txn.DBIs method (#14)

mdbx/txn.go

@@ -684,3 +684,24 @@ func (txn *Txn) Sequence(dbi DBI, increment uint64) (uint64, error) {
 	}
 	return uint64(res), nil
 }
+
+// DBIs - return names of all existing DBIs. Doesn't include Main and GC.
+func (txn *Txn) DBIs() ([]string, error) {
+	var res []string
+	root, err := txn.OpenRoot(0)
+	if err != nil {
+		return nil, err
+	}
+	c, err := txn.OpenCursor(root)
+	if err != nil {
+		return nil, err
+	}
+	defer c.Close()
+	for k, _, err := c.Get(nil, nil, First); !IsNotFound(err); k, _, err = c.Get(nil, nil, Next) {
+		if err != nil {
+			return nil, err
+		}
+		res = append(res, string(k))
+	}
+	return res, nil
+}

mdbx/txn_test.go

@@ -974,6 +974,90 @@ func TestTxn_StatOnEmpty(t *testing.T) {
 	}
 }
 
+func TestTxn_DBIs(t *testing.T) {
+	env := setup(t)
+	defer env.Close()
+
+	if err := env.Update(func(txn *Txn) (err error) {
+		_, err = txn.OpenDBISimple("test1", Create|DupSort)
+		if err != nil {
+			return err
+		}
+		_, err = txn.OpenDBISimple("test2", Create)
+		if err != nil {
+			return err
+		}
+		list, err := txn.DBIs()
+		if err != nil {
+			return err
+		}
+		if len(list) != 2 {
+			t.Fatalf("unexpected list of dbi's %+v", list)
+		}
+		if list[0] != "test1" {
+			t.Fatalf("unexpected list of dbi's %+v", list)
+		}
+		if list[1] != "test2" {
+			t.Fatalf("unexpected list of dbi's %+v", list)
+		}
+
+		return nil
+	}); err != nil {
+		t.Errorf("%s", err)
+		return
+	}
+
+	if err := env.View(func(txn *Txn) (err error) {
+		list, err := txn.DBIs()
+		if err != nil {
+			return err
+		}
+
+		if len(list) != 2 {
+			t.Fatalf("unexpected list of dbi's %+v", list)
+		}
+		if list[0] != "test1" {
+			t.Fatalf("unexpected list of dbi's %+v", list)
+		}
+		if list[1] != "test2" {
+			t.Fatalf("unexpected list of dbi's %+v", list)
+		}
+		return nil
+	}); err != nil {
+		t.Errorf("%s", err)
+		return
+	}
+
+	if err := env.Update(func(txn *Txn) (err error) {
+		dbi, err := txn.OpenDBI("test1", 0, nil, nil)
+		if err != nil {
+			return err
+		}
+
+		err = txn.Drop(dbi, true)
+		if err != nil {
+			return err
+		}
+
+		list, err := txn.DBIs()
+		if err != nil {
+			return err
+		}
+
+		if len(list) != 1 {
+			t.Fatalf("unexpected list of dbi's %+v", list)
+		}
+		if list[0] != "test2" {
+			t.Fatalf("unexpected list of dbi's %+v", list)
+		}
+		return nil
+	}); err != nil {
+		t.Errorf("%s", err)
+		return
+	}
+
+}
+
 func TestSequence(t *testing.T) {
 	env := setup(t)
 	path, err := env.Path()