three_rates_modules-l-zmg/tr_queue.cpp

#include "tr_queue.h"
 
tr_queue::tr_queue(unsigned int size):m_nsize(size),m_nin(0),m_nout(0),m_pbuffer(nullptr)
{
	if (!is_power_of_2(size))
	{
		m_nsize = roundup_power_of_two(size);
	}
}
tr_queue::~tr_queue()
{
	if (nullptr != m_pbuffer)
	{
		delete[] m_pbuffer;
		m_pbuffer = nullptr;
	}
}
bool tr_queue::initialize()
{
	m_pbuffer = new unsigned char[m_nsize];
	if (!m_pbuffer)
		return false;
	m_nin = m_nout = 0;
	return true;
}
unsigned long tr_queue::roundup_power_of_two(unsigned long val)
{
	if ((val & (val-1)) == 0)
		return val;
	unsigned long maxulong = (unsigned long )((unsigned long ) ~0);
	unsigned long andv = ~(maxulong&(maxulong>>1));
	while((andv & val) == 0)
		andv = andv>>1;
	return andv<<1;
}
unsigned int tr_queue::get(unsigned char *_buffer, unsigned int len)
{
	unsigned int l;
	len = std::min(len, m_nin - m_nout);
	__sync_synchronize();
 
	l = std::min(len, m_nsize -(m_nout&(m_nsize-1)));
	memcpy(_buffer,m_pbuffer + (m_nout& (m_nsize-1)),l);
	memcpy(_buffer + l,m_pbuffer,len - l);
 
	 __sync_synchronize();
 
	 m_nout +=len;
	 return len;
 
}
unsigned int tr_queue::put(const unsigned char *_buffer, unsigned int len)
{
	unsigned int l;
	len = std::min(len, m_nsize - m_nin + m_nout);
	 __sync_synchronize();
	 l = std::min(len, m_nsize - (m_nin & (m_nsize - 1)));
	 memcpy(m_pbuffer + (m_nin & (m_nsize - 1)), _buffer, l);
	 memcpy(m_pbuffer, _buffer + l, len - l);
	  __sync_synchronize();
	 m_nin += len;
	 return len;
 
}