diff options
Diffstat (limited to 'chromium/base/strings/string_number_conversions.cc')
| -rw-r--r-- | chromium/base/strings/string_number_conversions.cc | 461 |
1 files changed, 45 insertions, 416 deletions
diff --git a/chromium/base/strings/string_number_conversions.cc b/chromium/base/strings/string_number_conversions.cc index bd0a7e435f6..e2ef8acf66f 100644 --- a/chromium/base/strings/string_number_conversions.cc +++ b/chromium/base/strings/string_number_conversions.cc @@ -4,458 +4,120 @@ #include "base/strings/string_number_conversions.h" -#include <ctype.h> -#include <errno.h> -#include <stdlib.h> -#include <wctype.h> +#include <iterator> +#include <string> -#include <limits> -#include <type_traits> - -#include "base/check_op.h" -#include "base/no_destructor.h" -#include "base/numerics/safe_math.h" -#include "base/strings/string_util.h" -#include "base/strings/utf_string_conversions.h" -#include "base/third_party/double_conversion/double-conversion/double-conversion.h" +#include "base/containers/span.h" +#include "base/logging.h" +#include "base/strings/string16.h" +#include "base/strings/string_number_conversions_internal.h" +#include "base/strings/string_piece.h" namespace base { -namespace { - -template <typename STR, typename INT> -struct IntToStringT { - 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 size_t kOutputBufSize = - 3 * sizeof(INT) + std::numeric_limits<INT>::is_signed; - - // Create the string in a temporary buffer, write it back to front, and - // then return the substr of what we ended up using. - using CHR = typename STR::value_type; - CHR outbuf[kOutputBufSize]; - - // The ValueOrDie call below can never fail, because UnsignedAbs is valid - // for all valid inputs. - typename std::make_unsigned<INT>::type res = - CheckedNumeric<INT>(value).UnsignedAbs().ValueOrDie(); - - CHR* end = outbuf + kOutputBufSize; - CHR* i = end; - do { - --i; - DCHECK(i != outbuf); - *i = static_cast<CHR>((res % 10) + '0'); - res /= 10; - } while (res != 0); - if (IsValueNegative(value)) { - --i; - DCHECK(i != outbuf); - *i = static_cast<CHR>('-'); - } - return STR(i, end); - } -}; - -// Utility to convert a character to a digit in a given base -template<typename CHAR, int BASE, bool BASE_LTE_10> class BaseCharToDigit { -}; - -// Faster specialization for bases <= 10 -template<typename CHAR, int BASE> class BaseCharToDigit<CHAR, BASE, true> { - public: - static bool Convert(CHAR c, uint8_t* digit) { - if (c >= '0' && c < '0' + BASE) { - *digit = static_cast<uint8_t>(c - '0'); - return true; - } - return false; - } -}; - -// Specialization for bases where 10 < base <= 36 -template<typename CHAR, int BASE> class BaseCharToDigit<CHAR, BASE, false> { - public: - static bool Convert(CHAR c, uint8_t* digit) { - if (c >= '0' && c <= '9') { - *digit = c - '0'; - } else if (c >= 'a' && c < 'a' + BASE - 10) { - *digit = c - 'a' + 10; - } else if (c >= 'A' && c < 'A' + BASE - 10) { - *digit = c - 'A' + 10; - } else { - return false; - } - return true; - } -}; - -template <int BASE, typename CHAR> -bool CharToDigit(CHAR c, uint8_t* digit) { - return BaseCharToDigit<CHAR, BASE, BASE <= 10>::Convert(c, digit); -} - -// There is an IsUnicodeWhitespace for wchars defined in string_util.h, but it -// is locale independent, whereas the functions we are replacing were -// locale-dependent. TBD what is desired, but for the moment let's not -// introduce a change in behaviour. -template<typename CHAR> class WhitespaceHelper { -}; - -template<> class WhitespaceHelper<char> { - public: - static bool Invoke(char c) { - return 0 != isspace(static_cast<unsigned char>(c)); - } -}; - -template<> class WhitespaceHelper<char16> { - public: - static bool Invoke(char16 c) { - return 0 != iswspace(c); - } -}; - -template<typename CHAR> bool LocalIsWhitespace(CHAR c) { - return WhitespaceHelper<CHAR>::Invoke(c); -} - -// IteratorRangeToNumberTraits should provide: -// - a typedef for iterator_type, the iterator type used as input. -// - a typedef for value_type, the target numeric type. -// - static functions min, max (returning the minimum and maximum permitted -// values) -// - constant kBase, the base in which to interpret the input -template<typename IteratorRangeToNumberTraits> -class IteratorRangeToNumber { - public: - typedef IteratorRangeToNumberTraits traits; - typedef typename traits::iterator_type const_iterator; - typedef typename traits::value_type value_type; - - // Generalized iterator-range-to-number conversion. - // - static bool Invoke(const_iterator begin, - const_iterator end, - value_type* output) { - bool valid = true; - - while (begin != end && LocalIsWhitespace(*begin)) { - valid = false; - ++begin; - } - - if (begin != end && *begin == '-') { - if (!std::numeric_limits<value_type>::is_signed) { - *output = 0; - valid = false; - } else if (!Negative::Invoke(begin + 1, end, output)) { - valid = false; - } - } else { - if (begin != end && *begin == '+') { - ++begin; - } - if (!Positive::Invoke(begin, end, output)) { - valid = false; - } - } - - return valid; - } - - private: - // Sign provides: - // - a static function, CheckBounds, that determines whether the next digit - // causes an overflow/underflow - // - a static function, Increment, that appends the next digit appropriately - // according to the sign of the number being parsed. - template<typename Sign> - class Base { - public: - static bool Invoke(const_iterator begin, const_iterator end, - typename traits::value_type* output) { - *output = 0; - - if (begin == end) { - return false; - } - - // Note: no performance difference was found when using template - // specialization to remove this check in bases other than 16 - if (traits::kBase == 16 && end - begin > 2 && *begin == '0' && - (*(begin + 1) == 'x' || *(begin + 1) == 'X')) { - begin += 2; - } - - for (const_iterator current = begin; current != end; ++current) { - uint8_t new_digit = 0; - - if (!CharToDigit<traits::kBase>(*current, &new_digit)) { - return false; - } - - if (current != begin) { - if (!Sign::CheckBounds(output, new_digit)) { - return false; - } - *output *= traits::kBase; - } - - Sign::Increment(new_digit, output); - } - return true; - } - }; - - class Positive : public Base<Positive> { - public: - static bool CheckBounds(value_type* output, uint8_t new_digit) { - if (*output > static_cast<value_type>(traits::max() / traits::kBase) || - (*output == static_cast<value_type>(traits::max() / traits::kBase) && - new_digit > traits::max() % traits::kBase)) { - *output = traits::max(); - return false; - } - return true; - } - static void Increment(uint8_t increment, value_type* output) { - *output += increment; - } - }; - - class Negative : public Base<Negative> { - public: - static bool CheckBounds(value_type* output, uint8_t new_digit) { - if (*output < traits::min() / traits::kBase || - (*output == traits::min() / traits::kBase && - new_digit > 0 - traits::min() % traits::kBase)) { - *output = traits::min(); - return false; - } - return true; - } - static void Increment(uint8_t increment, value_type* output) { - *output -= increment; - } - }; -}; - -template<typename ITERATOR, typename VALUE, int BASE> -class BaseIteratorRangeToNumberTraits { - public: - typedef ITERATOR iterator_type; - typedef VALUE value_type; - static value_type min() { - return std::numeric_limits<value_type>::min(); - } - static value_type max() { - return std::numeric_limits<value_type>::max(); - } - static const int kBase = BASE; -}; - -template<typename ITERATOR> -class BaseHexIteratorRangeToIntTraits - : public BaseIteratorRangeToNumberTraits<ITERATOR, int, 16> { -}; - -template <typename ITERATOR> -class BaseHexIteratorRangeToUIntTraits - : public BaseIteratorRangeToNumberTraits<ITERATOR, uint32_t, 16> {}; - -template <typename ITERATOR> -class BaseHexIteratorRangeToInt64Traits - : public BaseIteratorRangeToNumberTraits<ITERATOR, int64_t, 16> {}; - -template <typename ITERATOR> -class BaseHexIteratorRangeToUInt64Traits - : public BaseIteratorRangeToNumberTraits<ITERATOR, uint64_t, 16> {}; - -typedef BaseHexIteratorRangeToIntTraits<StringPiece::const_iterator> - HexIteratorRangeToIntTraits; - -typedef BaseHexIteratorRangeToUIntTraits<StringPiece::const_iterator> - HexIteratorRangeToUIntTraits; - -typedef BaseHexIteratorRangeToInt64Traits<StringPiece::const_iterator> - HexIteratorRangeToInt64Traits; - -typedef BaseHexIteratorRangeToUInt64Traits<StringPiece::const_iterator> - HexIteratorRangeToUInt64Traits; - -template <typename VALUE, int BASE> -class StringPieceToNumberTraits - : public BaseIteratorRangeToNumberTraits<StringPiece::const_iterator, - VALUE, - BASE> { -}; - -template <typename VALUE> -bool StringToIntImpl(StringPiece input, VALUE* output) { - return IteratorRangeToNumber<StringPieceToNumberTraits<VALUE, 10> >::Invoke( - input.begin(), input.end(), output); -} - -template <typename VALUE, int BASE> -class StringPiece16ToNumberTraits - : public BaseIteratorRangeToNumberTraits<StringPiece16::const_iterator, - VALUE, - BASE> { -}; - -template <typename VALUE> -bool String16ToIntImpl(StringPiece16 input, VALUE* output) { - return IteratorRangeToNumber<StringPiece16ToNumberTraits<VALUE, 10> >::Invoke( - input.begin(), input.end(), output); -} - -} // namespace - std::string NumberToString(int value) { - return IntToStringT<std::string, int>::IntToString(value); + return internal::IntToStringT<std::string>(value); } string16 NumberToString16(int value) { - return IntToStringT<string16, int>::IntToString(value); + return internal::IntToStringT<string16>(value); } std::string NumberToString(unsigned value) { - return IntToStringT<std::string, unsigned>::IntToString(value); + return internal::IntToStringT<std::string>(value); } string16 NumberToString16(unsigned value) { - return IntToStringT<string16, unsigned>::IntToString(value); + return internal::IntToStringT<string16>(value); } std::string NumberToString(long value) { - return IntToStringT<std::string, long>::IntToString(value); + return internal::IntToStringT<std::string>(value); } string16 NumberToString16(long value) { - return IntToStringT<string16, long>::IntToString(value); + return internal::IntToStringT<string16>(value); } std::string NumberToString(unsigned long value) { - return IntToStringT<std::string, unsigned long>::IntToString(value); + return internal::IntToStringT<std::string>(value); } string16 NumberToString16(unsigned long value) { - return IntToStringT<string16, unsigned long>::IntToString(value); + return internal::IntToStringT<string16>(value); } std::string NumberToString(long long value) { - return IntToStringT<std::string, long long>::IntToString(value); + return internal::IntToStringT<std::string>(value); } string16 NumberToString16(long long value) { - return IntToStringT<string16, long long>::IntToString(value); + return internal::IntToStringT<string16>(value); } std::string NumberToString(unsigned long long value) { - return IntToStringT<std::string, unsigned long long>::IntToString(value); + return internal::IntToStringT<std::string>(value); } string16 NumberToString16(unsigned long long value) { - return IntToStringT<string16, unsigned long long>::IntToString(value); -} - -static const double_conversion::DoubleToStringConverter* -GetDoubleToStringConverter() { - static NoDestructor<double_conversion::DoubleToStringConverter> converter( - double_conversion::DoubleToStringConverter::EMIT_POSITIVE_EXPONENT_SIGN, - nullptr, nullptr, 'e', -6, 12, 0, 0); - return converter.get(); + return internal::IntToStringT<string16>(value); } std::string NumberToString(double value) { - char buffer[32]; - double_conversion::StringBuilder builder(buffer, sizeof(buffer)); - GetDoubleToStringConverter()->ToShortest(value, &builder); - return std::string(buffer, builder.position()); + return internal::DoubleToStringT<std::string>(value); } -base::string16 NumberToString16(double value) { - char buffer[32]; - double_conversion::StringBuilder builder(buffer, sizeof(buffer)); - GetDoubleToStringConverter()->ToShortest(value, &builder); - - // The number will be ASCII. This creates the string using the "input - // iterator" variant which promotes from 8-bit to 16-bit via "=". - return base::string16(&buffer[0], &buffer[builder.position()]); +string16 NumberToString16(double value) { + return internal::DoubleToStringT<string16>(value); } bool StringToInt(StringPiece input, int* output) { - return StringToIntImpl(input, output); + return internal::StringToIntImpl(input, *output); } bool StringToInt(StringPiece16 input, int* output) { - return String16ToIntImpl(input, output); + return internal::StringToIntImpl(input, *output); } bool StringToUint(StringPiece input, unsigned* output) { - return StringToIntImpl(input, output); + return internal::StringToIntImpl(input, *output); } bool StringToUint(StringPiece16 input, unsigned* output) { - return String16ToIntImpl(input, output); + return internal::StringToIntImpl(input, *output); } bool StringToInt64(StringPiece input, int64_t* output) { - return StringToIntImpl(input, output); + return internal::StringToIntImpl(input, *output); } bool StringToInt64(StringPiece16 input, int64_t* output) { - return String16ToIntImpl(input, output); + return internal::StringToIntImpl(input, *output); } bool StringToUint64(StringPiece input, uint64_t* output) { - return StringToIntImpl(input, output); + return internal::StringToIntImpl(input, *output); } bool StringToUint64(StringPiece16 input, uint64_t* output) { - return String16ToIntImpl(input, output); + return internal::StringToIntImpl(input, *output); } bool StringToSizeT(StringPiece input, size_t* output) { - return StringToIntImpl(input, output); + return internal::StringToIntImpl(input, *output); } bool StringToSizeT(StringPiece16 input, size_t* output) { - return String16ToIntImpl(input, output); -} - -template <typename STRING, typename CHAR> -bool StringToDoubleImpl(STRING input, const CHAR* data, double* output) { - static NoDestructor<double_conversion::StringToDoubleConverter> converter( - double_conversion::StringToDoubleConverter::ALLOW_LEADING_SPACES | - double_conversion::StringToDoubleConverter::ALLOW_TRAILING_JUNK, - 0.0, 0, nullptr, nullptr); - - int processed_characters_count; - *output = converter->StringToDouble(data, input.size(), - &processed_characters_count); - - // Cases to return false: - // - If the input string is empty, there was nothing to parse. - // - If the value saturated to HUGE_VAL. - // - If the entire string was not processed, there are either characters - // remaining in the string after a parsed number, or the string does not - // begin with a parseable number. - // - If the first character is a space, there was leading whitespace - return !input.empty() && *output != HUGE_VAL && *output != -HUGE_VAL && - static_cast<size_t>(processed_characters_count) == input.size() && - !IsUnicodeWhitespace(input[0]); + return internal::StringToIntImpl(input, *output); } bool StringToDouble(StringPiece input, double* output) { - return StringToDoubleImpl(input, input.data(), output); + return internal::StringToDoubleImpl(input, input.data(), *output); } bool StringToDouble(StringPiece16 input, double* output) { - return StringToDoubleImpl( - input, reinterpret_cast<const uint16_t*>(input.data()), output); + return internal::StringToDoubleImpl( + input, reinterpret_cast<const uint16_t*>(input.data()), *output); } std::string HexEncode(const void* bytes, size_t size) { @@ -477,69 +139,36 @@ std::string HexEncode(base::span<const uint8_t> bytes) { } bool HexStringToInt(StringPiece input, int* output) { - return IteratorRangeToNumber<HexIteratorRangeToIntTraits>::Invoke( - input.begin(), input.end(), output); + return internal::HexStringToIntImpl(input, *output); } bool HexStringToUInt(StringPiece input, uint32_t* output) { - return IteratorRangeToNumber<HexIteratorRangeToUIntTraits>::Invoke( - input.begin(), input.end(), output); + return internal::HexStringToIntImpl(input, *output); } bool HexStringToInt64(StringPiece input, int64_t* output) { - return IteratorRangeToNumber<HexIteratorRangeToInt64Traits>::Invoke( - input.begin(), input.end(), output); + return internal::HexStringToIntImpl(input, *output); } bool HexStringToUInt64(StringPiece input, uint64_t* output) { - return IteratorRangeToNumber<HexIteratorRangeToUInt64Traits>::Invoke( - input.begin(), input.end(), output); -} - -template <typename Container> -static bool HexStringToByteContainer(StringPiece input, Container* output) { - DCHECK_EQ(output->size(), 0u); - size_t count = input.size(); - if (count == 0 || (count % 2) != 0) - return false; - for (uintptr_t i = 0; i < count / 2; ++i) { - uint8_t msb = 0; // most significant 4 bits - uint8_t lsb = 0; // least significant 4 bits - if (!CharToDigit<16>(input[i * 2], &msb) || - !CharToDigit<16>(input[i * 2 + 1], &lsb)) { - return false; - } - output->push_back((msb << 4) | lsb); - } - return true; + return internal::HexStringToIntImpl(input, *output); } bool HexStringToBytes(StringPiece input, std::vector<uint8_t>* output) { - return HexStringToByteContainer(input, output); + DCHECK(output->empty()); + return internal::HexStringToByteContainer(input, std::back_inserter(*output)); } bool HexStringToString(StringPiece input, std::string* output) { - return HexStringToByteContainer(input, output); + DCHECK(output->empty()); + return internal::HexStringToByteContainer(input, std::back_inserter(*output)); } bool HexStringToSpan(StringPiece input, base::span<uint8_t> output) { - size_t count = input.size(); - if (count == 0 || (count % 2) != 0) + if (input.size() / 2 != output.size()) return false; - if (count / 2 != output.size()) - return false; - - for (uintptr_t i = 0; i < count / 2; ++i) { - uint8_t msb = 0; // most significant 4 bits - uint8_t lsb = 0; // least significant 4 bits - if (!CharToDigit<16>(input[i * 2], &msb) || - !CharToDigit<16>(input[i * 2 + 1], &lsb)) { - return false; - } - output[i] = (msb << 4) | lsb; - } - return true; + return internal::HexStringToByteContainer(input, output.begin()); } } // namespace base |