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<?php
/**
* @defgroup FileBackend File backend
* @ingroup FileRepo
*
* This module regroup classes meant for MediaWiki to interacts with
*/
/**
* @file
* @ingroup FileBackend
* @author Aaron Schulz
*/
/**
* 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 paths use UNIX file system (FS) notation, though any particular backend may
* not actually be using a local filesystem. Therefore, the 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 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
/** @var LockManager */
protected $lockManager;
/**
* 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.
* This should consist of alphanumberic, '-', and '_' characters.
* 'lockManager' : Registered name of a file lock manager to use.
* 'readOnly' : Write operations are disallowed if this is a non-empty string.
* It should be an explanation for the backend being read-only.
*
* @param $config Array
*/
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->readOnly = isset( $config['readOnly'] )
? (string)$config['readOnly']
: '';
}
/**
* 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;
}
/**
* 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|false Returns falls 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:
* a) Create a new file in storage with the contents of a string
* array(
* 'op' => 'create',
* 'dst' => <storage path>,
* 'content' => <string of new file contents>,
* 'overwrite' => <boolean>,
* 'overwriteSame' => <boolean>
* )
* b) Copy a file system file into storage
* array(
* 'op' => 'store',
* 'src' => <file system path>,
* 'dst' => <storage path>,
* 'overwrite' => <boolean>,
* 'overwriteSame' => <boolean>
* )
* c) Copy a file within storage
* array(
* 'op' => 'copy',
* 'src' => <storage path>,
* 'dst' => <storage path>,
* 'overwrite' => <boolean>,
* 'overwriteSame' => <boolean>
* )
* d) Move a file within storage
* array(
* 'op' => 'move',
* 'src' => <storage path>,
* 'dst' => <storage path>,
* 'overwrite' => <boolean>,
* 'overwriteSame' => <boolean>
* )
* e) Delete a file within storage
* array(
* 'op' => 'delete',
* 'src' => <storage path>,
* 'ignoreMissingSource' => <boolean>
* )
* f) Do nothing (no-op)
* array(
* 'op' => 'null',
* )
*
* 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.
*
* $opts is an associative of boolean flags, including:
* 'force' : Errors that would normally cause a rollback do not.
* The remaining operations are still attempted if any fail.
* '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.
*
* 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.
*
* Return value:
* This returns a Status, which contains all warnings and fatals that occured
* 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 occured 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 ( $this->isReadOnly() ) {
return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
}
if ( empty( $opts['force'] ) ) { // sanity
unset( $opts['nonLocking'] );
unset( $opts['allowStale'] );
}
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() ) {
$params['op'] = 'create';
return $this->doOperation( $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() ) {
$params['op'] = 'store';
return $this->doOperation( $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() ) {
$params['op'] = 'copy';
return $this->doOperation( $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() ) {
$params['op'] = 'move';
return $this->doOperation( $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() ) {
$params['op'] = 'delete';
return $this->doOperation( $params, $opts );
}
/**
* 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.
* $params include:
* srcs : ordered source storage paths (e.g. chunk1, chunk2, ...)
* dst : file system path to 0-byte temp file
*
* @param $params Array Operation parameters
* @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.
*
* $params include:
* dir : storage directory
*
* @param $params Array
* @return Status
*/
final public function prepare( array $params ) {
if ( $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 restrict container
* access to the auth user that represents end-users in web request.
* This is not guaranteed to actually do anything.
*
* $params include:
* dir : storage directory
* noAccess : try to deny file access
* noListing : try to deny file listing
*
* @param $params Array
* @return Status
*/
final public function secure( array $params ) {
if ( $this->isReadOnly() ) {
return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
}
$status = $this->doPrepare( $params ); // dir must exist to restrict it
if ( $status->isOK() ) {
$status->merge( $this->doSecure( $params ) );
}
return $status;
}
/**
* @see FileBackend::secure()
*/
abstract protected function doSecure( 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 should be deleted.
*
* $params include:
* dir : storage directory
*
* @param $params Array
* @return Status
*/
final public function clean( array $params ) {
if ( $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.
*
* $params include:
* src : source storage path
* latest : use the latest available data
*
* @param $params Array
* @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.
*
* $params include:
* src : source storage path
* latest : use the latest available data
*
* @param $params Array
* @return string|false 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.
*
* $params include:
* src : source storage path
* latest : use the latest available data
*
* @param $params Array
* @return string|false Returns false on failure
*/
abstract public function getFileContents( array $params );
/**
* Get the size (bytes) of a file at a storage path in the backend.
*
* $params include:
* src : source storage path
* latest : use the latest available data
*
* @param $params Array
* @return integer|false 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.
*
* $params include:
* src : source storage path
* latest : use the latest available data
*
* @param $params Array
* @return Array|false|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.
*
* $params include:
* src : source storage path
* latest : use the latest available data
*
* @param $params Array
* @return string|false 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.
*
* $params include:
* src : source storage path
* latest : use the latest available data
*
* @param $params Array
* @return Array
*/
abstract public function getFileProps( array $params );
/**
* Stream the file at a storage path in the backend.
* If the file does not exists, a 404 error will be given.
* Appropriate HTTP headers (Status, Content-Type, Content-Length)
* must be sent if streaming began, while none should be sent otherwise.
* Implementations should flush the output buffer before sending data.
*
* $params include:
* src : source storage path
* headers : additional HTTP headers to send on success
* latest : use the latest available data
*
* @param $params Array
* @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.
*
* $params include:
* src : source storage path
* latest : use the latest available data
*
* @param $params Array
* @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.
*
* $params include:
* src : source storage path
* latest : use the latest available data
*
* @param $params Array
* @return TempFSFile|null Returns null on failure
*/
abstract public function getLocalCopy( array $params );
/**
* Get an iterator to list out all stored files under a storage directory.
* If the directory is of the form "mwstore://backend/container",
* then all files in the container should be listed.
* If the directory is of form "mwstore://backend/container/dir",
* then all files under that container directory should be listed.
* Results should be storage paths relative to the given directory.
*
* Storage backends with eventual consistency might return stale data.
*
* $params include:
* dir : storage path directory
*
* @return Traversable|Array|null Returns null on failure
*/
abstract public function getFileList( array $params );
/**
* Invalidate any in-process file existence 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 );
}
/**
* 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;
}
/**
* 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.
*
* @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;
}
/**
* 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 ) : '' );
}
}
/**
* @brief Base class for all backends associated with a particular storage medium.
*
* This class defines the methods as abstract that subclasses must implement.
* Outside callers should *not* use functions with "Internal" in the name.
*
* The FileBackend operations are implemented using basic functions
* such as storeInternal(), copyInternal(), deleteInternal() and the like.
* This class is also responsible for path resolution and sanitization.
*
* @ingroup FileBackend
* @since 1.19
*/
abstract class FileBackendStore extends FileBackend {
/** @var Array Map of paths to small (RAM/disk) cache items */
protected $cache = array(); // (storage path => key => value)
protected $maxCacheSize = 100; // integer; max paths with entries
/** @var Array Map of paths to large (RAM/disk) cache items */
protected $expensiveCache = array(); // (storage path => key => value)
protected $maxExpensiveCacheSize = 10; // integer; max paths with entries
/** @var Array Map of container names to sharding settings */
protected $shardViaHashLevels = array(); // (container name => config array)
protected $maxFileSize = 1000000000; // integer bytes (1GB)
/**
* Get the maximum allowable file size given backend
* medium restrictions and basic performance constraints.
* Do not call this function from places outside FileBackend and FileOp.
*
* @return integer Bytes
*/
final public function maxFileSizeInternal() {
return $this->maxFileSize;
}
/**
* Check if a file can be created at a given storage path.
* FS backends should check if the parent directory exists and the file is writable.
* Backends using key/value stores should check if the container exists.
*
* @param $storagePath string
* @return bool
*/
abstract public function isPathUsableInternal( $storagePath );
/**
* Create a file in the backend with the given contents.
* Do not call this function from places outside FileBackend and FileOp.
*
* $params include:
* content : the raw file contents
* dst : destination storage path
* overwrite : overwrite any file that exists at the destination
*
* @param $params Array
* @return Status
*/
final public function createInternal( array $params ) {
wfProfileIn( __METHOD__ );
if ( strlen( $params['content'] ) > $this->maxFileSizeInternal() ) {
$status = Status::newFatal( 'backend-fail-create', $params['dst'] );
} else {
$status = $this->doCreateInternal( $params );
$this->clearCache( array( $params['dst'] ) );
}
wfProfileOut( __METHOD__ );
return $status;
}
/**
* @see FileBackendStore::createInternal()
*/
abstract protected function doCreateInternal( array $params );
/**
* Store a file into the backend from a file on disk.
* Do not call this function from places outside FileBackend and FileOp.
*
* $params include:
* src : source path on disk
* dst : destination storage path
* overwrite : overwrite any file that exists at the destination
*
* @param $params Array
* @return Status
*/
final public function storeInternal( array $params ) {
wfProfileIn( __METHOD__ );
if ( filesize( $params['src'] ) > $this->maxFileSizeInternal() ) {
$status = Status::newFatal( 'backend-fail-store', $params['dst'] );
} else {
$status = $this->doStoreInternal( $params );
$this->clearCache( array( $params['dst'] ) );
}
wfProfileOut( __METHOD__ );
return $status;
}
/**
* @see FileBackendStore::storeInternal()
*/
abstract protected function doStoreInternal( array $params );
/**
* Copy a file from one storage path to another in the backend.
* Do not call this function from places outside FileBackend and FileOp.
*
* $params include:
* src : source storage path
* dst : destination storage path
* overwrite : overwrite any file that exists at the destination
*
* @param $params Array
* @return Status
*/
final public function copyInternal( array $params ) {
wfProfileIn( __METHOD__ );
$status = $this->doCopyInternal( $params );
$this->clearCache( array( $params['dst'] ) );
wfProfileOut( __METHOD__ );
return $status;
}
/**
* @see FileBackendStore::copyInternal()
*/
abstract protected function doCopyInternal( array $params );
/**
* Delete a file at the storage path.
* Do not call this function from places outside FileBackend and FileOp.
*
* $params include:
* src : source storage path
* ignoreMissingSource : do nothing if the source file does not exist
*
* @param $params Array
* @return Status
*/
final public function deleteInternal( array $params ) {
wfProfileIn( __METHOD__ );
$status = $this->doDeleteInternal( $params );
$this->clearCache( array( $params['src'] ) );
wfProfileOut( __METHOD__ );
return $status;
}
/**
* @see FileBackendStore::deleteInternal()
*/
abstract protected function doDeleteInternal( array $params );
/**
* Move a file from one storage path to another in the backend.
* Do not call this function from places outside FileBackend and FileOp.
*
* $params include:
* src : source storage path
* dst : destination storage path
* overwrite : overwrite any file that exists at the destination
*
* @param $params Array
* @return Status
*/
final public function moveInternal( array $params ) {
wfProfileIn( __METHOD__ );
$status = $this->doMoveInternal( $params );
$this->clearCache( array( $params['src'], $params['dst'] ) );
wfProfileOut( __METHOD__ );
return $status;
}
/**
* @see FileBackendStore::moveInternal()
*/
protected function doMoveInternal( array $params ) {
// Copy source to dest
$status = $this->copyInternal( $params );
if ( $status->isOK() ) {
// Delete source (only fails due to races or medium going down)
$status->merge( $this->deleteInternal( array( 'src' => $params['src'] ) ) );
$status->setResult( true, $status->value ); // ignore delete() errors
}
return $status;
}
/**
* @see FileBackend::concatenate()
*/
final public function concatenate( array $params ) {
wfProfileIn( __METHOD__ );
$status = Status::newGood();
// Try to lock the source files for the scope of this function
$scopeLockS = $this->getScopedFileLocks( $params['srcs'], LockManager::LOCK_UW, $status );
if ( $status->isOK() ) {
// Actually do the concatenation
$status->merge( $this->doConcatenate( $params ) );
}
wfProfileOut( __METHOD__ );
return $status;
}
/**
* @see FileBackendStore::concatenate()
*/
protected function doConcatenate( array $params ) {
$status = Status::newGood();
$tmpPath = $params['dst']; // convenience
// Check that the specified temp file is valid...
wfSuppressWarnings();
$ok = ( is_file( $tmpPath ) && !filesize( $tmpPath ) );
wfRestoreWarnings();
if ( !$ok ) { // not present or not empty
$status->fatal( 'backend-fail-opentemp', $tmpPath );
return $status;
}
// Build up the temp file using the source chunks (in order)...
$tmpHandle = fopen( $tmpPath, 'ab' );
if ( $tmpHandle === false ) {
$status->fatal( 'backend-fail-opentemp', $tmpPath );
return $status;
}
foreach ( $params['srcs'] as $virtualSource ) {
// Get a local FS version of the chunk
$tmpFile = $this->getLocalReference( array( 'src' => $virtualSource ) );
if ( !$tmpFile ) {
$status->fatal( 'backend-fail-read', $virtualSource );
return $status;
}
// Get a handle to the local FS version
$sourceHandle = fopen( $tmpFile->getPath(), 'r' );
if ( $sourceHandle === false ) {
fclose( $tmpHandle );
$status->fatal( 'backend-fail-read', $virtualSource );
return $status;
}
// Append chunk to file (pass chunk size to avoid magic quotes)
if ( !stream_copy_to_stream( $sourceHandle, $tmpHandle ) ) {
fclose( $sourceHandle );
fclose( $tmpHandle );
$status->fatal( 'backend-fail-writetemp', $tmpPath );
return $status;
}
fclose( $sourceHandle );
}
if ( !fclose( $tmpHandle ) ) {
$status->fatal( 'backend-fail-closetemp', $tmpPath );
return $status;
}
clearstatcache(); // temp file changed
return $status;
}
/**
* @see FileBackend::doPrepare()
*/
final protected function doPrepare( array $params ) {
wfProfileIn( __METHOD__ );
$status = Status::newGood();
list( $fullCont, $dir, $shard ) = $this->resolveStoragePath( $params['dir'] );
if ( $dir === null ) {
$status->fatal( 'backend-fail-invalidpath', $params['dir'] );
wfProfileOut( __METHOD__ );
return $status; // invalid storage path
}
if ( $shard !== null ) { // confined to a single container/shard
$status->merge( $this->doPrepareInternal( $fullCont, $dir, $params ) );
} else { // directory is on several shards
wfDebug( __METHOD__ . ": iterating over all container shards.\n" );
list( $b, $shortCont, $r ) = self::splitStoragePath( $params['dir'] );
foreach ( $this->getContainerSuffixes( $shortCont ) as $suffix ) {
$status->merge( $this->doPrepareInternal( "{$fullCont}{$suffix}", $dir, $params ) );
}
}
wfProfileOut( __METHOD__ );
return $status;
}
/**
* @see FileBackendStore::doPrepare()
*/
protected function doPrepareInternal( $container, $dir, array $params ) {
return Status::newGood();
}
/**
* @see FileBackend::doSecure()
*/
final protected function doSecure( array $params ) {
wfProfileIn( __METHOD__ );
$status = Status::newGood();
list( $fullCont, $dir, $shard ) = $this->resolveStoragePath( $params['dir'] );
if ( $dir === null ) {
$status->fatal( 'backend-fail-invalidpath', $params['dir'] );
wfProfileOut( __METHOD__ );
return $status; // invalid storage path
}
if ( $shard !== null ) { // confined to a single container/shard
$status->merge( $this->doSecureInternal( $fullCont, $dir, $params ) );
} else { // directory is on several shards
wfDebug( __METHOD__ . ": iterating over all container shards.\n" );
list( $b, $shortCont, $r ) = self::splitStoragePath( $params['dir'] );
foreach ( $this->getContainerSuffixes( $shortCont ) as $suffix ) {
$status->merge( $this->doSecureInternal( "{$fullCont}{$suffix}", $dir, $params ) );
}
}
wfProfileOut( __METHOD__ );
return $status;
}
/**
* @see FileBackendStore::doSecure()
*/
protected function doSecureInternal( $container, $dir, array $params ) {
return Status::newGood();
}
/**
* @see FileBackend::doClean()
*/
final protected function doClean( array $params ) {
wfProfileIn( __METHOD__ );
$status = Status::newGood();
list( $fullCont, $dir, $shard ) = $this->resolveStoragePath( $params['dir'] );
if ( $dir === null ) {
$status->fatal( 'backend-fail-invalidpath', $params['dir'] );
wfProfileOut( __METHOD__ );
return $status; // invalid storage path
}
// Attempt to lock this directory...
$filesLockEx = array( $params['dir'] );
$scopedLockE = $this->getScopedFileLocks( $filesLockEx, LockManager::LOCK_EX, $status );
if ( !$status->isOK() ) {
wfProfileOut( __METHOD__ );
return $status; // abort
}
if ( $shard !== null ) { // confined to a single container/shard
$status->merge( $this->doCleanInternal( $fullCont, $dir, $params ) );
} else { // directory is on several shards
wfDebug( __METHOD__ . ": iterating over all container shards.\n" );
list( $b, $shortCont, $r ) = self::splitStoragePath( $params['dir'] );
foreach ( $this->getContainerSuffixes( $shortCont ) as $suffix ) {
$status->merge( $this->doCleanInternal( "{$fullCont}{$suffix}", $dir, $params ) );
}
}
wfProfileOut( __METHOD__ );
return $status;
}
/**
* @see FileBackendStore::doClean()
*/
protected function doCleanInternal( $container, $dir, array $params ) {
return Status::newGood();
}
/**
* @see FileBackend::fileExists()
*/
final public function fileExists( array $params ) {
wfProfileIn( __METHOD__ );
$stat = $this->getFileStat( $params );
wfProfileOut( __METHOD__ );
return ( $stat === null ) ? null : (bool)$stat; // null => failure
}
/**
* @see FileBackend::getFileTimestamp()
*/
final public function getFileTimestamp( array $params ) {
wfProfileIn( __METHOD__ );
$stat = $this->getFileStat( $params );
wfProfileOut( __METHOD__ );
return $stat ? $stat['mtime'] : false;
}
/**
* @see FileBackend::getFileSize()
*/
final public function getFileSize( array $params ) {
wfProfileIn( __METHOD__ );
$stat = $this->getFileStat( $params );
wfProfileOut( __METHOD__ );
return $stat ? $stat['size'] : false;
}
/**
* @see FileBackend::getFileStat()
*/
final public function getFileStat( array $params ) {
wfProfileIn( __METHOD__ );
$path = self::normalizeStoragePath( $params['src'] );
if ( $path === null ) {
return false; // invalid storage path
}
$latest = !empty( $params['latest'] );
if ( isset( $this->cache[$path]['stat'] ) ) {
// If we want the latest data, check that this cached
// value was in fact fetched with the latest available data.
if ( !$latest || $this->cache[$path]['stat']['latest'] ) {
wfProfileOut( __METHOD__ );
return $this->cache[$path]['stat'];
}
}
$stat = $this->doGetFileStat( $params );
if ( is_array( $stat ) ) { // don't cache negatives
$this->trimCache(); // limit memory
$this->cache[$path]['stat'] = $stat;
$this->cache[$path]['stat']['latest'] = $latest;
}
wfProfileOut( __METHOD__ );
return $stat;
}
/**
* @see FileBackendStore::getFileStat()
*/
abstract protected function doGetFileStat( array $params );
/**
* @see FileBackend::getFileContents()
*/
public function getFileContents( array $params ) {
wfProfileIn( __METHOD__ );
$tmpFile = $this->getLocalReference( $params );
if ( !$tmpFile ) {
wfProfileOut( __METHOD__ );
return false;
}
wfSuppressWarnings();
$data = file_get_contents( $tmpFile->getPath() );
wfRestoreWarnings();
wfProfileOut( __METHOD__ );
return $data;
}
/**
* @see FileBackend::getFileSha1Base36()
*/
final public function getFileSha1Base36( array $params ) {
wfProfileIn( __METHOD__ );
$path = $params['src'];
if ( isset( $this->cache[$path]['sha1'] ) ) {
wfProfileOut( __METHOD__ );
return $this->cache[$path]['sha1'];
}
$hash = $this->doGetFileSha1Base36( $params );
if ( $hash ) { // don't cache negatives
$this->trimCache(); // limit memory
$this->cache[$path]['sha1'] = $hash;
}
wfProfileOut( __METHOD__ );
return $hash;
}
/**
* @see FileBackendStore::getFileSha1Base36()
*/
protected function doGetFileSha1Base36( array $params ) {
$fsFile = $this->getLocalReference( $params );
if ( !$fsFile ) {
return false;
} else {
return $fsFile->getSha1Base36();
}
}
/**
* @see FileBackend::getFileProps()
*/
final public function getFileProps( array $params ) {
wfProfileIn( __METHOD__ );
$fsFile = $this->getLocalReference( $params );
$props = $fsFile ? $fsFile->getProps() : FSFile::placeholderProps();
wfProfileOut( __METHOD__ );
return $props;
}
/**
* @see FileBackend::getLocalReference()
*/
public function getLocalReference( array $params ) {
wfProfileIn( __METHOD__ );
$path = $params['src'];
if ( isset( $this->expensiveCache[$path]['localRef'] ) ) {
wfProfileOut( __METHOD__ );
return $this->expensiveCache[$path]['localRef'];
}
$tmpFile = $this->getLocalCopy( $params );
if ( $tmpFile ) { // don't cache negatives
$this->trimExpensiveCache(); // limit memory
$this->expensiveCache[$path]['localRef'] = $tmpFile;
}
wfProfileOut( __METHOD__ );
return $tmpFile;
}
/**
* @see FileBackend::streamFile()
*/
final public function streamFile( array $params ) {
wfProfileIn( __METHOD__ );
$status = Status::newGood();
$info = $this->getFileStat( $params );
if ( !$info ) { // let StreamFile handle the 404
$status->fatal( 'backend-fail-notexists', $params['src'] );
}
// Set output buffer and HTTP headers for stream
$extraHeaders = isset( $params['headers'] ) ? $params['headers'] : array();
$res = StreamFile::prepareForStream( $params['src'], $info, $extraHeaders );
if ( $res == StreamFile::NOT_MODIFIED ) {
// do nothing; client cache is up to date
} elseif ( $res == StreamFile::READY_STREAM ) {
$status = $this->doStreamFile( $params );
} else {
$status->fatal( 'backend-fail-stream', $params['src'] );
}
wfProfileOut( __METHOD__ );
return $status;
}
/**
* @see FileBackendStore::streamFile()
*/
protected function doStreamFile( array $params ) {
$status = Status::newGood();
$fsFile = $this->getLocalReference( $params );
if ( !$fsFile ) {
$status->fatal( 'backend-fail-stream', $params['src'] );
} elseif ( !readfile( $fsFile->getPath() ) ) {
$status->fatal( 'backend-fail-stream', $params['src'] );
}
return $status;
}
/**
* @copydoc FileBackend::getFileList()
*/
final public function getFileList( array $params ) {
list( $fullCont, $dir, $shard ) = $this->resolveStoragePath( $params['dir'] );
if ( $dir === null ) { // invalid storage path
return null;
}
if ( $shard !== null ) {
// File listing is confined to a single container/shard
return $this->getFileListInternal( $fullCont, $dir, $params );
} else {
wfDebug( __METHOD__ . ": iterating over all container shards.\n" );
// File listing spans multiple containers/shards
list( $b, $shortCont, $r ) = self::splitStoragePath( $params['dir'] );
return new FileBackendStoreShardListIterator( $this,
$fullCont, $dir, $this->getContainerSuffixes( $shortCont ), $params );
}
}
/**
* Do not call this function from places outside FileBackend
*
* @see FileBackendStore::getFileList()
*
* @param $container string Resolved container name
* @param $dir string Resolved path relative to container
* @param $params Array
* @return Traversable|Array|null
*/
abstract public function getFileListInternal( $container, $dir, array $params );
/**
* Get the list of supported operations and their corresponding FileOp classes.
*
* @return Array
*/
protected function supportedOperations() {
return array(
'store' => 'StoreFileOp',
'copy' => 'CopyFileOp',
'move' => 'MoveFileOp',
'delete' => 'DeleteFileOp',
'create' => 'CreateFileOp',
'null' => 'NullFileOp'
);
}
/**
* Return a list of FileOp objects from a list of operations.
* Do not call this function from places outside FileBackend.
*
* The result must have the same number of items as the input.
* An exception is thrown if an unsupported operation is requested.
*
* @param $ops Array Same format as doOperations()
* @return Array List of FileOp objects
* @throws MWException
*/
final public function getOperations( array $ops ) {
$supportedOps = $this->supportedOperations();
$performOps = array(); // array of FileOp objects
// Build up ordered array of FileOps...
foreach ( $ops as $operation ) {
$opName = $operation['op'];
if ( isset( $supportedOps[$opName] ) ) {
$class = $supportedOps[$opName];
// Get params for this operation
$params = $operation;
// Append the FileOp class
$performOps[] = new $class( $this, $params );
} else {
throw new MWException( "Operation `$opName` is not supported." );
}
}
return $performOps;
}
/**
* @see FileBackend::doOperationsInternal()
*/
protected function doOperationsInternal( array $ops, array $opts ) {
wfProfileIn( __METHOD__ );
$status = Status::newGood();
// Build up a list of FileOps...
$performOps = $this->getOperations( $ops );
// Acquire any locks as needed...
if ( empty( $opts['nonLocking'] ) ) {
// Build up a list of files to lock...
$filesLockEx = $filesLockSh = array();
foreach ( $performOps as $fileOp ) {
$filesLockSh = array_merge( $filesLockSh, $fileOp->storagePathsRead() );
$filesLockEx = array_merge( $filesLockEx, $fileOp->storagePathsChanged() );
}
// Optimization: if doing an EX lock anyway, don't also set an SH one
$filesLockSh = array_diff( $filesLockSh, $filesLockEx );
// Get a shared lock on the parent directory of each path changed
$filesLockSh = array_merge( $filesLockSh, array_map( 'dirname', $filesLockEx ) );
// Try to lock those files for the scope of this function...
$scopeLockS = $this->getScopedFileLocks( $filesLockSh, LockManager::LOCK_UW, $status );
$scopeLockE = $this->getScopedFileLocks( $filesLockEx, LockManager::LOCK_EX, $status );
if ( !$status->isOK() ) {
wfProfileOut( __METHOD__ );
return $status; // abort
}
}
// Clear any cache entries (after locks acquired)
$this->clearCache();
// Actually attempt the operation batch...
$subStatus = FileOp::attemptBatch( $performOps, $opts );
// Merge errors into status fields
$status->merge( $subStatus );
$status->success = $subStatus->success; // not done in merge()
wfProfileOut( __METHOD__ );
return $status;
}
/**
* @see FileBackend::clearCache()
*/
final public function clearCache( array $paths = null ) {
if ( is_array( $paths ) ) {
$paths = array_map( 'FileBackend::normalizeStoragePath', $paths );
$paths = array_filter( $paths, 'strlen' ); // remove nulls
}
if ( $paths === null ) {
$this->cache = array();
$this->expensiveCache = array();
} else {
foreach ( $paths as $path ) {
unset( $this->cache[$path] );
unset( $this->expensiveCache[$path] );
}
}
$this->doClearCache( $paths );
}
/**
* Clears any additional stat caches for storage paths
*
* @see FileBackend::clearCache()
*
* @param $paths Array Storage paths (optional)
* @return void
*/
protected function doClearCache( array $paths = null ) {}
/**
* Prune the inexpensive cache if it is too big to add an item
*
* @return void
*/
protected function trimCache() {
if ( count( $this->cache ) >= $this->maxCacheSize ) {
reset( $this->cache );
unset( $this->cache[key( $this->cache )] );
}
}
/**
* Prune the expensive cache if it is too big to add an item
*
* @return void
*/
protected function trimExpensiveCache() {
if ( count( $this->expensiveCache ) >= $this->maxExpensiveCacheSize ) {
reset( $this->expensiveCache );
unset( $this->expensiveCache[key( $this->expensiveCache )] );
}
}
/**
* Check if a container name is valid.
* This checks for for length and illegal characters.
*
* @param $container string
* @return bool
*/
final protected static function isValidContainerName( $container ) {
// This accounts for Swift and S3 restrictions while leaving room
// for things like '.xxx' (hex shard chars) or '.seg' (segments).
// This disallows directory separators or traversal characters.
// Note that matching strings URL encode to the same string;
// in Swift, the length restriction is *after* URL encoding.
return preg_match( '/^[a-z0-9][a-z0-9-_]{0,199}$/i', $container );
}
/**
* Splits a storage path into an internal container name,
* an internal relative file name, and a container shard suffix.
* Any shard suffix is already appended to the internal container name.
* This also checks that the storage path is valid and within this backend.
*
* If the container is sharded but a suffix could not be determined,
* this means that the path can only refer to a directory and can only
* be scanned by looking in all the container shards.
*
* @param $storagePath string
* @return Array (container, path, container suffix) or (null, null, null) if invalid
*/
final protected function resolveStoragePath( $storagePath ) {
list( $backend, $container, $relPath ) = self::splitStoragePath( $storagePath );
if ( $backend === $this->name ) { // must be for this backend
$relPath = self::normalizeContainerPath( $relPath );
if ( $relPath !== null ) {
// Get shard for the normalized path if this container is sharded
$cShard = $this->getContainerShard( $container, $relPath );
// Validate and sanitize the relative path (backend-specific)
$relPath = $this->resolveContainerPath( $container, $relPath );
if ( $relPath !== null ) {
// Prepend any wiki ID prefix to the container name
$container = $this->fullContainerName( $container );
if ( self::isValidContainerName( $container ) ) {
// Validate and sanitize the container name (backend-specific)
$container = $this->resolveContainerName( "{$container}{$cShard}" );
if ( $container !== null ) {
return array( $container, $relPath, $cShard );
}
}
}
}
}
return array( null, null, null );
}
/**
* Like resolveStoragePath() except null values are returned if
* the container is sharded and the shard could not be determined.
*
* @see FileBackendStore::resolveStoragePath()
*
* @param $storagePath string
* @return Array (container, path) or (null, null) if invalid
*/
final protected function resolveStoragePathReal( $storagePath ) {
list( $container, $relPath, $cShard ) = $this->resolveStoragePath( $storagePath );
if ( $cShard !== null ) {
return array( $container, $relPath );
}
return array( null, null );
}
/**
* Get the container name shard suffix for a given path.
* Any empty suffix means the container is not sharded.
*
* @param $container string Container name
* @param $relStoragePath string Storage path relative to the container
* @return string|null Returns null if shard could not be determined
*/
final protected function getContainerShard( $container, $relPath ) {
list( $levels, $base, $repeat ) = $this->getContainerHashLevels( $container );
if ( $levels == 1 || $levels == 2 ) {
// Hash characters are either base 16 or 36
$char = ( $base == 36 ) ? '[0-9a-z]' : '[0-9a-f]';
// Get a regex that represents the shard portion of paths.
// The concatenation of the captures gives us the shard.
if ( $levels === 1 ) { // 16 or 36 shards per container
$hashDirRegex = '(' . $char . ')';
} else { // 256 or 1296 shards per container
if ( $repeat ) { // verbose hash dir format (e.g. "a/ab/abc")
$hashDirRegex = $char . '/(' . $char . '{2})';
} else { // short hash dir format (e.g. "a/b/c")
$hashDirRegex = '(' . $char . ')/(' . $char . ')';
}
}
// Allow certain directories to be above the hash dirs so as
// to work with FileRepo (e.g. "archive/a/ab" or "temp/a/ab").
// They must be 2+ chars to avoid any hash directory ambiguity.
$m = array();
if ( preg_match( "!^(?:[^/]{2,}/)*$hashDirRegex(?:/|$)!", $relPath, $m ) ) {
return '.' . implode( '', array_slice( $m, 1 ) );
}
return null; // failed to match
}
return ''; // no sharding
}
/**
* Get the sharding config for a container.
* If greater than 0, then all file storage paths within
* the container are required to be hashed accordingly.
*
* @param $container string
* @return Array (integer levels, integer base, repeat flag) or (0, 0, false)
*/
final protected function getContainerHashLevels( $container ) {
if ( isset( $this->shardViaHashLevels[$container] ) ) {
$config = $this->shardViaHashLevels[$container];
$hashLevels = (int)$config['levels'];
if ( $hashLevels == 1 || $hashLevels == 2 ) {
$hashBase = (int)$config['base'];
if ( $hashBase == 16 || $hashBase == 36 ) {
return array( $hashLevels, $hashBase, $config['repeat'] );
}
}
}
return array( 0, 0, false ); // no sharding
}
/**
* Get a list of full container shard suffixes for a container
*
* @param $container string
* @return Array
*/
final protected function getContainerSuffixes( $container ) {
$shards = array();
list( $digits, $base ) = $this->getContainerHashLevels( $container );
if ( $digits > 0 ) {
$numShards = pow( $base, $digits );
for ( $index = 0; $index < $numShards; $index++ ) {
$shards[] = '.' . wfBaseConvert( $index, 10, $base, $digits );
}
}
return $shards;
}
/**
* Get the full container name, including the wiki ID prefix
*
* @param $container string
* @return string
*/
final protected function fullContainerName( $container ) {
if ( $this->wikiId != '' ) {
return "{$this->wikiId}-$container";
} else {
return $container;
}
}
/**
* Resolve a container name, checking if it's allowed by the backend.
* This is intended for internal use, such as encoding illegal chars.
* Subclasses can override this to be more restrictive.
*
* @param $container string
* @return string|null
*/
protected function resolveContainerName( $container ) {
return $container;
}
/**
* Resolve a relative storage path, checking if it's allowed by the backend.
* This is intended for internal use, such as encoding illegal chars or perhaps
* getting absolute paths (e.g. FS based backends). Note that the relative path
* may be the empty string (e.g. the path is simply to the container).
*
* @param $container string Container name
* @param $relStoragePath string Storage path relative to the container
* @return string|null Path or null if not valid
*/
protected function resolveContainerPath( $container, $relStoragePath ) {
return $relStoragePath;
}
}
/**
* FileBackendStore helper function to handle file listings that span container shards.
* Do not use this class from places outside of FileBackendStore.
*
* @ingroup FileBackend
*/
class FileBackendStoreShardListIterator implements Iterator {
/* @var FileBackendStore */
protected $backend;
/* @var Array */
protected $params;
/* @var Array */
protected $shardSuffixes;
protected $container; // string
protected $directory; // string
/* @var Traversable */
protected $iter;
protected $curShard = 0; // integer
protected $pos = 0; // integer
/**
* @param $backend FileBackendStore
* @param $container string Full storage container name
* @param $dir string Storage directory relative to container
* @param $suffixes Array List of container shard suffixes
* @param $params Array
*/
public function __construct(
FileBackendStore $backend, $container, $dir, array $suffixes, array $params
) {
$this->backend = $backend;
$this->container = $container;
$this->directory = $dir;
$this->shardSuffixes = $suffixes;
$this->params = $params;
}
public function current() {
if ( is_array( $this->iter ) ) {
return current( $this->iter );
} else {
return $this->iter->current();
}
}
public function key() {
return $this->pos;
}
public function next() {
++$this->pos;
if ( is_array( $this->iter ) ) {
next( $this->iter );
} else {
$this->iter->next();
}
// Find the next non-empty shard if no elements are left
$this->nextShardIteratorIfNotValid();
}
/**
* If the iterator for this container shard is out of items,
* then move on to the next container that has items.
* If there are none, then it advances to the last container.
*/
protected function nextShardIteratorIfNotValid() {
while ( !$this->valid() ) {
if ( ++$this->curShard >= count( $this->shardSuffixes ) ) {
break; // no more container shards
}
$this->setIteratorFromCurrentShard();
}
}
protected function setIteratorFromCurrentShard() {
$suffix = $this->shardSuffixes[$this->curShard];
$this->iter = $this->backend->getFileListInternal(
"{$this->container}{$suffix}", $this->directory, $this->params );
}
public function rewind() {
$this->pos = 0;
$this->curShard = 0;
$this->setIteratorFromCurrentShard();
// Find the next non-empty shard if this one has no elements
$this->nextShardIteratorIfNotValid();
}
public function valid() {
if ( $this->iter == null ) {
return false; // some failure?
} elseif ( is_array( $this->iter ) ) {
return ( current( $this->iter ) !== false ); // no paths can have this value
} else {
return $this->iter->valid();
}
}
}