implement a basic store for new connection IDs

conn_id_manager.go

@@ -0,0 +1,45 @@
+package quic
+
+import (
+	"fmt"
+
+	"github.com/lucas-clemente/quic-go/internal/utils"
+	"github.com/lucas-clemente/quic-go/internal/wire"
+)
+
+type connIDManager struct {
+	queue utils.NewConnectionIDList
+}
+
+func (h *connIDManager) Add(f *wire.NewConnectionIDFrame) error {
+	// insert a new element at the end
+	if h.queue.Len() == 0 || h.queue.Back().Value.SequenceNumber < f.SequenceNumber {
+		h.queue.PushBack(utils.NewConnectionID{
+			SequenceNumber:      f.SequenceNumber,
+			ConnectionID:        f.ConnectionID,
+			StatelessResetToken: &f.StatelessResetToken,
+		})
+		return nil
+	}
+	// insert a new element somewhere in the middle
+	for el := h.queue.Front(); el != nil; el = el.Next() {
+		if el.Value.SequenceNumber == f.SequenceNumber {
+			if !el.Value.ConnectionID.Equal(f.ConnectionID) {
+				return fmt.Errorf("received conflicting connection IDs for sequence number %d", f.SequenceNumber)
+			}
+			if *el.Value.StatelessResetToken != f.StatelessResetToken {
+				return fmt.Errorf("received conflicting stateless reset tokens for sequence number %d", f.SequenceNumber)
+			}
+			return nil
+		}
+		if el.Value.SequenceNumber > f.SequenceNumber {
+			h.queue.InsertBefore(utils.NewConnectionID{
+				SequenceNumber:      f.SequenceNumber,
+				ConnectionID:        f.ConnectionID,
+				StatelessResetToken: &f.StatelessResetToken,
+			}, el)
+			return nil
+		}
+	}
+	panic("should have processed NEW_CONNECTION_ID frame")
+}