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[chromium-blink-merge.git] / base / strings / sys_string_conversions_posix.cc
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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "base/strings/sys_string_conversions.h"
7 #include <wchar.h>
9 #include "base/strings/string_piece.h"
10 #include "base/strings/utf_string_conversions.h"
12 namespace base {
14 std::string SysWideToUTF8(const std::wstring& wide) {
15 // In theory this should be using the system-provided conversion rather
16 // than our ICU, but this will do for now.
17 return WideToUTF8(wide);
19 std::wstring SysUTF8ToWide(const StringPiece& utf8) {
20 // In theory this should be using the system-provided conversion rather
21 // than our ICU, but this will do for now.
22 std::wstring out;
23 UTF8ToWide(utf8.data(), utf8.size(), &out);
24 return out;
27 #if defined(SYSTEM_NATIVE_UTF8) || defined(OS_ANDROID)
28 // TODO(port): Consider reverting the OS_ANDROID when we have wcrtomb()
29 // support and a better understanding of what calls these routines.
31 std::string SysWideToNativeMB(const std::wstring& wide) {
32 return WideToUTF8(wide);
35 std::wstring SysNativeMBToWide(const StringPiece& native_mb) {
36 return SysUTF8ToWide(native_mb);
39 #else
41 std::string SysWideToNativeMB(const std::wstring& wide) {
42 mbstate_t ps;
44 // Calculate the number of multi-byte characters. We walk through the string
45 // without writing the output, counting the number of multi-byte characters.
46 size_t num_out_chars = 0;
47 memset(&ps, 0, sizeof(ps));
48 for (size_t i = 0; i < wide.size(); ++i) {
49 const wchar_t src = wide[i];
50 // Use a temp buffer since calling wcrtomb with an output of NULL does not
51 // calculate the output length.
52 char buf[16];
53 // Skip NULLs to avoid wcrtomb's special handling of them.
54 size_t res = src ? wcrtomb(buf, src, &ps) : 0;
55 switch (res) {
56 // Handle any errors and return an empty string.
57 case static_cast<size_t>(-1):
58 return std::string();
59 break;
60 case 0:
61 // We hit an embedded null byte, keep going.
62 ++num_out_chars;
63 break;
64 default:
65 num_out_chars += res;
66 break;
70 if (num_out_chars == 0)
71 return std::string();
73 std::string out;
74 out.resize(num_out_chars);
76 // We walk the input string again, with |i| tracking the index of the
77 // wide input, and |j| tracking the multi-byte output.
78 memset(&ps, 0, sizeof(ps));
79 for (size_t i = 0, j = 0; i < wide.size(); ++i) {
80 const wchar_t src = wide[i];
81 // We don't want wcrtomb to do its funkiness for embedded NULLs.
82 size_t res = src ? wcrtomb(&out[j], src, &ps) : 0;
83 switch (res) {
84 // Handle any errors and return an empty string.
85 case static_cast<size_t>(-1):
86 return std::string();
87 break;
88 case 0:
89 // We hit an embedded null byte, keep going.
90 ++j; // Output is already zeroed.
91 break;
92 default:
93 j += res;
94 break;
98 return out;
101 std::wstring SysNativeMBToWide(const StringPiece& native_mb) {
102 mbstate_t ps;
104 // Calculate the number of wide characters. We walk through the string
105 // without writing the output, counting the number of wide characters.
106 size_t num_out_chars = 0;
107 memset(&ps, 0, sizeof(ps));
108 for (size_t i = 0; i < native_mb.size(); ) {
109 const char* src = native_mb.data() + i;
110 size_t res = mbrtowc(NULL, src, native_mb.size() - i, &ps);
111 switch (res) {
112 // Handle any errors and return an empty string.
113 case static_cast<size_t>(-2):
114 case static_cast<size_t>(-1):
115 return std::wstring();
116 break;
117 case 0:
118 // We hit an embedded null byte, keep going.
119 i += 1; // Fall through.
120 default:
121 i += res;
122 ++num_out_chars;
123 break;
127 if (num_out_chars == 0)
128 return std::wstring();
130 std::wstring out;
131 out.resize(num_out_chars);
133 memset(&ps, 0, sizeof(ps)); // Clear the shift state.
134 // We walk the input string again, with |i| tracking the index of the
135 // multi-byte input, and |j| tracking the wide output.
136 for (size_t i = 0, j = 0; i < native_mb.size(); ++j) {
137 const char* src = native_mb.data() + i;
138 wchar_t* dst = &out[j];
139 size_t res = mbrtowc(dst, src, native_mb.size() - i, &ps);
140 switch (res) {
141 // Handle any errors and return an empty string.
142 case static_cast<size_t>(-2):
143 case static_cast<size_t>(-1):
144 return std::wstring();
145 break;
146 case 0:
147 i += 1; // Skip null byte.
148 break;
149 default:
150 i += res;
151 break;
155 return out;
158 #endif // OS_CHROMEOS
160 } // namespace base