| // Copyright (c) 2012 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/string_number_conversions.h" |
| |
| #include <ctype.h> |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <wctype.h> |
| |
| #include <limits> |
| |
| #include "base/logging.h" |
| #include "base/numerics/safe_conversions.h" |
| #include "base/numerics/safe_math.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. |
| auto 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<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 STR> |
| bool HexStringToBytesT(const STR& input, std::vector<uint8_t>* 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; |
| } |
| |
| template <typename VALUE, int BASE> |
| class StringPieceToNumberTraits |
| : public BaseIteratorRangeToNumberTraits<StringPiece::const_iterator, |
| VALUE, |
| BASE> { |
| }; |
| |
| template <typename VALUE> |
| bool StringToIntImpl(const StringPiece& input, VALUE* output) { |
| return IteratorRangeToNumber<StringPieceToNumberTraits<VALUE, 10> >::Invoke( |
| input.begin(), input.end(), output); |
| } |
| |
| } // namespace |
| |
| std::string IntToString(int value) { |
| return IntToStringT<std::string, int>::IntToString(value); |
| } |
| |
| std::string UintToString(unsigned int value) { |
| return IntToStringT<std::string, unsigned int>::IntToString(value); |
| } |
| |
| std::string Int64ToString(int64_t value) { |
| return IntToStringT<std::string, int64_t>::IntToString(value); |
| } |
| |
| std::string Uint64ToString(uint64_t value) { |
| return IntToStringT<std::string, uint64_t>::IntToString(value); |
| } |
| |
| std::string SizeTToString(size_t value) { |
| return IntToStringT<std::string, size_t>::IntToString(value); |
| } |
| |
| std::string DoubleToString(double value) { |
| auto ret = std::to_string(value); |
| // If this returned an integer, don't do anything. |
| if (ret.find('.') == std::string::npos) { |
| return ret; |
| } |
| // Otherwise, it has an annoying tendency to leave trailing zeros. |
| size_t len = ret.size(); |
| while (len >= 2 && ret[len - 1] == '0' && ret[len - 2] != '.') { |
| --len; |
| } |
| ret.erase(len); |
| return ret; |
| } |
| |
| bool StringToInt(const StringPiece& input, int* output) { |
| return StringToIntImpl(input, output); |
| } |
| |
| bool StringToUint(const StringPiece& input, unsigned* output) { |
| return StringToIntImpl(input, output); |
| } |
| |
| bool StringToInt64(const StringPiece& input, int64_t* output) { |
| return StringToIntImpl(input, output); |
| } |
| |
| bool StringToUint64(const StringPiece& input, uint64_t* output) { |
| return StringToIntImpl(input, output); |
| } |
| |
| bool StringToSizeT(const StringPiece& input, size_t* output) { |
| return StringToIntImpl(input, output); |
| } |
| |
| bool StringToDouble(const std::string& input, double* output) { |
| char* endptr = nullptr; |
| *output = strtod(input.c_str(), &endptr); |
| |
| // Cases to return false: |
| // - 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. |
| // - If the first character is a space, there was leading whitespace |
| return !input.empty() && |
| input.c_str() + input.length() == endptr && |
| !isspace(input[0]) && |
| *output != std::numeric_limits<double>::infinity() && |
| *output != -std::numeric_limits<double>::infinity(); |
| } |
| |
| // Note: if you need to add String16ToDouble, first ask yourself if it's |
| // really necessary. If it is, probably the best implementation here is to |
| // convert to 8-bit and then use the 8-bit version. |
| |
| // Note: if you need to add an iterator range version of StringToDouble, first |
| // ask yourself if it's really necessary. If it is, probably the best |
| // implementation here is to instantiate a string and use the string version. |
| |
| std::string HexEncode(const void* bytes, size_t size) { |
| static const char kHexChars[] = "0123456789ABCDEF"; |
| |
| // Each input byte creates two output hex characters. |
| std::string ret(size * 2, '\0'); |
| |
| for (size_t i = 0; i < size; ++i) { |
| char b = reinterpret_cast<const char*>(bytes)[i]; |
| ret[(i * 2)] = kHexChars[(b >> 4) & 0xf]; |
| ret[(i * 2) + 1] = kHexChars[b & 0xf]; |
| } |
| return ret; |
| } |
| |
| bool HexStringToInt(const StringPiece& input, int* output) { |
| return IteratorRangeToNumber<HexIteratorRangeToIntTraits>::Invoke( |
| input.begin(), input.end(), output); |
| } |
| |
| bool HexStringToUInt(const StringPiece& input, uint32_t* output) { |
| return IteratorRangeToNumber<HexIteratorRangeToUIntTraits>::Invoke( |
| input.begin(), input.end(), output); |
| } |
| |
| bool HexStringToInt64(const StringPiece& input, int64_t* output) { |
| return IteratorRangeToNumber<HexIteratorRangeToInt64Traits>::Invoke( |
| input.begin(), input.end(), output); |
| } |
| |
| bool HexStringToUInt64(const StringPiece& input, uint64_t* output) { |
| return IteratorRangeToNumber<HexIteratorRangeToUInt64Traits>::Invoke( |
| input.begin(), input.end(), output); |
| } |
| |
| bool HexStringToBytes(const std::string& input, std::vector<uint8_t>* output) { |
| return HexStringToBytesT(input, output); |
| } |
| |
| } // namespace base |