Add round-robin implementation (#66)

* add handler.encapsulateNode

* implement round robin handler approach

* simplify round robin implementation

* leave TODO

* internet.node touch up

* fix conflict resolve f-up

* replace certain ErrShortBuffer with ErrTruncatedFrame error

tcp/conn.go

@@ -329,7 +329,7 @@ func (conn *Conn) Demux(buf []byte, off int) (err error) {
 	conn.mu.Lock()
 	defer conn.mu.Unlock()
 	if off >= len(buf) {
-		return lneto.ErrShortBuffer
+		return lneto.ErrTruncatedFrame // TODO: this check is bad.
 	}
 	raddr, _, id, _, err := internal.GetIPAddr(buf[:off])
 	if err != nil {

tcp/frame.go

@@ -12,13 +12,13 @@ const (
 	sizeHeaderTCP = 20
 )
 
-// NewFrame returns a new TCPFrame with data set to buf.
+// NewFrame returns a new [Frame] with data set to buf.
 // An error is returned if the buffer size is smaller than 20.
 // Users should still call [Frame.ValidateSize] before working
 // with payload/options of frames to avoid panics.
 func NewFrame(buf []byte) (Frame, error) {
 	if len(buf) < sizeHeaderTCP {
-		return Frame{buf: nil}, lneto.ErrShortBuffer
+		return Frame{buf: nil}, lneto.ErrTruncatedFrame
 	}
 	return Frame{buf: buf}, nil
 }
@@ -190,7 +190,7 @@ func (tfrm Frame) ValidateSize(v *lneto.Validator) {
 		v.AddError(lneto.ErrInvalidLengthField)
 	}
 	if off > len(tfrm.RawData()) {
-		v.AddError(lneto.ErrShortBuffer)
+		v.AddError(lneto.ErrTruncatedFrame)
 	}
 }
 

tcp/options.go

@@ -111,13 +111,13 @@ func (op OptionCodec) ForEachOption(opts []byte, fn func(OptionKind, []byte) err
 			continue
 		}
 		if len(opts[off:]) < 1 {
-			return lneto.ErrShortBuffer
+			return lneto.ErrTruncatedFrame
 		}
 		size := int(opts[off]) // Total option length including kind and length bytes.
 		off++
 		dataLen := size - 2 // Data bytes after kind and length.
 		if dataLen < 0 || len(opts[off:]) < dataLen {
-			return lneto.ErrShortBuffer
+			return lneto.ErrTruncatedFrame
 		}
 
 		if !skipSizeValidation {