std::string GCGV_ReqGetNodes::OnRequest(const char* JSON) {
SetupRequest(JSON);
FindNodes();
BuildReply();
return reply.GetAndClear();
}
/*!
\brief 事件由ServiceSession Task进行处理，大多数为网络报文处理事件
\param
\return 处理完成返回0,断开Session返回-1
\ingroup
\see
*/
SInt64 CServiceSession::Run()
{
//获取事件类型
EventFlags events = this->GetEvents();
QTSS_Error err = QTSS_NoErr;
QTSSModule* theModule = NULL;
UInt32 numModules = 0;
// Some callbacks look for this struct in the thread object
OSThreadDataSetter theSetter(&fModuleState, NULL);
//超时事件或者Kill事件，进入释放流程：清理 & 返回-1
if (events & Task::kKillEvent)
fLiveSession = false;
if(events & Task::kTimeoutEvent)
{
//客户端Session超时，暂时不处理
char msgStr[512];
qtss_snprintf(msgStr, sizeof(msgStr), "session timeout,release session\n");
QTSServerInterface::LogError(qtssMessageVerbosity, msgStr);
return -1;
}
//正常事件处理流程
while (this->IsLiveSession())
{
//报文处理以状态机的形式，可以方便多次处理同一个消息
switch (fState)
{
case kReadingFirstRequest://首次对Socket进行读取
{
if ((err = fInputStream.ReadRequest()) == QTSS_NoErr)
{
//如果RequestStream返回QTSS_NoErr，就表示已经读取了目前所到达的网络数据
//但，还不能构成一个整体报文，还要继续等待读取...
fInputSocketP->RequestEvent(EV_RE);
return 0;
}
if ((err != QTSS_RequestArrived) && (err != E2BIG))
{
// Any other error implies that the client has gone away. At this point,
// we can't have 2 sockets, so we don't need to do the "half closed" check
// we do below
Assert(err > 0);
Assert(!this->IsLiveSession());
break;
}
if ((err == QTSS_RequestArrived) || (err == E2BIG))
fState = kHaveCompleteMessage;
}
continue;
case kReadingRequest://读取请求报文
{
//读取锁，已经在处理一个报文包时，不进行新网络报文的读取和处理
OSMutexLocker readMutexLocker(&fReadMutex);
//网络请求报文存储在fInputStream中
if ((err = fInputStream.ReadRequest()) == QTSS_NoErr)
{
//如果RequestStream返回QTSS_NoErr，就表示已经读取了目前所到达的网络数据
//但，还不能构成一个整体报文，还要继续等待读取...
fInputSocketP->RequestEvent(EV_RE);
return 0;
}
if ((err != QTSS_RequestArrived) && (err != E2BIG) && (err != QTSS_BadArgument))
{
//Any other error implies that the input connection has gone away.
// We should only kill the whole session if we aren't doing HTTP.
// (If we are doing HTTP, the POST connection can go away)
Assert(err > 0);
if (fOutputSocketP->IsConnected())
{
// If we've gotten here, this must be an HTTP session with
// a dead input connection. If that's the case, we should
// clean up immediately so as to not have an open socket
// needlessly lingering around, taking up space.
Assert(fOutputSocketP != fInputSocketP);
Assert(!fInputSocketP->IsConnected());
fInputSocketP->Cleanup();
return 0;
}
else
{
Assert(!this->IsLiveSession());
break;
}
}
fState = kHaveCompleteMessage;
}
case kHaveCompleteMessage://读取到完整的请求报文
{
Assert( fInputStream.GetRequestBuffer() );
Assert(fRequest == NULL);
//根据具体请求报文构造HTTPRequest请求类
fRequest = NEW HTTPRequest(&sServiceStr, fInputStream.GetRequestBuffer());
//在这里，我们已经读取了一个完整的Request，并准备进行请求的处理，直到响应报文发出
//在此过程中，此Session的Socket不进行任何网络数据的读/写；
fReadMutex.Lock();
fSessionMutex.Lock();
//清空发送缓冲区
fOutputStream.ResetBytesWritten();
//网络请求超过了缓冲区，返回Bad Request
if (err == E2BIG)
{
//返回HTTP报文，错误码408
//(void)QTSSModuleUtils::SendErrorResponse(fRequest, qtssClientBadRequest, qtssMsgRequestTooLong);
fState = kSendingResponse;
break;
}
// Check for a corrupt base64 error, return an error
if (err == QTSS_BadArgument)
{
//返回HTTP报文，错误码408
//(void)QTSSModuleUtils::SendErrorResponse(fRequest, qtssClientBadRequest, qtssMsgBadBase64);
fState = kSendingResponse;
break;
}
Assert(err == QTSS_RequestArrived);
fState = kFilteringRequest;
}
case kFilteringRequest:
{
//刷新Session保活时间
fTimeoutTask.RefreshTimeout();
//对请求报文进行解析
QTSS_Error theErr = SetupRequest();
//当SetupRequest步骤未读取到完整的网络报文，需要进行等待
if(theErr == QTSS_WouldBlock)
{
this->ForceSameThread();
fInputSocketP->RequestEvent(EV_RE);
// We are holding mutexes, so we need to force
// the same thread to be used for next Run()
return 0;//返回0表示有事件才进行通知，返回>0表示规定事件后调用Run
}
//每一步都检测响应报文是否已完成，完成则直接进行回复响应
if (/*fRequest->HasResponseBeenSent()*/fOutputStream.GetBytesWritten() > 0)
{
fState = kSendingResponse;
break;
}
fState = kPreprocessingRequest;
break;
}
case kPreprocessingRequest:
{
//请求预处理过程
//TODO:报文处理过程
fState = kCleaningUp;
break;
}
case kProcessingRequest:
{
if (fOutputStream.GetBytesWritten() == 0)
{
//如果到这里，响应报文还没有形成，返回500 Server Internal Error
////QTSSModuleUtils::SendErrorResponse(fRequest, qtssServerInternal, qtssMsgNoModuleForRequest);
}
fState = kSendingResponse;
}
case kSendingResponse:
{
//响应报文发送，确保完全发送
Assert(fRequest != NULL);
//发送响应报文
err = fOutputStream.Flush();
if (err == EAGAIN)
{
// If we get this error, we are currently flow-controlled and should
// wait for the socket to become writeable again
//如果收到Socket EAGAIN错误，那么我们需要等Socket再次可写的时候再调用发送
fSocket.RequestEvent(EV_WR);
this->ForceSameThread();
// We are holding mutexes, so we need to force
// the same thread to be used for next Run()
return 0;
}
else if (err != QTSS_NoErr)
{
// Any other error means that the client has disconnected, right?
Assert(!this->IsLiveSession());
break;
}
fState = kCleaningUp;
}
case kCleaningUp:
{
// Cleaning up consists of making sure we've read all the incoming Request Body
// data off of the socket
if (this->GetRemainingReqBodyLen() > 0)
{
err = this->DumpRequestData();
if (err == EAGAIN)
{
fInputSocketP->RequestEvent(EV_RE);
this->ForceSameThread(); // We are holding mutexes, so we need to force
// the same thread to be used for next Run()
return 0;
}
}
//一次请求的读取、处理、响应过程完整，等待下一次网络报文！
this->CleanupRequest();
fState = kReadingRequest;
}
}
}
//清空Session占用的所有资源
this->CleanupRequest();
//Session引用数为0，返回-1后，系统会将此Session删除
if (fObjectHolders == 0)
return -1;
//如果流程走到这里，Session实际已经无效了，应该被删除，但没有，因为还有其他地方引用了Session对象
return 0;
}
