rephrase tcp.Value methods; add Ring.FreeLimited; work on TxQueue

tcp/valuesize.go

@@ -24,24 +24,24 @@ type Value uint32
 type Size uint32
 
 // LessThan checks if v is before w (modulo 32) i.e., v < w.
-func LessThan(v, w Value) bool {
+func (v Value) LessThan(w Value) bool {
 	return int32(v-w) < 0
 }
 
 // LessThanEq returns true if v==w or v is before (modulo 32) i.e., v < w.
-func LessThanEq(v, w Value) bool {
-	return v == w || LessThan(v, w)
+func (v Value) LessThanEq(w Value) bool {
+	return v == w || v.LessThan(w)
 }
 
 // InRange checks if v is in the range [a,b) (modulo 32), i.e., a <= v < b.
-func InRange(v, a, b Value) bool {
+func (v Value) InRange(a, b Value) bool {
 	return v-a < b-a
 }
 
 // InWindow checks if v is in the window that starts at 'first' and spans 'size'
 // sequence numbers (modulo 32).
-func InWindow(v, first Value, size Size) bool {
-	return InRange(v, first, Add(first, size))
+func (v Value) InWindow(first Value, size Size) bool {
+	return v.InRange(first, Add(first, size))
 }
 
 // Add calculates the sequence number following the [v, v+s) window.