This class is made to help writing datas of custom bit length. More...

#include <bit_ostream.hpp>

Public Member Functions
	bit_ostream (stream_type &f)
	Constructor.
	~bit_ostream ()
	Destructor.
void	write (const char *buf, unsigned int n)
	Write some bits.
Private Types
typedef Stream	stream_type
	The type of the stream we will write.
Private Attributes
stream_type &	m_stream
	The stream we're reading.
unsigned char	m_pending
	Some bits available for writing.
unsigned char	m_pending_length
	The number of valid bits in m_pending.

Detailed Description

template<typename Stream>
class claw::bit_ostream< Stream >

This class is made to help writing datas of custom bit length.

Author:: Julien Jorge

Definition at line 40 of file bit_ostream.hpp.

Member Typedef Documentation

template<typename Stream >

typedef Stream claw::bit_ostream< Stream >::stream_type [private]

The type of the stream we will write.

Definition at line 44 of file bit_ostream.hpp.

Constructor & Destructor Documentation

template<typename Stream >

claw::bit_ostream< Stream >::bit_ostream ( stream_type & f )

Constructor.

Parameters:

f

The stream in which we write.

Definition at line 38 of file bit_ostream.tpp.

  : m_stream(f), m_pending(0), m_pending_length(0)
{

} // bit_ostream::bit_ostream()

template<typename Stream >

claw::bit_ostream< Stream >::~bit_ostream ( )

Destructor.

Definition at line 49 of file bit_ostream.tpp.

References claw::bit_ostream< Stream >::m_pending, claw::bit_ostream< Stream >::m_pending_length, and claw::bit_ostream< Stream >::m_stream.

{
  if (m_pending_length != 0)
    m_stream.write( (char*)&m_pending, sizeof(m_pending) );
} // bit_ostream::~bit_ostream()

Member Function Documentation

template<typename Stream >

void claw::bit_ostream< Stream >::write	(	const char *	buf,
		unsigned int	n
	)

Write some bits.

Parameters:

	buf	A buffer from which we read the bits.
	n	The number of bits to write.

Definition at line 62 of file bit_ostream.tpp.

References claw::bit_ostream< Stream >::m_pending, claw::bit_ostream< Stream >::m_pending_length, and claw::bit_ostream< Stream >::m_stream.

{
  if ( n == 0 )
    return;

  unsigned int cur_size = 0;
  unsigned char data = *buf;

  while ( n != 0 )
    {
      while( (m_pending_length != CHAR_BIT) && (n!=0) )
        {
          unsigned int bits =
            std::min(CHAR_BIT - (unsigned int)m_pending_length, n);

          if ( CHAR_BIT - cur_size < bits )
            bits = CHAR_BIT - cur_size;

          unsigned int mask = (1 << bits) - 1;

          m_pending |= (data & mask) << m_pending_length;
          cur_size += bits;
          m_pending_length += bits;
          data >>= bits;
          n -= bits;

          if ( (cur_size == CHAR_BIT) && (n!=0) )
            {
              ++buf;
              cur_size = 0;
              data = *buf;
            }
        }

      if ( m_pending_length == CHAR_BIT )
        {
          m_stream.write( (char*)&m_pending, sizeof(m_pending) );
          m_pending = 0;
          m_pending_length = 0;
        }
    }
} // bit_ostream::write()