FontLanguageListCache.cpp revision 6d9dcd2cf3d3ed26a886e02d94c907311e7b1f83 
1/*
2 * Copyright (C) 2015 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#define LOG_TAG "Minikin"
18
19#include "FontLanguageListCache.h"
20
21#include <cutils/log.h>
22
23#include "MinikinInternal.h"
24
25namespace android {
26
27const uint32_t FontLanguageListCache::kEmptyListId;
28
29// static
30uint32_t FontLanguageListCache::getId(const std::string& languages) {
31    FontLanguageListCache* inst = FontLanguageListCache::getInstance();
32    std::unordered_map<std::string, uint32_t>::const_iterator it =
33            inst->mLanguageListLookupTable.find(languages);
34    if (it != inst->mLanguageListLookupTable.end()) {
35        return it->second;
36    }
37
38    // Given language list is not in cache. Insert it and return newly assigned ID.
39    const uint32_t nextId = inst->mLanguageLists.size();
40    inst->mLanguageLists.push_back(FontLanguages(languages.c_str(), languages.size()));
41    inst->mLanguageListLookupTable.insert(std::make_pair(languages, nextId));
42    return nextId;
43}
44
45// static
46const FontLanguages& FontLanguageListCache::getById(uint32_t id) {
47    FontLanguageListCache* inst = FontLanguageListCache::getInstance();
48    LOG_ALWAYS_FATAL_IF(id >= inst->mLanguageLists.size(), "Lookup by unknown language list ID.");
49    return inst->mLanguageLists[id];
50}
51
52// static
53FontLanguageListCache* FontLanguageListCache::getInstance() {
54    assertMinikinLocked();
55    static FontLanguageListCache* instance = nullptr;
56    if (instance == nullptr) {
57        instance = new FontLanguageListCache();
58
59        // Insert an empty language list for mapping empty language list to kEmptyListId.
60        instance->mLanguageLists.push_back(FontLanguages());
61        instance->mLanguageListLookupTable.insert(std::make_pair("", kEmptyListId));
62    }
63    return instance;
64}
65
66}  // namespace android
67