Remove ServiceBuilderCommand and implement the chain ops as standalone functions instead. (#6543)

* :)

* Slight tidy

* Remove ServiceBuilderCommand

* Remove whitespace

* Keep task manager alive for check_block/import_blocks

* Pass task_manager to run_until_exit

* Make task_manager in run_until_exit and make subcommands async

* Change the async_run fn to return a future and task manager

* async_run should take a result fn

* Apply suggestions from code review

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

* Fix spaces in export_raw_state

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

substrate/client/service/src/chain_ops/check_block.rs

@@ -0,0 +1,51 @@
+// Copyright 2017-2020 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate 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.
+
+// Substrate 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 Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+use crate::error::Error;
+use futures::{future, prelude::*};
+use sp_runtime::traits::Block as BlockT;
+use sp_runtime::generic::BlockId;
+use codec::Encode;
+use sp_consensus::import_queue::ImportQueue;
+use sc_client_api::{BlockBackend, UsageProvider};
+
+use std::pin::Pin;
+use std::sync::Arc;
+use crate::chain_ops::import_blocks;
+
+/// Re-validate known block.
+pub fn check_block<B, IQ, C>(
+	client: Arc<C>,
+	import_queue: IQ,
+	block_id: BlockId<B>
+) -> Pin<Box<dyn Future<Output = Result<(), Error>> + Send>>
+where
+	C: BlockBackend<B> + UsageProvider<B> + Send + Sync + 'static,
+	B: BlockT + for<'de> serde::Deserialize<'de>,
+	IQ: ImportQueue<B> + 'static,
+{
+	match client.block(&block_id) {
+		Ok(Some(block)) => {
+			let mut buf = Vec::new();
+			1u64.encode_to(&mut buf);
+			block.encode_to(&mut buf);
+			let reader = std::io::Cursor::new(buf);
+			import_blocks(client, import_queue, reader, true, true)
+		}
+		Ok(None) => Box::pin(future::err("Unknown block".into())),
+		Err(e) => Box::pin(future::err(format!("Error reading block: {:?}", e).into())),
+	}
+}