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用DELPHI设计代理服务器程序(前面一贴,没贴好,请原谅)
作者:武汉SEO闵涛  文章来源:敏韬网  点击数1923  更新时间:2009/4/23 18:44:19  文章录入:mintao  责任编辑:mintao
      end;
        end
        else
        begin
          host:=trim(line);{获取主机地址}
          port:=80;
        end;
        if not session[i-1].remote_connected then{假如远征尚未连接}
        begin
          session[i-1].Request:=true;{置请求数据就绪标志}
          session[i-1].CSocket.host:=host;{设置远程主机地址}
          session[i-1].CSocket.port:=port;{设置端口}
          session[i-1].CSocket.active:=true;{连接远程主机}
          session[i-1].Lookingup:=true;{置标志}
          session[i-1].LookupTime:=0;{从0开始计时}
        end
        else
       {假如远程已连接,直接发送请求}
          session[i-1].CSocket.socket.sendtext(session[i-1].request_str);
        break;{停止扫描请求文本}
      end;
      j:=pos(char(13)+char(10),tmp);{指向下一行}
    end;
    break;{停止循环}   
end;
//当连接远程主机成功时
procedure TForm1.ClientSocket1Connect(Sender: TObject;Socket: TCustomWinSocket);
var i: integer;
begin
  for i:=1 to sessions do
    if (session[i-1].CSocket.socket.sockethandle= socket.SocketHandle)and session[i-1].Used < BR>     then
    begin
      session[i-1].CSocket.tag:=socket.SocketHandle;
      session[i-1].remote_connected:=true;{置远程主机已连通标志}
      session[i-1].Lookingup:=false;{清标志}
      break;
    end;
end;
//当远程主机断开时
procedure TForm1.ClientSocket1Disconnect(Sender: TObject; Socket: TCustomWinSocket);
var i,j,k: integer;
begin
 for i:=1 to sessions do
  if (session[i-1].CSocket.tag=socket.SocketHandle) and session[i-1].Used then
  begin
    session[i-1].remote_connected:=false;{置为未连接}
    if not session[i-1].client_connected then
       session[i-1].Used:=false{假如客户机已断开,则置释放资源标志}
    else for k:=1 to serversocket1.Socket.ActiveConnections do
       if (serversocket1.Socket.Connections[k-1].SocketHandle=session[i-1].SS_Handle) and
       session[i-1].used then
       begin
         serversocket1.Socket.Connections[k-1].Close;
         break;
       end;
    break;
  end;
  j:=sessions;
  k:=0;
  for i:= 1 to j do
  begin
    if session[j-i].Used then break;
    inc(k);
  end;
  if k>0 then{修正会话数组}
  begin
    sessions:=sessions-k;
    setlength(session,sessions);
  end;
  edit1.text:=inttostr(sessions);
end;
file://当与远程主机通信发生错误时/
procedure TForm1.ClientSocket1Error(Sender: TObject; Socket: TCustomWinSocket; ErrorEvent: TErrorEvent; var ErrorCode: Integer);
var i,j,k: integer;
begin
  for i:=1 to sessions do
    if (session[i-1].CSocket.tag=socket.SocketHandle) and session[i-1].Used then
    begin
      socket.close;
      session[i-1].remote_connected:=false;{置为未连接}
      if not session[i-1].client_connected then
         session[i-1].Used:= false{假如客户机已断开,则置释放资源标志}
      else
         for k:=1 to serversocket1.Socket.ActiveConnections do
           if (serversocket1.Socket.Connections[k-1].SocketHandle=session[i-1].SS_Handle)
           and session[i-1].used then
           begin
             serversocket1.Socket.Connections[k-1].Close;
             break;
           end;
         break;
    end;
    j:= sessions;
    k:= 0;
    for i:= 1 to j do
    begin
      if session[j-i].Used then break;
      inc(k);
    end;
    errorcode:= 0;
    if k>0 then{修正会话数组}
    begin
      sessions:=sessions-k;
      setlength(session,sessions);
    end;
    edit1.text:= inttostr(sessions);
end;
//向远程主机发送页面请求
procedure TForm1.ClientSocket1Write(Sender: TObject; Socket:TCustomWinSocket);
var i: integer;
begin
  for i:= 1 to sessions do
    if (session[i-1].CSocket.tag= socket.SocketHandle) and session[i-1].Used then
    begin
      if session[i-1].Request then
      begin
        socket.SendText(session[i-1].request_str);{假如有请求,发送}
        session[i-1].Request:= false;{清标志}
      end;
      break;
    end;
end;
//远程主机发来页面数据时
procedure TForm1.ClientSocket1Read(Sender: TObject;Socket: TCustomWinSocket);
var i,j: integer;
    rec_bytes: integer;{传回的数据块长度}
    rec_Buffer: array[0..2047] of char; {传回的数据块缓冲区}
begin
  for i:= 1 to sessions do
    if (session[i-1].CSocket.tag= socket.SocketHandle) and session[i-1].Used then
    begin
      rec_bytes:= socket.ReceiveBuf(rec_buffer,2048); {接收数据}
      for j:= 1 to serversocket1.Socket.ActiveConnections do
        if serversocket1.Socket.Connections[j-1].SocketHandle= session[i-1].SS_Handle then
        begin
          serversocket1.Socket.Connections[j-1].SendBuf(rec_buffer,rec_bytes); {发送数据}
          break;
        end;
      break;
    end;
end;
//“页面找不到”等错误信息出现时
procedure TForm1.AppException(Sender:TObject; E: Exception);
begin
  inc(invalidrequests);
end;
file://查找远程主机定时/
procedure TForm1.Timer1Timer(Sender: TObject);
var i,j: integer;
begin
  for i:= 1 to sessions do
    if session[i-1].Used and session[i-1].Lookingup then{假如正在连接}
    begin
      inc(session[i-1].LookupTime);
      if session[i-1].LookupTime > lookuptimeout then{假如超时}
      begin
        session[i-1].Lookingup:=false;
        session[i-1].CSocket.active:=false;{停止查找}
        for j:=1 to serversocket1.Socket.ActiveConnections do
          if serversocket1.Socket.Connections[j-1].SocketHandle=session[i-1].SS_Handle then
          begin
            serversocket1.Socket.Connections[j-1].Close;{断开客户机}
            break;
          end;
      end;
     end;
 end;
end.
    三、总结
    由于这种设计思路仅仅在被代理端和远程主机之间增加了一个重定向功能,被代理端原有的缓存技术等特点均保留,因此效率较高。经过测试,利用1个33.6K的Modem上网时,三到十个被代理工作站同时上网,仍有较好的响应速度。由于被代理工作站和代理服务器之间的连接一般通过高速链路,因此瓶颈主要出现在代理服务器的上网方式上。 通过上述方法,作者成功开发了一套完善的代理服务器软件并与机房计费系统完全集成,实现了利用一台工作站完成上网代理、上网计费、用机计费等功能。 有编程经验的朋友完全可以另行增加代理服务器功能,如设定禁止访问站点、统计客户流量、Web访问列表等等。

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