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      1 /*
      2  * Copyright (C) 2007 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.common.content;
     18 
     19 import android.accounts.Account;
     20 import android.content.ContentValues;
     21 import android.database.Cursor;
     22 import android.database.DatabaseUtils;
     23 import android.database.sqlite.SQLiteDatabase;
     24 import android.provider.SyncStateContract;
     25 
     26 /**
     27  * Extends the schema of a ContentProvider to include the _sync_state table
     28  * and implements query/insert/update/delete to access that table using the
     29  * authority "syncstate". This can be used to store the sync state for a
     30  * set of accounts.
     31  */
     32 public class SyncStateContentProviderHelper {
     33     private static final String SELECT_BY_ACCOUNT =
     34             SyncStateContract.Columns.ACCOUNT_NAME + "=? AND "
     35                     + SyncStateContract.Columns.ACCOUNT_TYPE + "=?";
     36 
     37     private static final String SYNC_STATE_TABLE = "_sync_state";
     38     private static final String SYNC_STATE_META_TABLE = "_sync_state_metadata";
     39     private static final String SYNC_STATE_META_VERSION_COLUMN = "version";
     40 
     41     private static long DB_VERSION = 1;
     42 
     43     private static final String[] ACCOUNT_PROJECTION =
     44             new String[]{SyncStateContract.Columns.ACCOUNT_NAME,
     45                     SyncStateContract.Columns.ACCOUNT_TYPE};
     46 
     47     public static final String PATH = "syncstate";
     48 
     49     private static final String QUERY_COUNT_SYNC_STATE_ROWS =
     50             "SELECT count(*)"
     51                     + " FROM " + SYNC_STATE_TABLE
     52                     + " WHERE " + SyncStateContract.Columns._ID + "=?";
     53 
     54     public void createDatabase(SQLiteDatabase db) {
     55         db.execSQL("DROP TABLE IF EXISTS " + SYNC_STATE_TABLE);
     56         db.execSQL("CREATE TABLE " + SYNC_STATE_TABLE + " ("
     57                 + SyncStateContract.Columns._ID + " INTEGER PRIMARY KEY,"
     58                 + SyncStateContract.Columns.ACCOUNT_NAME + " TEXT NOT NULL,"
     59                 + SyncStateContract.Columns.ACCOUNT_TYPE + " TEXT NOT NULL,"
     60                 + SyncStateContract.Columns.DATA + " TEXT,"
     61                 + "UNIQUE(" + SyncStateContract.Columns.ACCOUNT_NAME + ", "
     62                 + SyncStateContract.Columns.ACCOUNT_TYPE + "));");
     63 
     64         db.execSQL("DROP TABLE IF EXISTS " + SYNC_STATE_META_TABLE);
     65         db.execSQL("CREATE TABLE " + SYNC_STATE_META_TABLE + " ("
     66                 + SYNC_STATE_META_VERSION_COLUMN + " INTEGER);");
     67         ContentValues values = new ContentValues();
     68         values.put(SYNC_STATE_META_VERSION_COLUMN, DB_VERSION);
     69         db.insert(SYNC_STATE_META_TABLE, SYNC_STATE_META_VERSION_COLUMN, values);
     70     }
     71 
     72     public void onDatabaseOpened(SQLiteDatabase db) {
     73         long version = DatabaseUtils.longForQuery(db,
     74                 "SELECT " + SYNC_STATE_META_VERSION_COLUMN + " FROM " + SYNC_STATE_META_TABLE,
     75                 null);
     76         if (version != DB_VERSION) {
     77             createDatabase(db);
     78         }
     79     }
     80 
     81     public Cursor query(SQLiteDatabase db, String[] projection,
     82             String selection, String[] selectionArgs, String sortOrder) {
     83         return db.query(SYNC_STATE_TABLE, projection, selection, selectionArgs,
     84                 null, null, sortOrder);
     85     }
     86 
     87     public long insert(SQLiteDatabase db, ContentValues values) {
     88         return db.replace(SYNC_STATE_TABLE, SyncStateContract.Columns.ACCOUNT_NAME, values);
     89     }
     90 
     91     public int delete(SQLiteDatabase db, String userWhere, String[] whereArgs) {
     92         return db.delete(SYNC_STATE_TABLE, userWhere, whereArgs);
     93     }
     94 
     95     public int update(SQLiteDatabase db, ContentValues values,
     96             String selection, String[] selectionArgs) {
     97         return db.update(SYNC_STATE_TABLE, values, selection, selectionArgs);
     98     }
     99 
    100     public int update(SQLiteDatabase db, long rowId, Object data) {
    101         if (DatabaseUtils.longForQuery(db, QUERY_COUNT_SYNC_STATE_ROWS,
    102                 new String[]{Long.toString(rowId)}) < 1) {
    103             return 0;
    104         }
    105         db.execSQL("UPDATE " + SYNC_STATE_TABLE
    106                 + " SET " + SyncStateContract.Columns.DATA + "=?"
    107                 + " WHERE " + SyncStateContract.Columns._ID + "=" + rowId,
    108                 new Object[]{data});
    109         // assume a row was modified since we know it exists
    110         return 1;
    111     }
    112 
    113     public void onAccountsChanged(SQLiteDatabase db, Account[] accounts) {
    114         Cursor c = db.query(SYNC_STATE_TABLE, ACCOUNT_PROJECTION, null, null, null, null, null);
    115         try {
    116             while (c.moveToNext()) {
    117                 final String accountName = c.getString(0);
    118                 final String accountType = c.getString(1);
    119                 Account account = new Account(accountName, accountType);
    120                 if (!contains(accounts, account)) {
    121                     db.delete(SYNC_STATE_TABLE, SELECT_BY_ACCOUNT,
    122                             new String[]{accountName, accountType});
    123                 }
    124             }
    125         } finally {
    126             c.close();
    127         }
    128     }
    129 
    130     /**
    131      * Checks that value is present as at least one of the elements of the array.
    132      * @param array the array to check in
    133      * @param value the value to check for
    134      * @return true if the value is present in the array
    135      */
    136     private static <T> boolean contains(T[] array, T value) {
    137         for (T element : array) {
    138             if (element == null) {
    139                 if (value == null) return true;
    140             } else {
    141                 if (value != null && element.equals(value)) return true;
    142             }
    143         }
    144         return false;
    145     }
    146 }