cumulus_client_consensus_common/
lib.rs

1// Copyright (C) Parity Technologies (UK) Ltd.
2// This file is part of Cumulus.
3// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
4
5// Cumulus is free software: you can redistribute it and/or modify
6// it under the terms of the GNU General Public License as published by
7// the Free Software Foundation, either version 3 of the License, or
8// (at your option) any later version.
9
10// Cumulus is distributed in the hope that it will be useful,
11// but WITHOUT ANY WARRANTY; without even the implied warranty of
12// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13// GNU General Public License for more details.
14
15// You should have received a copy of the GNU General Public License
16// along with Cumulus. If not, see <https://www.gnu.org/licenses/>.
17
18use codec::Decode;
19use polkadot_primitives::{Block as PBlock, Hash as PHash, Header as PHeader, ValidationCodeHash};
20
21use cumulus_primitives_core::{relay_chain, AbridgedHostConfiguration};
22use cumulus_relay_chain_interface::{RelayChainError, RelayChainInterface};
23
24use sc_client_api::Backend;
25use sc_consensus::{shared_data::SharedData, BlockImport, ImportResult};
26use sp_consensus_slots::Slot;
27
28use sp_runtime::traits::{Block as BlockT, Header as HeaderT};
29use sp_timestamp::Timestamp;
30
31use std::{sync::Arc, time::Duration};
32
33mod level_monitor;
34mod parachain_consensus;
35mod parent_search;
36#[cfg(test)]
37mod tests;
38
39pub use parent_search::*;
40
41pub use cumulus_relay_chain_streams::finalized_heads;
42pub use parachain_consensus::spawn_parachain_consensus_tasks;
43
44use level_monitor::LevelMonitor;
45pub use level_monitor::{LevelLimit, MAX_LEAVES_PER_LEVEL_SENSIBLE_DEFAULT};
46
47pub mod import_queue;
48
49const LOG_TARGET: &str = "consensus::common";
50
51/// Provides the hash of validation code used for authoring/execution of blocks at a given
52/// hash.
53pub trait ValidationCodeHashProvider<Hash> {
54	fn code_hash_at(&self, at: Hash) -> Option<ValidationCodeHash>;
55}
56
57impl<F, Hash> ValidationCodeHashProvider<Hash> for F
58where
59	F: Fn(Hash) -> Option<ValidationCodeHash>,
60{
61	fn code_hash_at(&self, at: Hash) -> Option<ValidationCodeHash> {
62		(self)(at)
63	}
64}
65
66/// The result from building a collation.
67pub struct ParachainCandidate<B> {
68	/// The block that was built for this candidate.
69	pub block: B,
70	/// The proof that was recorded while building the block.
71	pub proof: sp_trie::StorageProof,
72}
73
74/// Parachain specific block import.
75///
76/// Specialized block import for parachains. It supports to delay setting the best block until the
77/// relay chain has included a candidate in its best block. By default the delayed best block
78/// setting is disabled. The block import also monitors the imported blocks and prunes by default if
79/// there are too many blocks at the same height. Too many blocks at the same height can for example
80/// happen if the relay chain is rejecting the parachain blocks in the validation.
81pub struct ParachainBlockImport<Block: BlockT, BI, BE> {
82	inner: BI,
83	monitor: Option<SharedData<LevelMonitor<Block, BE>>>,
84	delayed_best_block: bool,
85}
86
87impl<Block: BlockT, BI, BE: Backend<Block>> ParachainBlockImport<Block, BI, BE> {
88	/// Create a new instance.
89	///
90	/// The number of leaves per level limit is set to `LevelLimit::Default`.
91	pub fn new(inner: BI, backend: Arc<BE>) -> Self {
92		Self::new_with_limit(inner, backend, LevelLimit::Default)
93	}
94
95	/// Create a new instance with an explicit limit to the number of leaves per level.
96	///
97	/// This function alone doesn't enforce the limit on levels for old imported blocks,
98	/// the limit is eventually enforced only when new blocks are imported.
99	pub fn new_with_limit(inner: BI, backend: Arc<BE>, level_leaves_max: LevelLimit) -> Self {
100		let level_limit = match level_leaves_max {
101			LevelLimit::None => None,
102			LevelLimit::Some(limit) => Some(limit),
103			LevelLimit::Default => Some(MAX_LEAVES_PER_LEVEL_SENSIBLE_DEFAULT),
104		};
105
106		let monitor =
107			level_limit.map(|level_limit| SharedData::new(LevelMonitor::new(level_limit, backend)));
108
109		Self { inner, monitor, delayed_best_block: false }
110	}
111
112	/// Create a new instance which delays setting the best block.
113	///
114	/// The number of leaves per level limit is set to `LevelLimit::Default`.
115	pub fn new_with_delayed_best_block(inner: BI, backend: Arc<BE>) -> Self {
116		Self {
117			delayed_best_block: true,
118			..Self::new_with_limit(inner, backend, LevelLimit::Default)
119		}
120	}
121}
122
123impl<Block: BlockT, I: Clone, BE> Clone for ParachainBlockImport<Block, I, BE> {
124	fn clone(&self) -> Self {
125		ParachainBlockImport {
126			inner: self.inner.clone(),
127			monitor: self.monitor.clone(),
128			delayed_best_block: self.delayed_best_block,
129		}
130	}
131}
132
133#[async_trait::async_trait]
134impl<Block, BI, BE> BlockImport<Block> for ParachainBlockImport<Block, BI, BE>
135where
136	Block: BlockT,
137	BI: BlockImport<Block> + Send + Sync,
138	BE: Backend<Block>,
139{
140	type Error = BI::Error;
141
142	async fn check_block(
143		&self,
144		block: sc_consensus::BlockCheckParams<Block>,
145	) -> Result<sc_consensus::ImportResult, Self::Error> {
146		self.inner.check_block(block).await
147	}
148
149	async fn import_block(
150		&self,
151		mut params: sc_consensus::BlockImportParams<Block>,
152	) -> Result<sc_consensus::ImportResult, Self::Error> {
153		// Blocks are stored within the backend by using POST hash.
154		let hash = params.post_hash();
155		let number = *params.header.number();
156
157		if params.with_state() {
158			// Force imported state finality.
159			// Required for warp sync. We assume that preconditions have been
160			// checked properly and we are importing a finalized block with state.
161			params.finalized = true;
162		}
163
164		if self.delayed_best_block {
165			// Best block is determined by the relay chain, or if we are doing the initial sync
166			// we import all blocks as new best.
167			params.fork_choice = Some(sc_consensus::ForkChoiceStrategy::Custom(
168				params.origin == sp_consensus::BlockOrigin::NetworkInitialSync,
169			));
170		}
171
172		let maybe_lock = self.monitor.as_ref().map(|monitor_lock| {
173			let mut monitor = monitor_lock.shared_data_locked();
174			monitor.enforce_limit(number);
175			monitor.release_mutex()
176		});
177
178		let res = self.inner.import_block(params).await?;
179
180		if let (Some(mut monitor_lock), ImportResult::Imported(_)) = (maybe_lock, &res) {
181			let mut monitor = monitor_lock.upgrade();
182			monitor.block_imported(number, hash);
183		}
184
185		Ok(res)
186	}
187}
188
189/// Marker trait denoting a block import type that fits the parachain requirements.
190pub trait ParachainBlockImportMarker {}
191
192impl<B: BlockT, BI, BE> ParachainBlockImportMarker for ParachainBlockImport<B, BI, BE> {}
193
194/// Get the relay slot from a header.
195pub fn get_relay_slot(relay_header: &PHeader) -> Option<Slot> {
196	match sc_consensus_babe::find_pre_digest::<PBlock>(relay_header) {
197		Ok(pre_digest) => Some(pre_digest.slot()),
198		Err(err) => {
199			tracing::error!(
200				target: LOG_TARGET,
201				hash = %relay_header.hash(),
202				?err,
203				"Relay chain block does not contain a BABE pre-digest. This should never happen.",
204			);
205			None
206		},
207	}
208}
209
210/// Get the relay slot and timestamp from a header.
211pub fn get_relay_slot_and_timestamp(
212	relay_header: &PHeader,
213	relay_slot_duration: Duration,
214) -> Option<(Slot, Timestamp)> {
215	get_relay_slot(relay_header).map(|slot| {
216		let t = Timestamp::new(relay_slot_duration.as_millis() as u64 * *slot);
217		(slot, t)
218	})
219}
220
221/// Reads abridged host configuration from the relay chain storage at the given relay parent.
222pub async fn load_abridged_host_configuration(
223	relay_parent: PHash,
224	relay_client: &impl RelayChainInterface,
225) -> Result<Option<AbridgedHostConfiguration>, RelayChainError> {
226	relay_client
227		.get_storage_by_key(relay_parent, relay_chain::well_known_keys::ACTIVE_CONFIG)
228		.await?
229		.map(|bytes| {
230			AbridgedHostConfiguration::decode(&mut &bytes[..])
231				.map_err(RelayChainError::DeserializationError)
232		})
233		.transpose()
234}
cumulus_client_consensus_common/lib.rs

cumulus_client_consensus_common/
lib.rs
