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 "LocaleListCache.h"
20 
21 #include <unordered_set>
22 
23 #include <log/log.h>
24 #include <unicode/uloc.h>
25 
26 #include "Locale.h"
27 #include "MinikinInternal.h"
28 
29 namespace minikin {
30 
31 const uint32_t LocaleListCache::kEmptyListId;
32 
33 // Returns the text length of output.
toLanguageTag(char * output,size_t outSize,const StringPiece & locale)34 static size_t toLanguageTag(char* output, size_t outSize, const StringPiece& locale) {
35     output[0] = '\0';
36     if (locale.empty()) {
37         return 0;
38     }
39 
40     std::string localeString = locale.toString();  // ICU only understands C-style string.
41 
42     size_t outLength = 0;
43     UErrorCode uErr = U_ZERO_ERROR;
44     outLength = uloc_canonicalize(localeString.c_str(), output, outSize, &uErr);
45     if (U_FAILURE(uErr)) {
46         // unable to build a proper locale identifier
47         ALOGD("uloc_canonicalize(\"%s\") failed: %s", localeString.c_str(), u_errorName(uErr));
48         output[0] = '\0';
49         return 0;
50     }
51 
52     // Preserve "" and "_****" since uloc_addLikelySubtags changes "" to "en_Latn_US".
53     if (outLength == 0 || (outLength == 5 && output[0] == '_')) {
54         if (output[0] == '_') {
55             output[0] = '-';
56         }
57         std::string buf(output, outLength);
58         outLength = (size_t)snprintf(output, outSize, "und%s", buf.c_str());
59         return outLength;
60     }
61 
62     char likelyChars[ULOC_FULLNAME_CAPACITY];
63     uErr = U_ZERO_ERROR;
64     uloc_addLikelySubtags(output, likelyChars, ULOC_FULLNAME_CAPACITY, &uErr);
65     if (U_FAILURE(uErr)) {
66         // unable to build a proper locale identifier
67         ALOGD("uloc_addLikelySubtags(\"%s\") failed: %s", output, u_errorName(uErr));
68         output[0] = '\0';
69         return 0;
70     }
71 
72     uErr = U_ZERO_ERROR;
73     outLength = uloc_toLanguageTag(likelyChars, output, outSize, FALSE, &uErr);
74     if (U_FAILURE(uErr)) {
75         // unable to build a proper locale identifier
76         ALOGD("uloc_toLanguageTag(\"%s\") failed: %s", likelyChars, u_errorName(uErr));
77         output[0] = '\0';
78         return 0;
79     }
80     return outLength;
81 }
82 
parseLocaleList(const std::string & input)83 static std::vector<Locale> parseLocaleList(const std::string& input) {
84     std::vector<Locale> result;
85     char langTag[ULOC_FULLNAME_CAPACITY];
86     std::unordered_set<uint64_t> seen;
87 
88     SplitIterator it(input, ',');
89     while (it.hasNext()) {
90         StringPiece localeStr = it.next();
91         size_t length = toLanguageTag(langTag, ULOC_FULLNAME_CAPACITY, localeStr);
92         Locale locale(StringPiece(langTag, length));
93         if (locale.isUnsupported()) {
94             continue;
95         }
96         const bool isNewLocale = seen.insert(locale.getIdentifier()).second;
97         if (!isNewLocale) {
98             continue;
99         }
100 
101         result.push_back(locale);
102         if (result.size() >= FONT_LOCALE_LIMIT) {
103             break;
104         }
105     }
106     return result;
107 }
108 
LocaleListCache()109 LocaleListCache::LocaleListCache() {
110     // Insert an empty locale list for mapping default locale list to kEmptyListId.
111     // The default locale list has only one Locale and it is the unsupported locale.
112     mLocaleLists.emplace_back();
113     mLocaleListLookupTable.insert(std::make_pair("", kEmptyListId));
114 }
115 
getIdInternal(const std::string & locales)116 uint32_t LocaleListCache::getIdInternal(const std::string& locales) {
117     std::lock_guard<std::mutex> lock(mMutex);
118     const auto& it = mLocaleListLookupTable.find(locales);
119     if (it != mLocaleListLookupTable.end()) {
120         return it->second;
121     }
122 
123     // Given locale list is not in cache. Insert it and return newly assigned ID.
124     const uint32_t nextId = mLocaleLists.size();
125     LocaleList fontLocales(parseLocaleList(locales));
126     if (fontLocales.empty()) {
127         return kEmptyListId;
128     }
129     mLocaleLists.push_back(std::move(fontLocales));
130     mLocaleListLookupTable.insert(std::make_pair(locales, nextId));
131     return nextId;
132 }
133 
getByIdInternal(uint32_t id)134 const LocaleList& LocaleListCache::getByIdInternal(uint32_t id) {
135     std::lock_guard<std::mutex> lock(mMutex);
136     MINIKIN_ASSERT(id < mLocaleLists.size(), "Lookup by unknown locale list ID.");
137     return mLocaleLists[id];
138 }
139 
140 }  // namespace minikin
141