123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196 |
- // 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 STORAGE_BROWSER_FILE_SYSTEM_FILE_SYSTEM_BACKEND_H_
- #define STORAGE_BROWSER_FILE_SYSTEM_FILE_SYSTEM_BACKEND_H_
- #include <stdint.h>
- #include <limits>
- #include <memory>
- #include <string>
- #include <vector>
- #include "base/callback_forward.h"
- #include "base/component_export.h"
- #include "base/files/file.h"
- #include "base/files/file_path.h"
- #include "storage/browser/file_system/file_permission_policy.h"
- #include "storage/browser/file_system/open_file_system_mode.h"
- #include "storage/browser/file_system/task_runner_bound_observer_list.h"
- #include "storage/common/file_system/file_system_types.h"
- #include "url/origin.h"
- class GURL;
- namespace storage {
- class AsyncFileUtil;
- class CopyOrMoveFileValidatorFactory;
- class FileSystemURL;
- class FileStreamReader;
- class FileStreamWriter;
- class FileSystemContext;
- class FileSystemOperation;
- class FileSystemQuotaUtil;
- class WatcherManager;
- // Callback to take GURL.
- using URLCallback = base::OnceCallback<void(const GURL& url)>;
- // Maximum numer of bytes to be read by FileStreamReader classes. Used in
- // FileSystemBackend::CreateFileStreamReader(), when it's not known how many
- // bytes will be fetched in total.
- const int64_t kMaximumLength = INT64_MAX;
- // 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 COMPONENT_EXPORT(STORAGE_BROWSER) FileSystemBackend {
- public:
- // Callback for InitializeFileSystem.
- using OpenFileSystemCallback =
- base::OnceCallback<void(const FileSystemURL& root_url,
- const std::string& name,
- base::File::Error error)>;
- using ResolveURLCallback = base::OnceCallback<
- void(const GURL&, const std::string&, base::File::Error)>;
- virtual ~FileSystemBackend() = default;
- // 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,
- ResolveURLCallback callback) = 0;
- // Returns the specialized AsyncFileUtil for this backend.
- virtual AsyncFileUtil* GetAsyncFileUtil(FileSystemType type) = 0;
- // Returns the specialized WatcherManager for this backend.
- virtual WatcherManager* GetWatcherManager(FileSystemType type) = 0;
- // Returns the specialized CopyOrMoveFileValidatorFactory for this backend
- // and |type|. If |error_code| is File::FILE_OK and the result is nullptr,
- // 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 std::unique_ptr<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;
- // Returns true if specified |type| of filesystem can handle Copy()
- // of the files in the same file system instead of streaming
- // read/write implementation.
- virtual bool HasInplaceCopyImplementation(FileSystemType type) 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. At most |max_bytes_to_read| can be fetched from the file
- // stream reader.
- virtual std::unique_ptr<FileStreamReader> CreateFileStreamReader(
- const FileSystemURL& url,
- int64_t offset,
- int64_t max_bytes_to_read,
- 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 std::unique_ptr<FileStreamWriter> CreateFileStreamWriter(
- const FileSystemURL& url,
- int64_t offset,
- FileSystemContext* context) const = 0;
- // Returns the specialized FileSystemQuotaUtil for this backend.
- // This could return nullptr if this backend does not support quota.
- virtual FileSystemQuotaUtil* GetQuotaUtil() = 0;
- // Returns the update observer list for |type|. It may return nullptr when no
- // observers are added.
- virtual const UpdateObserverList* GetUpdateObservers(
- FileSystemType type) const = 0;
- // Returns the change observer list for |type|. It may return nullptr when no
- // observers are added.
- virtual const ChangeObserverList* GetChangeObservers(
- FileSystemType type) const = 0;
- // Returns the access observer list for |type|. It may return nullptr when no
- // observers are added.
- virtual const AccessObserverList* GetAccessObservers(
- FileSystemType type) const = 0;
- };
- // An interface to control external file system access permissions.
- // TODO(satorux): Move this out of 'storage/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 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 |virtual_path| from |origin| URL.
- virtual void GrantFileAccessToOrigin(const url::Origin& origin,
- const base::FilePath& virtual_path) = 0;
- // Revokes file access from origin identified with |origin|.
- virtual void RevokeAccessForOrigin(const url::Origin& origin) = 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) const = 0;
- // Gets a redirect URL for contents. e.g. Google Drive URL for hosted
- // documents. Returns empty URL if the entry does not have the redirect URL.
- virtual void GetRedirectURLForContents(const FileSystemURL& url,
- URLCallback callback) const = 0;
- // Creates an internal File System URL for performing internal operations such
- // as confirming if a file or a directory exist before granting the final
- // permission to the entry. The path must be an absolute path.
- virtual FileSystemURL CreateInternalURL(
- FileSystemContext* context,
- const base::FilePath& entry_path) const = 0;
- };
- } // namespace storage
- #endif // STORAGE_BROWSER_FILE_SYSTEM_FILE_SYSTEM_BACKEND_H_
|