1/*
2 * Copyright 2018 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
17package androidx.work;
18
19import android.support.annotation.NonNull;
20
21import java.util.HashMap;
22import java.util.List;
23import java.util.Map;
24
25/**
26 * An {@link InputMerger} that attempts to add all keys from all inputs to the output.  In case of a
27 * conflict, this class will overwrite the previously-set key.  Because there is no defined order
28 * for inputs, this implementation is best suited for cases where conflicts will not happen, or
29 * where overwriting is a valid strategy to deal with them.
30 */
31
32public final class OverwritingInputMerger extends InputMerger {
33
34    @Override
35    public @NonNull Data merge(@NonNull List<Data> inputs) {
36        Data.Builder output = new Data.Builder();
37        Map<String, Object> mergedValues = new HashMap<>();
38
39        for (Data input : inputs) {
40            mergedValues.putAll(input.getKeyValueMap());
41        }
42
43        output.putAll(mergedValues);
44        return output.build();
45    }
46}
47