.

wcfs/δbtail.go

@@ -54,8 +54,8 @@ type SetKey = SetI64
 
 // ΔValue represents change in value.
 type ΔValue struct {
-	Vold Value
-	Vnew Value
+	Old Value
+	New Value
 }
 
 
@@ -496,21 +496,34 @@ func diffT(ctx context.Context, a, b *Tree, δZTC SetOid) (δ map[Key]ΔValue, e
 		}
 
 		// merge δ <- δc
-		for k, v := range δc {
-			vprev, already := δ[k]
+		for k, δv1 := range δc {
+			δv2, already := δ[k]
 			if !already {
-				δ[k] = v
+				δ[k] = δv1
+				continue
+			}
+
+			// both δ and δc has [k] - it can be that key
+			// entry migrated from one bucket into another.
+			if !( (δv2.New == VDEL && δv1.Old == VDEL) ||
+			      (δv2.Old == VDEL && δv1.New == VDEL) ) {
+				return nil, fmt.Errorf("BUG or btree corrupt: [%v] has " +
+						"duplicate entries: %v, %v", k, δv1, δv2)
+			}
+
+			δv := ΔValue{}
+			if δv1.New == VDEL {
+				δv.Old = δv1.Old
+				δv.New = δv2.New
 			} else {
-				// both δ and δc has [k] - it can be that key
-				// entry migrated from one bucket into another.
-				if (vprev == VDEL && v == VDEL) || (vprev != VDEL && v != VDEL) {
-					return nil, fmt.Errorf("BUG or btree corrupt: [%v] has " +
-							"duplicate entries: %v, %v", k, vprev, v)
-				}
-				delete(δ, k)	// FIXME does not notice change in v on reflow
+				δv.Old = δv2.Old
+				δv.New = δv1.New
 			}
+
+			δ[k] = δv
 		}
 
+/*
 		// merge Tkdel <- δc
 		for k, v := range δc {
 			if v == VDEL {
@@ -519,6 +532,7 @@ func diffT(ctx context.Context, a, b *Tree, δZTC SetOid) (δ map[Key]ΔValue, e
 				delete(Tkdel, k)
 			}
 		}
+*/
 
 		// XXX process keys from δ outside of already tracked nodes
 		// XXX only deleted keys - no - delete can be from untracked
@@ -557,7 +571,7 @@ func diffB(ctx context.Context, a, b *Bucket) (δ map[Key]ΔValue, err error) {
 	//fmt.Println("> diffB", a.POid())
 	//defer fmt.Println("< diffB")
 
-	δ   = map[Key]Value{}
+	δ   = map[Key]ΔValue{}
 	//fmt.Println("av:", av)
 	//fmt.Println("bv:", bv)