// Copyright (c) 2012 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef WEBKIT_BROWSER_FILEAPI_FILE_SYSTEM_BACKEND_H_ #define WEBKIT_BROWSER_FILEAPI_FILE_SYSTEM_BACKEND_H_ #include <string> #include <vector> #include "base/callback_forward.h" #include "base/files/file.h" #include "base/files/file_path.h" #include "base/memory/scoped_ptr.h" #include "webkit/browser/fileapi/file_permission_policy.h" #include "webkit/browser/fileapi/open_file_system_mode.h" #include "webkit/browser/webkit_storage_browser_export.h" #include "webkit/common/fileapi/file_system_types.h" class GURL; namespace webkit_blob { class FileStreamReader; } namespace fileapi { class AsyncFileUtil; class CopyOrMoveFileValidatorFactory; class FileSystemURL; class FileStreamWriter; class FileSystemContext; class FileSystemFileUtil; class FileSystemOperation; class FileSystemQuotaUtil; // An interface for defining a file system backend. // // NOTE: when you implement a new FileSystemBackend for your own // FileSystem module, please contact to kinuko@chromium.org. // class WEBKIT_STORAGE_BROWSER_EXPORT FileSystemBackend { public: // Callback for InitializeFileSystem. typedef base::Callback<void(const GURL& root_url, const std::string& name, base::File::Error error)> OpenFileSystemCallback; virtual ~FileSystemBackend() {} // Returns true if this filesystem backend can handle |type|. // One filesystem backend may be able to handle multiple filesystem types. virtual bool CanHandleType(FileSystemType type) const = 0; // This method is called right after the backend is registered in the // FileSystemContext and before any other methods are called. Each backend can // do additional initialization which depends on FileSystemContext here. virtual void Initialize(FileSystemContext* context) = 0; // Resolves the filesystem root URL and the name for the given |url|. // This verifies if it is allowed to request (or create) the filesystem and if // it can access (or create) the root directory. // If |mode| is CREATE_IF_NONEXISTENT calling this may also create the root // directory (and/or related database entries etc) for the filesystem if it // doesn't exist. virtual void ResolveURL(const FileSystemURL& url, OpenFileSystemMode mode, const OpenFileSystemCallback& callback) = 0; // Returns the specialized AsyncFileUtil for this backend. virtual AsyncFileUtil* GetAsyncFileUtil(FileSystemType type) = 0; // Returns the specialized CopyOrMoveFileValidatorFactory for this backend // and |type|. If |error_code| is PLATFORM_FILE_OK and the result is NULL, // then no validator is required. virtual CopyOrMoveFileValidatorFactory* GetCopyOrMoveFileValidatorFactory( FileSystemType type, base::File::Error* error_code) = 0; // Returns a new instance of the specialized FileSystemOperation for this // backend based on the given triplet of |origin_url|, |file_system_type| // and |virtual_path|. On failure to create a file system operation, set // |error_code| correspondingly. // This method is usually dispatched by // FileSystemContext::CreateFileSystemOperation. virtual FileSystemOperation* CreateFileSystemOperation( const FileSystemURL& url, FileSystemContext* context, base::File::Error* error_code) const = 0; // Returns true if Blobs accessing |url| should use FileStreamReader. // If false, Blobs are accessed using a snapshot file by calling // AsyncFileUtil::CreateSnapshotFile. virtual bool SupportsStreaming(const FileSystemURL& url) const = 0; // Creates a new file stream reader for a given filesystem URL |url| with an // offset |offset|. |expected_modification_time| specifies the expected last // modification if the value is non-null, the reader will check the underlying // file's actual modification time to see if the file has been modified, and // if it does any succeeding read operations should fail with // ERR_UPLOAD_FILE_CHANGED error. // This method itself does *not* check if the given path exists and is a // regular file. virtual scoped_ptr<webkit_blob::FileStreamReader> CreateFileStreamReader( const FileSystemURL& url, int64 offset, const base::Time& expected_modification_time, FileSystemContext* context) const = 0; // Creates a new file stream writer for a given filesystem URL |url| with an // offset |offset|. // This method itself does *not* check if the given path exists and is a // regular file. virtual scoped_ptr<FileStreamWriter> CreateFileStreamWriter( const FileSystemURL& url, int64 offset, FileSystemContext* context) const = 0; // Returns the specialized FileSystemQuotaUtil for this backend. // This could return NULL if this backend does not support quota. virtual FileSystemQuotaUtil* GetQuotaUtil() = 0; }; // An interface to control external file system access permissions. // TODO(satorux): Move this out of 'webkit/browser/fileapi'. crbug.com/257279 class ExternalFileSystemBackend : public FileSystemBackend { public: // Returns true if |url| is allowed to be accessed. // This is supposed to perform ExternalFileSystem-specific security // checks. virtual bool IsAccessAllowed(const fileapi::FileSystemURL& url) const = 0; // Returns the list of top level directories that are exposed by this // provider. This list is used to set appropriate child process file access // permissions. virtual std::vector<base::FilePath> GetRootDirectories() const = 0; // Grants access to all external file system from extension identified with // |extension_id|. virtual void GrantFullAccessToExtension(const std::string& extension_id) = 0; // Grants access to |virtual_path| from |origin_url|. virtual void GrantFileAccessToExtension( const std::string& extension_id, const base::FilePath& virtual_path) = 0; // Revokes file access from extension identified with |extension_id|. virtual void RevokeAccessForExtension( const std::string& extension_id) = 0; // Gets virtual path by known filesystem path. Returns false when filesystem // path is not exposed by this provider. virtual bool GetVirtualPath(const base::FilePath& file_system_path, base::FilePath* virtual_path) = 0; }; } // namespace fileapi #endif // WEBKIT_BROWSER_FILEAPI_FILE_SYSTEM_BACKEND_H_