PD：抱歉我的英语不好.
我尝试使用以下代码为RETR命令实现CommandHandler：
procedure TForm1.IdFTPServer1CommandHandlers0Command(ASender: TIdCommand);
var
LContext : TIdFTPServerContext;
vStream: TFileStream;
path: String;
vX: Integer;
LEncoding: IIdTextEncoding;
begin
LEncoding := IndyTextEncoding_8Bit;
LContext := ASender.Context as TIdFTPServerContext;
path := 'D:\indy_in_depth.pdf';
try
vStream := TFileStream.Create(path,fmOpenRead);
//LContext.DataChannel.FtpOperation := ftpRetr;
//LContext.DataChannel.Data := VStream;
LContext.DataChannel.OKReply.SetReply(226,RSFTPDataConnClosed);
LContext.DataChannel.ErrorReply.SetReply(426,RSFTPDataConnClosedAbnormally);
ASender.Reply.SetReply(150,RSFTPDataConnToOpen);
ASender.SendReply;
Memo1.Lines.Add('Sending a file with: ' + IntToStr(vStream.Size) + ' bytes');
//Make control of speed here !
for vX := 1 to vStream.Size do
begin
vStream.Position := vX;
LContext.Connection.IOHandler.Write(vStream,1,False);
if vX mod 10000 = 0 then
Memo1.Lines.Add('Sended byte: ' + IntToStr(vX));
end;
//LContext.DataChannel.InitOperation(False);
//LContext.Connection.IOHandler.Write(vStream);
//LContext.KillDataChannel;
LContext.Connection.Socket.Close;
VStream.Free;
except
on E: Exception do
begin
ASender.Reply.SetReply(550,E.Message);
end;
end;
end;
但Filezilla FTP客户端显示流数据,就像其他命令的一部分.
解决方法
The problem is that i need to limit the speed of download (must be configurable Ex. 1 KB/s,1 MB/s,etc.) and i don’t make it work. I know some props like
BitsPerSec,etc. but this only affect the protocol data exchange,not the file exchange withRETRcommand.
BitsPerSec是TIdInterceptThrottler类的属性(以及RecvBitsPerSec和SendBitsPerSec属性).可以通过其Intercept属性将该类的实例分配给任何TIdTCPConnection对象.这不仅限于命令连接,它也可以用于传输连接.
您可以通过TIdFTPServerContext.DataChannel.FDataChannel成员访问TIdFTPServer中文件传输的TIdTCPConnection对象,例如在OnRetrieveFile事件中：
type
// the TIdDataChannel.FDataChannel member is 'protected',// so use an accessor class to reach it...
TIdDataChannelAccess = class(TIdDataChannel)
end;
procedure TForm1.IdFTPServer1RetrieveFile(ASender: TIdFTPServerContext;
const AFileName: TIdFTPFileName; var VStream: TStream);
var
Conn: TIdTCPConnection;
begin
Conn := TIdDataChannelAccess(ASender.DataChannel).FDataChannel;
if Conn.Intercept = nil then
Conn.Intercept := TIdInterceptThrottler.Create(Conn);
TIdInterceptThrottler(Conn.Intercept).BitsPerSec := ...;
VStream := TFileStream.Create(AFileName,fmOpenRead or fmShareDenyWrite);
end;
另一种方法是创建自己的T(File)Stream派生类,以覆盖虚拟的Read()和Write()方法,根据需要执行自己的限制,然后将该类的实例分配给OnRetrieveFile的VStream参数,OnStoreFile事件.
I see in
IdFTPServer.pas,and the Stream is converted to string and send with a repeat/until loop (with IOHandler.Write())
不,流不会转换为字符串.你误读了代码.在对IOHandler.Write(TStream)方法的单个调用中,流的内容将作为二进制数据原样发送.
but i need some form of control the upload/download process and be able to limit the speed for all incoming client connections.
往上看.
I try to implement a CommandHandler for the RETR command
您不应该直接处理RETR命令. TIdFTPServer已经为您做到了这一点.您打算使用OnRetrieveFile事件来准备下载,并使用OnStoreFile事件进行上载.