sc_proof_of_time/
lib.rs

1//! Subspace proof of time implementation.
2
3#![feature(let_chains)]
4
5mod slots;
6pub mod source;
7pub mod verifier;
8
9use crate::slots::SlotInfoProducer;
10use crate::source::{PotSlotInfo, PotSlotInfoStream};
11use sc_consensus_slots::{SimpleSlotWorker, SimpleSlotWorkerToSlotWorker, SlotWorker};
12use sp_api::ProvideRuntimeApi;
13use sp_blockchain::HeaderBackend;
14use sp_consensus::{SelectChain, SyncOracle};
15use sp_consensus_slots::{Slot, SlotDuration};
16use sp_consensus_subspace::SubspaceApi;
17use sp_inherents::CreateInherentDataProviders;
18use sp_runtime::traits::Block as BlockT;
19use std::sync::Arc;
20use subspace_core_primitives::pot::PotCheckpoints;
21use subspace_core_primitives::PublicKey;
22use tokio::sync::broadcast::error::RecvError;
23use tracing::{debug, error, info, trace};
24
25pub trait PotSlotWorker<Block>
26where
27    Block: BlockT,
28{
29    /// Called when new proof of time is available for slot.
30    ///
31    /// NOTE: Can be called more than once in case of reorgs to override old slots.
32    fn on_proof(&mut self, slot: Slot, checkpoints: PotCheckpoints);
33}
34
35/// Start a new slot worker.
36///
37/// Every time a new slot is triggered, `worker.on_slot` is called and the future it returns is
38/// polled until completion, unless we are major syncing.
39pub async fn start_slot_worker<Block, Client, SC, Worker, SO, CIDP>(
40    slot_duration: SlotDuration,
41    client: Arc<Client>,
42    select_chain: SC,
43    worker: Worker,
44    sync_oracle: SO,
45    create_inherent_data_providers: CIDP,
46    mut slot_info_stream: PotSlotInfoStream,
47) where
48    Block: BlockT,
49    Client: ProvideRuntimeApi<Block> + HeaderBackend<Block>,
50    Client::Api: SubspaceApi<Block, PublicKey>,
51    SC: SelectChain<Block>,
52    Worker: PotSlotWorker<Block> + SimpleSlotWorker<Block> + Send + Sync,
53    SO: SyncOracle + Send,
54    CIDP: CreateInherentDataProviders<Block, ()> + Send + 'static,
55{
56    let best_hash = client.info().best_hash;
57    let runtime_api = client.runtime_api();
58    let block_authoring_delay = match runtime_api.chain_constants(best_hash) {
59        Ok(chain_constants) => chain_constants.block_authoring_delay(),
60        Err(error) => {
61            error!(%error, "Failed to retrieve chain constants from runtime API");
62            return;
63        }
64    };
65
66    let slot_info_producer = SlotInfoProducer::new(
67        slot_duration.as_duration(),
68        create_inherent_data_providers,
69        select_chain,
70    );
71
72    let mut worker = SimpleSlotWorkerToSlotWorker(worker);
73
74    let mut maybe_last_proven_slot = None;
75
76    loop {
77        let PotSlotInfo { slot, checkpoints } = match slot_info_stream.recv().await {
78            Ok(slot_info) => slot_info,
79            Err(err) => match err {
80                RecvError::Closed => {
81                    info!("No Slot info senders available. Exiting slot worker.");
82                    return;
83                }
84                RecvError::Lagged(skipped_notifications) => {
85                    debug!(
86                        "Slot worker is lagging. Skipped {} slot notification(s)",
87                        skipped_notifications
88                    );
89                    continue;
90                }
91            },
92        };
93        if let Some(last_proven_slot) = maybe_last_proven_slot {
94            if last_proven_slot >= slot {
95                // Already processed
96                continue;
97            }
98        }
99        maybe_last_proven_slot.replace(slot);
100
101        worker.0.on_proof(slot, checkpoints);
102
103        if sync_oracle.is_major_syncing() {
104            debug!(%slot, "Skipping proposal slot due to sync");
105            continue;
106        }
107
108        // Slots that we claim must be `block_authoring_delay` behind the best slot we know of
109        let Some(slot_to_claim) = slot.checked_sub(*block_authoring_delay).map(Slot::from) else {
110            trace!("Skipping very early slot during chain start");
111            continue;
112        };
113
114        if let Some(slot_info) = slot_info_producer.produce_slot_info(slot_to_claim).await {
115            let _ = worker.on_slot(slot_info).await;
116        }
117    }
118}
sc_proof_of_time/lib.rs

sc_proof_of_time/
lib.rs
