.

wcfs/δbtail.go

@@ -82,7 +82,9 @@ type Value  = zodb.Oid // XXX assumes key points to IPersistent
 // ΔBTail is not safe for concurrent access.
 // XXX -> multiple readers / single writer?
 type ΔBtail struct {
-	δZtail *zodb.ΔTail // raw ZODB changes; Kept to rebuild δBtail/byRoot after new Track
+	// raw ZODB changes; Kept to rebuild δBtail/byRoot after new Track.
+	// includes all changed objects, not only tracked ones.
+	δZtail *zodb.ΔTail
 
 	δRtail []ΔRoots // which BTree were changed; Noted only by keys ∈ tracket subset
 	byRoot map[*Tree]*ΔTreeTail // root -> k/v change history; only for keys ∈ tracket subset
@@ -151,16 +153,9 @@ func newΔTtail() *ΔTreeTail {
 	}
 }
 
-// Head is similar to zodb.ΔTail.Head .		XXX ok?
-func (δBtail *ΔBtail) Head() zodb.Tid {
-	//return δb.head
-	return δBtail.δZtail.Head()
-}
-
-// Tail is similar to zodb.ΔTail.Tail .		XXX ok?
-func (δBtail *ΔBtail) Tail() zodb.Tid {
-	return δBtail.δZtail.Tail()
-}
+// (tail, head] coverage
+func (δBtail *ΔBtail) Head() zodb.Tid { return δBtail.δZtail.Head() }
+func (δBtail *ΔBtail) Tail() zodb.Tid { return δBtail.δZtail.Tail() }
 
 // XXX SliceByRev?
 // XXX ForgetPast
@@ -209,6 +204,8 @@ func (δBtail *ΔBtail) Track(path []Node) {	// XXX Tree|Bucket; path[0] = root
 // Only those objects from δZ that belong to tracked set are guaranteed to be
 // taken into account. In other words a tree history will assuredly include
 // only those keys, that correspond to tracked subset of δZ.
+//
+// δZ should include all objects changed by ZODB transaction.
 func (δBtail *ΔBtail) Update(δZ *zodb.EventCommit) Δ {
 	δBtail.δZtail.Append(δZ.Tid, δZ.Changev)
 

wcfs/δftail.go

@@ -83,9 +83,9 @@ func NewΔFtail(at0 zodb.Tid) *ΔFtail {
 	}
 }
 
-// XXX
-func (δFtail *ΔFtail) Head() zodb.Tid { panic("TODO") }
-func (δFtail *ΔFtail) Tail() zodb.Tid { panic("TODO") }
+// (tail, head] coverage
+func (δFtail *ΔFtail) Head() zodb.Tid { return δFtail.δBtail.Head() }
+func (δFtail *ΔFtail) Tail() zodb.Tid { return δFtail.δBtail.Tail() }
 
 
 // Track adds tree path to tracked set and associates path root with file.
@@ -117,6 +117,8 @@ func (δFtail *ΔFtail) Track(file *BigFile, path []btree.LONode) {
 // Update updates δFtail given raw ZODB changes.
 //
 // It returns change in files space that corresponds to δZ.
+//
+// δZ should include all objects changed by ZODB transaction.
 func (δFtail *ΔFtail) Update(δZ *zodb.EventCommit) ΔF {
 	δB := δFtail.δBtail.Update(δZ)
 	δF := ΔF{Rev: δB.Rev, Change: make(map[*BigFile]SetI64)}