// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
// This file is part of Frontier.
//
// Copyright (c) 2020-2022 Parity Technologies (UK) Ltd.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.

#![warn(unused_crate_dependencies)]

// Substrate
pub use sc_client_db::DatabaseSource;
use sp_runtime::traits::Block as BlockT;

pub mod kv;
#[cfg(feature = "sql")]
pub mod sql;

#[derive(Clone)]
pub enum Backend<Block: BlockT> {
	KeyValue(kv::Backend<Block>),
	#[cfg(feature = "sql")]
	Sql(sql::Backend<Block>),
}