includes/filebackend/SwiftFileBackend.php

   1 <?php
   2 /**
   3  * OpenStack Swift based file backend.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup FileBackend
  22  * @author Russ Nelson
  23  * @author Aaron Schulz
  24  */
  25
  26 /**
  27  * @brief Class for an OpenStack Swift (or Ceph RGW) based file backend.
  28  *
  29  * Status messages should avoid mentioning the Swift account name.
  30  * Likewise, error suppression should be used to avoid path disclosure.
  31  *
  32  * @ingroup FileBackend
  33  * @since 1.19
  34  */
  35 class SwiftFileBackend extends FileBackendStore {
  36         /** @var MultiHttpClient */
  37         protected $http;
  38
  39         /** @var int TTL in seconds */
  40         protected $authTTL;
  41
  42         /** @var string Authentication base URL (without version) */
  43         protected $swiftAuthUrl;
  44
  45         /** @var string Swift user (account:user) to authenticate as */
  46         protected $swiftUser;
  47
  48         /** @var string Secret key for user */
  49         protected $swiftKey;
  50
  51         /** @var string Shared secret value for making temp URLs */
  52         protected $swiftTempUrlKey;
  53
  54         /** @var string S3 access key (RADOS Gateway) */
  55         protected $rgwS3AccessKey;
  56
  57         /** @var string S3 authentication key (RADOS Gateway) */
  58         protected $rgwS3SecretKey;
  59
  60         /** @var BagOStuff */
  61         protected $srvCache;
  62
  63         /** @var ProcessCacheLRU Container stat cache */
  64         protected $containerStatCache;
  65
  66         /** @var array */
  67         protected $authCreds;
  68
  69         /** @var int UNIX timestamp */
  70         protected $authSessionTimestamp = 0;
  71
  72         /** @var int UNIX timestamp */
  73         protected $authErrorTimestamp = null;
  74
  75         /** @var bool Whether the server is an Ceph RGW */
  76         protected $isRGW = false;
  77
  78         /**
  79          * @see FileBackendStore::__construct()
  80          * Additional $config params include:
  81          *   - swiftAuthUrl       : Swift authentication server URL
  82          *   - swiftUser          : Swift user used by MediaWiki (account:username)
  83          *   - swiftKey           : Swift authentication key for the above user
  84          *   - swiftAuthTTL       : Swift authentication TTL (seconds)
  85          *   - swiftTempUrlKey    : Swift "X-Account-Meta-Temp-URL-Key" value on the account.
  86          *                          Do not set this until it has been set in the backend.
  87          *   - shardViaHashLevels : Map of container names to sharding config with:
  88          *                             - base   : base of hash characters, 16 or 36
  89          *                             - levels : the number of hash levels (and digits)
  90          *                             - repeat : hash subdirectories are prefixed with all the
  91          *                                        parent hash directory names (e.g. "a/ab/abc")
  92          *   - cacheAuthInfo      : Whether to cache authentication tokens in APC, XCache, ect.
  93          *                          If those are not available, then the main cache will be used.
  94          *                          This is probably insecure in shared hosting environments.
  95          *   - rgwS3AccessKey     : Rados Gateway S3 "access key" value on the account.
  96          *                          Do not set this until it has been set in the backend.
  97          *                          This is used for generating expiring pre-authenticated URLs.
  98          *                          Only use this when using rgw and to work around
  99          *                          http://tracker.newdream.net/issues/3454.
 100          *   - rgwS3SecretKey     : Rados Gateway S3 "secret key" value on the account.
 101          *                          Do not set this until it has been set in the backend.
 102          *                          This is used for generating expiring pre-authenticated URLs.
 103          *                          Only use this when using rgw and to work around
 104          *                          http://tracker.newdream.net/issues/3454.
 105          */
 106         public function __construct( array $config ) {
 107                 parent::__construct( $config );
 108                 // Required settings
 109                 $this->swiftAuthUrl = $config['swiftAuthUrl'];
 110                 $this->swiftUser = $config['swiftUser'];
 111                 $this->swiftKey = $config['swiftKey'];
 112                 // Optional settings
 113                 $this->authTTL = isset( $config['swiftAuthTTL'] )
 114                         ? $config['swiftAuthTTL']
 115                         : 15 * 60; // some sane number
 116                 $this->swiftTempUrlKey = isset( $config['swiftTempUrlKey'] )
 117                         ? $config['swiftTempUrlKey']
 118                         : '';
 119                 $this->shardViaHashLevels = isset( $config['shardViaHashLevels'] )
 120                         ? $config['shardViaHashLevels']
 121                         : '';
 122                 $this->rgwS3AccessKey = isset( $config['rgwS3AccessKey'] )
 123                         ? $config['rgwS3AccessKey']
 124                         : '';
 125                 $this->rgwS3SecretKey = isset( $config['rgwS3SecretKey'] )
 126                         ? $config['rgwS3SecretKey']
 127                         : '';
 128                 // HTTP helper client
 129                 $this->http = new MultiHttpClient( array() );
 130                 // Cache container information to mask latency
 131                 if ( isset( $config['wanCache'] ) && $config['wanCache'] instanceof WANObjectCache ) {
 132                         $this->memCache = $config['wanCache'];
 133                 }
 134                 // Process cache for container info
 135                 $this->containerStatCache = new ProcessCacheLRU( 300 );
 136                 // Cache auth token information to avoid RTTs
 137                 if ( !empty( $config['cacheAuthInfo'] ) ) {
 138                         if ( PHP_SAPI === 'cli' ) {
 139                                 $this->srvCache = wfGetMainCache(); // preferrably memcached
 140                         } else {
 141                                 // look for APC, XCache, WinCache, ect...
 142                                 $this->srvCache = ObjectCache::newAccelerator( CACHE_NONE );
 143                         }
 144                 } else {
 145                         $this->srvCache = new EmptyBagOStuff();
 146                 }
 147         }
 148
 149         public function getFeatures() {
 150                 return ( FileBackend::ATTR_UNICODE_PATHS |
 151                         FileBackend::ATTR_HEADERS | FileBackend::ATTR_METADATA );
 152         }
 153
 154         protected function resolveContainerPath( $container, $relStoragePath ) {
 155                 if ( !mb_check_encoding( $relStoragePath, 'UTF-8' ) ) { // mb_string required by CF
 156                         return null; // not UTF-8, makes it hard to use CF and the swift HTTP API
 157                 } elseif ( strlen( urlencode( $relStoragePath ) ) > 1024 ) {
 158                         return null; // too long for Swift
 159                 }
 160
 161                 return $relStoragePath;
 162         }
 163
 164         public function isPathUsableInternal( $storagePath ) {
 165                 list( $container, $rel ) = $this->resolveStoragePathReal( $storagePath );
 166                 if ( $rel === null ) {
 167                         return false; // invalid
 168                 }
 169
 170                 return is_array( $this->getContainerStat( $container ) );
 171         }
 172
 173         /**
 174          * Sanitize and filter the custom headers from a $params array.
 175          * Only allows certain "standard" Content- and X-Content- headers.
 176          *
 177          * @param array $params
 178          * @return array Sanitized value of 'headers' field in $params
 179          */
 180         protected function sanitizeHdrs( array $params ) {
 181                 return isset( $params['headers'] )
 182                         ? $this->getCustomHeaders( $params['headers'] )
 183                         : array();
 184
 185         }
 186
 187         /**
 188          * @param array $rawHeaders
 189          * @return array Custom non-metadata HTTP headers
 190          */
 191         protected function getCustomHeaders( array $rawHeaders ) {
 192                 $headers = array();
 193
 194                 // Normalize casing, and strip out illegal headers
 195                 foreach ( $rawHeaders as $name => $value ) {
 196                         $name = strtolower( $name );
 197                         if ( preg_match( '/^content-(type|length)$/', $name ) ) {
 198                                 continue; // blacklisted
 199                         } elseif ( preg_match( '/^(x-)?content-/', $name ) ) {
 200                                 $headers[$name] = $value; // allowed
 201                         } elseif ( preg_match( '/^content-(disposition)/', $name ) ) {
 202                                 $headers[$name] = $value; // allowed
 203                         }
 204                 }
 205                 // By default, Swift has annoyingly low maximum header value limits
 206                 if ( isset( $headers['content-disposition'] ) ) {
 207                         $disposition = '';
 208                         // @note: assume FileBackend::makeContentDisposition() already used
 209                         foreach ( explode( ';', $headers['content-disposition'] ) as $part ) {
 210                                 $part = trim( $part );
 211                                 $new = ( $disposition === '' ) ? $part : "{$disposition};{$part}";
 212                                 if ( strlen( $new ) <= 255 ) {
 213                                         $disposition = $new;
 214                                 } else {
 215                                         break; // too long; sigh
 216                                 }
 217                         }
 218                         $headers['content-disposition'] = $disposition;
 219                 }
 220
 221                 return $headers;
 222         }
 223
 224         /**
 225          * @param array $rawHeaders
 226          * @return array Custom metadata headers
 227          */
 228         protected function getMetadataHeaders( array $rawHeaders ) {
 229                 $headers = array();
 230                 foreach ( $rawHeaders as $name => $value ) {
 231                         $name = strtolower( $name );
 232                         if ( strpos( $name, 'x-object-meta-' ) === 0 ) {
 233                                 $headers[$name] = $value;
 234                         }
 235                 }
 236
 237                 return $headers;
 238         }
 239
 240         /**
 241          * @param array $rawHeaders
 242          * @return array Custom metadata headers with prefix removed
 243          */
 244         protected function getMetadata( array $rawHeaders ) {
 245                 $metadata = array();
 246                 foreach ( $this->getMetadataHeaders( $rawHeaders ) as $name => $value ) {
 247                         $metadata[substr( $name, strlen( 'x-object-meta-' ) )] = $value;
 248                 }
 249
 250                 return $metadata;
 251         }
 252
 253         protected function doCreateInternal( array $params ) {
 254                 $status = Status::newGood();
 255
 256                 list( $dstCont, $dstRel ) = $this->resolveStoragePathReal( $params['dst'] );
 257                 if ( $dstRel === null ) {
 258                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 259
 260                         return $status;
 261                 }
 262
 263                 $sha1Hash = wfBaseConvert( sha1( $params['content'] ), 16, 36, 31 );
 264                 $contentType = $this->getContentType( $params['dst'], $params['content'], null );
 265
 266                 $reqs = array( array(
 267                         'method' => 'PUT',
 268                         'url' => array( $dstCont, $dstRel ),
 269                         'headers' => array(
 270                                 'content-length' => strlen( $params['content'] ),
 271                                 'etag' => md5( $params['content'] ),
 272                                 'content-type' => $contentType,
 273                                 'x-object-meta-sha1base36' => $sha1Hash
 274                         ) + $this->sanitizeHdrs( $params ),
 275                         'body' => $params['content']
 276                 ) );
 277
 278                 $that = $this;
 279                 $method = __METHOD__;
 280                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 281                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 282                         if ( $rcode === 201 ) {
 283                                 // good
 284                         } elseif ( $rcode === 412 ) {
 285                                 $status->fatal( 'backend-fail-contenttype', $params['dst'] );
 286                         } else {
 287                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 288                         }
 289                 };
 290
 291                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 292                 if ( !empty( $params['async'] ) ) { // deferred
 293                         $status->value = $opHandle;
 294                 } else { // actually write the object in Swift
 295                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 296                 }
 297
 298                 return $status;
 299         }
 300
 301         protected function doStoreInternal( array $params ) {
 302                 $status = Status::newGood();
 303
 304                 list( $dstCont, $dstRel ) = $this->resolveStoragePathReal( $params['dst'] );
 305                 if ( $dstRel === null ) {
 306                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 307
 308                         return $status;
 309                 }
 310
 311                 MediaWiki\suppressWarnings();
 312                 $sha1Hash = sha1_file( $params['src'] );
 313                 MediaWiki\restoreWarnings();
 314                 if ( $sha1Hash === false ) { // source doesn't exist?
 315                         $status->fatal( 'backend-fail-store', $params['src'], $params['dst'] );
 316
 317                         return $status;
 318                 }
 319                 $sha1Hash = wfBaseConvert( $sha1Hash, 16, 36, 31 );
 320                 $contentType = $this->getContentType( $params['dst'], null, $params['src'] );
 321
 322                 $handle = fopen( $params['src'], 'rb' );
 323                 if ( $handle === false ) { // source doesn't exist?
 324                         $status->fatal( 'backend-fail-store', $params['src'], $params['dst'] );
 325
 326                         return $status;
 327                 }
 328
 329                 $reqs = array( array(
 330                         'method' => 'PUT',
 331                         'url' => array( $dstCont, $dstRel ),
 332                         'headers' => array(
 333                                 'content-length' => filesize( $params['src'] ),
 334                                 'etag' => md5_file( $params['src'] ),
 335                                 'content-type' => $contentType,
 336                                 'x-object-meta-sha1base36' => $sha1Hash
 337                         ) + $this->sanitizeHdrs( $params ),
 338                         'body' => $handle // resource
 339                 ) );
 340
 341                 $that = $this;
 342                 $method = __METHOD__;
 343                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 344                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 345                         if ( $rcode === 201 ) {
 346                                 // good
 347                         } elseif ( $rcode === 412 ) {
 348                                 $status->fatal( 'backend-fail-contenttype', $params['dst'] );
 349                         } else {
 350                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 351                         }
 352                 };
 353
 354                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 355                 if ( !empty( $params['async'] ) ) { // deferred
 356                         $status->value = $opHandle;
 357                 } else { // actually write the object in Swift
 358                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 359                 }
 360
 361                 return $status;
 362         }
 363
 364         protected function doCopyInternal( array $params ) {
 365                 $status = Status::newGood();
 366
 367                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
 368                 if ( $srcRel === null ) {
 369                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 370
 371                         return $status;
 372                 }
 373
 374                 list( $dstCont, $dstRel ) = $this->resolveStoragePathReal( $params['dst'] );
 375                 if ( $dstRel === null ) {
 376                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 377
 378                         return $status;
 379                 }
 380
 381                 $reqs = array( array(
 382                         'method' => 'PUT',
 383                         'url' => array( $dstCont, $dstRel ),
 384                         'headers' => array(
 385                                 'x-copy-from' => '/' . rawurlencode( $srcCont ) .
 386                                         '/' . str_replace( "%2F", "/", rawurlencode( $srcRel ) )
 387                         ) + $this->sanitizeHdrs( $params ), // extra headers merged into object
 388                 ) );
 389
 390                 $that = $this;
 391                 $method = __METHOD__;
 392                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 393                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 394                         if ( $rcode === 201 ) {
 395                                 // good
 396                         } elseif ( $rcode === 404 ) {
 397                                 $status->fatal( 'backend-fail-copy', $params['src'], $params['dst'] );
 398                         } else {
 399                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 400                         }
 401                 };
 402
 403                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 404                 if ( !empty( $params['async'] ) ) { // deferred
 405                         $status->value = $opHandle;
 406                 } else { // actually write the object in Swift
 407                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 408                 }
 409
 410                 return $status;
 411         }
 412
 413         protected function doMoveInternal( array $params ) {
 414                 $status = Status::newGood();
 415
 416                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
 417                 if ( $srcRel === null ) {
 418                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 419
 420                         return $status;
 421                 }
 422
 423                 list( $dstCont, $dstRel ) = $this->resolveStoragePathReal( $params['dst'] );
 424                 if ( $dstRel === null ) {
 425                         $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
 426
 427                         return $status;
 428                 }
 429
 430                 $reqs = array(
 431                         array(
 432                                 'method' => 'PUT',
 433                                 'url' => array( $dstCont, $dstRel ),
 434                                 'headers' => array(
 435                                         'x-copy-from' => '/' . rawurlencode( $srcCont ) .
 436                                                 '/' . str_replace( "%2F", "/", rawurlencode( $srcRel ) )
 437                                 ) + $this->sanitizeHdrs( $params ) // extra headers merged into object
 438                         )
 439                 );
 440                 if ( "{$srcCont}/{$srcRel}" !== "{$dstCont}/{$dstRel}" ) {
 441                         $reqs[] = array(
 442                                 'method' => 'DELETE',
 443                                 'url' => array( $srcCont, $srcRel ),
 444                                 'headers' => array()
 445                         );
 446                 }
 447
 448                 $that = $this;
 449                 $method = __METHOD__;
 450                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 451                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 452                         if ( $request['method'] === 'PUT' && $rcode === 201 ) {
 453                                 // good
 454                         } elseif ( $request['method'] === 'DELETE' && $rcode === 204 ) {
 455                                 // good
 456                         } elseif ( $rcode === 404 ) {
 457                                 $status->fatal( 'backend-fail-move', $params['src'], $params['dst'] );
 458                         } else {
 459                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 460                         }
 461                 };
 462
 463                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 464                 if ( !empty( $params['async'] ) ) { // deferred
 465                         $status->value = $opHandle;
 466                 } else { // actually move the object in Swift
 467                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 468                 }
 469
 470                 return $status;
 471         }
 472
 473         protected function doDeleteInternal( array $params ) {
 474                 $status = Status::newGood();
 475
 476                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
 477                 if ( $srcRel === null ) {
 478                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 479
 480                         return $status;
 481                 }
 482
 483                 $reqs = array( array(
 484                         'method' => 'DELETE',
 485                         'url' => array( $srcCont, $srcRel ),
 486                         'headers' => array()
 487                 ) );
 488
 489                 $that = $this;
 490                 $method = __METHOD__;
 491                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 492                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 493                         if ( $rcode === 204 ) {
 494                                 // good
 495                         } elseif ( $rcode === 404 ) {
 496                                 if ( empty( $params['ignoreMissingSource'] ) ) {
 497                                         $status->fatal( 'backend-fail-delete', $params['src'] );
 498                                 }
 499                         } else {
 500                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 501                         }
 502                 };
 503
 504                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 505                 if ( !empty( $params['async'] ) ) { // deferred
 506                         $status->value = $opHandle;
 507                 } else { // actually delete the object in Swift
 508                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 509                 }
 510
 511                 return $status;
 512         }
 513
 514         protected function doDescribeInternal( array $params ) {
 515                 $status = Status::newGood();
 516
 517                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
 518                 if ( $srcRel === null ) {
 519                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
 520
 521                         return $status;
 522                 }
 523
 524                 // Fetch the old object headers/metadata...this should be in stat cache by now
 525                 $stat = $this->getFileStat( array( 'src' => $params['src'], 'latest' => 1 ) );
 526                 if ( $stat && !isset( $stat['xattr'] ) ) { // older cache entry
 527                         $stat = $this->doGetFileStat( array( 'src' => $params['src'], 'latest' => 1 ) );
 528                 }
 529                 if ( !$stat ) {
 530                         $status->fatal( 'backend-fail-describe', $params['src'] );
 531
 532                         return $status;
 533                 }
 534
 535                 // POST clears prior headers, so we need to merge the changes in to the old ones
 536                 $metaHdrs = array();
 537                 foreach ( $stat['xattr']['metadata'] as $name => $value ) {
 538                         $metaHdrs["x-object-meta-$name"] = $value;
 539                 }
 540                 $customHdrs = $this->sanitizeHdrs( $params ) + $stat['xattr']['headers'];
 541
 542                 $reqs = array( array(
 543                         'method' => 'POST',
 544                         'url' => array( $srcCont, $srcRel ),
 545                         'headers' => $metaHdrs + $customHdrs
 546                 ) );
 547
 548                 $that = $this;
 549                 $method = __METHOD__;
 550                 $handler = function ( array $request, Status $status ) use ( $that, $method, $params ) {
 551                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $request['response'];
 552                         if ( $rcode === 202 ) {
 553                                 // good
 554                         } elseif ( $rcode === 404 ) {
 555                                 $status->fatal( 'backend-fail-describe', $params['src'] );
 556                         } else {
 557                                 $that->onError( $status, $method, $params, $rerr, $rcode, $rdesc );
 558                         }
 559                 };
 560
 561                 $opHandle = new SwiftFileOpHandle( $this, $handler, $reqs );
 562                 if ( !empty( $params['async'] ) ) { // deferred
 563                         $status->value = $opHandle;
 564                 } else { // actually change the object in Swift
 565                         $status->merge( current( $this->doExecuteOpHandlesInternal( array( $opHandle ) ) ) );
 566                 }
 567
 568                 return $status;
 569         }
 570
 571         protected function doPrepareInternal( $fullCont, $dir, array $params ) {
 572                 $status = Status::newGood();
 573
 574                 // (a) Check if container already exists
 575                 $stat = $this->getContainerStat( $fullCont );
 576                 if ( is_array( $stat ) ) {
 577                         return $status; // already there
 578                 } elseif ( $stat === null ) {
 579                         $status->fatal( 'backend-fail-internal', $this->name );
 580                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': cannot get container stat' );
 581
 582                         return $status;
 583                 }
 584
 585                 // (b) Create container as needed with proper ACLs
 586                 if ( $stat === false ) {
 587                         $params['op'] = 'prepare';
 588                         $status->merge( $this->createContainer( $fullCont, $params ) );
 589                 }
 590
 591                 return $status;
 592         }
 593
 594         protected function doSecureInternal( $fullCont, $dir, array $params ) {
 595                 $status = Status::newGood();
 596                 if ( empty( $params['noAccess'] ) ) {
 597                         return $status; // nothing to do
 598                 }
 599
 600                 $stat = $this->getContainerStat( $fullCont );
 601                 if ( is_array( $stat ) ) {
 602                         // Make container private to end-users...
 603                         $status->merge( $this->setContainerAccess(
 604                                 $fullCont,
 605                                 array( $this->swiftUser ), // read
 606                                 array( $this->swiftUser ) // write
 607                         ) );
 608                 } elseif ( $stat === false ) {
 609                         $status->fatal( 'backend-fail-usable', $params['dir'] );
 610                 } else {
 611                         $status->fatal( 'backend-fail-internal', $this->name );
 612                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': cannot get container stat' );
 613                 }
 614
 615                 return $status;
 616         }
 617
 618         protected function doPublishInternal( $fullCont, $dir, array $params ) {
 619                 $status = Status::newGood();
 620
 621                 $stat = $this->getContainerStat( $fullCont );
 622                 if ( is_array( $stat ) ) {
 623                         // Make container public to end-users...
 624                         $status->merge( $this->setContainerAccess(
 625                                 $fullCont,
 626                                 array( $this->swiftUser, '.r:*' ), // read
 627                                 array( $this->swiftUser ) // write
 628                         ) );
 629                 } elseif ( $stat === false ) {
 630                         $status->fatal( 'backend-fail-usable', $params['dir'] );
 631                 } else {
 632                         $status->fatal( 'backend-fail-internal', $this->name );
 633                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': cannot get container stat' );
 634                 }
 635
 636                 return $status;
 637         }
 638
 639         protected function doCleanInternal( $fullCont, $dir, array $params ) {
 640                 $status = Status::newGood();
 641
 642                 // Only containers themselves can be removed, all else is virtual
 643                 if ( $dir != '' ) {
 644                         return $status; // nothing to do
 645                 }
 646
 647                 // (a) Check the container
 648                 $stat = $this->getContainerStat( $fullCont, true );
 649                 if ( $stat === false ) {
 650                         return $status; // ok, nothing to do
 651                 } elseif ( !is_array( $stat ) ) {
 652                         $status->fatal( 'backend-fail-internal', $this->name );
 653                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': cannot get container stat' );
 654
 655                         return $status;
 656                 }
 657
 658                 // (b) Delete the container if empty
 659                 if ( $stat['count'] == 0 ) {
 660                         $params['op'] = 'clean';
 661                         $status->merge( $this->deleteContainer( $fullCont, $params ) );
 662                 }
 663
 664                 return $status;
 665         }
 666
 667         protected function doGetFileStat( array $params ) {
 668                 $params = array( 'srcs' => array( $params['src'] ), 'concurrency' => 1 ) + $params;
 669                 unset( $params['src'] );
 670                 $stats = $this->doGetFileStatMulti( $params );
 671
 672                 return reset( $stats );
 673         }
 674
 675         /**
 676          * Convert dates like "Tue, 03 Jan 2012 22:01:04 GMT"/"2013-05-11T07:37:27.678360Z".
 677          * Dates might also come in like "2013-05-11T07:37:27.678360" from Swift listings,
 678          * missing the timezone suffix (though Ceph RGW does not appear to have this bug).
 679          *
 680          * @param string $ts
 681          * @param int $format Output format (TS_* constant)
 682          * @return string
 683          * @throws FileBackendError
 684          */
 685         protected function convertSwiftDate( $ts, $format = TS_MW ) {
 686                 try {
 687                         $timestamp = new MWTimestamp( $ts );
 688
 689                         return $timestamp->getTimestamp( $format );
 690                 } catch ( Exception $e ) {
 691                         throw new FileBackendError( $e->getMessage() );
 692                 }
 693         }
 694
 695         /**
 696          * Fill in any missing object metadata and save it to Swift
 697          *
 698          * @param array $objHdrs Object response headers
 699          * @param string $path Storage path to object
 700          * @return array New headers
 701          */
 702         protected function addMissingMetadata( array $objHdrs, $path ) {
 703                 if ( isset( $objHdrs['x-object-meta-sha1base36'] ) ) {
 704                         return $objHdrs; // nothing to do
 705                 }
 706
 707                 /** @noinspection PhpUnusedLocalVariableInspection */
 708                 $ps = Profiler::instance()->scopedProfileIn( __METHOD__ . "-{$this->name}" );
 709                 wfDebugLog( 'SwiftBackend', __METHOD__ . ": $path was not stored with SHA-1 metadata." );
 710
 711                 $objHdrs['x-object-meta-sha1base36'] = false;
 712
 713                 $auth = $this->getAuthentication();
 714                 if ( !$auth ) {
 715                         return $objHdrs; // failed
 716                 }
 717
 718                 $status = Status::newGood();
 719                 /** @noinspection PhpUnusedLocalVariableInspection */
 720                 $scopeLockS = $this->getScopedFileLocks( array( $path ), LockManager::LOCK_UW, $status );
 721                 if ( $status->isOK() ) {
 722                         $tmpFile = $this->getLocalCopy( array( 'src' => $path, 'latest' => 1 ) );
 723                         if ( $tmpFile ) {
 724                                 $hash = $tmpFile->getSha1Base36();
 725                                 if ( $hash !== false ) {
 726                                         $objHdrs['x-object-meta-sha1base36'] = $hash;
 727                                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
 728                                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
 729                                                 'method' => 'POST',
 730                                                 'url' => $this->storageUrl( $auth, $srcCont, $srcRel ),
 731                                                 'headers' => $this->authTokenHeaders( $auth ) + $objHdrs
 732                                         ) );
 733                                         if ( $rcode >= 200 && $rcode <= 299 ) {
 734                                                 $this->deleteFileCache( $path );
 735
 736                                                 return $objHdrs; // success
 737                                         }
 738                                 }
 739                         }
 740                 }
 741
 742                 wfDebugLog( 'SwiftBackend', __METHOD__ . ": unable to set SHA-1 metadata for $path" );
 743
 744                 return $objHdrs; // failed
 745         }
 746
 747         protected function doGetFileContentsMulti( array $params ) {
 748                 $contents = array();
 749
 750                 $auth = $this->getAuthentication();
 751
 752                 $ep = array_diff_key( $params, array( 'srcs' => 1 ) ); // for error logging
 753                 // Blindly create tmp files and stream to them, catching any exception if the file does
 754                 // not exist. Doing stats here is useless and will loop infinitely in addMissingMetadata().
 755                 $reqs = array(); // (path => op)
 756
 757                 foreach ( $params['srcs'] as $path ) { // each path in this concurrent batch
 758                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
 759                         if ( $srcRel === null || !$auth ) {
 760                                 $contents[$path] = false;
 761                                 continue;
 762                         }
 763                         // Create a new temporary memory file...
 764                         $handle = fopen( 'php://temp', 'wb' );
 765                         if ( $handle ) {
 766                                 $reqs[$path] = array(
 767                                         'method'  => 'GET',
 768                                         'url'     => $this->storageUrl( $auth, $srcCont, $srcRel ),
 769                                         'headers' => $this->authTokenHeaders( $auth )
 770                                                 + $this->headersFromParams( $params ),
 771                                         'stream'  => $handle,
 772                                 );
 773                         }
 774                         $contents[$path] = false;
 775                 }
 776
 777                 $opts = array( 'maxConnsPerHost' => $params['concurrency'] );
 778                 $reqs = $this->http->runMulti( $reqs, $opts );
 779                 foreach ( $reqs as $path => $op ) {
 780                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $op['response'];
 781                         if ( $rcode >= 200 && $rcode <= 299 ) {
 782                                 rewind( $op['stream'] ); // start from the beginning
 783                                 $contents[$path] = stream_get_contents( $op['stream'] );
 784                         } elseif ( $rcode === 404 ) {
 785                                 $contents[$path] = false;
 786                         } else {
 787                                 $this->onError( null, __METHOD__,
 788                                         array( 'src' => $path ) + $ep, $rerr, $rcode, $rdesc );
 789                         }
 790                         fclose( $op['stream'] ); // close open handle
 791                 }
 792
 793                 return $contents;
 794         }
 795
 796         protected function doDirectoryExists( $fullCont, $dir, array $params ) {
 797                 $prefix = ( $dir == '' ) ? null : "{$dir}/";
 798                 $status = $this->objectListing( $fullCont, 'names', 1, null, $prefix );
 799                 if ( $status->isOk() ) {
 800                         return ( count( $status->value ) ) > 0;
 801                 }
 802
 803                 return null; // error
 804         }
 805
 806         /**
 807          * @see FileBackendStore::getDirectoryListInternal()
 808          * @param string $fullCont
 809          * @param string $dir
 810          * @param array $params
 811          * @return SwiftFileBackendDirList
 812          */
 813         public function getDirectoryListInternal( $fullCont, $dir, array $params ) {
 814                 return new SwiftFileBackendDirList( $this, $fullCont, $dir, $params );
 815         }
 816
 817         /**
 818          * @see FileBackendStore::getFileListInternal()
 819          * @param string $fullCont
 820          * @param string $dir
 821          * @param array $params
 822          * @return SwiftFileBackendFileList
 823          */
 824         public function getFileListInternal( $fullCont, $dir, array $params ) {
 825                 return new SwiftFileBackendFileList( $this, $fullCont, $dir, $params );
 826         }
 827
 828         /**
 829          * Do not call this function outside of SwiftFileBackendFileList
 830          *
 831          * @param string $fullCont Resolved container name
 832          * @param string $dir Resolved storage directory with no trailing slash
 833          * @param string|null $after Resolved container relative path to list items after
 834          * @param int $limit Max number of items to list
 835          * @param array $params Parameters for getDirectoryList()
 836          * @return array List of container relative resolved paths of directories directly under $dir
 837          * @throws FileBackendError
 838          */
 839         public function getDirListPageInternal( $fullCont, $dir, &$after, $limit, array $params ) {
 840                 $dirs = array();
 841                 if ( $after === INF ) {
 842                         return $dirs; // nothing more
 843                 }
 844
 845                 $ps = Profiler::instance()->scopedProfileIn( __METHOD__ . "-{$this->name}" );
 846
 847                 $prefix = ( $dir == '' ) ? null : "{$dir}/";
 848                 // Non-recursive: only list dirs right under $dir
 849                 if ( !empty( $params['topOnly'] ) ) {
 850                         $status = $this->objectListing( $fullCont, 'names', $limit, $after, $prefix, '/' );
 851                         if ( !$status->isOk() ) {
 852                                 return $dirs; // error
 853                         }
 854                         $objects = $status->value;
 855                         foreach ( $objects as $object ) { // files and directories
 856                                 if ( substr( $object, -1 ) === '/' ) {
 857                                         $dirs[] = $object; // directories end in '/'
 858                                 }
 859                         }
 860                 } else {
 861                         // Recursive: list all dirs under $dir and its subdirs
 862                         $getParentDir = function ( $path ) {
 863                                 return ( strpos( $path, '/' ) !== false ) ? dirname( $path ) : false;
 864                         };
 865
 866                         // Get directory from last item of prior page
 867                         $lastDir = $getParentDir( $after ); // must be first page
 868                         $status = $this->objectListing( $fullCont, 'names', $limit, $after, $prefix );
 869
 870                         if ( !$status->isOk() ) {
 871                                 return $dirs; // error
 872                         }
 873
 874                         $objects = $status->value;
 875
 876                         foreach ( $objects as $object ) { // files
 877                                 $objectDir = $getParentDir( $object ); // directory of object
 878
 879                                 if ( $objectDir !== false && $objectDir !== $dir ) {
 880                                         // Swift stores paths in UTF-8, using binary sorting.
 881                                         // See function "create_container_table" in common/db.py.
 882                                         // If a directory is not "greater" than the last one,
 883                                         // then it was already listed by the calling iterator.
 884                                         if ( strcmp( $objectDir, $lastDir ) > 0 ) {
 885                                                 $pDir = $objectDir;
 886                                                 do { // add dir and all its parent dirs
 887                                                         $dirs[] = "{$pDir}/";
 888                                                         $pDir = $getParentDir( $pDir );
 889                                                 } while ( $pDir !== false // sanity
 890                                                         && strcmp( $pDir, $lastDir ) > 0 // not done already
 891                                                         && strlen( $pDir ) > strlen( $dir ) // within $dir
 892                                                 );
 893                                         }
 894                                         $lastDir = $objectDir;
 895                                 }
 896                         }
 897                 }
 898                 // Page on the unfiltered directory listing (what is returned may be filtered)
 899                 if ( count( $objects ) < $limit ) {
 900                         $after = INF; // avoid a second RTT
 901                 } else {
 902                         $after = end( $objects ); // update last item
 903                 }
 904
 905                 return $dirs;
 906         }
 907
 908         /**
 909          * Do not call this function outside of SwiftFileBackendFileList
 910          *
 911          * @param string $fullCont Resolved container name
 912          * @param string $dir Resolved storage directory with no trailing slash
 913          * @param string|null $after Resolved container relative path of file to list items after
 914          * @param int $limit Max number of items to list
 915          * @param array $params Parameters for getDirectoryList()
 916          * @return array List of resolved container relative paths of files under $dir
 917          * @throws FileBackendError
 918          */
 919         public function getFileListPageInternal( $fullCont, $dir, &$after, $limit, array $params ) {
 920                 $files = array(); // list of (path, stat array or null) entries
 921                 if ( $after === INF ) {
 922                         return $files; // nothing more
 923                 }
 924
 925                 $ps = Profiler::instance()->scopedProfileIn( __METHOD__ . "-{$this->name}" );
 926
 927                 $prefix = ( $dir == '' ) ? null : "{$dir}/";
 928                 // $objects will contain a list of unfiltered names or CF_Object items
 929                 // Non-recursive: only list files right under $dir
 930                 if ( !empty( $params['topOnly'] ) ) {
 931                         if ( !empty( $params['adviseStat'] ) ) {
 932                                 $status = $this->objectListing( $fullCont, 'info', $limit, $after, $prefix, '/' );
 933                         } else {
 934                                 $status = $this->objectListing( $fullCont, 'names', $limit, $after, $prefix, '/' );
 935                         }
 936                 } else {
 937                         // Recursive: list all files under $dir and its subdirs
 938                         if ( !empty( $params['adviseStat'] ) ) {
 939                                 $status = $this->objectListing( $fullCont, 'info', $limit, $after, $prefix );
 940                         } else {
 941                                 $status = $this->objectListing( $fullCont, 'names', $limit, $after, $prefix );
 942                         }
 943                 }
 944
 945                 // Reformat this list into a list of (name, stat array or null) entries
 946                 if ( !$status->isOk() ) {
 947                         return $files; // error
 948                 }
 949
 950                 $objects = $status->value;
 951                 $files = $this->buildFileObjectListing( $params, $dir, $objects );
 952
 953                 // Page on the unfiltered object listing (what is returned may be filtered)
 954                 if ( count( $objects ) < $limit ) {
 955                         $after = INF; // avoid a second RTT
 956                 } else {
 957                         $after = end( $objects ); // update last item
 958                         $after = is_object( $after ) ? $after->name : $after;
 959                 }
 960
 961                 return $files;
 962         }
 963
 964         /**
 965          * Build a list of file objects, filtering out any directories
 966          * and extracting any stat info if provided in $objects (for CF_Objects)
 967          *
 968          * @param array $params Parameters for getDirectoryList()
 969          * @param string $dir Resolved container directory path
 970          * @param array $objects List of CF_Object items or object names
 971          * @return array List of (names,stat array or null) entries
 972          */
 973         private function buildFileObjectListing( array $params, $dir, array $objects ) {
 974                 $names = array();
 975                 foreach ( $objects as $object ) {
 976                         if ( is_object( $object ) ) {
 977                                 if ( isset( $object->subdir ) || !isset( $object->name ) ) {
 978                                         continue; // virtual directory entry; ignore
 979                                 }
 980                                 $stat = array(
 981                                         // Convert various random Swift dates to TS_MW
 982                                         'mtime'  => $this->convertSwiftDate( $object->last_modified, TS_MW ),
 983                                         'size'   => (int)$object->bytes,
 984                                         'sha1'   => null,
 985                                         // Note: manifiest ETags are not an MD5 of the file
 986                                         'md5'    => ctype_xdigit( $object->hash ) ? $object->hash : null,
 987                                         'latest' => false // eventually consistent
 988                                 );
 989                                 $names[] = array( $object->name, $stat );
 990                         } elseif ( substr( $object, -1 ) !== '/' ) {
 991                                 // Omit directories, which end in '/' in listings
 992                                 $names[] = array( $object, null );
 993                         }
 994                 }
 995
 996                 return $names;
 997         }
 998
 999         /**
1000          * Do not call this function outside of SwiftFileBackendFileList
1001          *
1002          * @param string $path Storage path
1003          * @param array $val Stat value
1004          */
1005         public function loadListingStatInternal( $path, array $val ) {
1006                 $this->cheapCache->set( $path, 'stat', $val );
1007         }
1008
1009         protected function doGetFileXAttributes( array $params ) {
1010                 $stat = $this->getFileStat( $params );
1011                 if ( $stat ) {
1012                         if ( !isset( $stat['xattr'] ) ) {
1013                                 // Stat entries filled by file listings don't include metadata/headers
1014                                 $this->clearCache( array( $params['src'] ) );
1015                                 $stat = $this->getFileStat( $params );
1016                         }
1017
1018                         return $stat['xattr'];
1019                 } else {
1020                         return false;
1021                 }
1022         }
1023
1024         protected function doGetFileSha1base36( array $params ) {
1025                 $stat = $this->getFileStat( $params );
1026                 if ( $stat ) {
1027                         if ( !isset( $stat['sha1'] ) ) {
1028                                 // Stat entries filled by file listings don't include SHA1
1029                                 $this->clearCache( array( $params['src'] ) );
1030                                 $stat = $this->getFileStat( $params );
1031                         }
1032
1033                         return $stat['sha1'];
1034                 } else {
1035                         return false;
1036                 }
1037         }
1038
1039         protected function doStreamFile( array $params ) {
1040                 $status = Status::newGood();
1041
1042                 list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
1043                 if ( $srcRel === null ) {
1044                         $status->fatal( 'backend-fail-invalidpath', $params['src'] );
1045                 }
1046
1047                 $auth = $this->getAuthentication();
1048                 if ( !$auth || !is_array( $this->getContainerStat( $srcCont ) ) ) {
1049                         $status->fatal( 'backend-fail-stream', $params['src'] );
1050
1051                         return $status;
1052                 }
1053
1054                 $handle = fopen( 'php://output', 'wb' );
1055
1056                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1057                         'method' => 'GET',
1058                         'url' => $this->storageUrl( $auth, $srcCont, $srcRel ),
1059                         'headers' => $this->authTokenHeaders( $auth )
1060                                 + $this->headersFromParams( $params ),
1061                         'stream' => $handle,
1062                 ) );
1063
1064                 if ( $rcode >= 200 && $rcode <= 299 ) {
1065                         // good
1066                 } elseif ( $rcode === 404 ) {
1067                         $status->fatal( 'backend-fail-stream', $params['src'] );
1068                 } else {
1069                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc );
1070                 }
1071
1072                 return $status;
1073         }
1074
1075         protected function doGetLocalCopyMulti( array $params ) {
1076                 $tmpFiles = array();
1077
1078                 $auth = $this->getAuthentication();
1079
1080                 $ep = array_diff_key( $params, array( 'srcs' => 1 ) ); // for error logging
1081                 // Blindly create tmp files and stream to them, catching any exception if the file does
1082                 // not exist. Doing a stat here is useless causes infinite loops in addMissingMetadata().
1083                 $reqs = array(); // (path => op)
1084
1085                 foreach ( $params['srcs'] as $path ) { // each path in this concurrent batch
1086                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
1087                         if ( $srcRel === null || !$auth ) {
1088                                 $tmpFiles[$path] = null;
1089                                 continue;
1090                         }
1091                         // Get source file extension
1092                         $ext = FileBackend::extensionFromPath( $path );
1093                         // Create a new temporary file...
1094                         $tmpFile = TempFSFile::factory( 'localcopy_', $ext );
1095                         if ( $tmpFile ) {
1096                                 $handle = fopen( $tmpFile->getPath(), 'wb' );
1097                                 if ( $handle ) {
1098                                         $reqs[$path] = array(
1099                                                 'method'  => 'GET',
1100                                                 'url'     => $this->storageUrl( $auth, $srcCont, $srcRel ),
1101                                                 'headers' => $this->authTokenHeaders( $auth )
1102                                                         + $this->headersFromParams( $params ),
1103                                                 'stream'  => $handle,
1104                                         );
1105                                 } else {
1106                                         $tmpFile = null;
1107                                 }
1108                         }
1109                         $tmpFiles[$path] = $tmpFile;
1110                 }
1111
1112                 $isLatest = ( $this->isRGW || !empty( $params['latest'] ) );
1113                 $opts = array( 'maxConnsPerHost' => $params['concurrency'] );
1114                 $reqs = $this->http->runMulti( $reqs, $opts );
1115                 foreach ( $reqs as $path => $op ) {
1116                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $op['response'];
1117                         fclose( $op['stream'] ); // close open handle
1118                         if ( $rcode >= 200 && $rcode <= 299 ) {
1119                                 $size = $tmpFiles[$path] ? $tmpFiles[$path]->getSize() : 0;
1120                                 // Double check that the disk is not full/broken
1121                                 if ( $size != $rhdrs['content-length'] ) {
1122                                         $tmpFiles[$path] = null;
1123                                         $rerr = "Got {$size}/{$rhdrs['content-length']} bytes";
1124                                         $this->onError( null, __METHOD__,
1125                                                 array( 'src' => $path ) + $ep, $rerr, $rcode, $rdesc );
1126                                 }
1127                                 // Set the file stat process cache in passing
1128                                 $stat = $this->getStatFromHeaders( $rhdrs );
1129                                 $stat['latest'] = $isLatest;
1130                                 $this->cheapCache->set( $path, 'stat', $stat );
1131                         } elseif ( $rcode === 404 ) {
1132                                 $tmpFiles[$path] = false;
1133                         } else {
1134                                 $tmpFiles[$path] = null;
1135                                 $this->onError( null, __METHOD__,
1136                                         array( 'src' => $path ) + $ep, $rerr, $rcode, $rdesc );
1137                         }
1138                 }
1139
1140                 return $tmpFiles;
1141         }
1142
1143         public function getFileHttpUrl( array $params ) {
1144                 if ( $this->swiftTempUrlKey != '' ||
1145                         ( $this->rgwS3AccessKey != '' && $this->rgwS3SecretKey != '' )
1146                 ) {
1147                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
1148                         if ( $srcRel === null ) {
1149                                 return null; // invalid path
1150                         }
1151
1152                         $auth = $this->getAuthentication();
1153                         if ( !$auth ) {
1154                                 return null;
1155                         }
1156
1157                         $ttl = isset( $params['ttl'] ) ? $params['ttl'] : 86400;
1158                         $expires = time() + $ttl;
1159
1160                         if ( $this->swiftTempUrlKey != '' ) {
1161                                 $url = $this->storageUrl( $auth, $srcCont, $srcRel );
1162                                 // Swift wants the signature based on the unencoded object name
1163                                 $contPath = parse_url( $this->storageUrl( $auth, $srcCont ), PHP_URL_PATH );
1164                                 $signature = hash_hmac( 'sha1',
1165                                         "GET\n{$expires}\n{$contPath}/{$srcRel}",
1166                                         $this->swiftTempUrlKey
1167                                 );
1168
1169                                 return "{$url}?temp_url_sig={$signature}&temp_url_expires={$expires}";
1170                         } else { // give S3 API URL for rgw
1171                                 // Path for signature starts with the bucket
1172                                 $spath = '/' . rawurlencode( $srcCont ) . '/' .
1173                                         str_replace( '%2F', '/', rawurlencode( $srcRel ) );
1174                                 // Calculate the hash
1175                                 $signature = base64_encode( hash_hmac(
1176                                         'sha1',
1177                                         "GET\n\n\n{$expires}\n{$spath}",
1178                                         $this->rgwS3SecretKey,
1179                                         true // raw
1180                                 ) );
1181                                 // See http://s3.amazonaws.com/doc/s3-developer-guide/RESTAuthentication.html.
1182                                 // Note: adding a newline for empty CanonicalizedAmzHeaders does not work.
1183                                 return wfAppendQuery(
1184                                         str_replace( '/swift/v1', '', // S3 API is the rgw default
1185                                                 $this->storageUrl( $auth ) . $spath ),
1186                                         array(
1187                                                 'Signature' => $signature,
1188                                                 'Expires' => $expires,
1189                                                 'AWSAccessKeyId' => $this->rgwS3AccessKey )
1190                                 );
1191                         }
1192                 }
1193
1194                 return null;
1195         }
1196
1197         protected function directoriesAreVirtual() {
1198                 return true;
1199         }
1200
1201         /**
1202          * Get headers to send to Swift when reading a file based
1203          * on a FileBackend params array, e.g. that of getLocalCopy().
1204          * $params is currently only checked for a 'latest' flag.
1205          *
1206          * @param array $params
1207          * @return array
1208          */
1209         protected function headersFromParams( array $params ) {
1210                 $hdrs = array();
1211                 if ( !empty( $params['latest'] ) ) {
1212                         $hdrs['x-newest'] = 'true';
1213                 }
1214
1215                 return $hdrs;
1216         }
1217
1218         /**
1219          * @param FileBackendStoreOpHandle[] $fileOpHandles
1220          *
1221          * @return Status[]
1222          */
1223         protected function doExecuteOpHandlesInternal( array $fileOpHandles ) {
1224                 $statuses = array();
1225
1226                 $auth = $this->getAuthentication();
1227                 if ( !$auth ) {
1228                         foreach ( $fileOpHandles as $index => $fileOpHandle ) {
1229                                 $statuses[$index] = Status::newFatal( 'backend-fail-connect', $this->name );
1230                         }
1231
1232                         return $statuses;
1233                 }
1234
1235                 // Split the HTTP requests into stages that can be done concurrently
1236                 $httpReqsByStage = array(); // map of (stage => index => HTTP request)
1237                 foreach ( $fileOpHandles as $index => $fileOpHandle ) {
1238                         $reqs = $fileOpHandle->httpOp;
1239                         // Convert the 'url' parameter to an actual URL using $auth
1240                         foreach ( $reqs as $stage => &$req ) {
1241                                 list( $container, $relPath ) = $req['url'];
1242                                 $req['url'] = $this->storageUrl( $auth, $container, $relPath );
1243                                 $req['headers'] = isset( $req['headers'] ) ? $req['headers'] : array();
1244                                 $req['headers'] = $this->authTokenHeaders( $auth ) + $req['headers'];
1245                                 $httpReqsByStage[$stage][$index] = $req;
1246                         }
1247                         $statuses[$index] = Status::newGood();
1248                 }
1249
1250                 // Run all requests for the first stage, then the next, and so on
1251                 $reqCount = count( $httpReqsByStage );
1252                 for ( $stage = 0; $stage < $reqCount; ++$stage ) {
1253                         $httpReqs = $this->http->runMulti( $httpReqsByStage[$stage] );
1254                         foreach ( $httpReqs as $index => $httpReq ) {
1255                                 // Run the callback for each request of this operation
1256                                 $callback = $fileOpHandles[$index]->callback;
1257                                 call_user_func_array( $callback, array( $httpReq, $statuses[$index] ) );
1258                                 // On failure, abort all remaining requests for this operation
1259                                 // (e.g. abort the DELETE request if the COPY request fails for a move)
1260                                 if ( !$statuses[$index]->isOK() ) {
1261                                         $stages = count( $fileOpHandles[$index]->httpOp );
1262                                         for ( $s = ( $stage + 1 ); $s < $stages; ++$s ) {
1263                                                 unset( $httpReqsByStage[$s][$index] );
1264                                         }
1265                                 }
1266                         }
1267                 }
1268
1269                 return $statuses;
1270         }
1271
1272         /**
1273          * Set read/write permissions for a Swift container.
1274          *
1275          * @see http://swift.openstack.org/misc.html#acls
1276          *
1277          * In general, we don't allow listings to end-users. It's not useful, isn't well-defined
1278          * (lists are truncated to 10000 item with no way to page), and is just a performance risk.
1279          *
1280          * @param string $container Resolved Swift container
1281          * @param array $readGrps List of the possible criteria for a request to have
1282          * access to read a container. Each item is one of the following formats:
1283          *   - account:user        : Grants access if the request is by the given user
1284          *   - ".r:<regex>"        : Grants access if the request is from a referrer host that
1285          *                           matches the expression and the request is not for a listing.
1286          *                           Setting this to '*' effectively makes a container public.
1287          *   -".rlistings:<regex>" : Grants access if the request is from a referrer host that
1288          *                           matches the expression and the request is for a listing.
1289          * @param array $writeGrps A list of the possible criteria for a request to have
1290          * access to write to a container. Each item is of the following format:
1291          *   - account:user       : Grants access if the request is by the given user
1292          * @return Status
1293          */
1294         protected function setContainerAccess( $container, array $readGrps, array $writeGrps ) {
1295                 $status = Status::newGood();
1296                 $auth = $this->getAuthentication();
1297
1298                 if ( !$auth ) {
1299                         $status->fatal( 'backend-fail-connect', $this->name );
1300
1301                         return $status;
1302                 }
1303
1304                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1305                         'method' => 'POST',
1306                         'url' => $this->storageUrl( $auth, $container ),
1307                         'headers' => $this->authTokenHeaders( $auth ) + array(
1308                                 'x-container-read' => implode( ',', $readGrps ),
1309                                 'x-container-write' => implode( ',', $writeGrps )
1310                         )
1311                 ) );
1312
1313                 if ( $rcode != 204 && $rcode !== 202 ) {
1314                         $status->fatal( 'backend-fail-internal', $this->name );
1315                         wfDebugLog( 'SwiftBackend', __METHOD__ . ': unexpected rcode value (' . $rcode . ')' );
1316                 }
1317
1318                 return $status;
1319         }
1320
1321         /**
1322          * Get a Swift container stat array, possibly from process cache.
1323          * Use $reCache if the file count or byte count is needed.
1324          *
1325          * @param string $container Container name
1326          * @param bool $bypassCache Bypass all caches and load from Swift
1327          * @return array|bool|null False on 404, null on failure
1328          */
1329         protected function getContainerStat( $container, $bypassCache = false ) {
1330                 $ps = Profiler::instance()->scopedProfileIn( __METHOD__ . "-{$this->name}" );
1331
1332                 if ( $bypassCache ) { // purge cache
1333                         $this->containerStatCache->clear( $container );
1334                 } elseif ( !$this->containerStatCache->has( $container, 'stat' ) ) {
1335                         $this->primeContainerCache( array( $container ) ); // check persistent cache
1336                 }
1337                 if ( !$this->containerStatCache->has( $container, 'stat' ) ) {
1338                         $auth = $this->getAuthentication();
1339                         if ( !$auth ) {
1340                                 return null;
1341                         }
1342
1343                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1344                                 'method' => 'HEAD',
1345                                 'url' => $this->storageUrl( $auth, $container ),
1346                                 'headers' => $this->authTokenHeaders( $auth )
1347                         ) );
1348
1349                         if ( $rcode === 204 ) {
1350                                 $stat = array(
1351                                         'count' => $rhdrs['x-container-object-count'],
1352                                         'bytes' => $rhdrs['x-container-bytes-used']
1353                                 );
1354                                 if ( $bypassCache ) {
1355                                         return $stat;
1356                                 } else {
1357                                         $this->containerStatCache->set( $container, 'stat', $stat ); // cache it
1358                                         $this->setContainerCache( $container, $stat ); // update persistent cache
1359                                 }
1360                         } elseif ( $rcode === 404 ) {
1361                                 return false;
1362                         } else {
1363                                 $this->onError( null, __METHOD__,
1364                                         array( 'cont' => $container ), $rerr, $rcode, $rdesc );
1365
1366                                 return null;
1367                         }
1368                 }
1369
1370                 return $this->containerStatCache->get( $container, 'stat' );
1371         }
1372
1373         /**
1374          * Create a Swift container
1375          *
1376          * @param string $container Container name
1377          * @param array $params
1378          * @return Status
1379          */
1380         protected function createContainer( $container, array $params ) {
1381                 $status = Status::newGood();
1382
1383                 $auth = $this->getAuthentication();
1384                 if ( !$auth ) {
1385                         $status->fatal( 'backend-fail-connect', $this->name );
1386
1387                         return $status;
1388                 }
1389
1390                 // @see SwiftFileBackend::setContainerAccess()
1391                 if ( empty( $params['noAccess'] ) ) {
1392                         $readGrps = array( '.r:*', $this->swiftUser ); // public
1393                 } else {
1394                         $readGrps = array( $this->swiftUser ); // private
1395                 }
1396                 $writeGrps = array( $this->swiftUser ); // sanity
1397
1398                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1399                         'method' => 'PUT',
1400                         'url' => $this->storageUrl( $auth, $container ),
1401                         'headers' => $this->authTokenHeaders( $auth ) + array(
1402                                 'x-container-read' => implode( ',', $readGrps ),
1403                                 'x-container-write' => implode( ',', $writeGrps )
1404                         )
1405                 ) );
1406
1407                 if ( $rcode === 201 ) { // new
1408                         // good
1409                 } elseif ( $rcode === 202 ) { // already there
1410                         // this shouldn't really happen, but is OK
1411                 } else {
1412                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc );
1413                 }
1414
1415                 return $status;
1416         }
1417
1418         /**
1419          * Delete a Swift container
1420          *
1421          * @param string $container Container name
1422          * @param array $params
1423          * @return Status
1424          */
1425         protected function deleteContainer( $container, array $params ) {
1426                 $status = Status::newGood();
1427
1428                 $auth = $this->getAuthentication();
1429                 if ( !$auth ) {
1430                         $status->fatal( 'backend-fail-connect', $this->name );
1431
1432                         return $status;
1433                 }
1434
1435                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1436                         'method' => 'DELETE',
1437                         'url' => $this->storageUrl( $auth, $container ),
1438                         'headers' => $this->authTokenHeaders( $auth )
1439                 ) );
1440
1441                 if ( $rcode >= 200 && $rcode <= 299 ) { // deleted
1442                         $this->containerStatCache->clear( $container ); // purge
1443                 } elseif ( $rcode === 404 ) { // not there
1444                         // this shouldn't really happen, but is OK
1445                 } elseif ( $rcode === 409 ) { // not empty
1446                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc ); // race?
1447                 } else {
1448                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc );
1449                 }
1450
1451                 return $status;
1452         }
1453
1454         /**
1455          * Get a list of objects under a container.
1456          * Either just the names or a list of stdClass objects with details can be returned.
1457          *
1458          * @param string $fullCont
1459          * @param string $type ('info' for a list of object detail maps, 'names' for names only)
1460          * @param int $limit
1461          * @param string|null $after
1462          * @param string|null $prefix
1463          * @param string|null $delim
1464          * @return Status With the list as value
1465          */
1466         private function objectListing(
1467                 $fullCont, $type, $limit, $after = null, $prefix = null, $delim = null
1468         ) {
1469                 $status = Status::newGood();
1470
1471                 $auth = $this->getAuthentication();
1472                 if ( !$auth ) {
1473                         $status->fatal( 'backend-fail-connect', $this->name );
1474
1475                         return $status;
1476                 }
1477
1478                 $query = array( 'limit' => $limit );
1479                 if ( $type === 'info' ) {
1480                         $query['format'] = 'json';
1481                 }
1482                 if ( $after !== null ) {
1483                         $query['marker'] = $after;
1484                 }
1485                 if ( $prefix !== null ) {
1486                         $query['prefix'] = $prefix;
1487                 }
1488                 if ( $delim !== null ) {
1489                         $query['delimiter'] = $delim;
1490                 }
1491
1492                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1493                         'method' => 'GET',
1494                         'url' => $this->storageUrl( $auth, $fullCont ),
1495                         'query' => $query,
1496                         'headers' => $this->authTokenHeaders( $auth )
1497                 ) );
1498
1499                 $params = array( 'cont' => $fullCont, 'prefix' => $prefix, 'delim' => $delim );
1500                 if ( $rcode === 200 ) { // good
1501                         if ( $type === 'info' ) {
1502                                 $status->value = FormatJson::decode( trim( $rbody ) );
1503                         } else {
1504                                 $status->value = explode( "\n", trim( $rbody ) );
1505                         }
1506                 } elseif ( $rcode === 204 ) {
1507                         $status->value = array(); // empty container
1508                 } elseif ( $rcode === 404 ) {
1509                         $status->value = array(); // no container
1510                 } else {
1511                         $this->onError( $status, __METHOD__, $params, $rerr, $rcode, $rdesc );
1512                 }
1513
1514                 return $status;
1515         }
1516
1517         protected function doPrimeContainerCache( array $containerInfo ) {
1518                 foreach ( $containerInfo as $container => $info ) {
1519                         $this->containerStatCache->set( $container, 'stat', $info );
1520                 }
1521         }
1522
1523         protected function doGetFileStatMulti( array $params ) {
1524                 $stats = array();
1525
1526                 $auth = $this->getAuthentication();
1527
1528                 $reqs = array();
1529                 foreach ( $params['srcs'] as $path ) {
1530                         list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $path );
1531                         if ( $srcRel === null ) {
1532                                 $stats[$path] = false;
1533                                 continue; // invalid storage path
1534                         } elseif ( !$auth ) {
1535                                 $stats[$path] = null;
1536                                 continue;
1537                         }
1538
1539                         // (a) Check the container
1540                         $cstat = $this->getContainerStat( $srcCont );
1541                         if ( $cstat === false ) {
1542                                 $stats[$path] = false;
1543                                 continue; // ok, nothing to do
1544                         } elseif ( !is_array( $cstat ) ) {
1545                                 $stats[$path] = null;
1546                                 continue;
1547                         }
1548
1549                         $reqs[$path] = array(
1550                                 'method'  => 'HEAD',
1551                                 'url'     => $this->storageUrl( $auth, $srcCont, $srcRel ),
1552                                 'headers' => $this->authTokenHeaders( $auth ) + $this->headersFromParams( $params )
1553                         );
1554                 }
1555
1556                 $opts = array( 'maxConnsPerHost' => $params['concurrency'] );
1557                 $reqs = $this->http->runMulti( $reqs, $opts );
1558
1559                 foreach ( $params['srcs'] as $path ) {
1560                         if ( array_key_exists( $path, $stats ) ) {
1561                                 continue; // some sort of failure above
1562                         }
1563                         // (b) Check the file
1564                         list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $reqs[$path]['response'];
1565                         if ( $rcode === 200 || $rcode === 204 ) {
1566                                 // Update the object if it is missing some headers
1567                                 $rhdrs = $this->addMissingMetadata( $rhdrs, $path );
1568                                 // Load the stat array from the headers
1569                                 $stat = $this->getStatFromHeaders( $rhdrs );
1570                                 if ( $this->isRGW ) {
1571                                         $stat['latest'] = true; // strong consistency
1572                                 }
1573                         } elseif ( $rcode === 404 ) {
1574                                 $stat = false;
1575                         } else {
1576                                 $stat = null;
1577                                 $this->onError( null, __METHOD__, $params, $rerr, $rcode, $rdesc );
1578                         }
1579                         $stats[$path] = $stat;
1580                 }
1581
1582                 return $stats;
1583         }
1584
1585         /**
1586          * @param array $rhdrs
1587          * @return array
1588          */
1589         protected function getStatFromHeaders( array $rhdrs ) {
1590                 // Fetch all of the custom metadata headers
1591                 $metadata = $this->getMetadata( $rhdrs );
1592                 // Fetch all of the custom raw HTTP headers
1593                 $headers = $this->sanitizeHdrs( array( 'headers' => $rhdrs ) );
1594
1595                 return array(
1596                         // Convert various random Swift dates to TS_MW
1597                         'mtime' => $this->convertSwiftDate( $rhdrs['last-modified'], TS_MW ),
1598                         // Empty objects actually return no content-length header in Ceph
1599                         'size'  => isset( $rhdrs['content-length'] ) ? (int)$rhdrs['content-length'] : 0,
1600                         'sha1'  => isset( $metadata['sha1base36'] ) ? $metadata['sha1base36'] : null,
1601                         // Note: manifiest ETags are not an MD5 of the file
1602                         'md5'   => ctype_xdigit( $rhdrs['etag'] ) ? $rhdrs['etag'] : null,
1603                         'xattr' => array( 'metadata' => $metadata, 'headers' => $headers )
1604                 );
1605         }
1606
1607         /**
1608          * @return array|null Credential map
1609          */
1610         protected function getAuthentication() {
1611                 if ( $this->authErrorTimestamp !== null ) {
1612                         if ( ( time() - $this->authErrorTimestamp ) < 60 ) {
1613                                 return null; // failed last attempt; don't bother
1614                         } else { // actually retry this time
1615                                 $this->authErrorTimestamp = null;
1616                         }
1617                 }
1618                 // Session keys expire after a while, so we renew them periodically
1619                 $reAuth = ( ( time() - $this->authSessionTimestamp ) > $this->authTTL );
1620                 // Authenticate with proxy and get a session key...
1621                 if ( !$this->authCreds || $reAuth ) {
1622                         $this->authSessionTimestamp = 0;
1623                         $cacheKey = $this->getCredsCacheKey( $this->swiftUser );
1624                         $creds = $this->srvCache->get( $cacheKey ); // credentials
1625                         // Try to use the credential cache
1626                         if ( isset( $creds['auth_token'] ) && isset( $creds['storage_url'] ) ) {
1627                                 $this->authCreds = $creds;
1628                                 // Skew the timestamp for worst case to avoid using stale credentials
1629                                 $this->authSessionTimestamp = time() - ceil( $this->authTTL / 2 );
1630                         } else { // cache miss
1631                                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->http->run( array(
1632                                         'method' => 'GET',
1633                                         'url' => "{$this->swiftAuthUrl}/v1.0",
1634                                         'headers' => array(
1635                                                 'x-auth-user' => $this->swiftUser,
1636                                                 'x-auth-key' => $this->swiftKey
1637                                         )
1638                                 ) );
1639
1640                                 if ( $rcode >= 200 && $rcode <= 299 ) { // OK
1641                                         $this->authCreds = array(
1642                                                 'auth_token' => $rhdrs['x-auth-token'],
1643                                                 'storage_url' => $rhdrs['x-storage-url']
1644                                         );
1645                                         $this->srvCache->set( $cacheKey, $this->authCreds, ceil( $this->authTTL / 2 ) );
1646                                         $this->authSessionTimestamp = time();
1647                                 } elseif ( $rcode === 401 ) {
1648                                         $this->onError( null, __METHOD__, array(), "Authentication failed.", $rcode );
1649                                         $this->authErrorTimestamp = time();
1650
1651                                         return null;
1652                                 } else {
1653                                         $this->onError( null, __METHOD__, array(), "HTTP return code: $rcode", $rcode );
1654                                         $this->authErrorTimestamp = time();
1655
1656                                         return null;
1657                                 }
1658                         }
1659                         // Ceph RGW does not use <account> in URLs (OpenStack Swift uses "/v1/<account>")
1660                         if ( substr( $this->authCreds['storage_url'], -3 ) === '/v1' ) {
1661                                 $this->isRGW = true; // take advantage of strong consistency in Ceph
1662                         }
1663                 }
1664
1665                 return $this->authCreds;
1666         }
1667
1668         /**
1669          * @param array $creds From getAuthentication()
1670          * @param string $container
1671          * @param string $object
1672          * @return array
1673          */
1674         protected function storageUrl( array $creds, $container = null, $object = null ) {
1675                 $parts = array( $creds['storage_url'] );
1676                 if ( strlen( $container ) ) {
1677                         $parts[] = rawurlencode( $container );
1678                 }
1679                 if ( strlen( $object ) ) {
1680                         $parts[] = str_replace( "%2F", "/", rawurlencode( $object ) );
1681                 }
1682
1683                 return implode( '/', $parts );
1684         }
1685
1686         /**
1687          * @param array $creds From getAuthentication()
1688          * @return array
1689          */
1690         protected function authTokenHeaders( array $creds ) {
1691                 return array( 'x-auth-token' => $creds['auth_token'] );
1692         }
1693
1694         /**
1695          * Get the cache key for a container
1696          *
1697          * @param string $username
1698          * @return string
1699          */
1700         private function getCredsCacheKey( $username ) {
1701                 return 'swiftcredentials:' . md5( $username . ':' . $this->swiftAuthUrl );
1702         }
1703
1704         /**
1705          * Log an unexpected exception for this backend.
1706          * This also sets the Status object to have a fatal error.
1707          *
1708          * @param Status|null $status
1709          * @param string $func
1710          * @param array $params
1711          * @param string $err Error string
1712          * @param int $code HTTP status
1713          * @param string $desc HTTP status description
1714          */
1715         public function onError( $status, $func, array $params, $err = '', $code = 0, $desc = '' ) {
1716                 if ( $status instanceof Status ) {
1717                         $status->fatal( 'backend-fail-internal', $this->name );
1718                 }
1719                 if ( $code == 401 ) { // possibly a stale token
1720                         $this->srvCache->delete( $this->getCredsCacheKey( $this->swiftUser ) );
1721                 }
1722                 wfDebugLog( 'SwiftBackend',
1723                         "HTTP $code ($desc) in '{$func}' (given '" . FormatJson::encode( $params ) . "')" .
1724                         ( $err ? ": $err" : "" )
1725                 );
1726         }
1727 }
1728
1729 /**
1730  * @see FileBackendStoreOpHandle
1731  */
1732 class SwiftFileOpHandle extends FileBackendStoreOpHandle {
1733         /** @var array List of Requests for MultiHttpClient */
1734         public $httpOp;
1735         /** @var Closure */
1736         public $callback;
1737
1738         /**
1739          * @param SwiftFileBackend $backend
1740          * @param Closure $callback Function that takes (HTTP request array, status)
1741          * @param array $httpOp MultiHttpClient op
1742          */
1743         public function __construct( SwiftFileBackend $backend, Closure $callback, array $httpOp ) {
1744                 $this->backend = $backend;
1745                 $this->callback = $callback;
1746                 $this->httpOp = $httpOp;
1747         }
1748 }
1749
1750 /**
1751  * SwiftFileBackend helper class to page through listings.
1752  * Swift also has a listing limit of 10,000 objects for sanity.
1753  * Do not use this class from places outside SwiftFileBackend.
1754  *
1755  * @ingroup FileBackend
1756  */
1757 abstract class SwiftFileBackendList implements Iterator {
1758         /** @var array List of path or (path,stat array) entries */
1759         protected $bufferIter = array();
1760
1761         /** @var string List items *after* this path */
1762         protected $bufferAfter = null;
1763
1764         /** @var int */
1765         protected $pos = 0;
1766
1767         /** @var array */
1768         protected $params = array();
1769
1770         /** @var SwiftFileBackend */
1771         protected $backend;
1772
1773         /** @var string Container name */
1774         protected $container;
1775
1776         /** @var string Storage directory */
1777         protected $dir;
1778
1779         /** @var int */
1780         protected $suffixStart;
1781
1782         const PAGE_SIZE = 9000; // file listing buffer size
1783
1784         /**
1785          * @param SwiftFileBackend $backend
1786          * @param string $fullCont Resolved container name
1787          * @param string $dir Resolved directory relative to container
1788          * @param array $params
1789          */
1790         public function __construct( SwiftFileBackend $backend, $fullCont, $dir, array $params ) {
1791                 $this->backend = $backend;
1792                 $this->container = $fullCont;
1793                 $this->dir = $dir;
1794                 if ( substr( $this->dir, -1 ) === '/' ) {
1795                         $this->dir = substr( $this->dir, 0, -1 ); // remove trailing slash
1796                 }
1797                 if ( $this->dir == '' ) { // whole container
1798                         $this->suffixStart = 0;
1799                 } else { // dir within container
1800                         $this->suffixStart = strlen( $this->dir ) + 1; // size of "path/to/dir/"
1801                 }
1802                 $this->params = $params;
1803         }
1804
1805         /**
1806          * @see Iterator::key()
1807          * @return int
1808          */
1809         public function key() {
1810                 return $this->pos;
1811         }
1812
1813         /**
1814          * @see Iterator::next()
1815          */
1816         public function next() {
1817                 // Advance to the next file in the page
1818                 next( $this->bufferIter );
1819                 ++$this->pos;
1820                 // Check if there are no files left in this page and
1821                 // advance to the next page if this page was not empty.
1822                 if ( !$this->valid() && count( $this->bufferIter ) ) {
1823                         $this->bufferIter = $this->pageFromList(
1824                                 $this->container, $this->dir, $this->bufferAfter, self::PAGE_SIZE, $this->params
1825                         ); // updates $this->bufferAfter
1826                 }
1827         }
1828
1829         /**
1830          * @see Iterator::rewind()
1831          */
1832         public function rewind() {
1833                 $this->pos = 0;
1834                 $this->bufferAfter = null;
1835                 $this->bufferIter = $this->pageFromList(
1836                         $this->container, $this->dir, $this->bufferAfter, self::PAGE_SIZE, $this->params
1837                 ); // updates $this->bufferAfter
1838         }
1839
1840         /**
1841          * @see Iterator::valid()
1842          * @return bool
1843          */
1844         public function valid() {
1845                 if ( $this->bufferIter === null ) {
1846                         return false; // some failure?
1847                 } else {
1848                         return ( current( $this->bufferIter ) !== false ); // no paths can have this value
1849                 }
1850         }
1851
1852         /**
1853          * Get the given list portion (page)
1854          *
1855          * @param string $container Resolved container name
1856          * @param string $dir Resolved path relative to container
1857          * @param string $after
1858          * @param int $limit
1859          * @param array $params
1860          * @return Traversable|array
1861          */
1862         abstract protected function pageFromList( $container, $dir, &$after, $limit, array $params );
1863 }
1864
1865 /**
1866  * Iterator for listing directories
1867  */
1868 class SwiftFileBackendDirList extends SwiftFileBackendList {
1869         /**
1870          * @see Iterator::current()
1871          * @return string|bool String (relative path) or false
1872          */
1873         public function current() {
1874                 return substr( current( $this->bufferIter ), $this->suffixStart, -1 );
1875         }
1876
1877         protected function pageFromList( $container, $dir, &$after, $limit, array $params ) {
1878                 return $this->backend->getDirListPageInternal( $container, $dir, $after, $limit, $params );
1879         }
1880 }
1881
1882 /**
1883  * Iterator for listing regular files
1884  */
1885 class SwiftFileBackendFileList extends SwiftFileBackendList {
1886         /**
1887          * @see Iterator::current()
1888          * @return string|bool String (relative path) or false
1889          */
1890         public function current() {
1891                 list( $path, $stat ) = current( $this->bufferIter );
1892                 $relPath = substr( $path, $this->suffixStart );
1893                 if ( is_array( $stat ) ) {
1894                         $storageDir = rtrim( $this->params['dir'], '/' );
1895                         $this->backend->loadListingStatInternal( "$storageDir/$relPath", $stat );
1896                 }
1897
1898                 return $relPath;
1899         }
1900
1901         protected function pageFromList( $container, $dir, &$after, $limit, array $params ) {
1902                 return $this->backend->getFileListPageInternal( $container, $dir, $after, $limit, $params );
1903         }
1904 }