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// Copyright (c) 2006-2008 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/string_util.h"
#include <string.h>
#include <vector>
#include "base/basictypes.h"
#include "base/logging.h"
#include "base/singleton.h"
#include "unicode/ucnv.h"
#include "unicode/numfmt.h"
#include "unicode/ustring.h"
namespace {
// ReadUnicodeCharacter --------------------------------------------------------
// Reads a UTF-8 stream, placing the next code point into the given output
// |*code_point|. |src| represents the entire string to read, and |*char_index|
// is the character offset within the string to start reading at. |*char_index|
// will be updated to index the last character read, such that incrementing it
// (as in a for loop) will take the reader to the next character.
//
// Returns true on success. On false, |*code_point| will be invalid.
bool ReadUnicodeCharacter(const char* src, int32 src_len,
int32* char_index, uint32* code_point_out) {
// U8_NEXT expects to be able to use -1 to signal an error, so we must
// use a signed type for code_point. But this function returns false
// on error anyway, so code_point_out is unsigned.
int32 code_point;
U8_NEXT(src, *char_index, src_len, code_point);
*code_point_out = static_cast<uint32>(code_point);
// The ICU macro above moves to the next char, we want to point to the last
// char consumed.
(*char_index)--;
// Validate the decoded value.
return U_IS_UNICODE_CHAR(code_point);
}
// Reads a UTF-16 character. The usage is the same as the 8-bit version above.
bool ReadUnicodeCharacter(const char16* src, int32 src_len,
int32* char_index, uint32* code_point) {
if (U16_IS_SURROGATE(src[*char_index])) {
if (!U16_IS_SURROGATE_LEAD(src[*char_index]) ||
*char_index + 1 >= src_len ||
!U16_IS_TRAIL(src[*char_index + 1])) {
// Invalid surrogate pair.
return false;
}
// Valid surrogate pair.
*code_point = U16_GET_SUPPLEMENTARY(src[*char_index],
src[*char_index + 1]);
(*char_index)++;
} else {
// Not a surrogate, just one 16-bit word.
*code_point = src[*char_index];
}
return U_IS_UNICODE_CHAR(*code_point);
}
#if defined(WCHAR_T_IS_UTF32)
// Reads UTF-32 character. The usage is the same as the 8-bit version above.
bool ReadUnicodeCharacter(const wchar_t* src, int32 src_len,
int32* char_index, uint32* code_point) {
// Conversion is easy since the source is 32-bit.
*code_point = src[*char_index];
// Validate the value.
return U_IS_UNICODE_CHAR(*code_point);
}
#endif // defined(WCHAR_T_IS_UTF32)
// WriteUnicodeCharacter -------------------------------------------------------
// Appends a UTF-8 character to the given 8-bit string.
void WriteUnicodeCharacter(uint32 code_point, std::string* output) {
if (code_point <= 0x7f) {
// Fast path the common case of one byte.
output->push_back(code_point);
return;
}
// U8_APPEND_UNSAFE can append up to 4 bytes.
int32 char_offset = static_cast<int32>(output->length());
output->resize(char_offset + U8_MAX_LENGTH);
U8_APPEND_UNSAFE(&(*output)[0], char_offset, code_point);
// U8_APPEND_UNSAFE will advance our pointer past the inserted character, so
// it will represent the new length of the string.
output->resize(char_offset);
}
// Appends the given code point as a UTF-16 character to the STL string.
void WriteUnicodeCharacter(uint32 code_point, string16* output) {
if (U16_LENGTH(code_point) == 1) {
// Thie code point is in the Basic Multilingual Plane (BMP).
output->push_back(static_cast<char16>(code_point));
} else {
// Non-BMP characters use a double-character encoding.
int32 char_offset = static_cast<int32>(output->length());
output->resize(char_offset + U16_MAX_LENGTH);
U16_APPEND_UNSAFE(&(*output)[0], char_offset, code_point);
}
}
#if defined(WCHAR_T_IS_UTF32)
// Appends the given UTF-32 character to the given 32-bit string.
inline void WriteUnicodeCharacter(uint32 code_point, std::wstring* output) {
// This is the easy case, just append the character.
output->push_back(code_point);
}
#endif // defined(WCHAR_T_IS_UTF32)
// 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) {
output->clear();
// 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
success = false;
}
return success;
}
// Guesses the length of the output in UTF-8 in bytes, and reserves that amount
// of space in the given string. We also assume that the input character types
// are unsigned, which will be true for UTF-16 and -32 on our systems. We assume
// the string length is greater than zero.
template<typename CHAR>
void ReserveUTF8Output(const CHAR* src, size_t src_len, std::string* output) {
if (src[0] < 0x80) {
// Assume that the entire input will be ASCII.
output->reserve(src_len);
} else {
// Assume that the entire input is non-ASCII and will have 3 bytes per char.
output->reserve(src_len * 3);
}
}
// Guesses the size of the output buffer (containing either UTF-16 or -32 data)
// given some UTF-8 input that will be converted to it. See ReserveUTF8Output.
// We assume the source length is > 0.
template<typename STRING>
void ReserveUTF16Or32Output(const char* src, size_t src_len, STRING* output) {
if (static_cast<unsigned char>(src[0]) < 0x80) {
// Assume the input is all ASCII, which means 1:1 correspondence.
output->reserve(src_len);
} else {
// Otherwise assume that the UTF-8 sequences will have 2 bytes for each
// character.
output->reserve(src_len / 2);
}
}
} // namespace
// UTF-8 <-> Wide --------------------------------------------------------------
std::string WideToUTF8(const std::wstring& wide) {
std::string ret;
if (wide.empty())
return 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 WideToUTF8(const wchar_t* src, size_t src_len, std::string* output) {
if (src_len == 0) {
output->clear();
return true;
}
ReserveUTF8Output(src, src_len, output);
return ConvertUnicode<wchar_t, std::string>(src, src_len, output);
}
std::wstring UTF8ToWide(const std::string& utf8) {
std::wstring ret;
if (utf8.empty())
return ret;
UTF8ToWide(utf8.data(), utf8.length(), &ret);
return ret;
}
bool UTF8ToWide(const char* src, size_t src_len, std::wstring* output) {
if (src_len == 0) {
output->clear();
return true;
}
ReserveUTF16Or32Output(src, src_len, output);
return ConvertUnicode<char, std::wstring>(src, src_len, output);
}
// UTF-16 <-> Wide -------------------------------------------------------------
#if defined(WCHAR_T_IS_UTF16)
// When wide == UTF-16, then conversions are a NOP.
string16 WideToUTF16(const std::wstring& wide) {
return wide;
}
bool WideToUTF16(const wchar_t* src, size_t src_len, string16* output) {
output->assign(src, src_len);
return true;
}
std::wstring UTF16ToWide(const string16& utf16) {
return utf16;
}
bool UTF16ToWide(const char16* src, size_t src_len, std::wstring* output) {
output->assign(src, src_len);
return true;
}
#elif defined(WCHAR_T_IS_UTF32)
string16 WideToUTF16(const std::wstring& wide) {
string16 ret;
if (wide.empty())
return ret;
WideToUTF16(wide.data(), wide.length(), &ret);
return ret;
}
bool WideToUTF16(const wchar_t* src, size_t src_len, string16* output) {
if (src_len == 0) {
output->clear();
return true;
}
// Assume that normally we won't have any non-BMP characters so the counts
// will be the same.
output->reserve(src_len);
return ConvertUnicode<wchar_t, string16>(src, src_len, output);
}
std::wstring UTF16ToWide(const string16& utf16) {
std::wstring ret;
if (utf16.empty())
return ret;
UTF16ToWide(utf16.data(), utf16.length(), &ret);
return ret;
}
bool UTF16ToWide(const char16* src, size_t src_len, std::wstring* output) {
if (src_len == 0) {
output->clear();
return true;
}
// Assume that normally we won't have any non-BMP characters so the counts
// will be the same.
output->reserve(src_len);
return ConvertUnicode<char16, std::wstring>(src, src_len, output);
}
#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) {
if (src_len == 0) {
output->clear();
return true;
}
ReserveUTF16Or32Output(src, src_len, output);
return ConvertUnicode<char, string16>(src, src_len, output);
}
string16 UTF8ToUTF16(const std::string& utf8) {
string16 ret;
if (utf8.empty())
return 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) {
if (src_len == 0) {
output->clear();
return true;
}
ReserveUTF8Output(src, src_len, output);
return ConvertUnicode<char16, std::string>(src, src_len, output);
}
std::string UTF16ToUTF8(const string16& utf16) {
std::string ret;
if (utf16.empty())
return 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 std::string& 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
// Codepage <-> Wide -----------------------------------------------------------
// Convert a unicode string into the specified codepage_name. If the codepage
// isn't found, return false.
bool WideToCodepage(const std::wstring& wide,
const char* codepage_name,
OnStringUtilConversionError::Type on_error,
std::string* encoded) {
encoded->clear();
UErrorCode status = U_ZERO_ERROR;
UConverter* converter = ucnv_open(codepage_name, &status);
if (!U_SUCCESS(status))
return false;
const UChar* uchar_src;
int uchar_len;
#if defined(WCHAR_T_IS_UTF16)
uchar_src = wide.c_str();
uchar_len = static_cast<int>(wide.length());
#elif defined(WCHAR_T_IS_UTF32)
// When wchar_t is wider than UChar (16 bits), transform |wide| into a
// UChar* string. Size the UChar* buffer to be large enough to hold twice
// as many UTF-16 code points as there are UTF-16 characters, in case each
// character translates to a UTF-16 surrogate pair, and leave room for a NUL
// terminator.
std::vector<UChar> wide_uchar(wide.length() * 2 + 1);
u_strFromWCS(&wide_uchar[0], wide_uchar.size(), &uchar_len,
wide.c_str(), wide.length(), &status);
uchar_src = &wide_uchar[0];
DCHECK(U_SUCCESS(status)) << "failed to convert wstring to UChar*";
#endif // defined(WCHAR_T_IS_UTF32)
int encoded_max_length = UCNV_GET_MAX_BYTES_FOR_STRING(uchar_len,
ucnv_getMaxCharSize(converter));
encoded->resize(encoded_max_length);
// Setup our error handler.
switch (on_error) {
case OnStringUtilConversionError::FAIL:
ucnv_setFromUCallBack(converter, UCNV_FROM_U_CALLBACK_STOP, 0,
NULL, NULL, &status);
break;
case OnStringUtilConversionError::SKIP:
ucnv_setFromUCallBack(converter, UCNV_FROM_U_CALLBACK_SKIP, 0,
NULL, NULL, &status);
break;
default:
NOTREACHED();
}
// ucnv_fromUChars returns size not including terminating null
int actual_size = ucnv_fromUChars(converter, &(*encoded)[0],
encoded_max_length, uchar_src, uchar_len, &status);
encoded->resize(actual_size);
ucnv_close(converter);
if (U_SUCCESS(status))
return true;
encoded->clear(); // Make sure the output is empty on error.
return false;
}
// Converts a string of the given codepage into unicode.
// If the codepage isn't found, return false.
bool CodepageToWide(const std::string& encoded,
const char* codepage_name,
OnStringUtilConversionError::Type on_error,
std::wstring* wide) {
wide->clear();
UErrorCode status = U_ZERO_ERROR;
UConverter* converter = ucnv_open(codepage_name, &status);
if (!U_SUCCESS(status))
return false;
// The worst case is all the input characters are non-BMP (32-bit) ones.
size_t uchar_max_length = encoded.length() * 2 + 1;
UChar* uchar_dst;
#if defined(WCHAR_T_IS_UTF16)
uchar_dst = WriteInto(wide, uchar_max_length);
#elif defined(WCHAR_T_IS_UTF32)
// When wchar_t is wider than UChar (16 bits), convert into a temporary
// UChar* buffer.
std::vector<UChar> wide_uchar(uchar_max_length);
uchar_dst = &wide_uchar[0];
#endif // defined(WCHAR_T_IS_UTF32)
// Setup our error handler.
switch (on_error) {
case OnStringUtilConversionError::FAIL:
ucnv_setToUCallBack(converter, UCNV_TO_U_CALLBACK_STOP, 0,
NULL, NULL, &status);
break;
case OnStringUtilConversionError::SKIP:
ucnv_setToUCallBack(converter, UCNV_TO_U_CALLBACK_SKIP, 0,
NULL, NULL, &status);
break;
default:
NOTREACHED();
}
int actual_size = ucnv_toUChars(converter,
uchar_dst,
static_cast<int>(uchar_max_length),
encoded.data(),
static_cast<int>(encoded.length()),
&status);
ucnv_close(converter);
if (!U_SUCCESS(status)) {
wide->clear(); // Make sure the output is empty on error.
return false;
}
#ifdef WCHAR_T_IS_UTF32
// When wchar_t is wider than UChar (16 bits), it's not possible to wind up
// with any more wchar_t elements than UChar elements. ucnv_toUChars
// returns the number of UChar elements not including the NUL terminator, so
// leave extra room for that.
u_strToWCS(WriteInto(wide, actual_size + 1), actual_size + 1, &actual_size,
uchar_dst, actual_size, &status);
DCHECK(U_SUCCESS(status)) << "failed to convert UChar* to wstring";
#endif // WCHAR_T_IS_UTF32
wide->resize(actual_size);
return true;
}
// Number formatting -----------------------------------------------------------
namespace {
struct NumberFormatSingletonTraits
: public DefaultSingletonTraits<NumberFormat> {
static NumberFormat* New() {
UErrorCode status = U_ZERO_ERROR;
NumberFormat* formatter = NumberFormat::createInstance(status);
DCHECK(U_SUCCESS(status));
return formatter;
}
// There's no ICU call to destroy a NumberFormat object other than
// operator delete, so use the default Delete, which calls operator delete.
// This can cause problems if a different allocator is used by this file than
// by ICU.
};
} // namespace
std::wstring FormatNumber(int64 number) {
NumberFormat* number_format =
Singleton<NumberFormat, NumberFormatSingletonTraits>::get();
if (!number_format) {
// As a fallback, just return the raw number in a string.
return StringPrintf(L"%lld", number);
}
UnicodeString ustr;
number_format->format(number, ustr);
#if defined(WCHAR_T_IS_UTF16)
return std::wstring(ustr.getBuffer(),
static_cast<std::wstring::size_type>(ustr.length()));
#elif defined(WCHAR_T_IS_UTF32)
wchar_t buffer[64]; // A int64 is less than 20 chars long, so 64 chars
// leaves plenty of room for formating stuff.
int length = 0;
UErrorCode error = U_ZERO_ERROR;
u_strToWCS(buffer, 64, &length, ustr.getBuffer(), ustr.length() , &error);
if (U_FAILURE(error)) {
NOTREACHED();
// As a fallback, just return the raw number in a string.
return StringPrintf(L"%lld", number);
}
return std::wstring(buffer, static_cast<std::wstring::size_type>(length));
#endif // defined(WCHAR_T_IS_UTF32)
}
TrimPositions TrimWhitespaceUTF8(const std::string& input,
TrimPositions positions,
std::string* output) {
// This implementation is not so fast since it converts the text encoding
// twice. Please feel free to file a bug if this function hurts the
// performance of Chrome.
DCHECK(IsStringUTF8(input));
std::wstring input_wide = UTF8ToWide(input);
std::wstring output_wide;
TrimPositions result = TrimWhitespace(input_wide, positions, &output_wide);
*output = WideToUTF8(output_wide);
return result;
}
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