Add tasks to publish data onto Serai

coordinator/substrate/src/set_keys.rs

@@ -0,0 +1,88 @@
+use core::future::Future;
+use std::sync::Arc;
+
+use serai_db::{DbTxn, Db};
+
+use serai_client::{primitives::NetworkId, validator_sets::primitives::ValidatorSet, Serai};
+
+use serai_task::ContinuallyRan;
+
+use crate::Keys;
+
+/// Set keys from `Keys` on Serai.
+pub struct SetKeysTask<D: Db> {
+  db: D,
+  serai: Arc<Serai>,
+}
+
+impl<D: Db> SetKeysTask<D> {
+  /// Create a task to publish slash reports onto Serai.
+  pub fn new(db: D, serai: Arc<Serai>) -> Self {
+    Self { db, serai }
+  }
+}
+
+impl<D: Db> ContinuallyRan for SetKeysTask<D> {
+  type Error = String;
+
+  fn run_iteration(&mut self) -> impl Send + Future<Output = Result<bool, Self::Error>> {
+    async move {
+      let mut made_progress = false;
+      for network in serai_client::primitives::NETWORKS {
+        if network == NetworkId::Serai {
+          continue;
+        };
+
+        let mut txn = self.db.txn();
+        let Some((session, keys)) = Keys::take(&mut txn, network) else {
+          // No keys to set
+          continue;
+        };
+
+        let serai =
+          self.serai.as_of_latest_finalized_block().await.map_err(|e| format!("{e:?}"))?;
+        let serai = serai.validator_sets();
+        let current_session = serai.session(network).await.map_err(|e| format!("{e:?}"))?;
+        let current_session = current_session.map(|session| session.0);
+        // Only attempt to set these keys if this isn't a retired session
+        if Some(session.0) < current_session {
+          // Commit the txn to take these keys from the database and not try it again later
+          txn.commit();
+          continue;
+        }
+
+        if Some(session.0) != current_session {
+          // We already checked the current session wasn't greater, and they're not equal
+          assert!(current_session < Some(session.0));
+          // This would mean the Serai node is resyncing and is behind where it prior was
+          Err("have a keys for a session Serai has yet to start".to_string())?;
+        }
+
+        // If this session already has had its keys set, move on
+        if serai
+          .keys(ValidatorSet { network, session })
+          .await
+          .map_err(|e| format!("{e:?}"))?
+          .is_some()
+        {
+          txn.commit();
+          continue;
+        };
+
+        match self.serai.publish(&keys).await {
+          Ok(()) => {
+            txn.commit();
+            made_progress = true;
+          }
+          // This could be specific to this TX (such as an already in mempool error) and it may be
+          // worthwhile to continue iteration with the other pending slash reports. We assume this
+          // error ephemeral and that the latency incurred for this ephemeral error to resolve is
+          // miniscule compared to the window reasonable to set the keys. That makes this a
+          // non-issue.
+          Err(e) => Err(format!("couldn't publish set keys transaction: {e:?}"))?,
+        }
+      }
+      Ok(made_progress)
+    }
+  }
+}