Delay reputation updates (#7214)

* Add futures-timer

* Make cost_or_benefit public

* Update ReportPeer message format

* Add delay to reputation updates (dirtywork)

* Update ReputationAggregator

* Update tests

* Fix flucky tests

* Move reputation to state

* Use the main loop for handling reputation sendings

* Update

* Move reputation to utils

* Update reputation sending

* Fix arguments order

* Update state

* Remove new from state

* Add constant

* Add failing test for delay

* Change mocking approach

* Fix type errors

* Fix comments

* Add message handling to select

* Fix bitfields-distribution tests

* Add docs to reputation aggregator

* Replace .into_base_rep

* Use one REPUTATION_CHANGE_INTERVAL by default

* Add reputation change to statement-distribution

* Update polkadot-availability-bitfield-distribution

* Update futures selecting in subsystems

* Update reputation adding

* Send malicious changes right away without adding to state

* Add reputation to StatementDistributionSubsystem

* Handle reputation in statement distribution

* Add delay test for polkadot-statement-distribution

* Fix collator-protocol tests before applying reputation delay

* Remove into_base_rep

* Add reputation to State

* Fix failed tests

* Add reputation delay

* Update tests

* Add batched network message for peer reporting

* Update approval-distribution tests

* Update bitfield-distribution tests

* Update statement-distribution tests

* Update collator-protocol tests

* Remove levels in matching

* Address clippy errors

* Fix overseer test

* Add a metric for original count of rep changes

* Update Reputation

* Revert "Add a metric for original count of rep changes"

This reverts commit 6c9b0c1ec34491d16e562bdcba8db6b9dcf484db.

* Update node/subsystem-util/src/reputation.rs

Co-authored-by: Vsevolod Stakhov <vsevolod.stakhov@parity.io>

* Remove redundant vec

---------

Co-authored-by: Vsevolod Stakhov <vsevolod.stakhov@parity.io>

polkadot/node/subsystem-util/src/lib.rs

@@ -77,6 +77,8 @@ pub mod database;
 /// tasks, sending messages back.
 pub mod nesting_sender;
 
+pub mod reputation;
+
 mod determine_new_blocks;
 
 #[cfg(test)]

polkadot/node/subsystem-util/src/reputation.rs

@@ -0,0 +1,116 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot 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.
+
+// Polkadot 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 Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+//! A utility abstraction to collect and send reputation changes.
+
+use polkadot_node_network_protocol::{PeerId, UnifiedReputationChange};
+use polkadot_node_subsystem::{
+	messages::{NetworkBridgeTxMessage, ReportPeerMessage},
+	overseer,
+};
+use std::{collections::HashMap, time::Duration};
+
+/// Default delay for sending reputation changes
+pub const REPUTATION_CHANGE_INTERVAL: Duration = Duration::from_secs(30);
+
+type BatchReputationChange = HashMap<PeerId, i32>;
+
+/// Collects reputation changes and sends them in one batch to relieve network channels
+#[derive(Debug, Clone)]
+pub struct ReputationAggregator {
+	send_immediately_if: fn(UnifiedReputationChange) -> bool,
+	by_peer: Option<BatchReputationChange>,
+}
+
+impl Default for ReputationAggregator {
+	fn default() -> Self {
+		Self::new(|rep| matches!(rep, UnifiedReputationChange::Malicious(_)))
+	}
+}
+
+impl ReputationAggregator {
+	/// New ReputationAggregator
+	///
+	/// # Arguments
+	///
+	/// * `send_immediately_if` - A function, takes `UnifiedReputationChange`,
+	/// results shows if we need to send the changes right away.
+	/// By default, it is used for sending `UnifiedReputationChange::Malicious` changes immediately and for testing.
+	pub fn new(send_immediately_if: fn(UnifiedReputationChange) -> bool) -> Self {
+		Self { by_peer: Default::default(), send_immediately_if }
+	}
+
+	/// Sends collected reputation changes in a batch,
+	/// removing them from inner state
+	pub async fn send(
+		&mut self,
+		sender: &mut impl overseer::SubsystemSender<NetworkBridgeTxMessage>,
+	) {
+		if let Some(by_peer) = self.by_peer.take() {
+			sender
+				.send_message(NetworkBridgeTxMessage::ReportPeer(ReportPeerMessage::Batch(by_peer)))
+				.await;
+		}
+	}
+
+	/// Adds reputation change to inner state
+	/// or sends it right away if the change is dangerous
+	pub async fn modify(
+		&mut self,
+		sender: &mut impl overseer::SubsystemSender<NetworkBridgeTxMessage>,
+		peer_id: PeerId,
+		rep: UnifiedReputationChange,
+	) {
+		if (self.send_immediately_if)(rep) {
+			self.single_send(sender, peer_id, rep).await;
+		} else {
+			self.add(peer_id, rep);
+		}
+	}
+
+	async fn single_send(
+		&self,
+		sender: &mut impl overseer::SubsystemSender<NetworkBridgeTxMessage>,
+		peer_id: PeerId,
+		rep: UnifiedReputationChange,
+	) {
+		sender
+			.send_message(NetworkBridgeTxMessage::ReportPeer(ReportPeerMessage::Single(
+				peer_id,
+				rep.into(),
+			)))
+			.await;
+	}
+
+	fn add(&mut self, peer_id: PeerId, rep: UnifiedReputationChange) {
+		if self.by_peer.is_none() {
+			self.by_peer = Some(HashMap::new());
+		}
+		if let Some(ref mut by_peer) = self.by_peer {
+			add_reputation(by_peer, peer_id, rep)
+		}
+	}
+}
+
+/// Add a reputation change to an existing collection.
+pub fn add_reputation(
+	acc: &mut BatchReputationChange,
+	peer_id: PeerId,
+	rep: UnifiedReputationChange,
+) {
+	let cost = rep.cost_or_benefit();
+	acc.entry(peer_id).and_modify(|v| *v = v.saturating_add(cost)).or_insert(cost);
+}