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.service.common.cache;
18 
19 import static com.android.adservices.service.common.cache.CacheDatabase.DATABASE_VERSION;
20 
21 import android.content.Context;
22 
23 import androidx.annotation.NonNull;
24 import androidx.room.AutoMigration;
25 import androidx.room.Database;
26 import androidx.room.RoomDatabase;
27 import androidx.room.TypeConverters;
28 
29 import com.android.adservices.data.common.FledgeRoomConverters;
30 import com.android.adservices.service.common.compat.FileCompatUtils;
31 import com.android.internal.annotations.GuardedBy;
32 
33 import java.util.Objects;
34 
35 /** A class that represents the database for caching web requests related to Fledge */
36 @Database(
37         entities = {DBCacheEntry.class},
38         autoMigrations = {
39             @AutoMigration(from = 1, to = 2),
40         },
41         version = DATABASE_VERSION)
42 @TypeConverters({FledgeRoomConverters.class})
43 public abstract class CacheDatabase extends RoomDatabase {
44     private static final Object SINGLETON_LOCK = new Object();
45 
46     // TODO(b/270615351): Create migration rollback test for version bump
47     public static final int DATABASE_VERSION = 2;
48     public static final String DATABASE_NAME =
49             FileCompatUtils.getAdservicesFilename("fledgehttpcache.db");
50 
51     @GuardedBy("SINGLETON_LOCK")
52     private static CacheDatabase sSingleton = null;
53 
54     /** Returns an instance of the CacheDatabase given a context. */
getInstance(@onNull Context context)55     public static CacheDatabase getInstance(@NonNull Context context) {
56         Objects.requireNonNull(context);
57         synchronized (SINGLETON_LOCK) {
58             if (Objects.isNull(sSingleton)) {
59                 sSingleton =
60                         FileCompatUtils.roomDatabaseBuilderHelper(
61                                         context, CacheDatabase.class, DATABASE_NAME)
62                                 .fallbackToDestructiveMigration()
63                                 .build();
64             }
65             return sSingleton;
66         }
67     }
68 
69     /** @return a Dao to access cached entries */
getCacheEntryDao()70     public abstract CacheEntryDao getCacheEntryDao();
71 }
72