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Diffstat (limited to 'includes/filerepo/backend/FileBackend.php')
| -rw-r--r-- | includes/filerepo/backend/FileBackend.php | 1739 |
1 files changed, 0 insertions, 1739 deletions
diff --git a/includes/filerepo/backend/FileBackend.php b/includes/filerepo/backend/FileBackend.php deleted file mode 100644 index 9433bcb4..00000000 --- a/includes/filerepo/backend/FileBackend.php +++ /dev/null @@ -1,1739 +0,0 @@ -<?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(); - } - } -} |