public void LoadWord()
{
var position = SrcBuffer.Length - BytesAvailable;
int tmpAvailableBytes = BytesAvailable - 4;
int availableBytes = Math.Min(4, BytesAvailable);
//if (availableBytes == 0)
//{
// throw new OverflowException("no bytes available");
//}
ReadOnlySpan <byte> workingBytes = ReadOnlySpan <byte> .Empty;
if (tmpAvailableBytes < 0)
{
var buffer = new byte[4];
Array.Copy(SrcBuffer.Slice(position, BytesAvailable).ToArray(), buffer, BytesAvailable);
workingBytes = buffer;
}
else
{
workingBytes = SrcBuffer.Slice(position, 4);
}
Word = BinaryPrimitives.ReadInt32BigEndian(workingBytes);
// track the amount of this.data that has been processed
BitsAvailable = availableBytes * 8;
BytesAvailable -= availableBytes;
}
public void FullDecode()
{
int offset = 0;
Span <byte> span = new byte[SrcBuffer.Length];
int len = SrcBuffer.Length;
for (int i = 0; i < len; i++)
{
byte tmp;
if ((SrcBuffer.Length - i) >= 2)
{
if (TryDecode(SrcBuffer.Slice(i, 2), out tmp))
{
i++;
}
}
else
{
tmp = SrcBuffer[i];
}
span[offset++] = tmp;
}
Reader = span.Slice(0, offset);
}
/// <summary>
/// 在解码的时候把校验和也计算出来，避免在循环一次进行校验
/// </summary>
/// <returns></returns>
public void Decode(Span <byte> allocateBuffer)
{
int i = 0;
int offset = 0;
int len = SrcBuffer.Length;
_realCheckXorCode = 0;
allocateBuffer[offset++] = SrcBuffer[0];
// 取出校验码看是否需要转义
ReadOnlySpan <byte> checkCodeBufferSpan = SrcBuffer.Slice(len - 3, 2);
int checkCodeLen = 1;
if (checkCodeBufferSpan.SequenceEqual(decode7d01))
{
_realCheckXorCode = 0x7d;
checkCodeLen += 1;
}
else if (checkCodeBufferSpan.SequenceEqual(decode7d02))
{
_realCheckXorCode = 0x7e;
checkCodeLen += 1;
}
else
{
_realCheckXorCode = checkCodeBufferSpan[1];
}
len = len - checkCodeLen - 1 - 1;
ReadOnlySpan <byte> tmpBufferSpan = SrcBuffer.Slice(1, len);
while (i < len)
{
if (tmpBufferSpan[i] == 0x7d)
{
if (len > i + 1)
{
if (tmpBufferSpan[i + 1] == 0x01)
{
allocateBuffer[offset++] = 0x7d;
_calculateCheckXorCode = (byte)(_calculateCheckXorCode ^ 0x7d);
i++;
}
else if (tmpBufferSpan[i + 1] == 0x02)
{
allocateBuffer[offset++] = 0x7e;
_calculateCheckXorCode = (byte)(_calculateCheckXorCode ^ 0x7e);
i++;
}
else
{
allocateBuffer[offset++] = tmpBufferSpan[i];
_calculateCheckXorCode = (byte)(_calculateCheckXorCode ^ tmpBufferSpan[i]);
}
}
}
else
{
allocateBuffer[offset++] = tmpBufferSpan[i];
_calculateCheckXorCode = (byte)(_calculateCheckXorCode ^ tmpBufferSpan[i]);
}
i++;
}
allocateBuffer[offset++] = _realCheckXorCode;
allocateBuffer[offset++] = SrcBuffer[SrcBuffer.Length - 1];
_checkXorCodeVali = (_calculateCheckXorCode == _realCheckXorCode);
Reader = allocateBuffer.Slice(0, offset);
_decoded = true;
}
/// <summary>
/// 在解码的时候把校验和也计算出来，避免在循环一次进行校验
/// </summary>
/// <returns></returns>
public void Decode(Span <byte> allocateBuffer)
{
int offset = 0;
int len = SrcBuffer.Length;
allocateBuffer[offset++] = SrcBuffer[0];
// 取出校验码看是否需要转义
// 正常的 4A 4A 5D
// 单个转义1 00 5A 02 4A 5D
// 单个转义2 00 4A 5A 02 5D
// 两个转义 5A 02 5A 02 5D
// 两个转义 5A 02 02 5A 02 5D
ReadOnlySpan <byte> checkCodeBufferSpan1 = SrcBuffer.Slice(len - 5, 4);
byte checkCodeLen = 0;
byte crcIndex = 0;
(int Index, byte Value)Crc1 = (-1, 0);
(int Index, byte Value)Crc2 = (-1, 0);
for (int i = 0; i < checkCodeBufferSpan1.Length; i++)
{
if ((checkCodeBufferSpan1.Length - i) >= 2)
{
if (TryDecode(checkCodeBufferSpan1.Slice(i, 2), out byte tmp))
{
if (crcIndex > 0)
{
Crc2.Index = i;
Crc2.Value = tmp;
}
else
{
Crc1.Index = i;
Crc1.Value = tmp;
}
crcIndex++;
i++;
}
}
}
if (Crc1.Index >= 0 && Crc2.Index > 0)
{
byte[] crc = new byte[2];
//有两个需要转义的
crc[0] = Crc1.Value;
crc[1] = Crc2.Value;
checkCodeLen += 4;
_realCheckCRCCode = ReadUInt16(crc);
}
else if (Crc1.Index >= 0 && Crc2.Index == -1)
{
byte[] crc = new byte[2];
if ((checkCodeBufferSpan1.Length - Crc1.Index) > 2)
{
//最开始有一个需要转义的
crc[0] = Crc1.Value;
crc[1] = checkCodeBufferSpan1.Slice(Crc1.Index + 2, 1)[0];
}
else
{
//最末尾有一个需要转义的
crc[0] = checkCodeBufferSpan1.Slice(Crc1.Index - 1, 1)[0];
crc[1] = Crc1.Value;
}
_realCheckCRCCode = ReadUInt16(crc);
//存在一个转义的
checkCodeLen += 3;
}
else
{
//最后两位不是转义的
checkCodeLen += 2;
_realCheckCRCCode = ReadUInt16(SrcBuffer.Slice(len - 3, 2));
}
//转义数据长度=len-校验码长度-头-尾
len = len - checkCodeLen - 1 - 1;
ReadOnlySpan <byte> tmpBufferSpan = SrcBuffer.Slice(1, len);
for (int i = 0; i < tmpBufferSpan.Length; i++)
{
byte tmp;
if ((tmpBufferSpan.Length - i) >= 2)
{
if (TryDecode(tmpBufferSpan.Slice(i, 2), out tmp))
{
i++;
}
}
else
{
tmp = tmpBufferSpan[i];
}
allocateBuffer[offset++] = tmp;
_calculateCheckCRCCode = (ushort)((_calculateCheckCRCCode << 8) ^ (ushort)CRCUtil.CRC[(_calculateCheckCRCCode >> 8) ^ tmp]);
}
allocateBuffer[offset++] = (byte)(_calculateCheckCRCCode >> 8);
allocateBuffer[offset++] = (byte)_calculateCheckCRCCode;
allocateBuffer[offset++] = SrcBuffer[SrcBuffer.Length - 1];
_checkCRCCodeVali = (_calculateCheckCRCCode == _realCheckCRCCode);
Reader = allocateBuffer.Slice(0, offset);
_decoded = true;
}
/// <summary>
/// 在解码的时候把校验和也计算出来，避免在循环一次进行校验
/// </summary>
/// <returns></returns>
public void Decode(Span <byte> allocateBuffer)
{
int offset = 0;
int len = SrcBuffer.Length;
allocateBuffer[offset++] = SrcBuffer[0];
// 取出校验码看是否需要转义
ReadOnlySpan <byte> checkCodeBufferSpan1 = SrcBuffer.Slice(len - 3, 2);
int checkCodeLen = 0;
if (TryDecode(checkCodeBufferSpan1, out byte value1))
{
//最后两位是转义的
byte[] tmpCrc2 = new byte[2];
checkCodeLen += 2;
tmpCrc2[1] = value1;
//从最后往前在取两位进行转义
ReadOnlySpan <byte> checkCodeBufferSpan2 = SrcBuffer.Slice(len - 5, 2);
if (TryDecode(checkCodeBufferSpan2, out byte value2))
{
//转义成功
tmpCrc2[0] = value2;
checkCodeLen += 2;
}
else
{
//转义不成功取当前最后一位
tmpCrc2[0] = checkCodeBufferSpan2[1];
checkCodeLen += 1;
}
_realCheckCRCCode = ReadUInt16(tmpCrc2);
}
else
{
//最后两位不是转义的
_realCheckCRCCode = ReadUInt16(checkCodeBufferSpan1);
checkCodeLen += 2;
}
//转义数据长度
len = len - checkCodeLen - 1 - 1;
ReadOnlySpan <byte> tmpBufferSpan = SrcBuffer.Slice(1, len);
for (int i = 0; i < tmpBufferSpan.Length; i++)
{
byte tmp = 0;
if ((tmpBufferSpan.Length - i) >= 2)
{
if (TryDecode(tmpBufferSpan.Slice(i, 2), out tmp))
{
i++;
}
}
else
{
tmp = tmpBufferSpan[i];
}
allocateBuffer[offset++] = tmp;
_calculateCheckCRCCode = (ushort)((_calculateCheckCRCCode << 8) ^ (ushort)CRCUtil.CRC[(_calculateCheckCRCCode >> 8) ^ tmp]);
}
allocateBuffer[offset++] = (byte)(_calculateCheckCRCCode >> 8);
allocateBuffer[offset++] = (byte)_calculateCheckCRCCode;
allocateBuffer[offset++] = SrcBuffer[SrcBuffer.Length - 1];
_checkCRCCodeVali = (_calculateCheckCRCCode == _realCheckCRCCode);
Reader = allocateBuffer.Slice(0, offset);
_decoded = true;
}