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