/*
* Copyright (C) 2011 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 com.android.email.provider;
import android.content.ContentResolver;
import android.content.Context;
/**
* Helper class to facilitate EmailProvider's account backup/restore facility.
*
* Account backup/restore was implemented entirely for the purpose of recovering from database
* corruption errors that were/are sporadic and of undetermined cause (though the prevailing wisdom
* is that this is due to some kind of memory issue). Rather than have the offending database get
* deleted by SQLiteDatabase and forcing the user to recreate his accounts from scratch, it was
* decided to backup accounts when created/modified and then restore them if 1) there are no
* accounts in the database and 2) there are backup accounts. This, at least, would cause user's
* email data for IMAP/EAS to be re-synced and prevent the worst outcomes from occurring.
*
* To accomplish backup/restore, we use the facility now built in to EmailProvider to store a
* backup version of the Account and HostAuth tables in a second database (EmailProviderBackup.db)
*
* TODO: We might look into having our own DatabaseErrorHandler that tries to be clever about
* determining whether or not a "corrupt" database is truly corrupt; the problem here is that it
* has proven impossible to reproduce the bug, and therefore any "solution" of this kind of utterly
* impossible to test in the wild.
*/
public class AccountBackupRestore {
/**
* Backup user Account and HostAuth data into our backup database
*
* TODO Make EmailProvider do this automatically.
*/
public static void backup(Context context) {
ContentResolver resolver = context.getContentResolver();
resolver.update(EmailProvider.ACCOUNT_BACKUP_URI, null, null, null);
}
}