sc_proof_of_time/
lib.rs

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

sc_proof_of_time/
lib.rs
