.

wcfs/δbtail.go

@@ -209,8 +209,13 @@ func (δBtail *ΔBtail) Track(path []Node, flags TrackFlags) {	// XXX Tree|Bucke
 	// XXX assert Tree Tree ... Tree Bucket
 	root := treeRoot.POid()
 
+	oidv := []Oid{}
+	for _, node := range path { oidv = append(oidv, node.POid()) }
+	fmt.Printf("Track %v\n", oidv)
+
 	for _, node := range path {
 		oid := node.POid()
+		// XXX check for InvalidOid  (e.g. T/B1:a with bucket not having its own oid.
 		nodeRoots, ok := δBtail.trackIdx[oid]
 		if !ok {
 			nodeRoots = make(SetOid)
@@ -325,11 +330,14 @@ func (δBtail *ΔBtail) treediff(ctx context.Context, root zodb.Oid, δZT SetOid
 
 	fmt.Printf("treediff %s  δZT: %v\n", root, δZT)
 
+	// XXX δZT -> δZT* (all changed nodes are connected)
+	// e.g. t₀->t₁->b₂   δZ={t₀ b₂}  ->  δZ*=δZ+{t₁}
+
 	δT = map[Key]Value{}
 
-	for oid := range δZT {
-		xa, err1 := zconnOld.Get(ctx, oid)
-		xb, err2 := zconnNew.Get(ctx, oid)
+	for top := range δZT { // XXX -> for each top-level nodes in δZT*
+		xa, err1 := zconnOld.Get(ctx, top)
+		xb, err2 := zconnNew.Get(ctx, top)
 		err := xerr.Merge(err1, err2)
 		if err != nil {
 			return nil, err
@@ -338,40 +346,101 @@ func (δBtail *ΔBtail) treediff(ctx context.Context, root zodb.Oid, δZT SetOid
 		ta := zodb.ClassOf(xa)
 		tb := zodb.ClassOf(xb)
 		if ta != tb {
-			return nil, fmt.Errorf("object %s: type mutated: %s -> %s", oid, ta, tb)
+			return nil, fmt.Errorf("object %s: type mutated: %s -> %s", top, ta, tb)
 		}
 
 		// XXX activate/deactivate
+		var δtop map[Key]Value
 
 		switch a := xa.(type) {
 		default:
-			return nil, fmt.Errorf("object %s: type unexpected: %s", oid, ta)
+			return nil, fmt.Errorf("object %s: type unexpected: %s", top, ta)
+
+		case *Tree:
+			fmt.Printf("  T%s\n", a.POid())
+			b := xb.(*Tree)   // must not fail
+			δtop, err = diffT(ctx, a, b, δZT*)
 
 		case *Bucket:
+			fmt.Printf("  B%s\n", a.POid())
 			b := xb.(*Bucket) // must not fail
-			δb, err := diffB(ctx, a, b)
+			δtop, err = diffB(ctx, a, b)
+		}
+
 		if err != nil {
 			return nil, err
 		}
-			for k,v := range δb {
+		for k,v := range δtop {
 			δT[k] = v
 		}
+	}
 
-		// XXX stub
-		case *Tree:
-			b := xb.(*Tree)   // must not fail
-			// TODO handle
-			_ = b
+	return δT, nil
+}
+
+// diffT computes difference in between two revisions of substree.
+// δZTC is connected set of objects covering δZT (objects changed in this tree)
+func diffT(ctx context.Context, a, b *Tree, δZTC SetOid) (δ map[Key]Value, err error) {
+	defer xerr.Contextf(&err, "diffT %s", a.POid())
+	if a.POid() != b.POid() {
+		panic("different trees")
+	}
+
+	err = a.PActivate(ctx);  if err != nil { return nil, err }
+	defer a.PDeactivate()
+	err = b.PActivate(ctx);  if err != nil { return nil, err }
+	defer b.PDeactivate()
+
+	av := a.Entryv() // key↑
+	bv := b.Entryv() // key↑
+	δ   = map[Key]Value{}
+
+	// [i].Key ≤ [i].Child.*.Key < [i+1].Key  i ∈ [0, len([]))
+	//
+	// [0].Key       = -∞ ; always returned so
+	// [len(ev)].Key = +∞ ; should be assumed so
+	aChildren := SetOid{}
+	bChildren := SetOid{}
+	for _, __ := range av { aChildren.Add(__.Child().POid()) } // InvalidOid = embedded bucket
+	for _, __ := range bv { bChildren.Add(__.Child().POid()) } // ----//----
+	allChildren := SetOid{}; allChildren.Update(aChildren); allChildren.Update(bChildren)
+
+	del := SetOid{}
+	add := SetOid{}
+	mod := SetOid{}
+
+	for child := range allChildren {
+		// add/del/modify, but child is not tracked - ignore
+		if !δZTC.Has(child) {
+			continue
+		}
+
+		ina := aChildren.Has(child)
+		inb := bChildren.Has(child)
+		switch {
+		case ina && inb:	mod.Add(child)
+		case ina:		del.Add(child)
+		case inb:		add.Add(child)
+		default:		panic("unreachable")
 		}
 	}
 
-	return δT, nil
+	for child := range del { // XXX sorted ?
+		δc, err := delChild(ctx, child, δZTC) // -> removal + remove child and its children from tracked
+		// XXX err
+	}
+	for child := range add { // XXX sorted ?
+		δc, err := addChild(ctx, child, δZTC) // -> addd + add child and its children into tracked
+	}
+	for child := range mod { // XXX sorted ?
+
+	}
 }
 
 // diffB computes difference in between two revisions of a bucket.
-// the buckets must be already activated
 func diffB(ctx context.Context, a, b *Bucket) (δ map[Key]Value, err error) {
 	defer xerr.Contextf(&err, "diffB %s", a.POid())
+	// XXX oid can be InvalidOid for T/B... (i.e. B is part of T and is not yet committed separately)
 	if a.POid() != b.POid() {
 		panic("different buckets")
 	}

wcfs/δbtail_test.go

@@ -567,6 +567,8 @@ func xverifyΔBTail1(t *testing.T, subj string, db *zodb.DB, treeRoot zodb.Oid,
 		}
 	}
 
+	// XXX verify δbtail index consistency against @at1
+
 	// δB <- δZ
 	δB, err := δbtail.Update(δZ); X(err)
 	if δB.Rev != δZ.Tid {
@@ -574,6 +576,8 @@ func xverifyΔBTail1(t *testing.T, subj string, db *zodb.DB, treeRoot zodb.Oid,
 		return
 	}
 
+	// XXX verify δbtail index consistency against @at2
+
 
 	// assert δB.ByRoot == {treeRoot -> ...}  if inδTOK != ø
 	//                  == ø                  if inδTOK == ø