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 ||
!$this->resyncFiles( $relevantPaths )->isOK() ) {
182 $status->merge( $syncStatus );
184 return $status; // abort
187 // Actually attempt the operation batch on the master backend...
188 $realOps = $this->substOpBatchPaths( $ops, $mbe );
189 $masterStatus = $mbe->doOperations( $realOps, $opts );
190 $status->merge( $masterStatus );
191 // Propagate the operations to the clone backends if there were no unexpected errors
192 // and if there were either no expected errors or if the 'force' option was used.
193 // However, if nothing succeeded at all, then don't replicate any of the operations.
194 // If $ops only had one operation, this might avoid backend sync inconsistencies.
195 if ( $masterStatus->isOK() && $masterStatus->successCount
> 0 ) {
196 foreach ( $this->backends
as $index => $backend ) {
197 if ( $index === $this->masterIndex
) {
198 continue; // done already
201 $realOps = $this->substOpBatchPaths( $ops, $backend );
202 if ( $this->asyncWrites
&& !$this->hasVolatileSources( $ops ) ) {
203 // Bind $scopeLock to the callback to preserve locks
204 DeferredUpdates
::addCallableUpdate(
205 function() use ( $backend, $realOps, $opts, $scopeLock, $relevantPaths ) {
206 wfDebugLog( 'FileOperationReplication',
207 "'{$backend->getName()}' async replication; paths: " .
208 FormatJson
::encode( $relevantPaths ) );
209 $backend->doOperations( $realOps, $opts );
213 wfDebugLog( 'FileOperationReplication',
214 "'{$backend->getName()}' sync replication; paths: " .
215 FormatJson
::encode( $relevantPaths ) );
216 $status->merge( $backend->doOperations( $realOps, $opts ) );
220 // Make 'success', 'successCount', and 'failCount' fields reflect
221 // the overall operation, rather than all the batches for each backend.
222 // Do this by only using success values from the master backend's batch.
223 $status->success
= $masterStatus->success
;
224 $status->successCount
= $masterStatus->successCount
;
225 $status->failCount
= $masterStatus->failCount
;
231 * Check that a set of files are consistent across all internal backends
233 * @param array $paths List of storage paths
236 public function consistencyCheck( array $paths ) {
237 $status = Status
::newGood();
238 if ( $this->syncChecks
== 0 ||
count( $this->backends
) <= 1 ) {
239 return $status; // skip checks
242 $mBackend = $this->backends
[$this->masterIndex
];
243 foreach ( $paths as $path ) {
244 $params = [ 'src' => $path, 'latest' => true ];
245 $mParams = $this->substOpPaths( $params, $mBackend );
246 // Stat the file on the 'master' backend
247 $mStat = $mBackend->getFileStat( $mParams );
248 if ( $this->syncChecks
& self
::CHECK_SHA1
) {
249 $mSha1 = $mBackend->getFileSha1Base36( $mParams );
253 // Check if all clone backends agree with the master...
254 foreach ( $this->backends
as $index => $cBackend ) {
255 if ( $index === $this->masterIndex
) {
258 $cParams = $this->substOpPaths( $params, $cBackend );
259 $cStat = $cBackend->getFileStat( $cParams );
260 if ( $mStat ) { // file is in master
261 if ( !$cStat ) { // file should exist
262 $status->fatal( 'backend-fail-synced', $path );
265 if ( $this->syncChecks
& self
::CHECK_SIZE
) {
266 if ( $cStat['size'] != $mStat['size'] ) { // wrong size
267 $status->fatal( 'backend-fail-synced', $path );
271 if ( $this->syncChecks
& self
::CHECK_TIME
) {
272 $mTs = wfTimestamp( TS_UNIX
, $mStat['mtime'] );
273 $cTs = wfTimestamp( TS_UNIX
, $cStat['mtime'] );
274 if ( abs( $mTs - $cTs ) > 30 ) { // outdated file somewhere
275 $status->fatal( 'backend-fail-synced', $path );
279 if ( $this->syncChecks
& self
::CHECK_SHA1
) {
280 if ( $cBackend->getFileSha1Base36( $cParams ) !== $mSha1 ) { // wrong SHA1
281 $status->fatal( 'backend-fail-synced', $path );
285 } else { // file is not in master
286 if ( $cStat ) { // file should not exist
287 $status->fatal( 'backend-fail-synced', $path );
297 * Check that a set of file paths are usable across all internal backends
299 * @param array $paths List of storage paths
302 public function accessibilityCheck( array $paths ) {
303 $status = Status
::newGood();
304 if ( count( $this->backends
) <= 1 ) {
305 return $status; // skip checks
308 foreach ( $paths as $path ) {
309 foreach ( $this->backends
as $backend ) {
310 $realPath = $this->substPaths( $path, $backend );
311 if ( !$backend->isPathUsableInternal( $realPath ) ) {
312 $status->fatal( 'backend-fail-usable', $path );
321 * Check that a set of files are consistent across all internal backends
322 * and re-synchronize those files against the "multi master" if needed.
324 * @param array $paths List of storage paths
327 public function resyncFiles( array $paths ) {
328 $status = Status
::newGood();
330 $mBackend = $this->backends
[$this->masterIndex
];
331 foreach ( $paths as $path ) {
332 $mPath = $this->substPaths( $path, $mBackend );
333 $mSha1 = $mBackend->getFileSha1Base36( [ 'src' => $mPath, 'latest' => true ] );
334 $mStat = $mBackend->getFileStat( [ 'src' => $mPath, 'latest' => true ] );
335 if ( $mStat === null ||
( $mSha1 !== false && !$mStat ) ) { // sanity
336 $status->fatal( 'backend-fail-internal', $this->name
);
337 wfDebugLog( 'FileOperation', __METHOD__
338 . ': File is not available on the master backend' );
339 continue; // file is not available on the master backend...
341 // Check of all clone backends agree with the master...
342 foreach ( $this->backends
as $index => $cBackend ) {
343 if ( $index === $this->masterIndex
) {
346 $cPath = $this->substPaths( $path, $cBackend );
347 $cSha1 = $cBackend->getFileSha1Base36( [ 'src' => $cPath, 'latest' => true ] );
348 $cStat = $cBackend->getFileStat( [ 'src' => $cPath, 'latest' => true ] );
349 if ( $cStat === null ||
( $cSha1 !== false && !$cStat ) ) { // sanity
350 $status->fatal( 'backend-fail-internal', $cBackend->getName() );
351 wfDebugLog( 'FileOperation', __METHOD__
.
352 ': File is not available on the clone backend' );
353 continue; // file is not available on the clone backend...
355 if ( $mSha1 === $cSha1 ) {
356 // already synced; nothing to do
357 } elseif ( $mSha1 !== false ) { // file is in master
358 if ( $this->autoResync
=== 'conservative'
359 && $cStat && $cStat['mtime'] > $mStat['mtime']
361 $status->fatal( 'backend-fail-synced', $path );
362 continue; // don't rollback data
364 $fsFile = $mBackend->getLocalReference(
365 [ 'src' => $mPath, 'latest' => true ] );
366 $status->merge( $cBackend->quickStore(
367 [ 'src' => $fsFile->getPath(), 'dst' => $cPath ]
369 } elseif ( $mStat === false ) { // file is not in master
370 if ( $this->autoResync
=== 'conservative' ) {
371 $status->fatal( 'backend-fail-synced', $path );
372 continue; // don't delete data
374 $status->merge( $cBackend->quickDelete( [ 'src' => $cPath ] ) );
383 * Get a list of file storage paths to read or write for a list of operations
385 * @param array $ops Same format as doOperations()
386 * @return array List of storage paths to files (does not include directories)
388 protected function fileStoragePathsForOps( array $ops ) {
390 foreach ( $ops as $op ) {
391 if ( isset( $op['src'] ) ) {
392 // For things like copy/move/delete with "ignoreMissingSource" and there
393 // is no source file, nothing should happen and there should be no errors.
394 if ( empty( $op['ignoreMissingSource'] )
395 ||
$this->fileExists( [ 'src' => $op['src'] ] )
397 $paths[] = $op['src'];
400 if ( isset( $op['srcs'] ) ) {
401 $paths = array_merge( $paths, $op['srcs'] );
403 if ( isset( $op['dst'] ) ) {
404 $paths[] = $op['dst'];
408 return array_values( array_unique( array_filter( $paths, 'FileBackend::isStoragePath' ) ) );
412 * Substitute the backend name in storage path parameters
413 * for a set of operations with that of a given internal backend.
415 * @param array $ops List of file operation arrays
416 * @param FileBackendStore $backend
419 protected function substOpBatchPaths( array $ops, FileBackendStore
$backend ) {
420 $newOps = []; // operations
421 foreach ( $ops as $op ) {
422 $newOp = $op; // operation
423 foreach ( [ 'src', 'srcs', 'dst', 'dir' ] as $par ) {
424 if ( isset( $newOp[$par] ) ) { // string or array
425 $newOp[$par] = $this->substPaths( $newOp[$par], $backend );
435 * Same as substOpBatchPaths() but for a single operation
437 * @param array $ops File operation array
438 * @param FileBackendStore $backend
441 protected function substOpPaths( array $ops, FileBackendStore
$backend ) {
442 $newOps = $this->substOpBatchPaths( [ $ops ], $backend );
448 * Substitute the backend of storage paths with an internal backend's name
450 * @param array|string $paths List of paths or single string path
451 * @param FileBackendStore $backend
452 * @return array|string
454 protected function substPaths( $paths, FileBackendStore
$backend ) {
456 '!^mwstore://' . preg_quote( $this->name
, '!' ) . '/!',
457 StringUtils
::escapeRegexReplacement( "mwstore://{$backend->getName()}/" ),
458 $paths // string or array
463 * Substitute the backend of internal storage paths with the proxy backend's name
465 * @param array|string $paths List of paths or single string path
466 * @return array|string
468 protected function unsubstPaths( $paths ) {
470 '!^mwstore://([^/]+)!',
471 StringUtils
::escapeRegexReplacement( "mwstore://{$this->name}" ),
472 $paths // string or array
477 * @param array $ops File operations for FileBackend::doOperations()
478 * @return bool Whether there are file path sources with outside lifetime/ownership
480 protected function hasVolatileSources( array $ops ) {
481 foreach ( $ops as $op ) {
482 if ( $op['op'] === 'store' && !isset( $op['srcRef'] ) ) {
483 return true; // source file might be deleted anytime after do*Operations()
490 protected function doQuickOperationsInternal( array $ops ) {
491 $status = Status
::newGood();
492 // Do the operations on the master backend; setting Status fields...
493 $realOps = $this->substOpBatchPaths( $ops, $this->backends
[$this->masterIndex
] );
494 $masterStatus = $this->backends
[$this->masterIndex
]->doQuickOperations( $realOps );
495 $status->merge( $masterStatus );
496 // Propagate the operations to the clone backends...
497 foreach ( $this->backends
as $index => $backend ) {
498 if ( $index === $this->masterIndex
) {
499 continue; // done already
502 $realOps = $this->substOpBatchPaths( $ops, $backend );
503 if ( $this->asyncWrites
&& !$this->hasVolatileSources( $ops ) ) {
504 DeferredUpdates
::addCallableUpdate(
505 function() use ( $backend, $realOps ) {
506 $backend->doQuickOperations( $realOps );
510 $status->merge( $backend->doQuickOperations( $realOps ) );
513 // Make 'success', 'successCount', and 'failCount' fields reflect
514 // the overall operation, rather than all the batches for each backend.
515 // Do this by only using success values from the master backend's batch.
516 $status->success
= $masterStatus->success
;
517 $status->successCount
= $masterStatus->successCount
;
518 $status->failCount
= $masterStatus->failCount
;
523 protected function doPrepare( array $params ) {
524 return $this->doDirectoryOp( 'prepare', $params );
527 protected function doSecure( array $params ) {
528 return $this->doDirectoryOp( 'secure', $params );
531 protected function doPublish( array $params ) {
532 return $this->doDirectoryOp( 'publish', $params );
535 protected function doClean( array $params ) {
536 return $this->doDirectoryOp( 'clean', $params );
540 * @param string $method One of (doPrepare,doSecure,doPublish,doClean)
541 * @param array $params Method arguments
544 protected function doDirectoryOp( $method, array $params ) {
545 $status = Status
::newGood();
547 $realParams = $this->substOpPaths( $params, $this->backends
[$this->masterIndex
] );
548 $masterStatus = $this->backends
[$this->masterIndex
]->$method( $realParams );
549 $status->merge( $masterStatus );
551 foreach ( $this->backends
as $index => $backend ) {
552 if ( $index === $this->masterIndex
) {
553 continue; // already done
556 $realParams = $this->substOpPaths( $params, $backend );
557 if ( $this->asyncWrites
) {
558 DeferredUpdates
::addCallableUpdate(
559 function() use ( $backend, $method, $realParams ) {
560 $backend->$method( $realParams );
564 $status->merge( $backend->$method( $realParams ) );
571 public function concatenate( array $params ) {
572 // We are writing to an FS file, so we don't need to do this per-backend
573 $index = $this->getReadIndexFromParams( $params );
574 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
576 return $this->backends
[$index]->concatenate( $realParams );
579 public function fileExists( array $params ) {
580 $index = $this->getReadIndexFromParams( $params );
581 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
583 return $this->backends
[$index]->fileExists( $realParams );
586 public function getFileTimestamp( array $params ) {
587 $index = $this->getReadIndexFromParams( $params );
588 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
590 return $this->backends
[$index]->getFileTimestamp( $realParams );
593 public function getFileSize( array $params ) {
594 $index = $this->getReadIndexFromParams( $params );
595 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
597 return $this->backends
[$index]->getFileSize( $realParams );
600 public function getFileStat( array $params ) {
601 $index = $this->getReadIndexFromParams( $params );
602 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
604 return $this->backends
[$index]->getFileStat( $realParams );
607 public function getFileXAttributes( array $params ) {
608 $index = $this->getReadIndexFromParams( $params );
609 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
611 return $this->backends
[$index]->getFileXAttributes( $realParams );
614 public function getFileContentsMulti( array $params ) {
615 $index = $this->getReadIndexFromParams( $params );
616 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
618 $contentsM = $this->backends
[$index]->getFileContentsMulti( $realParams );
620 $contents = []; // (path => FSFile) mapping using the proxy backend's name
621 foreach ( $contentsM as $path => $data ) {
622 $contents[$this->unsubstPaths( $path )] = $data;
628 public function getFileSha1Base36( array $params ) {
629 $index = $this->getReadIndexFromParams( $params );
630 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
632 return $this->backends
[$index]->getFileSha1Base36( $realParams );
635 public function getFileProps( array $params ) {
636 $index = $this->getReadIndexFromParams( $params );
637 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
639 return $this->backends
[$index]->getFileProps( $realParams );
642 public function streamFile( array $params ) {
643 $index = $this->getReadIndexFromParams( $params );
644 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
646 return $this->backends
[$index]->streamFile( $realParams );
649 public function getLocalReferenceMulti( array $params ) {
650 $index = $this->getReadIndexFromParams( $params );
651 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
653 $fsFilesM = $this->backends
[$index]->getLocalReferenceMulti( $realParams );
655 $fsFiles = []; // (path => FSFile) mapping using the proxy backend's name
656 foreach ( $fsFilesM as $path => $fsFile ) {
657 $fsFiles[$this->unsubstPaths( $path )] = $fsFile;
663 public function getLocalCopyMulti( array $params ) {
664 $index = $this->getReadIndexFromParams( $params );
665 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
667 $tempFilesM = $this->backends
[$index]->getLocalCopyMulti( $realParams );
669 $tempFiles = []; // (path => TempFSFile) mapping using the proxy backend's name
670 foreach ( $tempFilesM as $path => $tempFile ) {
671 $tempFiles[$this->unsubstPaths( $path )] = $tempFile;
677 public function getFileHttpUrl( array $params ) {
678 $index = $this->getReadIndexFromParams( $params );
679 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
681 return $this->backends
[$index]->getFileHttpUrl( $realParams );
684 public function directoryExists( array $params ) {
685 $realParams = $this->substOpPaths( $params, $this->backends
[$this->masterIndex
] );
687 return $this->backends
[$this->masterIndex
]->directoryExists( $realParams );
690 public function getDirectoryList( array $params ) {
691 $realParams = $this->substOpPaths( $params, $this->backends
[$this->masterIndex
] );
693 return $this->backends
[$this->masterIndex
]->getDirectoryList( $realParams );
696 public function getFileList( array $params ) {
697 $realParams = $this->substOpPaths( $params, $this->backends
[$this->masterIndex
] );
699 return $this->backends
[$this->masterIndex
]->getFileList( $realParams );
702 public function getFeatures() {
703 return $this->backends
[$this->masterIndex
]->getFeatures();
706 public function clearCache( array $paths = null ) {
707 foreach ( $this->backends
as $backend ) {
708 $realPaths = is_array( $paths ) ?
$this->substPaths( $paths, $backend ) : null;
709 $backend->clearCache( $realPaths );
713 public function preloadCache( array $paths ) {
714 $realPaths = $this->substPaths( $paths, $this->backends
[$this->readIndex
] );
715 $this->backends
[$this->readIndex
]->preloadCache( $realPaths );
718 public function preloadFileStat( array $params ) {
719 $index = $this->getReadIndexFromParams( $params );
720 $realParams = $this->substOpPaths( $params, $this->backends
[$index] );
722 return $this->backends
[$index]->preloadFileStat( $realParams );
725 public function getScopedLocksForOps( array $ops, Status
$status ) {
726 $realOps = $this->substOpBatchPaths( $ops, $this->backends
[$this->masterIndex
] );
727 $fileOps = $this->backends
[$this->masterIndex
]->getOperationsInternal( $realOps );
728 // Get the paths to lock from the master backend
729 $paths = $this->backends
[$this->masterIndex
]->getPathsToLockForOpsInternal( $fileOps );
730 // Get the paths under the proxy backend's name
732 LockManager
::LOCK_UW
=> $this->unsubstPaths( $paths[LockManager
::LOCK_UW
] ),
733 LockManager
::LOCK_EX
=> $this->unsubstPaths( $paths[LockManager
::LOCK_EX
] )
736 // Actually acquire the locks
737 return $this->getScopedFileLocks( $pbPaths, 'mixed', $status );
741 * @param array $params
742 * @return int The master or read affinity backend index, based on $params['latest']
744 protected function getReadIndexFromParams( array $params ) {
745 return !empty( $params['latest'] ) ?
$this->masterIndex
: $this->readIndex
;