#include "StdAfx.h"
#include "NetServer.h"
#include "NetClient.h"
#include "NetLinkMain.h"


CNetServer::CNetServer(CNetLinkMain* pParent) : CSocketBase(pParent), m_lpfnAcceptEx(NULL), m_lpfnGetAcceptExSockAddrs(NULL)
{
}


CNetServer::~CNetServer(void)
{
	// 释放掉所有的IO上下文数据
	for( int i = 0; i < m_ArrayIoContext.GetCount(); ++i)
	{
		delete m_ArrayIoContext.GetAt(i);
	}
	m_ArrayIoContext.RemoveAll();
}

/*****************************************************************
**【函数名称】	__newIoContext
**【函数功能】	创建IoContext用于接收客户端连接
**【参数】		
**【返回值】
****************************************************************/
CNetServer::PPER_IO_CONTEXT CNetServer::__newIoContext( void )
{
	PPER_IO_CONTEXT pContext = new PER_IO_CONTEXT;
	ASSERT(pContext != NULL);

	m_ArrayIoContext.Add( pContext );

	return pContext;
}

/*****************************************************************
**【函数名称】	__deleteIoContext
**【函数功能】	删除废弃的IoContext
**【参数】		
**【返回值】
****************************************************************/
void CNetServer::__deleteIoContext( PPER_IO_CONTEXT pIoContext )
{
	ASSERT( pIoContext != NULL );

	for( int i=0; i<m_ArrayIoContext.GetCount(); ++i )
	{
		if( pIoContext == m_ArrayIoContext.GetAt(i) )
		{
			m_ArrayIoContext.RemoveAt(i);
			delete pIoContext;
			pIoContext = NULL;		
			break;
		}
	}
}

/*****************************************************************
**【函数名称】	__postAccept
**【函数功能】	投递Accept请求
**【参数】		
**【返回值】
****************************************************************/
bool CNetServer::__postAccept( PPER_IO_CONTEXT pIoContext )
{
	ASSERT( INVALID_SOCKET != m_Socket );

	// 准备参数
	DWORD dwBytes = 0;
	pIoContext->resetBuffer();
	WSABUF *pWsaBuf = &pIoContext->m_wsaBuf;
	OVERLAPPED *pOl = &pIoContext->m_Overlapped;

	// 为以后新连入的客户端先准备好Socket( 这个是与传统accept最大的区别 ) 
	pIoContext->m_sockAccept  = WSASocket(AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, 0, WSA_FLAG_OVERLAPPED);  
	if( INVALID_SOCKET == pIoContext->m_sockAccept )  
		return false;

	// 投递AcceptEx
	if(FALSE == m_lpfnAcceptEx(m_Socket, pIoContext->m_sockAccept, pWsaBuf->buf, 0,	sizeof(SOCKADDR_IN) + 16, sizeof(SOCKADDR_IN) + 16, &dwBytes, pOl))  
	{  
		if(WSA_IO_PENDING != WSAGetLastError())
			return false;
	} 

	return true;
}

/*****************************************************************
**【函数名称】	doJob
**【函数功能】	开始创建客户端并投递Accept请求
**【参数】		
**【返回值】
****************************************************************/
void CNetServer::doJob( OVERLAPPED* pOverLapped, DWORD BytesTransfered )
{
	ASSERT(pOverLapped != NULL);

	SOCKADDR_IN* ClientAddr = NULL;
	SOCKADDR_IN* LocalAddr = NULL;
	int remoteLen = sizeof(SOCKADDR_IN), localLen = sizeof(SOCKADDR_IN);
	PER_IO_CONTEXT* pIoContext = CONTAINING_RECORD(pOverLapped, PER_IO_CONTEXT, m_Overlapped);
	ASSERT(pIoContext != NULL);

	// 1. 首先取得连入客户端的地址信息
	m_lpfnGetAcceptExSockAddrs(pIoContext->m_wsaBuf.buf, 0, sizeof(SOCKADDR_IN) + 16, sizeof(SOCKADDR_IN) + 16, 
		(LPSOCKADDR*)&LocalAddr, &localLen, (LPSOCKADDR*)&ClientAddr, &remoteLen);

	// 2. 创建客户端
	CNetClient* pClient = new CNetClient(m_pParent, PDU_LINK_TYPE_SERVER, false);
	ASSERT(pClient != NULL);
	pClient->assoSocket() = pIoContext->m_sockAccept;
	pClient->setFarLinkInfo(inet_ntoa(ClientAddr->sin_addr), ntohs(ClientAddr->sin_port));

	// 3. 使用完毕之后，投递新的AcceptEx
	__postAccept( pIoContext );

	// 4. 通知上层新客户端到来
	m_pParent->onConnEstablished(pClient);	
}

/*****************************************************************
**【函数名称】	create
**【函数功能】	创建
**【参数】		
**【返回值】
****************************************************************/
bool CNetServer::create( int a_ListenPort )
{
	m_Socket = WSASocket(AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, 0, WSA_FLAG_OVERLAPPED);
	if (INVALID_SOCKET == m_Socket) 
		return false;

	// 将Listen Socket绑定至完成端口中
	if(!m_pParent->waitNetEnd(this))
		return false;

	struct sockaddr_in ServerAddress;
	// 填充地址信息
	ZeroMemory(&ServerAddress, sizeof(ServerAddress));
	ServerAddress.sin_family = AF_INET;
	ServerAddress.sin_addr.s_addr = htonl(INADDR_ANY);                           
	ServerAddress.sin_port = htons(a_ListenPort);                          

	// 绑定地址和端口
	if (SOCKET_ERROR == bind(m_Socket, (struct sockaddr *) &ServerAddress, sizeof(ServerAddress))) 
		return false;

	// 开始进行监听
	if (SOCKET_ERROR == listen(m_Socket, SOMAXCONN))
		return false;

	// 使用AcceptEx函数，因为这个是属于WinSock2规范之外的微软另外提供的扩展函数
	// 所以需要额外获取一下函数的指针
	GUID GuidAcceptEx = WSAID_ACCEPTEX;  
	GUID GuidGetAcceptExSockAddrs = WSAID_GETACCEPTEXSOCKADDRS; 
	DWORD dwBytes = 0;
	if(SOCKET_ERROR == WSAIoctl(m_Socket, SIO_GET_EXTENSION_FUNCTION_POINTER, &GuidAcceptEx, sizeof(GuidAcceptEx), 
		&m_lpfnAcceptEx, sizeof(m_lpfnAcceptEx), &dwBytes, NULL, NULL))  
	{  
		return false;  
	}

	// 获取GetAcceptExSockAddrs函数指针，也是同理
	if(SOCKET_ERROR == WSAIoctl(m_Socket, SIO_GET_EXTENSION_FUNCTION_POINTER, &GuidGetAcceptExSockAddrs, sizeof(GuidGetAcceptExSockAddrs), 
		&m_lpfnGetAcceptExSockAddrs, sizeof(m_lpfnGetAcceptExSockAddrs),  &dwBytes, NULL, NULL))  
	{
		return false; 
	}

	// 为AcceptEx 准备参数，然后投递AcceptEx I/O请求
	for( int i = 0; i < MAX_POST_ACCEPT; ++i )
	{
		PER_IO_CONTEXT* pAcceptIoContext = __newIoContext();

		if(!__postAccept(pAcceptIoContext))
		{
			__deleteIoContext(pAcceptIoContext);
			return false;
		}
	}

	return true;
}