fix prospective-parachains tests

Author: alindima

polkadot/node/core/prospective-parachains/src/fragment_chain/mod.rs

@@ -32,7 +32,7 @@
 //! The best chain contains all the candidates pending availability and a subsequent chain
 //! of candidates that have reached the backing quorum and are better than any other backable forks
 //! according to the fork selection rule (more on this rule later). It has a length of size at most
-//! `max_candidate_depth + 1`.
+//! `num_of_pending_candidates + num_of_assigned_cores_for_para`.
 //!
 //! The unconnected storage keeps a record of seconded/backable candidates that may be
 //! added to the best chain in the future.
@@ -100,13 +100,10 @@
 //! bounded. This means that higher-level code needs to be selective about limiting the amount of
 //! candidates that are considered.
 //!
-//! Practically speaking, the collator-protocol will not allow more than `max_candidate_depth + 1`
-//! collations to be fetched at a relay parent and statement-distribution will not allow more than
-//! `max_candidate_depth + 1` seconded candidates at a relay parent per each validator in the
-//! backing group. Considering the `allowed_ancestry_len` configuration value, the number of
-//! candidates in a `FragmentChain` (including its unconnected storage) should not exceed:
-//!
-//! `allowed_ancestry_len * (max_candidate_depth + 1) * backing_group_size`.
+//! Practically speaking, the collator-protocol will limit the number of fetched collations per
+//! core, to the number of claim queue assignments for the paraid on that core.
+//! Statement-distribution will not allow more than `scheduler_params.lookahead` seconded candidates
+//! at a relay parent per each validator in the backing group.
 //!
 //! The code in this module is not designed for speed or efficiency, but conceptual simplicity.
 //! Our assumption is that the amount of candidates and parachains we consider will be reasonably
@@ -515,6 +512,8 @@ impl Scope {
 			}
 		}
 
+		println!("ALIN: {max_backable_len}");
+
 		Ok(Scope {
 			relay_parent,
 			base_constraints,
@@ -1182,7 +1181,7 @@ impl FragmentChain {
 		let Some(mut earliest_rp) = self.earliest_relay_parent() else { return };
 
 		loop {
-			if self.best_chain.chain.len() > self.scope.max_backable_len {
+			if self.best_chain.chain.len() >= self.scope.max_backable_len {
 				break;
 			}
 

polkadot/node/core/prospective-parachains/src/fragment_chain/tests.rs

@@ -115,7 +115,7 @@ fn scope_rejects_ancestors_that_skip_blocks() {
 		storage_root: Hash::repeat_byte(69),
 	}];
 
-	let max_depth = 2;
+	let max_depth = 3;
 	let base_constraints = make_constraints(8, vec![8, 9], vec![1, 2, 3].into());
 	let pending_availability = Vec::new();
 
@@ -145,7 +145,7 @@ fn scope_rejects_ancestor_for_0_block() {
 		storage_root: Hash::repeat_byte(69),
 	}];
 
-	let max_depth = 2;
+	let max_depth = 3;
 	let base_constraints = make_constraints(0, vec![], vec![1, 2, 3].into());
 	let pending_availability = Vec::new();
 
@@ -187,7 +187,7 @@ fn scope_only_takes_ancestors_up_to_min() {
 		},
 	];
 
-	let max_depth = 2;
+	let max_depth = 3;
 	let base_constraints = make_constraints(3, vec![2], vec![1, 2, 3].into());
 	let pending_availability = Vec::new();
 
@@ -230,7 +230,7 @@ fn scope_rejects_unordered_ancestors() {
 		},
 	];
 
-	let max_depth = 2;
+	let max_depth = 3;
 	let base_constraints = make_constraints(0, vec![2], vec![1, 2, 3].into());
 	let pending_availability = Vec::new();
 
@@ -496,7 +496,7 @@ fn test_populate_and_check_potential() {
 				relay_parent_z_info.clone(),
 				wrong_constraints.clone(),
 				vec![],
-				4,
+				5,
 				ancestors.clone(),
 			)
 			.unwrap();
@@ -529,7 +529,7 @@ fn test_populate_and_check_potential() {
 
 	// Various depths
 	{
-		// Depth is 0, only allows one candidate, but the others will be kept as potential.
+		// Depth is 0, doesn't allow any candidate, but the others will be kept as potential.
 		let scope = Scope::with_ancestors(
 			relay_parent_z_info.clone(),
 			base_constraints.clone(),
@@ -543,19 +543,40 @@ fn test_populate_and_check_potential() {
 		assert!(chain.can_add_candidate_as_potential(&candidate_b_entry).is_ok());
 		assert!(chain.can_add_candidate_as_potential(&candidate_c_entry).is_ok());
 
+		let chain = populate_chain_from_previous_storage(&scope, &storage);
+		assert!(chain.best_chain_vec().is_empty());
+		assert_eq!(
+			chain.unconnected().map(|c| c.candidate_hash).collect::<HashSet<_>>(),
+			[candidate_a_hash, candidate_b_hash, candidate_c_hash].into_iter().collect()
+		);
+
+		// Depth is 1, only allows one candidate, but the others will be kept as potential.
+		let scope = Scope::with_ancestors(
+			relay_parent_z_info.clone(),
+			base_constraints.clone(),
+			vec![],
+			1,
+			ancestors.clone(),
+		)
+		.unwrap();
+		let chain = FragmentChain::init(scope.clone(), CandidateStorage::default());
+		assert!(chain.can_add_candidate_as_potential(&candidate_a_entry).is_ok());
+		assert!(chain.can_add_candidate_as_potential(&candidate_b_entry).is_ok());
+		assert!(chain.can_add_candidate_as_potential(&candidate_c_entry).is_ok());
+
 		let chain = populate_chain_from_previous_storage(&scope, &storage);
 		assert_eq!(chain.best_chain_vec(), vec![candidate_a_hash]);
 		assert_eq!(
 			chain.unconnected().map(|c| c.candidate_hash).collect::<HashSet<_>>(),
 			[candidate_b_hash, candidate_c_hash].into_iter().collect()
 		);
 
-		// depth is 1, allows two candidates
+		// depth is 2, allows two candidates
 		let scope = Scope::with_ancestors(
 			relay_parent_z_info.clone(),
 			base_constraints.clone(),
 			vec![],
-			1,
+			2,
 			ancestors.clone(),
 		)
 		.unwrap();
@@ -571,8 +592,8 @@ fn test_populate_and_check_potential() {
 			[candidate_c_hash].into_iter().collect()
 		);
 
-		// depth is larger than 2, allows all three candidates
-		for depth in 2..6 {
+		// depth is at least 3, allows all three candidates
+		for depth in 3..6 {
 			let scope = Scope::with_ancestors(
 				relay_parent_z_info.clone(),
 				base_constraints.clone(),
@@ -604,7 +625,7 @@ fn test_populate_and_check_potential() {
 			relay_parent_z_info.clone(),
 			base_constraints.clone(),
 			vec![],
-			4,
+			5,
 			ancestors_without_x,
 		)
 		.unwrap();
@@ -627,7 +648,7 @@ fn test_populate_and_check_potential() {
 			relay_parent_z_info.clone(),
 			base_constraints.clone(),
 			vec![],
-			4,
+			5,
 			vec![],
 		)
 		.unwrap();
@@ -673,7 +694,7 @@ fn test_populate_and_check_potential() {
 			relay_parent_z_info.clone(),
 			base_constraints.clone(),
 			vec![],
-			4,
+			5,
 			ancestors.clone(),
 		)
 		.unwrap();
@@ -715,7 +736,7 @@ fn test_populate_and_check_potential() {
 		relay_parent_z_info.clone(),
 		base_constraints.clone(),
 		vec![],
-		4,
+		5,
 		ancestors.clone(),
 	)
 	.unwrap();
@@ -757,7 +778,7 @@ fn test_populate_and_check_potential() {
 		relay_parent_z_info.clone(),
 		base_constraints.clone(),
 		vec![],
-		4,
+		5,
 		ancestors.clone(),
 	)
 	.unwrap();
@@ -986,7 +1007,7 @@ fn test_populate_and_check_potential() {
 		relay_parent_z_info.clone(),
 		base_constraints.clone(),
 		vec![],
-		2,
+		3,
 		ancestors.clone(),
 	)
 	.unwrap();
@@ -1301,7 +1322,7 @@ fn test_populate_and_check_potential() {
 				relay_parent: relay_parent_z_info.clone(),
 			},
 		],
-		2,
+		0,
 		ancestors.clone(),
 	)
 	.unwrap();
@@ -1326,7 +1347,7 @@ fn test_populate_and_check_potential() {
 		relay_parent_z_info.clone(),
 		base_constraints.clone(),
 		vec![],
-		2,
+		3,
 		ancestors.clone(),
 	)
 	.unwrap();
@@ -1355,7 +1376,7 @@ fn test_populate_and_check_potential() {
 fn test_find_ancestor_path_and_find_backable_chain_empty_best_chain() {
 	let relay_parent = Hash::repeat_byte(1);
 	let required_parent: HeadData = vec![0xff].into();
-	let max_depth = 10;
+	let max_depth = 11;
 
 	// Empty chain
 	let base_constraints = make_constraints(0, vec![0], required_parent.clone());
@@ -1382,7 +1403,7 @@ fn test_find_ancestor_path_and_find_backable_chain() {
 	let para_id = ParaId::from(5u32);
 	let relay_parent = Hash::repeat_byte(1);
 	let required_parent: HeadData = vec![0xff].into();
-	let max_depth = 5;
+	let max_depth = 6;
 	let relay_parent_number = 0;
 	let relay_parent_storage_root = Hash::zero();
 
@@ -1567,7 +1588,7 @@ fn test_find_ancestor_path_and_find_backable_chain() {
 				candidate_hash: candidates[3],
 				relay_parent: relay_parent_info,
 			}],
-			max_depth,
+			max_depth - 1,
 			vec![],
 		)
 		.unwrap();