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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
// 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 <ctype.h>
#include <errno.h>
#include <math.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <wchar.h>
#include <wctype.h>
#include <algorithm>
#include <vector>
#include "base/basictypes.h"
#include "base/logging.h"
namespace {
// Hack to convert any char-like type to its unsigned counterpart.
// For example, it will convert char, signed char and unsigned char to unsigned
// char.
template <typename T>
struct ToUnsigned {
typedef T Unsigned;
};
template <>
struct ToUnsigned<char> {
typedef unsigned char Unsigned;
};
template <>
struct ToUnsigned<signed char> {
typedef unsigned char Unsigned;
};
template <>
struct ToUnsigned<wchar_t> {
#if defined(XP_WIN)
typedef unsigned short Unsigned;
#else
typedef uint32_t Unsigned;
#endif
};
template <>
struct ToUnsigned<short> {
typedef unsigned short Unsigned;
};
// Generalized string-to-number conversion.
//
// StringToNumberTraits should provide:
// - a typedef for string_type, the STL string type used as input.
// - a typedef for value_type, the target numeric type.
// - a static function, convert_func, which dispatches to an appropriate
// strtol-like function and returns type value_type.
// - a static function, valid_func, which validates |input| and returns a bool
// indicating whether it is in proper form. This is used to check for
// conditions that convert_func tolerates but should result in
// StringToNumber returning false. For strtol-like funtions, valid_func
// should check for leading whitespace.
template <typename StringToNumberTraits>
bool StringToNumber(const typename StringToNumberTraits::string_type& input,
typename StringToNumberTraits::value_type* output) {
typedef StringToNumberTraits traits;
errno = 0; // Thread-safe? It is on at least Mac, Linux, and Windows.
typename traits::string_type::value_type* endptr = NULL;
typename traits::value_type value =
traits::convert_func(input.c_str(), &endptr);
*output = value;
// Cases to return false:
// - If errno is ERANGE, there was an overflow or underflow.
// - If the input string is empty, there was nothing to parse.
// - If endptr does not point to the end of the string, there are either
// characters remaining in the string after a parsed number, or the string
// does not begin with a parseable number. endptr is compared to the
// expected end given the string's stated length to correctly catch cases
// where the string contains embedded NUL characters.
// - valid_func determines that the input is not in preferred form.
return errno == 0 && !input.empty() &&
input.c_str() + input.length() == endptr && traits::valid_func(input);
}
class StringToLongTraits {
public:
typedef std::string string_type;
typedef long value_type;
static const int kBase = 10;
static inline value_type convert_func(const string_type::value_type* str,
string_type::value_type** endptr) {
return strtol(str, endptr, kBase);
}
static inline bool valid_func(const string_type& str) {
return !str.empty() && !isspace(str[0]);
}
};
class String16ToLongTraits {
public:
typedef string16 string_type;
typedef long value_type;
static const int kBase = 10;
static inline value_type convert_func(const string_type::value_type* str,
string_type::value_type** endptr) {
#if defined(XP_WIN)
return wcstol(str, endptr, kBase);
#else
std::string ascii_string = UTF16ToASCII(string16(str));
char* ascii_end = NULL;
value_type ret = strtol(ascii_string.c_str(), &ascii_end, kBase);
if (ascii_string.c_str() + ascii_string.length() == ascii_end) {
*endptr =
const_cast<string_type::value_type*>(str) + ascii_string.length();
}
return ret;
#endif
}
static inline bool valid_func(const string_type& str) {
return !str.empty() && !iswspace(str[0]);
}
};
class StringToInt64Traits {
public:
typedef std::string string_type;
typedef int64_t value_type;
static const int kBase = 10;
static inline value_type convert_func(const string_type::value_type* str,
string_type::value_type** endptr) {
#ifdef XP_WIN
return _strtoi64(str, endptr, kBase);
#else // assume XP_UNIX
return strtoll(str, endptr, kBase);
#endif
}
static inline bool valid_func(const string_type& str) {
return !str.empty() && !isspace(str[0]);
}
};
class String16ToInt64Traits {
public:
typedef string16 string_type;
typedef int64_t value_type;
static const int kBase = 10;
static inline value_type convert_func(const string_type::value_type* str,
string_type::value_type** endptr) {
#ifdef XP_WIN
return _wcstoi64(str, endptr, kBase);
#else // assume XP_UNIX
std::string ascii_string = UTF16ToASCII(string16(str));
char* ascii_end = NULL;
value_type ret = strtoll(ascii_string.c_str(), &ascii_end, kBase);
if (ascii_string.c_str() + ascii_string.length() == ascii_end) {
*endptr =
const_cast<string_type::value_type*>(str) + ascii_string.length();
}
return ret;
#endif
}
static inline bool valid_func(const string_type& str) {
return !str.empty() && !iswspace(str[0]);
}
};
} // namespace
namespace base {
bool IsWprintfFormatPortable(const wchar_t* format) {
for (const wchar_t* position = format; *position != '\0'; ++position) {
if (*position == '%') {
bool in_specification = true;
bool modifier_l = false;
while (in_specification) {
// Eat up characters until reaching a known specifier.
if (*++position == '\0') {
// The format string ended in the middle of a specification. Call
// it portable because no unportable specifications were found. The
// string is equally broken on all platforms.
return true;
}
if (*position == 'l') {
// 'l' is the only thing that can save the 's' and 'c' specifiers.
modifier_l = true;
} else if (((*position == 's' || *position == 'c') && !modifier_l) ||
*position == 'S' || *position == 'C' || *position == 'F' ||
*position == 'D' || *position == 'O' || *position == 'U') {
// Not portable.
return false;
}
if (wcschr(L"diouxXeEfgGaAcspn%", *position)) {
// Portable, keep scanning the rest of the format string.
in_specification = false;
}
}
}
}
return true;
}
} // namespace base
static const wchar_t kWhitespaceWide[] = {
0x0009, // <control-0009> to <control-000D>
0x000A, 0x000B, 0x000C, 0x000D,
0x0020, // Space
0x0085, // <control-0085>
0x00A0, // No-Break Space
0x1680, // Ogham Space Mark
0x180E, // Mongolian Vowel Separator
0x2000, // En Quad to Hair Space
0x2001, 0x2002, 0x2003, 0x2004, 0x2005,
0x2006, 0x2007, 0x2008, 0x2009, 0x200A,
0x200C, // Zero Width Non-Joiner
0x2028, // Line Separator
0x2029, // Paragraph Separator
0x202F, // Narrow No-Break Space
0x205F, // Medium Mathematical Space
0x3000, // Ideographic Space
0};
static const char kWhitespaceASCII[] = {
0x09, // <control-0009> to <control-000D>
0x0A, 0x0B, 0x0C, 0x0D,
0x20, // Space
0};
template <typename STR>
TrimPositions TrimStringT(const STR& input,
const typename STR::value_type trim_chars[],
TrimPositions positions, STR* output) {
// Find the edges of leading/trailing whitespace as desired.
const typename STR::size_type last_char = input.length() - 1;
const typename STR::size_type first_good_char =
(positions & TRIM_LEADING) ? input.find_first_not_of(trim_chars) : 0;
const typename STR::size_type last_good_char =
(positions & TRIM_TRAILING) ? input.find_last_not_of(trim_chars)
: last_char;
// When the string was all whitespace, report that we stripped off whitespace
// from whichever position the caller was interested in. For empty input, we
// stripped no whitespace, but we still need to clear |output|.
if (input.empty() || (first_good_char == STR::npos) ||
(last_good_char == STR::npos)) {
bool input_was_empty = input.empty(); // in case output == &input
output->clear();
return input_was_empty ? TRIM_NONE : positions;
}
// Trim the whitespace.
*output = input.substr(first_good_char, last_good_char - first_good_char + 1);
// Return where we trimmed from.
return static_cast<TrimPositions>(
((first_good_char == 0) ? TRIM_NONE : TRIM_LEADING) |
((last_good_char == last_char) ? TRIM_NONE : TRIM_TRAILING));
}
TrimPositions TrimWhitespace(const std::wstring& input, TrimPositions positions,
std::wstring* output) {
return TrimStringT(input, kWhitespaceWide, positions, output);
}
TrimPositions TrimWhitespaceASCII(const std::string& input,
TrimPositions positions,
std::string* output) {
return TrimStringT(input, kWhitespaceASCII, positions, output);
}
// This function is only for backward-compatibility.
// To be removed when all callers are updated.
TrimPositions TrimWhitespace(const std::string& input, TrimPositions positions,
std::string* output) {
return TrimWhitespaceASCII(input, positions, output);
}
std::string WideToASCII(const std::wstring& wide) {
DCHECK(IsStringASCII(wide));
return std::string(wide.begin(), wide.end());
}
std::wstring ASCIIToWide(const std::string& ascii) {
DCHECK(IsStringASCII(ascii));
return std::wstring(ascii.begin(), ascii.end());
}
std::string UTF16ToASCII(const string16& utf16) {
DCHECK(IsStringASCII(utf16));
return std::string(utf16.begin(), utf16.end());
}
string16 ASCIIToUTF16(const std::string& ascii) {
DCHECK(IsStringASCII(ascii));
return string16(ascii.begin(), ascii.end());
}
template <class STR>
static bool DoIsStringASCII(const STR& str) {
for (size_t i = 0; i < str.length(); i++) {
typename ToUnsigned<typename STR::value_type>::Unsigned c = str[i];
if (c > 0x7F) return false;
}
return true;
}
bool IsStringASCII(const std::wstring& str) { return DoIsStringASCII(str); }
#if !defined(XP_WIN)
bool IsStringASCII(const string16& str) { return DoIsStringASCII(str); }
#endif
bool IsStringASCII(const std::string& str) { return DoIsStringASCII(str); }
// Overloaded wrappers around vsnprintf and vswprintf. The buf_size parameter
// is the size of the buffer. These return the number of characters in the
// formatted string excluding the NUL terminator. If the buffer is not
// large enough to accommodate the formatted string without truncation, they
// return the number of characters that would be in the fully-formatted string
// (vsnprintf, and vswprintf on Windows), or -1 (vswprintf on POSIX platforms).
inline int vsnprintfT(char* buffer, size_t buf_size, const char* format,
va_list argptr) {
return base::vsnprintf(buffer, buf_size, format, argptr);
}
inline int vsnprintfT(wchar_t* buffer, size_t buf_size, const wchar_t* format,
va_list argptr) {
return base::vswprintf(buffer, buf_size, format, argptr);
}
// Templatized backend for StringPrintF/StringAppendF. This does not finalize
// the va_list, the caller is expected to do that.
template <class StringType>
static void StringAppendVT(StringType* dst,
const typename StringType::value_type* format,
va_list ap) {
// First try with a small fixed size buffer.
// This buffer size should be kept in sync with StringUtilTest.GrowBoundary
// and StringUtilTest.StringPrintfBounds.
typename StringType::value_type stack_buf[1024];
va_list backup_ap;
base_va_copy(backup_ap, ap);
#if !defined(XP_WIN)
errno = 0;
#endif
int result = vsnprintfT(stack_buf, arraysize(stack_buf), format, backup_ap);
va_end(backup_ap);
if (result >= 0 && result < static_cast<int>(arraysize(stack_buf))) {
// It fit.
dst->append(stack_buf, result);
return;
}
// Repeatedly increase buffer size until it fits.
int mem_length = arraysize(stack_buf);
while (true) {
if (result < 0) {
#if !defined(XP_WIN)
// On Windows, vsnprintfT always returns the number of characters in a
// fully-formatted string, so if we reach this point, something else is
// wrong and no amount of buffer-doubling is going to fix it.
if (errno != 0 && errno != EOVERFLOW)
#endif
{
// If an error other than overflow occurred, it's never going to work.
DLOG(WARNING) << "Unable to printf the requested string due to error.";
return;
}
// Try doubling the buffer size.
mem_length *= 2;
} else {
// We need exactly "result + 1" characters.
mem_length = result + 1;
}
if (mem_length > 32 * 1024 * 1024) {
// That should be plenty, don't try anything larger. This protects
// against huge allocations when using vsnprintfT implementations that
// return -1 for reasons other than overflow without setting errno.
DLOG(WARNING) << "Unable to printf the requested string due to size.";
return;
}
std::vector<typename StringType::value_type> mem_buf(mem_length);
// Restore the va_list before we use it again.
base_va_copy(backup_ap, ap);
result = vsnprintfT(&mem_buf[0], mem_length, format, ap);
va_end(backup_ap);
if ((result >= 0) && (result < mem_length)) {
// It fit.
dst->append(&mem_buf[0], result);
return;
}
}
}
namespace {
template <typename STR, typename INT, typename UINT, bool NEG>
struct IntToStringT {
// This is to avoid a compiler warning about unary minus on unsigned type.
// For example, say you had the following code:
// template <typename INT>
// INT abs(INT value) { return value < 0 ? -value : value; }
// Even though if INT is unsigned, it's impossible for value < 0, so the
// unary minus will never be taken, the compiler will still generate a
// warning. We do a little specialization dance...
template <typename INT2, typename UINT2, bool NEG2>
struct ToUnsignedT {};
template <typename INT2, typename UINT2>
struct ToUnsignedT<INT2, UINT2, false> {
static UINT2 ToUnsigned(INT2 value) { return static_cast<UINT2>(value); }
};
template <typename INT2, typename UINT2>
struct ToUnsignedT<INT2, UINT2, true> {
static UINT2 ToUnsigned(INT2 value) {
return static_cast<UINT2>(value < 0 ? -value : value);
}
};
// This set of templates is very similar to the above templates, but
// for testing whether an integer is negative.
template <typename INT2, bool NEG2>
struct TestNegT {};
template <typename INT2>
struct TestNegT<INT2, false> {
static bool TestNeg(INT2 value) {
// value is unsigned, and can never be negative.
return false;
}
};
template <typename INT2>
struct TestNegT<INT2, true> {
static bool TestNeg(INT2 value) { return value < 0; }
};
static STR IntToString(INT value) {
// log10(2) ~= 0.3 bytes needed per bit or per byte log10(2**8) ~= 2.4.
// So round up to allocate 3 output characters per byte, plus 1 for '-'.
const int kOutputBufSize = 3 * sizeof(INT) + 1;
// Allocate the whole string right away, we will right back to front, and
// then return the substr of what we ended up using.
STR outbuf(kOutputBufSize, 0);
bool is_neg = TestNegT<INT, NEG>::TestNeg(value);
// Even though is_neg will never be true when INT is parameterized as
// unsigned, even the presence of the unary operation causes a warning.
UINT res = ToUnsignedT<INT, UINT, NEG>::ToUnsigned(value);
for (typename STR::iterator it = outbuf.end();;) {
--it;
DCHECK(it != outbuf.begin());
*it = static_cast<typename STR::value_type>((res % 10) + '0');
res /= 10;
// We're done..
if (res == 0) {
if (is_neg) {
--it;
DCHECK(it != outbuf.begin());
*it = static_cast<typename STR::value_type>('-');
}
return STR(it, outbuf.end());
}
}
NOTREACHED();
return STR();
}
};
} // namespace
std::string IntToString(int value) {
return IntToStringT<std::string, int, unsigned int, true>::IntToString(value);
}
std::wstring IntToWString(int value) {
return IntToStringT<std::wstring, int, unsigned int, true>::IntToString(
value);
}
std::string UintToString(unsigned int value) {
return IntToStringT<std::string, unsigned int, unsigned int,
false>::IntToString(value);
}
std::wstring UintToWString(unsigned int value) {
return IntToStringT<std::wstring, unsigned int, unsigned int,
false>::IntToString(value);
}
std::string Int64ToString(int64_t value) {
return IntToStringT<std::string, int64_t, uint64_t, true>::IntToString(value);
}
std::wstring Int64ToWString(int64_t value) {
return IntToStringT<std::wstring, int64_t, uint64_t, true>::IntToString(
value);
}
std::string Uint64ToString(uint64_t value) {
return IntToStringT<std::string, uint64_t, uint64_t, false>::IntToString(
value);
}
std::wstring Uint64ToWString(uint64_t value) {
return IntToStringT<std::wstring, uint64_t, uint64_t, false>::IntToString(
value);
}
// Lower-level routine that takes a va_list and appends to a specified
// string. All other routines are just convenience wrappers around it.
static void StringAppendV(std::string* dst, const char* format, va_list ap) {
StringAppendVT(dst, format, ap);
}
static void StringAppendV(std::wstring* dst, const wchar_t* format,
va_list ap) {
StringAppendVT(dst, format, ap);
}
std::string StringPrintf(const char* format, ...) {
va_list ap;
va_start(ap, format);
std::string result;
StringAppendV(&result, format, ap);
va_end(ap);
return result;
}
std::wstring StringPrintf(const wchar_t* format, ...) {
va_list ap;
va_start(ap, format);
std::wstring result;
StringAppendV(&result, format, ap);
va_end(ap);
return result;
}
const std::string& SStringPrintf(std::string* dst, const char* format, ...) {
va_list ap;
va_start(ap, format);
dst->clear();
StringAppendV(dst, format, ap);
va_end(ap);
return *dst;
}
const std::wstring& SStringPrintf(std::wstring* dst, const wchar_t* format,
...) {
va_list ap;
va_start(ap, format);
dst->clear();
StringAppendV(dst, format, ap);
va_end(ap);
return *dst;
}
void StringAppendF(std::string* dst, const char* format, ...) {
va_list ap;
va_start(ap, format);
StringAppendV(dst, format, ap);
va_end(ap);
}
void StringAppendF(std::wstring* dst, const wchar_t* format, ...) {
va_list ap;
va_start(ap, format);
StringAppendV(dst, format, ap);
va_end(ap);
}
template <typename STR>
static void SplitStringT(const STR& str, const typename STR::value_type s,
bool trim_whitespace, std::vector<STR>* r) {
size_t last = 0;
size_t i;
size_t c = str.size();
for (i = 0; i <= c; ++i) {
if (i == c || str[i] == s) {
size_t len = i - last;
STR tmp = str.substr(last, len);
if (trim_whitespace) {
STR t_tmp;
TrimWhitespace(tmp, TRIM_ALL, &t_tmp);
r->push_back(t_tmp);
} else {
r->push_back(tmp);
}
last = i + 1;
}
}
}
void SplitString(const std::wstring& str, wchar_t s,
std::vector<std::wstring>* r) {
SplitStringT(str, s, true, r);
}
void SplitString(const std::string& str, char s, std::vector<std::string>* r) {
SplitStringT(str, s, true, r);
}
// For the various *ToInt conversions, there are no *ToIntTraits classes to use
// because there's no such thing as strtoi. Use *ToLongTraits through a cast
// instead, requiring that long and int are compatible and equal-width. They
// are on our target platforms.
// XXX Sigh.
#if !defined(HAVE_64BIT_BUILD)
bool StringToInt(const std::string& input, int* output) {
COMPILE_ASSERT(sizeof(int) == sizeof(long), cannot_strtol_to_int);
return StringToNumber<StringToLongTraits>(input,
reinterpret_cast<long*>(output));
}
bool StringToInt(const string16& input, int* output) {
COMPILE_ASSERT(sizeof(int) == sizeof(long), cannot_wcstol_to_int);
return StringToNumber<String16ToLongTraits>(input,
reinterpret_cast<long*>(output));
}
#else
bool StringToInt(const std::string& input, int* output) {
long tmp;
bool ok = StringToNumber<StringToLongTraits>(input, &tmp);
if (!ok || tmp > kint32max) {
return false;
}
*output = static_cast<int>(tmp);
return true;
}
bool StringToInt(const string16& input, int* output) {
long tmp;
bool ok = StringToNumber<String16ToLongTraits>(input, &tmp);
if (!ok || tmp > kint32max) {
return false;
}
*output = static_cast<int>(tmp);
return true;
}
#endif // !defined(HAVE_64BIT_BUILD)
bool StringToInt64(const std::string& input, int64_t* output) {
return StringToNumber<StringToInt64Traits>(input, output);
}
bool StringToInt64(const string16& input, int64_t* output) {
return StringToNumber<String16ToInt64Traits>(input, output);
}
int StringToInt(const std::string& value) {
int result;
StringToInt(value, &result);
return result;
}
int StringToInt(const string16& value) {
int result;
StringToInt(value, &result);
return result;
}
int64_t StringToInt64(const std::string& value) {
int64_t result;
StringToInt64(value, &result);
return result;
}
int64_t StringToInt64(const string16& value) {
int64_t result;
StringToInt64(value, &result);
return result;
}
// The following code is compatible with the OpenBSD lcpy interface. See:
namespace {
template <typename CHAR>
size_t lcpyT(CHAR* dst, const CHAR* src, size_t dst_size) {
for (size_t i = 0; i < dst_size; ++i) {
if ((dst[i] = src[i]) == 0) // We hit and copied the terminating NULL.
return i;
}
// We were left off at dst_size. We over copied 1 byte. Null terminate.
if (dst_size != 0) dst[dst_size - 1] = 0;
// Count the rest of the |src|, and return it's length in characters.
while (src[dst_size]) ++dst_size;
return dst_size;
}
} // namespace
size_t base::strlcpy(char* dst, const char* src, size_t dst_size) {
return lcpyT<char>(dst, src, dst_size);
}
size_t base::wcslcpy(wchar_t* dst, const wchar_t* src, size_t dst_size) {
return lcpyT<wchar_t>(dst, src, dst_size);
}