.

wcfs/δbtail.go

@@ -184,8 +184,9 @@ type ΔBtail struct {
 // XXX place
 // nodeTrack represents tracking information about a node.
 type nodeTrack struct {
-	parent      zodb.Oid // parent node | InvalidOid for root
-	trackedKeys SetKey   // keys tracked under this node; nil for root	XXX only !empty root
+	parent  zodb.Oid // parent node | InvalidOid for root
+	holes   SetKey   // missing keys tracked under this node  XXX nil for root(?) XXX only !empty root
+	trackedKeys SetKey // XXX kill
 }
 
 // ΔB represents a change in BTrees space.
@@ -306,7 +307,7 @@ func (δBtail *ΔBtail) Track(ctx context.Context, key Key, keyPresent bool, pat
 		// XXX check for InvalidOid  (e.g. T/B1:a with bucket not having its own oid.
 		track, oldTrack = δBtail.trackIdx[oid]
 		if !oldTrack {
-			track = nodeTrack{parent: parent, trackedKeys: SetKey{}}
+			track = nodeTrack{parent: parent, holes: SetKey{}, trackedKeys: SetKey{}}
 			δBtail.trackIdx[oid] = track
 			// XXX .trackNew += oid
 		}
@@ -321,6 +322,17 @@ func (δBtail *ΔBtail) Track(ctx context.Context, key Key, keyPresent bool, pat
 		parent = oid
 	}
 
+	// remember tracked holes in trackIdx
+	if !keyPresent {
+		if leafBucket != nil {
+			track.holes.Add(key)
+		} else {
+			// empty tree
+			rootTrack := δBtail.trackIdx[root] // must succeed
+			rootTrack.holes.Add(key)
+		}
+	}
+
 	// tracked += all keys of leaf bucket for every node up to the root
 	fmt.Printf("  oldTrack: %v  leafBucket: %v\n", oldTrack, leafBucket)
 	if !oldTrack && leafBucket != nil {
@@ -360,6 +372,7 @@ func (δBtail *ΔBtail) Track(ctx context.Context, key Key, keyPresent bool, pat
 		}
 	}
 
+
 	_, ok := δBtail.byRoot[root]
 	if !ok {
 		δBtail.byRoot[root] = newΔTtail()
@@ -558,6 +571,7 @@ func (prs *rangeSplit) Expand(rnode *nodeInRange) (children rangeSplit) {
 	// [len(ev)].Key = +∞ ; should be assumed so
 	tree  := rnode.node.(*Tree)
 	treev := tree.Entryv()
+	fmt.Printf("E treev: %v\n", treev)
 	children = make(rangeSplit, 0, len(treev)+1)
 	for i := range treev {
 		lo := rnode.lo
@@ -572,6 +586,8 @@ func (prs *rangeSplit) Expand(rnode *nodeInRange) (children rangeSplit) {
 		children = append(children, &nodeInRange{lo, hi_, treev[i].Child()})
 	}
 
+	fmt.Printf("E children: %s\n", children)
+
 	// del[i]; insert(@i, children)
 	*prs = append(rs[:i], append(children, rs[i+1:]...)...)
 	return children
@@ -739,9 +755,11 @@ func diffT(ctx context.Context, a, b *Tree, δZTC SetOid, trackIdx map[zodb.Oid]
 	// initial phase: expand changed nodes in a till buckets;
 	// XXX changed buckets -> δ-
 	if a != nil {	// XXX kill (always !nil) ?
+		fmt.Println("ZZZ")
 		// XXX maybe walk till a from root to get more precise initial range?
 		atop := &nodeInRange{lo: KeyMin, hi_: KeyMax, node: a} // [-∞, ∞)
 		av  = rangeSplit{atop}
+		fmt.Printf("X av: %s\n", av)
 		aq := []*nodeInRange{atop} // stack
 		for len(aq) > 0 {
 			l := len(aq)
@@ -750,6 +768,8 @@ func diffT(ctx context.Context, a, b *Tree, δZTC SetOid, trackIdx map[zodb.Oid]
 			defer arn.node.PDeactivate()
 
 			children := av.Expand(arn)
+			fmt.Printf("Y children: %s\n", children)
+			fmt.Printf("Y av:       %s\n", av)
 			for _, rchild := range children {
 				coid := rchild.node.POid()
 				if !( δZTC.Has(coid) ||
@@ -758,16 +778,23 @@ func diffT(ctx context.Context, a, b *Tree, δZTC SetOid, trackIdx map[zodb.Oid]
 					continue
 				}
 
-				switch rchild.node.(type) {
+				switch node := rchild.node.(type) {
 				case *Tree:
 					aq = append(aq, rchild)
 
 				case *Bucket:
-					// XXX also -[k]ø (for tracked DEL)
-					δA, err := diffB(ctx, rchild.node.(*Bucket), nil)
+					δA, err := diffB(ctx, node, nil)
 					if err != nil {
 						return nil, err
 					}
+					// also -[k]ø (for tracked holes)
+					track, ok := trackIdx[node.POid()]
+					if !ok {
+						panicf("%s ∈ δZTC, but ∉ trackIdx", vnode(node))
+					}
+					for k := range track.holes {
+						δA[k] = ΔValue{VDEL, VDEL} // ø->ø indicates hole
+					}
 
 					// δ <- δA
 					err = δMerge(δ, δA)
@@ -1386,5 +1413,5 @@ func (rn nodeInRange) String() string {
 }
 
 func (track nodeTrack) String() string {
-	return fmt.Sprintf("{p%s k%s}", track.parent, track.trackedKeys)
+	return fmt.Sprintf("{p%s h%s k%s}", track.parent, track.holes, track.trackedKeys)
 }