基于UDP的IOCP在接收数据操作时 如何区分数据

Question

本帖最后由 stolen007 于 2011-05-29 06:43:39 编辑

Answer 1

那请问是否会影响效率呢  能否给个具体代码 我加入CRC校验  
还有 客户端把封包分成100个 万一丢包呢 我要怎么组合 比较有效率

Answer 2

我自己的实现代码 但是还没有全部完成 大家帮我看看
GENERAL_CONTEXT *pGeneralContext=pUdpContext->pGenContext;
if (pGeneralContext->CrcSize!=crc16((uint8 *)pGeneralContext->buff,sizeof(pGeneralContext->buff)))
{
//要求重新发送 设置一个重新发送的标志 
}
else
{
if(pGeneralContext->TotalNO>0) //判断是否是只有一个 只有一个就不用下面这些操作了
{
         for ()//循环查找链表
         {
 if (pGeneralContext->Flag=) //循环比较
 {
 //继续插入 要加入10个字节的偏移  判断是否完整
 if ()
 {
                     
 }
 }

         }
}

/*否则就是 没有发送错误的 首先判断是否是多个封包pGeneralContext->TotalNO
判断是否是最新编码  迭代比较pGeneralContext->Flag 如果找不到就新建一个指针保存   
如果不是就插入到 指定标志的偏移里 判断是否完整了 如果完整则传递给客户 释放掉数据
*/

Answer 3

int CIocpServer::IssueUdpSendOp(struct sockaddr_in& remoteAddr,char* buf,unsigned long data_len,SOCKET socket,char * Flag)
{
try
{
if(m_bStopServer) 
{
return FALSE;
} if(m_pUdpContextManager==NULL)
throw CSrvException("IssueUdpSendOp m_pUdpContextManager指针非法.",-1); //下面的循环是把数据块分包
unsigned long leave_bytes = data_len;
unsigned long trans_bytes = data_len;
unsigned short counter = 0;
// unsigned short data_start_index = 0;  //数据真实的起始位
           GENERAL_CONTEXT *pGeneralContext;
   memset((char *)pGeneralContext,0,sizeof(pGeneralContext));
   if (data_len>DEFAULT_UDP_BUFFER_SIZE)
   {
   if ((data_len%DEFAULT_UDP_BUFFER_SIZE)==0)
   {
   pGeneralContext->TotalNO=(data_len/DEFAULT_UDP_BUFFER_SIZE);
   }
   else
   {
                       pGeneralContext->TotalNO=(data_len/DEFAULT_UDP_BUFFER_SIZE)+1;
   }
           
   }
   else
   {
   pGeneralContext->TotalNO=0;
   }
   memcpy(pGeneralContext->Flag,Flag,sizeof(Flag));

do
{
 memset((char *)pGeneralContext->buff,0,sizeof(pGeneralContext->buff));
           memset((char *)pGeneralContext->CrcSize,0,sizeof(pGeneralContext->CrcSize));
    memset((char *)pGeneralContext->SortNo,0,sizeof(pGeneralContext->SortNo));
UDP_CONTEXT* pUdpContext = NULL;
m_pUdpContextManager->GetContext(pUdpContext);

if(pUdpContext==NULL)
throw CSrvException("pUdpContext指针非法.",-1); if(leave_bytes <=DEFAULT_UDP_BUFFER_SIZE) //小于一次发送量
trans_bytes = leave_bytes;
else
trans_bytes = DEFAULT_UDP_BUFFER_SIZE;

leave_bytes = leave_bytes - trans_bytes; //一次发送后剩余的字节数

// memcpy(pUdpContext->data_buffer,buf+counter*DEFAULT_UDP_BUFFER_SIZE,trans_bytes);  //拷贝字节数
             memcpy(pGeneralContext->buff,buf+counter*DEFAULT_UDP_BUFFER_SIZE,trans_bytes);  //拷贝字节数
 pGeneralContext->CrcSize=crc16((uint8 *)pGeneralContext->buff,sizeof(pGeneralContext->buff));
counter++;
                pGeneralContext->SortNo=counter;
ZeroMemory(&pUdpContext->operate_overlapped,sizeof(WSAOVERLAPPED));
pUdpContext->operate_type = IO_UDP_SEND;
pUdpContext->socket = socket;
pUdpContext->operate_buffer.buf =(char *) pUdpContext->pGenContext;
pUdpContext->operate_buffer.len = trans_bytes;//注意此处的6
pUdpContext->remote_address = remoteAddr;
pUdpContext->remote_address_len = sizeof(struct sockaddr);

DWORD nubmerBytes = 0;
int err = WSASendTo(
pUdpContext->socket,
&pUdpContext->operate_buffer,
1,
&nubmerBytes,
0,
(struct sockaddr*)&pUdpContext->remote_address,
sizeof(pUdpContext->remote_address),
&pUdpContext->operate_overlapped,
NULL);
if(SOCKET_ERROR == err && WSA_IO_PENDING != WSAGetLastError())
{
ReleaseContext((IO_PER_HANDLE_STRUCT*)pUdpContext);
throw CSrvException("IssueUdpSendOp->WSASend发生错误.",WSAGetLastError());
}
else if(0 == err)
{
//还要考虑立即完成的情况
}

}while(leave_bytes>0); return TRUE;
}
catch(CSrvException& e)
{
this->PrintDebugMessage(e);
if(m_bExceptionStop)
throw e;
}
catch(...)
{
string message("IssueUdpSendOp 发生未知异常.");
PrintDebugMessage(message.c_str());
if(m_bExceptionStop)
throw message;
}
return FALSE;
}