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基于IOCP的高速文件传输代码

//服务端:

const
  //transmit用的参数
  TF_USE_KERNEL_APC     = $20;
  //命令类型
  CMD_CapScreen             = 2000;
  CMD_CapVideo              = 2001;
  CMD_CapAudio              = 2002;
  CMD_GetSystemInfo         = 2003;
  CMD_TransmitFiles         = 2004;
  
//通用数据传输包体封装
type
  //每个完整数据的头描述
  TPacketHeader =  packed record
     PacketCMD    : Word;   //包类型
     DataLength   : Word;   //包体长度
     IsCompressed : Boolean//包体是否为压缩数据
  end;
  TBytes = array [0..65535of Byte;
  TPacketBody = packed record
     Data : TBytes;
  end;
  //完整的数据包
  TPacketInfo = packed record
    Header : TPacketHeader;
    Body   : TPacketBody;
  end;
  //文件发送包
  TFileSendPacket = packed record
    FileName : array [0..127of Char;
    FileSize : LongWord;
    StartWritePositon : LongWord;
    hFile : THandle;
  end;
function TServerClientSocket.TransFile(FileName: string;StartWritePositon:LongWord): Boolean;
var
  hFile : THandle;
  NumberOfByteSend : LongWord;
  Block:PBlock;
  PacketInfo: TPacketInfo;
  FileSendPacket : TFileSendPacket;
  AFileName : string[128];
  TransmitFileBuffers : TTransmitFileBuffers;
begin
    if not FileExists(FileName) then
    begin
      Result := False;
      Exit;
    end;
    
    hFile := CreateFile(PChar(FileName), GENERIC_READ, FILE_SHARE_READ, nil, OPEN_EXISTING, 00);
    //如果文件打开错误,则退出
    if hFile = INVALID_HANDLE_VALUE then
    begin
      Result := False;
      Closehandle(hFile);
      Exit;
    end;
    //得到需要传输的字节数
    NumberOfByteSend := windows.GetFileSize(hFile, nil) - StartWritePositon;
    if NumberOfByteSend <= 0 then
    begin
      Closehandle(hFile);
      Exit;
    end;
    Block := AllocBlock;
    Block.Data.Event := seFileSend;
    Block.Data.Overlapped.Offset := StartWritePositon;
    AFileName := ExtractFileName(FileName);
    FillChar(PacketInfo,SizeOf(TPacketInfo),0);
    FillChar(FileSendPacket,SizeOf(TFileSendPacket),0);
    Move(AFileName[1],FileSendPacket.FileName,length(AFileName));
    FileSendPacket.FileSize := NumberOfByteSend;
    FileSendPacket.StartWritePositon := StartWritePositon;
    FileSendPacket.hFile := hFile;
    PacketInfo.Header.PacketCMD := CMD_TransmitFiles;
    PacketInfo.Header.DataLength := Sizeof(TFileSendPacket);
    PacketInfo.Header.IsCompressed := False;
    Move(FileSendPacket,PacketInfo.Body.Data,SizeOf(TFileSendPacket));
    Move(PacketInfo,Block^.Data.Buffer,SizeOf(TPacketHeader) + SizeOf(TFileSendPacket));
    //传输文件前发送的包
    TransmitFileBuffers.Head := @Block^.Data.Buffer[0];
    TransmitFileBuffers.HeadLength := SizeOf(TPacketHeader) + SizeOf(TFileSendPacket);
    //传输文件完毕后发送的包
    TransmitFileBuffers.Tail := nil;
    TransmitFileBuffers.TailLength := 0;
    LogMsg('开始发送文件:' + FileName + ' Size=' + IntToStr(NumberOfByteSend));
    //发送命令,并将文件名、继传点、需要传输的大小传递过去
    if not TransmitFile(SocketHandle, hFile, NumberOfByteSend, MAX_BUFSIZE,
      @Block^.Data.Overlapped, @TransmitFileBuffers, TF_USE_KERNEL_APC) then
    begin
      if GetLastError <> ERROR_IO_PENDING then
      begin
        Result := False;
        Exit;
      end;
    end;
    Result := True;
end;
//如果发送完毕,可以接收到重叠IO的返回结果
    case Block^.Data.Event of
      seFileSend:
      begin
        Block.IsUse := False;
        Move(Block.Data.Buffer,PacketInfo,SizeOf(TPacketHeader) + SizeOf(TFileSendPacket));
        if PacketInfo.Header.PacketCMD = CMD_TransmitFiles then
        begin
           FillChar(FileSendPacket,SizeOf(TFileSendPacket),0);
           Move(PacketInfo.body.data,FileSendPacket,SizeOf(TFileSendPacket));
           Closehandle(FileSendPacket.hFile); //发送完毕,关闭文件句柄
        end;
        LogMsg('文件:' + StrPas(FileSendPacket.FileName) + '  发送完毕!');
        if not PrepareRecv() then Result := RESPONSE_FAIL;       
      end;
      seRead: 。。。。。。。
  
//客户端:
procedure TrecvThread.Execute;
var PacketInfo : TPacketInfo;
    str: string;
    FileSendPacket:TFileSendPacket;
    FileStream:TFileStream;
    FileName :string;
    RecBuf:array[0..1023of Char;
    RemainByts,RecvedBytes:Integer;
begin
  while (not self.Terminated ) DO
  begin
    cs.CheckForDisconnect(False);
     if cs.ClosedGracefully then
     begin
        Fmm.Lines.Add('链路断开!');
        self.Terminate;
     end;
     cs.ReadBuffer(PacketInfo.Header,SizeOf(TPacketHeader));
     cs.ReadBuffer(PacketInfo.Body.Data, PacketInfo.Header.DataLength);
     if PacketInfo.Header.PacketCMD = CMD_TransmitFiles then
     begin
       Move(PacketInfo.Body.Data,FileSendPacket,PacketInfo.Header.DataLength);
       FileName := StrPas(FileSendPacket.FileName);
       try
         FileStream := TFileStream.Create('C:\'+ FileName, fmCreate or fmOpenWrite);
         Fmm.Lines.Add('接收:' + FileName + ' Size=' + IntToStr(FileSendPacket.FileSize));
         RecvedBytes := 0;
         while (RecvedBytes < FileSendPacket.FileSize) do
         begin
           if FileSendPacket.FileSize <= 1024 then
           begin
             cs.ReadBuffer(RecBuf,FileSendPacket.FileSize);
             RecvedBytes := FileSendPacket.FileSize;
             FileStream.WriteBuffer(RecBuf,RecvedBytes);
             Break;
           end else begin
             cs.ReadBuffer(RecBuf,1024);
             RecvedBytes := RecvedBytes + 1024;
             FileStream.WriteBuffer(RecBuf,1024);
             RemainByts := FileSendPacket.FileSize - RecvedBytes;
             if RemainByts <= 1024 then
             begin
               cs.ReadBuffer(RecBuf,RemainByts);
               RecvedBytes := RecvedBytes + RemainByts;
               FileStream.WriteBuffer(RecBuf,RemainByts);
               Break;
             end;
           end;
         end;
       finally
          FileStream.Free;
       end;
     end;
  end;
end;

 

http://www.delphi6.com/thread-554.htm

基于IOCP的高速文件传输代码