cumulus_pallet_xcmp_queue/
bridging.rs

1// Copyright (C) Parity Technologies (UK) Ltd.
2// SPDX-License-Identifier: Apache-2.0
3
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at
7//
8// 	http://www.apache.org/licenses/LICENSE-2.0
9//
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15
16use crate::{pallet, OutboundState};
17use cumulus_primitives_core::ParaId;
18use xcm::latest::prelude::*;
19
20/// Adapter implementation for `bp_xcm_bridge_hub_router::XcmChannelStatusProvider` which checks
21/// both `OutboundXcmpStatus` and `InboundXcmpStatus` for defined `Location` if any of those is
22/// suspended.
23pub struct InAndOutXcmpChannelStatusProvider<Runtime>(core::marker::PhantomData<Runtime>);
24impl<Runtime: crate::Config> bp_xcm_bridge_hub_router::XcmChannelStatusProvider
25	for InAndOutXcmpChannelStatusProvider<Runtime>
26{
27	fn is_congested(with: &Location) -> bool {
28		// handle congestion only for a sibling parachain locations.
29		let sibling_para_id: ParaId = match with.unpack() {
30			(_, [Parachain(para_id)]) => (*para_id).into(),
31			_ => return false,
32		};
33
34		// if the inbound channel with recipient is suspended, it means that we are unable to
35		// receive congestion reports from the `with` location. So we assume the pipeline is
36		// congested too.
37		if pallet::Pallet::<Runtime>::is_inbound_channel_suspended(sibling_para_id) {
38			return true
39		}
40
41		// if the outbound channel with recipient is suspended, it means that one of further
42		// queues (e.g. bridge queue between two bridge hubs) is overloaded, so we shall
43		// take larger fee for our outbound messages
44		OutXcmpChannelStatusProvider::<Runtime>::is_congested(with)
45	}
46}
47
48/// Adapter implementation for `bp_xcm_bridge::ChannelStatusProvider` and/or
49/// `bp_xcm_bridge_hub_router::XcmChannelStatusProvider` which checks only `OutboundXcmpStatus`
50/// for defined `Location` if is suspended.
51pub struct OutXcmpChannelStatusProvider<Runtime>(core::marker::PhantomData<Runtime>);
52impl<Runtime: crate::Config> OutXcmpChannelStatusProvider<Runtime> {
53	fn is_congested(with: &Location) -> bool {
54		// handle congestion only for a sibling parachain locations.
55		let sibling_para_id: ParaId = match with.unpack() {
56			(_, [Parachain(para_id)]) => (*para_id).into(),
57			_ => return false,
58		};
59
60		// let's find the channel's state with the sibling parachain,
61		let Some((outbound_state, queued_pages)) =
62			pallet::Pallet::<Runtime>::outbound_channel_state(sibling_para_id)
63		else {
64			return false
65		};
66		// suspended channel => it is congested
67		if outbound_state == OutboundState::Suspended {
68			return true
69		}
70
71		// It takes some time for target parachain to suspend inbound channel with the target BH and
72		// during that we will keep accepting new message delivery transactions. Let's also reject
73		// new deliveries if there are too many "pages" (concatenated XCM messages) in the target BH
74		// -> target parachain queue.
75
76		// If the outbound channel has at least `N` pages enqueued, let's assume it is congested.
77		// Normally, the chain with a few opened HRMP channels, will "send" pages at every block.
78		// Having `N` pages means that for last `N` blocks we either have not sent any messages,
79		// or have sent signals.
80
81		const MAX_QUEUED_PAGES_BEFORE_DEACTIVATION: u16 = 4;
82		if queued_pages > MAX_QUEUED_PAGES_BEFORE_DEACTIVATION {
83			return true
84		}
85
86		false
87	}
88}
89
90impl<Runtime: crate::Config> bp_xcm_bridge_hub_router::XcmChannelStatusProvider
91	for OutXcmpChannelStatusProvider<Runtime>
92{
93	fn is_congested(with: &Location) -> bool {
94		Self::is_congested(with)
95	}
96}
97
98#[cfg(feature = "runtime-benchmarks")]
99pub fn suspend_channel_for_benchmarks<T: crate::Config>(target: ParaId) {
100	pallet::Pallet::<T>::suspend_channel(target)
101}
cumulus_pallet_xcmp_queue/bridging.rs

cumulus_pallet_xcmp_queue/
bridging.rs
