1 /*
2  * Copyright (C) 2023 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 android.adservices.ondevicepersonalization;
18 
19 import android.annotation.FlaggedApi;
20 import android.annotation.NonNull;
21 import android.annotation.Nullable;
22 import android.annotation.WorkerThread;
23 
24 import com.android.adservices.ondevicepersonalization.flags.Flags;
25 
26 import java.util.Set;
27 
28 /**
29  * An interface to a read-only key-value store.
30  *
31  * Used as a Data Access Object for the REMOTE_DATA table.
32  *
33  * @see IsolatedService#getRemoteData(RequestToken)
34  *
35  */
36 @FlaggedApi(Flags.FLAG_ON_DEVICE_PERSONALIZATION_APIS_ENABLED)
37 public interface KeyValueStore {
38     /**
39      * Looks up a key in a read-only store.
40      *
41      * @param key The key to look up.
42      * @return the value to which the specified key is mapped,
43      * or null if there contains no mapping for the key.
44      *
45      */
46     @WorkerThread
get(@onNull String key)47     @Nullable byte[] get(@NonNull String key);
48 
49     /**
50      * Returns a Set view of the keys contained in the REMOTE_DATA table.
51      */
52     @WorkerThread
keySet()53     @NonNull Set<String> keySet();
54 
55     /**
56      * Returns the table id {@link ModelId.TableId} of KeyValueStore implementation.
57      *
58      * @hide
59      */
getTableId()60     default int getTableId(){
61         return 0;
62     }
63 }
64