Add chain-info Subcommand (#11250)

* Add `blockchain-info` Subcommand

* Update comment

* Cleanup

* Cleanup

* Use `sync_run`

* Use `sc_client_db` utility fns instead service backend

* Use service `Backend` builder

* Impl `From<sp_blockchain::Info>`

* Rename to `chain-info`

* fmt

* Copyright year

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Expose `DatabaseParams`

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

substrate/client/cli/src/commands/chain_info_cmd.rs

@@ -0,0 +1,103 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2022 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// 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/>.
+
+use crate::{CliConfiguration, DatabaseParams, PruningParams, Result as CliResult, SharedParams};
+use parity_scale_codec::{Decode, Encode};
+use sc_client_api::{backend::Backend as BackendT, blockchain::HeaderBackend};
+use sp_blockchain::Info;
+use sp_runtime::traits::{Block as BlockT, Header as HeaderT};
+use std::{fmt::Debug, io};
+
+/// The `chain-info` subcommand used to output db meta columns information.
+#[derive(Debug, Clone, clap::Parser)]
+pub struct ChainInfoCmd {
+	#[allow(missing_docs)]
+	#[clap(flatten)]
+	pub pruning_params: PruningParams,
+
+	#[allow(missing_docs)]
+	#[clap(flatten)]
+	pub shared_params: SharedParams,
+
+	#[allow(missing_docs)]
+	#[clap(flatten)]
+	pub database_params: DatabaseParams,
+}
+
+/// Serializable `chain-info` subcommand output.
+#[derive(Clone, Eq, PartialEq, Debug, Encode, Decode, serde::Serialize)]
+struct ChainInfo<B: BlockT> {
+	/// Best block hash.
+	best_hash: B::Hash,
+	/// Best block number.
+	best_number: <<B as BlockT>::Header as HeaderT>::Number,
+	/// Genesis block hash.
+	genesis_hash: B::Hash,
+	/// The head of the finalized chain.
+	finalized_hash: B::Hash,
+	/// Last finalized block number.
+	finalized_number: <<B as BlockT>::Header as HeaderT>::Number,
+}
+
+impl<B: BlockT> From<Info<B>> for ChainInfo<B> {
+	fn from(info: Info<B>) -> Self {
+		ChainInfo::<B> {
+			best_hash: info.best_hash,
+			best_number: info.best_number,
+			genesis_hash: info.genesis_hash,
+			finalized_hash: info.finalized_hash,
+			finalized_number: info.finalized_number,
+		}
+	}
+}
+
+impl ChainInfoCmd {
+	/// Run the `chain-info` subcommand
+	pub fn run<B>(&self, config: &sc_service::Configuration) -> CliResult<()>
+	where
+		B: BlockT,
+	{
+		let db_config = sc_client_db::DatabaseSettings {
+			state_cache_size: config.state_cache_size,
+			state_cache_child_ratio: config.state_cache_child_ratio.map(|v| (v, 100)),
+			state_pruning: config.state_pruning.clone(),
+			source: config.database.clone(),
+			keep_blocks: config.keep_blocks.clone(),
+		};
+		let backend = sc_service::new_db_backend::<B>(db_config)?;
+		let info: ChainInfo<B> = backend.blockchain().info().into();
+		let mut out = io::stdout();
+		serde_json::to_writer_pretty(&mut out, &info)
+			.map_err(|e| format!("Error writing JSON: {}", e))?;
+		Ok(())
+	}
+}
+
+impl CliConfiguration for ChainInfoCmd {
+	fn shared_params(&self) -> &SharedParams {
+		&self.shared_params
+	}
+
+	fn pruning_params(&self) -> Option<&PruningParams> {
+		Some(&self.pruning_params)
+	}
+
+	fn database_params(&self) -> Option<&DatabaseParams> {
+		Some(&self.database_params)
+	}
+}

substrate/client/cli/src/commands/mod.rs

@@ -16,6 +16,7 @@
 // You should have received a copy of the GNU General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 mod build_spec_cmd;
+mod chain_info_cmd;
 mod check_block_cmd;
 mod export_blocks_cmd;
 mod export_state_cmd;
@@ -35,7 +36,7 @@ mod vanity;
 mod verify;
 
 pub use self::{
-	build_spec_cmd::BuildSpecCmd, check_block_cmd::CheckBlockCmd,
+	build_spec_cmd::BuildSpecCmd, chain_info_cmd::ChainInfoCmd, check_block_cmd::CheckBlockCmd,
 	export_blocks_cmd::ExportBlocksCmd, export_state_cmd::ExportStateCmd, generate::GenerateCmd,
 	generate_node_key::GenerateNodeKeyCmd, import_blocks_cmd::ImportBlocksCmd,
 	insert_key::InsertKeyCmd, inspect_key::InspectKeyCmd, inspect_node_key::InspectNodeKeyCmd,