void sprintf_format()

in src/main/cpp/sdk/common/spdlog/fmt/bundled/format-inl.h [764:805]

• 35 lines of code
• 7 McCabe index (conditional complexity)

void sprintf_format(Double value, internal::buffer &buf,
                    core_format_specs spec) {
  // Buffer capacity must be non-zero, otherwise MSVC's vsnprintf_s will fail.
  FMT_ASSERT(buf.capacity() != 0, "empty buffer");

  // Build format string.
  enum { MAX_FORMAT_SIZE = 10}; // longest format: %#-*.*Lg
  char format[MAX_FORMAT_SIZE];
  char *format_ptr = format;
  *format_ptr++ = '%';
  if (spec.has(HASH_FLAG))
    *format_ptr++ = '#';
  if (spec.precision >= 0) {
    *format_ptr++ = '.';
    *format_ptr++ = '*';
  }
  if (std::is_same<Double, long double>::value)
    *format_ptr++ = 'L';
  *format_ptr++ = spec.type;
  *format_ptr = '\0';

  // Format using snprintf.
  char *start = FMT_NULL;
  for (;;) {
    std::size_t buffer_size = buf.capacity();
    start = &buf[0];
    int result = internal::char_traits<char>::format_float(
        start, buffer_size, format, spec.precision, value);
    if (result >= 0) {
      unsigned n = internal::to_unsigned(result);
      if (n < buf.capacity()) {
        buf.resize(n);
        break;  // The buffer is large enough - continue with formatting.
      }
      buf.reserve(n + 1);
    } else {
      // If result is negative we ask to increase the capacity by at least 1,
      // but as std::vector, the buffer grows exponentially.
      buf.reserve(buf.capacity() + 1);
    }
  }
}