/includes/filebackend/FileBackend.php
PHP | 1173 lines | 254 code | 67 blank | 852 comment | 34 complexity | 2960c7945e519869b2cdf29bf626f3a0 MD5 | raw file
Possible License(s): GPL-2.0, Apache-2.0, LGPL-3.0
- <?php
- /**
- * @defgroup FileBackend File backend
- * @ingroup FileRepo
- *
- * File backend is used to interact with file storage systems,
- * such as the local file system, NFS, or cloud storage systems.
- */
- /**
- * Base class for all file backends.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- * http://www.gnu.org/copyleft/gpl.html
- *
- * @file
- * @ingroup FileBackend
- * @author Aaron Schulz
- */
- /**
- * @brief Base class for all file backend classes (including multi-write backends).
- *
- * This class defines the methods as abstract that subclasses must implement.
- * Outside callers can assume that all backends will have these functions.
- *
- * All "storage paths" are of the format "mwstore://<backend>/<container>/<path>".
- * The "<path>" portion is a relative path that uses UNIX file system (FS)
- * notation, though any particular backend may not actually be using a local
- * filesystem. Therefore, the relative paths are only virtual.
- *
- * Backend contents are stored under wiki-specific container names by default.
- * For legacy reasons, this has no effect for the FS backend class, and per-wiki
- * segregation must be done by setting the container paths appropriately.
- *
- * FS-based backends are somewhat more restrictive due to the existence of real
- * directory files; a regular file cannot have the same name as a directory. Other
- * backends with virtual directories may not have this limitation. Callers should
- * store files in such a way that no files and directories are under the same path.
- *
- * Methods of subclasses should avoid throwing exceptions at all costs.
- * As a corollary, external dependencies should be kept to a minimum.
- *
- * @ingroup FileBackend
- * @since 1.19
- */
- abstract class FileBackend {
- protected $name; // string; unique backend name
- protected $wikiId; // string; unique wiki name
- protected $readOnly; // string; read-only explanation message
- protected $parallelize; // string; when to do operations in parallel
- protected $concurrency; // integer; how many operations can be done in parallel
- /** @var LockManager */
- protected $lockManager;
- /** @var FileJournal */
- protected $fileJournal;
- /**
- * Create a new backend instance from configuration.
- * This should only be called from within FileBackendGroup.
- *
- * $config includes:
- * - name : The unique name of this backend.
- * This should consist of alphanumberic, '-', and '_' characters.
- * This name should not be changed after use.
- * - wikiId : Prefix to container names that is unique to this wiki.
- * It should only consist of alphanumberic, '-', and '_' characters.
- * - lockManager : Registered name of a file lock manager to use.
- * - fileJournal : File journal configuration; see FileJournal::factory().
- * Journals simply log changes to files stored in the backend.
- * - readOnly : Write operations are disallowed if this is a non-empty string.
- * It should be an explanation for the backend being read-only.
- * - parallelize : When to do file operations in parallel (when possible).
- * Allowed values are "implicit", "explicit" and "off".
- * - concurrency : How many file operations can be done in parallel.
- *
- * @param $config Array
- * @throws MWException
- */
- public function __construct( array $config ) {
- $this->name = $config['name'];
- if ( !preg_match( '!^[a-zA-Z0-9-_]{1,255}$!', $this->name ) ) {
- throw new MWException( "Backend name `{$this->name}` is invalid." );
- }
- $this->wikiId = isset( $config['wikiId'] )
- ? $config['wikiId']
- : wfWikiID(); // e.g. "my_wiki-en_"
- $this->lockManager = ( $config['lockManager'] instanceof LockManager )
- ? $config['lockManager']
- : LockManagerGroup::singleton()->get( $config['lockManager'] );
- $this->fileJournal = isset( $config['fileJournal'] )
- ? ( ( $config['fileJournal'] instanceof FileJournal )
- ? $config['fileJournal']
- : FileJournal::factory( $config['fileJournal'], $this->name ) )
- : FileJournal::factory( array( 'class' => 'NullFileJournal' ), $this->name );
- $this->readOnly = isset( $config['readOnly'] )
- ? (string)$config['readOnly']
- : '';
- $this->parallelize = isset( $config['parallelize'] )
- ? (string)$config['parallelize']
- : 'off';
- $this->concurrency = isset( $config['concurrency'] )
- ? (int)$config['concurrency']
- : 50;
- }
- /**
- * Get the unique backend name.
- * We may have multiple different backends of the same type.
- * For example, we can have two Swift backends using different proxies.
- *
- * @return string
- */
- final public function getName() {
- return $this->name;
- }
- /**
- * Get the wiki identifier used for this backend (possibly empty)
- *
- * @return string
- * @since 1.20
- */
- final public function getWikiId() {
- return $this->wikiId;
- }
- /**
- * Check if this backend is read-only
- *
- * @return bool
- */
- final public function isReadOnly() {
- return ( $this->readOnly != '' );
- }
- /**
- * Get an explanatory message if this backend is read-only
- *
- * @return string|bool Returns false if the backend is not read-only
- */
- final public function getReadOnlyReason() {
- return ( $this->readOnly != '' ) ? $this->readOnly : false;
- }
- /**
- * This is the main entry point into the backend for write operations.
- * Callers supply an ordered list of operations to perform as a transaction.
- * Files will be locked, the stat cache cleared, and then the operations attempted.
- * If any serious errors occur, all attempted operations will be rolled back.
- *
- * $ops is an array of arrays. The outer array holds a list of operations.
- * Each inner array is a set of key value pairs that specify an operation.
- *
- * Supported operations and their parameters. The supported actions are:
- * - create
- * - store
- * - copy
- * - move
- * - delete
- * - null
- *
- * a) Create a new file in storage with the contents of a string
- * @code
- * array(
- * 'op' => 'create',
- * 'dst' => <storage path>,
- * 'content' => <string of new file contents>,
- * 'overwrite' => <boolean>,
- * 'overwriteSame' => <boolean>,
- * 'disposition' => <Content-Disposition header value>
- * );
- * @endcode
- *
- * b) Copy a file system file into storage
- * @code
- * array(
- * 'op' => 'store',
- * 'src' => <file system path>,
- * 'dst' => <storage path>,
- * 'overwrite' => <boolean>,
- * 'overwriteSame' => <boolean>,
- * 'disposition' => <Content-Disposition header value>
- * )
- * @endcode
- *
- * c) Copy a file within storage
- * @code
- * array(
- * 'op' => 'copy',
- * 'src' => <storage path>,
- * 'dst' => <storage path>,
- * 'overwrite' => <boolean>,
- * 'overwriteSame' => <boolean>,
- * 'disposition' => <Content-Disposition header value>
- * )
- * @endcode
- *
- * d) Move a file within storage
- * @code
- * array(
- * 'op' => 'move',
- * 'src' => <storage path>,
- * 'dst' => <storage path>,
- * 'overwrite' => <boolean>,
- * 'overwriteSame' => <boolean>,
- * 'disposition' => <Content-Disposition header value>
- * )
- * @endcode
- *
- * e) Delete a file within storage
- * @code
- * array(
- * 'op' => 'delete',
- * 'src' => <storage path>,
- * 'ignoreMissingSource' => <boolean>
- * )
- * @endcode
- *
- * f) Do nothing (no-op)
- * @code
- * array(
- * 'op' => 'null',
- * )
- * @endcode
- *
- * Boolean flags for operations (operation-specific):
- * - ignoreMissingSource : The operation will simply succeed and do
- * nothing if the source file does not exist.
- * - overwrite : Any destination file will be overwritten.
- * - overwriteSame : An error will not be given if a file already
- * exists at the destination that has the same
- * contents as the new contents to be written there.
- * - disposition : When supplied, the backend will add a Content-Disposition
- * header when GETs/HEADs of the destination file are made.
- * Backends that don't support file metadata will ignore this.
- * See http://tools.ietf.org/html/rfc6266 (since 1.20).
- *
- * $opts is an associative of boolean flags, including:
- * - force : Operation precondition errors no longer trigger an abort.
- * Any remaining operations are still attempted. Unexpected
- * failures may still cause remaning operations to be aborted.
- * - nonLocking : No locks are acquired for the operations.
- * This can increase performance for non-critical writes.
- * This has no effect unless the 'force' flag is set.
- * - allowStale : Don't require the latest available data.
- * This can increase performance for non-critical writes.
- * This has no effect unless the 'force' flag is set.
- * - nonJournaled : Don't log this operation batch in the file journal.
- * This limits the ability of recovery scripts.
- * - parallelize : Try to do operations in parallel when possible.
- * - bypassReadOnly : Allow writes in read-only mode (since 1.20).
- * - preserveCache : Don't clear the process cache before checking files.
- * This should only be used if all entries in the process
- * cache were added after the files were already locked (since 1.20).
- *
- * @remarks Remarks on locking:
- * File system paths given to operations should refer to files that are
- * already locked or otherwise safe from modification from other processes.
- * Normally these files will be new temp files, which should be adequate.
- *
- * @par Return value:
- *
- * This returns a Status, which contains all warnings and fatals that occurred
- * during the operation. The 'failCount', 'successCount', and 'success' members
- * will reflect each operation attempted.
- *
- * The status will be "OK" unless:
- * - a) unexpected operation errors occurred (network partitions, disk full...)
- * - b) significant operation errors occurred and 'force' was not set
- *
- * @param $ops Array List of operations to execute in order
- * @param $opts Array Batch operation options
- * @return Status
- */
- final public function doOperations( array $ops, array $opts = array() ) {
- if ( empty( $opts['bypassReadOnly'] ) && $this->isReadOnly() ) {
- return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
- }
- if ( empty( $opts['force'] ) ) { // sanity
- unset( $opts['nonLocking'] );
- unset( $opts['allowStale'] );
- }
- $opts['concurrency'] = 1; // off
- if ( $this->parallelize === 'implicit' ) {
- if ( !isset( $opts['parallelize'] ) || $opts['parallelize'] ) {
- $opts['concurrency'] = $this->concurrency;
- }
- } elseif ( $this->parallelize === 'explicit' ) {
- if ( !empty( $opts['parallelize'] ) ) {
- $opts['concurrency'] = $this->concurrency;
- }
- }
- return $this->doOperationsInternal( $ops, $opts );
- }
- /**
- * @see FileBackend::doOperations()
- */
- abstract protected function doOperationsInternal( array $ops, array $opts );
- /**
- * Same as doOperations() except it takes a single operation.
- * If you are doing a batch of operations that should either
- * all succeed or all fail, then use that function instead.
- *
- * @see FileBackend::doOperations()
- *
- * @param $op Array Operation
- * @param $opts Array Operation options
- * @return Status
- */
- final public function doOperation( array $op, array $opts = array() ) {
- return $this->doOperations( array( $op ), $opts );
- }
- /**
- * Performs a single create operation.
- * This sets $params['op'] to 'create' and passes it to doOperation().
- *
- * @see FileBackend::doOperation()
- *
- * @param $params Array Operation parameters
- * @param $opts Array Operation options
- * @return Status
- */
- final public function create( array $params, array $opts = array() ) {
- return $this->doOperation( array( 'op' => 'create' ) + $params, $opts );
- }
- /**
- * Performs a single store operation.
- * This sets $params['op'] to 'store' and passes it to doOperation().
- *
- * @see FileBackend::doOperation()
- *
- * @param $params Array Operation parameters
- * @param $opts Array Operation options
- * @return Status
- */
- final public function store( array $params, array $opts = array() ) {
- return $this->doOperation( array( 'op' => 'store' ) + $params, $opts );
- }
- /**
- * Performs a single copy operation.
- * This sets $params['op'] to 'copy' and passes it to doOperation().
- *
- * @see FileBackend::doOperation()
- *
- * @param $params Array Operation parameters
- * @param $opts Array Operation options
- * @return Status
- */
- final public function copy( array $params, array $opts = array() ) {
- return $this->doOperation( array( 'op' => 'copy' ) + $params, $opts );
- }
- /**
- * Performs a single move operation.
- * This sets $params['op'] to 'move' and passes it to doOperation().
- *
- * @see FileBackend::doOperation()
- *
- * @param $params Array Operation parameters
- * @param $opts Array Operation options
- * @return Status
- */
- final public function move( array $params, array $opts = array() ) {
- return $this->doOperation( array( 'op' => 'move' ) + $params, $opts );
- }
- /**
- * Performs a single delete operation.
- * This sets $params['op'] to 'delete' and passes it to doOperation().
- *
- * @see FileBackend::doOperation()
- *
- * @param $params Array Operation parameters
- * @param $opts Array Operation options
- * @return Status
- */
- final public function delete( array $params, array $opts = array() ) {
- return $this->doOperation( array( 'op' => 'delete' ) + $params, $opts );
- }
- /**
- * Perform a set of independent file operations on some files.
- *
- * This does no locking, nor journaling, and possibly no stat calls.
- * Any destination files that already exist will be overwritten.
- * This should *only* be used on non-original files, like cache files.
- *
- * Supported operations and their parameters:
- * - create
- * - store
- * - copy
- * - move
- * - delete
- * - null
- *
- * a) Create a new file in storage with the contents of a string
- * @code
- * array(
- * 'op' => 'create',
- * 'dst' => <storage path>,
- * 'content' => <string of new file contents>,
- * 'disposition' => <Content-Disposition header value>
- * )
- * @endcode
- * b) Copy a file system file into storage
- * @code
- * array(
- * 'op' => 'store',
- * 'src' => <file system path>,
- * 'dst' => <storage path>,
- * 'disposition' => <Content-Disposition header value>
- * )
- * @endcode
- * c) Copy a file within storage
- * @code
- * array(
- * 'op' => 'copy',
- * 'src' => <storage path>,
- * 'dst' => <storage path>,
- * 'disposition' => <Content-Disposition header value>
- * )
- * @endcode
- * d) Move a file within storage
- * @code
- * array(
- * 'op' => 'move',
- * 'src' => <storage path>,
- * 'dst' => <storage path>,
- * 'disposition' => <Content-Disposition header value>
- * )
- * @endcode
- * e) Delete a file within storage
- * @code
- * array(
- * 'op' => 'delete',
- * 'src' => <storage path>,
- * 'ignoreMissingSource' => <boolean>
- * )
- * @endcode
- * f) Do nothing (no-op)
- * @code
- * array(
- * 'op' => 'null',
- * )
- * @endcode
- *
- * @par Boolean flags for operations (operation-specific):
- * - ignoreMissingSource : The operation will simply succeed and do
- * nothing if the source file does not exist.
- * - disposition : When supplied, the backend will add a Content-Disposition
- * header when GETs/HEADs of the destination file are made.
- * Backends that don't support file metadata will ignore this.
- * See http://tools.ietf.org/html/rfc6266 (since 1.20).
- *
- * $opts is an associative of boolean flags, including:
- * - bypassReadOnly : Allow writes in read-only mode (since 1.20)
- *
- * @par Return value:
- * This returns a Status, which contains all warnings and fatals that occurred
- * during the operation. The 'failCount', 'successCount', and 'success' members
- * will reflect each operation attempted for the given files. The status will be
- * considered "OK" as long as no fatal errors occurred.
- *
- * @param $ops Array Set of operations to execute
- * @param $opts Array Batch operation options
- * @return Status
- * @since 1.20
- */
- final public function doQuickOperations( array $ops, array $opts = array() ) {
- if ( empty( $opts['bypassReadOnly'] ) && $this->isReadOnly() ) {
- return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
- }
- foreach ( $ops as &$op ) {
- $op['overwrite'] = true; // avoids RTTs in key/value stores
- }
- return $this->doQuickOperationsInternal( $ops );
- }
- /**
- * @see FileBackend::doQuickOperations()
- * @since 1.20
- */
- abstract protected function doQuickOperationsInternal( array $ops );
- /**
- * Same as doQuickOperations() except it takes a single operation.
- * If you are doing a batch of operations, then use that function instead.
- *
- * @see FileBackend::doQuickOperations()
- *
- * @param $op Array Operation
- * @return Status
- * @since 1.20
- */
- final public function doQuickOperation( array $op ) {
- return $this->doQuickOperations( array( $op ) );
- }
- /**
- * Performs a single quick create operation.
- * This sets $params['op'] to 'create' and passes it to doQuickOperation().
- *
- * @see FileBackend::doQuickOperation()
- *
- * @param $params Array Operation parameters
- * @return Status
- * @since 1.20
- */
- final public function quickCreate( array $params ) {
- return $this->doQuickOperation( array( 'op' => 'create' ) + $params );
- }
- /**
- * Performs a single quick store operation.
- * This sets $params['op'] to 'store' and passes it to doQuickOperation().
- *
- * @see FileBackend::doQuickOperation()
- *
- * @param $params Array Operation parameters
- * @return Status
- * @since 1.20
- */
- final public function quickStore( array $params ) {
- return $this->doQuickOperation( array( 'op' => 'store' ) + $params );
- }
- /**
- * Performs a single quick copy operation.
- * This sets $params['op'] to 'copy' and passes it to doQuickOperation().
- *
- * @see FileBackend::doQuickOperation()
- *
- * @param $params Array Operation parameters
- * @return Status
- * @since 1.20
- */
- final public function quickCopy( array $params ) {
- return $this->doQuickOperation( array( 'op' => 'copy' ) + $params );
- }
- /**
- * Performs a single quick move operation.
- * This sets $params['op'] to 'move' and passes it to doQuickOperation().
- *
- * @see FileBackend::doQuickOperation()
- *
- * @param $params Array Operation parameters
- * @return Status
- * @since 1.20
- */
- final public function quickMove( array $params ) {
- return $this->doQuickOperation( array( 'op' => 'move' ) + $params );
- }
- /**
- * Performs a single quick delete operation.
- * This sets $params['op'] to 'delete' and passes it to doQuickOperation().
- *
- * @see FileBackend::doQuickOperation()
- *
- * @param $params Array Operation parameters
- * @return Status
- * @since 1.20
- */
- final public function quickDelete( array $params ) {
- return $this->doQuickOperation( array( 'op' => 'delete' ) + $params );
- }
- /**
- * Concatenate a list of storage files into a single file system file.
- * The target path should refer to a file that is already locked or
- * otherwise safe from modification from other processes. Normally,
- * the file will be a new temp file, which should be adequate.
- *
- * @param $params Array Operation parameters
- * $params include:
- * - srcs : ordered source storage paths (e.g. chunk1, chunk2, ...)
- * - dst : file system path to 0-byte temp file
- * @return Status
- */
- abstract public function concatenate( array $params );
- /**
- * Prepare a storage directory for usage.
- * This will create any required containers and parent directories.
- * Backends using key/value stores only need to create the container.
- *
- * The 'noAccess' and 'noListing' parameters works the same as in secure(),
- * except they are only applied *if* the directory/container had to be created.
- * These flags should always be set for directories that have private files.
- *
- * @param $params Array
- * $params include:
- * - dir : storage directory
- * - noAccess : try to deny file access (since 1.20)
- * - noListing : try to deny file listing (since 1.20)
- * - bypassReadOnly : allow writes in read-only mode (since 1.20)
- * @return Status
- */
- final public function prepare( array $params ) {
- if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
- return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
- }
- return $this->doPrepare( $params );
- }
- /**
- * @see FileBackend::prepare()
- */
- abstract protected function doPrepare( array $params );
- /**
- * Take measures to block web access to a storage directory and
- * the container it belongs to. FS backends might add .htaccess
- * files whereas key/value store backends might revoke container
- * access to the storage user representing end-users in web requests.
- * This is not guaranteed to actually do anything.
- *
- * @param $params Array
- * $params include:
- * - dir : storage directory
- * - noAccess : try to deny file access
- * - noListing : try to deny file listing
- * - bypassReadOnly : allow writes in read-only mode (since 1.20)
- * @return Status
- */
- final public function secure( array $params ) {
- if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
- return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
- }
- return $this->doSecure( $params );
- }
- /**
- * @see FileBackend::secure()
- */
- abstract protected function doSecure( array $params );
- /**
- * Remove measures to block web access to a storage directory and
- * the container it belongs to. FS backends might remove .htaccess
- * files whereas key/value store backends might grant container
- * access to the storage user representing end-users in web requests.
- * This essentially can undo the result of secure() calls.
- *
- * @param $params Array
- * $params include:
- * - dir : storage directory
- * - access : try to allow file access
- * - listing : try to allow file listing
- * - bypassReadOnly : allow writes in read-only mode (since 1.20)
- * @return Status
- * @since 1.20
- */
- final public function publish( array $params ) {
- if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
- return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
- }
- return $this->doPublish( $params );
- }
- /**
- * @see FileBackend::publish()
- */
- abstract protected function doPublish( array $params );
- /**
- * Delete a storage directory if it is empty.
- * Backends using key/value stores may do nothing unless the directory
- * is that of an empty container, in which case it will be deleted.
- *
- * @param $params Array
- * $params include:
- * - dir : storage directory
- * - recursive : recursively delete empty subdirectories first (since 1.20)
- * - bypassReadOnly : allow writes in read-only mode (since 1.20)
- * @return Status
- */
- final public function clean( array $params ) {
- if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
- return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
- }
- return $this->doClean( $params );
- }
- /**
- * @see FileBackend::clean()
- */
- abstract protected function doClean( array $params );
- /**
- * Check if a file exists at a storage path in the backend.
- * This returns false if only a directory exists at the path.
- *
- * @param $params Array
- * $params include:
- * - src : source storage path
- * - latest : use the latest available data
- * @return bool|null Returns null on failure
- */
- abstract public function fileExists( array $params );
- /**
- * Get the last-modified timestamp of the file at a storage path.
- *
- * @param $params Array
- * $params include:
- * - src : source storage path
- * - latest : use the latest available data
- * @return string|bool TS_MW timestamp or false on failure
- */
- abstract public function getFileTimestamp( array $params );
- /**
- * Get the contents of a file at a storage path in the backend.
- * This should be avoided for potentially large files.
- *
- * @param $params Array
- * $params include:
- * - src : source storage path
- * - latest : use the latest available data
- * @return string|bool Returns false on failure
- */
- abstract public function getFileContents( array $params );
- /**
- * Get the size (bytes) of a file at a storage path in the backend.
- *
- * @param $params Array
- * $params include:
- * - src : source storage path
- * - latest : use the latest available data
- * @return integer|bool Returns false on failure
- */
- abstract public function getFileSize( array $params );
- /**
- * Get quick information about a file at a storage path in the backend.
- * If the file does not exist, then this returns false.
- * Otherwise, the result is an associative array that includes:
- * - mtime : the last-modified timestamp (TS_MW)
- * - size : the file size (bytes)
- * Additional values may be included for internal use only.
- *
- * @param $params Array
- * $params include:
- * - src : source storage path
- * - latest : use the latest available data
- * @return Array|bool|null Returns null on failure
- */
- abstract public function getFileStat( array $params );
- /**
- * Get a SHA-1 hash of the file at a storage path in the backend.
- *
- * @param $params Array
- * $params include:
- * - src : source storage path
- * - latest : use the latest available data
- * @return string|bool Hash string or false on failure
- */
- abstract public function getFileSha1Base36( array $params );
- /**
- * Get the properties of the file at a storage path in the backend.
- * Returns FSFile::placeholderProps() on failure.
- *
- * @param $params Array
- * $params include:
- * - src : source storage path
- * - latest : use the latest available data
- * @return Array
- */
- abstract public function getFileProps( array $params );
- /**
- * Stream the file at a storage path in the backend.
- * If the file does not exists, an HTTP 404 error will be given.
- * Appropriate HTTP headers (Status, Content-Type, Content-Length)
- * will be sent if streaming began, while none will be sent otherwise.
- * Implementations should flush the output buffer before sending data.
- *
- * @param $params Array
- * $params include:
- * - src : source storage path
- * - headers : list of additional HTTP headers to send on success
- * - latest : use the latest available data
- * @return Status
- */
- abstract public function streamFile( array $params );
- /**
- * Returns a file system file, identical to the file at a storage path.
- * The file returned is either:
- * - a) A local copy of the file at a storage path in the backend.
- * The temporary copy will have the same extension as the source.
- * - b) An original of the file at a storage path in the backend.
- * Temporary files may be purged when the file object falls out of scope.
- *
- * Write operations should *never* be done on this file as some backends
- * may do internal tracking or may be instances of FileBackendMultiWrite.
- * In that later case, there are copies of the file that must stay in sync.
- * Additionally, further calls to this function may return the same file.
- *
- * @param $params Array
- * $params include:
- * - src : source storage path
- * - latest : use the latest available data
- * @return FSFile|null Returns null on failure
- */
- abstract public function getLocalReference( array $params );
- /**
- * Get a local copy on disk of the file at a storage path in the backend.
- * The temporary copy will have the same file extension as the source.
- * Temporary files may be purged when the file object falls out of scope.
- *
- * @param $params Array
- * $params include:
- * - src : source storage path
- * - latest : use the latest available data
- * @return TempFSFile|null Returns null on failure
- */
- abstract public function getLocalCopy( array $params );
- /**
- * Check if a directory exists at a given storage path.
- * Backends using key/value stores will check if the path is a
- * virtual directory, meaning there are files under the given directory.
- *
- * Storage backends with eventual consistency might return stale data.
- *
- * @param $params array
- * $params include:
- * - dir : storage directory
- * @return bool|null Returns null on failure
- * @since 1.20
- */
- abstract public function directoryExists( array $params );
- /**
- * Get an iterator to list *all* directories under a storage directory.
- * If the directory is of the form "mwstore://backend/container",
- * then all directories in the container will be listed.
- * If the directory is of form "mwstore://backend/container/dir",
- * then all directories directly under that directory will be listed.
- * Results will be storage directories relative to the given directory.
- *
- * Storage backends with eventual consistency might return stale data.
- *
- * @param $params array
- * $params include:
- * - dir : storage directory
- * - topOnly : only return direct child dirs of the directory
- * @return Traversable|Array|null Returns null on failure
- * @since 1.20
- */
- abstract public function getDirectoryList( array $params );
- /**
- * Same as FileBackend::getDirectoryList() except only lists
- * directories that are immediately under the given directory.
- *
- * Storage backends with eventual consistency might return stale data.
- *
- * @param $params array
- * $params include:
- * - dir : storage directory
- * @return Traversable|Array|null Returns null on failure
- * @since 1.20
- */
- final public function getTopDirectoryList( array $params ) {
- return $this->getDirectoryList( array( 'topOnly' => true ) + $params );
- }
- /**
- * Get an iterator to list *all* stored files under a storage directory.
- * If the directory is of the form "mwstore://backend/container",
- * then all files in the container will be listed.
- * If the directory is of form "mwstore://backend/container/dir",
- * then all files under that directory will be listed.
- * Results will be storage paths relative to the given directory.
- *
- * Storage backends with eventual consistency might return stale data.
- *
- * @param $params array
- * $params include:
- * - dir : storage directory
- * - topOnly : only return direct child files of the directory (since 1.20)
- * @return Traversable|Array|null Returns null on failure
- */
- abstract public function getFileList( array $params );
- /**
- * Same as FileBackend::getFileList() except only lists
- * files that are immediately under the given directory.
- *
- * Storage backends with eventual consistency might return stale data.
- *
- * @param $params array
- * $params include:
- * - dir : storage directory
- * @return Traversable|Array|null Returns null on failure
- * @since 1.20
- */
- final public function getTopFileList( array $params ) {
- return $this->getFileList( array( 'topOnly' => true ) + $params );
- }
- /**
- * Preload persistent file stat and property cache into in-process cache.
- * This should be used when stat calls will be made on a known list of a many files.
- *
- * @param $paths Array Storage paths
- * @return void
- */
- public function preloadCache( array $paths ) {}
- /**
- * Invalidate any in-process file stat and property cache.
- * If $paths is given, then only the cache for those files will be cleared.
- *
- * @param $paths Array Storage paths (optional)
- * @return void
- */
- public function clearCache( array $paths = null ) {}
- /**
- * Lock the files at the given storage paths in the backend.
- * This will either lock all the files or none (on failure).
- *
- * Callers should consider using getScopedFileLocks() instead.
- *
- * @param $paths Array Storage paths
- * @param $type integer LockManager::LOCK_* constant
- * @return Status
- */
- final public function lockFiles( array $paths, $type ) {
- return $this->lockManager->lock( $paths, $type );
- }
- /**
- * Unlock the files at the given storage paths in the backend.
- *
- * @param $paths Array Storage paths
- * @param $type integer LockManager::LOCK_* constant
- * @return Status
- */
- final public function unlockFiles( array $paths, $type ) {
- return $this->lockManager->unlock( $paths, $type );
- }
- /**
- * Lock the files at the given storage paths in the backend.
- * This will either lock all the files or none (on failure).
- * On failure, the status object will be updated with errors.
- *
- * Once the return value goes out scope, the locks will be released and
- * the status updated. Unlock fatals will not change the status "OK" value.
- *
- * @param $paths Array Storage paths
- * @param $type integer LockManager::LOCK_* constant
- * @param $status Status Status to update on lock/unlock
- * @return ScopedLock|null Returns null on failure
- */
- final public function getScopedFileLocks( array $paths, $type, Status $status ) {
- return ScopedLock::factory( $this->lockManager, $paths, $type, $status );
- }
- /**
- * Get an array of scoped locks needed for a batch of file operations.
- *
- * Normally, FileBackend::doOperations() handles locking, unless
- * the 'nonLocking' param is passed in. This function is useful if you
- * want the files to be locked for a broader scope than just when the
- * files are changing. For example, if you need to update DB metadata,
- * you may want to keep the files locked until finished.
- *
- * @see FileBackend::doOperations()
- *
- * @param $ops Array List of file operations to FileBackend::doOperations()
- * @param $status Status Status to update on lock/unlock
- * @return Array List of ScopedFileLocks or null values
- * @since 1.20
- */
- abstract public function getScopedLocksForOps( array $ops, Status $status );
- /**
- * Get the root storage path of this backend.
- * All container paths are "subdirectories" of this path.
- *
- * @return string Storage path
- * @since 1.20
- */
- final public function getRootStoragePath() {
- return "mwstore://{$this->name}";
- }
- /**
- * Get the file journal object for this backend
- *
- * @return FileJournal
- */
- final public function getJournal() {
- return $this->fileJournal;
- }
- /**
- * Check if a given path is a "mwstore://" path.
- * This does not do any further validation or any existence checks.
- *
- * @param $path string
- * @return bool
- */
- final public static function isStoragePath( $path ) {
- return ( strpos( $path, 'mwstore://' ) === 0 );
- }
- /**
- * Split a storage path into a backend name, a container name,
- * and a relative file path. The relative path may be the empty string.
- * This does not do any path normalization or traversal checks.
- *
- * @param $storagePath string
- * @return Array (backend, container, rel object) or (null, null, null)
- */
- final public static function splitStoragePath( $storagePath ) {
- if ( self::isStoragePath( $storagePath ) ) {
- // Remove the "mwstore://" prefix and split the path
- $parts = explode( '/', substr( $storagePath, 10 ), 3 );
- if ( count( $parts ) >= 2 && $parts[0] != '' && $parts[1] != '' ) {
- if ( count( $parts ) == 3 ) {
- return $parts; // e.g. "backend/container/path"
- } else {
- return array( $parts[0], $parts[1], '' ); // e.g. "backend/container"
- }
- }
- }
- return array( null, null, null );
- }
- /**
- * Normalize a storage path by cleaning up directory separators.
- * Returns null if the path is not of the format of a valid storage path.
- *
- * @param $storagePath string
- * @return string|null
- */
- final public static function normalizeStoragePath( $storagePath ) {
- list( $backend, $container, $relPath ) = self::splitStoragePath( $storagePath );
- if ( $relPath !== null ) { // must be for this backend
- $relPath = self::normalizeContainerPath( $relPath );
- if ( $relPath !== null ) {
- return ( $relPath != '' )
- ? "mwstore://{$backend}/{$container}/{$relPath}"
- : "mwstore://{$backend}/{$container}";
- }
- }
- return null;
- }
- /**
- * Get the parent storage directory of a storage path.
- * This returns a path like "mwstore://backend/container",
- * "mwstore://backend/container/...", or null if there is no parent.
- *
- * @param $storagePath string
- * @return string|null
- */
- final public static function parentStoragePath( $storagePath ) {
- $storagePath = dirname( $storagePath );
- list( $b, $cont, $rel ) = self::splitStoragePath( $storagePath );
- return ( $rel === null ) ? null : $storagePath;
- }
- /**
- * Get the final extension from a storage or FS path
- *
- * @param $path string
- * @return string
- */
- final public static function extensionFromPath( $path ) {
- $i = strrpos( $path, '.' );
- return strtolower( $i ? substr( $path, $i + 1 ) : '' );
- }
- /**
- * Check if a relative path has no directory traversals
- *
- * @param $path string
- * @return bool
- * @since 1.20
- */
- final public static function isPathTraversalFree( $path ) {
- return ( self::normalizeContainerPath( $path ) !== null );
- }
- /**
- * Build a Content-Disposition header value per RFC 6266.
- *
- * @param $type string One of (attachment, inline)
- * @param $filename string Suggested file name (should not contain slashes)
- * @return string
- * @since 1.20
- */
- final public static function makeContentDisposition( $type, $filename = '' ) {
- $parts = array();
- $type = strtolower( $type );
- if ( !in_array( $type, array( 'inline', 'attachment' ) ) ) {
- throw new MWException( "Invalid Content-Disposition type '$type'." );
- }
- $parts[] = $type;
- if ( strlen( $filename ) ) {
- $parts[] = "filename*=UTF-8''" . rawurlencode( basename( $filename ) );
- }
- return implode( ';', $parts );
- }
- /**
- * Validate and normalize a relative storage path.
- * Null is returned if the path involves directory traversal.
- * Traversal is insecure for FS backends and broken for others.
- *
- * This uses the same traversal protection as Title::secureAndSplit().
- *
- * @param $path string Storage path relative to a container
- * @return string|null
- */
- final protected static function normalizeContainerPath( $path ) {
- // Normalize directory separators
- $path = strtr( $path, '\\', '/' );
- // Collapse any consecutive directory separators
- $path = preg_replace( '![/]{2,}!', '/', $path );
- // Remove any leading directory separator
- $path = ltrim( $path, '/' );
- // Use the same traversal protection as Title::secureAndSplit()
- if ( strpos( $path, '.' ) !== false ) {
- if (
- $path === '.' ||
- $path === '..' ||
- strpos( $path, './' ) === 0 ||
- strpos( $path, '../' ) === 0 ||
- strpos( $path, '/./' ) !== false ||
- strpos( $path, '/../' ) !== false
- ) {
- return null;
- }
- }
- return $path;
- }
- }