3 * Proxy backend that mirrors writes to several internal backends.
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.
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.
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
21 * @ingroup FileBackend
22 * @author Aaron Schulz
26 * @brief Proxy backend that mirrors writes to several internal backends.
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.
33 * Only use this class when transitioning from one storage system to another.
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.
41 * @ingroup FileBackend
44 class FileBackendMultiWrite
extends FileBackend
{
45 /** @var FileBackendStore[] Prioritized list of FileBackendStore objects */
46 protected $backends = [];
48 /** @var int Index of master backend */
49 protected $masterIndex = -1;
50 /** @var int Index of read affinity backend */
51 protected $readIndex = -1;
53 /** @var int Bitfield */
54 protected $syncChecks = 0;
55 /** @var string|bool */
56 protected $autoResync = false;
59 protected $asyncWrites = false;
61 /* Possible internal backend consistency checks */
67 * Construct a proxy backend that consists of several internal backends.
68 * Locking, journaling, and read-only checks are handled by the proxy backend.
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.
94 * @param array $config
95 * @throws FileBackendError
97 public function __construct( array $config ) {
98 parent
::__construct( $config );
99 $this->syncChecks
= isset( $config['syncChecks'] )
100 ?
$config['syncChecks']
102 $this->autoResync
= isset( $config['autoResync'] )
103 ?
$config['autoResync']
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.
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'] );
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." );
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.' );
129 $this->masterIndex
= $index; // this is the "master"
130 $config['fileJournal'] = $this->fileJournal
; // log under proxy backend
132 if ( !empty( $config['readAffinity'] ) ) {
133 $this->readIndex
= $index; // prefer this for reads
135 // Create sub-backend object
136 if ( !isset( $config['class'] ) ) {
137 throw new FileBackendError( 'No class given for a backend config.' );
139 $class = $config['class'];
140 $this->backends
[$index] = new $class( $config );
142 if ( $this->masterIndex
< 0 ) { // need backends and must have a master
143 throw new FileBackendError( 'No master backend defined.' );
145 if ( $this->readIndex
< 0 ) {
146 $this->readIndex
= $this->masterIndex
; // default
150 final protected function doOperationsInternal( array $ops, array $opts ) {
151 $status = Status
::newGood();
153 $mbe = $this->backends
[$this->masterIndex
]; // convenience
155 // Try to lock those files for the scope of this function...
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
165 // Clear any cache entries (after locks acquired)
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
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()
184 $status->merge( $syncStatus );
186 return $status; // abort
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
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, $opts );
215 wfDebugLog( 'FileOperationReplication',
216 "'{$backend->getName()}' sync replication; paths: " .
217 FormatJson
::encode( $relevantPaths ) );
218 $status->merge( $backend->doOperations( $realOps, $opts ) );
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
;
233 * Check that a set of files are consistent across all internal backends
235 * @param array $paths List of storage paths
238 public function consistencyCheck( array $paths ) {
239 $status = Status
::newGood();
240 if ( $this->syncChecks
== 0 ||
count( $this->backends
) <= 1 ) {
241 return $status; // skip checks
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 );
255 // Check if all clone backends agree with the master...
256 foreach ( $this->backends
as $index => $cBackend ) {
257 if ( $index === $this->masterIndex
) {
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 );
267 if ( $this->syncChecks
& self
::CHECK_SIZE
) {
268 if ( $cStat['size'] != $mStat['size'] ) { // wrong size
269 $status->fatal( 'backend-fail-synced', $path );
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 );
281 if ( $this->syncChecks
& self
::CHECK_SHA1
) {
282 if ( $cBackend->getFileSha1Base36( $cParams ) !== $mSha1 ) { // wrong SHA1
283 $status->fatal( 'backend-fail-synced', $path );
287 } else { // file is not in master
288 if ( $cStat ) { // file should not exist
289 $status->fatal( 'backend-fail-synced', $path );
299 * Check that a set of file paths are usable across all internal backends
301 * @param array $paths List of storage paths
304 public function accessibilityCheck( array $paths ) {
305 $status = Status
::newGood();
306 if ( count( $this->backends
) <= 1 ) {
307 return $status; // skip checks
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 );
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.
326 * @param array $paths List of storage paths
327 * @param string|bool $resyncMode False, True, or "conservative"; see __construct()
330 public function resyncFiles( array $paths, $resyncMode = true ) {
331 $status = Status
::newGood();
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...
344 // Check of all clone backends agree with the master...
345 foreach ( $this->backends
as $index => $cBackend ) {
346 if ( $index === $this->masterIndex
) {
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...
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']
364 $status->fatal( 'backend-fail-synced', $path );
365 continue; // don't rollback data
367 $fsFile = $mBackend->getLocalReference(
368 [ 'src' => $mPath, 'latest' => true ] );
369 $status->merge( $cBackend->quickStore(
370 [ 'src' => $fsFile->getPath(), 'dst' => $cPath ]
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
377 $status->merge( $cBackend->quickDelete( [ 'src' => $cPath ] ) );
386 * Get a list of file storage paths to read or write for a list of operations
388 * @param array $ops Same format as doOperations()
389 * @return array List of storage paths to files (does not include directories)
391 protected function fileStoragePathsForOps( array $ops ) {
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'] ] )
400 $paths[] = $op['src'];
403 if ( isset( $op['srcs'] ) ) {
404 $paths = array_merge( $paths, $op['srcs'] );
406 if ( isset( $op['dst'] ) ) {
407 $paths[] = $op['dst'];
411 return array_values( array_unique( array_filter( $paths, 'FileBackend::isStoragePath' ) ) );
415 * Substitute the backend name in storage path parameters
416 * for a set of operations with that of a given internal backend.
418 * @param array $ops List of file operation arrays
419 * @param FileBackendStore $backend
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 );
438 * Same as substOpBatchPaths() but for a single operation
440 * @param array $ops File operation array
441 * @param FileBackendStore $backend
444 protected function substOpPaths( array $ops, FileBackendStore
$backend ) {
445 $newOps = $this->substOpBatchPaths( [ $ops ], $backend );
451 * Substitute the backend of storage paths with an internal backend's name
453 * @param array|string $paths List of paths or single string path
454 * @param FileBackendStore $backend
455 * @return array|string
457 protected function substPaths( $paths, FileBackendStore
$backend ) {
459 '!^mwstore://' . preg_quote( $this->name
, '!' ) . '/!',
460 StringUtils
::escapeRegexReplacement( "mwstore://{$backend->getName()}/" ),
461 $paths // string or array
466 * Substitute the backend of internal storage paths with the proxy backend's name
468 * @param array|string $paths List of paths or single string path
469 * @return array|string
471 protected function unsubstPaths( $paths ) {
473 '!^mwstore://([^/]+)!',
474 StringUtils
::escapeRegexReplacement( "mwstore://{$this->name}" ),
475 $paths // string or array
480 * @param array $ops File operations for FileBackend::doOperations()
481 * @return bool Whether there are file path sources with outside lifetime/ownership
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()
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
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 );
513 $status->merge( $backend->doQuickOperations( $realOps ) );
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
;
526 protected function doPrepare( array $params ) {
527 return $this->doDirectoryOp( 'prepare', $params );
530 protected function doSecure( array $params ) {
531 return $this->doDirectoryOp( 'secure', $params );
534 protected function doPublish( array $params ) {
535 return $this->doDirectoryOp( 'publish', $params );
538 protected function doClean( array $params ) {
539 return $this->doDirectoryOp( 'clean', $params );
543 * @param string $method One of (doPrepare,doSecure,doPublish,doClean)
544 * @param array $params Method arguments
547 protected function doDirectoryOp( $method, array $params ) {
548 $status = Status
::newGood();
550 $realParams = $this->substOpPaths( $params, $this->backends
[$this->masterIndex
] );
551 $masterStatus = $this->backends
[$this->masterIndex
]->$method( $realParams );
552 $status->merge( $masterStatus );
554 foreach ( $this->backends
as $index => $backend ) {
555 if ( $index === $this->masterIndex
) {
556 continue; // already done
559 $realParams = $this->substOpPaths( $params, $backend );
560 if ( $this->asyncWrites
) {
561 DeferredUpdates
::addCallableUpdate(
562 function() use ( $backend, $method, $realParams ) {
563 $backend->$method( $realParams );
567 $status->merge( $backend->$method( $realParams ) );
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] );
579 return $this->backends
[$index]->concatenate( $realParams );
582 public function fileExists( array $params ) {
583 $index = $this->getReadIndexFromParams( $params );
584 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
586 return $this->backends
[$index]->fileExists( $realParams );
589 public function getFileTimestamp( array $params ) {
590 $index = $this->getReadIndexFromParams( $params );
591 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
593 return $this->backends
[$index]->getFileTimestamp( $realParams );
596 public function getFileSize( array $params ) {
597 $index = $this->getReadIndexFromParams( $params );
598 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
600 return $this->backends
[$index]->getFileSize( $realParams );
603 public function getFileStat( array $params ) {
604 $index = $this->getReadIndexFromParams( $params );
605 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
607 return $this->backends
[$index]->getFileStat( $realParams );
610 public function getFileXAttributes( array $params ) {
611 $index = $this->getReadIndexFromParams( $params );
612 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
614 return $this->backends
[$index]->getFileXAttributes( $realParams );
617 public function getFileContentsMulti( array $params ) {
618 $index = $this->getReadIndexFromParams( $params );
619 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
621 $contentsM = $this->backends
[$index]->getFileContentsMulti( $realParams );
623 $contents = []; // (path => FSFile) mapping using the proxy backend's name
624 foreach ( $contentsM as $path => $data ) {
625 $contents[$this->unsubstPaths( $path )] = $data;
631 public function getFileSha1Base36( array $params ) {
632 $index = $this->getReadIndexFromParams( $params );
633 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
635 return $this->backends
[$index]->getFileSha1Base36( $realParams );
638 public function getFileProps( array $params ) {
639 $index = $this->getReadIndexFromParams( $params );
640 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
642 return $this->backends
[$index]->getFileProps( $realParams );
645 public function streamFile( array $params ) {
646 $index = $this->getReadIndexFromParams( $params );
647 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
649 return $this->backends
[$index]->streamFile( $realParams );
652 public function getLocalReferenceMulti( array $params ) {
653 $index = $this->getReadIndexFromParams( $params );
654 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
656 $fsFilesM = $this->backends
[$index]->getLocalReferenceMulti( $realParams );
658 $fsFiles = []; // (path => FSFile) mapping using the proxy backend's name
659 foreach ( $fsFilesM as $path => $fsFile ) {
660 $fsFiles[$this->unsubstPaths( $path )] = $fsFile;
666 public function getLocalCopyMulti( array $params ) {
667 $index = $this->getReadIndexFromParams( $params );
668 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
670 $tempFilesM = $this->backends
[$index]->getLocalCopyMulti( $realParams );
672 $tempFiles = []; // (path => TempFSFile) mapping using the proxy backend's name
673 foreach ( $tempFilesM as $path => $tempFile ) {
674 $tempFiles[$this->unsubstPaths( $path )] = $tempFile;
680 public function getFileHttpUrl( array $params ) {
681 $index = $this->getReadIndexFromParams( $params );
682 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
684 return $this->backends
[$index]->getFileHttpUrl( $realParams );
687 public function directoryExists( array $params ) {
688 $realParams = $this->substOpPaths( $params, $this->backends
[$this->masterIndex
] );
690 return $this->backends
[$this->masterIndex
]->directoryExists( $realParams );
693 public function getDirectoryList( array $params ) {
694 $realParams = $this->substOpPaths( $params, $this->backends
[$this->masterIndex
] );
696 return $this->backends
[$this->masterIndex
]->getDirectoryList( $realParams );
699 public function getFileList( array $params ) {
700 $realParams = $this->substOpPaths( $params, $this->backends
[$this->masterIndex
] );
702 return $this->backends
[$this->masterIndex
]->getFileList( $realParams );
705 public function getFeatures() {
706 return $this->backends
[$this->masterIndex
]->getFeatures();
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 );
716 public function preloadCache( array $paths ) {
717 $realPaths = $this->substPaths( $paths, $this->backends
[$this->readIndex
] );
718 $this->backends
[$this->readIndex
]->preloadCache( $realPaths );
721 public function preloadFileStat( array $params ) {
722 $index = $this->getReadIndexFromParams( $params );
723 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
725 return $this->backends
[$index]->preloadFileStat( $realParams );
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
735 LockManager
::LOCK_UW
=> $this->unsubstPaths( $paths[LockManager
::LOCK_UW
] ),
736 LockManager
::LOCK_EX
=> $this->unsubstPaths( $paths[LockManager
::LOCK_EX
] )
739 // Actually acquire the locks
740 return $this->getScopedFileLocks( $pbPaths, 'mixed', $status );
744 * @param array $params
745 * @return int The master or read affinity backend index, based on $params['latest']
747 protected function getReadIndexFromParams( array $params ) {
748 return !empty( $params['latest'] ) ?
$this->masterIndex
: $this->readIndex
;