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/db/src/upgrade.rs

@@ -23,17 +23,19 @@ use std::io::{Read, Write, ErrorKind};
 use std::path::{Path, PathBuf};
 
 use sp_runtime::traits::Block as BlockT;
-use crate::utils::DatabaseType;
+use crate::{columns, utils::DatabaseType};
 use kvdb_rocksdb::{Database, DatabaseConfig};
+use codec::Encode;
 
 /// Version file name.
 const VERSION_FILE_NAME: &'static str = "db_version";
 
 /// Current db version.
-const CURRENT_VERSION: u32 = 2;
+const CURRENT_VERSION: u32 = 3;
 
 /// Number of columns in v1.
 const V1_NUM_COLUMNS: u32 = 11;
+const V2_NUM_COLUMNS: u32 = 12;
 
 /// Upgrade database to current version.
 pub fn upgrade_db<Block: BlockT>(db_path: &Path, db_type: DatabaseType) -> sp_blockchain::Result<()> {
@@ -42,7 +44,11 @@ pub fn upgrade_db<Block: BlockT>(db_path: &Path, db_type: DatabaseType) -> sp_bl
 		let db_version = current_version(db_path)?;
 		match db_version {
 			0 => Err(sp_blockchain::Error::Backend(format!("Unsupported database version: {}", db_version)))?,
-			1 => migrate_1_to_2::<Block>(db_path, db_type)?,
+			1 => {
+				migrate_1_to_2::<Block>(db_path, db_type)?;
+				migrate_2_to_3::<Block>(db_path, db_type)?
+			},
+			2 => migrate_2_to_3::<Block>(db_path, db_type)?,
 			CURRENT_VERSION => (),
 			_ => Err(sp_blockchain::Error::Backend(format!("Future database version: {}", db_version)))?,
 		}
@@ -62,6 +68,31 @@ fn migrate_1_to_2<Block: BlockT>(db_path: &Path, _db_type: DatabaseType) -> sp_b
 	db.add_column().map_err(db_err)
 }
 
+/// Migration from version2 to version3:
+/// - The format of the stored Justification changed to support multiple Justifications.
+fn migrate_2_to_3<Block: BlockT>(db_path: &Path, _db_type: DatabaseType) -> sp_blockchain::Result<()> {
+	let db_path = db_path.to_str()
+		.ok_or_else(|| sp_blockchain::Error::Backend("Invalid database path".into()))?;
+	let db_cfg = DatabaseConfig::with_columns(V2_NUM_COLUMNS);
+	let db = Database::open(&db_cfg, db_path).map_err(db_err)?;
+
+	// Get all the keys we need to update
+	let keys: Vec<_> = db.iter(columns::JUSTIFICATIONS).map(|entry| entry.0).collect();
+
+	// Read and update each entry
+	let mut transaction = db.transaction();
+	for key in keys {
+		if let Some(justification) = db.get(columns::JUSTIFICATIONS, &key).map_err(db_err)? {
+			// Tag each Justification with the hardcoded ID for GRANDPA. Avoid the dependency on the GRANDPA crate
+			let justifications = sp_runtime::Justifications::from((*b"FRNK", justification));
+			transaction.put_vec(columns::JUSTIFICATIONS, &key, justifications.encode());
+		}
+	}
+	db.write(transaction).map_err(db_err)?;
+
+	Ok(())
+}
+
 /// Reads current database version from the file at given path.
 /// If the file does not exist returns 0.
 fn current_version(path: &Path) -> sp_blockchain::Result<u32> {
@@ -141,8 +172,8 @@ mod tests {
 	}
 
 	#[test]
-	fn upgrade_from_1_to_2_works() {
-		for version_from_file in &[None, Some(1)] {
+	fn upgrade_to_3_works() {
+		for version_from_file in &[None, Some(1), Some(2)] {
 			let db_dir = tempfile::TempDir::new().unwrap();
 			let db_path = db_dir.path();
 			create_db(db_path, *version_from_file);