public IEnumerable <PacketMessage> Parse(CircularBlob stream)
{
while (stream.CanRead())
{
// peek everything untill we 100% have the packet.
var opcodePeek = stream.Peek();
var lenType = _db.GetIncoming(opcodePeek);
var lenPayloadPeek = 0;
var payloadOffset = 0;
switch (lenType)
{
case PacketLength.NextByte:
if (!stream.CanRead(1))
{
break;
}
lenPayloadPeek = stream.Peek(1);
payloadOffset = 1;
break;
case PacketLength.NextShort:
if (!stream.CanRead(2))
{
break;
}
lenPayloadPeek = stream.Peek(1) << 8 + stream.Peek(2);
payloadOffset = 2;
break;
case PacketLength.Undefined:
yield return(PacketMessage.Undefined(opcodePeek));
yield break;
default:
lenPayloadPeek = (byte)lenType;
break;
}
if (!stream.CanRead(payloadOffset + lenPayloadPeek))
{
break;
}
// we can read the whole packet, do so.
// do some assertions on the way
var opcode = stream.ReadByte();
Debug.Assert(opcode == opcodePeek);
var lenPayload = 0;
switch (lenType)
{
case PacketLength.NextByte:
lenPayload = stream.ReadByte();
break;
case PacketLength.NextShort:
lenPayload = stream.ReadInt16();
break;
case PacketLength.Undefined:
yield return(PacketMessage.Undefined(opcodePeek));
yield break;
default:
lenPayload = (byte)lenType;
break;
}
Debug.Assert(lenPayload == lenPayloadPeek);
// don't bother creating a new Blob if we're storing nothing.
if (lenPayload == 0)
{
yield return(PacketMessage.Success(opcode, Blob.Empty));
}
else
{
var payload = new byte[lenPayload];
stream.ReadBlock(payload, 0, lenPayload);
yield return(PacketMessage.Success(opcode, new Blob(payload)));
}
}
}