P2P编程

开发平台：
Visual C++

Choker.cpp：源码内容
							// Choker.cpp: implementation of the CChoker class.
//
//////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include "testbt.h"
#include "Choker.h"
#include "Connection.h"
#include "Upload.h"
#include "SingleDownload.h"
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif
#define TIME_ROUND_ROBIN 10 //number of seconds to pause between round_robin.
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
CChoker::CChoker(long lMaxUploads, HANDLE hevDone)
{
	m_lMaxUploads = lMaxUploads;
	m_hevDone = hevDone;
	m_lCount = 0;
	time(&m_tRoundRobin);
	_test();
}
CChoker::~CChoker()
{
}
void CChoker::connection_made(CConnection *pConnection)
{
	m_connections.push_back(pConnection);
	_rechoke();
}
void CChoker::connection_lost(CConnection *pConnection)
{
	vector<CConnection*>::iterator it = find(m_connections.begin(), m_connections.end(), pConnection);
	assert(it != m_connections.end());
	m_connections.erase(it);
	if ((*it)->m_pUpload->is_interested() && !(*it)->m_pUpload->is_choked())
		_rechoke();
}
void CChoker::interested(CConnection *pConnection)
{
	vector<CConnection*>::iterator it = find(m_connections.begin(), m_connections.end(), pConnection);
	assert(it != m_connections.end());
	if (!(*it)->m_pUpload->is_choked())
		_rechoke();
}
void CChoker::not_interested(CConnection *pConnection)
{
	vector<CConnection*>::iterator it = find(m_connections.begin(), m_connections.end(), pConnection);
	assert(it != m_connections.end());
	if (!(*it)->m_pUpload->is_choked())
		_rechoke();
}
bool CChoker::_snubbed(CConnection *pConnection)
{
	if (IsEventSet(m_hevDone))
		return false;
	return pConnection->m_pDownload->is_snubbed();
}
long CChoker::_rate(CConnection *pConnection)
{
	if (IsEventSet(m_hevDone))
		return pConnection->m_pUpload->get_rate();
	else
		return pConnection->m_pDownload->get_rate();
}
void CChoker::printitem(CPreferItem& item)
{
	TRACE("(%d,%d)", item.m_lrate, item.m_pConnection);
}
void CChoker::_rechoke()
{
	vector<CPreferItem> vPreferred;
	for (int i=0; i<m_connections.size(); i++)
		if (!_snubbed(m_connections[i]) && m_connections[i]->m_pUpload->is_interested())
		{
			vPreferred.push_back(CPreferItem(_rate(m_connections[i]), m_connections[i]));
		}
	sort(vPreferred.begin(), vPreferred.end(), greater<CPreferItem&>());
	if (vPreferred.size() > m_lMaxUploads)
		vPreferred.erase(vPreferred.begin() + m_lMaxUploads, vPreferred.end());
	long lCount = vPreferred.size();
	/*
	TRACE("rn_rechoke() {");
	for_each(vPreferred.begin(), vPreferred.end(), printitem);
	TRACE("}rn");
	//*/
	for (i=0; i<m_connections.size(); i++)
	{
		CUpload* pu = m_connections[i]->m_pUpload;
		bool bfind = false;
		for (int j=0; j<vPreferred.size(); j++)
			if (m_connections[i] == vPreferred[j].m_pConnection)
			{
				bfind = true;
				break;
			}
		if (bfind)
			pu->unchoke();
		else
		{
			if (lCount < m_lMaxUploads)
			{
				pu->unchoke();
				if (pu->is_interested())
					lCount ++;
			}
			else
				pu->choke();
		}
	}
}
time_t CChoker::round_robin()
{
	time_t t;
	time(&t);
	time_t tspan = t - m_tRoundRobin;
	assert(tspan >= 0);
	if (tspan < 0)
		m_tRoundRobin = t;
	if (tspan < TIME_ROUND_ROBIN)
		return TIME_ROUND_ROBIN - tspan;
	// TRACE("round_robin() ");
	_round_robin();
	time(&m_tRoundRobin);
	return TIME_ROUND_ROBIN;
}
void CChoker::_round_robin()
{
	m_lCount++;
	if (m_lCount%3 == 0)
	{
		for (int i=0; i<m_connections.size(); i++)
		{
			CUpload* pu = m_connections[i]->m_pUpload;
			if (pu->is_choked() && pu->is_interested())
			{
				rotate(m_connections.begin(), m_connections.begin() + i, m_connections.end());
				break;
			}
		}
	}
	_rechoke();
}
void CChoker::SetMaxUploads(long lMaxUploads)
{
	if (lMaxUploads <= 0)
	{
		assert(false);
		return;
	}
	m_lMaxUploads = lMaxUploads;
}
void printl(CConnection* l)
{
	TRACE("%d, ", l);
}
void CChoker::_test()
{	
	/*
	for (int i=0; i<5; i++)
	{
		m_connections.push_back((CConnection*)i);
	}
	
	TRACE("rn{");
	for_each(m_connections.begin(), m_connections.end(), printl);
	TRACE("}rn");
	rotate(m_connections.begin(), m_connections.begin() + 2, m_connections.end());
	// iter_swap(m_connections.begin() + 4, m_connections.begin() + 2);
	/*
	CConnection* pold = m_connections[4];
	m_connections[4] = m_connections[2];
	m_connections[2] = pold;
	
	
	
	TRACE("rn{");
	for_each(m_connections.begin(), m_connections.end(), printl);
	TRACE("}rn");//*/
	/*
	for (int i=0; i<100; i++)
	{
		Sleep(3000);
		time_t td = round_robin();
		TRACE("time delay %drn", td);
	}
	int ii = 0;
	//*/
	// _rechoke();
}

						