public int Send(ReadOnlySequence <byte> span, object option = null)
{
if (CheckDispose())
{
//检查释放
return(-4);
}
if (mss <= 0)
{
throw new InvalidOperationException($" mss <= 0 ");
}
if (span.Length == 0)
{
return(-1);
}
var offset = 0;
int count;
#region append to previous segment in streaming mode (if possible)
/// 基于线程安全和数据结构的等原因,移除了追加数据到最后一个包行为。
#endregion
#region fragment
if (span.Length <= mss)
{
count = 1;
}
else
{
count = (int)(span.Length + mss - 1) / (int)mss;
}
if (count > IKCP_WND_RCV)
{
return(-2);
}
if (count == 0)
{
count = 1;
}
for (var i = 0; i < count; i++)
{
int size;
if (span.Length - offset > mss)
{
size = (int)mss;
}
else
{
size = (int)span.Length - offset;
}
var seg = SegmentManager.Alloc(size);
span.Slice(offset, size).CopyTo(seg.data);
offset += size;
seg.frg = (byte)(count - i - 1);
snd_queue.Enqueue(seg);
}
#endregion
return(0);
}
public int Input(ReadOnlySpan <byte> data)
{
if (CheckDispose())
{
//检查释放
return(-4);
}
uint temp_una = snd_una;
if (data.Length < IKCP_OVERHEAD)
{
return(-1);
}
var offset = 0;
int flag = 0;
uint maxack = 0;
while (true)
{
uint ts = 0;
uint sn = 0;
uint length = 0;
uint una = 0;
uint conv_ = 0;
ushort wnd = 0;
byte cmd = 0;
byte frg = 0;
if (data.Length - offset < IKCP_OVERHEAD)
{
break;
}
if (IsLittleEndian)
{
conv_ = BinaryPrimitives.ReadUInt32LittleEndian(data.Slice(offset));
offset += 4;
if (conv != conv_)
{
return(-1);
}
cmd = data[offset];
offset += 1;
frg = data[offset];
offset += 1;
wnd = BinaryPrimitives.ReadUInt16LittleEndian(data.Slice(offset));
offset += 2;
ts = BinaryPrimitives.ReadUInt32LittleEndian(data.Slice(offset));
offset += 4;
sn = BinaryPrimitives.ReadUInt32LittleEndian(data.Slice(offset));
offset += 4;
una = BinaryPrimitives.ReadUInt32LittleEndian(data.Slice(offset));
offset += 4;
length = BinaryPrimitives.ReadUInt32LittleEndian(data.Slice(offset));
offset += 4;
}
else
{
conv_ = BinaryPrimitives.ReadUInt32BigEndian(data.Slice(offset));
offset += 4;
if (conv != conv_)
{
return(-1);
}
cmd = data[offset];
offset += 1;
frg = data[offset];
offset += 1;
wnd = BinaryPrimitives.ReadUInt16BigEndian(data.Slice(offset));
offset += 2;
ts = BinaryPrimitives.ReadUInt32BigEndian(data.Slice(offset));
offset += 4;
sn = BinaryPrimitives.ReadUInt32BigEndian(data.Slice(offset));
offset += 4;
una = BinaryPrimitives.ReadUInt32BigEndian(data.Slice(offset));
offset += 4;
length = BinaryPrimitives.ReadUInt32BigEndian(data.Slice(offset));
offset += 4;
}
if (data.Length - offset < length || (int)length < 0)
{
return(-2);
}
switch (cmd)
{
case IKCP_CMD_PUSH:
case IKCP_CMD_ACK:
case IKCP_CMD_WASK:
case IKCP_CMD_WINS:
break;
default:
return(-3);
}
rmt_wnd = wnd;
Parse_una(una);
Shrink_buf();
if (IKCP_CMD_ACK == cmd)
{
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;
}
}
else if (IKCP_CMD_PUSH == cmd)
{
if (Itimediff(sn, rcv_nxt + rcv_wnd) < 0)
{
///instead of ikcp_ack_push
acklist.Enqueue((sn, ts));
if (Itimediff(sn, rcv_nxt) >= 0)
{
var seg = SegmentManager.Alloc((int)length);
seg.conv = conv_;
seg.cmd = cmd;
seg.frg = frg;
seg.wnd = wnd;
seg.ts = ts;
seg.sn = sn;
seg.una = una;
//seg.len = length; 长度在分配时确定，不能改变
if (length > 0)
{
data.Slice(offset, (int)length).CopyTo(seg.data);
}
Parse_data(seg);
}
}
}
else if (IKCP_CMD_WASK == cmd)
{
// ready to send back IKCP_CMD_WINS in Ikcp_flush
// tell remote my window size
probe |= IKCP_ASK_TELL;
}
else if (IKCP_CMD_WINS == cmd)
{
// do nothing
}
else
{
return(-3);
}
offset += (int)length;
}
if (flag != 0)
{
Parse_fastack(maxack);
}
if (Itimediff(this.snd_una, temp_una) > 0)
{
if (cwnd < rmt_wnd)
{
var mss_ = mss;
if (cwnd < ssthresh)
{
cwnd++;
incr += mss_;
}
else
{
if (incr < mss_)
{
incr = mss_;
}
incr += (mss_ * mss_) / incr + (mss_ / 16);
if ((cwnd + 1) * mss_ <= incr)
{
cwnd++;
}
}
if (cwnd > rmt_wnd)
{
cwnd = rmt_wnd;
incr = rmt_wnd * mss_;
}
}
}
return(0);
}