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                                 // look for APC, XCache, WinCache, ect...
 142                                 $this->srvCache = ObjectCache::newAccelerator( CACHE_NONE );
 143                         }
 144                 } else {
 145                         $this->srvCache = new EmptyBagOStuff();
 146                 }
 147         }
 148
 149         public function getFeatures() {
 150                 return ( FileBackend::ATTR_UNICODE_PATHS |
 151                         FileBackend::ATTR_HEADERS | FileBackend::ATTR_METADATA );
 152         }
 153
 154         protected function resolveContainerPath( $container, $relStoragePath ) {
 155                 if ( !mb_check_encoding( $relStoragePath, 'UTF-8' ) ) { // mb_string required by CF
 156                         return null; // not UTF-8, makes it hard to use CF and the swift HTTP API
 157                 } elseif ( strlen( urlencode( $relStoragePath ) ) > 1024 ) {
 158                         return null; // too long for Swift
 159                 }
 160
 161                 return $relStoragePath;
 162         }
 163
 164         public function isPathUsableInternal( $storagePath ) {
 165                 list( $container, $rel ) = $this->resolveStoragePathReal( $storagePath );
 166                 if ( $rel === null ) {
 167                         return false; // invalid
 168                 }
 169
 170                 return is_array( $this->getContainerStat( $container ) );
 171         }
 172
 173         /**
 174          * Sanitize and filter the custom headers from a $params array.
 175          * Only allows certain "standard" Content- and X-Content- headers.
 176          *
 177          * @param array $params
 178          * @return array Sanitized value of 'headers' field in $params
 179          */
 180         protected function sanitizeHdrs( array $params ) {
 181                 return isset( $params['headers'] )
 182                         ? $this->getCustomHeaders( $params['headers'] )
 183                         : array();
 184
 185         }
 186
 187         /**
 188          * @param array $rawHeaders
 189          * @return array Custom non-metadata HTTP headers
 190          */
 191         protected function getCustomHeaders( array $rawHeaders ) {
 192                 $headers = array();
 193
 194                 // Normalize casing, and strip out illegal headers
 195                 foreach ( $rawHeaders as $name => $value ) {
 196                         $name = strtolower( $name );
 197                         if ( preg_match( '/^content-(type|length)$/', $name ) ) {
 198                                 continue; // blacklisted
 199                         } elseif ( preg_match( '/^(x-)?content-/', $name ) ) {
 200                                 $headers[$name] = $value; // allowed
 201                         } elseif ( preg_match( '/^content-(disposition)/', $name ) ) {
 202                                 $headers[$name] = $value; // allowed
 203                         }
 204                 }
 205                 // By default, Swift has annoyingly low maximum header value limits
 206                 if ( isset( $headers['content-disposition'] ) ) {
 207                         $disposition = '';
 208                         // @note: assume FileBackend::makeContentDisposition() already used
 209                         foreach ( explode( ';', $headers['content-disposition'] ) as $part ) {
 210                                 $part = trim( $part );
 211                                 $new = ( $disposition === '' ) ? $part : "{$disposition};{$part}";
 212                                 if ( strlen( $new ) <= 255 ) {
 213                                         $disposition = $new;
 214                                 } else {
 215                                         break; // too long; sigh
 216                                 }
 217                         }
 218                         $headers['content-disposition'] = $disposition;
 219                 }
 220
 221                 return $headers;
 222         }
 223
 224         /**
 225          * @param array $rawHeaders
 226          * @return array Custom metadata headers
 227          */
 228         protected function getMetadataHeaders( array $rawHeaders ) {
 229                 $headers = array();
 230                 foreach ( $rawHeaders as $name => $value ) {
 231                         $name = strtolower( $name );
 232                         if ( strpos( $name, 'x-object-meta-' ) === 0 ) {
 233                                 $headers[$name] = $value;
 234                         }
 235                 }
 236
 237                 return $headers;
 238         }
 239
 240         /**
 241          * @param array $rawHeaders
 242          * @return array Custom metadata headers with prefix removed
 243          */
 244         protected function getMetadata( array $rawHeaders ) {
 245                 $metadata = array();
 246                 foreach ( $this->getMetadataHeaders( $rawHeaders ) as $name => $value ) {
 247                         $metadata[substr( $name, strlen( 'x-object-meta-' ) )] = $value;
 248                 }
 249
 250                 return $metadata;
 251         }
 252
 253         protected function doCreateInternal( array $params ) {
 254                 $status = Status::newGood();
 255
 256                 list( $dstCont, $dstRel ) = $this->resolveStoragePathReal( $params['dst'] );
 257                 if ( $dstRel === null ) {
 258                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 259
 260                         return $status;
 261                 }
 262
 263                 $sha1Hash = wfBaseConvert( sha1( $params['content'] ), 16, 36, 31 );
 264                 $contentType = $this->getContentType( $params['dst'], $params['content'], null );
 265
 266                 $reqs = array( array(
 267                         'method' => 'PUT',
 268                         'url' => array( $dstCont, $dstRel ),
 269                         'headers' => array(
 270                                 'content-length' => strlen( $params['content'] ),
 271                                 'etag' => md5( $params['content'] ),
 272                                 'content-type' => $contentType,
 273                                 'x-object-meta-sha1base36' => $sha1Hash
 274                         ) + $this->sanitizeHdrs( $params ),
 275                         'body' => $params['content']
 276                 ) );
 277
 278                 $that = $this;
 279                 $method = __METHOD__;
 280                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 281                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 282                         if ( $rcode === 201 ) {
 283                                 // good
 284                         } elseif ( $rcode === 412 ) {
 285                                 $status->fatal( 'backend-fail-contenttype', $params['dst'] );
 286                         } else {
 287                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 288                         }
 289                 };
 290
 291                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 292                 if ( !empty( $params['async'] ) ) { // deferred
 293                         $status->value = $opHandle;
 294                 } else { // actually write the object in Swift
 295                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 296                 }
 297
 298                 return $status;
 299         }
 300
 301         protected function doStoreInternal( array $params ) {
 302                 $status = Status::newGood();
 303
 304                 list( $dstCont, $dstRel ) = $this->resolveStoragePathReal( $params['dst'] );
 305                 if ( $dstRel === null ) {
 306                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 307
 308                         return $status;
 309                 }
 310
 311                 MediaWiki\suppressWarnings();
 312                 $sha1Hash = sha1_file( $params['src'] );
 313                 MediaWiki\restoreWarnings();
 314                 if ( $sha1Hash === false ) { // source doesn't exist?
 315                         $status->fatal( 'backend-fail-store', $params['src'], $params['dst'] );
 316
 317                         return $status;
 318                 }
 319                 $sha1Hash = wfBaseConvert( $sha1Hash, 16, 36, 31 );
 320                 $contentType = $this->getContentType( $params['dst'], null, $params['src'] );
 321
 322                 $handle = fopen( $params['src'], 'rb' );
 323                 if ( $handle === false ) { // source doesn't exist?
 324                         $status->fatal( 'backend-fail-store', $params['src'], $params['dst'] );
 325
 326                         return $status;
 327                 }
 328
 329                 $reqs = array( array(
 330                         'method' => 'PUT',
 331                         'url' => array( $dstCont, $dstRel ),
 332                         'headers' => array(
 333                                 'content-length' => filesize( $params['src'] ),
 334                                 'etag' => md5_file( $params['src'] ),
 335                                 'content-type' => $contentType,
 336                                 'x-object-meta-sha1base36' => $sha1Hash
 337                         ) + $this->sanitizeHdrs( $params ),
 338                         'body' => $handle // resource
 339                 ) );
 340
 341                 $that = $this;
 342                 $method = __METHOD__;
 343                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 344                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 345                         if ( $rcode === 201 ) {
 346                                 // good
 347                         } elseif ( $rcode === 412 ) {
 348                                 $status->fatal( 'backend-fail-contenttype', $params['dst'] );
 349                         } else {
 350                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 351                         }
 352                 };
 353
 354                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 355                 if ( !empty( $params['async'] ) ) { // deferred
 356                         $status->value = $opHandle;
 357                 } else { // actually write the object in Swift
 358                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 359                 }
 360
 361                 return $status;
 362         }
 363
 364         protected function doCopyInternal( array $params ) {
 365                 $status = Status::newGood();
 366
 367                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
 368                 if ( $srcRel === null ) {
 369                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 370
 371                         return $status;
 372                 }
 373
 374                 list( $dstCont, $dstRel ) = $this->resolveStoragePathReal( $params['dst'] );
 375                 if ( $dstRel === null ) {
 376                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 377
 378                         return $status;
 379                 }
 380
 381                 $reqs = array( array(
 382                         'method' => 'PUT',
 383                         'url' => array( $dstCont, $dstRel ),
 384                         'headers' => array(
 385                                 'x-copy-from' => '/' . rawurlencode( $srcCont ) .
 386                                         '/' . str_replace( "%2F", "/", rawurlencode( $srcRel ) )
 387                         ) + $this->sanitizeHdrs( $params ), // extra headers merged into object
 388                 ) );
 389
 390                 $that = $this;
 391                 $method = __METHOD__;
 392                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 393                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 394                         if ( $rcode === 201 ) {
 395                                 // good
 396                         } elseif ( $rcode === 404 ) {
 397                                 $status->fatal( 'backend-fail-copy', $params['src'], $params['dst'] );
 398                         } else {
 399                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 400                         }
 401                 };
 402
 403                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 404                 if ( !empty( $params['async'] ) ) { // deferred
 405                         $status->value = $opHandle;
 406                 } else { // actually write the object in Swift
 407                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 408                 }
 409
 410                 return $status;
 411         }
 412
 413         protected function doMoveInternal( array $params ) {
 414                 $status = Status::newGood();
 415
 416                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
 417                 if ( $srcRel === null ) {
 418                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 419
 420                         return $status;
 421                 }
 422
 423                 list( $dstCont, $dstRel ) = $this->resolveStoragePathReal( $params['dst'] );
 424                 if ( $dstRel === null ) {
 425                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 426
 427                         return $status;
 428                 }
 429
 430                 $reqs = array(
 431                         array(
 432                                 'method' => 'PUT',
 433                                 'url' => array( $dstCont, $dstRel ),
 434                                 'headers' => array(
 435                                         'x-copy-from' => '/' . rawurlencode( $srcCont ) .
 436                                                 '/' . str_replace( "%2F", "/", rawurlencode( $srcRel ) )
 437                                 ) + $this->sanitizeHdrs( $params ) // extra headers merged into object
 438                         )
 439                 );
 440                 if ( "{$srcCont}/{$srcRel}" !== "{$dstCont}/{$dstRel}" ) {
 441                         $reqs[] = array(
 442                                 'method' => 'DELETE',
 443                                 'url' => array( $srcCont, $srcRel ),
 444                                 'headers' => array()
 445                         );
 446                 }
 447
 448                 $that = $this;
 449                 $method = __METHOD__;
 450                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 451                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 452                         if ( $request['method'] === 'PUT' && $rcode === 201 ) {
 453                                 // good
 454                         } elseif ( $request['method'] === 'DELETE' && $rcode === 204 ) {
 455                                 // good
 456                         } elseif ( $rcode === 404 ) {
 457                                 $status->fatal( 'backend-fail-move', $params['src'], $params['dst'] );
 458                         } else {
 459                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 460                         }
 461                 };
 462
 463                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 464                 if ( !empty( $params['async'] ) ) { // deferred
 465                         $status->value = $opHandle;
 466                 } else { // actually move the object in Swift
 467                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 468                 }
 469
 470                 return $status;
 471         }
 472
 473         protected function doDeleteInternal( array $params ) {
 474                 $status = Status::newGood();
 475
 476                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
 477                 if ( $srcRel === null ) {
 478                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 479
 480                         return $status;
 481                 }
 482
 483                 $reqs = array( array(
 484                         'method' => 'DELETE',
 485                         'url' => array( $srcCont, $srcRel ),
 486                         'headers' => array()
 487                 ) );
 488
 489                 $that = $this;
 490                 $method = __METHOD__;
 491                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 492                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 493                         if ( $rcode === 204 ) {
 494                                 // good
 495                         } elseif ( $rcode === 404 ) {
 496                                 if ( empty( $params['ignoreMissingSource'] ) ) {
 497                                         $status->fatal( 'backend-fail-delete', $params['src'] );
 498                                 }
 499                         } else {
 500                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 501                         }
 502                 };
 503
 504                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 505                 if ( !empty( $params['async'] ) ) { // deferred
 506                         $status->value = $opHandle;
 507                 } else { // actually delete the object in Swift
 508                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 509                 }
 510
 511                 return $status;
 512         }
 513
 514         protected function doDescribeInternal( array $params ) {
 515                 $status = Status::newGood();
 516
 517                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
 518                 if ( $srcRel === null ) {
 519                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 520
 521                         return $status;
 522                 }
 523
 524                 // Fetch the old object headers/metadata...this should be in stat cache by now
 525                 $stat = $this->getFileStat( array( 'src' => $params['src'], 'latest' => 1 ) );
 526                 if ( $stat && !isset( $stat['xattr'] ) ) { // older cache entry
 527                         $stat = $this->doGetFileStat( array( 'src' => $params['src'], 'latest' => 1 ) );
 528                 }
 529                 if ( !$stat ) {
 530                         $status->fatal( 'backend-fail-describe', $params['src'] );
 531
 532                         return $status;
 533                 }
 534
 535                 // POST clears prior headers, so we need to merge the changes in to the old ones
 536                 $metaHdrs = array();
 537                 foreach ( $stat['xattr']['metadata'] as $name => $value ) {
 538                         $metaHdrs["x-object-meta-$name"] = $value;
 539                 }
 540                 $customHdrs = $this->sanitizeHdrs( $params ) + $stat['xattr']['headers'];
 541
 542                 $reqs = array( array(
 543                         'method' => 'POST',
 544                         'url' => array( $srcCont, $srcRel ),
 545                         'headers' => $metaHdrs + $customHdrs
 546                 ) );
 547
 548                 $that = $this;
 549                 $method = __METHOD__;
 550                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 551                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 552                         if ( $rcode === 202 ) {
 553                                 // good
 554                         } elseif ( $rcode === 404 ) {
 555                                 $status->fatal( 'backend-fail-describe', $params['src'] );
 556                         } else {
 557                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 558                         }
 559                 };
 560
 561                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 562                 if ( !empty( $params['async'] ) ) { // deferred
 563                         $status->value = $opHandle;
 564                 } else { // actually change the object in Swift
 565                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 566                 }
 567
 568                 return $status;
 569         }
 570
 571         protected function doPrepareInternal( $fullCont, $dir, array $params ) {
 572                 $status = Status::newGood();
 573
 574                 // (a) Check if container already exists
 575                 $stat = $this->getContainerStat( $fullCont );
 576                 if ( is_array( $stat ) ) {
 577                         return $status; // already there
 578                 } elseif ( $stat === null ) {
 579                         $status->fatal( 'backend-fail-internal', $this->name );
 580                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': cannot get container stat' );
 581
 582                         return $status;
 583                 }
 584
 585                 // (b) Create container as needed with proper ACLs
 586                 if ( $stat === false ) {
 587                         $params['op'] = 'prepare';
 588                         $status->merge( $this->createContainer( $fullCont, $params ) );
 589                 }
 590
 591                 return $status;
 592         }
 593
 594         protected function doSecureInternal( $fullCont, $dir, array $params ) {
 595                 $status = Status::newGood();
 596                 if ( empty( $params['noAccess'] ) ) {
 597                         return $status; // nothing to do
 598                 }
 599
 600                 $stat = $this->getContainerStat( $fullCont );
 601                 if ( is_array( $stat ) ) {
 602                         // Make container private to end-users...
 603                         $status->merge( $this->setContainerAccess(
 604                                 $fullCont,
 605                                 array( $this->swiftUser ), // read
 606                                 array( $this->swiftUser ) // write
 607                         ) );
 608                 } elseif ( $stat === false ) {
 609                         $status->fatal( 'backend-fail-usable', $params['dir'] );
 610                 } else {
 611                         $status->fatal( 'backend-fail-internal', $this->name );
 612                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': cannot get container stat' );
 613                 }
 614
 615                 return $status;
 616         }
 617
 618         protected function doPublishInternal( $fullCont, $dir, array $params ) {
 619                 $status = Status::newGood();
 620
 621                 $stat = $this->getContainerStat( $fullCont );
 622                 if ( is_array( $stat ) ) {
 623                         // Make container public to end-users...
 624                         $status->merge( $this->setContainerAccess(
 625                                 $fullCont,
 626                                 array( $this->swiftUser, '.r:*' ), // read
 627                                 array( $this->swiftUser ) // write
 628                         ) );
 629                 } elseif ( $stat === false ) {
 630                         $status->fatal( 'backend-fail-usable', $params['dir'] );
 631                 } else {
 632                         $status->fatal( 'backend-fail-internal', $this->name );
 633                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': cannot get container stat' );
 634                 }
 635
 636                 return $status;
 637         }
 638
 639         protected function doCleanInternal( $fullCont, $dir, array $params ) {
 640                 $status = Status::newGood();
 641
 642                 // Only containers themselves can be removed, all else is virtual
 643                 if ( $dir != '' ) {
 644                         return $status; // nothing to do
 645                 }
 646
 647                 // (a) Check the container
 648                 $stat = $this->getContainerStat( $fullCont, true );
 649                 if ( $stat === false ) {
 650                         return $status; // ok, nothing to do
 651                 } elseif ( !is_array( $stat ) ) {
 652                         $status->fatal( 'backend-fail-internal', $this->name );
 653                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': cannot get container stat' );
 654
 655                         return $status;
 656                 }
 657
 658                 // (b) Delete the container if empty
 659                 if ( $stat['count'] == 0 ) {
 660                         $params['op'] = 'clean';
 661                         $status->merge( $this->deleteContainer( $fullCont, $params ) );
 662                 }
 663
 664                 return $status;
 665         }
 666
 667         protected function doGetFileStat( array $params ) {
 668                 $params = array( 'srcs' => array( $params['src'] ), 'concurrency' => 1 ) + $params;
 669                 unset( $params['src'] );
 670                 $stats = $this->doGetFileStatMulti( $params );
 671
 672                 return reset( $stats );
 673         }
 674
 675         /**
 676          * Convert dates like "Tue, 03 Jan 2012 22:01:04 GMT"/"2013-05-11T07:37:27.678360Z".
 677          * Dates might also come in like "2013-05-11T07:37:27.678360" from Swift listings,
 678          * missing the timezone suffix (though Ceph RGW does not appear to have this bug).
 679          *
 680          * @param string $ts
 681          * @param int $format Output format (TS_* constant)
 682          * @return string
 683          * @throws FileBackendError
 684          */
 685         protected function convertSwiftDate( $ts, $format = TS_MW ) {
 686                 try {
 687                         $timestamp = new MWTimestamp( $ts );
 688
 689                         return $timestamp->getTimestamp( $format );
 690                 } catch ( Exception $e ) {
 691                         throw new FileBackendError( $e->getMessage() );
 692                 }
 693         }
 694
 695         /**
 696          * Fill in any missing object metadata and save it to Swift
 697          *
 698          * @param array $objHdrs Object response headers
 699          * @param string $path Storage path to object
 700          * @return array New headers
 701          */
 702         protected function addMissingMetadata( array $objHdrs, $path ) {
 703                 if ( isset( $objHdrs['x-object-meta-sha1base36'] ) ) {
 704                         return $objHdrs; // nothing to do
 705                 }
 706
 707                 /** @noinspection PhpUnusedLocalVariableInspection */
 708                 $ps = Profiler::instance()->scopedProfileIn( __METHOD__ . "-{$this->name}" );
 709                 wfDebugLog( 'SwiftBackend', __METHOD__ . ": $path was not stored with SHA-1 metadata." );
 710
 711                 $objHdrs['x-object-meta-sha1base36'] = false;
 712
 713                 $auth = $this->getAuthentication();
 714                 if ( !$auth ) {
 715                         return $objHdrs; // failed
 716                 }
 717
 718                 // Find prior custom HTTP headers
 719                 $postHeaders = $this->getCustomHeaders( $objHdrs );
 720                 // Find prior metadata headers
 721                 $postHeaders += $this->getMetadataHeaders( $objHdrs );
 722
 723                 $status = Status::newGood();
 724                 /** @noinspection PhpUnusedLocalVariableInspection */
 725                 $scopeLockS = $this->getScopedFileLocks( array( $path ), LockManager::LOCK_UW, $status );
 726                 if ( $status->isOK() ) {
 727                         $tmpFile = $this->getLocalCopy( array( 'src' => $path, 'latest' => 1 ) );
 728                         if ( $tmpFile ) {
 729                                 $hash = $tmpFile->getSha1Base36();
 730                                 if ( $hash !== false ) {
 731                                         $objHdrs['x-object-meta-sha1base36'] = $hash;
 732                                         // Merge new SHA1 header into the old ones
 733                                         $postHeaders['x-object-meta-sha1base36'] = $hash;
 734                                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
 735                                         list( $rcode ) = $this->http->run( array(
 736                                                 'method' => 'POST',
 737                                                 'url' => $this->storageUrl( $auth, $srcCont, $srcRel ),
 738                                                 'headers' => $this->authTokenHeaders( $auth ) + $postHeaders
 739                                         ) );
 740                                         if ( $rcode >= 200 && $rcode <= 299 ) {
 741                                                 $this->deleteFileCache( $path );
 742
 743                                                 return $objHdrs; // success
 744                                         }
 745                                 }
 746                         }
 747                 }
 748
 749                 wfDebugLog( 'SwiftBackend', __METHOD__ . ": unable to set SHA-1 metadata for $path" );
 750
 751                 return $objHdrs; // failed
 752         }
 753
 754         protected function doGetFileContentsMulti( array $params ) {
 755                 $contents = array();
 756
 757                 $auth = $this->getAuthentication();
 758
 759                 $ep = array_diff_key( $params, array( 'srcs' => 1 ) ); // for error logging
 760                 // Blindly create tmp files and stream to them, catching any exception if the file does
 761                 // not exist. Doing stats here is useless and will loop infinitely in addMissingMetadata().
 762                 $reqs = array(); // (path => op)
 763
 764                 foreach ( $params['srcs'] as $path ) { // each path in this concurrent batch
 765                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
 766                         if ( $srcRel === null || !$auth ) {
 767                                 $contents[$path] = false;
 768                                 continue;
 769                         }
 770                         // Create a new temporary memory file...
 771                         $handle = fopen( 'php://temp', 'wb' );
 772                         if ( $handle ) {
 773                                 $reqs[$path] = array(
 774                                         'method'  => 'GET',
 775                                         'url'     => $this->storageUrl( $auth, $srcCont, $srcRel ),
 776                                         'headers' => $this->authTokenHeaders( $auth )
 777                                                 + $this->headersFromParams( $params ),
 778                                         'stream'  => $handle,
 779                                 );
 780                         }
 781                         $contents[$path] = false;
 782                 }
 783
 784                 $opts = array( 'maxConnsPerHost' => $params['concurrency'] );
 785                 $reqs = $this->http->runMulti( $reqs, $opts );
 786                 foreach ( $reqs as $path => $op ) {
 787                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $op['response'];
 788                         if ( $rcode >= 200 && $rcode <= 299 ) {
 789                                 rewind( $op['stream'] ); // start from the beginning
 790                                 $contents[$path] = stream_get_contents( $op['stream'] );
 791                         } elseif ( $rcode === 404 ) {
 792                                 $contents[$path] = false;
 793                         } else {
 794                                 $this->onError( null, __METHOD__,
 795                                         array( 'src' => $path ) + $ep, $rerr, $rcode, $rdesc );
 796                         }
 797                         fclose( $op['stream'] ); // close open handle
 798                 }
 799
 800                 return $contents;
 801         }
 802
 803         protected function doDirectoryExists( $fullCont, $dir, array $params ) {
 804                 $prefix = ( $dir == '' ) ? null : "{$dir}/";
 805                 $status = $this->objectListing( $fullCont, 'names', 1, null, $prefix );
 806                 if ( $status->isOk() ) {
 807                         return ( count( $status->value ) ) > 0;
 808                 }
 809
 810                 return null; // error
 811         }
 812
 813         /**
 814          * @see FileBackendStore::getDirectoryListInternal()
 815          * @param string $fullCont
 816          * @param string $dir
 817          * @param array $params
 818          * @return SwiftFileBackendDirList
 819          */
 820         public function getDirectoryListInternal( $fullCont, $dir, array $params ) {
 821                 return new SwiftFileBackendDirList( $this, $fullCont, $dir, $params );
 822         }
 823
 824         /**
 825          * @see FileBackendStore::getFileListInternal()
 826          * @param string $fullCont
 827          * @param string $dir
 828          * @param array $params
 829          * @return SwiftFileBackendFileList
 830          */
 831         public function getFileListInternal( $fullCont, $dir, array $params ) {
 832                 return new SwiftFileBackendFileList( $this, $fullCont, $dir, $params );
 833         }
 834
 835         /**
 836          * Do not call this function outside of SwiftFileBackendFileList
 837          *
 838          * @param string $fullCont Resolved container name
 839          * @param string $dir Resolved storage directory with no trailing slash
 840          * @param string|null $after Resolved container relative path to list items after
 841          * @param int $limit Max number of items to list
 842          * @param array $params Parameters for getDirectoryList()
 843          * @return array List of container relative resolved paths of directories directly under $dir
 844          * @throws FileBackendError
 845          */
 846         public function getDirListPageInternal( $fullCont, $dir, &$after, $limit, array $params ) {
 847                 $dirs = array();
 848                 if ( $after === INF ) {
 849                         return $dirs; // nothing more
 850                 }
 851
 852                 $ps = Profiler::instance()->scopedProfileIn( __METHOD__ . "-{$this->name}" );
 853
 854                 $prefix = ( $dir == '' ) ? null : "{$dir}/";
 855                 // Non-recursive: only list dirs right under $dir
 856                 if ( !empty( $params['topOnly'] ) ) {
 857                         $status = $this->objectListing( $fullCont, 'names', $limit, $after, $prefix, '/' );
 858                         if ( !$status->isOk() ) {
 859                                 return $dirs; // error
 860                         }
 861                         $objects = $status->value;
 862                         foreach ( $objects as $object ) { // files and directories
 863                                 if ( substr( $object, -1 ) === '/' ) {
 864                                         $dirs[] = $object; // directories end in '/'
 865                                 }
 866                         }
 867                 } else {
 868                         // Recursive: list all dirs under $dir and its subdirs
 869                         $getParentDir = function ( $path ) {
 870                                 return ( strpos( $path, '/' ) !== false ) ? dirname( $path ) : false;
 871                         };
 872
 873                         // Get directory from last item of prior page
 874                         $lastDir = $getParentDir( $after ); // must be first page
 875                         $status = $this->objectListing( $fullCont, 'names', $limit, $after, $prefix );
 876
 877                         if ( !$status->isOk() ) {
 878                                 return $dirs; // error
 879                         }
 880
 881                         $objects = $status->value;
 882
 883                         foreach ( $objects as $object ) { // files
 884                                 $objectDir = $getParentDir( $object ); // directory of object
 885
 886                                 if ( $objectDir !== false && $objectDir !== $dir ) {
 887                                         // Swift stores paths in UTF-8, using binary sorting.
 888                                         // See function "create_container_table" in common/db.py.
 889                                         // If a directory is not "greater" than the last one,
 890                                         // then it was already listed by the calling iterator.
 891                                         if ( strcmp( $objectDir, $lastDir ) > 0 ) {
 892                                                 $pDir = $objectDir;
 893                                                 do { // add dir and all its parent dirs
 894                                                         $dirs[] = "{$pDir}/";
 895                                                         $pDir = $getParentDir( $pDir );
 896                                                 } while ( $pDir !== false // sanity
 897                                                         && strcmp( $pDir, $lastDir ) > 0 // not done already
 898                                                         && strlen( $pDir ) > strlen( $dir ) // within $dir
 899                                                 );
 900                                         }
 901                                         $lastDir = $objectDir;
 902                                 }
 903                         }
 904                 }
 905                 // Page on the unfiltered directory listing (what is returned may be filtered)
 906                 if ( count( $objects ) < $limit ) {
 907                         $after = INF; // avoid a second RTT
 908                 } else {
 909                         $after = end( $objects ); // update last item
 910                 }
 911
 912                 return $dirs;
 913         }
 914
 915         /**
 916          * Do not call this function outside of SwiftFileBackendFileList
 917          *
 918          * @param string $fullCont Resolved container name
 919          * @param string $dir Resolved storage directory with no trailing slash
 920          * @param string|null $after Resolved container relative path of file to list items after
 921          * @param int $limit Max number of items to list
 922          * @param array $params Parameters for getDirectoryList()
 923          * @return array List of resolved container relative paths of files under $dir
 924          * @throws FileBackendError
 925          */
 926         public function getFileListPageInternal( $fullCont, $dir, &$after, $limit, array $params ) {
 927                 $files = array(); // list of (path, stat array or null) entries
 928                 if ( $after === INF ) {
 929                         return $files; // nothing more
 930                 }
 931
 932                 $ps = Profiler::instance()->scopedProfileIn( __METHOD__ . "-{$this->name}" );
 933
 934                 $prefix = ( $dir == '' ) ? null : "{$dir}/";
 935                 // $objects will contain a list of unfiltered names or CF_Object items
 936                 // Non-recursive: only list files right under $dir
 937                 if ( !empty( $params['topOnly'] ) ) {
 938                         if ( !empty( $params['adviseStat'] ) ) {
 939                                 $status = $this->objectListing( $fullCont, 'info', $limit, $after, $prefix, '/' );
 940                         } else {
 941                                 $status = $this->objectListing( $fullCont, 'names', $limit, $after, $prefix, '/' );
 942                         }
 943                 } else {
 944                         // Recursive: list all files under $dir and its subdirs
 945                         if ( !empty( $params['adviseStat'] ) ) {
 946                                 $status = $this->objectListing( $fullCont, 'info', $limit, $after, $prefix );
 947                         } else {
 948                                 $status = $this->objectListing( $fullCont, 'names', $limit, $after, $prefix );
 949                         }
 950                 }
 951
 952                 // Reformat this list into a list of (name, stat array or null) entries
 953                 if ( !$status->isOk() ) {
 954                         return $files; // error
 955                 }
 956
 957                 $objects = $status->value;
 958                 $files = $this->buildFileObjectListing( $params, $dir, $objects );
 959
 960                 // Page on the unfiltered object listing (what is returned may be filtered)
 961                 if ( count( $objects ) < $limit ) {
 962                         $after = INF; // avoid a second RTT
 963                 } else {
 964                         $after = end( $objects ); // update last item
 965                         $after = is_object( $after ) ? $after->name : $after;
 966                 }
 967
 968                 return $files;
 969         }
 970
 971         /**
 972          * Build a list of file objects, filtering out any directories
 973          * and extracting any stat info if provided in $objects (for CF_Objects)
 974          *
 975          * @param array $params Parameters for getDirectoryList()
 976          * @param string $dir Resolved container directory path
 977          * @param array $objects List of CF_Object items or object names
 978          * @return array List of (names,stat array or null) entries
 979          */
 980         private function buildFileObjectListing( array $params, $dir, array $objects ) {
 981                 $names = array();
 982                 foreach ( $objects as $object ) {
 983                         if ( is_object( $object ) ) {
 984                                 if ( isset( $object->subdir ) || !isset( $object->name ) ) {
 985                                         continue; // virtual directory entry; ignore
 986                                 }
 987                                 $stat = array(
 988                                         // Convert various random Swift dates to TS_MW
 989                                         'mtime'  => $this->convertSwiftDate( $object->last_modified, TS_MW ),
 990                                         'size'   => (int)$object->bytes,
 991                                         'sha1'   => null,
 992                                         // Note: manifiest ETags are not an MD5 of the file
 993                                         'md5'    => ctype_xdigit( $object->hash ) ? $object->hash : null,
 994                                         'latest' => false // eventually consistent
 995                                 );
 996                                 $names[] = array( $object->name, $stat );
 997                         } elseif ( substr( $object, -1 ) !== '/' ) {
 998                                 // Omit directories, which end in '/' in listings
 999                                 $names[] = array( $object, null );
1000                         }
1001                 }
1002
1003                 return $names;
1004         }
1005
1006         /**
1007          * Do not call this function outside of SwiftFileBackendFileList
1008          *
1009          * @param string $path Storage path
1010          * @param array $val Stat value
1011          */
1012         public function loadListingStatInternal( $path, array $val ) {
1013                 $this->cheapCache->set( $path, 'stat', $val );
1014         }
1015
1016         protected function doGetFileXAttributes( array $params ) {
1017                 $stat = $this->getFileStat( $params );
1018                 if ( $stat ) {
1019                         if ( !isset( $stat['xattr'] ) ) {
1020                                 // Stat entries filled by file listings don't include metadata/headers
1021                                 $this->clearCache( array( $params['src'] ) );
1022                                 $stat = $this->getFileStat( $params );
1023                         }
1024
1025                         return $stat['xattr'];
1026                 } else {
1027                         return false;
1028                 }
1029         }
1030
1031         protected function doGetFileSha1base36( array $params ) {
1032                 $stat = $this->getFileStat( $params );
1033                 if ( $stat ) {
1034                         if ( !isset( $stat['sha1'] ) ) {
1035                                 // Stat entries filled by file listings don't include SHA1
1036                                 $this->clearCache( array( $params['src'] ) );
1037                                 $stat = $this->getFileStat( $params );
1038                         }
1039
1040                         return $stat['sha1'];
1041                 } else {
1042                         return false;
1043                 }
1044         }
1045
1046         protected function doStreamFile( array $params ) {
1047                 $status = Status::newGood();
1048
1049                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
1050                 if ( $srcRel === null ) {
1051                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
1052                 }
1053
1054                 $auth = $this->getAuthentication();
1055                 if ( !$auth || !is_array( $this->getContainerStat( $srcCont ) ) ) {
1056                         $status->fatal( 'backend-fail-stream', $params['src'] );
1057
1058                         return $status;
1059                 }
1060
1061                 $handle = fopen( 'php://output', 'wb' );
1062
1063                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1064                         'method' => 'GET',
1065                         'url' => $this->storageUrl( $auth, $srcCont, $srcRel ),
1066                         'headers' => $this->authTokenHeaders( $auth )
1067                                 + $this->headersFromParams( $params ),
1068                         'stream' => $handle,
1069                 ) );
1070
1071                 if ( $rcode >= 200 && $rcode <= 299 ) {
1072                         // good
1073                 } elseif ( $rcode === 404 ) {
1074                         $status->fatal( 'backend-fail-stream', $params['src'] );
1075                 } else {
1076                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc );
1077                 }
1078
1079                 return $status;
1080         }
1081
1082         protected function doGetLocalCopyMulti( array $params ) {
1083                 $tmpFiles = array();
1084
1085                 $auth = $this->getAuthentication();
1086
1087                 $ep = array_diff_key( $params, array( 'srcs' => 1 ) ); // for error logging
1088                 // Blindly create tmp files and stream to them, catching any exception if the file does
1089                 // not exist. Doing a stat here is useless causes infinite loops in addMissingMetadata().
1090                 $reqs = array(); // (path => op)
1091
1092                 foreach ( $params['srcs'] as $path ) { // each path in this concurrent batch
1093                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
1094                         if ( $srcRel === null || !$auth ) {
1095                                 $tmpFiles[$path] = null;
1096                                 continue;
1097                         }
1098                         // Get source file extension
1099                         $ext = FileBackend::extensionFromPath( $path );
1100                         // Create a new temporary file...
1101                         $tmpFile = TempFSFile::factory( 'localcopy_', $ext );
1102                         if ( $tmpFile ) {
1103                                 $handle = fopen( $tmpFile->getPath(), 'wb' );
1104                                 if ( $handle ) {
1105                                         $reqs[$path] = array(
1106                                                 'method'  => 'GET',
1107                                                 'url'     => $this->storageUrl( $auth, $srcCont, $srcRel ),
1108                                                 'headers' => $this->authTokenHeaders( $auth )
1109                                                         + $this->headersFromParams( $params ),
1110                                                 'stream'  => $handle,
1111                                         );
1112                                 } else {
1113                                         $tmpFile = null;
1114                                 }
1115                         }
1116                         $tmpFiles[$path] = $tmpFile;
1117                 }
1118
1119                 $isLatest = ( $this->isRGW || !empty( $params['latest'] ) );
1120                 $opts = array( 'maxConnsPerHost' => $params['concurrency'] );
1121                 $reqs = $this->http->runMulti( $reqs, $opts );
1122                 foreach ( $reqs as $path => $op ) {
1123                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $op['response'];
1124                         fclose( $op['stream'] ); // close open handle
1125                         if ( $rcode >= 200 && $rcode <= 299 ) {
1126                                 $size = $tmpFiles[$path] ? $tmpFiles[$path]->getSize() : 0;
1127                                 // Double check that the disk is not full/broken
1128                                 if ( $size != $rhdrs['content-length'] ) {
1129                                         $tmpFiles[$path] = null;
1130                                         $rerr = "Got {$size}/{$rhdrs['content-length']} bytes";
1131                                         $this->onError( null, __METHOD__,
1132                                                 array( 'src' => $path ) + $ep, $rerr, $rcode, $rdesc );
1133                                 }
1134                                 // Set the file stat process cache in passing
1135                                 $stat = $this->getStatFromHeaders( $rhdrs );
1136                                 $stat['latest'] = $isLatest;
1137                                 $this->cheapCache->set( $path, 'stat', $stat );
1138                         } elseif ( $rcode === 404 ) {
1139                                 $tmpFiles[$path] = false;
1140                         } else {
1141                                 $tmpFiles[$path] = null;
1142                                 $this->onError( null, __METHOD__,
1143                                         array( 'src' => $path ) + $ep, $rerr, $rcode, $rdesc );
1144                         }
1145                 }
1146
1147                 return $tmpFiles;
1148         }
1149
1150         public function getFileHttpUrl( array $params ) {
1151                 if ( $this->swiftTempUrlKey != '' ||
1152                         ( $this->rgwS3AccessKey != '' && $this->rgwS3SecretKey != '' )
1153                 ) {
1154                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
1155                         if ( $srcRel === null ) {
1156                                 return null; // invalid path
1157                         }
1158
1159                         $auth = $this->getAuthentication();
1160                         if ( !$auth ) {
1161                                 return null;
1162                         }
1163
1164                         $ttl = isset( $params['ttl'] ) ? $params['ttl'] : 86400;
1165                         $expires = time() + $ttl;
1166
1167                         if ( $this->swiftTempUrlKey != '' ) {
1168                                 $url = $this->storageUrl( $auth, $srcCont, $srcRel );
1169                                 // Swift wants the signature based on the unencoded object name
1170                                 $contPath = parse_url( $this->storageUrl( $auth, $srcCont ), PHP_URL_PATH );
1171                                 $signature = hash_hmac( 'sha1',
1172                                         "GET\n{$expires}\n{$contPath}/{$srcRel}",
1173                                         $this->swiftTempUrlKey
1174                                 );
1175
1176                                 return "{$url}?temp_url_sig={$signature}&temp_url_expires={$expires}";
1177                         } else { // give S3 API URL for rgw
1178                                 // Path for signature starts with the bucket
1179                                 $spath = '/' . rawurlencode( $srcCont ) . '/' .
1180                                         str_replace( '%2F', '/', rawurlencode( $srcRel ) );
1181                                 // Calculate the hash
1182                                 $signature = base64_encode( hash_hmac(
1183                                         'sha1',
1184                                         "GET\n\n\n{$expires}\n{$spath}",
1185                                         $this->rgwS3SecretKey,
1186                                         true // raw
1187                                 ) );
1188                                 // See http://s3.amazonaws.com/doc/s3-developer-guide/RESTAuthentication.html.
1189                                 // Note: adding a newline for empty CanonicalizedAmzHeaders does not work.
1190                                 return wfAppendQuery(
1191                                         str_replace( '/swift/v1', '', // S3 API is the rgw default
1192                                                 $this->storageUrl( $auth ) . $spath ),
1193                                         array(
1194                                                 'Signature' => $signature,
1195                                                 'Expires' => $expires,
1196                                                 'AWSAccessKeyId' => $this->rgwS3AccessKey )
1197                                 );
1198                         }
1199                 }
1200
1201                 return null;
1202         }
1203
1204         protected function directoriesAreVirtual() {
1205                 return true;
1206         }
1207
1208         /**
1209          * Get headers to send to Swift when reading a file based
1210          * on a FileBackend params array, e.g. that of getLocalCopy().
1211          * $params is currently only checked for a 'latest' flag.
1212          *
1213          * @param array $params
1214          * @return array
1215          */
1216         protected function headersFromParams( array $params ) {
1217                 $hdrs = array();
1218                 if ( !empty( $params['latest'] ) ) {
1219                         $hdrs['x-newest'] = 'true';
1220                 }
1221
1222                 return $hdrs;
1223         }
1224
1225         /**
1226          * @param FileBackendStoreOpHandle[] $fileOpHandles
1227          *
1228          * @return Status[]
1229          */
1230         protected function doExecuteOpHandlesInternal( array $fileOpHandles ) {
1231                 $statuses = array();
1232
1233                 $auth = $this->getAuthentication();
1234                 if ( !$auth ) {
1235                         foreach ( $fileOpHandles as $index => $fileOpHandle ) {
1236                                 $statuses[$index] = Status::newFatal( 'backend-fail-connect', $this->name );
1237                         }
1238
1239                         return $statuses;
1240                 }
1241
1242                 // Split the HTTP requests into stages that can be done concurrently
1243                 $httpReqsByStage = array(); // map of (stage => index => HTTP request)
1244                 foreach ( $fileOpHandles as $index => $fileOpHandle ) {
1245                         $reqs = $fileOpHandle->httpOp;
1246                         // Convert the 'url' parameter to an actual URL using $auth
1247                         foreach ( $reqs as $stage => &$req ) {
1248                                 list( $container, $relPath ) = $req['url'];
1249                                 $req['url'] = $this->storageUrl( $auth, $container, $relPath );
1250                                 $req['headers'] = isset( $req['headers'] ) ? $req['headers'] : array();
1251                                 $req['headers'] = $this->authTokenHeaders( $auth ) + $req['headers'];
1252                                 $httpReqsByStage[$stage][$index] = $req;
1253                         }
1254                         $statuses[$index] = Status::newGood();
1255                 }
1256
1257                 // Run all requests for the first stage, then the next, and so on
1258                 $reqCount = count( $httpReqsByStage );
1259                 for ( $stage = 0; $stage < $reqCount; ++$stage ) {
1260                         $httpReqs = $this->http->runMulti( $httpReqsByStage[$stage] );
1261                         foreach ( $httpReqs as $index => $httpReq ) {
1262                                 // Run the callback for each request of this operation
1263                                 $callback = $fileOpHandles[$index]->callback;
1264                                 call_user_func_array( $callback, array( $httpReq, $statuses[$index] ) );
1265                                 // On failure, abort all remaining requests for this operation
1266                                 // (e.g. abort the DELETE request if the COPY request fails for a move)
1267                                 if ( !$statuses[$index]->isOK() ) {
1268                                         $stages = count( $fileOpHandles[$index]->httpOp );
1269                                         for ( $s = ( $stage + 1 ); $s < $stages; ++$s ) {
1270                                                 unset( $httpReqsByStage[$s][$index] );
1271                                         }
1272                                 }
1273                         }
1274                 }
1275
1276                 return $statuses;
1277         }
1278
1279         /**
1280          * Set read/write permissions for a Swift container.
1281          *
1282          * @see http://swift.openstack.org/misc.html#acls
1283          *
1284          * In general, we don't allow listings to end-users. It's not useful, isn't well-defined
1285          * (lists are truncated to 10000 item with no way to page), and is just a performance risk.
1286          *
1287          * @param string $container Resolved Swift container
1288          * @param array $readGrps List of the possible criteria for a request to have
1289          * access to read a container. Each item is one of the following formats:
1290          *   - account:user        : Grants access if the request is by the given user
1291          *   - ".r:<regex>"        : Grants access if the request is from a referrer host that
1292          *                           matches the expression and the request is not for a listing.
1293          *                           Setting this to '*' effectively makes a container public.
1294          *   -".rlistings:<regex>" : Grants access if the request is from a referrer host that
1295          *                           matches the expression and the request is for a listing.
1296          * @param array $writeGrps A list of the possible criteria for a request to have
1297          * access to write to a container. Each item is of the following format:
1298          *   - account:user       : Grants access if the request is by the given user
1299          * @return Status
1300          */
1301         protected function setContainerAccess( $container, array $readGrps, array $writeGrps ) {
1302                 $status = Status::newGood();
1303                 $auth = $this->getAuthentication();
1304
1305                 if ( !$auth ) {
1306                         $status->fatal( 'backend-fail-connect', $this->name );
1307
1308                         return $status;
1309                 }
1310
1311                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1312                         'method' => 'POST',
1313                         'url' => $this->storageUrl( $auth, $container ),
1314                         'headers' => $this->authTokenHeaders( $auth ) + array(
1315                                 'x-container-read' => implode( ',', $readGrps ),
1316                                 'x-container-write' => implode( ',', $writeGrps )
1317                         )
1318                 ) );
1319
1320                 if ( $rcode != 204 && $rcode !== 202 ) {
1321                         $status->fatal( 'backend-fail-internal', $this->name );
1322                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': unexpected rcode value (' . $rcode . ')' );
1323                 }
1324
1325                 return $status;
1326         }
1327
1328         /**
1329          * Get a Swift container stat array, possibly from process cache.
1330          * Use $reCache if the file count or byte count is needed.
1331          *
1332          * @param string $container Container name
1333          * @param bool $bypassCache Bypass all caches and load from Swift
1334          * @return array|bool|null False on 404, null on failure
1335          */
1336         protected function getContainerStat( $container, $bypassCache = false ) {
1337                 $ps = Profiler::instance()->scopedProfileIn( __METHOD__ . "-{$this->name}" );
1338
1339                 if ( $bypassCache ) { // purge cache
1340                         $this->containerStatCache->clear( $container );
1341                 } elseif ( !$this->containerStatCache->has( $container, 'stat' ) ) {
1342                         $this->primeContainerCache( array( $container ) ); // check persistent cache
1343                 }
1344                 if ( !$this->containerStatCache->has( $container, 'stat' ) ) {
1345                         $auth = $this->getAuthentication();
1346                         if ( !$auth ) {
1347                                 return null;
1348                         }
1349
1350                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1351                                 'method' => 'HEAD',
1352                                 'url' => $this->storageUrl( $auth, $container ),
1353                                 'headers' => $this->authTokenHeaders( $auth )
1354                         ) );
1355
1356                         if ( $rcode === 204 ) {
1357                                 $stat = array(
1358                                         'count' => $rhdrs['x-container-object-count'],
1359                                         'bytes' => $rhdrs['x-container-bytes-used']
1360                                 );
1361                                 if ( $bypassCache ) {
1362                                         return $stat;
1363                                 } else {
1364                                         $this->containerStatCache->set( $container, 'stat', $stat ); // cache it
1365                                         $this->setContainerCache( $container, $stat ); // update persistent cache
1366                                 }
1367                         } elseif ( $rcode === 404 ) {
1368                                 return false;
1369                         } else {
1370                                 $this->onError( null, __METHOD__,
1371                                         array( 'cont' => $container ), $rerr, $rcode, $rdesc );
1372
1373                                 return null;
1374                         }
1375                 }
1376
1377                 return $this->containerStatCache->get( $container, 'stat' );
1378         }
1379
1380         /**
1381          * Create a Swift container
1382          *
1383          * @param string $container Container name
1384          * @param array $params
1385          * @return Status
1386          */
1387         protected function createContainer( $container, array $params ) {
1388                 $status = Status::newGood();
1389
1390                 $auth = $this->getAuthentication();
1391                 if ( !$auth ) {
1392                         $status->fatal( 'backend-fail-connect', $this->name );
1393
1394                         return $status;
1395                 }
1396
1397                 // @see SwiftFileBackend::setContainerAccess()
1398                 if ( empty( $params['noAccess'] ) ) {
1399                         $readGrps = array( '.r:*', $this->swiftUser ); // public
1400                 } else {
1401                         $readGrps = array( $this->swiftUser ); // private
1402                 }
1403                 $writeGrps = array( $this->swiftUser ); // sanity
1404
1405                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1406                         'method' => 'PUT',
1407                         'url' => $this->storageUrl( $auth, $container ),
1408                         'headers' => $this->authTokenHeaders( $auth ) + array(
1409                                 'x-container-read' => implode( ',', $readGrps ),
1410                                 'x-container-write' => implode( ',', $writeGrps )
1411                         )
1412                 ) );
1413
1414                 if ( $rcode === 201 ) { // new
1415                         // good
1416                 } elseif ( $rcode === 202 ) { // already there
1417                         // this shouldn't really happen, but is OK
1418                 } else {
1419                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc );
1420                 }
1421
1422                 return $status;
1423         }
1424
1425         /**
1426          * Delete a Swift container
1427          *
1428          * @param string $container Container name
1429          * @param array $params
1430          * @return Status
1431          */
1432         protected function deleteContainer( $container, array $params ) {
1433                 $status = Status::newGood();
1434
1435                 $auth = $this->getAuthentication();
1436                 if ( !$auth ) {
1437                         $status->fatal( 'backend-fail-connect', $this->name );
1438
1439                         return $status;
1440                 }
1441
1442                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1443                         'method' => 'DELETE',
1444                         'url' => $this->storageUrl( $auth, $container ),
1445                         'headers' => $this->authTokenHeaders( $auth )
1446                 ) );
1447
1448                 if ( $rcode >= 200 && $rcode <= 299 ) { // deleted
1449                         $this->containerStatCache->clear( $container ); // purge
1450                 } elseif ( $rcode === 404 ) { // not there
1451                         // this shouldn't really happen, but is OK
1452                 } elseif ( $rcode === 409 ) { // not empty
1453                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc ); // race?
1454                 } else {
1455                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc );
1456                 }
1457
1458                 return $status;
1459         }
1460
1461         /**
1462          * Get a list of objects under a container.
1463          * Either just the names or a list of stdClass objects with details can be returned.
1464          *
1465          * @param string $fullCont
1466          * @param string $type ('info' for a list of object detail maps, 'names' for names only)
1467          * @param int $limit
1468          * @param string|null $after
1469          * @param string|null $prefix
1470          * @param string|null $delim
1471          * @return Status With the list as value
1472          */
1473         private function objectListing(
1474                 $fullCont, $type, $limit, $after = null, $prefix = null, $delim = null
1475         ) {
1476                 $status = Status::newGood();
1477
1478                 $auth = $this->getAuthentication();
1479                 if ( !$auth ) {
1480                         $status->fatal( 'backend-fail-connect', $this->name );
1481
1482                         return $status;
1483                 }
1484
1485                 $query = array( 'limit' => $limit );
1486                 if ( $type === 'info' ) {
1487                         $query['format'] = 'json';
1488                 }
1489                 if ( $after !== null ) {
1490                         $query['marker'] = $after;
1491                 }
1492                 if ( $prefix !== null ) {
1493                         $query['prefix'] = $prefix;
1494                 }
1495                 if ( $delim !== null ) {
1496                         $query['delimiter'] = $delim;
1497                 }
1498
1499                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1500                         'method' => 'GET',
1501                         'url' => $this->storageUrl( $auth, $fullCont ),
1502                         'query' => $query,
1503                         'headers' => $this->authTokenHeaders( $auth )
1504                 ) );
1505
1506                 $params = array( 'cont' => $fullCont, 'prefix' => $prefix, 'delim' => $delim );
1507                 if ( $rcode === 200 ) { // good
1508                         if ( $type === 'info' ) {
1509                                 $status->value = FormatJson::decode( trim( $rbody ) );
1510                         } else {
1511                                 $status->value = explode( "\n", trim( $rbody ) );
1512                         }
1513                 } elseif ( $rcode === 204 ) {
1514                         $status->value = array(); // empty container
1515                 } elseif ( $rcode === 404 ) {
1516                         $status->value = array(); // no container
1517                 } else {
1518                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc );
1519                 }
1520
1521                 return $status;
1522         }
1523
1524         protected function doPrimeContainerCache( array $containerInfo ) {
1525                 foreach ( $containerInfo as $container => $info ) {
1526                         $this->containerStatCache->set( $container, 'stat', $info );
1527                 }
1528         }
1529
1530         protected function doGetFileStatMulti( array $params ) {
1531                 $stats = array();
1532
1533                 $auth = $this->getAuthentication();
1534
1535                 $reqs = array();
1536                 foreach ( $params['srcs'] as $path ) {
1537                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
1538                         if ( $srcRel === null ) {
1539                                 $stats[$path] = false;
1540                                 continue; // invalid storage path
1541                         } elseif ( !$auth ) {
1542                                 $stats[$path] = null;
1543                                 continue;
1544                         }
1545
1546                         // (a) Check the container
1547                         $cstat = $this->getContainerStat( $srcCont );
1548                         if ( $cstat === false ) {
1549                                 $stats[$path] = false;
1550                                 continue; // ok, nothing to do
1551                         } elseif ( !is_array( $cstat ) ) {
1552                                 $stats[$path] = null;
1553                                 continue;
1554                         }
1555
1556                         $reqs[$path] = array(
1557                                 'method'  => 'HEAD',
1558                                 'url'     => $this->storageUrl( $auth, $srcCont, $srcRel ),
1559                                 'headers' => $this->authTokenHeaders( $auth ) + $this->headersFromParams( $params )
1560                         );
1561                 }
1562
1563                 $opts = array( 'maxConnsPerHost' => $params['concurrency'] );
1564                 $reqs = $this->http->runMulti( $reqs, $opts );
1565
1566                 foreach ( $params['srcs'] as $path ) {
1567                         if ( array_key_exists( $path, $stats ) ) {
1568                                 continue; // some sort of failure above
1569                         }
1570                         // (b) Check the file
1571                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $reqs[$path]['response'];
1572                         if ( $rcode === 200 || $rcode === 204 ) {
1573                                 // Update the object if it is missing some headers
1574                                 $rhdrs = $this->addMissingMetadata( $rhdrs, $path );
1575                                 // Load the stat array from the headers
1576                                 $stat = $this->getStatFromHeaders( $rhdrs );
1577                                 if ( $this->isRGW ) {
1578                                         $stat['latest'] = true; // strong consistency
1579                                 }
1580                         } elseif ( $rcode === 404 ) {
1581                                 $stat = false;
1582                         } else {
1583                                 $stat = null;
1584                                 $this->onError( null, __METHOD__, $params, $rerr, $rcode, $rdesc );
1585                         }
1586                         $stats[$path] = $stat;
1587                 }
1588
1589                 return $stats;
1590         }
1591
1592         /**
1593          * @param array $rhdrs
1594          * @return array
1595          */
1596         protected function getStatFromHeaders( array $rhdrs ) {
1597                 // Fetch all of the custom metadata headers
1598                 $metadata = $this->getMetadata( $rhdrs );
1599                 // Fetch all of the custom raw HTTP headers
1600                 $headers = $this->sanitizeHdrs( array( 'headers' => $rhdrs ) );
1601
1602                 return array(
1603                         // Convert various random Swift dates to TS_MW
1604                         'mtime' => $this->convertSwiftDate( $rhdrs['last-modified'], TS_MW ),
1605                         // Empty objects actually return no content-length header in Ceph
1606                         'size'  => isset( $rhdrs['content-length'] ) ? (int)$rhdrs['content-length'] : 0,
1607                         'sha1'  => isset( $metadata['sha1base36'] ) ? $metadata['sha1base36'] : null,
1608                         // Note: manifiest ETags are not an MD5 of the file
1609                         'md5'   => ctype_xdigit( $rhdrs['etag'] ) ? $rhdrs['etag'] : null,
1610                         'xattr' => array( 'metadata' => $metadata, 'headers' => $headers )
1611                 );
1612         }
1613
1614         /**
1615          * @return array|null Credential map
1616          */
1617         protected function getAuthentication() {
1618                 if ( $this->authErrorTimestamp !== null ) {
1619                         if ( ( time() - $this->authErrorTimestamp ) < 60 ) {
1620                                 return null; // failed last attempt; don't bother
1621                         } else { // actually retry this time
1622                                 $this->authErrorTimestamp = null;
1623                         }
1624                 }
1625                 // Session keys expire after a while, so we renew them periodically
1626                 $reAuth = ( ( time() - $this->authSessionTimestamp ) > $this->authTTL );
1627                 // Authenticate with proxy and get a session key...
1628                 if ( !$this->authCreds || $reAuth ) {
1629                         $this->authSessionTimestamp = 0;
1630                         $cacheKey = $this->getCredsCacheKey( $this->swiftUser );
1631                         $creds = $this->srvCache->get( $cacheKey ); // credentials
1632                         // Try to use the credential cache
1633                         if ( isset( $creds['auth_token'] ) && isset( $creds['storage_url'] ) ) {
1634                                 $this->authCreds = $creds;
1635                                 // Skew the timestamp for worst case to avoid using stale credentials
1636                                 $this->authSessionTimestamp = time() - ceil( $this->authTTL / 2 );
1637                         } else { // cache miss
1638                                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1639                                         'method' => 'GET',
1640                                         'url' => "{$this->swiftAuthUrl}/v1.0",
1641                                         'headers' => array(
1642                                                 'x-auth-user' => $this->swiftUser,
1643                                                 'x-auth-key' => $this->swiftKey
1644                                         )
1645                                 ) );
1646
1647                                 if ( $rcode >= 200 && $rcode <= 299 ) { // OK
1648                                         $this->authCreds = array(
1649                                                 'auth_token' => $rhdrs['x-auth-token'],
1650                                                 'storage_url' => $rhdrs['x-storage-url']
1651                                         );
1652                                         $this->srvCache->set( $cacheKey, $this->authCreds, ceil( $this->authTTL / 2 ) );
1653                                         $this->authSessionTimestamp = time();
1654                                 } elseif ( $rcode === 401 ) {
1655                                         $this->onError( null, __METHOD__, array(), "Authentication failed.", $rcode );
1656                                         $this->authErrorTimestamp = time();
1657
1658                                         return null;
1659                                 } else {
1660                                         $this->onError( null, __METHOD__, array(), "HTTP return code: $rcode", $rcode );
1661                                         $this->authErrorTimestamp = time();
1662
1663                                         return null;
1664                                 }
1665                         }
1666                         // Ceph RGW does not use <account> in URLs (OpenStack Swift uses "/v1/<account>")
1667                         if ( substr( $this->authCreds['storage_url'], -3 ) === '/v1' ) {
1668                                 $this->isRGW = true; // take advantage of strong consistency in Ceph
1669                         }
1670                 }
1671
1672                 return $this->authCreds;
1673         }
1674
1675         /**
1676          * @param array $creds From getAuthentication()
1677          * @param string $container
1678          * @param string $object
1679          * @return array
1680          */
1681         protected function storageUrl( array $creds, $container = null, $object = null ) {
1682                 $parts = array( $creds['storage_url'] );
1683                 if ( strlen( $container ) ) {
1684                         $parts[] = rawurlencode( $container );
1685                 }
1686                 if ( strlen( $object ) ) {
1687                         $parts[] = str_replace( "%2F", "/", rawurlencode( $object ) );
1688                 }
1689
1690                 return implode( '/', $parts );
1691         }
1692
1693         /**
1694          * @param array $creds From getAuthentication()
1695          * @return array
1696          */
1697         protected function authTokenHeaders( array $creds ) {
1698                 return array( 'x-auth-token' => $creds['auth_token'] );
1699         }
1700
1701         /**
1702          * Get the cache key for a container
1703          *
1704          * @param string $username
1705          * @return string
1706          */
1707         private function getCredsCacheKey( $username ) {
1708                 return 'swiftcredentials:' . md5( $username . ':' . $this->swiftAuthUrl );
1709         }
1710
1711         /**
1712          * Log an unexpected exception for this backend.
1713          * This also sets the Status object to have a fatal error.
1714          *
1715          * @param Status|null $status
1716          * @param string $func
1717          * @param array $params
1718          * @param string $err Error string
1719          * @param int $code HTTP status
1720          * @param string $desc HTTP status description
1721          */
1722         public function onError( $status, $func, array $params, $err = '', $code = 0, $desc = '' ) {
1723                 if ( $status instanceof Status ) {
1724                         $status->fatal( 'backend-fail-internal', $this->name );
1725                 }
1726                 if ( $code == 401 ) { // possibly a stale token
1727                         $this->srvCache->delete( $this->getCredsCacheKey( $this->swiftUser ) );
1728                 }
1729                 wfDebugLog( 'SwiftBackend',
1730                         "HTTP $code ($desc) in '{$func}' (given '" . FormatJson::encode( $params ) . "')" .
1731                         ( $err ? ": $err" : "" )
1732                 );
1733         }
1734 }
1735
1736 /**
1737  * @see FileBackendStoreOpHandle
1738  */
1739 class SwiftFileOpHandle extends FileBackendStoreOpHandle {
1740         /** @var array List of Requests for MultiHttpClient */
1741         public $httpOp;
1742         /** @var Closure */
1743         public $callback;
1744
1745         /**
1746          * @param SwiftFileBackend $backend
1747          * @param Closure $callback Function that takes (HTTP request array, status)
1748          * @param array $httpOp MultiHttpClient op
1749          */
1750         public function __construct( SwiftFileBackend $backend, Closure $callback, array $httpOp ) {
1751                 $this->backend = $backend;
1752                 $this->callback = $callback;
1753                 $this->httpOp = $httpOp;
1754         }
1755 }
1756
1757 /**
1758  * SwiftFileBackend helper class to page through listings.
1759  * Swift also has a listing limit of 10,000 objects for sanity.
1760  * Do not use this class from places outside SwiftFileBackend.
1761  *
1762  * @ingroup FileBackend
1763  */
1764 abstract class SwiftFileBackendList implements Iterator {
1765         /** @var array List of path or (path,stat array) entries */
1766         protected $bufferIter = array();
1767
1768         /** @var string List items *after* this path */
1769         protected $bufferAfter = null;
1770
1771         /** @var int */
1772         protected $pos = 0;
1773
1774         /** @var array */
1775         protected $params = array();
1776
1777         /** @var SwiftFileBackend */
1778         protected $backend;
1779
1780         /** @var string Container name */
1781         protected $container;
1782
1783         /** @var string Storage directory */
1784         protected $dir;
1785
1786         /** @var int */
1787         protected $suffixStart;
1788
1789         const PAGE_SIZE = 9000; // file listing buffer size
1790
1791         /**
1792          * @param SwiftFileBackend $backend
1793          * @param string $fullCont Resolved container name
1794          * @param string $dir Resolved directory relative to container
1795          * @param array $params
1796          */
1797         public function __construct( SwiftFileBackend $backend, $fullCont, $dir, array $params ) {
1798                 $this->backend = $backend;
1799                 $this->container = $fullCont;
1800                 $this->dir = $dir;
1801                 if ( substr( $this->dir, -1 ) === '/' ) {
1802                         $this->dir = substr( $this->dir, 0, -1 ); // remove trailing slash
1803                 }
1804                 if ( $this->dir == '' ) { // whole container
1805                         $this->suffixStart = 0;
1806                 } else { // dir within container
1807                         $this->suffixStart = strlen( $this->dir ) + 1; // size of "path/to/dir/"
1808                 }
1809                 $this->params = $params;
1810         }
1811
1812         /**
1813          * @see Iterator::key()
1814          * @return int
1815          */
1816         public function key() {
1817                 return $this->pos;
1818         }
1819
1820         /**
1821          * @see Iterator::next()
1822          */
1823         public function next() {
1824                 // Advance to the next file in the page
1825                 next( $this->bufferIter );
1826                 ++$this->pos;
1827                 // Check if there are no files left in this page and
1828                 // advance to the next page if this page was not empty.
1829                 if ( !$this->valid() && count( $this->bufferIter ) ) {
1830                         $this->bufferIter = $this->pageFromList(
1831                                 $this->container, $this->dir, $this->bufferAfter, self::PAGE_SIZE, $this->params
1832                         ); // updates $this->bufferAfter
1833                 }
1834         }
1835
1836         /**
1837          * @see Iterator::rewind()
1838          */
1839         public function rewind() {
1840                 $this->pos = 0;
1841                 $this->bufferAfter = null;
1842                 $this->bufferIter = $this->pageFromList(
1843                         $this->container, $this->dir, $this->bufferAfter, self::PAGE_SIZE, $this->params
1844                 ); // updates $this->bufferAfter
1845         }
1846
1847         /**
1848          * @see Iterator::valid()
1849          * @return bool
1850          */
1851         public function valid() {
1852                 if ( $this->bufferIter === null ) {
1853                         return false; // some failure?
1854                 } else {
1855                         return ( current( $this->bufferIter ) !== false ); // no paths can have this value
1856                 }
1857         }
1858
1859         /**
1860          * Get the given list portion (page)
1861          *
1862          * @param string $container Resolved container name
1863          * @param string $dir Resolved path relative to container
1864          * @param string $after
1865          * @param int $limit
1866          * @param array $params
1867          * @return Traversable|array
1868          */
1869         abstract protected function pageFromList( $container, $dir, &$after, $limit, array $params );
1870 }
1871
1872 /**
1873  * Iterator for listing directories
1874  */
1875 class SwiftFileBackendDirList extends SwiftFileBackendList {
1876         /**
1877          * @see Iterator::current()
1878          * @return string|bool String (relative path) or false
1879          */
1880         public function current() {
1881                 return substr( current( $this->bufferIter ), $this->suffixStart, -1 );
1882         }
1883
1884         protected function pageFromList( $container, $dir, &$after, $limit, array $params ) {
1885                 return $this->backend->getDirListPageInternal( $container, $dir, $after, $limit, $params );
1886         }
1887 }
1888
1889 /**
1890  * Iterator for listing regular files
1891  */
1892 class SwiftFileBackendFileList extends SwiftFileBackendList {
1893         /**
1894          * @see Iterator::current()
1895          * @return string|bool String (relative path) or false
1896          */
1897         public function current() {
1898                 list( $path, $stat ) = current( $this->bufferIter );
1899                 $relPath = substr( $path, $this->suffixStart );
1900                 if ( is_array( $stat ) ) {
1901                         $storageDir = rtrim( $this->params['dir'], '/' );
1902                         $this->backend->loadListingStatInternal( "$storageDir/$relPath", $stat );
1903                 }
1904
1905                 return $relPath;
1906         }
1907
1908         protected function pageFromList( $container, $dir, &$after, $limit, array $params ) {
1909                 return $this->backend->getFileListPageInternal( $container, $dir, $after, $limit, $params );
1910         }
1911 }