| // Copyright 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/string_number_conversions.h" |
| |
| #include <ctype.h> |
| #include <stdint.h> |
| |
| #include <limits> |
| |
| namespace base { |
| |
| namespace { |
| |
| template<typename CHAR, int BASE, bool BASE_LTE_10> |
| class BaseCharToDigit { |
| }; |
| |
| 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 = c - '0'; |
| return true; |
| } |
| return false; |
| } |
| }; |
| |
| 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); |
| } |
| |
| 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); |
| } |
| |
| template<typename IteratorRangeToNumberTraits> |
| class IteratorRangeToNumber { |
| public: |
| typedef IteratorRangeToNumberTraits traits; |
| typedef typename traits::iterator_type const_iterator; |
| typedef typename traits::value_type value_type; |
| |
| 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 (!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: |
| 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; |
| } |
| |
| 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; |
| }; |
| |
| typedef BaseIteratorRangeToNumberTraits<StringPiece::const_iterator, int, 10> |
| IteratorRangeToIntTraits; |
| |
| typedef BaseIteratorRangeToNumberTraits<StringPiece::const_iterator, |
| unsigned int, |
| 10> |
| IteratorRangeToUintTraits; |
| |
| typedef BaseIteratorRangeToNumberTraits<StringPiece::const_iterator, |
| int64_t, |
| 10> |
| IteratorRangeToInt64Traits; |
| |
| typedef BaseIteratorRangeToNumberTraits<StringPiece::const_iterator, |
| uint64_t, |
| 10> |
| IteratorRangeToUint64Traits; |
| |
| typedef BaseIteratorRangeToNumberTraits<StringPiece::const_iterator, |
| size_t, |
| 10> |
| IteratorRangeToSizeTTraits; |
| |
| template<typename ITERATOR> |
| class BaseHexIteratorRangeToIntTraits |
| : public BaseIteratorRangeToNumberTraits<ITERATOR, int, 16> { |
| public: |
| static unsigned int max() { |
| return std::numeric_limits<unsigned int>::max(); |
| } |
| }; |
| |
| typedef BaseHexIteratorRangeToIntTraits<StringPiece::const_iterator> |
| HexIteratorRangeToIntTraits; |
| |
| } // namespace |
| |
| bool StringToInt(const StringPiece& input, int* output) { |
| return IteratorRangeToNumber<IteratorRangeToIntTraits>::Invoke(input.begin(), |
| input.end(), |
| output); |
| } |
| |
| bool StringToUint(const StringPiece& input, unsigned int* output) { |
| return IteratorRangeToNumber<IteratorRangeToUintTraits>::Invoke(input.begin(), |
| input.end(), |
| output); |
| } |
| |
| bool StringToInt64(const StringPiece& input, int64_t* output) { |
| return IteratorRangeToNumber<IteratorRangeToInt64Traits>::Invoke( |
| input.begin(), input.end(), output); |
| } |
| |
| bool StringToUint64(const StringPiece& input, uint64_t* output) { |
| return IteratorRangeToNumber<IteratorRangeToUint64Traits>::Invoke( |
| input.begin(), input.end(), output); |
| } |
| |
| bool StringToSizeT(const StringPiece& input, size_t* output) { |
| return IteratorRangeToNumber<IteratorRangeToSizeTTraits>::Invoke( |
| input.begin(), input.end(), output); |
| } |
| |
| bool HexStringToInt(const StringPiece& input, int* output) { |
| return IteratorRangeToNumber<HexIteratorRangeToIntTraits>::Invoke( |
| input.begin(), input.end(), output); |
| } |
| |
| bool HexStringToBytes(const std::string& input, std::vector<uint8_t>* output) { |
| size_t count = input.size(); |
| if (count == 0 || (count % 2) != 0) { |
| return false; |
| } |
| for (size_t i = 0; i < count; i += 2) { |
| uint8_t msb = 0; |
| uint8_t lsb = 0; |
| if (!CharToDigit<16>(input[i], &msb) || |
| !CharToDigit<16>(input[i + 1], &lsb)) { |
| return false; |
| } |
| output->push_back((msb << 4) | lsb); |
| } |
| return true; |
| } |
| |
| } // namespace base |