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.RoomDatabase;
25 import androidx.room.TypeConverters;
26 
27 import com.android.adservices.data.common.FledgeRoomConverters;
28 import com.android.adservices.service.common.compat.FileCompatUtils;
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), @AutoMigration(from = 2, to = 3)})
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 = 3;
46     public static final String DATABASE_NAME =
47             FileCompatUtils.getAdservicesFilename("sharedstorage.db");
48     static final Long FOREIGN_KEY_AUTOGENERATE_SUBSTITUTE = null;
49 
50     private static volatile SharedStorageDatabase sSingleton = null;
51 
52     /** Returns or creates the instance of SharedStorageDatabase given a context. */
getInstance(@onNull Context context)53     public static SharedStorageDatabase getInstance(@NonNull Context context) {
54         Objects.requireNonNull(context, "Context must be provided.");
55         // Initialization pattern recommended on page 334 of "Effective Java" 3rd edition
56         SharedStorageDatabase singleReadResult = sSingleton;
57         if (singleReadResult != null) {
58             return singleReadResult;
59         }
60         synchronized (SINGLETON_LOCK) {
61             if (sSingleton == null) {
62                 sSingleton =
63                         FileCompatUtils.roomDatabaseBuilderHelper(
64                                         context, SharedStorageDatabase.class, DATABASE_NAME)
65                                 .fallbackToDestructiveMigration()
66                                 .build();
67             }
68             return sSingleton;
69         }
70     }
71 
72     /** @return a Dao to run queries for app install */
appInstallDao()73     public abstract AppInstallDao appInstallDao();
74 
75     /** @return a DAO for interfacing with ad event histograms and their overrides */
frequencyCapDao()76     public abstract FrequencyCapDao frequencyCapDao();
77 }
78