.

wcfs/δbtail.go

@@ -425,6 +425,7 @@ func (δBtail *ΔBtail) Track(key Key, keyPresent bool, path []Node) error { //
 }
 
 // XXX place
+// XXX doc
 func (tidx trackIndex) AddPath(path []Node) { // XXX Tree|Bucket; path[0] = root
 	l := len(path)
 	if l == 0 {
@@ -599,6 +600,16 @@ type nodeInRange struct {
 	done     bool // whether this node was already taken into account while computing diff
 }
 
+// XXX place, doc
+func (n *nodeInRange) NodePath() []Node {
+	path := []Node{}
+	for n != nil {
+		path = append([]Node{n.node}, path...)
+		n = n.parent
+	}
+	return path
+}
+
 // rangeSplit represents set of nodes covering a range.
 // nodes come with key↑ and no intersection in between their [lo,hi)
 type rangeSplit []*nodeInRange // key↑
@@ -664,9 +675,10 @@ func (prs *rangeSplit) Expand(rnode *nodeInRange) (children rangeSplit) {
 		}
 
 		children = append(children, &nodeInRange{
-					lo:   lo,
-					hi_:  hi_,
-					node: treev[i].Child(),
+					parent: rnode,
+					lo:     lo,
+					hi_:    hi_,
+					node:   treev[i].Child(),
 		})
 	}
 
@@ -900,8 +912,8 @@ func diffT(ctx context.Context, A, B *Tree, δZTC SetOid, trackIdx trackIndex, h
 
 	// initial split ranges for A and B
 	// XXX maybe walk till a from root to get more precise initial range?
-	atop := &nodeInRange{lo: KeyMin, hi_: KeyMax, node: A} // [-∞, ∞)
-	btop := &nodeInRange{lo: KeyMin, hi_: KeyMax, node: B} // [-∞, ∞)
+	atop := &nodeInRange{lo: KeyMin, hi_: KeyMax, node: A} // [-∞, ∞) XXX parent?
+	btop := &nodeInRange{lo: KeyMin, hi_: KeyMax, node: B} // [-∞, ∞) XXX parent?
 	Av := rangeSplit{atop} // nodes expanded from A
 	Bv := rangeSplit{btop} // nodes expanded from B