546 lines
16 KiB
C++
546 lines
16 KiB
C++
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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include "base/strings/string_number_conversions.h"
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#include <ctype.h>
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#include <errno.h>
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#include <stdlib.h>
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#include <wctype.h>
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#include <limits>
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#include <type_traits>
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#include "base/logging.h"
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#include "base/no_destructor.h"
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#include "base/numerics/safe_math.h"
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#include "base/strings/string_util.h"
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#include "base/strings/utf_string_conversions.h"
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#include "base/third_party/double_conversion/double-conversion/double-conversion.h"
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namespace base {
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namespace {
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template <typename STR, typename INT>
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struct IntToStringT {
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static STR IntToString(INT value) {
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// log10(2) ~= 0.3 bytes needed per bit or per byte log10(2**8) ~= 2.4.
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// So round up to allocate 3 output characters per byte, plus 1 for '-'.
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const size_t kOutputBufSize =
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3 * sizeof(INT) + std::numeric_limits<INT>::is_signed;
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// Create the string in a temporary buffer, write it back to front, and
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// then return the substr of what we ended up using.
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using CHR = typename STR::value_type;
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CHR outbuf[kOutputBufSize];
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// The ValueOrDie call below can never fail, because UnsignedAbs is valid
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// for all valid inputs.
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typename std::make_unsigned<INT>::type res =
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CheckedNumeric<INT>(value).UnsignedAbs().ValueOrDie();
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CHR* end = outbuf + kOutputBufSize;
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CHR* i = end;
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do {
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--i;
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DCHECK(i != outbuf);
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*i = static_cast<CHR>((res % 10) + '0');
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res /= 10;
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} while (res != 0);
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if (IsValueNegative(value)) {
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--i;
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DCHECK(i != outbuf);
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*i = static_cast<CHR>('-');
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}
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return STR(i, end);
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}
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};
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// Utility to convert a character to a digit in a given base
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template<typename CHAR, int BASE, bool BASE_LTE_10> class BaseCharToDigit {
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};
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// Faster specialization for bases <= 10
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template<typename CHAR, int BASE> class BaseCharToDigit<CHAR, BASE, true> {
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public:
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static bool Convert(CHAR c, uint8_t* digit) {
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if (c >= '0' && c < '0' + BASE) {
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*digit = static_cast<uint8_t>(c - '0');
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return true;
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}
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return false;
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}
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};
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// Specialization for bases where 10 < base <= 36
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template<typename CHAR, int BASE> class BaseCharToDigit<CHAR, BASE, false> {
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public:
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static bool Convert(CHAR c, uint8_t* digit) {
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if (c >= '0' && c <= '9') {
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*digit = c - '0';
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} else if (c >= 'a' && c < 'a' + BASE - 10) {
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*digit = c - 'a' + 10;
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} else if (c >= 'A' && c < 'A' + BASE - 10) {
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*digit = c - 'A' + 10;
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} else {
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return false;
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}
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return true;
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}
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};
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template <int BASE, typename CHAR>
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bool CharToDigit(CHAR c, uint8_t* digit) {
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return BaseCharToDigit<CHAR, BASE, BASE <= 10>::Convert(c, digit);
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}
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// There is an IsUnicodeWhitespace for wchars defined in string_util.h, but it
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// is locale independent, whereas the functions we are replacing were
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// locale-dependent. TBD what is desired, but for the moment let's not
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// introduce a change in behaviour.
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template<typename CHAR> class WhitespaceHelper {
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};
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template<> class WhitespaceHelper<char> {
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public:
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static bool Invoke(char c) {
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return 0 != isspace(static_cast<unsigned char>(c));
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}
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};
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template<> class WhitespaceHelper<char16> {
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public:
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static bool Invoke(char16 c) {
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return 0 != iswspace(c);
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}
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};
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template<typename CHAR> bool LocalIsWhitespace(CHAR c) {
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return WhitespaceHelper<CHAR>::Invoke(c);
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}
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// IteratorRangeToNumberTraits should provide:
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// - a typedef for iterator_type, the iterator type used as input.
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// - a typedef for value_type, the target numeric type.
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// - static functions min, max (returning the minimum and maximum permitted
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// values)
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// - constant kBase, the base in which to interpret the input
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template<typename IteratorRangeToNumberTraits>
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class IteratorRangeToNumber {
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public:
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typedef IteratorRangeToNumberTraits traits;
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typedef typename traits::iterator_type const_iterator;
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typedef typename traits::value_type value_type;
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// Generalized iterator-range-to-number conversion.
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//
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static bool Invoke(const_iterator begin,
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const_iterator end,
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value_type* output) {
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bool valid = true;
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while (begin != end && LocalIsWhitespace(*begin)) {
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valid = false;
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++begin;
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}
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if (begin != end && *begin == '-') {
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if (!std::numeric_limits<value_type>::is_signed) {
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*output = 0;
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valid = false;
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} else if (!Negative::Invoke(begin + 1, end, output)) {
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valid = false;
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}
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} else {
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if (begin != end && *begin == '+') {
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++begin;
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}
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if (!Positive::Invoke(begin, end, output)) {
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valid = false;
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}
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}
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return valid;
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}
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private:
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// Sign provides:
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// - a static function, CheckBounds, that determines whether the next digit
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// causes an overflow/underflow
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// - a static function, Increment, that appends the next digit appropriately
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// according to the sign of the number being parsed.
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template<typename Sign>
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class Base {
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public:
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static bool Invoke(const_iterator begin, const_iterator end,
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typename traits::value_type* output) {
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*output = 0;
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if (begin == end) {
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return false;
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}
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// Note: no performance difference was found when using template
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// specialization to remove this check in bases other than 16
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if (traits::kBase == 16 && end - begin > 2 && *begin == '0' &&
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(*(begin + 1) == 'x' || *(begin + 1) == 'X')) {
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begin += 2;
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}
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for (const_iterator current = begin; current != end; ++current) {
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uint8_t new_digit = 0;
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if (!CharToDigit<traits::kBase>(*current, &new_digit)) {
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return false;
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}
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if (current != begin) {
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if (!Sign::CheckBounds(output, new_digit)) {
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return false;
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}
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*output *= traits::kBase;
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}
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Sign::Increment(new_digit, output);
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}
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return true;
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}
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};
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class Positive : public Base<Positive> {
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public:
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static bool CheckBounds(value_type* output, uint8_t new_digit) {
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if (*output > static_cast<value_type>(traits::max() / traits::kBase) ||
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(*output == static_cast<value_type>(traits::max() / traits::kBase) &&
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new_digit > traits::max() % traits::kBase)) {
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*output = traits::max();
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return false;
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}
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return true;
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}
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static void Increment(uint8_t increment, value_type* output) {
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*output += increment;
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}
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};
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class Negative : public Base<Negative> {
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public:
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static bool CheckBounds(value_type* output, uint8_t new_digit) {
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if (*output < traits::min() / traits::kBase ||
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(*output == traits::min() / traits::kBase &&
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new_digit > 0 - traits::min() % traits::kBase)) {
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*output = traits::min();
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return false;
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}
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return true;
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}
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static void Increment(uint8_t increment, value_type* output) {
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*output -= increment;
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}
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};
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};
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template<typename ITERATOR, typename VALUE, int BASE>
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class BaseIteratorRangeToNumberTraits {
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public:
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typedef ITERATOR iterator_type;
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typedef VALUE value_type;
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static value_type min() {
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return std::numeric_limits<value_type>::min();
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}
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static value_type max() {
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return std::numeric_limits<value_type>::max();
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}
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static const int kBase = BASE;
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};
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template<typename ITERATOR>
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class BaseHexIteratorRangeToIntTraits
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: public BaseIteratorRangeToNumberTraits<ITERATOR, int, 16> {
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};
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template <typename ITERATOR>
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class BaseHexIteratorRangeToUIntTraits
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: public BaseIteratorRangeToNumberTraits<ITERATOR, uint32_t, 16> {};
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template <typename ITERATOR>
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class BaseHexIteratorRangeToInt64Traits
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: public BaseIteratorRangeToNumberTraits<ITERATOR, int64_t, 16> {};
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template <typename ITERATOR>
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class BaseHexIteratorRangeToUInt64Traits
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: public BaseIteratorRangeToNumberTraits<ITERATOR, uint64_t, 16> {};
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typedef BaseHexIteratorRangeToIntTraits<StringPiece::const_iterator>
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HexIteratorRangeToIntTraits;
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typedef BaseHexIteratorRangeToUIntTraits<StringPiece::const_iterator>
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HexIteratorRangeToUIntTraits;
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typedef BaseHexIteratorRangeToInt64Traits<StringPiece::const_iterator>
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HexIteratorRangeToInt64Traits;
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typedef BaseHexIteratorRangeToUInt64Traits<StringPiece::const_iterator>
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HexIteratorRangeToUInt64Traits;
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template <typename VALUE, int BASE>
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class StringPieceToNumberTraits
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: public BaseIteratorRangeToNumberTraits<StringPiece::const_iterator,
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VALUE,
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BASE> {
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};
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template <typename VALUE>
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bool StringToIntImpl(StringPiece input, VALUE* output) {
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return IteratorRangeToNumber<StringPieceToNumberTraits<VALUE, 10> >::Invoke(
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input.begin(), input.end(), output);
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}
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template <typename VALUE, int BASE>
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class StringPiece16ToNumberTraits
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: public BaseIteratorRangeToNumberTraits<StringPiece16::const_iterator,
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VALUE,
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BASE> {
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};
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template <typename VALUE>
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bool String16ToIntImpl(StringPiece16 input, VALUE* output) {
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return IteratorRangeToNumber<StringPiece16ToNumberTraits<VALUE, 10> >::Invoke(
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input.begin(), input.end(), output);
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}
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} // namespace
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std::string NumberToString(int value) {
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return IntToStringT<std::string, int>::IntToString(value);
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}
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string16 NumberToString16(int value) {
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return IntToStringT<string16, int>::IntToString(value);
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}
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std::string NumberToString(unsigned value) {
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return IntToStringT<std::string, unsigned>::IntToString(value);
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}
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string16 NumberToString16(unsigned value) {
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return IntToStringT<string16, unsigned>::IntToString(value);
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}
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std::string NumberToString(long value) {
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return IntToStringT<std::string, long>::IntToString(value);
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}
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string16 NumberToString16(long value) {
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return IntToStringT<string16, long>::IntToString(value);
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}
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std::string NumberToString(unsigned long value) {
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return IntToStringT<std::string, unsigned long>::IntToString(value);
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}
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string16 NumberToString16(unsigned long value) {
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return IntToStringT<string16, unsigned long>::IntToString(value);
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}
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std::string NumberToString(long long value) {
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return IntToStringT<std::string, long long>::IntToString(value);
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}
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string16 NumberToString16(long long value) {
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return IntToStringT<string16, long long>::IntToString(value);
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}
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std::string NumberToString(unsigned long long value) {
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return IntToStringT<std::string, unsigned long long>::IntToString(value);
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}
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string16 NumberToString16(unsigned long long value) {
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return IntToStringT<string16, unsigned long long>::IntToString(value);
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}
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static const double_conversion::DoubleToStringConverter*
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GetDoubleToStringConverter() {
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static NoDestructor<double_conversion::DoubleToStringConverter> converter(
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double_conversion::DoubleToStringConverter::EMIT_POSITIVE_EXPONENT_SIGN,
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nullptr, nullptr, 'e', -6, 12, 0, 0);
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return converter.get();
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}
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std::string NumberToString(double value) {
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char buffer[32];
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double_conversion::StringBuilder builder(buffer, sizeof(buffer));
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GetDoubleToStringConverter()->ToShortest(value, &builder);
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return std::string(buffer, builder.position());
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}
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base::string16 NumberToString16(double value) {
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char buffer[32];
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double_conversion::StringBuilder builder(buffer, sizeof(buffer));
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GetDoubleToStringConverter()->ToShortest(value, &builder);
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// The number will be ASCII. This creates the string using the "input
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// iterator" variant which promotes from 8-bit to 16-bit via "=".
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return base::string16(&buffer[0], &buffer[builder.position()]);
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}
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bool StringToInt(StringPiece input, int* output) {
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return StringToIntImpl(input, output);
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}
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bool StringToInt(StringPiece16 input, int* output) {
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return String16ToIntImpl(input, output);
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}
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bool StringToUint(StringPiece input, unsigned* output) {
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return StringToIntImpl(input, output);
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}
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bool StringToUint(StringPiece16 input, unsigned* output) {
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return String16ToIntImpl(input, output);
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}
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bool StringToInt64(StringPiece input, int64_t* output) {
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return StringToIntImpl(input, output);
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}
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bool StringToInt64(StringPiece16 input, int64_t* output) {
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return String16ToIntImpl(input, output);
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}
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bool StringToUint64(StringPiece input, uint64_t* output) {
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return StringToIntImpl(input, output);
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}
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bool StringToUint64(StringPiece16 input, uint64_t* output) {
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return String16ToIntImpl(input, output);
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}
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bool StringToSizeT(StringPiece input, size_t* output) {
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return StringToIntImpl(input, output);
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}
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bool StringToSizeT(StringPiece16 input, size_t* output) {
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return String16ToIntImpl(input, output);
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}
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template <typename STRING, typename CHAR>
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bool StringToDoubleImpl(STRING input, const CHAR* data, double* output) {
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static NoDestructor<double_conversion::StringToDoubleConverter> converter(
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double_conversion::StringToDoubleConverter::ALLOW_LEADING_SPACES |
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double_conversion::StringToDoubleConverter::ALLOW_TRAILING_JUNK,
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0.0, 0, nullptr, nullptr);
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int processed_characters_count;
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*output = converter->StringToDouble(data, input.size(),
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&processed_characters_count);
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// Cases to return false:
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// - If the input string is empty, there was nothing to parse.
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// - If the value saturated to HUGE_VAL.
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// - If the entire string was not processed, there are either characters
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// remaining in the string after a parsed number, or the string does not
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// 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]);
|
||
|
}
|
||
|
|
||
|
bool StringToDouble(StringPiece input, double* output) {
|
||
|
return StringToDoubleImpl(input, input.data(), output);
|
||
|
}
|
||
|
|
||
|
bool StringToDouble(StringPiece16 input, double* output) {
|
||
|
return StringToDoubleImpl(
|
||
|
input, reinterpret_cast<const uint16_t*>(input.data()), output);
|
||
|
}
|
||
|
|
||
|
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;
|
||
|
}
|
||
|
|
||
|
std::string HexEncode(base::span<const uint8_t> bytes) {
|
||
|
return HexEncode(bytes.data(), bytes.size());
|
||
|
}
|
||
|
|
||
|
bool HexStringToInt(StringPiece input, int* output) {
|
||
|
return IteratorRangeToNumber<HexIteratorRangeToIntTraits>::Invoke(
|
||
|
input.begin(), input.end(), output);
|
||
|
}
|
||
|
|
||
|
bool HexStringToUInt(StringPiece input, uint32_t* output) {
|
||
|
return IteratorRangeToNumber<HexIteratorRangeToUIntTraits>::Invoke(
|
||
|
input.begin(), input.end(), output);
|
||
|
}
|
||
|
|
||
|
bool HexStringToInt64(StringPiece input, int64_t* output) {
|
||
|
return IteratorRangeToNumber<HexIteratorRangeToInt64Traits>::Invoke(
|
||
|
input.begin(), input.end(), 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;
|
||
|
}
|
||
|
|
||
|
bool HexStringToBytes(StringPiece input, std::vector<uint8_t>* output) {
|
||
|
return HexStringToByteContainer(input, output);
|
||
|
}
|
||
|
|
||
|
bool HexStringToString(StringPiece input, std::string* output) {
|
||
|
return HexStringToByteContainer(input, output);
|
||
|
}
|
||
|
|
||
|
bool HexStringToSpan(StringPiece input, base::span<uint8_t> output) {
|
||
|
size_t count = input.size();
|
||
|
if (count == 0 || (count % 2) != 0)
|
||
|
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;
|
||
|
}
|
||
|
|
||
|
} // namespace base
|