/**
*
* when you received a low level packet (eg. UDP packet), call it
*
* @param data
* @return
*/
public int Input(ByteBuf data)
{
int una_temp = snd_una;
int flag = 0, maxack = 0;
if (data == null || data.ReadableBytes() < IKCP_OVERHEAD)
{
return(-1);
}
while (true)
{
bool readed = false;
int ts;
int sn;
int len;
int una;
int conv_;
int wnd;
byte cmd;
byte frg;
if (data.ReadableBytes() < IKCP_OVERHEAD)
{
break;
}
conv_ = data.ReadIntLE();
if (this.conv != conv_)
{
return(-1);
}
cmd = data.ReadByte();
frg = data.ReadByte();
wnd = data.ReadShortLE();
ts = data.ReadIntLE();
sn = data.ReadIntLE();
una = data.ReadIntLE();
len = data.ReadIntLE();
if (data.ReadableBytes() < len)
{
return(-2);
}
switch ((int)cmd)
{
case IKCP_CMD_PUSH:
case IKCP_CMD_ACK:
case IKCP_CMD_WASK:
case IKCP_CMD_WINS:
break;
default:
return(-3);
}
rmt_wnd = wnd & 0x0000ffff;
Parse_una(una);
Shrink_buf();
switch (cmd)
{
case IKCP_CMD_ACK:
if (_itimediff(current, ts) >= 0)
{
Update_ack(_itimediff(current, ts));
}
Parse_ack(sn);
Shrink_buf();
if (flag == 0)
{
flag = 1;
maxack = sn;
}
else if (_itimediff(sn, maxack) > 0)
{
maxack = sn;
}
break;
case IKCP_CMD_PUSH:
if (_itimediff(sn, rcv_nxt + rcv_wnd) < 0)
{
Ack_push(sn, ts);
if (_itimediff(sn, rcv_nxt) >= 0)
{
Segment seg = new Segment(len);
seg.conv = conv_;
seg.cmd = cmd;
seg.frg = frg & 0x000000ff;
seg.wnd = wnd;
seg.ts = ts;
seg.sn = sn;
seg.una = una;
if (len > 0)
{
seg.data.WriteBytes(data, len);
readed = true;
}
Parse_data(seg);
}
}
break;
case IKCP_CMD_WASK:
// ready to send back IKCP_CMD_WINS in Ikcp_flush
// tell remote my window size
probe |= IKCP_ASK_TELL;
break;
case IKCP_CMD_WINS:
// do nothing
break;
default:
return(-3);
}
if (!readed)
{
data.SkipBytes(len);
}
}
if (flag != 0)
{
Parse_fastack(maxack);
}
if (_itimediff(snd_una, una_temp) > 0)
{
if (this.cwnd < this.rmt_wnd)
{
if (this.cwnd < this.ssthresh)
{
this.cwnd++;
this.incr += mss;
}
else
{
if (this.incr < mss)
{
this.incr = mss;
}
this.incr += (mss * mss) / this.incr + (mss / 16);
if ((this.cwnd + 1) * mss <= this.incr)
{
this.cwnd++;
}
}
if (this.cwnd > this.rmt_wnd)
{
this.cwnd = this.rmt_wnd;
this.incr = this.rmt_wnd * mss;
}
}
}
return(0);
}