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