Add weight of refund extension post_dispatch to the weights of messages pallet (#2089)

* add weight of refund extension post_dispatch to the weights of messages pallet

* fixed tests and removed TODO

* verify runtime overhead weight in integrity tests

* add integrity tests to rialto-parachain runtime

* refactor weights a bit

* refund ext is disabled for Rialto <> Millau bridge

* Update bin/runtime-common/src/integrity.rs

Co-authored-by: Adrian Catangiu <adrian@parity.io>

* Update bin/runtime-common/src/integrity.rs

Co-authored-by: Adrian Catangiu <adrian@parity.io>

* Update modules/relayers/src/weights_ext.rs

Co-authored-by: Adrian Catangiu <adrian@parity.io>

---------

Co-authored-by: Adrian Catangiu <adrian@parity.io>

bridges/modules/relayers/src/weights_ext.rs

@@ -0,0 +1,49 @@
+// Copyright 2019-2021 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common 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.
+
+// Parity Bridges Common 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 Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Weight-related utilities.
+
+use crate::weights::WeightInfo;
+
+use frame_support::pallet_prelude::Weight;
+
+/// Extended weight info.
+pub trait WeightInfoExt: WeightInfo {
+	/// Returns weight, that needs to be added to the pre-dispatch weight of message delivery call,
+	/// if `RefundBridgedParachainMessages` signed extension is deployed at runtime level.
+	fn receive_messages_proof_overhead_from_runtime() -> Weight {
+		Self::slash_and_deregister().max(Self::register_relayer_reward())
+	}
+
+	/// Returns weight, that needs to be added to the pre-dispatch weight of message delivery
+	/// confirmation call, if `RefundBridgedParachainMessages` signed extension is deployed at
+	/// runtime level.
+	fn receive_messages_delivery_proof_overhead_from_runtime() -> Weight {
+		Self::register_relayer_reward()
+	}
+
+	/// Returns weight that we need to deduct from the message delivery call weight that has
+	/// completed successfully.
+	///
+	/// Usually, the weight of `slash_and_deregister` is larger than the weight of the
+	/// `register_relayer_reward`. So if relayer has been rewarded, we want to deduct the difference
+	/// to get the actual post-dispatch weight.
+	fn extra_weight_of_successful_receive_messages_proof_call() -> Weight {
+		Self::slash_and_deregister().saturating_sub(Self::register_relayer_reward())
+	}
+}
+
+impl<T: WeightInfo> WeightInfoExt for T {}