root/base/strings/utf_string_conversions.cc

DEFINITIONS

1. ConvertUnicode
2. WideToUTF8
3. WideToUTF8
4. UTF8ToWide
5. UTF8ToWide
6. WideToUTF16
7. WideToUTF16
8. UTF16ToWide
9. UTF16ToWide
10. WideToUTF16
11. WideToUTF16
12. UTF16ToWide
13. UTF16ToWide
14. UTF8ToUTF16
15. UTF8ToUTF16
16. UTF16ToUTF8
17. UTF16ToUTF8
18. UTF8ToUTF16
19. UTF8ToUTF16
20. UTF16ToUTF8
21. UTF16ToUTF8
22. ASCIIToWide
23. ASCIIToUTF16
24. UTF16ToASCII

// Copyright (c) 2010 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/strings/utf_string_conversions.h"

#include "base/strings/string_piece.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversion_utils.h"

namespace base {

namespace {

// Generalized Unicode converter -----------------------------------------------

// Converts the given source Unicode character type to the given destination
// Unicode character type as a STL string. The given input buffer and size
// determine the source, and the given output STL string will be replaced by
// the result.
template<typename SRC_CHAR, typename DEST_STRING>
bool ConvertUnicode(const SRC_CHAR* src,
                    size_t src_len,
                    DEST_STRING* output) {
  // ICU requires 32-bit numbers.
  bool success = true;
  int32 src_len32 = static_cast<int32>(src_len);
  for (int32 i = 0; i < src_len32; i++) {
    uint32 code_point;
    if (ReadUnicodeCharacter(src, src_len32, &i, &code_point)) {
      WriteUnicodeCharacter(code_point, output);
    } else {
      WriteUnicodeCharacter(0xFFFD, output);
      success = false;
    }
  }

  return success;
}

}  // namespace

// UTF-8 <-> Wide --------------------------------------------------------------

bool WideToUTF8(const wchar_t* src, size_t src_len, std::string* output) {
  PrepareForUTF8Output(src, src_len, output);
  return ConvertUnicode(src, src_len, output);
}

std::string WideToUTF8(const std::wstring& wide) {
  std::string ret;
  // Ignore the success flag of this call, it will do the best it can for
  // invalid input, which is what we want here.
  WideToUTF8(wide.data(), wide.length(), &ret);
  return ret;
}

bool UTF8ToWide(const char* src, size_t src_len, std::wstring* output) {
  PrepareForUTF16Or32Output(src, src_len, output);
  return ConvertUnicode(src, src_len, output);
}

std::wstring UTF8ToWide(const StringPiece& utf8) {
  std::wstring ret;
  UTF8ToWide(utf8.data(), utf8.length(), &ret);
  return ret;
}

// UTF-16 <-> Wide -------------------------------------------------------------

#if defined(WCHAR_T_IS_UTF16)

// When wide == UTF-16, then conversions are a NOP.
bool WideToUTF16(const wchar_t* src, size_t src_len, string16* output) {
  output->assign(src, src_len);
  return true;
}

string16 WideToUTF16(const std::wstring& wide) {
  return wide;
}

bool UTF16ToWide(const char16* src, size_t src_len, std::wstring* output) {
  output->assign(src, src_len);
  return true;
}

std::wstring UTF16ToWide(const string16& utf16) {
  return utf16;
}

#elif defined(WCHAR_T_IS_UTF32)

bool WideToUTF16(const wchar_t* src, size_t src_len, string16* output) {
  output->clear();
  // Assume that normally we won't have any non-BMP characters so the counts
  // will be the same.
  output->reserve(src_len);
  return ConvertUnicode(src, src_len, output);
}

string16 WideToUTF16(const std::wstring& wide) {
  string16 ret;
  WideToUTF16(wide.data(), wide.length(), &ret);
  return ret;
}

bool UTF16ToWide(const char16* src, size_t src_len, std::wstring* output) {
  output->clear();
  // Assume that normally we won't have any non-BMP characters so the counts
  // will be the same.
  output->reserve(src_len);
  return ConvertUnicode(src, src_len, output);
}

std::wstring UTF16ToWide(const string16& utf16) {
  std::wstring ret;
  UTF16ToWide(utf16.data(), utf16.length(), &ret);
  return ret;
}

#endif  // defined(WCHAR_T_IS_UTF32)

// UTF16 <-> UTF8 --------------------------------------------------------------

#if defined(WCHAR_T_IS_UTF32)

bool UTF8ToUTF16(const char* src, size_t src_len, string16* output) {
  PrepareForUTF16Or32Output(src, src_len, output);
  return ConvertUnicode(src, src_len, output);
}

string16 UTF8ToUTF16(const StringPiece& utf8) {
  string16 ret;
  // Ignore the success flag of this call, it will do the best it can for
  // invalid input, which is what we want here.
  UTF8ToUTF16(utf8.data(), utf8.length(), &ret);
  return ret;
}

bool UTF16ToUTF8(const char16* src, size_t src_len, std::string* output) {
  PrepareForUTF8Output(src, src_len, output);
  return ConvertUnicode(src, src_len, output);
}

std::string UTF16ToUTF8(const string16& utf16) {
  std::string ret;
  // Ignore the success flag of this call, it will do the best it can for
  // invalid input, which is what we want here.
  UTF16ToUTF8(utf16.data(), utf16.length(), &ret);
  return ret;
}

#elif defined(WCHAR_T_IS_UTF16)
// Easy case since we can use the "wide" versions we already wrote above.

bool UTF8ToUTF16(const char* src, size_t src_len, string16* output) {
  return UTF8ToWide(src, src_len, output);
}

string16 UTF8ToUTF16(const StringPiece& utf8) {
  return UTF8ToWide(utf8);
}

bool UTF16ToUTF8(const char16* src, size_t src_len, std::string* output) {
  return WideToUTF8(src, src_len, output);
}

std::string UTF16ToUTF8(const string16& utf16) {
  return WideToUTF8(utf16);
}

#endif

std::wstring ASCIIToWide(const StringPiece& ascii) {
  DCHECK(IsStringASCII(ascii)) << ascii;
  return std::wstring(ascii.begin(), ascii.end());
}

string16 ASCIIToUTF16(const StringPiece& ascii) {
  DCHECK(IsStringASCII(ascii)) << ascii;
  return string16(ascii.begin(), ascii.end());
}

std::string UTF16ToASCII(const string16& utf16) {
  DCHECK(IsStringASCII(utf16)) << UTF16ToUTF8(utf16);
  return std::string(utf16.begin(), utf16.end());
}

}  // namespace base