xref: /aosp_15_r20/frameworks/minikin/libs/minikin/LocaleListCache.cpp (revision 834a2baab5fdfc28e9a428ee87c7ea8f6a06a53d)
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 #include "LocaleListCache.h"
18 
19 #include <unordered_set>
20 
21 #include <log/log.h>
22 #include <minikin/Hasher.h>
23 #include <minikin/LocaleList.h>
24 #include <unicode/uloc.h>
25 #include <unicode/umachine.h>
26 
27 #include "Locale.h"
28 #include "MinikinInternal.h"
29 
30 namespace minikin {
31 
32 // Returns the text length of output.
toLanguageTag(char * output,size_t outSize,const StringPiece & locale)33 static size_t toLanguageTag(char* output, size_t outSize, const StringPiece& locale) {
34     output[0] = '\0';
35     if (locale.empty()) {
36         return 0;
37     }
38 
39     std::string localeString = locale.toString();  // ICU only understands C-style string.
40 
41     size_t outLength = 0;
42     UErrorCode uErr = U_ZERO_ERROR;
43     outLength = uloc_canonicalize(localeString.c_str(), output, outSize, &uErr);
44     if (U_FAILURE(uErr) || (uErr == U_STRING_NOT_TERMINATED_WARNING)) {
45         // unable to build a proper locale identifier
46         ALOGD("uloc_canonicalize(\"%s\") failed: %s", localeString.c_str(), u_errorName(uErr));
47         output[0] = '\0';
48         return 0;
49     }
50 
51     // Preserve "" and "_****" since uloc_addLikelySubtags changes "" to "en_Latn_US".
52     if (outLength == 0 || (outLength == 5 && output[0] == '_')) {
53         if (output[0] == '_') {
54             output[0] = '-';
55         }
56         std::string buf(output, outLength);
57         outLength = (size_t)snprintf(output, outSize, "und%s", buf.c_str());
58         return outLength;
59     }
60 
61     char likelyChars[ULOC_FULLNAME_CAPACITY];
62     uErr = U_ZERO_ERROR;
63     uloc_addLikelySubtags(output, likelyChars, ULOC_FULLNAME_CAPACITY, &uErr);
64     if (U_FAILURE(uErr) || (uErr == U_STRING_NOT_TERMINATED_WARNING)) {
65         // unable to build a proper locale identifier
66         ALOGD("uloc_addLikelySubtags(\"%s\") failed: %s", output, u_errorName(uErr));
67         output[0] = '\0';
68         return 0;
69     }
70 
71     uErr = U_ZERO_ERROR;
72     outLength = uloc_toLanguageTag(likelyChars, output, outSize, false, &uErr);
73     if (U_FAILURE(uErr) || (uErr == U_STRING_NOT_TERMINATED_WARNING)) {
74         // unable to build a proper locale identifier
75         ALOGD("uloc_toLanguageTag(\"%s\") failed: %s", likelyChars, u_errorName(uErr));
76         output[0] = '\0';
77         return 0;
78     }
79     return outLength;
80 }
81 
parseLocaleList(const std::string & input)82 static std::vector<Locale> parseLocaleList(const std::string& input) {
83     std::vector<Locale> result;
84     char langTag[ULOC_FULLNAME_CAPACITY];
85     std::unordered_set<uint64_t> seen;
86 
87     SplitIterator it(input, ',');
88     while (it.hasNext()) {
89         StringPiece localeStr = it.next();
90         size_t length = toLanguageTag(langTag, ULOC_FULLNAME_CAPACITY, localeStr);
91         Locale locale(StringPiece(langTag, length));
92         if (locale.isUnsupported()) {
93             continue;
94         }
95         const bool isNewLocale = seen.insert(locale.getIdentifier()).second;
96         if (!isNewLocale) {
97             continue;
98         }
99 
100         result.push_back(locale);
101         if (result.size() >= FONT_LOCALE_LIMIT) {
102             break;
103         }
104     }
105     return result;
106 }
107 
operator ()(const std::vector<Locale> & locales) const108 size_t LocaleListCache::LocaleVectorHash::operator()(const std::vector<Locale>& locales) const {
109     Hasher hasher;
110     for (const auto& locale : locales) {
111         uint64_t id = locale.getIdentifier();
112         hasher.update(static_cast<uint32_t>((id >> 32) & 0xFFFFFFFF));
113         hasher.update(static_cast<uint32_t>(id & 0xFFFFFFFF));
114     }
115     return hasher.hash();
116 }
117 
LocaleListCache()118 LocaleListCache::LocaleListCache() {
119     // Insert an empty locale list for mapping default locale list to kEmptyLocaleListId.
120     // The default locale list has only one Locale and it is the unsupported locale.
121     mLocaleLists.emplace_back();
122     mLocaleListLookupTable.emplace(std::vector<Locale>(), kEmptyLocaleListId);
123     mLocaleListStringCache.emplace("", kEmptyLocaleListId);
124 }
125 
getIdInternal(const std::string & locales)126 uint32_t LocaleListCache::getIdInternal(const std::string& locales) {
127     std::lock_guard<std::mutex> lock(mMutex);
128     const auto& it = mLocaleListStringCache.find(locales);
129     if (it != mLocaleListStringCache.end()) {
130         return it->second;
131     }
132     uint32_t id = getIdInternal(parseLocaleList(locales));
133     mLocaleListStringCache.emplace(locales, id);
134     return id;
135 }
136 
getIdInternal(std::vector<Locale> && locales)137 uint32_t LocaleListCache::getIdInternal(std::vector<Locale>&& locales) {
138     if (locales.empty()) {
139         return kEmptyLocaleListId;
140     }
141     const auto& it = mLocaleListLookupTable.find(locales);
142     if (it != mLocaleListLookupTable.end()) {
143         return it->second;
144     }
145 
146     // Given locale list is not in cache. Insert it and return newly assigned ID.
147     const uint32_t nextId = mLocaleLists.size();
148     mLocaleListLookupTable.emplace(locales, nextId);
149     LocaleList fontLocales(std::move(locales));
150     mLocaleLists.push_back(std::move(fontLocales));
151     return nextId;
152 }
153 
readFromInternal(BufferReader * reader)154 uint32_t LocaleListCache::readFromInternal(BufferReader* reader) {
155     uint32_t size = reader->read<uint32_t>();
156     std::vector<Locale> locales;
157     locales.reserve(size);
158     for (uint32_t i = 0; i < size; i++) {
159         locales.emplace_back(reader->read<uint64_t>());
160     }
161     std::lock_guard<std::mutex> lock(mMutex);
162     return getIdInternal(std::move(locales));
163 }
164 
writeToInternal(BufferWriter * writer,uint32_t id)165 void LocaleListCache::writeToInternal(BufferWriter* writer, uint32_t id) {
166     const LocaleList& localeList = getByIdInternal(id);
167     writer->write<uint32_t>(localeList.size());
168     for (size_t i = 0; i < localeList.size(); i++) {
169         writer->write<uint64_t>(localeList[i].getIdentifier());
170     }
171 }
172 
getByIdInternal(uint32_t id)173 const LocaleList& LocaleListCache::getByIdInternal(uint32_t id) {
174     std::lock_guard<std::mutex> lock(mMutex);
175     MINIKIN_ASSERT(id < mLocaleLists.size(), "Lookup by unknown locale list ID.");
176     return mLocaleLists[id];
177 }
178 
179 }  // namespace minikin
180