sender.~pas

用Delphi开发语言实现的对网络链路层的连续ARQ协议的仿真。

unit sender;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Sockets, ComCtrls, ExtCtrls, Spin;

type
  TForm1 = class(TForm)
    ListBox1: TListBox;
    TcpClient1: TTcpClient;
    TcpServer1: TTcpServer;
    Button1: TButton;
    Button2: TButton;
    Memo1: TMemo;
    StatusBar1: TStatusBar;
    Button3: TButton;
    Timer0: TTimer;
    SpinEdit1: TSpinEdit;
    Label1: TLabel;
    Timer1: TTimer;
    Timer2: TTimer;
    Timer3: TTimer;
    Timer4: TTimer;
    Timer5: TTimer;
    Timer6: TTimer;
    OpenDialog1: TOpenDialog;
    procedure Button2Click(Sender: TObject);
    procedure Sendframe;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Timer0Timer(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure TcpServer1Accept(Sender: TObject;
      ClientSocket: TCustomIpClient);
    procedure Timer1Timer(Sender: TObject);
    procedure Timer2Timer(Sender: TObject);
    procedure Timer3Timer(Sender: TObject);
    procedure Timer4Timer(Sender: TObject);
    procedure Timer5Timer(Sender: TObject);
    procedure Timer6Timer(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  sends,gets,k:integer;
  send:boolean;
  t1,t2,t3,t4,t5,t6:integer;
implementation

{$R *.dfm}

function checksum(x:integer):integer;
var
  t,y:integer;
begin
  t:= x div 999;
  y:= x-t*999;
  x:=x*1000;
  result:=x+y;
end;

procedure TForm1.Sendframe;
var
sor:integer;
info:string;
begin
  if sends>0 then
    ListBox1.Selected[sends-1]:=false;
    sor:=strtoint(Listbox1.Items.Strings[sends]);
    info:=inttostr(checksum(sor))+inttostr(sends);
    TcpClient1.Connect;
    TcpClient1.Sendln(info);
    TcpClient1.Disconnect;
    ListBox1.Selected[sends]:=true;
    SpinEdit2.Value:=sends;
    sends:=sends+1;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
   Timer0.Enabled:=true;
   Button2.Enabled:=false;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  jiange:integer;
begin
if   Button1.Caption='启动' then begin
     TcpClient1.Active:=true;
     Timer0.Interval:= SpinEdit1.Value *1000;
     TcpServer1.Active:=true;
     Button1.Caption:='暂停发送';
     jiange:=20;
     timer1.Interval:=jiange*1000;
     timer2.Interval:=jiange*1000;
     timer3.Interval:=jiange*1000;
     timer4.Interval:=jiange*1000;
     timer5.Interval:=jiange*1000;
     timer6.Interval:=jiange*1000;
     if sends>0 then Timer0.Enabled:=true;
     end
     else begin
     Timer0.Enabled:=false;
     timer1.Enabled:=false;
     timer2.Enabled:=false;
     timer3.Enabled:=false;
     timer4.Enabled:=false;
     timer5.Enabled:=false;
     timer6.Enabled:=false;
     TcpClient1.Active:=false;
     Button1.Caption:='启动'
     end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
      sends:=0;
      gets:=0;
end;

procedure TForm1.Timer0Timer(Sender: TObject);
begin
  if sends-gets<6 then  begin
  case (sends mod 6) of
  0:begin
  t6:=sends;
  Timer6.Enabled:=true;
  end;
  1:begin
  t1:=sends;
  Timer1.Enabled:=true;
  end;
  2:begin
  t2:=sends;
  Timer2.Enabled:=true;
  end;
  3:begin
  t3:=sends;
  Timer3.Enabled:=true;
  end;
  4:begin
  t4:=sends;
  Timer4.Enabled:=true;
  end;
  5:begin
  t5:=sends;
  Timer5.Enabled:=true;
  end;
end;
    Sendframe;
    end
    else memo1.lines.Append('网络时延过大，发送窗口已满');
end;

procedure TForm1.Button3Click(Sender: TObject);
begin    
close;
end;

procedure TForm1.TcpServer1Accept(Sender: TObject;
  ClientSocket: TCustomIpClient);
var
   temp:string;
   m:integer;
begin
   temp:= ClientSocket.Receiveln;
   delete(temp,1,3);
   m:=strtoint(temp);
   m:=m mod 6;
   memo1.Lines.Add('收到ACK'+inttostr(m));
   if temp=inttostr(gets) then begin
case (gets mod 6)of
   0:begin
   Timer6.Enabled:=false;
   end;
   1:begin
   Timer1.Enabled:=false;
   end;
   2:begin
   Timer2.Enabled:=false;
   end;
   3:begin
   Timer3.Enabled:=false;
   end;
   4:begin
   Timer4.Enabled:=false;
   end;
   5:begin
   Timer5.Enabled:=false;
   end;
end;
   if gets>0 then  ListBox1.Selected[gets-1]:=false;
   ListBox1.Selected[gets]:=true;
   gets:=gets+1;
   end;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
      ListBox1.Selected[sends-1]:=false;
      memo1.Lines.Append('超时重发第'+inttostr(t1)+'帧');
      sends:=t1;
      sendframe;
end;

procedure TForm1.Timer2Timer(Sender: TObject);
begin
      ListBox1.Selected[sends-1]:=false;
      memo1.Lines.Append('超时重发第'+inttostr(t2)+'帧');
      sends:=t2;
      sendframe;
end;

procedure TForm1.Timer3Timer(Sender: TObject);
begin
      ListBox1.Selected[sends-1]:=false;
      memo1.Lines.Append('超时重发第'+inttostr(t3)+'帧');
      sends:=t3;
      sendframe;
end;

procedure TForm1.Timer4Timer(Sender: TObject);
begin
      ListBox1.Selected[sends-1]:=false;
      memo1.Lines.Append('超时重发第'+inttostr(t4)+'帧');
      sends:=t4;
      sendframe;
end;

procedure TForm1.Timer5Timer(Sender: TObject);
begin
      ListBox1.Selected[sends-1]:=false;
      memo1.Lines.Append('超时重发第'+inttostr(t5)+'帧');
      sends:=t5;
      sendframe;
end;

procedure TForm1.Timer6Timer(Sender: TObject);
begin
      ListBox1.Selected[sends-1]:=false;
      memo1.Lines.Append('超时重发第'+inttostr(t6)+'帧');
      sends:=t6;
      sendframe;
end;

end.