.

wcfs/internal/xbtree/δbtail.go

@@ -842,6 +842,8 @@ func (δBtail *ΔBtail) GetAt(root zodb.Oid, key Key, at zodb.Tid) (value Value,
 //
 // the caller must not modify returned slice.
 //
+// Only tracked keys are guaranteed to be present.
+//
 // Note: contrary to regular go slicing, low is exclusive while high is inclusive.
 //
 // XXX root -> *Tree ?

wcfs/internal/zdata/δftail.go

@@ -502,7 +502,8 @@ func (δFtail *ΔFtail) ForgetPast(revCut zodb.Tid) {
 	δFtail.δBtail.ForgetPast(revCut)
 
 	// XXX locking
-	// XXX keep index which file changed epoch where (similarly to ΔBtail),
+
+	// TODO keep index which file changed epoch where (similarly to ΔBtail),
 	// and, instead of scanning all files, trim vδE only on files that is really necessary.
 	for _, δftail := range δFtail.byFile {
 		δftail.forgetPast(revCut)
@@ -538,7 +539,7 @@ func (δftail *_ΔFileTail) forgetPast(revCut zodb.Tid) {
 //
 // the caller must not modify returned slice.
 //
-// XXX only tracked blocks are guaranteed to be present.
+// Only tracked blocks are guaranteed to be present.
 //
 // Note: contrary to regular go slicing, low is exclusive while high is inclusive.
 func (δFtail *ΔFtail) SliceByFileRev(zfile *ZBigFile, lo, hi zodb.Tid) /*readonly*/[]*ΔFile {
@@ -546,7 +547,6 @@ func (δFtail *ΔFtail) SliceByFileRev(zfile *ZBigFile, lo, hi zodb.Tid) /*reado
 	xtail.AssertSlice(δFtail, lo, hi)
 
 	// XXX locking
-	// XXX rebuild
 
 	// query .δBtail.SliceByRootRev(file.blktab, lo, hi) +
 	// merge δZBlk history with that.