grandpa: pass justification as GrandpaJustification to the rpc module

client/finality-grandpa/rpc/Cargo.toml

@@ -22,6 +22,7 @@ serde_json = "1.0.50"
 log = "0.4.8"
 derive_more = "0.99.2"
 parking_lot = "0.10.0"
+parity-scale-codec = { version = "1.3.0", features = ["derive"] }
 
 [dev-dependencies]
 sp-core = { version = "2.0.0-rc3", path = "../../../primitives/core" }

client/finality-grandpa/rpc/src/notification.rs

@@ -17,7 +17,9 @@
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
 use serde::{Serialize, Deserialize};
+use parity_scale_codec::Encode;
 use sp_runtime::traits::Block as BlockT;
+use sc_finality_grandpa::GrandpaJustification;
 
 /// Justification for a finalized block.
 #[derive(Clone, Serialize, Deserialize)]
@@ -28,11 +30,11 @@ pub struct JustificationNotification<Block: BlockT> {
 	pub justification: Vec<u8>,
 }
 
-impl<Block: BlockT> From<(Block::Header, Vec<u8>)> for JustificationNotification<Block> {
-	fn from(notification: (Block::Header, Vec<u8>)) -> Self {
+impl<Block: BlockT> From<(Block::Header, GrandpaJustification<Block>)> for JustificationNotification<Block> {
+	fn from(notification: (Block::Header, GrandpaJustification<Block>)) -> Self {
 		JustificationNotification {
 			header: notification.0,
-			justification: notification.1,
+			justification: notification.1.encode(),
 		}
 	}
 }

client/finality-grandpa/src/environment.rs

@@ -1148,7 +1148,7 @@ pub(crate) fn finalize_block<BE, Block, Client>(
 		// justifications for transition blocks which will be requested by
 		// syncing clients.
 		let justification = match justification_or_commit {
-			JustificationOrCommit::Justification(justification) => Some(justification.encode()),
+			JustificationOrCommit::Justification(justification) => Some(justification),
 			JustificationOrCommit::Commit((round_number, commit)) => {
 				let mut justification_required =
 					// justification is always required when block that enacts new authorities
@@ -1175,17 +1175,18 @@ pub(crate) fn finalize_block<BE, Block, Client>(
 						commit,
 					)?;
 
-					Some(justification.encode())
+					Some(justification)
 				} else {
 					None
 				}
 			},
 		};
 
-		if let Some(justification) = justification.clone() {
+		// Notify any registered listeners in case we have a justification
+		if let Some(ref justification) = justification {
 			match client.header(BlockId::Hash(hash)) {
 				Ok(Some(header)) => {
-					let notification = (header, justification);
+					let notification = (header, justification.clone());
 					if let Some(sender) = justification_sender {
 						let _ = sender.notify(notification);
 					}
@@ -1195,6 +1196,8 @@ pub(crate) fn finalize_block<BE, Block, Client>(
 			};
 		}
 
+		let justification = justification.map(|j| j.encode());
+
 		debug!(target: "afg", "Finalizing blocks up to ({:?}, {})", number, hash);
 
 		// ideally some handle to a synchronization oracle would be used

client/finality-grandpa/src/justification.rs

@@ -37,7 +37,7 @@ use crate::{Commit, Error};
 ///
 /// This is meant to be stored in the db and passed around the network to other
 /// nodes, and are used by syncing nodes to prove authority set handoffs.
-#[derive(Encode, Decode)]
+#[derive(Clone, Encode, Decode)]
 pub struct GrandpaJustification<Block: BlockT> {
 	round: u64,
 	pub(crate) commit: Commit<Block>,

client/finality-grandpa/src/notification.rs

@@ -22,8 +22,10 @@ use parking_lot::Mutex;
 use sp_runtime::traits::Block as BlockT;
 use sp_utils::mpsc::{tracing_unbounded, TracingUnboundedSender, TracingUnboundedReceiver};
 
+use crate::justification::GrandpaJustification;
+
 /// Justification for a finalized block.
-type JustificationNotification<Block> = (<Block as BlockT>::Header, Vec<u8>);
+type JustificationNotification<Block> = (<Block as BlockT>::Header, GrandpaJustification<Block>);
 
 // Stream of justifications returned when subscribing.
 type JustificationStream<Block> = TracingUnboundedReceiver<JustificationNotification<Block>>;