.

wcfs/internal/xbtree/δbtail.go

@@ -95,8 +95,8 @@ type Value  = zodb.Oid // XXX assumes key points to IPersistent
 //	        {}(key, value)))
 //
 //	# set of k/v @tail for keys that are not changed in (tail, head].
-//	[](root,
-//		{}(key, value))
+//	{} root ->
+//		{}(key, value)
 //
 // A tree nodes become tracked via Track(path) request.
 //
@@ -113,7 +113,9 @@ type Value  = zodb.Oid // XXX assumes key points to IPersistent
 type ΔTail struct {
 	δBtail []ΔRevEntry // BTree changes; Covers keys ∈ tracket subset
 	δZtail *zodb.ΔTail // raw ZODB changes; Kept to rebuild δBtail after new Track
-//	head   zodb.Tid    // δBtail currently has coverage till head], δZtail can have more
+
+	// {} root -> {}k/v @tail for keys that are not changed in (tail, head].
+	atTail map[*Tree]map[Key]Value
 
 	// XXX or ask client provide db on every call?
 	db     *zodb.DB    // to open connections to load new/old tree|buckets