.

wcfs/internal/xbtree/δbtail.go

@@ -245,7 +245,9 @@ func (btail *ΔTail) GetAt(root *Tree, key Key, at zodb.Tid) (value Value, ok bo
 	// XXX key not tracked		-> panic
 	// XXX at not ∈ (tail, head]	-> panic
 
-	// XXX -> index lastXXXOf(key)
+	// XXX stub -> that only ZBlk.rev is used
+
+	// XXX -> index lastXXXOf(key) | linear scan ↓ looking for change <= at
 	δt := btail.byRoot[root]
 	for i := len(δt.δTtail)-1; i >= 0; i-- {
 		δ := δt.δTtail[i]
@@ -272,17 +274,17 @@ func (btail *ΔTail) GetAt(root *Tree, key Key, at zodb.Tid) (value Value, ok bo
 	return
 }
 
-func (btail *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 = btail.lastRevOf[root]
 	rev = lastRevOf[key]
 	while rev > at:
 		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 (btail *ΔTail) ForgetPast(revCut zodb.Tid) {
 	btail.ΔZtail.ForgetPast(revCut) // XXX stub