flutter_flutter/sky/engine/wtf/text/IntegerToStringConversion.h

/*
 * Copyright (C) 2012 Apple Inc. All Rights Reserved.
 * Copyright (C) 2012 Patrick Gansterer <paroga@paroga.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef SKY_ENGINE_WTF_TEXT_INTEGERTOSTRINGCONVERSION_H_
#define SKY_ENGINE_WTF_TEXT_INTEGERTOSTRINGCONVERSION_H_

#include "flutter/sky/engine/wtf/text/StringBuilder.h"
#include "flutter/sky/engine/wtf/text/StringImpl.h"

namespace WTF {

enum PositiveOrNegativeNumber { PositiveNumber, NegativeNumber };

template <typename T>
struct ConversionTrait;

template <>
struct ConversionTrait<String> {
  typedef PassRefPtr<StringImpl> ReturnType;
  typedef void AdditionalArgumentType;
  static inline ReturnType flush(LChar* characters, unsigned length, void*) {
    return StringImpl::create(characters, length);
  }
};
template <>
struct ConversionTrait<StringBuilder> {
  typedef void ReturnType;
  typedef StringBuilder AdditionalArgumentType;
  static inline ReturnType flush(LChar* characters,
                                 unsigned length,
                                 StringBuilder* stringBuilder) {
    stringBuilder->append(characters, length);
  }
};
template <>
struct ConversionTrait<AtomicString> {
  typedef AtomicString ReturnType;
  typedef void AdditionalArgumentType;
  static inline ReturnType flush(LChar* characters, unsigned length, void*) {
    return AtomicString(characters, length);
  }
};

template <typename T>
struct UnsignedIntegerTrait;

template <>
struct UnsignedIntegerTrait<int> {
  typedef unsigned Type;
};
template <>
struct UnsignedIntegerTrait<long> {
  typedef unsigned long Type;
};
template <>
struct UnsignedIntegerTrait<long long> {
  typedef unsigned long long Type;
};

template <typename T,
          typename UnsignedIntegerType,
          PositiveOrNegativeNumber NumberType>
static typename ConversionTrait<T>::ReturnType numberToStringImpl(
    UnsignedIntegerType number,
    typename ConversionTrait<T>::AdditionalArgumentType* additionalArgument) {
  LChar buf[sizeof(UnsignedIntegerType) * 3 + 1];
  LChar* end = buf + WTF_ARRAY_LENGTH(buf);
  LChar* p = end;

  do {
    *--p = static_cast<LChar>((number % 10) + '0');
    number /= 10;
  } while (number);

  if (NumberType == NegativeNumber)
    *--p = '-';

  return ConversionTrait<T>::flush(p, static_cast<unsigned>(end - p),
                                   additionalArgument);
}

template <typename T, typename SignedIntegerType>
inline typename ConversionTrait<T>::ReturnType numberToStringSigned(
    SignedIntegerType number,
    typename ConversionTrait<T>::AdditionalArgumentType* additionalArgument =
        0) {
  if (number < 0)
    return numberToStringImpl<
        T, typename UnsignedIntegerTrait<SignedIntegerType>::Type,
        NegativeNumber>(-number, additionalArgument);
  return numberToStringImpl<
      T, typename UnsignedIntegerTrait<SignedIntegerType>::Type,
      PositiveNumber>(number, additionalArgument);
}

template <typename T, typename UnsignedIntegerType>
inline typename ConversionTrait<T>::ReturnType numberToStringUnsigned(
    UnsignedIntegerType number,
    typename ConversionTrait<T>::AdditionalArgumentType* additionalArgument =
        0) {
  return numberToStringImpl<T, UnsignedIntegerType, PositiveNumber>(
      number, additionalArgument);
}

}  // namespace WTF

#endif  // SKY_ENGINE_WTF_TEXT_INTEGERTOSTRINGCONVERSION_H_