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dvmfirmware-hs/BitBuffer.cpp

113 lines
2.2 KiB

// SPDX-License-Identifier: GPL-2.0-only
/*
* Digital Voice Modem - Hotspot Firmware
* GPLv2 Open Source. Use is subject to license terms.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* Copyright (C) 2015,2016 Jonathan Naylor, G4KLX
* Serial FIFO Control Copyright (C) 2015 by James McLaughlin, KI6ZUM
*
*/
#include "BitBuffer.h"
// ---------------------------------------------------------------------------
// Public Class Members
// ---------------------------------------------------------------------------
/* Initializes a new instance of the BitBuffer class. */
BitBuffer::BitBuffer(uint16_t length) :
m_length(length),
m_bits(NULL),
m_control(NULL),
m_head(0U),
m_tail(0U),
m_full(false),
m_overflow(false)
{
m_bits = new uint8_t[length / 8U];
m_control = new uint8_t[length / 8U];
}
/* Helper to get how much space the ring buffer has for samples. */
uint16_t BitBuffer::getSpace() const
{
uint16_t n = 0U;
if (m_tail == m_head)
n = m_full ? 0U : m_length;
else if (m_tail < m_head)
n = m_length - m_head + m_tail;
else
n = m_tail - m_head;
if (n > m_length)
n = 0U;
return n;
}
/* */
uint16_t BitBuffer::getData() const
{
if (m_tail == m_head)
return m_full ? m_length : 0U;
else if (m_tail < m_head)
return m_head - m_tail;
else
return m_length - m_tail + m_head;
}
/* */
bool BitBuffer::put(uint8_t bit, uint8_t control)
{
if (m_full) {
m_overflow = true;
return false;
}
_WRITE_BIT(m_bits, m_head, bit);
_WRITE_BIT(m_control, m_head, control);
m_head++;
if (m_head >= m_length)
m_head = 0U;
if (m_head == m_tail)
m_full = true;
return true;
}
/* */
bool BitBuffer::get(uint8_t& bit, uint8_t& control)
{
if (m_head == m_tail && !m_full)
return false;
bit = _READ_BIT(m_bits, m_tail);
control = _READ_BIT(m_control, m_tail);
m_full = false;
m_tail++;
if (m_tail >= m_length)
m_tail = 0U;
return true;
}
/* */
bool BitBuffer::hasOverflowed()
{
bool overflow = m_overflow;
m_overflow = false;
return overflow;
}

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