TDiocpCoderTcpServer数据序列和还原
TDiocpCoderTcpServer数据序列和还原
封装在uDIOCPStreamCoder.pas单元中。
DIOCP tcp默认使用MSGPACK二进制数据序列,MSGPACK序列为流,即可进行网络传输。TCP服务端有使用TBufferLink(内存池)。
流数据放入内存池中:
流数据默认做了大小限制,最大10M。
const
PACK_FLAG = $D10;
//PACK_FLAG + CRC_VALUE + STREAM_LEN + STREAM_DATA
MAX_OBJECT_SIZE = 1024 * 1024 * 10; //最大对象大小 10M , 大于10M 则会认为错误的包。
procedure TIOCPStreamEncoder.Encode(pvDataObject: TObject; const ouBuf: TBufferLink); var lvPACK_FLAG: WORD; lvDataLen, lvWriteIntValue: Integer; lvBuf: TBytes; lvVerifyValue:Cardinal; begin lvPACK_FLAG := PACK_FLAG; TStream(pvDataObject).Position := 0; if TStream(pvDataObject).Size > MAX_OBJECT_SIZE then begin raise Exception.CreateFmt('数据包太大,请在业务层分拆发送,最大数据包[%d]!', [MAX_OBJECT_SIZE]); end; //pack_flag ouBuf.AddBuffer(@lvPACK_FLAG, 2); // lvDataLen := TStream(pvDataObject).Size; // stream data SetLength(lvBuf, lvDataLen); TStream(pvDataObject).Read(lvBuf[0], lvDataLen); //veri value lvVerifyValue := verifyData(lvBuf[0], lvDataLen); ouBuf.AddBuffer(@lvVerifyValue, SizeOf(lvVerifyValue)); // data_len lvWriteIntValue := TByteTools.swap32(lvDataLen); // stream len ouBuf.AddBuffer(@lvWriteIntValue, SizeOf(lvWriteIntValue)); // stream ouBuf.AddBuffer(@lvBuf[0], lvDataLen); end;
内存池数据放入流中:
function TIOCPStreamDecoder.Decode(const inBuf: TBufferLink; pvContext: TObject): TObject; var lvValidCount, lvReadL:Integer; lvPACK_FLAG:Word; lvDataLen: Integer; lvVerifyValue, lvVerifyDataValue:Cardinal; begin Result := nil; //如果缓存中的数据长度不够包头长度, lvValidCount := inBuf.validCount; //pack_flag + head_len + buf_len if (lvValidCount < SizeOf(Word) + SizeOf(Integer) + SizeOf(Integer)) then begin Exit; end; //记录读取位置 inBuf.markReaderIndex; inBuf.readBuffer(@lvPACK_FLAG, 2); if lvPACK_FLAG <> PACK_FLAG then begin //错误的包数据 Result := TObject(-1); exit; end; //veri value inBuf.readBuffer(@lvVerifyValue, SizeOf(lvVerifyValue)); //headlen inBuf.readBuffer(@lvReadL, SizeOf(lvReadL)); lvDataLen := TByteTools.swap32(lvReadL); if lvDataLen > 0 then begin //文件头不能过大 if lvDataLen > MAX_OBJECT_SIZE then begin Result := TObject(-1); exit; end; if inBuf.validCount < lvDataLen then begin //返回buf的读取位置 inBuf.restoreReaderIndex; exit; end; Result := TMemoryStream.Create; TMemoryStream(Result).SetSize(lvDataLen); inBuf.readBuffer(TMemoryStream(Result).Memory, lvDataLen); TMemoryStream(Result).Position := 0; lvVerifyDataValue := verifyData(TMemoryStream(Result).Memory^, lvDataLen); if lvVerifyValue <> lvVerifyDataValue then begin Result.Free; Result := TObject(-2); end; end else begin Result := nil; end; end;
本文来自博客园,作者:{咏南中间件},转载请注明原文链接:https://www.cnblogs.com/hnxxcxg/p/13521333.html