.

wcfs/δbtail_test.go

@@ -391,29 +391,39 @@ func xwalkDFS(ctx context.Context, lo, hi Key, ztree *Tree, bvisit func(*RBucket
 
 }
 
-// XGetKV translates {k -> <oid>} to {k -> ZBlk(oid).data} according to db@at snapshot.
-func XGetKV(db *zodb.DB, at zodb.Tid, kvOid map[Key]Value) map[Key]string {
-	defer exc.Contextf("%s: @%s: get kv %v", db.Storage().URL(), at, kvOid)
+// XGetδKV translates {k -> δ<oid>} to {k -> δ(ZBlk(oid).data)} according to db@at1..at2 snapshots.
+func XGetδKV(db *zodb.DB, at1, at2 zodb.Tid, δkvOid map[Key]ΔValue) map[Key]Δstring {
+	defer exc.Contextf("%s: get δkv %s..%s %v", db.Storage().URL(), at1, at2, δkvOid)
 	X := exc.Raiseif
 
 	txn, ctx := transaction.New(context.Background())
 	defer txn.Abort()
-	zconn, err := db.Open(ctx, &zodb.ConnOptions{At: at}); X(err)
-
-	kv := map[Key]string{}
-	for k, vOid := range kvOid {
-		if vOid == VDEL {
-			kv[k] = DEL
-			continue
+	zconn1, err := db.Open(ctx, &zodb.ConnOptions{At: at1}); X(err)
+	zconn2, err := db.Open(ctx, &zodb.ConnOptions{At: at2}); X(err)
+
+	δkv := map[Key]Δstring{}
+	for k, δvOid := range δkvOid {
+		δkv[k] = Δstring{
+			Old: xzgetBlkData(ctx, zconn1, δvOid.Old),
+			New: xzgetBlkData(ctx, zconn2, δvOid.New),
 		}
+	}
 
-		xv, err := zconn.Get(ctx, vOid); X(err)
-		zv := xv.(zBlk)
-		data, _, err := zv.loadBlkData(ctx); X(err)
-		kv[k] = string(data)
+	return δkv
+}
+
+// xzgetBlkData loads block data from ZBlk object specified by its oid.
+func xzgetBlkData(ctx context.Context, zconn *zodb.Connection, zblkOid zodb.Oid) string {
+	X := exc.Raiseif
+
+	if zblkOid == VDEL {
+		return DEL
 	}
 
-	return kv
+	xblk, err := zconn.Get(ctx, zblkOid); X(err)
+	zblk := xblk.(zBlk)
+	data, _, err := zblk.loadBlkData(ctx); X(err)
+	return string(data)
 }
 
 
@@ -596,8 +606,8 @@ func xverifyΔBTail1(t *testing.T, subj string, db *zodb.DB, treeRoot zodb.Oid,
 
 
 	// δT <- δB
-	δToid := δB.ByRoot[treeRoot]    // {} k -> δoid
-	δT     = XGetKV(db, at2, δToid) // {} k -> ZBlk(oid).data
+	δToid := δB.ByRoot[treeRoot]         // {} k -> δoid
+	δT     = XGetδKV(db, at1,at2, δToid) // {} k -> δ(ZBlk(oid).data)
 
 	// δT must be subset of d12.
 	// changed keys, that are