FileBackend
1757  */
1758 abstract class SwiftFileBackendList implements Iterator {
1759         /** @var array List of path or (path,stat array) entries */
1760         protected $bufferIter = array();
1761
1762         /** @var string List items *after* this path */
1763         protected $bufferAfter = null;
1764
1765         /** @var int */
1766         protected $pos = 0;
1767
1768         /** @var array */
1769         protected $params = array();
1770
1771         /** @var SwiftFileBackend */
1772         protected $backend;
1773
1774         /** @var string Container name */
1775         protected $container;
1776
1777         /** @var string Storage directory */
1778         protected $dir;
1779
1780         /** @var int */
1781         protected $suffixStart;
1782
1783         const PAGE_SIZE = 9000; // file listing buffer size
1784
1785         /**
1786          * @param SwiftFileBackend $backend
1787          * @param string $fullCont Resolved container name
1788          * @param string $dir Resolved directory relative to container
1789          * @param array $params
1790          */
1791         public function __construct( SwiftFileBackend $backend, $fullCont, $dir, array $params ) {
1792                 $this->backend = $backend;
1793                 $this->container = $fullCont;
1794                 $this->dir = $dir;
1795                 if ( substr( $this->dir, -1 ) === '/' ) {
1796                         $this->dir = substr( $this->dir, 0, -1 ); // remove trailing slash
1797                 }
1798                 if ( $this->dir == '' ) { // whole container
1799                         $this->suffixStart = 0;
1800                 } else { // dir within container
1801                         $this->suffixStart = strlen( $this->dir ) + 1; // size of "path/to/dir/"
1802                 }
1803                 $this->params = $params;
1804         }
1805
1806         /**
1807          * @see Iterator::key()
1808          * @return int
1809          */
1810         public function key() {
1811                 return $this->pos;
1812         }
1813
1814         /**
1815          * @see Iterator::next()
1816          */
1817         public function next() {
1818                 // Advance to the next file in the page
1819                 next( $this->bufferIter );
1820                 ++$this->pos;
1821                 // Check if there are no files left in this page and
1822                 // advance to the next page if this page was not empty.
1823                 if ( !$this->valid() && count( $this->bufferIter ) ) {
1824                         $this->bufferIter = $this->pageFromList(
1825                                 $this->container, $this->dir, $this->bufferAfter, self::PAGE_SIZE, $this->params
1826                         ); // updates $this->bufferAfter
1827                 }
1828         }
1829
1830         /**
1831          * @see Iterator::rewind()
1832          */
1833         public function rewind() {
1834                 $this->pos = 0;
1835                 $this->bufferAfter = null;
1836                 $this->bufferIter = $this->pageFromList(
1837                         $this->container, $this->dir, $this->bufferAfter, self::PAGE_SIZE, $this->params
1838                 ); // updates $this->bufferAfter
1839         }
1840
1841         /**
1842          * @see Iterator::valid()
1843          * @return bool
1844          */
1845         public function valid() {
1846                 if ( $this->bufferIter === null ) {
1847                         return false; // some failure?
1848                 } else {
1849                         return ( current( $this->bufferIter ) !== false ); // no paths can have this value
1850                 }
1851         }
1852
1853         /**
1854          * Get the given list portion (page)
1855          *
1856          * @param string $container Resolved container name
1857          * @param string $dir Resolved path relative to container
1858          * @param string $after
1859          * @param int $limit
1860          * @param array $params
1861          * @return Traversable|array
1862          */
1863         abstract protected function pageFromList( $container, $dir, &$after, $limit, array $params );
1864 }
1865
1866 /**
1867  * Iterator for listing directories
1868  */
1869 class SwiftFileBackendDirList extends SwiftFileBackendList {
1870         /**
1871          * @see Iterator::current()
1872          * @return string|bool String (relative path) or false
1873          */
1874         public function current() {
1875                 return substr( current( $this->bufferIter ), $this->suffixStart, -1 );
1876         }
1877
1878         protected function pageFromList( $container, $dir, &$after, $limit, array $params ) {
1879                 return $this->backend->getDirListPageInternal( $container, $dir, $after, $limit, $params );
1880         }
1881 }
1882
1883 /**
1884  * Iterator for listing regular files
1885  */
1886 class SwiftFileBackendFileList extends SwiftFileBackendList {
1887         /**
1888          * @see Iterator::current()
1889          * @return string|bool String (relative path) or false
1890          */
1891         public function current() {
1892                 list( $path, $stat ) = current( $this->bufferIter );
1893                 $relPath = substr( $path, $this->suffixStart );
1894                 if ( is_array( $stat ) ) {
1895                         $storageDir = rtrim( $this->params['dir'], '/' );
1896                         $this->backend->loadListingStatInternal( "$storageDir/$relPath", $stat );
1897                 }
1898
1899                 return $relPath;
1900         }
1901
1902         protected function pageFromList( $container, $dir, &$after, $limit, array $params ) {
1903                 return $this->backend->getFileListPageInternal( $container, $dir, $after, $limit, $params );
1904         }
1905 }