RetroShare/libretroshare/src/pqi/pqiqos.cc
2011-09-08 19:22:50 +00:00

80 lines
1.8 KiB
C++

#include <iostream>
#include <list>
#include <math.h>
#include <serialiser/rsserial.h>
#include "pqiqos.h"
pqiQoS::pqiQoS(uint32_t nb_levels,float alpha)
: _item_queues(nb_levels),_alpha(alpha)
{
assert(pow(alpha,nb_levels) < 1e+20) ;
float c = 1.0f ;
float inc = alpha ;
_nb_items = 0 ;
for(int i=((int)nb_levels)-1;i>=0;--i,c *= alpha)
{
_item_queues[i]._threshold = c ;
_item_queues[i]._counter = 0 ;
_item_queues[i]._inc = inc ;
}
}
void pqiQoS::print() const
{
std::cerr << "pqiQoS: " << _item_queues.size() << " levels, alpha=" << _alpha ;
std::cerr << " Size = " << _nb_items ;
std::cerr << " Queues: " ;
for(uint32_t i=0;i<_item_queues.size();++i)
std::cerr << _item_queues[i]._items.size() << " " ;
std::cerr << std::endl;
}
void pqiQoS::in_rsItem(RsItem *item)
{
if(item->priority_level() >= _item_queues.size())
{
std::cerr << "pqiQoS::in_rsRawItem() ****Warning****: priority " << item->priority_level() << " out of scope [0," << _item_queues.size()-1 << "]. Priority will be clamped to maximum value." << std::endl;
item->setPriorityLevel(_item_queues.size()-1) ;
}
_item_queues[item->priority_level()].push(item) ;
++_nb_items ;
}
RsItem *pqiQoS::out_rsItem()
{
// Go through the queues. Increment counters.
if(_nb_items == 0)
return NULL ;
float inc = 1.0f ;
int i = _item_queues.size()-1 ;
while(i > 0 && _item_queues[i]._items.empty())
--i, inc = _item_queues[i]._inc ;
int last = i ;
for(int j=i;j>=0;--j)
if( (!_item_queues[j]._items.empty()) && ((_item_queues[j]._counter += inc) >= _item_queues[j]._threshold ))
{
last = j ;
_item_queues[j]._counter -= _item_queues[j]._threshold ;
}
if(last >= 0)
{
assert(_nb_items > 0) ;
--_nb_items ;
return _item_queues[last].pop();
}
else
return NULL ;
}