3 * @defgroup FileBackend File backend
5 * File backend is used to interact with file storage systems,
6 * such as the local file system, NFS, or cloud storage systems.
10 * Base class for all file backends.
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License along
23 * with this program; if not, write to the Free Software Foundation, Inc.,
24 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
25 * http://www.gnu.org/copyleft/gpl.html
28 * @ingroup FileBackend
29 * @author Aaron Schulz
31 use Psr\Log\LoggerAwareInterface
;
32 use Psr\Log\LoggerInterface
;
35 * @brief Base class for all file backend classes (including multi-write backends).
37 * This class defines the methods as abstract that subclasses must implement.
38 * Outside callers can assume that all backends will have these functions.
40 * All "storage paths" are of the format "mwstore://<backend>/<container>/<path>".
41 * The "backend" portion is unique name for the application to refer to a backend, while
42 * the "container" portion is a top-level directory of the backend. The "path" portion
43 * is a relative path that uses UNIX file system (FS) notation, though any particular
44 * backend may not actually be using a local filesystem. Therefore, the relative paths
47 * Backend contents are stored under "domain"-specific container names by default.
48 * A domain is simply a logical umbrella for entities, such as those belonging to a certain
49 * application or portion of a website, for example. A domain can be local or global.
50 * Global (qualified) backends are achieved by configuring the "domain ID" to a constant.
51 * Global domains are simpler, but local domains can be used by choosing a domain ID based on
52 * the current context, such as which language of a website is being used.
54 * For legacy reasons, the FSFileBackend class allows manually setting the paths of
55 * containers to ones that do not respect the "domain ID".
57 * In key/value (object) stores, containers are the only hierarchy (the rest is emulated).
58 * FS-based backends are somewhat more restrictive due to the existence of real
59 * directory files; a regular file cannot have the same name as a directory. Other
60 * backends with virtual directories may not have this limitation. Callers should
61 * store files in such a way that no files and directories are under the same path.
63 * In general, this class allows for callers to access storage through the same
64 * interface, without regard to the underlying storage system. However, calling code
65 * must follow certain patterns and be aware of certain things to ensure compatibility:
66 * - a) Always call prepare() on the parent directory before trying to put a file there;
67 * key/value stores only need the container to exist first, but filesystems need
68 * all the parent directories to exist first (prepare() is aware of all this)
69 * - b) Always call clean() on a directory when it might become empty to avoid empty
70 * directory buildup on filesystems; key/value stores never have empty directories,
71 * so doing this helps preserve consistency in both cases
72 * - c) Likewise, do not rely on the existence of empty directories for anything;
73 * calling directoryExists() on a path that prepare() was previously called on
74 * will return false for key/value stores if there are no files under that path
75 * - d) Never alter the resulting FSFile returned from getLocalReference(), as it could
76 * either be a copy of the source file in /tmp or the original source file itself
77 * - e) Use a file layout that results in never attempting to store files over directories
78 * or directories over files; key/value stores allow this but filesystems do not
79 * - f) Use ASCII file names (e.g. base32, IDs, hashes) to avoid Unicode issues in Windows
80 * - g) Do not assume that move operations are atomic (difficult with key/value stores)
81 * - h) Do not assume that file stat or read operations always have immediate consistency;
82 * various methods have a "latest" flag that should always be used if up-to-date
83 * information is required (this trades performance for correctness as needed)
84 * - i) Do not assume that directory listings have immediate consistency
86 * Methods of subclasses should avoid throwing exceptions at all costs.
87 * As a corollary, external dependencies should be kept to a minimum.
89 * @ingroup FileBackend
92 abstract class FileBackend
implements LoggerAwareInterface
{
93 /** @var string Unique backend name */
96 /** @var string Unique domain name */
99 /** @var string Read-only explanation message */
102 /** @var string When to do operations in parallel */
103 protected $parallelize;
105 /** @var int How many operations can be done in parallel */
106 protected $concurrency;
108 /** @var string Temporary file directory */
109 protected $tmpDirectory;
111 /** @var LockManager */
112 protected $lockManager;
113 /** @var FileJournal */
114 protected $fileJournal;
115 /** @var LoggerInterface */
117 /** @var object|string Class name or object With profileIn/profileOut methods */
121 protected $statusWrapper;
123 /** Bitfield flags for supported features */
124 const ATTR_HEADERS
= 1; // files can be tagged with standard HTTP headers
125 const ATTR_METADATA
= 2; // files can be stored with metadata key/values
126 const ATTR_UNICODE_PATHS
= 4; // files can have Unicode paths (not just ASCII)
129 * Create a new backend instance from configuration.
130 * This should only be called from within FileBackendGroup.
132 * @param array $config Parameters include:
133 * - name : The unique name of this backend.
134 * This should consist of alphanumberic, '-', and '_' characters.
135 * This name should not be changed after use (e.g. with journaling).
136 * Note that the name is *not* used in actual container names.
137 * - domainId : Prefix to container names that is unique to this backend.
138 * It should only consist of alphanumberic, '-', and '_' characters.
139 * This ID is what avoids collisions if multiple logical backends
140 * use the same storage system, so this should be set carefully.
141 * - lockManager : LockManager object to use for any file locking.
142 * If not provided, then no file locking will be enforced.
143 * - fileJournal : FileJournal object to use for logging changes to files.
144 * If not provided, then change journaling will be disabled.
145 * - readOnly : Write operations are disallowed if this is a non-empty string.
146 * It should be an explanation for the backend being read-only.
147 * - parallelize : When to do file operations in parallel (when possible).
148 * Allowed values are "implicit", "explicit" and "off".
149 * - concurrency : How many file operations can be done in parallel.
150 * - tmpDirectory : Directory to use for temporary files. If this is not set or null,
151 * then the backend will try to discover a usable temporary directory.
152 * - logger : Optional PSR logger object.
153 * - profiler : Optional class name or object With profileIn/profileOut methods.
154 * @throws InvalidArgumentException
156 public function __construct( array $config ) {
157 $this->name
= $config['name'];
158 $this->domainId
= isset( $config['domainId'] )
159 ?
$config['domainId'] // e.g. "my_wiki-en_"
160 : $config['wikiId']; // b/c alias
161 if ( !preg_match( '!^[a-zA-Z0-9-_]{1,255}$!', $this->name
) ) {
162 throw new InvalidArgumentException( "Backend name '{$this->name}' is invalid." );
163 } elseif ( !is_string( $this->domainId
) ) {
164 throw new InvalidArgumentException(
165 "Backend domain ID not provided for '{$this->name}'." );
167 $this->lockManager
= isset( $config['lockManager'] )
168 ?
$config['lockManager']
169 : new NullLockManager( [] );
170 $this->fileJournal
= isset( $config['fileJournal'] )
171 ?
$config['fileJournal']
172 : FileJournal
::factory( [ 'class' => 'NullFileJournal' ], $this->name
);
173 $this->readOnly
= isset( $config['readOnly'] )
174 ?
(string)$config['readOnly']
176 $this->parallelize
= isset( $config['parallelize'] )
177 ?
(string)$config['parallelize']
179 $this->concurrency
= isset( $config['concurrency'] )
180 ?
(int)$config['concurrency']
182 $this->profiler
= isset( $params['profiler'] ) ?
$params['profiler'] : null;
183 $this->logger
= isset( $config['logger'] ) ?
$config['logger'] : new \Psr\Log\
NullLogger();
184 $this->statusWrapper
= isset( $config['statusWrapper'] ) ?
$config['statusWrapper'] : null;
185 $this->tmpDirectory
= isset( $config['tmpDirectory'] ) ?
$config['tmpDirectory'] : null;
188 public function setLogger( LoggerInterface
$logger ) {
189 $this->logger
= $logger;
193 * Get the unique backend name.
194 * We may have multiple different backends of the same type.
195 * For example, we can have two Swift backends using different proxies.
199 final public function getName() {
204 * Get the domain identifier used for this backend (possibly empty).
209 final public function getDomainId() {
210 return $this->domainId
;
214 * Alias to getDomainId()
218 final public function getWikiId() {
219 return $this->getDomainId();
223 * Check if this backend is read-only
227 final public function isReadOnly() {
228 return ( $this->readOnly
!= '' );
232 * Get an explanatory message if this backend is read-only
234 * @return string|bool Returns false if the backend is not read-only
236 final public function getReadOnlyReason() {
237 return ( $this->readOnly
!= '' ) ?
$this->readOnly
: false;
241 * Get the a bitfield of extra features supported by the backend medium
243 * @return int Bitfield of FileBackend::ATTR_* flags
246 public function getFeatures() {
247 return self
::ATTR_UNICODE_PATHS
;
251 * Check if the backend medium supports a field of extra features
253 * @param int $bitfield Bitfield of FileBackend::ATTR_* flags
257 final public function hasFeatures( $bitfield ) {
258 return ( $this->getFeatures() & $bitfield ) === $bitfield;
262 * This is the main entry point into the backend for write operations.
263 * Callers supply an ordered list of operations to perform as a transaction.
264 * Files will be locked, the stat cache cleared, and then the operations attempted.
265 * If any serious errors occur, all attempted operations will be rolled back.
267 * $ops is an array of arrays. The outer array holds a list of operations.
268 * Each inner array is a set of key value pairs that specify an operation.
270 * Supported operations and their parameters. The supported actions are:
276 * - describe (since 1.21)
279 * FSFile/TempFSFile object support was added in 1.27.
281 * a) Create a new file in storage with the contents of a string
285 * 'dst' => <storage path>,
286 * 'content' => <string of new file contents>,
287 * 'overwrite' => <boolean>,
288 * 'overwriteSame' => <boolean>,
289 * 'headers' => <HTTP header name/value map> # since 1.21
293 * b) Copy a file system file into storage
297 * 'src' => <file system path, FSFile, or TempFSFile>,
298 * 'dst' => <storage path>,
299 * 'overwrite' => <boolean>,
300 * 'overwriteSame' => <boolean>,
301 * 'headers' => <HTTP header name/value map> # since 1.21
305 * c) Copy a file within storage
309 * 'src' => <storage path>,
310 * 'dst' => <storage path>,
311 * 'overwrite' => <boolean>,
312 * 'overwriteSame' => <boolean>,
313 * 'ignoreMissingSource' => <boolean>, # since 1.21
314 * 'headers' => <HTTP header name/value map> # since 1.21
318 * d) Move a file within storage
322 * 'src' => <storage path>,
323 * 'dst' => <storage path>,
324 * 'overwrite' => <boolean>,
325 * 'overwriteSame' => <boolean>,
326 * 'ignoreMissingSource' => <boolean>, # since 1.21
327 * 'headers' => <HTTP header name/value map> # since 1.21
331 * e) Delete a file within storage
335 * 'src' => <storage path>,
336 * 'ignoreMissingSource' => <boolean>
340 * f) Update metadata for a file within storage
343 * 'op' => 'describe',
344 * 'src' => <storage path>,
345 * 'headers' => <HTTP header name/value map>
349 * g) Do nothing (no-op)
356 * Boolean flags for operations (operation-specific):
357 * - ignoreMissingSource : The operation will simply succeed and do
358 * nothing if the source file does not exist.
359 * - overwrite : Any destination file will be overwritten.
360 * - overwriteSame : If a file already exists at the destination with the
361 * same contents, then do nothing to the destination file
362 * instead of giving an error. This does not compare headers.
363 * This option is ignored if 'overwrite' is already provided.
364 * - headers : If supplied, the result of merging these headers with any
365 * existing source file headers (replacing conflicting ones)
366 * will be set as the destination file headers. Headers are
367 * deleted if their value is set to the empty string. When a
368 * file has headers they are included in responses to GET and
369 * HEAD requests to the backing store for that file.
370 * Header values should be no larger than 255 bytes, except for
371 * Content-Disposition. The system might ignore or truncate any
372 * headers that are too long to store (exact limits will vary).
373 * Backends that don't support metadata ignore this. (since 1.21)
375 * $opts is an associative of boolean flags, including:
376 * - force : Operation precondition errors no longer trigger an abort.
377 * Any remaining operations are still attempted. Unexpected
378 * failures may still cause remaining operations to be aborted.
379 * - nonLocking : No locks are acquired for the operations.
380 * This can increase performance for non-critical writes.
381 * This has no effect unless the 'force' flag is set.
382 * - nonJournaled : Don't log this operation batch in the file journal.
383 * This limits the ability of recovery scripts.
384 * - parallelize : Try to do operations in parallel when possible.
385 * - bypassReadOnly : Allow writes in read-only mode. (since 1.20)
386 * - preserveCache : Don't clear the process cache before checking files.
387 * This should only be used if all entries in the process
388 * cache were added after the files were already locked. (since 1.20)
390 * @remarks Remarks on locking:
391 * File system paths given to operations should refer to files that are
392 * already locked or otherwise safe from modification from other processes.
393 * Normally these files will be new temp files, which should be adequate.
397 * This returns a Status, which contains all warnings and fatals that occurred
398 * during the operation. The 'failCount', 'successCount', and 'success' members
399 * will reflect each operation attempted.
401 * The StatusValue will be "OK" unless:
402 * - a) unexpected operation errors occurred (network partitions, disk full...)
403 * - b) significant operation errors occurred and 'force' was not set
405 * @param array $ops List of operations to execute in order
406 * @param array $opts Batch operation options
407 * @return StatusValue
409 final public function doOperations( array $ops, array $opts = [] ) {
410 if ( empty( $opts['bypassReadOnly'] ) && $this->isReadOnly() ) {
411 return $this->newStatus( 'backend-fail-readonly', $this->name
, $this->readOnly
);
413 if ( !count( $ops ) ) {
414 return $this->newStatus(); // nothing to do
417 $ops = $this->resolveFSFileObjects( $ops );
418 if ( empty( $opts['force'] ) ) { // sanity
419 unset( $opts['nonLocking'] );
422 /** @noinspection PhpUnusedLocalVariableInspection */
423 $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts
425 return $this->doOperationsInternal( $ops, $opts );
429 * @see FileBackend::doOperations()
433 abstract protected function doOperationsInternal( array $ops, array $opts );
436 * Same as doOperations() except it takes a single operation.
437 * If you are doing a batch of operations that should either
438 * all succeed or all fail, then use that function instead.
440 * @see FileBackend::doOperations()
442 * @param array $op Operation
443 * @param array $opts Operation options
444 * @return StatusValue
446 final public function doOperation( array $op, array $opts = [] ) {
447 return $this->doOperations( [ $op ], $opts );
451 * Performs a single create operation.
452 * This sets $params['op'] to 'create' and passes it to doOperation().
454 * @see FileBackend::doOperation()
456 * @param array $params Operation parameters
457 * @param array $opts Operation options
458 * @return StatusValue
460 final public function create( array $params, array $opts = [] ) {
461 return $this->doOperation( [ 'op' => 'create' ] +
$params, $opts );
465 * Performs a single store operation.
466 * This sets $params['op'] to 'store' and passes it to doOperation().
468 * @see FileBackend::doOperation()
470 * @param array $params Operation parameters
471 * @param array $opts Operation options
472 * @return StatusValue
474 final public function store( array $params, array $opts = [] ) {
475 return $this->doOperation( [ 'op' => 'store' ] +
$params, $opts );
479 * Performs a single copy operation.
480 * This sets $params['op'] to 'copy' and passes it to doOperation().
482 * @see FileBackend::doOperation()
484 * @param array $params Operation parameters
485 * @param array $opts Operation options
486 * @return StatusValue
488 final public function copy( array $params, array $opts = [] ) {
489 return $this->doOperation( [ 'op' => 'copy' ] +
$params, $opts );
493 * Performs a single move operation.
494 * This sets $params['op'] to 'move' and passes it to doOperation().
496 * @see FileBackend::doOperation()
498 * @param array $params Operation parameters
499 * @param array $opts Operation options
500 * @return StatusValue
502 final public function move( array $params, array $opts = [] ) {
503 return $this->doOperation( [ 'op' => 'move' ] +
$params, $opts );
507 * Performs a single delete operation.
508 * This sets $params['op'] to 'delete' and passes it to doOperation().
510 * @see FileBackend::doOperation()
512 * @param array $params Operation parameters
513 * @param array $opts Operation options
514 * @return StatusValue
516 final public function delete( array $params, array $opts = [] ) {
517 return $this->doOperation( [ 'op' => 'delete' ] +
$params, $opts );
521 * Performs a single describe operation.
522 * This sets $params['op'] to 'describe' and passes it to doOperation().
524 * @see FileBackend::doOperation()
526 * @param array $params Operation parameters
527 * @param array $opts Operation options
528 * @return StatusValue
531 final public function describe( array $params, array $opts = [] ) {
532 return $this->doOperation( [ 'op' => 'describe' ] +
$params, $opts );
536 * Perform a set of independent file operations on some files.
538 * This does no locking, nor journaling, and possibly no stat calls.
539 * Any destination files that already exist will be overwritten.
540 * This should *only* be used on non-original files, like cache files.
542 * Supported operations and their parameters:
548 * - describe (since 1.21)
551 * FSFile/TempFSFile object support was added in 1.27.
553 * a) Create a new file in storage with the contents of a string
557 * 'dst' => <storage path>,
558 * 'content' => <string of new file contents>,
559 * 'headers' => <HTTP header name/value map> # since 1.21
563 * b) Copy a file system file into storage
567 * 'src' => <file system path, FSFile, or TempFSFile>,
568 * 'dst' => <storage path>,
569 * 'headers' => <HTTP header name/value map> # since 1.21
573 * c) Copy a file within storage
577 * 'src' => <storage path>,
578 * 'dst' => <storage path>,
579 * 'ignoreMissingSource' => <boolean>, # since 1.21
580 * 'headers' => <HTTP header name/value map> # since 1.21
584 * d) Move a file within storage
588 * 'src' => <storage path>,
589 * 'dst' => <storage path>,
590 * 'ignoreMissingSource' => <boolean>, # since 1.21
591 * 'headers' => <HTTP header name/value map> # since 1.21
595 * e) Delete a file within storage
599 * 'src' => <storage path>,
600 * 'ignoreMissingSource' => <boolean>
604 * f) Update metadata for a file within storage
607 * 'op' => 'describe',
608 * 'src' => <storage path>,
609 * 'headers' => <HTTP header name/value map>
613 * g) Do nothing (no-op)
620 * @par Boolean flags for operations (operation-specific):
621 * - ignoreMissingSource : The operation will simply succeed and do
622 * nothing if the source file does not exist.
623 * - headers : If supplied with a header name/value map, the backend will
624 * reply with these headers when GETs/HEADs of the destination
625 * file are made. Header values should be smaller than 256 bytes.
626 * Content-Disposition headers can be longer, though the system
627 * might ignore or truncate ones that are too long to store.
628 * Existing headers will remain, but these will replace any
629 * conflicting previous headers, and headers will be removed
630 * if they are set to an empty string.
631 * Backends that don't support metadata ignore this. (since 1.21)
633 * $opts is an associative of boolean flags, including:
634 * - bypassReadOnly : Allow writes in read-only mode (since 1.20)
637 * This returns a Status, which contains all warnings and fatals that occurred
638 * during the operation. The 'failCount', 'successCount', and 'success' members
639 * will reflect each operation attempted for the given files. The StatusValue will be
640 * considered "OK" as long as no fatal errors occurred.
642 * @param array $ops Set of operations to execute
643 * @param array $opts Batch operation options
644 * @return StatusValue
647 final public function doQuickOperations( array $ops, array $opts = [] ) {
648 if ( empty( $opts['bypassReadOnly'] ) && $this->isReadOnly() ) {
649 return $this->newStatus( 'backend-fail-readonly', $this->name
, $this->readOnly
);
651 if ( !count( $ops ) ) {
652 return $this->newStatus(); // nothing to do
655 $ops = $this->resolveFSFileObjects( $ops );
656 foreach ( $ops as &$op ) {
657 $op['overwrite'] = true; // avoids RTTs in key/value stores
660 /** @noinspection PhpUnusedLocalVariableInspection */
661 $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts
663 return $this->doQuickOperationsInternal( $ops );
667 * @see FileBackend::doQuickOperations()
671 abstract protected function doQuickOperationsInternal( array $ops );
674 * Same as doQuickOperations() except it takes a single operation.
675 * If you are doing a batch of operations, then use that function instead.
677 * @see FileBackend::doQuickOperations()
679 * @param array $op Operation
680 * @return StatusValue
683 final public function doQuickOperation( array $op ) {
684 return $this->doQuickOperations( [ $op ] );
688 * Performs a single quick create operation.
689 * This sets $params['op'] to 'create' and passes it to doQuickOperation().
691 * @see FileBackend::doQuickOperation()
693 * @param array $params Operation parameters
694 * @return StatusValue
697 final public function quickCreate( array $params ) {
698 return $this->doQuickOperation( [ 'op' => 'create' ] +
$params );
702 * Performs a single quick store operation.
703 * This sets $params['op'] to 'store' and passes it to doQuickOperation().
705 * @see FileBackend::doQuickOperation()
707 * @param array $params Operation parameters
708 * @return StatusValue
711 final public function quickStore( array $params ) {
712 return $this->doQuickOperation( [ 'op' => 'store' ] +
$params );
716 * Performs a single quick copy operation.
717 * This sets $params['op'] to 'copy' and passes it to doQuickOperation().
719 * @see FileBackend::doQuickOperation()
721 * @param array $params Operation parameters
722 * @return StatusValue
725 final public function quickCopy( array $params ) {
726 return $this->doQuickOperation( [ 'op' => 'copy' ] +
$params );
730 * Performs a single quick move operation.
731 * This sets $params['op'] to 'move' and passes it to doQuickOperation().
733 * @see FileBackend::doQuickOperation()
735 * @param array $params Operation parameters
736 * @return StatusValue
739 final public function quickMove( array $params ) {
740 return $this->doQuickOperation( [ 'op' => 'move' ] +
$params );
744 * Performs a single quick delete operation.
745 * This sets $params['op'] to 'delete' and passes it to doQuickOperation().
747 * @see FileBackend::doQuickOperation()
749 * @param array $params Operation parameters
750 * @return StatusValue
753 final public function quickDelete( array $params ) {
754 return $this->doQuickOperation( [ 'op' => 'delete' ] +
$params );
758 * Performs a single quick describe operation.
759 * This sets $params['op'] to 'describe' and passes it to doQuickOperation().
761 * @see FileBackend::doQuickOperation()
763 * @param array $params Operation parameters
764 * @return StatusValue
767 final public function quickDescribe( array $params ) {
768 return $this->doQuickOperation( [ 'op' => 'describe' ] +
$params );
772 * Concatenate a list of storage files into a single file system file.
773 * The target path should refer to a file that is already locked or
774 * otherwise safe from modification from other processes. Normally,
775 * the file will be a new temp file, which should be adequate.
777 * @param array $params Operation parameters, include:
778 * - srcs : ordered source storage paths (e.g. chunk1, chunk2, ...)
779 * - dst : file system path to 0-byte temp file
780 * - parallelize : try to do operations in parallel when possible
781 * @return StatusValue
783 abstract public function concatenate( array $params );
786 * Prepare a storage directory for usage.
787 * This will create any required containers and parent directories.
788 * Backends using key/value stores only need to create the container.
790 * The 'noAccess' and 'noListing' parameters works the same as in secure(),
791 * except they are only applied *if* the directory/container had to be created.
792 * These flags should always be set for directories that have private files.
793 * However, setting them is not guaranteed to actually do anything.
794 * Additional server configuration may be needed to achieve the desired effect.
796 * @param array $params Parameters include:
797 * - dir : storage directory
798 * - noAccess : try to deny file access (since 1.20)
799 * - noListing : try to deny file listing (since 1.20)
800 * - bypassReadOnly : allow writes in read-only mode (since 1.20)
801 * @return StatusValue
803 final public function prepare( array $params ) {
804 if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
805 return $this->newStatus( 'backend-fail-readonly', $this->name
, $this->readOnly
);
807 /** @noinspection PhpUnusedLocalVariableInspection */
808 $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts
809 return $this->doPrepare( $params );
813 * @see FileBackend::prepare()
814 * @param array $params
816 abstract protected function doPrepare( array $params );
819 * Take measures to block web access to a storage directory and
820 * the container it belongs to. FS backends might add .htaccess
821 * files whereas key/value store backends might revoke container
822 * access to the storage user representing end-users in web requests.
824 * This is not guaranteed to actually make files or listings publically hidden.
825 * Additional server configuration may be needed to achieve the desired effect.
827 * @param array $params Parameters include:
828 * - dir : storage directory
829 * - noAccess : try to deny file access
830 * - noListing : try to deny file listing
831 * - bypassReadOnly : allow writes in read-only mode (since 1.20)
832 * @return StatusValue
834 final public function secure( array $params ) {
835 if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
836 return $this->newStatus( 'backend-fail-readonly', $this->name
, $this->readOnly
);
838 /** @noinspection PhpUnusedLocalVariableInspection */
839 $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts
840 return $this->doSecure( $params );
844 * @see FileBackend::secure()
845 * @param array $params
847 abstract protected function doSecure( array $params );
850 * Remove measures to block web access to a storage directory and
851 * the container it belongs to. FS backends might remove .htaccess
852 * files whereas key/value store backends might grant container
853 * access to the storage user representing end-users in web requests.
854 * This essentially can undo the result of secure() calls.
856 * This is not guaranteed to actually make files or listings publically viewable.
857 * Additional server configuration may be needed to achieve the desired effect.
859 * @param array $params Parameters include:
860 * - dir : storage directory
861 * - access : try to allow file access
862 * - listing : try to allow file listing
863 * - bypassReadOnly : allow writes in read-only mode (since 1.20)
864 * @return StatusValue
867 final public function publish( array $params ) {
868 if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
869 return $this->newStatus( 'backend-fail-readonly', $this->name
, $this->readOnly
);
871 /** @noinspection PhpUnusedLocalVariableInspection */
872 $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts
873 return $this->doPublish( $params );
877 * @see FileBackend::publish()
878 * @param array $params
880 abstract protected function doPublish( array $params );
883 * Delete a storage directory if it is empty.
884 * Backends using key/value stores may do nothing unless the directory
885 * is that of an empty container, in which case it will be deleted.
887 * @param array $params Parameters include:
888 * - dir : storage directory
889 * - recursive : recursively delete empty subdirectories first (since 1.20)
890 * - bypassReadOnly : allow writes in read-only mode (since 1.20)
891 * @return StatusValue
893 final public function clean( array $params ) {
894 if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
895 return $this->newStatus( 'backend-fail-readonly', $this->name
, $this->readOnly
);
897 /** @noinspection PhpUnusedLocalVariableInspection */
898 $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts
899 return $this->doClean( $params );
903 * @see FileBackend::clean()
904 * @param array $params
906 abstract protected function doClean( array $params );
909 * Enter file operation scope.
910 * This just makes PHP ignore user aborts/disconnects until the return
911 * value leaves scope. This returns null and does nothing in CLI mode.
913 * @return ScopedCallback|null
915 final protected function getScopedPHPBehaviorForOps() {
916 if ( PHP_SAPI
!= 'cli' ) { // http://bugs.php.net/bug.php?id=47540
917 $old = ignore_user_abort( true ); // avoid half-finished operations
918 return new ScopedCallback( function () use ( $old ) {
919 ignore_user_abort( $old );
927 * Check if a file exists at a storage path in the backend.
928 * This returns false if only a directory exists at the path.
930 * @param array $params Parameters include:
931 * - src : source storage path
932 * - latest : use the latest available data
933 * @return bool|null Returns null on failure
935 abstract public function fileExists( array $params );
938 * Get the last-modified timestamp of the file at a storage path.
940 * @param array $params Parameters include:
941 * - src : source storage path
942 * - latest : use the latest available data
943 * @return string|bool TS_MW timestamp or false on failure
945 abstract public function getFileTimestamp( array $params );
948 * Get the contents of a file at a storage path in the backend.
949 * This should be avoided for potentially large files.
951 * @param array $params Parameters include:
952 * - src : source storage path
953 * - latest : use the latest available data
954 * @return string|bool Returns false on failure
956 final public function getFileContents( array $params ) {
957 $contents = $this->getFileContentsMulti(
958 [ 'srcs' => [ $params['src'] ] ] +
$params );
960 return $contents[$params['src']];
964 * Like getFileContents() except it takes an array of storage paths
965 * and returns a map of storage paths to strings (or null on failure).
966 * The map keys (paths) are in the same order as the provided list of paths.
968 * @see FileBackend::getFileContents()
970 * @param array $params Parameters include:
971 * - srcs : list of source storage paths
972 * - latest : use the latest available data
973 * - parallelize : try to do operations in parallel when possible
974 * @return array Map of (path name => string or false on failure)
977 abstract public function getFileContentsMulti( array $params );
980 * Get metadata about a file at a storage path in the backend.
981 * If the file does not exist, then this returns false.
982 * Otherwise, the result is an associative array that includes:
983 * - headers : map of HTTP headers used for GET/HEAD requests (name => value)
984 * - metadata : map of file metadata (name => value)
985 * Metadata keys and headers names will be returned in all lower-case.
986 * Additional values may be included for internal use only.
988 * Use FileBackend::hasFeatures() to check how well this is supported.
990 * @param array $params
992 * - src : source storage path
993 * - latest : use the latest available data
994 * @return array|bool Returns false on failure
997 abstract public function getFileXAttributes( array $params );
1000 * Get the size (bytes) of a file at a storage path in the backend.
1002 * @param array $params Parameters include:
1003 * - src : source storage path
1004 * - latest : use the latest available data
1005 * @return int|bool Returns false on failure
1007 abstract public function getFileSize( array $params );
1010 * Get quick information about a file at a storage path in the backend.
1011 * If the file does not exist, then this returns false.
1012 * Otherwise, the result is an associative array that includes:
1013 * - mtime : the last-modified timestamp (TS_MW)
1014 * - size : the file size (bytes)
1015 * Additional values may be included for internal use only.
1017 * @param array $params Parameters include:
1018 * - src : source storage path
1019 * - latest : use the latest available data
1020 * @return array|bool|null Returns null on failure
1022 abstract public function getFileStat( array $params );
1025 * Get a SHA-1 hash of the file at a storage path in the backend.
1027 * @param array $params Parameters include:
1028 * - src : source storage path
1029 * - latest : use the latest available data
1030 * @return string|bool Hash string or false on failure
1032 abstract public function getFileSha1Base36( array $params );
1035 * Get the properties of the file at a storage path in the backend.
1036 * This gives the result of FSFile::getProps() on a local copy of the file.
1038 * @param array $params Parameters include:
1039 * - src : source storage path
1040 * - latest : use the latest available data
1041 * @return array Returns FSFile::placeholderProps() on failure
1043 abstract public function getFileProps( array $params );
1046 * Stream the file at a storage path in the backend.
1048 * If the file does not exists, an HTTP 404 error will be given.
1049 * Appropriate HTTP headers (Status, Content-Type, Content-Length)
1050 * will be sent if streaming began, while none will be sent otherwise.
1051 * Implementations should flush the output buffer before sending data.
1053 * @param array $params Parameters include:
1054 * - src : source storage path
1055 * - headers : list of additional HTTP headers to send if the file exists
1056 * - options : HTTP request header map with lower case keys (since 1.28). Supports:
1057 * range : format is "bytes=(\d*-\d*)"
1058 * if-modified-since : format is an HTTP date
1059 * - headless : only include the body (and headers from "headers") (since 1.28)
1060 * - latest : use the latest available data
1061 * - allowOB : preserve any output buffers (since 1.28)
1062 * @return StatusValue
1064 abstract public function streamFile( array $params );
1067 * Returns a file system file, identical to the file at a storage path.
1068 * The file returned is either:
1069 * - a) A local copy of the file at a storage path in the backend.
1070 * The temporary copy will have the same extension as the source.
1071 * - b) An original of the file at a storage path in the backend.
1072 * Temporary files may be purged when the file object falls out of scope.
1074 * Write operations should *never* be done on this file as some backends
1075 * may do internal tracking or may be instances of FileBackendMultiWrite.
1076 * In that latter case, there are copies of the file that must stay in sync.
1077 * Additionally, further calls to this function may return the same file.
1079 * @param array $params Parameters include:
1080 * - src : source storage path
1081 * - latest : use the latest available data
1082 * @return FSFile|null Returns null on failure
1084 final public function getLocalReference( array $params ) {
1085 $fsFiles = $this->getLocalReferenceMulti(
1086 [ 'srcs' => [ $params['src'] ] ] +
$params );
1088 return $fsFiles[$params['src']];
1092 * Like getLocalReference() except it takes an array of storage paths
1093 * and returns a map of storage paths to FSFile objects (or null on failure).
1094 * The map keys (paths) are in the same order as the provided list of paths.
1096 * @see FileBackend::getLocalReference()
1098 * @param array $params Parameters include:
1099 * - srcs : list of source storage paths
1100 * - latest : use the latest available data
1101 * - parallelize : try to do operations in parallel when possible
1102 * @return array Map of (path name => FSFile or null on failure)
1105 abstract public function getLocalReferenceMulti( array $params );
1108 * Get a local copy on disk of the file at a storage path in the backend.
1109 * The temporary copy will have the same file extension as the source.
1110 * Temporary files may be purged when the file object falls out of scope.
1112 * @param array $params Parameters include:
1113 * - src : source storage path
1114 * - latest : use the latest available data
1115 * @return TempFSFile|null Returns null on failure
1117 final public function getLocalCopy( array $params ) {
1118 $tmpFiles = $this->getLocalCopyMulti(
1119 [ 'srcs' => [ $params['src'] ] ] +
$params );
1121 return $tmpFiles[$params['src']];
1125 * Like getLocalCopy() except it takes an array of storage paths and
1126 * returns a map of storage paths to TempFSFile objects (or null on failure).
1127 * The map keys (paths) are in the same order as the provided list of paths.
1129 * @see FileBackend::getLocalCopy()
1131 * @param array $params Parameters include:
1132 * - srcs : list of source storage paths
1133 * - latest : use the latest available data
1134 * - parallelize : try to do operations in parallel when possible
1135 * @return array Map of (path name => TempFSFile or null on failure)
1138 abstract public function getLocalCopyMulti( array $params );
1141 * Return an HTTP URL to a given file that requires no authentication to use.
1142 * The URL may be pre-authenticated (via some token in the URL) and temporary.
1143 * This will return null if the backend cannot make an HTTP URL for the file.
1145 * This is useful for key/value stores when using scripts that seek around
1146 * large files and those scripts (and the backend) support HTTP Range headers.
1147 * Otherwise, one would need to use getLocalReference(), which involves loading
1148 * the entire file on to local disk.
1150 * @param array $params Parameters include:
1151 * - src : source storage path
1152 * - ttl : lifetime (seconds) if pre-authenticated; default is 1 day
1153 * @return string|null
1156 abstract public function getFileHttpUrl( array $params );
1159 * Check if a directory exists at a given storage path.
1160 * Backends using key/value stores will check if the path is a
1161 * virtual directory, meaning there are files under the given directory.
1163 * Storage backends with eventual consistency might return stale data.
1165 * @param array $params Parameters include:
1166 * - dir : storage directory
1167 * @return bool|null Returns null on failure
1170 abstract public function directoryExists( array $params );
1173 * Get an iterator to list *all* directories under a storage directory.
1174 * If the directory is of the form "mwstore://backend/container",
1175 * then all directories in the container will be listed.
1176 * If the directory is of form "mwstore://backend/container/dir",
1177 * then all directories directly under that directory will be listed.
1178 * Results will be storage directories relative to the given directory.
1180 * Storage backends with eventual consistency might return stale data.
1182 * Failures during iteration can result in FileBackendError exceptions (since 1.22).
1184 * @param array $params Parameters include:
1185 * - dir : storage directory
1186 * - topOnly : only return direct child dirs of the directory
1187 * @return Traversable|array|null Returns null on failure
1190 abstract public function getDirectoryList( array $params );
1193 * Same as FileBackend::getDirectoryList() except only lists
1194 * directories that are immediately under the given directory.
1196 * Storage backends with eventual consistency might return stale data.
1198 * Failures during iteration can result in FileBackendError exceptions (since 1.22).
1200 * @param array $params Parameters include:
1201 * - dir : storage directory
1202 * @return Traversable|array|null Returns null on failure
1205 final public function getTopDirectoryList( array $params ) {
1206 return $this->getDirectoryList( [ 'topOnly' => true ] +
$params );
1210 * Get an iterator to list *all* stored files under a storage directory.
1211 * If the directory is of the form "mwstore://backend/container",
1212 * then all files in the container will be listed.
1213 * If the directory is of form "mwstore://backend/container/dir",
1214 * then all files under that directory will be listed.
1215 * Results will be storage paths relative to the given directory.
1217 * Storage backends with eventual consistency might return stale data.
1219 * Failures during iteration can result in FileBackendError exceptions (since 1.22).
1221 * @param array $params Parameters include:
1222 * - dir : storage directory
1223 * - topOnly : only return direct child files of the directory (since 1.20)
1224 * - adviseStat : set to true if stat requests will be made on the files (since 1.22)
1225 * @return Traversable|array|null Returns null on failure
1227 abstract public function getFileList( array $params );
1230 * Same as FileBackend::getFileList() except only lists
1231 * files that are immediately under the given directory.
1233 * Storage backends with eventual consistency might return stale data.
1235 * Failures during iteration can result in FileBackendError exceptions (since 1.22).
1237 * @param array $params Parameters include:
1238 * - dir : storage directory
1239 * - adviseStat : set to true if stat requests will be made on the files (since 1.22)
1240 * @return Traversable|array|null Returns null on failure
1243 final public function getTopFileList( array $params ) {
1244 return $this->getFileList( [ 'topOnly' => true ] +
$params );
1248 * Preload persistent file stat cache and property cache into in-process cache.
1249 * This should be used when stat calls will be made on a known list of a many files.
1251 * @see FileBackend::getFileStat()
1253 * @param array $paths Storage paths
1255 abstract public function preloadCache( array $paths );
1258 * Invalidate any in-process file stat and property cache.
1259 * If $paths is given, then only the cache for those files will be cleared.
1261 * @see FileBackend::getFileStat()
1263 * @param array $paths Storage paths (optional)
1265 abstract public function clearCache( array $paths = null );
1268 * Preload file stat information (concurrently if possible) into in-process cache.
1270 * This should be used when stat calls will be made on a known list of a many files.
1271 * This does not make use of the persistent file stat cache.
1273 * @see FileBackend::getFileStat()
1275 * @param array $params Parameters include:
1276 * - srcs : list of source storage paths
1277 * - latest : use the latest available data
1278 * @return bool All requests proceeded without I/O errors (since 1.24)
1281 abstract public function preloadFileStat( array $params );
1284 * Lock the files at the given storage paths in the backend.
1285 * This will either lock all the files or none (on failure).
1287 * Callers should consider using getScopedFileLocks() instead.
1289 * @param array $paths Storage paths
1290 * @param int $type LockManager::LOCK_* constant
1291 * @param int $timeout Timeout in seconds (0 means non-blocking) (since 1.24)
1292 * @return StatusValue
1294 final public function lockFiles( array $paths, $type, $timeout = 0 ) {
1295 $paths = array_map( 'FileBackend::normalizeStoragePath', $paths );
1297 return $this->wrapStatus( $this->lockManager
->lock( $paths, $type, $timeout ) );
1301 * Unlock the files at the given storage paths in the backend.
1303 * @param array $paths Storage paths
1304 * @param int $type LockManager::LOCK_* constant
1305 * @return StatusValue
1307 final public function unlockFiles( array $paths, $type ) {
1308 $paths = array_map( 'FileBackend::normalizeStoragePath', $paths );
1310 return $this->wrapStatus( $this->lockManager
->unlock( $paths, $type ) );
1314 * Lock the files at the given storage paths in the backend.
1315 * This will either lock all the files or none (on failure).
1316 * On failure, the StatusValue object will be updated with errors.
1318 * Once the return value goes out scope, the locks will be released and
1319 * the StatusValue updated. Unlock fatals will not change the StatusValue "OK" value.
1321 * @see ScopedLock::factory()
1323 * @param array $paths List of storage paths or map of lock types to path lists
1324 * @param int|string $type LockManager::LOCK_* constant or "mixed"
1325 * @param StatusValue $status StatusValue to update on lock/unlock
1326 * @param int $timeout Timeout in seconds (0 means non-blocking) (since 1.24)
1327 * @return ScopedLock|null Returns null on failure
1329 final public function getScopedFileLocks(
1330 array $paths, $type, StatusValue
$status, $timeout = 0
1332 if ( $type === 'mixed' ) {
1333 foreach ( $paths as &$typePaths ) {
1334 $typePaths = array_map( 'FileBackend::normalizeStoragePath', $typePaths );
1337 $paths = array_map( 'FileBackend::normalizeStoragePath', $paths );
1340 return ScopedLock
::factory( $this->lockManager
, $paths, $type, $status, $timeout );
1344 * Get an array of scoped locks needed for a batch of file operations.
1346 * Normally, FileBackend::doOperations() handles locking, unless
1347 * the 'nonLocking' param is passed in. This function is useful if you
1348 * want the files to be locked for a broader scope than just when the
1349 * files are changing. For example, if you need to update DB metadata,
1350 * you may want to keep the files locked until finished.
1352 * @see FileBackend::doOperations()
1354 * @param array $ops List of file operations to FileBackend::doOperations()
1355 * @param StatusValue $status StatusValue to update on lock/unlock
1356 * @return ScopedLock|null
1359 abstract public function getScopedLocksForOps( array $ops, StatusValue
$status );
1362 * Get the root storage path of this backend.
1363 * All container paths are "subdirectories" of this path.
1365 * @return string Storage path
1368 final public function getRootStoragePath() {
1369 return "mwstore://{$this->name}";
1373 * Get the storage path for the given container for this backend
1375 * @param string $container Container name
1376 * @return string Storage path
1379 final public function getContainerStoragePath( $container ) {
1380 return $this->getRootStoragePath() . "/{$container}";
1384 * Get the file journal object for this backend
1386 * @return FileJournal
1388 final public function getJournal() {
1389 return $this->fileJournal
;
1393 * Convert FSFile 'src' paths to string paths (with an 'srcRef' field set to the FSFile)
1395 * The 'srcRef' field keeps any TempFSFile objects in scope for the backend to have it
1396 * around as long it needs (which may vary greatly depending on configuration)
1398 * @param array $ops File operation batch for FileBaclend::doOperations()
1399 * @return array File operation batch
1401 protected function resolveFSFileObjects( array $ops ) {
1402 foreach ( $ops as &$op ) {
1403 $src = isset( $op['src'] ) ?
$op['src'] : null;
1404 if ( $src instanceof FSFile
) {
1405 $op['srcRef'] = $src;
1406 $op['src'] = $src->getPath();
1415 * Check if a given path is a "mwstore://" path.
1416 * This does not do any further validation or any existence checks.
1418 * @param string $path
1421 final public static function isStoragePath( $path ) {
1422 return ( strpos( $path, 'mwstore://' ) === 0 );
1426 * Split a storage path into a backend name, a container name,
1427 * and a relative file path. The relative path may be the empty string.
1428 * This does not do any path normalization or traversal checks.
1430 * @param string $storagePath
1431 * @return array (backend, container, rel object) or (null, null, null)
1433 final public static function splitStoragePath( $storagePath ) {
1434 if ( self
::isStoragePath( $storagePath ) ) {
1435 // Remove the "mwstore://" prefix and split the path
1436 $parts = explode( '/', substr( $storagePath, 10 ), 3 );
1437 if ( count( $parts ) >= 2 && $parts[0] != '' && $parts[1] != '' ) {
1438 if ( count( $parts ) == 3 ) {
1439 return $parts; // e.g. "backend/container/path"
1441 return [ $parts[0], $parts[1], '' ]; // e.g. "backend/container"
1446 return [ null, null, null ];
1450 * Normalize a storage path by cleaning up directory separators.
1451 * Returns null if the path is not of the format of a valid storage path.
1453 * @param string $storagePath
1454 * @return string|null
1456 final public static function normalizeStoragePath( $storagePath ) {
1457 list( $backend, $container, $relPath ) = self
::splitStoragePath( $storagePath );
1458 if ( $relPath !== null ) { // must be for this backend
1459 $relPath = self
::normalizeContainerPath( $relPath );
1460 if ( $relPath !== null ) {
1461 return ( $relPath != '' )
1462 ?
"mwstore://{$backend}/{$container}/{$relPath}"
1463 : "mwstore://{$backend}/{$container}";
1471 * Get the parent storage directory of a storage path.
1472 * This returns a path like "mwstore://backend/container",
1473 * "mwstore://backend/container/...", or null if there is no parent.
1475 * @param string $storagePath
1476 * @return string|null
1478 final public static function parentStoragePath( $storagePath ) {
1479 $storagePath = dirname( $storagePath );
1480 list( , , $rel ) = self
::splitStoragePath( $storagePath );
1482 return ( $rel === null ) ?
null : $storagePath;
1486 * Get the final extension from a storage or FS path
1488 * @param string $path
1489 * @param string $case One of (rawcase, uppercase, lowercase) (since 1.24)
1492 final public static function extensionFromPath( $path, $case = 'lowercase' ) {
1493 $i = strrpos( $path, '.' );
1494 $ext = $i ?
substr( $path, $i +
1 ) : '';
1496 if ( $case === 'lowercase' ) {
1497 $ext = strtolower( $ext );
1498 } elseif ( $case === 'uppercase' ) {
1499 $ext = strtoupper( $ext );
1506 * Check if a relative path has no directory traversals
1508 * @param string $path
1512 final public static function isPathTraversalFree( $path ) {
1513 return ( self
::normalizeContainerPath( $path ) !== null );
1517 * Build a Content-Disposition header value per RFC 6266.
1519 * @param string $type One of (attachment, inline)
1520 * @param string $filename Suggested file name (should not contain slashes)
1521 * @throws FileBackendError
1525 final public static function makeContentDisposition( $type, $filename = '' ) {
1528 $type = strtolower( $type );
1529 if ( !in_array( $type, [ 'inline', 'attachment' ] ) ) {
1530 throw new InvalidArgumentException( "Invalid Content-Disposition type '$type'." );
1534 if ( strlen( $filename ) ) {
1535 $parts[] = "filename*=UTF-8''" . rawurlencode( basename( $filename ) );
1538 return implode( ';', $parts );
1542 * Validate and normalize a relative storage path.
1543 * Null is returned if the path involves directory traversal.
1544 * Traversal is insecure for FS backends and broken for others.
1546 * This uses the same traversal protection as Title::secureAndSplit().
1548 * @param string $path Storage path relative to a container
1549 * @return string|null
1551 final protected static function normalizeContainerPath( $path ) {
1552 // Normalize directory separators
1553 $path = strtr( $path, '\\', '/' );
1554 // Collapse any consecutive directory separators
1555 $path = preg_replace( '![/]{2,}!', '/', $path );
1556 // Remove any leading directory separator
1557 $path = ltrim( $path, '/' );
1558 // Use the same traversal protection as Title::secureAndSplit()
1559 if ( strpos( $path, '.' ) !== false ) {
1563 strpos( $path, './' ) === 0 ||
1564 strpos( $path, '../' ) === 0 ||
1565 strpos( $path, '/./' ) !== false ||
1566 strpos( $path, '/../' ) !== false
1576 * Yields the result of the status wrapper callback on either:
1577 * - StatusValue::newGood() if this method is called without parameters
1578 * - StatusValue::newFatal() with all parameters to this method if passed in
1581 * @return StatusValue
1583 final protected function newStatus() {
1584 $args = func_get_args();
1585 if ( count( $args ) ) {
1586 $sv = call_user_func_array( [ 'StatusValue', 'newFatal' ], $args );
1588 $sv = StatusValue
::newGood();
1591 return $this->wrapStatus( $sv );
1595 * @param StatusValue $sv
1596 * @return StatusValue Modified status or StatusValue subclass
1598 final protected function wrapStatus( StatusValue
$sv ) {
1599 return $this->statusWrapper ?
call_user_func( $this->statusWrapper
, $sv ) : $sv;
1603 * @param string $section
1604 * @return ScopedCallback|null
1606 protected function scopedProfileSection( $section ) {
1607 if ( $this->profiler
) {
1608 call_user_func( [ $this->profiler
, 'profileIn' ], $section );
1609 return new ScopedCallback( [ $this->profiler
, 'profileOut' ] );