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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.quicksearchbox.util;
     18 
     19 import android.database.sqlite.SQLiteDatabase;
     20 
     21 /**
     22  * Abstract helper base class for SQLite write transactions.
     23  */
     24 public abstract class SQLiteTransaction {
     25 
     26     /**
     27      * Executes the statements that form the transaction.
     28      *
     29      * @param db A writable database.
     30      * @return {@code true} if the transaction should be committed.
     31      */
     32     protected abstract boolean performTransaction(SQLiteDatabase db);
     33 
     34     /**
     35      * Runs the transaction against the database. The results are committed if
     36      * {@link #performTransaction(SQLiteDatabase)} completes normally and returns {@code true}.
     37      */
     38     public void run(SQLiteDatabase db) {
     39         db.beginTransaction();
     40         try {
     41             if (performTransaction(db)) {
     42                 db.setTransactionSuccessful();
     43             }
     44         } finally {
     45             db.endTransaction();
     46         }
     47     }
     48 }
     49