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/*
* Copyright (C) 2009 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.backup;
import android.annotation.SdkConstant;
import android.annotation.SdkConstant.SdkConstantType;
import android.app.Service;
import android.backup.IBackupService;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;
/**
* This is the central interface between an application and Android's
* settings backup mechanism.
*
* <p><em>Not hidden but API subject to change and should not be published</em>
*/
public abstract class BackupService extends Service {
/**
* Service Action: Participate in the backup infrastructure. Applications
* that wish to use the Android backup mechanism must provide an exported
* subclass of BackupService and give it an {@link android.content.IntentFilter
* IntentFilter} that accepts this action.
*/
@SdkConstant(SdkConstantType.SERVICE_ACTION)
public static final String SERVICE_ACTION = "android.service.action.BACKUP";
/**
* The application is being asked to write any data changed since the
* last time it performed a backup operation. The state data recorded
* during the last backup pass is provided in the oldStateFd file descriptor.
* If oldStateFd is negative, no old state is available and the application
* should perform a full backup. In both cases, a representation of the
* final backup state after this pass should be written to the file pointed
* to by the newStateFd file descriptor.
*
* @param oldStateFd An open, read-only file descriptor pointing to the last
* backup state provided by the application. May be negative,
* in which case no prior state is being provided and the
* application should perform a full backup.
* @param dataFd An open, read/write file descriptor pointing to the backup data
* destination. Typically the application will use backup helper
* classes to write to this file.
* @param newStateFd An open, read/write file descriptor pointing to an empty
* file. The application should record the final backup state
* here after writing the requested data to dataFd.
*/
public abstract void onBackup(int oldStateFd, int dataFd, int newStateFd);
/**
* The application is being restored from backup, and should replace any
* existing data with the contents of the backup. The backup data is
* provided in the file pointed to by the dataFd file descriptor. Once
* the restore is finished, the application should write a representation
* of the final state to the newStateFd file descriptor,
*
* @param dataFd An open, read-only file descriptor pointing to a full snapshot
* of the application's data.
* @param newStateFd An open, read/write file descriptor pointing to an empty
* file. The application should record the final backup state
* here after restoring its data from dataFd.
*/
public abstract void onRestore(int dataFd, int newStateFd);
// ----- Core implementation -----
public IBinder onBind(Intent intent) {
return mBinder;
}
private final IBinder mBinder = new BackupServiceBinder().asBinder();
// ----- IBackupService binder interface -----
private class BackupServiceBinder extends IBackupService.Stub {
public void doBackup(int oldStateFd, int dataFd, int newStateFd)
throws RemoteException {
// !!! TODO - real implementation; for now just invoke the callbacks directly
Log.v("BackupServiceBinder", "doBackup() invoked");
BackupService.this.onBackup(oldStateFd, dataFd, newStateFd);
}
public void doRestore(int dataFd, int newStateFd) throws RemoteException {
// !!! TODO - real implementation; for now just invoke the callbacks directly
Log.v("BackupServiceBinder", "doRestore() invoked");
BackupService.this.onRestore(dataFd, newStateFd);
}
}
}
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