public static byte[] Split(IByteBuffer buffer)
{
var rdx = 0;
var crcBytes = new byte[2];
var crc = 0;
var length = 0;
var valid = false;
while (true)
{
// 可读字节数小于最小报文长度
if (buffer.ReadableBytes < LoraConst.MinLength)
{
return(null);
}
// 确定帧头的位置
if (LoraConst.StartSign != buffer.GetByte(rdx))
{
rdx = GetStartIndex(buffer, LoraConst.StartSign);
}
// 没有找到帧头
if (rdx == -1)
{
return(null);
}
buffer.SetReaderIndex(rdx);
var lengthBytes = new byte[2];
buffer.GetBytes(rdx + 23, lengthBytes);
length = BytesUtil.Bytes2Int16(lengthBytes);
if (buffer.ReadableBytes < LoraConst.MinLength + length)
{
rdx++;
buffer.SetReaderIndex(rdx);
continue;
}
var content = new byte[25 + length];
buffer.GetBytes(rdx, content);
buffer.GetBytes(rdx + 25 + length, crcBytes);
crc = CRC16.calcCrc16(content);
valid = BytesUtil.ByteArrayEquals(crcBytes, BytesUtil.Int16ToBytes((Int16)crc));
if (!valid)
{
rdx++;
buffer.SetReaderIndex(rdx);
continue;
}
var msg = new byte[LoraConst.MinLength + length];
buffer.ReadBytes(msg);
return(msg);
}
}