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 "und" and "und-****" since uloc_addLikelySubtags changes "und" to "en-Latn-US".
53     if (strncmp(output, "und", 3) == 0 &&
54         (outLength == 3 || (outLength == 8 && output[3] == '_'))) {
55         output[3] = '-';  // to be language tag.
56         return outLength;
57     }
58 
59     char likelyChars[ULOC_FULLNAME_CAPACITY];
60     uErr = U_ZERO_ERROR;
61     uloc_addLikelySubtags(output, likelyChars, ULOC_FULLNAME_CAPACITY, &uErr);
62     if (U_FAILURE(uErr)) {
63         // unable to build a proper locale identifier
64         ALOGD("uloc_addLikelySubtags(\"%s\") failed: %s", output, u_errorName(uErr));
65         output[0] = '\0';
66         return 0;
67     }
68 
69     uErr = U_ZERO_ERROR;
70     outLength = uloc_toLanguageTag(likelyChars, output, outSize, FALSE, &uErr);
71     if (U_FAILURE(uErr)) {
72         // unable to build a proper locale identifier
73         ALOGD("uloc_toLanguageTag(\"%s\") failed: %s", likelyChars, u_errorName(uErr));
74         output[0] = '\0';
75         return 0;
76     }
77     return outLength;
78 }
79 
parseLocaleList(const std::string & input)80 static std::vector<Locale> parseLocaleList(const std::string& input) {
81     std::vector<Locale> result;
82     char langTag[ULOC_FULLNAME_CAPACITY];
83     std::unordered_set<uint64_t> seen;
84 
85     SplitIterator it(input, ',');
86     while (it.hasNext()) {
87         StringPiece localeStr = it.next();
88         size_t length = toLanguageTag(langTag, ULOC_FULLNAME_CAPACITY, localeStr);
89         Locale locale(StringPiece(langTag, length));
90         if (locale.isUnsupported()) {
91             continue;
92         }
93         const bool isNewLocale = seen.insert(locale.getIdentifier()).second;
94         if (!isNewLocale) {
95             continue;
96         }
97 
98         result.push_back(locale);
99         if (result.size() >= FONT_LOCALE_LIMIT) {
100             break;
101         }
102     }
103     return result;
104 }
105 
LocaleListCache()106 LocaleListCache::LocaleListCache() {
107     // Insert an empty locale list for mapping default locale list to kEmptyListId.
108     // The default locale list has only one Locale and it is the unsupported locale.
109     mLocaleLists.emplace_back();
110     mLocaleListLookupTable.insert(std::make_pair("", kEmptyListId));
111 }
112 
getIdInternal(const std::string & locales)113 uint32_t LocaleListCache::getIdInternal(const std::string& locales) {
114     std::lock_guard<std::mutex> lock(mMutex);
115     const auto& it = mLocaleListLookupTable.find(locales);
116     if (it != mLocaleListLookupTable.end()) {
117         return it->second;
118     }
119 
120     // Given locale list is not in cache. Insert it and return newly assigned ID.
121     const uint32_t nextId = mLocaleLists.size();
122     LocaleList fontLocales(parseLocaleList(locales));
123     if (fontLocales.empty()) {
124         return kEmptyListId;
125     }
126     mLocaleLists.push_back(std::move(fontLocales));
127     mLocaleListLookupTable.insert(std::make_pair(locales, nextId));
128     return nextId;
129 }
130 
getByIdInternal(uint32_t id)131 const LocaleList& LocaleListCache::getByIdInternal(uint32_t id) {
132     std::lock_guard<std::mutex> lock(mMutex);
133     MINIKIN_ASSERT(id < mLocaleLists.size(), "Lookup by unknown locale list ID.");
134     return mLocaleLists[id];
135 }
136 
137 }  // namespace minikin
138