// 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 CHROME_BROWSER_SYNC_FILE_SYSTEM_REMOTE_CHANGE_PROCESSOR_H_
#define CHROME_BROWSER_SYNC_FILE_SYSTEM_REMOTE_CHANGE_PROCESSOR_H_
#include "base/basictypes.h"
#include "base/callback_forward.h"
#include "chrome/browser/sync_file_system/sync_callbacks.h"
#include "chrome/browser/sync_file_system/sync_status_code.h"
namespace base {
class FilePath;
}
namespace fileapi {
class FileSystemURL;
}
namespace sync_file_system {
class FileChange;
class FileChangeList;
class SyncFileMetadata;
// Represents an interface to process one remote change and applies
// it to the local file system.
// This interface is to be implemented/backed by LocalSyncFileService.
class RemoteChangeProcessor {
public:
// Callback type for PrepareForProcessRemoteChange.
// |file_type| indicates the current file/directory type of the target
// URL in the local filesystem. If the target URL does not exist it is
// set to SYNC_FILE_TYPE_UNKNOWN.
// |changes| indicates a set of pending changes for the target URL.
typedef base::Callback<void(
SyncStatusCode status,
const SyncFileMetadata& metadata,
const FileChangeList& changes)> PrepareChangeCallback;
RemoteChangeProcessor() {}
virtual ~RemoteChangeProcessor() {}
// This must be called before processing the change for the |url|.
// This tries to lock the target |url| and returns the local changes
// if any. (The change returned by the callback is to make a decision
// on conflict resolution, but NOT for applying local changes to the remote,
// which is supposed to be done by LocalChangeProcessor)
virtual void PrepareForProcessRemoteChange(
const fileapi::FileSystemURL& url,
const PrepareChangeCallback& callback) = 0;
// This is called to apply the remote |change|. If the change type is
// ADD_OR_UPDATE for a file, |local_path| needs to point to a
// local file path that contains the latest file image (e.g. a path
// to a temporary file which has the data downloaded from the server).
// This may fail with an error but should NOT result in a conflict
// (as we must have checked the change status in PrepareRemoteSync and
// have disabled any further writing).
virtual void ApplyRemoteChange(
const FileChange& change,
const base::FilePath& local_path,
const fileapi::FileSystemURL& url,
const SyncStatusCallback& callback) = 0;
// Finalizes the remote sync started by PrepareForProcessRemoteChange.
// This clears sync flag on |url| to unlock the file for future writes/sync.
// Clears all local changes if |clear_local_changes| is true.
// This should be set to true when the remote sync service reconciled or
// processed the existing local changes while processing a remote change.
virtual void FinalizeRemoteSync(
const fileapi::FileSystemURL& url,
bool clear_local_changes,
const base::Closure& completion_callback) = 0;
// Records a fake local change so that the change will be processed in the
// next local sync.
// This is called when the remote side wants to trigger a local sync
// to propagate the local change to the remote change (e.g. to
// resolve a conflict by uploading the local file).
virtual void RecordFakeLocalChange(
const fileapi::FileSystemURL& url,
const FileChange& change,
const SyncStatusCallback& callback) = 0;
private:
DISALLOW_COPY_AND_ASSIGN(RemoteChangeProcessor);
};
} // namespace sync_file_system
#endif // CHROME_BROWSER_SYNC_FILE_SYSTEM_REMOTE_CHANGE_PROCESSOR_H_