.

wcfs/internal/xbtree/δbtail.go

@@ -195,27 +195,34 @@ func (δb *ΔTail) Track(path []Node) {	// XXX Tree|Bucket; path[0] = root
 // taken into account. In other words a tree history will assuredly include
 // only those keys, that correspond to tracked subset of δZ.
 //
-// XXX return -> [] of (root, []key) that are invalidated.
-// XXX -> + separate SliceByRev? or Data to get diff?
-func (δB *ΔTail) Update(δZ *zodb.EventCommit) {
-/*
-	.δZtail += δZ
-*/
-	δB.update()
-}
+// XXX returned [](root, []key) -> move to separate SliceByRev to get diff?
+func (btail *ΔTail) Update(δZ *zodb.EventCommit) (δB ΔRevEntry) {
+	btail.δZtail.Append(δZ.Tid, δZ.Changev)
 
-// update brings .δBtail up to date by recomputing diff XXX and taking new
-// entries in .δZtail into account.
-func (δB *ΔTail) update() {
-/*
-	δbZ = {}
-	for δ in δZ:
-		.trackIdx[δ]:
-			ø	-> nothing
-			root	-> δbZ[root] += δ
+	// {} root -> []oid changed under that root
+	δZByRoot := map[*Tree][]zodb.Oid{}	// XXX -> map[*Tree]SetOid ?
+	for _, δ := range δZ.Changev {
+		roots, ok := btail.trackIdx[δ]
+		if !ok {
+			continue
+		}
+		for root := range roots {
+			δZByRoot[root] = append(δZByRoot[root], δ)
+		}
+	}
+
+	δB.Rev = δZ.Tid
+	if len(δZByRoot) == 0 {
+		return δB // tracked set not changed
+	}
+
+	// XXX stub to get file.size invalidation working
+	for root := range δZByRoot {
+		δB.Changev = append(δB.Changev, ΔTree{root, nil})
+	}
+	return δB
 
-	if δbZ == ø:
-		return
+/*	TODO btree-diff:
 
 	zconnNew = db.Open(δZ.rev)
 	defer(zconnNew.close)
@@ -235,19 +242,23 @@ func (δB *ΔTail) update() {
 */
 }
 
+// update brings .δBtail up to date by recomputing diff XXX and taking new
+// entries in .δZtail into account.
+// func (btail *ΔTail) update()
+
 // XXX -> Get(root, key, at) -> (valueOid, rev) ?
-func (δB *ΔTail) LastRevOf(root Tree, key Key, at zodb.Tid) (_ zodb.Tid, exact bool) {
+func (btail *ΔTail) LastRevOf(root Tree, key Key, at zodb.Tid) (_ zodb.Tid, exact bool) {
 /*
-	lastRevOf = δB.lastRevOf[root]
+	lastRevOf = btail.lastRevOf[root]
 	rev = lastRevOf[key]
 	while rev > at:
-		rev = scan δB.δBtail ↓ looking for change(key)	# XXX linear scan
+		rev = scan btail.δBtail ↓ looking for change(key)	# XXX linear scan
 	return rev
 
 */
 	return 0, false // XXX stub (saying take only ZBlk.rev into account)
 }
 
-func (δB *ΔTail) ForgetPast(revCut zodb.Tid) {
-	δB.δZtail.ForgetPast(revCut) // XXX stub
+func (btail *ΔTail) ForgetPast(revCut zodb.Tid) {
+	btail.δZtail.ForgetPast(revCut) // XXX stub
 }

wcfs/misc.go

@@ -705,8 +705,7 @@ func (δf *ΔFTail) Track(file *BigFile, path []btree.LONode) {
 }
 
 func (δf *ΔFTail) Update(δZ *zodb.EventCommit) ΔFentry {
-	δf.ΔTail.Update(δZ)
-	δB := xbtree.ΔRevEntry{} // XXX stub
+	δB := δf.ΔTail.Update(δZ)
 	var changev []ΔFile // δB.Changev root -> file (via .fileIdx)
 	for _, δ := range δB.Changev {
 		files := δf.fileIdx[δ.Root]