.

wcfs/internal/xbtree/pptreesubset.go

@@ -513,21 +513,3 @@ func (S PPTreeSubSet) ApplyΔ(δ *ΔPPTreeSubSet) {
 	S.xUnionInplace(δ.Add)
 	S.xfixup(+1, δ.δnchildNonLeafs)
 }
-
-
-
-// XXX kill
-// XXX returns PPTreeSubSet that corresponds to nodes that correspond to δtkeycov.
-// XXX correct?
-func (δ *ΔPPTreeSubSet) XXXδtkeycovSet() (S PPTreeSubSet) {
-	S = PPTreeSubSet{}
-	δ.Del.verify()
-	δ.Add.verify()
-	defer S.verify()
-
-	//S.xfixup(-1, δ.δnchildNonLeafs)
-	S.xUnionInplace(δ.Add)
-	S.xDifferenceInplace(δ.Del)
-	//S.xfixup(+1, δ.δnchildNonLeafs)
-	return S
-}

wcfs/internal/xbtree/δbtail.go

@@ -366,13 +366,23 @@ func (δTtail *ΔTtail) rebuild(root zodb.Oid, δZtail *zodb.ΔTail, db *zodb.DB
 			break
 		}
 
-		widenTrackNew := func() error {
+		err := widenTrackNew(trackNew, δtkeycov, root, δZtail.Head(), db)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return trackNew, nil
+}
+
+// widenTrackNew widens trackNew to cover δtkeycov.
+func widenTrackNew(trackNew PPTreeSubSet, δtkeycov *RangedKeySet, root zodb.Oid, at zodb.Tid, db *zodb.DB) error {
 	// XXX errctx, debug
 
 	txn, ctx := transaction.New(context.TODO()) // XXX
 	defer txn.Abort()
 
-			zhead, err := db.Open(ctx, &zodb.ConnOptions{At: δZtail.Head()});  /*X*/ if err != nil { return err }
+	zhead, err := db.Open(ctx, &zodb.ConnOptions{At: at});  /*X*/ if err != nil { return err }
 
 	xtree, err := zhead.Get(ctx, root);  /*X*/ if err != nil { return err }
 	tree := xtree.(*Tree) // must succeed	XXX better explicit panic?
@@ -393,17 +403,9 @@ func (δTtail *ΔTtail) rebuild(root zodb.Oid, δZtail *zodb.ΔTail, db *zodb.DB
 		}
 	}
 	return nil
-		}
-
-		err := widenTrackNew()
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	return trackNew, nil
 }
 
+
 // rebuild1 rebuilds δT for single δZ.
 //
 // δtrackNew/δtkeycov represents how trackNew changes when going through `atPrev <- δZ.Rev` .
@@ -510,14 +512,18 @@ func (δBtail *ΔBtail) Update(δZ *zodb.EventCommit) (_ ΔB, err error) {
 	for root, δT1 := range δB1.ByRoot {
 		δTtail := δBtail.vδTbyRoot[root] // must succeed
 
-		// δtkeycov1 != ø   ->  rebuild δTtail
+		// δtkeycov1 != ø   ->  rebuild δTtail with trackNew ~= δtkeycov1
 		if !δT1.δtkeycov1.Empty() && δBtail.δZtail.Len() > 1 {
-			//δTtail.trackNew = ... // ~δtkeycov1
-			//δTtail.trackNew = nil // XXX stub
-			δTtail.trackNew = δT1.δtrack.XXXδtkeycovSet() // ~δtkeycov1  XXX correct?
+			trackNew := PPTreeSubSet{}
+			err := widenTrackNew(trackNew, δT1.δtkeycov1, root, δBtail.Head(), δBtail.db)
+			if err != nil {
+				return ΔB{}, err
+			}
+			// XXX assert δTtail.trackNew.Empty()
+			δTtail.trackNew = trackNew
 
 			// XXX vvv we can skip computing diff for HEAD~..HEAD (we just
-			//     computed it in _Update1)
+			//     computed it in _Update1)? (or not - trackNew is as of @head ?)
 			δtrackSet, err := δTtail.rebuild(root, δBtail.δZtail, δBtail.db)
 			if err != nil {
 				return ΔB{}, err

wcfs/internal/xbtree/δbtail_test.go

@@ -1067,6 +1067,8 @@ func xverifyΔBTail_rebuild(t *testing.T, db *zodb.DB, treeRoot zodb.Oid, t0, t1
 //						// δkv2_2 = t2.δxkv / kadj10(kadj21(kadj12(keys1) | keys2))
 ////						keys12_2 := keys1_2.Union(keys2)
 ////						keys12_0 := kadj10.Map(kadj21.Map(keys12_2))
+
+/*
 						fmt.Printf("\n\n\nKKK\nkeys1=%s  keys2=%s\n", keys1, keys2)
 						fmt.Printf("keys12R2=%s\n", keys12R2)
 
@@ -1077,6 +1079,7 @@ func xverifyΔBTail_rebuild(t *testing.T, db *zodb.DB, treeRoot zodb.Oid, t0, t1
 						fmt.Printf("kadj12: %v\n", kadj12)
 						fmt.Printf("t2.xkv.trackSet(%s) -> %s", keys12R2, t2.xkv.trackSet(keys12R2))
 						fmt.Printf("\n\n\n")
+*/
 
 
 						// δkvX_k12R2 = tX.δxkv / keys12R2