1/*
2 * Copyright (C) 2013 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#ifndef ANDROID_HWUI_TINYHASHMAP_H
18#define ANDROID_HWUI_TINYHASHMAP_H
19
20#include <utils/BasicHashtable.h>
21
22namespace android {
23namespace uirenderer {
24
25/**
26 * A very simple hash map that doesn't allow duplicate keys, overwriting the older entry.
27 */
28template <typename TKey, typename TValue>
29class TinyHashMap {
30public:
31    typedef key_value_pair_t<TKey, TValue> TEntry;
32
33    /**
34     * Puts an entry in the hash, removing any existing entry with the same key
35     */
36    void put(TKey key, TValue value) {
37        hash_t hash = android::hash_type(key);
38
39        ssize_t index = mTable.find(-1, hash, key);
40        if (index != -1) {
41            mTable.removeAt(index);
42        }
43
44        TEntry initEntry(key, value);
45        mTable.add(hash, initEntry);
46    }
47
48    /**
49     * Return true if key is in the map, in which case stores the value in the output ref
50     */
51    bool get(TKey key, TValue& outValue) {
52        hash_t hash = android::hash_type(key);
53        ssize_t index = mTable.find(-1, hash, key);
54        if (index == -1) {
55            return false;
56        }
57        outValue = mTable.entryAt(index).value;
58        return true;
59    }
60
61    void clear() { mTable.clear(); }
62
63private:
64    BasicHashtable<TKey, TEntry> mTable;
65};
66
67}; // namespace uirenderer
68}; // namespace android
69
70#endif // ANDROID_HWUI_TINYHASHMAP_H
71