QT 线程池 + TCP 小试（二）实现通信功能



*免分资源链接点击打开链接http://download.csdn.net/detail/goldenhawking/4492378

        有了线程池，我们下一步就利用 QTcpServer 搭建一个服务器，接受客户端的连接，并把数据发送到线程池上。由于 QTcpServer 资料太多了，这里不在赘述。唯一值得注意的是，当客户端退出时，如果线程池队列中还有该客户的信息，这个信息还会被处理，只是无法再发送回去而已。其实，还可实现成客户端退出，就发一个信号到线程池，删除自己的所有任务。这个也很简单，但之所以没有做，因为这些数据的处理结果可能还会被其他消费者（而非生产者自己）使用，最典型的例子是从工业传感器上采集的数据，其生成的图像需要存储到设备中去。

       QTcpSocket的 Write 方法默认是支持大体积数据的，即使一次发了500MB的数据，只要硬件资源可以承受，调用也会成功并立刻返回。接受者会以一定的载荷大小不停的触发readyRead，直到发送全部成功。但是，为了能够观察到并控制收发队列中的数据包的大小、体积，我们在外层实现了一个发送队列，每次以 payLoad为大小发送数据包。这是从MFC中带来的习惯，很难说好坏。

 qghtcpserver.h

#ifndef QGHTCPSERVER_H #define QGHTCPSERVER_H#include <QTcpServer> #include <QMap> #include <QList>class QGHTcpServer : public QTcpServer {Q_OBJECTpublic:QGHTcpServer(QObject *parent,int nPayLoad = 4096);~QGHTcpServer();//踢出所有客户void KickAllClients();QList <QObject *> clientsList();void SetPayload(int nPayload); private:QMap<QObject *,QList<QByteArray> > m_buffer_sending;QMap<QObject *,QList<qint64> > m_buffer_sending_offset;QMap<QObject*,int> m_clientList;int m_nPayLoad; public slots://新的客户连接到来void new_client_recieved();//客户连接被关闭void client_closed();//新的数据到来void new_data_recieved();//一批数据发送完毕void some_data_sended(qint64);//客户端错误void displayError(QAbstractSocket::SocketError socketError);//向客户端发送数据void SendDataToClient(QObject * objClient,const QByteArray & dtarray);//向客户端广播数据，不包括 objFromClientvoid BroadcastData(QObject * objFromClient,const QByteArray & dtarray); signals://错误信息void evt_SocketError(QObject * senderSock ,QAbstractSocket::SocketError socketError);//新的客户端连接void evt_NewClientConnected(QObject * client);//客户端退出void evt_ClientDisconnected(QObject * client);//收到一批数据void evt_Data_recieved(QObject * ,const QByteArray & );//一批数据被发送void evt_Data_transferred(QObject * client,qint64); };#endif // QGHTCPSERVER_H
qghtcpserver.cpp

#include "qghtcpserver.h" #include <assert.h> #include <QTcpSocket> QGHTcpServer::QGHTcpServer(QObject *parent,int nPayLoad ): QTcpServer(parent),m_nPayLoad(nPayLoad) {assert(m_nPayLoad>=256 && m_nPayLoad<=16*1024*1024);connect(this, SIGNAL(newConnection()), this, SLOT(new_client_recieved())); }QGHTcpServer::~QGHTcpServer() {} QList <QObject *> QGHTcpServer::clientsList() {return m_clientList.keys(); } void QGHTcpServer::SetPayload(int nPayload) {m_nPayLoad = nPayload;assert(m_nPayLoad>=256 && m_nPayLoad<=16*1024*1024); }void QGHTcpServer::new_client_recieved() {QTcpSocket * sock_client = nextPendingConnection();while (sock_client){connect(sock_client, SIGNAL(readyRead()),this, SLOT(new_data_recieved()));connect(sock_client, SIGNAL(disconnected()),this,SLOT(client_closed()));connect(sock_client, SIGNAL(error(QAbstractSocket::SocketError)),this, SLOT(displayError(QAbstractSocket::SocketError)));connect(sock_client, SIGNAL(bytesWritten(qint64)), this, SLOT(some_data_sended(qint64)));m_clientList[sock_client] = 0;emit evt_NewClientConnected(sock_client);sock_client = nextPendingConnection();} } void QGHTcpServer::client_closed() {QTcpSocket * pSock = qobject_cast<QTcpSocket*>(sender());if (pSock){emit evt_ClientDisconnected(pSock);m_buffer_sending.remove(pSock);m_buffer_sending_offset.remove(pSock);m_clientList.remove(pSock);pSock->deleteLater();} } void QGHTcpServer::new_data_recieved() {QTcpSocket * pSock = qobject_cast<QTcpSocket*>(sender());if (pSock)emit evt_Data_recieved(pSock,pSock->readAll()); } void QGHTcpServer::some_data_sended(qint64 wsended) {QTcpSocket * pSock = qobject_cast<QTcpSocket*>(sender());if (pSock){emit evt_Data_transferred(pSock,wsended);QList<QByteArray> & list_sock_data = m_buffer_sending[pSock];QList<qint64> & list_offset = m_buffer_sending_offset[pSock];while (list_sock_data.empty()==false){QByteArray & arraySending = *list_sock_data.begin();qint64 & currentOffset = *list_offset.begin();qint64 nTotalBytes = arraySending.size();assert(nTotalBytes>=currentOffset);qint64 nBytesWritten = pSock->write(arraySending.constData()+currentOffset,qMin((int)(nTotalBytes-currentOffset),m_nPayLoad));currentOffset += nBytesWritten;if (currentOffset>=nTotalBytes){list_offset.pop_front();list_sock_data.pop_front();}elsebreak;}} } void QGHTcpServer::displayError(QAbstractSocket::SocketError socketError) {QTcpSocket * pSock = qobject_cast<QTcpSocket*>(sender());if (pSock){emit evt_SocketError(pSock,socketError);pSock->disconnectFromHost();} }void QGHTcpServer::SendDataToClient(QObject * objClient,const QByteArray & dtarray) {if (m_clientList.find(objClient)==m_clientList.end())return;QTcpSocket * pSock = qobject_cast<QTcpSocket*>(objClient);if (pSock&&dtarray.size()){QList<QByteArray> & list_sock_data = m_buffer_sending[pSock];QList<qint64> & list_offset = m_buffer_sending_offset[pSock];if (list_sock_data.empty()==true){qint64 bytesWritten = pSock->write(dtarray.constData(),qMin(dtarray.size(),m_nPayLoad));if (bytesWritten < dtarray.size()){list_sock_data.push_back(dtarray);list_offset.push_back(bytesWritten);}}else{list_sock_data.push_back(dtarray);list_offset.push_back(0);} } } void QGHTcpServer::BroadcastData(QObject * objClient,const QByteArray & dtarray) {for(QMap<QObject *,int>::iterator p = m_clientList.begin();p!=m_clientList.end();p++){QTcpSocket * pSock = qobject_cast<QTcpSocket*>(p.key());if (pSock&&dtarray.size()&&pSock!=objClient){QList<QByteArray> & list_sock_data = m_buffer_sending[pSock];QList<qint64> & list_offset = m_buffer_sending_offset[pSock];if (list_sock_data.empty()==true){qint64 bytesWritten = pSock->write(dtarray.constData(),qMin(dtarray.size(),m_nPayLoad));if (bytesWritten < dtarray.size()){list_sock_data.push_back(dtarray);list_offset.push_back(bytesWritten);}else{list_sock_data.push_back(dtarray);list_offset.push_back(0);} }} } } void QGHTcpServer::KickAllClients() {QList<QObject *> clientList = m_clientList.keys();foreach(QObject * obj,clientList){QTcpSocket * pSock = qobject_cast<QTcpSocket*>(obj);if (pSock){pSock->disconnectFromHost();} }} 下一次，我会介绍最后的实现功能。

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