BABE's revert procedure (#11022)

* First rough draft for BABE revert * Proper babe revert test * Cleanup * Test trivial cleanup * Fix to make clippy happy * Check polkadot companion * Check cumulus companion * Remove babe's blocks weight on revert * Handle "empty" blockchain edge case * Run companions * Simplify the filter predicate * Saturating sub is not required * Run pipeline * Run pipeline again...
2026-04-27 04:37:57 +00:00 · 2022-03-24 09:51:55 +01:00
parent 208be86934
commit c534e00ffc
7 changed files with 314 additions and 22 deletions
@@ -735,6 +735,88 @@ fn importing_block_one_sets_genesis_epoch() {
 	assert_eq!(epoch_for_second_block, genesis_epoch);
 }

+#[test]
+fn revert_prunes_epoch_changes_and_removes_weights() {
+	let mut net = BabeTestNet::new(1);
+
+	let peer = net.peer(0);
+	let data = peer.data.as_ref().expect("babe link set up during initialization");
+
+	let client = peer.client().as_client();
+	let backend = peer.client().as_backend();
+	let mut block_import = data.block_import.lock().take().expect("import set up during init");
+	let epoch_changes = data.link.epoch_changes.clone();
+
+	let mut proposer_factory = DummyFactory {
+		client: client.clone(),
+		config: data.link.config.clone(),
+		epoch_changes: data.link.epoch_changes.clone(),
+		mutator: Arc::new(|_, _| ()),
+	};
+
+	let mut propose_and_import_blocks_wrap = |parent_id, n| {
+		propose_and_import_blocks(&client, &mut proposer_factory, &mut block_import, parent_id, n)
+	};
+
+	// Test scenario.
+	// Information for epoch 19 is produced on three different forks at block #13.
+	// One branch starts before the revert point (epoch data should be maintained).
+	// One branch starts after the revert point (epoch data should be removed).
+	//
+	//                        *----------------- F(#13) --#18                  < fork #2
+	//                       /
+	// A(#1) ---- B(#7) ----#8----+-----#12----- C(#13) ---- D(#19) ------#21  < canon
+	//   \                        ^       \
+	//    \                    revert      *---- G(#13) ---- H(#19) ---#20     < fork #3
+	//     \                   to #10
+	//      *-----E(#7)---#11                                          < fork #1
+	let canon = propose_and_import_blocks_wrap(BlockId::Number(0), 21);
+	let fork1 = propose_and_import_blocks_wrap(BlockId::Hash(canon[0]), 10);
+	let fork2 = propose_and_import_blocks_wrap(BlockId::Hash(canon[7]), 10);
+	let fork3 = propose_and_import_blocks_wrap(BlockId::Hash(canon[11]), 8);
+
+	// We should be tracking a total of 9 epochs in the fork tree
+	assert_eq!(epoch_changes.shared_data().tree().iter().count(), 8);
+	// And only one root
+	assert_eq!(epoch_changes.shared_data().tree().roots().count(), 1);
+
+	// Revert canon chain to block #10 (best(21) - 11)
+	revert(client.clone(), backend, 11).expect("revert should work for baked test scenario");
+
+	// Load and check epoch changes.
+
+	let actual_nodes = aux_schema::load_epoch_changes::<Block, TestClient>(
+		&*client,
+		data.link.config.genesis_config(),
+	)
+	.expect("load epoch changes")
+	.shared_data()
+	.tree()
+	.iter()
+	.map(|(h, _, _)| *h)
+	.collect::<Vec<_>>();
+
+	let expected_nodes = vec![
+		canon[0], // A
+		canon[6], // B
+		fork2[4], // F
+		fork1[5], // E
+	];
+
+	assert_eq!(actual_nodes, expected_nodes);
+
+	let weight_data_check = |hashes: &[Hash], expected: bool| {
+		hashes.iter().all(|hash| {
+			aux_schema::load_block_weight(&*client, hash).unwrap().is_some() == expected
+		})
+	};
+	assert!(weight_data_check(&canon[..10], true));
+	assert!(weight_data_check(&canon[10..], false));
+	assert!(weight_data_check(&fork1, true));
+	assert!(weight_data_check(&fork2, true));
+	assert!(weight_data_check(&fork3, false));
+}
+
 #[test]
 fn importing_epoch_change_block_prunes_tree() {
 	let mut net = BabeTestNet::new(1);