Storing multiple Justifications per block (#7640)

* primitives/runtime: initial changes on supporting multiple Justifications

* primitives/runtime: make Justifications strongly typed

* Encode/decode Justifications

* primitives/runtime: add Justification type

* backend: apply_finality and finalize_block takes a single Justification

* manual-seal: create engine id and let rpc take encoded justification

* backend: skeleton functions for appending justifications

* backend: initial implementation append_justification

Initial implementation of append_justification on the Backend trait, and also remove unused skeleton
functions for append_justificaton on Finaziler trait.
k

* backend: guard against duplicate consensus engine id

* client/db: add check for block finality

* client/api: add append_justification to in_mem db

* client/light: add no-op append_justification

* network: fix decode call for Justification

* network: only send a single Justification in BlockData

* network: minor comment update

* protocol: update field names to distinguish single justification

* client: further field renames to plural

* client: update function names to plural justifications

* client/db: upgrade existing database for new format

* network: remove dependency on grandpa crate

* db: fix check for finalized block

* grandpa: check for multiple grandpa justifications hwne importing

* backend: update Finalizer trait to take multiple Justifications

* db: remove debugging statements in migration code

* manual-seal: update note about engine id

* db: fix check for finalized block

* client: update variable name to reflect it is now plural

* grandpa: fix incorrect empty Justications in test

* primitives: make Justifications opaque to avoid being empty

* network: fix detecting empty Justification

* runtime: doc strings for Justifications functions

* runtime: add into_justifications

* primitives: check for duplicates in when adding to Justifications

* network/test: use real grandpa engine id in test

* client: fix reviewer comments

* primitives: rename Justifications::push to append

* backend: revert changes to Finalizer trait

* backend: revert mark_finalized

* backend: revert changes to finalize_block

* backend: revert finalized_blocks

* db: add a quick early return for performance

* client: minor reviewer comments

* service/test: use local ConsensusEngineId

* network: add link to issue for sending multiple Justifications

* Apply suggestions from code review

Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>

* Apply suggestions from code review

Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>

* network: tweaks to review suggestions

* network: revert change to BlockData for backwards compatibility

* Apply suggestion from code review

Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>

* Apply suggestions from code review

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

* primitives: update doc comment for Justifications

* client/db/upgrade: avoid grandpa crate dependency

* consensus: revert to single Justification for import_justification

* primitives: improve justifications docs

* style cleanups

* use and_then

* client: rename JUSTIFICATIONS db column

* network: revert to using FRNK in network-test

Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>
Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>
Co-authored-by: André Silva <andrerfosilva@gmail.com>

substrate/client/network/test/src/lib.rs

@@ -63,7 +63,7 @@ use sp_core::H256;
 use sc_network::config::ProtocolConfig;
 use sp_runtime::generic::{BlockId, OpaqueDigestItemId};
 use sp_runtime::traits::{Block as BlockT, Header as HeaderT, NumberFor};
-use sp_runtime::Justification;
+use sp_runtime::{Justification, Justifications};
 use substrate_test_runtime_client::{self, AccountKeyring};
 use sc_service::client::Client;
 pub use sc_network::config::EmptyTransactionPool;
@@ -109,7 +109,7 @@ impl<B: BlockT> Verifier<B> for PassThroughVerifier {
 		&mut self,
 		origin: BlockOrigin,
 		header: B::Header,
-		justification: Option<Justification>,
+		justifications: Option<Justifications>,
 		body: Option<Vec<B::Extrinsic>>
 	) -> Result<(BlockImportParams<B, ()>, Option<Vec<(CacheKeyId, Vec<u8>)>>), String> {
 		let maybe_keys = header.digest()
@@ -120,7 +120,7 @@ impl<B: BlockT> Verifier<B> for PassThroughVerifier {
 		let mut import = BlockImportParams::new(origin, header);
 		import.body = body;
 		import.finalized = self.finalized;
-		import.justification = justification;
+		import.justifications = justifications;
 		import.fork_choice = Some(self.fork_choice.clone());
 
 		Ok((import, maybe_keys))
@@ -184,10 +184,10 @@ impl PeersClient {
 		}
 	}
 
-	pub fn justification(&self, block: &BlockId<Block>) -> ClientResult<Option<Justification>> {
+	pub fn justifications(&self, block: &BlockId<Block>) -> ClientResult<Option<Justifications>> {
 		match *self {
-			PeersClient::Full(ref client, ref _backend) => client.justification(block),
-			PeersClient::Light(ref client, ref _backend) => client.justification(block),
+			PeersClient::Full(ref client, ref _backend) => client.justifications(block),
+			PeersClient::Light(ref client, ref _backend) => client.justifications(block),
 		}
 	}
 
@@ -577,11 +577,11 @@ impl<B: BlockT> Verifier<B> for VerifierAdapter<B> {
 		&mut self,
 		origin: BlockOrigin,
 		header: B::Header,
-		justification: Option<Justification>,
+		justifications: Option<Justifications>,
 		body: Option<Vec<B::Extrinsic>>
 	) -> Result<(BlockImportParams<B, ()>, Option<Vec<(CacheKeyId, Vec<u8>)>>), String> {
 		let hash = header.hash();
-		self.verifier.lock().verify(origin, header, justification, body).map_err(|e| {
+		self.verifier.lock().verify(origin, header, justifications, body).map_err(|e| {
 			self.failed_verifications.lock().insert(hash, e.clone());
 			e
 		})