includes/filebackend/FileBackendMultiWrite.php

   1 <?php
   2 /**
   3  * Proxy backend that mirrors writes to several internal backends.
   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 Aaron Schulz
  23  */
  24
  25 /**
  26  * @brief Proxy backend that mirrors writes to several internal backends.
  27  *
  28  * This class defines a multi-write backend. Multiple backends can be
  29  * registered to this proxy backend and it will act as a single backend.
  30  * Use this when all access to those backends is through this proxy backend.
  31  * At least one of the backends must be declared the "master" backend.
  32  *
  33  * Only use this class when transitioning from one storage system to another.
  34  *
  35  * Read operations are only done on the 'master' backend for consistency.
  36  * Write operations are performed on all backends, starting with the master.
  37  * This makes a best-effort to have transactional semantics, but since requests
  38  * may sometimes fail, the use of "autoResync" or background scripts to fix
  39  * inconsistencies is important.
  40  *
  41  * @ingroup FileBackend
  42  * @since 1.19
  43  */
  44 class FileBackendMultiWrite extends FileBackend {
  45         /** @var FileBackendStore[] Prioritized list of FileBackendStore objects */
  46         protected $backends = [];
  47
  48         /** @var int Index of master backend */
  49         protected $masterIndex = -1;
  50         /** @var int Index of read affinity backend */
  51         protected $readIndex = -1;
  52
  53         /** @var int Bitfield */
  54         protected $syncChecks = 0;
  55         /** @var string|bool */
  56         protected $autoResync = false;
  57
  58         /** @var bool */
  59         protected $asyncWrites = false;
  60
  61         /* Possible internal backend consistency checks */
  62         const CHECK_SIZE = 1;
  63         const CHECK_TIME = 2;
  64         const CHECK_SHA1 = 4;
  65
  66         /**
  67          * Construct a proxy backend that consists of several internal backends.
  68          * Locking, journaling, and read-only checks are handled by the proxy backend.
  69          *
  70          * Additional $config params include:
  71          *   - backends       : Array of backend config and multi-backend settings.
  72          *                      Each value is the config used in the constructor of a
  73          *                      FileBackendStore class, but with these additional settings:
  74          *                        - class         : The name of the backend class
  75          *                        - isMultiMaster : This must be set for one backend.
  76          *                        - readAffinity  : Use this for reads without 'latest' set.
  77          *                        - template:     : If given a backend name, this will use
  78          *                                          the config of that backend as a template.
  79          *                                          Values specified here take precedence.
  80          *   - syncChecks     : Integer bitfield of internal backend sync checks to perform.
  81          *                      Possible bits include the FileBackendMultiWrite::CHECK_* constants.
  82          *                      There are constants for SIZE, TIME, and SHA1.
  83          *                      The checks are done before allowing any file operations.
  84          *   - autoResync     : Automatically resync the clone backends to the master backend
  85          *                      when pre-operation sync checks fail. This should only be used
  86          *                      if the master backend is stable and not missing any files.
  87          *                      Use "conservative" to limit resyncing to copying newer master
  88          *                      backend files over older (or non-existing) clone backend files.
  89          *                      Cases that cannot be handled will result in operation abortion.
  90          *   - replication    : Set to 'async' to defer file operations on the non-master backends.
  91          *                      This will apply such updates post-send for web requests. Note that
  92          *                      any checks from "syncChecks" are still synchronous.
  93          *
  94          * @param array $config
  95          * @throws FileBackendError
  96          */
  97         public function __construct( array $config ) {
  98                 parent::__construct( $config );
  99                 $this->syncChecks = isset( $config['syncChecks'] )
 100                         ? $config['syncChecks']
 101                         : self::CHECK_SIZE;
 102                 $this->autoResync = isset( $config['autoResync'] )
 103                         ? $config['autoResync']
 104                         : false;
 105                 $this->asyncWrites = isset( $config['replication'] ) && $config['replication'] === 'async';
 106                 // Construct backends here rather than via registration
 107                 // to keep these backends hidden from outside the proxy.
 108                 $namesUsed = [];
 109                 foreach ( $config['backends'] as $index => $config ) {
 110                         if ( isset( $config['template'] ) ) {
 111                                 // Config is just a modified version of a registered backend's.
 112                                 // This should only be used when that config is used only by this backend.
 113                                 $config = $config + FileBackendGroup::singleton()->config( $config['template'] );
 114                         }
 115                         $name = $config['name'];
 116                         if ( isset( $namesUsed[$name] ) ) { // don't break FileOp predicates
 117                                 throw new FileBackendError( "Two or more backends defined with the name $name." );
 118                         }
 119                         $namesUsed[$name] = 1;
 120                         // Alter certain sub-backend settings for sanity
 121                         unset( $config['readOnly'] ); // use proxy backend setting
 122                         unset( $config['fileJournal'] ); // use proxy backend journal
 123                         unset( $config['lockManager'] ); // lock under proxy backend
 124                         $config['wikiId'] = $this->wikiId; // use the proxy backend wiki ID
 125                         if ( !empty( $config['isMultiMaster'] ) ) {
 126                                 if ( $this->masterIndex >= 0 ) {
 127                                         throw new FileBackendError( 'More than one master backend defined.' );
 128                                 }
 129                                 $this->masterIndex = $index; // this is the "master"
 130                                 $config['fileJournal'] = $this->fileJournal; // log under proxy backend
 131                         }
 132                         if ( !empty( $config['readAffinity'] ) ) {
 133                                 $this->readIndex = $index; // prefer this for reads
 134                         }
 135                         // Create sub-backend object
 136                         if ( !isset( $config['class'] ) ) {
 137                                 throw new FileBackendError( 'No class given for a backend config.' );
 138                         }
 139                         $class = $config['class'];
 140                         $this->backends[$index] = new $class( $config );
 141                 }
 142                 if ( $this->masterIndex < 0 ) { // need backends and must have a master
 143                         throw new FileBackendError( 'No master backend defined.' );
 144                 }
 145                 if ( $this->readIndex < 0 ) {
 146                         $this->readIndex = $this->masterIndex; // default
 147                 }
 148         }
 149
 150         final protected function doOperationsInternal( array $ops, array $opts ) {
 151                 $status = Status::newGood();
 152
 153                 $mbe = $this->backends[$this->masterIndex]; // convenience
 154
 155                 // Try to lock those files for the scope of this function...
 156                 $scopeLock = null;
 157                 if ( empty( $opts['nonLocking'] ) ) {
 158                         // Try to lock those files for the scope of this function...
 159                         /** @noinspection PhpUnusedLocalVariableInspection */
 160                         $scopeLock = $this->getScopedLocksForOps( $ops, $status );
 161                         if ( !$status->isOK() ) {
 162                                 return $status; // abort
 163                         }
 164                 }
 165                 // Clear any cache entries (after locks acquired)
 166                 $this->clearCache();
 167                 $opts['preserveCache'] = true; // only locked files are cached
 168                 // Get the list of paths to read/write...
 169                 $relevantPaths = $this->fileStoragePathsForOps( $ops );
 170                 // Check if the paths are valid and accessible on all backends...
 171                 $status->merge( $this->accessibilityCheck( $relevantPaths ) );
 172                 if ( !$status->isOK() ) {
 173                         return $status; // abort
 174                 }
 175                 // Do a consistency check to see if the backends are consistent...
 176                 $syncStatus = $this->consistencyCheck( $relevantPaths );
 177                 if ( !$syncStatus->isOK() ) {
 178                         wfDebugLog( 'FileOperation', get_class( $this ) .
 179                                 " failed sync check: " . FormatJson::encode( $relevantPaths ) );
 180                         // Try to resync the clone backends to the master on the spot...
 181                         if ( $this->autoResync === false
 182                                 || !$this->resyncFiles( $relevantPaths, $this->autoResync )->isOK()
 183                         ) {
 184                                 $status->merge( $syncStatus );
 185
 186                                 return $status; // abort
 187                         }
 188                 }
 189                 // Actually attempt the operation batch on the master backend...
 190                 $realOps = $this->substOpBatchPaths( $ops, $mbe );
 191                 $masterStatus = $mbe->doOperations( $realOps, $opts );
 192                 $status->merge( $masterStatus );
 193                 // Propagate the operations to the clone backends if there were no unexpected errors
 194                 // and if there were either no expected errors or if the 'force' option was used.
 195                 // However, if nothing succeeded at all, then don't replicate any of the operations.
 196                 // If $ops only had one operation, this might avoid backend sync inconsistencies.
 197                 if ( $masterStatus->isOK() && $masterStatus->successCount > 0 ) {
 198                         foreach ( $this->backends as $index => $backend ) {
 199                                 if ( $index === $this->masterIndex ) {
 200                                         continue; // done already
 201                                 }
 202
 203                                 $realOps = $this->substOpBatchPaths( $ops, $backend );
 204                                 if ( $this->asyncWrites && !$this->hasVolatileSources( $ops ) ) {
 205                                         // Bind $scopeLock to the callback to preserve locks
 206                                         DeferredUpdates::addCallableUpdate(
 207                                                 function() use ( $backend, $realOps, $opts, $scopeLock, $relevantPaths ) {
 208                                                         wfDebugLog( 'FileOperationReplication',
 209                                                                 "'{$backend->getName()}' async replication; paths: " .
 210                                                                 FormatJson::encode( $relevantPaths ) );
 211                                                         $backend->doOperations( $realOps, $opts );
 212                                                 }
 213                                         );
 214                                 } else {
 215                                         wfDebugLog( 'FileOperationReplication',
 216                                                 "'{$backend->getName()}' sync replication; paths: " .
 217                                                 FormatJson::encode( $relevantPaths ) );
 218                                         $status->merge( $backend->doOperations( $realOps, $opts ) );
 219                                 }
 220                         }
 221                 }
 222                 // Make 'success', 'successCount', and 'failCount' fields reflect
 223                 // the overall operation, rather than all the batches for each backend.
 224                 // Do this by only using success values from the master backend's batch.
 225                 $status->success = $masterStatus->success;
 226                 $status->successCount = $masterStatus->successCount;
 227                 $status->failCount = $masterStatus->failCount;
 228
 229                 return $status;
 230         }
 231
 232         /**
 233          * Check that a set of files are consistent across all internal backends
 234          *
 235          * @param array $paths List of storage paths
 236          * @return Status
 237          */
 238         public function consistencyCheck( array $paths ) {
 239                 $status = Status::newGood();
 240                 if ( $this->syncChecks == 0 || count( $this->backends ) <= 1 ) {
 241                         return $status; // skip checks
 242                 }
 243
 244                 $mBackend = $this->backends[$this->masterIndex];
 245                 foreach ( $paths as $path ) {
 246                         $params = [ 'src' => $path, 'latest' => true ];
 247                         $mParams = $this->substOpPaths( $params, $mBackend );
 248                         // Stat the file on the 'master' backend
 249                         $mStat = $mBackend->getFileStat( $mParams );
 250                         if ( $this->syncChecks & self::CHECK_SHA1 ) {
 251                                 $mSha1 = $mBackend->getFileSha1Base36( $mParams );
 252                         } else {
 253                                 $mSha1 = false;
 254                         }
 255                         // Check if all clone backends agree with the master...
 256                         foreach ( $this->backends as $index => $cBackend ) {
 257                                 if ( $index === $this->masterIndex ) {
 258                                         continue; // master
 259                                 }
 260                                 $cParams = $this->substOpPaths( $params, $cBackend );
 261                                 $cStat = $cBackend->getFileStat( $cParams );
 262                                 if ( $mStat ) { // file is in master
 263                                         if ( !$cStat ) { // file should exist
 264                                                 $status->fatal( 'backend-fail-synced', $path );
 265                                                 continue;
 266                                         }
 267                                         if ( $this->syncChecks & self::CHECK_SIZE ) {
 268                                                 if ( $cStat['size'] != $mStat['size'] ) { // wrong size
 269                                                         $status->fatal( 'backend-fail-synced', $path );
 270                                                         continue;
 271                                                 }
 272                                         }
 273                                         if ( $this->syncChecks & self::CHECK_TIME ) {
 274                                                 $mTs = wfTimestamp( TS_UNIX, $mStat['mtime'] );
 275                                                 $cTs = wfTimestamp( TS_UNIX, $cStat['mtime'] );
 276                                                 if ( abs( $mTs - $cTs ) > 30 ) { // outdated file somewhere
 277                                                         $status->fatal( 'backend-fail-synced', $path );
 278                                                         continue;
 279                                                 }
 280                                         }
 281                                         if ( $this->syncChecks & self::CHECK_SHA1 ) {
 282                                                 if ( $cBackend->getFileSha1Base36( $cParams ) !== $mSha1 ) { // wrong SHA1
 283                                                         $status->fatal( 'backend-fail-synced', $path );
 284                                                         continue;
 285                                                 }
 286                                         }
 287                                 } else { // file is not in master
 288                                         if ( $cStat ) { // file should not exist
 289                                                 $status->fatal( 'backend-fail-synced', $path );
 290                                         }
 291                                 }
 292                         }
 293                 }
 294
 295                 return $status;
 296         }
 297
 298         /**
 299          * Check that a set of file paths are usable across all internal backends
 300          *
 301          * @param array $paths List of storage paths
 302          * @return Status
 303          */
 304         public function accessibilityCheck( array $paths ) {
 305                 $status = Status::newGood();
 306                 if ( count( $this->backends ) <= 1 ) {
 307                         return $status; // skip checks
 308                 }
 309
 310                 foreach ( $paths as $path ) {
 311                         foreach ( $this->backends as $backend ) {
 312                                 $realPath = $this->substPaths( $path, $backend );
 313                                 if ( !$backend->isPathUsableInternal( $realPath ) ) {
 314                                         $status->fatal( 'backend-fail-usable', $path );
 315                                 }
 316                         }
 317                 }
 318
 319                 return $status;
 320         }
 321
 322         /**
 323          * Check that a set of files are consistent across all internal backends
 324          * and re-synchronize those files against the "multi master" if needed.
 325          *
 326          * @param array $paths List of storage paths
 327          * @param string|bool $resyncMode False, True, or "conservative"; see __construct()
 328          * @return Status
 329          */
 330         public function resyncFiles( array $paths, $resyncMode = true ) {
 331                 $status = Status::newGood();
 332
 333                 $mBackend = $this->backends[$this->masterIndex];
 334                 foreach ( $paths as $path ) {
 335                         $mPath = $this->substPaths( $path, $mBackend );
 336                         $mSha1 = $mBackend->getFileSha1Base36( [ 'src' => $mPath, 'latest' => true ] );
 337                         $mStat = $mBackend->getFileStat( [ 'src' => $mPath, 'latest' => true ] );
 338                         if ( $mStat === null || ( $mSha1 !== false && !$mStat ) ) { // sanity
 339                                 $status->fatal( 'backend-fail-internal', $this->name );
 340                                 wfDebugLog( 'FileOperation', __METHOD__
 341                                         . ': File is not available on the master backend' );
 342                                 continue; // file is not available on the master backend...
 343                         }
 344                         // Check of all clone backends agree with the master...
 345                         foreach ( $this->backends as $index => $cBackend ) {
 346                                 if ( $index === $this->masterIndex ) {
 347                                         continue; // master
 348                                 }
 349                                 $cPath = $this->substPaths( $path, $cBackend );
 350                                 $cSha1 = $cBackend->getFileSha1Base36( [ 'src' => $cPath, 'latest' => true ] );
 351                                 $cStat = $cBackend->getFileStat( [ 'src' => $cPath, 'latest' => true ] );
 352                                 if ( $cStat === null || ( $cSha1 !== false && !$cStat ) ) { // sanity
 353                                         $status->fatal( 'backend-fail-internal', $cBackend->getName() );
 354                                         wfDebugLog( 'FileOperation', __METHOD__ .
 355                                                 ': File is not available on the clone backend' );
 356                                         continue; // file is not available on the clone backend...
 357                                 }
 358                                 if ( $mSha1 === $cSha1 ) {
 359                                         // already synced; nothing to do
 360                                 } elseif ( $mSha1 !== false ) { // file is in master
 361                                         if ( $resyncMode === 'conservative'
 362                                                 && $cStat && $cStat['mtime'] > $mStat['mtime']
 363                                         ) {
 364                                                 $status->fatal( 'backend-fail-synced', $path );
 365                                                 continue; // don't rollback data
 366                                         }
 367                                         $fsFile = $mBackend->getLocalReference(
 368                                                 [ 'src' => $mPath, 'latest' => true ] );
 369                                         $status->merge( $cBackend->quickStore(
 370                                                 [ 'src' => $fsFile->getPath(), 'dst' => $cPath ]
 371                                         ) );
 372                                 } elseif ( $mStat === false ) { // file is not in master
 373                                         if ( $resyncMode === 'conservative' ) {
 374                                                 $status->fatal( 'backend-fail-synced', $path );
 375                                                 continue; // don't delete data
 376                                         }
 377                                         $status->merge( $cBackend->quickDelete( [ 'src' => $cPath ] ) );
 378                                 }
 379                         }
 380                 }
 381
 382                 return $status;
 383         }
 384
 385         /**
 386          * Get a list of file storage paths to read or write for a list of operations
 387          *
 388          * @param array $ops Same format as doOperations()
 389          * @return array List of storage paths to files (does not include directories)
 390          */
 391         protected function fileStoragePathsForOps( array $ops ) {
 392                 $paths = [];
 393                 foreach ( $ops as $op ) {
 394                         if ( isset( $op['src'] ) ) {
 395                                 // For things like copy/move/delete with "ignoreMissingSource" and there
 396                                 // is no source file, nothing should happen and there should be no errors.
 397                                 if ( empty( $op['ignoreMissingSource'] )
 398                                         || $this->fileExists( [ 'src' => $op['src'] ] )
 399                                 ) {
 400                                         $paths[] = $op['src'];
 401                                 }
 402                         }
 403                         if ( isset( $op['srcs'] ) ) {
 404                                 $paths = array_merge( $paths, $op['srcs'] );
 405                         }
 406                         if ( isset( $op['dst'] ) ) {
 407                                 $paths[] = $op['dst'];
 408                         }
 409                 }
 410
 411                 return array_values( array_unique( array_filter( $paths, 'FileBackend::isStoragePath' ) ) );
 412         }
 413
 414         /**
 415          * Substitute the backend name in storage path parameters
 416          * for a set of operations with that of a given internal backend.
 417          *
 418          * @param array $ops List of file operation arrays
 419          * @param FileBackendStore $backend
 420          * @return array
 421          */
 422         protected function substOpBatchPaths( array $ops, FileBackendStore $backend ) {
 423                 $newOps = []; // operations
 424                 foreach ( $ops as $op ) {
 425                         $newOp = $op; // operation
 426                         foreach ( [ 'src', 'srcs', 'dst', 'dir' ] as $par ) {
 427                                 if ( isset( $newOp[$par] ) ) { // string or array
 428                                         $newOp[$par] = $this->substPaths( $newOp[$par], $backend );
 429                                 }
 430                         }
 431                         $newOps[] = $newOp;
 432                 }
 433
 434                 return $newOps;
 435         }
 436
 437         /**
 438          * Same as substOpBatchPaths() but for a single operation
 439          *
 440          * @param array $ops File operation array
 441          * @param FileBackendStore $backend
 442          * @return array
 443          */
 444         protected function substOpPaths( array $ops, FileBackendStore $backend ) {
 445                 $newOps = $this->substOpBatchPaths( [ $ops ], $backend );
 446
 447                 return $newOps[0];
 448         }
 449
 450         /**
 451          * Substitute the backend of storage paths with an internal backend's name
 452          *
 453          * @param array|string $paths List of paths or single string path
 454          * @param FileBackendStore $backend
 455          * @return array|string
 456          */
 457         protected function substPaths( $paths, FileBackendStore $backend ) {
 458                 return preg_replace(
 459                         '!^mwstore://' . preg_quote( $this->name, '!' ) . '/!',
 460                         StringUtils::escapeRegexReplacement( "mwstore://{$backend->getName()}/" ),
 461                         $paths // string or array
 462                 );
 463         }
 464
 465         /**
 466          * Substitute the backend of internal storage paths with the proxy backend's name
 467          *
 468          * @param array|string $paths List of paths or single string path
 469          * @return array|string
 470          */
 471         protected function unsubstPaths( $paths ) {
 472                 return preg_replace(
 473                         '!^mwstore://([^/]+)!',
 474                         StringUtils::escapeRegexReplacement( "mwstore://{$this->name}" ),
 475                         $paths // string or array
 476                 );
 477         }
 478
 479         /**
 480          * @param array $ops File operations for FileBackend::doOperations()
 481          * @return bool Whether there are file path sources with outside lifetime/ownership
 482          */
 483         protected function hasVolatileSources( array $ops ) {
 484                 foreach ( $ops as $op ) {
 485                         if ( $op['op'] === 'store' && !isset( $op['srcRef'] ) ) {
 486                                 return true; // source file might be deleted anytime after do*Operations()
 487                         }
 488                 }
 489
 490                 return false;
 491         }
 492
 493         protected function doQuickOperationsInternal( array $ops ) {
 494                 $status = Status::newGood();
 495                 // Do the operations on the master backend; setting Status fields...
 496                 $realOps = $this->substOpBatchPaths( $ops, $this->backends[$this->masterIndex] );
 497                 $masterStatus = $this->backends[$this->masterIndex]->doQuickOperations( $realOps );
 498                 $status->merge( $masterStatus );
 499                 // Propagate the operations to the clone backends...
 500                 foreach ( $this->backends as $index => $backend ) {
 501                         if ( $index === $this->masterIndex ) {
 502                                 continue; // done already
 503                         }
 504
 505                         $realOps = $this->substOpBatchPaths( $ops, $backend );
 506                         if ( $this->asyncWrites && !$this->hasVolatileSources( $ops ) ) {
 507                                 DeferredUpdates::addCallableUpdate(
 508                                         function() use ( $backend, $realOps ) {
 509                                                 $backend->doQuickOperations( $realOps );
 510                                         }
 511                                 );
 512                         } else {
 513                                 $status->merge( $backend->doQuickOperations( $realOps ) );
 514                         }
 515                 }
 516                 // Make 'success', 'successCount', and 'failCount' fields reflect
 517                 // the overall operation, rather than all the batches for each backend.
 518                 // Do this by only using success values from the master backend's batch.
 519                 $status->success = $masterStatus->success;
 520                 $status->successCount = $masterStatus->successCount;
 521                 $status->failCount = $masterStatus->failCount;
 522
 523                 return $status;
 524         }
 525
 526         protected function doPrepare( array $params ) {
 527                 return $this->doDirectoryOp( 'prepare', $params );
 528         }
 529
 530         protected function doSecure( array $params ) {
 531                 return $this->doDirectoryOp( 'secure', $params );
 532         }
 533
 534         protected function doPublish( array $params ) {
 535                 return $this->doDirectoryOp( 'publish', $params );
 536         }
 537
 538         protected function doClean( array $params ) {
 539                 return $this->doDirectoryOp( 'clean', $params );
 540         }
 541
 542         /**
 543          * @param string $method One of (doPrepare,doSecure,doPublish,doClean)
 544          * @param array $params Method arguments
 545          * @return Status
 546          */
 547         protected function doDirectoryOp( $method, array $params ) {
 548                 $status = Status::newGood();
 549
 550                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 551                 $masterStatus = $this->backends[$this->masterIndex]->$method( $realParams );
 552                 $status->merge( $masterStatus );
 553
 554                 foreach ( $this->backends as $index => $backend ) {
 555                         if ( $index === $this->masterIndex ) {
 556                                 continue; // already done
 557                         }
 558
 559                         $realParams = $this->substOpPaths( $params, $backend );
 560                         if ( $this->asyncWrites ) {
 561                                 DeferredUpdates::addCallableUpdate(
 562                                         function() use ( $backend, $method, $realParams ) {
 563                                                 $backend->$method( $realParams );
 564                                         }
 565                                 );
 566                         } else {
 567                                 $status->merge( $backend->$method( $realParams ) );
 568                         }
 569                 }
 570
 571                 return $status;
 572         }
 573
 574         public function concatenate( array $params ) {
 575                 // We are writing to an FS file, so we don't need to do this per-backend
 576                 $index = $this->getReadIndexFromParams( $params );
 577                 $realParams = $this->substOpPaths( $params, $this->backends[$index] );
 578
 579                 return $this->backends[$index]->concatenate( $realParams );
 580         }
 581
 582         public function fileExists( array $params ) {
 583                 $index = $this->getReadIndexFromParams( $params );
 584                 $realParams = $this->substOpPaths( $params, $this->backends[$index] );
 585
 586                 return $this->backends[$index]->fileExists( $realParams );
 587         }
 588
 589         public function getFileTimestamp( array $params ) {
 590                 $index = $this->getReadIndexFromParams( $params );
 591                 $realParams = $this->substOpPaths( $params, $this->backends[$index] );
 592
 593                 return $this->backends[$index]->getFileTimestamp( $realParams );
 594         }
 595
 596         public function getFileSize( array $params ) {
 597                 $index = $this->getReadIndexFromParams( $params );
 598                 $realParams = $this->substOpPaths( $params, $this->backends[$index] );
 599
 600                 return $this->backends[$index]->getFileSize( $realParams );
 601         }
 602
 603         public function getFileStat( array $params ) {
 604                 $index = $this->getReadIndexFromParams( $params );
 605                 $realParams = $this->substOpPaths( $params, $this->backends[$index] );
 606
 607                 return $this->backends[$index]->getFileStat( $realParams );
 608         }
 609
 610         public function getFileXAttributes( array $params ) {
 611                 $index = $this->getReadIndexFromParams( $params );
 612                 $realParams = $this->substOpPaths( $params, $this->backends[$index] );
 613
 614                 return $this->backends[$index]->getFileXAttributes( $realParams );
 615         }
 616
 617         public function getFileContentsMulti( array $params ) {
 618                 $index = $this->getReadIndexFromParams( $params );
 619                 $realParams = $this->substOpPaths( $params, $this->backends[$index] );
 620
 621                 $contentsM = $this->backends[$index]->getFileContentsMulti( $realParams );
 622
 623                 $contents = []; // (path => FSFile) mapping using the proxy backend's name
 624                 foreach ( $contentsM as $path => $data ) {
 625                         $contents[$this->unsubstPaths( $path )] = $data;
 626                 }
 627
 628                 return $contents;
 629         }
 630
 631         public function getFileSha1Base36( array $params ) {
 632                 $index = $this->getReadIndexFromParams( $params );
 633                 $realParams = $this->substOpPaths( $params, $this->backends[$index] );
 634
 635                 return $this->backends[$index]->getFileSha1Base36( $realParams );
 636         }
 637
 638         public function getFileProps( array $params ) {
 639                 $index = $this->getReadIndexFromParams( $params );
 640                 $realParams = $this->substOpPaths( $params, $this->backends[$index] );
 641
 642                 return $this->backends[$index]->getFileProps( $realParams );
 643         }
 644
 645         public function streamFile( array $params ) {
 646                 $index = $this->getReadIndexFromParams( $params );
 647                 $realParams = $this->substOpPaths( $params, $this->backends[$index] );
 648
 649                 return $this->backends[$index]->streamFile( $realParams );
 650         }
 651
 652         public function getLocalReferenceMulti( array $params ) {
 653                 $index = $this->getReadIndexFromParams( $params );
 654                 $realParams = $this->substOpPaths( $params, $this->backends[$index] );
 655
 656                 $fsFilesM = $this->backends[$index]->getLocalReferenceMulti( $realParams );
 657
 658                 $fsFiles = []; // (path => FSFile) mapping using the proxy backend's name
 659                 foreach ( $fsFilesM as $path => $fsFile ) {
 660                         $fsFiles[$this->unsubstPaths( $path )] = $fsFile;
 661                 }
 662
 663                 return $fsFiles;
 664         }
 665
 666         public function getLocalCopyMulti( array $params ) {
 667                 $index = $this->getReadIndexFromParams( $params );
 668                 $realParams = $this->substOpPaths( $params, $this->backends[$index] );
 669
 670                 $tempFilesM = $this->backends[$index]->getLocalCopyMulti( $realParams );
 671
 672                 $tempFiles = []; // (path => TempFSFile) mapping using the proxy backend's name
 673                 foreach ( $tempFilesM as $path => $tempFile ) {
 674                         $tempFiles[$this->unsubstPaths( $path )] = $tempFile;
 675                 }
 676
 677                 return $tempFiles;
 678         }
 679
 680         public function getFileHttpUrl( array $params ) {
 681                 $index = $this->getReadIndexFromParams( $params );
 682                 $realParams = $this->substOpPaths( $params, $this->backends[$index] );
 683
 684                 return $this->backends[$index]->getFileHttpUrl( $realParams );
 685         }
 686
 687         public function directoryExists( array $params ) {
 688                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 689
 690                 return $this->backends[$this->masterIndex]->directoryExists( $realParams );
 691         }
 692
 693         public function getDirectoryList( array $params ) {
 694                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 695
 696                 return $this->backends[$this->masterIndex]->getDirectoryList( $realParams );
 697         }
 698
 699         public function getFileList( array $params ) {
 700                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 701
 702                 return $this->backends[$this->masterIndex]->getFileList( $realParams );
 703         }
 704
 705         public function getFeatures() {
 706                 return $this->backends[$this->masterIndex]->getFeatures();
 707         }
 708
 709         public function clearCache( array $paths = null ) {
 710                 foreach ( $this->backends as $backend ) {
 711                         $realPaths = is_array( $paths ) ? $this->substPaths( $paths, $backend ) : null;
 712                         $backend->clearCache( $realPaths );
 713                 }
 714         }
 715
 716         public function preloadCache( array $paths ) {
 717                 $realPaths = $this->substPaths( $paths, $this->backends[$this->readIndex] );
 718                 $this->backends[$this->readIndex]->preloadCache( $realPaths );
 719         }
 720
 721         public function preloadFileStat( array $params ) {
 722                 $index = $this->getReadIndexFromParams( $params );
 723                 $realParams = $this->substOpPaths( $params, $this->backends[$index] );
 724
 725                 return $this->backends[$index]->preloadFileStat( $realParams );
 726         }
 727
 728         public function getScopedLocksForOps( array $ops, Status $status ) {
 729                 $realOps = $this->substOpBatchPaths( $ops, $this->backends[$this->masterIndex] );
 730                 $fileOps = $this->backends[$this->masterIndex]->getOperationsInternal( $realOps );
 731                 // Get the paths to lock from the master backend
 732                 $paths = $this->backends[$this->masterIndex]->getPathsToLockForOpsInternal( $fileOps );
 733                 // Get the paths under the proxy backend's name
 734                 $pbPaths = [
 735                         LockManager::LOCK_UW => $this->unsubstPaths( $paths[LockManager::LOCK_UW] ),
 736                         LockManager::LOCK_EX => $this->unsubstPaths( $paths[LockManager::LOCK_EX] )
 737                 ];
 738
 739                 // Actually acquire the locks
 740                 return $this->getScopedFileLocks( $pbPaths, 'mixed', $status );
 741         }
 742
 743         /**
 744          * @param array $params
 745          * @return int The master or read affinity backend index, based on $params['latest']
 746          */
 747         protected function getReadIndexFromParams( array $params ) {
 748                 return !empty( $params['latest'] ) ? $this->masterIndex : $this->readIndex;
 749         }
 750 }