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// Copyright (C) 2003 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_BIT_STREAM_KERNEL_1_CPp_
#define DLIB_BIT_STREAM_KERNEL_1_CPp_
#include "bit_stream_kernel_1.h"
#include "../algs.h"
#include <iostream>
namespace dlib
{
inline void swap (
bit_stream_kernel_1& a,
bit_stream_kernel_1& b
) { a.swap(b); }
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
// member function definitions
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
void bit_stream_kernel_1::
clear (
)
{
if (write_mode)
{
write_mode = false;
// flush output buffer
if (buffer_size > 0)
{
buffer <<= 8 - buffer_size;
osp->write(reinterpret_cast<char*>(&buffer),1);
}
}
else
read_mode = false;
}
// ----------------------------------------------------------------------------------------
void bit_stream_kernel_1::
set_input_stream (
std::istream& is
)
{
isp = &is;
read_mode = true;
buffer_size = 0;
}
// ----------------------------------------------------------------------------------------
void bit_stream_kernel_1::
set_output_stream (
std::ostream& os
)
{
osp = &os;
write_mode = true;
buffer_size = 0;
}
// ----------------------------------------------------------------------------------------
void bit_stream_kernel_1::
close (
)
{
if (write_mode)
{
write_mode = false;
// flush output buffer
if (buffer_size > 0)
{
buffer <<= 8 - buffer_size;
osp->write(reinterpret_cast<char*>(&buffer),1);
}
}
else
read_mode = false;
}
// ----------------------------------------------------------------------------------------
bool bit_stream_kernel_1::
is_in_write_mode (
) const
{
return write_mode;
}
// ----------------------------------------------------------------------------------------
bool bit_stream_kernel_1::
is_in_read_mode (
) const
{
return read_mode;
}
// ----------------------------------------------------------------------------------------
void bit_stream_kernel_1::
write (
int bit
)
{
// flush buffer if necessary
if (buffer_size == 8)
{
buffer <<= 8 - buffer_size;
if (osp->rdbuf()->sputn(reinterpret_cast<char*>(&buffer),1) == 0)
{
throw std::ios_base::failure("error occurred in the bit_stream object");
}
buffer_size = 0;
}
++buffer_size;
buffer <<= 1;
buffer += static_cast<unsigned char>(bit);
}
// ----------------------------------------------------------------------------------------
bool bit_stream_kernel_1::
read (
int& bit
)
{
// get new byte if necessary
if (buffer_size == 0)
{
if (isp->rdbuf()->sgetn(reinterpret_cast<char*>(&buffer), 1) == 0)
{
// if we didn't read anything then return false
return false;
}
buffer_size = 8;
}
// put the most significant bit from buffer into bit
bit = static_cast<int>(buffer >> 7);
// shift out the bit that was just read
buffer <<= 1;
--buffer_size;
return true;
}
// ----------------------------------------------------------------------------------------
void bit_stream_kernel_1::
swap (
bit_stream_kernel_1& item
)
{
std::istream* isp_temp = item.isp;
std::ostream* osp_temp = item.osp;
bool write_mode_temp = item.write_mode;
bool read_mode_temp = item.read_mode;
unsigned char buffer_temp = item.buffer;
unsigned short buffer_size_temp = item.buffer_size;
item.isp = isp;
item.osp = osp;
item.write_mode = write_mode;
item.read_mode = read_mode;
item.buffer = buffer;
item.buffer_size = buffer_size;
isp = isp_temp;
osp = osp_temp;
write_mode = write_mode_temp;
read_mode = read_mode_temp;
buffer = buffer_temp;
buffer_size = buffer_size_temp;
}
// ----------------------------------------------------------------------------------------
}
#endif // DLIB_BIT_STREAM_KERNEL_1_CPp_
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