1 /* 2 * Copyright (C) 2022 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.adservices.data.adselection; 18 19 import android.content.Context; 20 21 import androidx.annotation.NonNull; 22 import androidx.room.AutoMigration; 23 import androidx.room.Database; 24 import androidx.room.Room; 25 import androidx.room.RoomDatabase; 26 import androidx.room.TypeConverters; 27 28 import com.android.adservices.data.common.FledgeRoomConverters; 29 30 import java.util.Objects; 31 32 /** Room based database for cross-app data that is read from during ad selection */ 33 @Database( 34 entities = { 35 DBAppInstallPermissions.class, 36 DBHistogramEventData.class, 37 DBHistogramIdentifier.class, 38 }, 39 version = SharedStorageDatabase.DATABASE_VERSION, 40 autoMigrations = {@AutoMigration(from = 1, to = 2)}) 41 @TypeConverters({FledgeRoomConverters.class}) 42 public abstract class SharedStorageDatabase extends RoomDatabase { 43 private static final Object SINGLETON_LOCK = new Object(); 44 45 public static final int DATABASE_VERSION = 2; 46 public static final String DATABASE_NAME = "sharedstorage.db"; 47 static final Long FOREIGN_KEY_AUTOGENERATE_SUBSTITUTE = null; 48 49 private static volatile SharedStorageDatabase sSingleton = null; 50 51 /** Returns or creates the instance of SharedStorageDatabase given a context. */ getInstance(@onNull Context context)52 public static SharedStorageDatabase getInstance(@NonNull Context context) { 53 Objects.requireNonNull(context, "Context must be provided."); 54 // Initialization pattern recommended on page 334 of "Effective Java" 3rd edition 55 SharedStorageDatabase singleReadResult = sSingleton; 56 if (singleReadResult != null) { 57 return singleReadResult; 58 } 59 synchronized (SINGLETON_LOCK) { 60 if (sSingleton == null) { 61 sSingleton = 62 Room.databaseBuilder(context, SharedStorageDatabase.class, DATABASE_NAME) 63 .fallbackToDestructiveMigration() 64 .build(); 65 } 66 return sSingleton; 67 } 68 } 69 70 /** @return a Dao to run queries for app install */ appInstallDao()71 public abstract AppInstallDao appInstallDao(); 72 73 /** @return a DAO for interfacing with ad event histograms and their overrides */ frequencyCapDao()74 public abstract FrequencyCapDao frequencyCapDao(); 75 } 76