Method writeJSONDouble

lib/cpp/src/thrift/protocol/TJSONProtocol.cpp:539–576

Convert the given double to a JSON string, which is either the number, "NaN" or "Infinity" or "-Infinity".

// Convert the given double to a JSON string, which is either the number,
// "NaN" or "Infinity" or "-Infinity".
uint32_t TJSONProtocol::writeJSONDouble(double num) {
  uint32_t result = context_->write(*trans_);
  std::string val;

  bool special = false;
  switch (std::fpclassify(num)) {
  case FP_INFINITE:
    if (std::signbit(num)) {
      val = kThriftNegativeInfinity;
    } else {
      val = kThriftInfinity;
    }
    special = true;
    break;
  case FP_NAN:
    val = kThriftNan;
    special = true;
    break;
  default:
    val = doubleToString(num);
    break;
  }

  bool escapeNum = special || context_->escapeNum();
  if (escapeNum) {
    trans_->write(&kJSONStringDelimiter, 1);
    result += 1;
  }
  if (val.length() > (std::numeric_limits<uint32_t>::max)())
    throw TProtocolException(TProtocolException::SIZE_LIMIT);
  trans_->write((const uint8_t*)val.c_str(), static_cast<uint32_t>(val.length()));
  result += static_cast<uint32_t>(val.length());
  if (escapeNum) {
    trans_->write(&kJSONStringDelimiter, 1);
    result += 1;
  }
  return result;
}

uint32_t TJSONProtocol::writeJSONObjectStart() {
  uint32_t result = context_->write(*trans_);