pongcache.cpp

著名的下载软件核心Shareaza

//
// PongCache.cpp
//
// Copyright (c) Shareaza Development Team, 2002-2004.
// This file is part of SHAREAZA (www.shareaza.com)
//
// Shareaza is free software; you can redistribute it
// and/or modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2 of
// the License, or (at your option) any later version.
//
// Shareaza is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Shareaza; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//

#include "StdAfx.h"
#include "Shareaza.h"
#include "Settings.h"
#include "PongCache.h"
#include "G1Packet.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif


//////////////////////////////////////////////////////////////////////
// CPongCache construction

CPongCache::CPongCache()
{
	m_nTime = 0;
}

CPongCache::~CPongCache()
{
	Clear();
}

//////////////////////////////////////////////////////////////////////
// CPongCache clear

void CPongCache::Clear()
{
	for ( POSITION pos = m_pCache.GetHeadPosition() ; pos ; )
	{
		CPongItem* pItem = (CPongItem*)m_pCache.GetNext( pos );
		delete pItem;
	}

	m_pCache.RemoveAll();

	m_nTime = GetTickCount();
}

BOOL CPongCache::ClearIfOld()
{
	if ( GetTickCount() - m_nTime >= Settings.Gnutella1.PongCache )
	{
		Clear();
		return TRUE;
	}

	return FALSE;
}

//////////////////////////////////////////////////////////////////////
// CPongCache add

CPongItem* CPongCache::Add(CNeighbour* pNeighbour, IN_ADDR* pAddress, WORD nPort, BYTE nHops, DWORD nFiles, DWORD nVolume)
{
	for ( POSITION pos = m_pCache.GetHeadPosition() ; pos ; )
	{
		CPongItem* pItem = (CPongItem*)m_pCache.GetNext( pos );

		if ( pItem->m_nPort != nPort ) continue;
		if ( pItem->m_nHops != nHops ) continue;
		
		if ( memcmp( &pItem->m_pAddress, pAddress, sizeof(IN_ADDR) ) == 0 )
		{
			pItem->m_nFiles		= nFiles;
			pItem->m_nVolume	= nVolume;
			return pItem;
		}
	}

	CPongItem* pItem = new CPongItem( pNeighbour, pAddress, nPort, nHops, nFiles, nVolume );

	m_pCache.AddTail( pItem );

	return pItem;
}

//////////////////////////////////////////////////////////////////////
// CPongCache lookup

CPongItem* CPongCache::Lookup(CNeighbour* pNotFrom, BYTE nHops, CPtrList* pIgnore)
{
	for ( POSITION pos = m_pCache.GetHeadPosition() ; pos ; )
	{
		CPongItem* pItem = (CPongItem*)m_pCache.GetNext( pos );

		if ( pItem->m_nHops != nHops ) continue;
		if ( pItem->m_pNeighbour == pNotFrom ) continue;

		if ( pIgnore && pIgnore->Find( pItem ) ) continue;
		
		return pItem;
	}

	return NULL;
}

//////////////////////////////////////////////////////////////////////
// CPongCache list access

POSITION CPongCache::GetIterator() const
{
	return m_pCache.GetHeadPosition();
}

CPongItem* CPongCache::GetNext(POSITION& pos) const
{
	return (CPongItem*)m_pCache.GetNext( pos );
}


//////////////////////////////////////////////////////////////////////
// CPongItem construction

CPongItem::CPongItem(CNeighbour* pNeighbour, IN_ADDR* pAddress, WORD nPort, BYTE nHops, DWORD nFiles, DWORD nVolume)
{
	m_pNeighbour	= pNeighbour;
	m_pAddress		= *pAddress;
	m_nPort			= nPort;
	m_nHops			= nHops;
	m_nFiles		= nFiles;
	m_nVolume		= nVolume;
}

CPongItem::~CPongItem()
{
}

//////////////////////////////////////////////////////////////////////
// CPongItem packet conversion

CG1Packet* CPongItem::ToPacket(int nTTL, GGUID* pGUID)
{
	CG1Packet* pPong = CG1Packet::New( G1_PACKET_PONG, nTTL, pGUID );

	pPong->m_nHops = m_nHops;

	pPong->WriteShortLE( m_nPort );
	pPong->WriteLongLE( *(DWORD*)&m_pAddress );
	pPong->WriteLongLE( m_nFiles );
	pPong->WriteLongLE( m_nVolume );

	return pPong;
}