note future changes when importing block

substrate/core/finality-grandpa/src/authorities.rs

@@ -16,23 +16,33 @@
 
 //! Utilities for dealing with authorities, authority sets, and handoffs.
 
+use parking_lot::RwLock;
 use substrate_primitives::AuthorityId;
+
+use std::cmp::Ord;
 use std::ops::Add;
+use std::sync::Arc;
 
 /// A shared authority set.
 pub(crate) struct SharedAuthoritySet<H, N> {
-	inner: RwLock<AuthoritySet<H, N>>,
+	inner: Arc<RwLock<AuthoritySet<H, N>>>,
+}
+
+impl<H, N> Clone for SharedAuthoritySet<H, N> {
+	fn clone(&self) -> Self {
+		SharedAuthoritySet { inner: self.inner.clone() }
+	}
 }
 
 impl<H, N> SharedAuthoritySet<H, N> {
 	/// The genesis authority set.
-	pub(crate) fn genesis(initial: Vec<(AuthorityId, usize)>) -> Self {
+	pub(crate) fn genesis(initial: Vec<(AuthorityId, u64)>) -> Self {
 		SharedAuthoritySet {
-			inner: RwLock::new(AuthoritySet {
+			inner: Arc::new(RwLock::new(AuthoritySet {
 				current_authorities: initial,
 				set_id: 0,
 				pending_changes: Vec::new(),
-			})
+			}))
 		}
 	}
 
@@ -42,33 +52,35 @@ impl<H, N> SharedAuthoritySet<H, N> {
 	{
 		f(&*self.inner.read())
 	}
+}
 
-impl<H, N: Add + Clone> SharedAuthoritySet<H, N> {
+impl<H, N: Add<Output=N> + Ord + Clone> SharedAuthoritySet<H, N> {
 	/// Note an upcoming pending transition.
 	pub(crate) fn add_pending_change(&self, pending: PendingChange<H, N>) {
-		let idx = self.pending_changes
-			.binary_search_by_key(|change| change.effective_number())
+		let mut inner = self.inner.write();
+		let idx = inner.pending_changes
+			.binary_search_by_key(&pending.effective_number(), |change| change.effective_number())
 			.unwrap_or_else(|i| i);
 
-		self.pending_changes.insert(idx);
+		inner.pending_changes.insert(idx, pending);
 	}
 
 	/// Get the earliest limit-block number, if any.
-	pub(crate) fn current_limit(&self) -> Option<&N> {
-		self.pending_changes.get(0).map(|change| &change.effective_number());
+	pub(crate) fn current_limit(&self) -> Option<N> {
+		self.inner.read().pending_changes.get(0).map(|change| change.effective_number().clone())
 	}
 }
 
 impl<H, N> From<AuthoritySet<H, N>> for SharedAuthoritySet<H, N> {
 	fn from(set: AuthoritySet<H, N>) -> Self {
-		SharedAuthoritySet { inner: RwLock::new(set) }
+		SharedAuthoritySet { inner: Arc::new(RwLock::new(set)) }
 	}
 }
 
 /// A set of authorities.
 #[derive(Encode, Decode)]
 pub(crate) struct AuthoritySet<H, N> {
-	current_authorities: Vec<(AuthorityId, usize)>,
+	current_authorities: Vec<(AuthorityId, u64)>,
 	set_id: u64,
 	pending_changes: Vec<PendingChange<H, N>>,
 }
@@ -80,7 +92,7 @@ pub(crate) struct AuthoritySet<H, N> {
 #[derive(Encode, Decode)]
 pub(crate) struct PendingChange<H, N> {
 	/// The new authorities and weights to apply.
-	pub(crate) next_authorities: Vec<(AuthorityId, usize)>,
+	pub(crate) next_authorities: Vec<(AuthorityId, u64)>,
 	/// How deep in the finalized chain the announcing block must be
 	/// before the change is applied.
 	pub(crate) finalization_depth: N,
@@ -90,9 +102,9 @@ pub(crate) struct PendingChange<H, N> {
 	pub(crate) canon_hash: H,
 }
 
-impl<H, N: Add + Clone> PendingChange<H, N> {
+impl<H, N: Add<Output=N> + Clone> PendingChange<H, N> {
 	/// Returns the effective number.
 	fn effective_number(&self) -> N {
-		self.canon_height + self.finalization_depth
+		self.canon_height.clone() + self.finalization_depth.clone()
 	}
 }