1/*
2 * Copyright (C) 2016 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 */
16package com.android.car.hal;
17
18import android.util.SparseIntArray;
19
20/**
21 * Helper class that maintains bi-directional mapping between int values.
22 *
23 * <p>This class is immutable. Use {@link #create(int[])} factory method to instantiate this class.
24 */
25class BidirectionalSparseIntArray {
26    private final SparseIntArray mMap;
27    private final SparseIntArray mInverseMap;
28
29    /**
30     * Creates {@link BidirectionalSparseIntArray} for provided int pairs.
31     *
32     * <p> The input array should have an even number of elements.
33     */
34    static BidirectionalSparseIntArray create(int[] keyValuePairs) {
35        int inputLength = keyValuePairs.length;
36        if (inputLength % 2 != 0) {
37            throw new IllegalArgumentException("Odd number of key-value elements");
38        }
39
40        BidirectionalSparseIntArray biMap = new BidirectionalSparseIntArray(inputLength / 2);
41        for (int i = 0; i < keyValuePairs.length; i += 2) {
42            biMap.put(keyValuePairs[i], keyValuePairs[i + 1]);
43        }
44        return biMap;
45    }
46
47    private BidirectionalSparseIntArray(int initialCapacity) {
48        mMap = new SparseIntArray(initialCapacity);
49        mInverseMap = new SparseIntArray(initialCapacity);
50    }
51
52    private void put(int key, int value) {
53        mMap.put(key, value);
54        mInverseMap.put(value, key);
55    }
56
57    int getValue(int key, int defaultValue) {
58        return mMap.get(key, defaultValue);
59    }
60
61    int getKey(int value, int defaultKey) {
62        return mInverseMap.get(value, defaultKey);
63    }
64}
65