folly::io::compression::detail Namespace Reference

Functions
template<typename T >
std::enable_if< std::is_unsigned< T >::value, bool >::type	dataStartsWithLE (const IOBuf *data, T prefix, uint64_t n=sizeof(T))
template<typename T >
std::enable_if< std::is_arithmetic< T >::value, std::string >::type	prefixToStringLE (T prefix, uint64_t n=sizeof(T))

Function Documentation

template<typename T >

std::enable_if<std::is_unsigned<T>::value, bool>::type folly::io::compression::detail::dataStartsWithLE	(	const IOBuf *	data,
		T	prefix,
		uint64_t	n = sizeof(T)
	)

Reads sizeof(T) bytes, and returns false if not enough bytes are available. Returns true if the first n bytes are equal to prefix when interpreted as a little endian T.

Definition at line 40 of file Utils.h.

References string, folly::T, type, value, and folly::value().

Referenced by folly::io::StreamCodec::doUncompress().

                                                                      {
  DCHECK_GT(n, 0);
  DCHECK_LE(n, sizeof(T));
  T value;
  Cursor cursor{data};
  if (!cursor.tryReadLE(value)) {
    return false;
  }
  const T mask = n == sizeof(T) ? T(-1) : (T(1) << (8 * n)) - 1;
  return prefix == (value & mask);
}

template<typename T >

std::enable_if<std::is_arithmetic<T>::value, std::string>::type folly::io::compression::detail::prefixToStringLE	(	T	prefix,
		uint64_t	n = sizeof(T)
	)

Definition at line 54 of file Utils.h.

References folly::Endian::little(), string, and folly::T.

Referenced by folly::io::StreamCodec::doUncompress().

                                                   {
  DCHECK_GT(n, 0);
  DCHECK_LE(n, sizeof(T));
  prefix = Endian::little(prefix);
  std::string result;
  result.resize(n);
  memcpy(&result[0], &prefix, n);
  return result;
}