eva0.4.1源码看看4

/***************************************************************************
 *   Copyright (C) 2004 by yunfan                                          *
 *   yunfan_zg@163.com                                                     *
 *                                                                         *
 *   This program 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.                                   *
 *                                                                         *
 *   This program 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 this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#ifndef EVASERVERS_H
#define EVASERVERS_H
#include <qobject.h>
#include <qvaluelist.h> //qt这么多奇怪的list
#include <qhostaddress.h>
/**
This class loads all Tencent's tcp and udp servers, and return a random server IP address
This class also involves some DNS operations.
看样子，是直接用qq的服务器，他从哪里知道的qq的服务器，还能有dns操作。未接触的知识
@author yunfan
*/
class QDns;
class EvaServers : public QObject
{
    Q_OBJECT
public:
    EvaServers(QString &dataRoot);
               
    virtual ~EvaServers();
    void fetchAddress(bool isUdp);
signals:
    void isReady(QHostAddress ip);
private:
    typedef struct serverItem{
        int type;  
        QString addr;
    } serverItem;
               
    enum { UDP, TCP, Addr_URL, Addr_IP};
               
    QString filename;
    bool gotIP;
    bool isLoaded;
    int fetchType;
    QDns *dns; //qt还有dns类。无所不能
    QValueList<serverItem> TCPServers;
    QValueList<serverItem> UDPServers;
               
    bool loadServers();
    void defaultAddress();
private slots:
    void getResultsSlot();
};
#endif

/***************************************************************************
 *   Copyright (C) 2004 by yunfan                                          *
 *   yunfan_zg@163.com                                                     *
 *                                                                         *
 *   This program 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.                                   *
 *                                                                         *
 *   This program 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 this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#include "evaservers.h"
#include <qdns.h>
#include <qfile.h>
#include <qdatastream.h>
#include <qdatetime.h>   // seed for rand()
#include <stdlib.h>      // rand() function
EvaServers::EvaServers(QString &dataRoot):
    gotIP(FALSE),
    isLoaded(FALSE)
{
    filename = dataRoot + "/servers";
    QTime t = QTime::currentTime();
    srand( t.hour()*12+t.minute()*60+t.second()*60 );
    isLoaded = this->loadServers();
    dns = NULL;
}
EvaServers::~EvaServers()
{
    delete dns;
}
void EvaServers::fetchAddress( bool isUdp )
{
    int num = 0;
    if(isUdp){
      num = UDPServers.count();
      fetchType = UDP;
    } else{
      num = TCPServers.count();
      fetchType = TCP;
    }
    if(num == 0 ){
        defaultAddress();
        return;
    }
    int index = rand() % num;
    serverItem addr;
    if(isUdp)
      addr = UDPServers[index];
    else
      addr = TCPServers[index];
       
    if(addr.type == Addr_IP){
        emit isReady(QHostAddress(addr.addr.latin1())); // this way, Red hat 9 might work properly
        return;
    }
     
    // the address should be a URL now, so we try to get the IP         
    if(dns!=NULL) {
        QObject::disconnect(dns, 0,0,0);
        delete dns;
    }
    dns =  new QDns(addr.addr, QDns::A);   
    QObject::connect(dns, SIGNAL(resultsReady()), this, SLOT(getResultsSlot()));
}
bool EvaServers::loadServers( )
{
    QFile file(filename);   
    if(!file.open(IO_ReadOnly)){
            return FALSE;
    }
       
    QTextStream stream(&file);
    QString line;
    QStringList lineList;
    int nextType = 0;
    while(!stream.atEnd()){
        line = stream.readLine().stripWhiteSpace();
        if(line == "UDP"){
            nextType = UDP;
            continue;
        }else if(line == "TCP"){
            nextType = TCP;
            continue;
        } else if(line == "" ){
            //nextType = 0;
            continue;
            }
                   
        lineList = QStringList::split(":", line);
       
        if(lineList.size() != 2)
          continue;
        lineList[0].stripWhiteSpace();
                           
        serverItem *item = new serverItem();   
        if(lineList[0]=="URL"){       
            item->type = Addr_URL;               
        }else if(lineList[0]=="IP"){
            item->type = Addr_IP;
        }else
            continue;
           
        item->addr = lineList[1].stripWhiteSpace();
           
        if(nextType == UDP){
            UDPServers.append(*item);//从file里面获得server地址列表
        }
           
        if(nextType == TCP){
            TCPServers.append(*item);
        }
    }
       
    file.close();
    return TRUE; 
}
void EvaServers::defaultAddress()
{   
    if(fetchType == TCP){
        emit isReady(QHostAddress("218.17.209.23")); //这个是缺省地址。
    }else{
        emit isReady(QHostAddress("218.17.209.20")); //又是tcp又是udp，腾讯真正的是怎么个逻辑通信的？ 
    }   
}
void EvaServers::getResultsSlot( )
{
    QValueList<QHostAddress> list = dns->addresses();//域名解析出来ip地址
    if(list.count() == 0 ){
        defaultAddress();
        return;
    }
       
    QHostAddress addr = list[0];
    emit isReady(addr);
}

管中窥豹啊。