urbackup_backend/PipeThrottler.cpp

#include "PipeThrottler.h"
#include "Server.h"
#include "Interface/Mutex.h"

PipeThrottler::PipeThrottler(size_t bps)
	: throttle_bps(bps), curr_bytes(0), lastresettime(0)
{
	mutex=Server->createMutex();
}

PipeThrottler::~PipeThrottler(void)
{
	Server->destroy(mutex);
}

void PipeThrottler::addBytes(size_t new_bytes)
{
	IScopedLock lock(mutex);

	if(throttle_bps==0) return;

	unsigned int ctime=Server->getTimeMS();

	if(ctime-lastresettime>1000)
	{
		lastresettime=ctime;
		curr_bytes=0;
	}

	curr_bytes+=new_bytes;

	unsigned int passed_time=ctime-lastresettime;
	if(passed_time>0)
	{
		size_t bps=(size_t)(((_i64)curr_bytes*1000)/passed_time);
		if(bps>throttle_bps)
		{
			size_t maxRateTime=(size_t)(((_i64)curr_bytes*1000)/throttle_bps);
			unsigned int sleepTime=(unsigned int)(maxRateTime-passed_time);

			if(sleepTime>0)
			{
				Server->wait(sleepTime);

				if(Server->getTimeMS()-lastresettime>1000)
				{
					curr_bytes=0;
					lastresettime=Server->getTimeMS();
				}
			}
		}
	}
	else if(curr_bytes>=throttle_bps)
	{
		Server->wait(1000);
		curr_bytes=0;
		lastresettime=Server->getTimeMS();
	}
}

void PipeThrottler::changeThrottleLimit(size_t bps)
{
	IScopedLock lock(mutex);

	throttle_bps=bps;
}