change: move data epoch offset calculation out of data sources

demo/node/src/tests/inherent_data_tests.rs

@@ -43,7 +43,7 @@ async fn block_proposal_cidp_should_be_created_correctly() {
 
 	let inherent_data_providers = ProposalCIDP::new(
 		test_create_inherent_data_config(),
-		TestApi::new(ScEpochNumber(2))
+		TestApi::new(ScEpochNumber(20))
 			.with_headers([(mock_header().hash(), mock_header())])
 			.with_pariticipation_data(vec![(past_block_slot(), past_block_author())])
 			.into(),
@@ -124,7 +124,7 @@ async fn block_verification_cidp_should_be_created_correctly() {
 
 	let verifier_cidp = VerifierCIDP::new(
 		create_inherent_data_config.clone(),
-		TestApi::new(ScEpochNumber(2))
+		TestApi::new(ScEpochNumber(20))
 			.with_pariticipation_data(vec![(past_block_slot(), past_block_author())])
 			.into(),
 		Arc::new(mc_hash_data_source),

toolkit/committee-selection/authority-selection-inherents/src/ariadne_inherent_data_provider.rs

@@ -62,28 +62,30 @@ impl AriadneInherentDataProvider {
 			timestamp_millis,
 		)?;
 
-		let data_epoch = data_source.data_epoch(for_mc_epoch).await?;
+		let data_epoch = offset_data_epoch(&for_mc_epoch).map_err(|offset| {
+			InherentProviderCreationError::McEpochOffsetError(offset, for_mc_epoch)
+		})?;
+
 		// We could accept mc_reference at last slot of data_epoch, but calculations are much easier like that.
 		// Additionally, in current implementation, the inequality below is always true, thus there is no need to make it more accurate.
 		let scripts = client.runtime_api().get_main_chain_scripts(parent_hash)?;
 		if data_epoch < mc_reference_epoch {
-			Ok(AriadneInherentDataProvider::from_mc_data(data_source, for_mc_epoch, scripts)
-				.await?)
+			Ok(AriadneInherentDataProvider::from_mc_data(data_source, data_epoch, scripts).await?)
 		} else {
 			Ok(AriadneInherentDataProvider { data: None })
 		}
 	}
 
 	async fn from_mc_data(
 		candidate_data_source: &(dyn AuthoritySelectionDataSource + Send + Sync),
-		for_epoch: McEpochNumber,
+		data_epoch: McEpochNumber,
 		scripts: MainChainScripts,
 	) -> Result<Self, InherentProviderCreationError> {
 		use crate::authority_selection_inputs::authority_selection_inputs_from_mc_data;
 
 		Ok(Self {
 			data: Some(
-				authority_selection_inputs_from_mc_data(candidate_data_source, for_epoch, scripts)
+				authority_selection_inputs_from_mc_data(candidate_data_source, data_epoch, scripts)
 					.await?,
 			),
 		})
@@ -97,6 +99,10 @@ pub enum InherentProviderCreationError {
 	/// Couldn't convert timestamp to main chain epoch.
 	#[error("Couldn't convert timestamp to main chain epoch: {0}")]
 	McEpochDerivationError(#[from] sidechain_domain::mainchain_epoch::EpochDerivationError),
+	#[error(
+		"Could not apply data offset of {0} to MC epoch {1:?} for authority selection; this is caused either by a node misconfiguration or a bug."
+	)]
+	McEpochOffsetError(u32, McEpochNumber),
 	/// Runtime API call failed.
 	#[error("Runtime API call failed: {0}")]
 	ApiError(#[from] sp_api::ApiError),

toolkit/committee-selection/authority-selection-inherents/src/authority_selection_inputs.rs

@@ -50,7 +50,6 @@ pub struct AriadneParameters {
 #[async_trait::async_trait]
 pub trait AuthoritySelectionDataSource {
 	/// Returns D-parameter and list of permissioned candidates that is effective for the given epoch.
-	/// The data from the latest block of `data_epoch(epoch)` will be used if available, otherwise returns data at the latest block of the chain.
 	async fn get_ariadne_parameters(
 		&self,
 		epoch_number: McEpochNumber,
@@ -59,7 +58,6 @@ pub trait AuthoritySelectionDataSource {
 	) -> Result<AriadneParameters, Box<dyn std::error::Error + Send + Sync>>;
 
 	/// Returns the list of registrations that is effective for the given epoch.
-	/// The data from the latest block of `data_epoch(epoch)` will be used if available, otherwise returns data at the latest block of the chain.
 	/// Each item is a list of one candidate registrations.
 	async fn get_candidates(
 		&self,
@@ -72,37 +70,24 @@ pub trait AuthoritySelectionDataSource {
 		&self,
 		epoch: McEpochNumber,
 	) -> Result<Option<EpochNonce>, Box<dyn std::error::Error + Send + Sync>>;
-
-	///
-	/// # Arguments
-	///
-	/// * `for_epoch`: main chain epoch number during which candidate data is meant to be used
-	///
-	/// returns: Result<McEpochNumber, Box<dyn std::error::Error + Send + Sync>> - data source methods called with `for_epoch` will query only for data which was stored on main chain in the returned epoch or earlier
-	///
-	///
-	async fn data_epoch(
-		&self,
-		for_epoch: McEpochNumber,
-	) -> Result<McEpochNumber, Box<dyn std::error::Error + Send + Sync>>;
 }
 
 #[cfg(feature = "std")]
 pub(crate) async fn authority_selection_inputs_from_mc_data(
 	candidate_data_source: &(dyn AuthoritySelectionDataSource + Send + Sync),
-	for_epoch: McEpochNumber,
+	data_epoch: McEpochNumber,
 	scripts: sp_session_validator_management::MainChainScripts,
 ) -> Result<AuthoritySelectionInputs, AuthoritySelectionInputsCreationError> {
 	let ariadne_parameters_response = candidate_data_source
 		.get_ariadne_parameters(
-			for_epoch,
+			data_epoch,
 			scripts.d_parameter_policy_id.clone(),
 			scripts.permissioned_candidates_policy_id.clone(),
 		)
 		.await
 		.map_err(|err| {
 			AuthoritySelectionInputsCreationError::AriadneParametersQuery(
-				for_epoch,
+				data_epoch,
 				scripts.d_parameter_policy_id.clone(),
 				scripts.permissioned_candidates_policy_id.clone(),
 				err,
@@ -115,7 +100,7 @@ pub(crate) async fn authority_selection_inputs_from_mc_data(
 		None if no_permissioned_candidates_expected => Vec::new(),
 		None => {
 			return Err(AuthoritySelectionInputsCreationError::AriadneParametersQuery(
-				for_epoch,
+				data_epoch,
 				scripts.d_parameter_policy_id,
 				scripts.permissioned_candidates_policy_id,
 				("Expected Data Not Found: Permissioned Candidates List".to_string()).into(),
@@ -125,19 +110,19 @@ pub(crate) async fn authority_selection_inputs_from_mc_data(
 	};
 
 	let registered_candidates: Vec<CandidateRegistrations> = candidate_data_source
-		.get_candidates(for_epoch, scripts.committee_candidate_address.clone())
+		.get_candidates(data_epoch, scripts.committee_candidate_address.clone())
 		.await
 		.map_err(|err| {
 			AuthoritySelectionInputsCreationError::GetCandidatesQuery(
-				for_epoch,
+				data_epoch,
 				scripts.committee_candidate_address.to_string(),
 				err,
 			)
 		})?;
-	let epoch_nonce_response = candidate_data_source
-		.get_epoch_nonce(for_epoch)
-		.await
-		.map_err(|err| AuthoritySelectionInputsCreationError::GetEpochNonceQuery(for_epoch, err))?;
+	let epoch_nonce_response =
+		candidate_data_source.get_epoch_nonce(data_epoch).await.map_err(|err| {
+			AuthoritySelectionInputsCreationError::GetEpochNonceQuery(data_epoch, err)
+		})?;
 	let epoch_nonce = epoch_nonce_response.unwrap_or(EpochNonce(vec![]));
 
 	Ok(AuthoritySelectionInputs {

toolkit/committee-selection/authority-selection-inherents/src/mock.rs

@@ -20,7 +20,7 @@ impl Default for MockAuthoritySelectionDataSource {
 	fn default() -> Self {
 		Self {
 			candidates: vec![vec![], vec![]],
-			permissioned_candidates: vec![Some(vec![]), Some(vec![])],
+			permissioned_candidates: vec![Some(vec![]), Some(vec![]), Some(vec![])],
 			num_permissioned_candidates: 3,
 		}
 	}
@@ -80,11 +80,4 @@ impl AuthoritySelectionDataSource for MockAuthoritySelectionDataSource {
 	) -> Result<Option<EpochNonce>, Box<dyn std::error::Error + Send + Sync>> {
 		Ok(Some(EpochNonce(vec![42u8])))
 	}
-
-	async fn data_epoch(
-		&self,
-		for_epoch: McEpochNumber,
-	) -> Result<McEpochNumber, Box<dyn std::error::Error + Send + Sync>> {
-		Ok(for_epoch)
-	}
 }

toolkit/data-sources/db-sync/src/candidates/cached.rs

@@ -71,13 +71,6 @@ impl AuthoritySelectionDataSource for CandidateDataSourceCached {
 	) -> Result<Option<EpochNonce>, Box<dyn std::error::Error + Send + Sync>> {
 		self.inner.get_epoch_nonce(epoch).await
 	}
-
-	async fn data_epoch(
-		&self,
-		for_epoch: McEpochNumber,
-	) -> Result<McEpochNumber, Box<dyn std::error::Error + Send + Sync>> {
-		self.inner.data_epoch(for_epoch).await
-	}
 }
 
 #[derive(Debug, Clone, Deserialize)]
@@ -176,9 +169,8 @@ impl CandidateDataSourceCached {
 
 	async fn can_use_caching_for_request(
 		&self,
-		request_epoch: McEpochNumber,
+		data_epoch: McEpochNumber,
 	) -> Result<bool, Box<dyn std::error::Error + Send + Sync>> {
-		let data_epoch = self.inner.data_epoch(request_epoch).await?;
 		if let Ok(stable_epoch) = self.highest_seen_stable_epoch.lock() {
 			if stable_epoch.map_or(false, |stable_epoch| stable_epoch >= data_epoch) {
 				return Ok(true);

toolkit/data-sources/db-sync/src/candidates/mod.rs

@@ -61,7 +61,7 @@ impl AuthoritySelectionDataSource for CandidatesDataSourceImpl {
 			d_parameter_policy: PolicyId,
 			permissioned_candidate_policy: PolicyId
 	) -> Result<AriadneParameters, Box<dyn std::error::Error + Send + Sync>> {
-		let epoch = EpochNumber::from(self.get_epoch_of_data_storage(epoch)?);
+		let epoch = EpochNumber::from(epoch);
 		let d_parameter_asset = Asset::new(d_parameter_policy);
 		let permissioned_candidate_asset = Asset::new(permissioned_candidate_policy);
 
@@ -97,7 +97,7 @@ impl AuthoritySelectionDataSource for CandidatesDataSourceImpl {
 			epoch: McEpochNumber,
 			committee_candidate_address: MainchainAddress
 	)-> Result<Vec<CandidateRegistrations>, Box<dyn std::error::Error + Send + Sync>> {
-		let epoch = EpochNumber::from(self.get_epoch_of_data_storage(epoch)?);
+		let epoch = EpochNumber::from(epoch);
 		let candidates = self.get_registered_candidates(epoch, committee_candidate_address).await?;
 		let stake_map = Self::make_stake_map(db_model::get_stake_distribution(&self.pool, epoch).await?);
 		Ok(Self::group_candidates_by_mc_pub_key(candidates).into_iter().map(|(mainchain_pub_key, candidate_registrations)| {
@@ -110,14 +110,9 @@ impl AuthoritySelectionDataSource for CandidatesDataSourceImpl {
 	}
 
 	async fn get_epoch_nonce(&self, epoch: McEpochNumber) -> Result<Option<EpochNonce>, Box<dyn std::error::Error + Send + Sync>> {
-		let epoch = self.get_epoch_of_data_storage(epoch)?;
 		let nonce = db_model::get_epoch_nonce(&self.pool, EpochNumber(epoch.0)).await?;
 		Ok(nonce.map(|n| EpochNonce(n.0)))
 	}
-
-	async fn data_epoch(&self, for_epoch: McEpochNumber) -> Result<McEpochNumber, Box<dyn std::error::Error + Send + Sync>> {
-		self.get_epoch_of_data_storage(for_epoch)
-	}
 });
 
 impl CandidatesDataSourceImpl {
@@ -310,17 +305,4 @@ impl CandidatesDataSourceImpl {
 			})
 			.collect()
 	}
-
-	fn get_epoch_of_data_storage(
-		&self,
-		epoch_of_data_usage: McEpochNumber,
-	) -> Result<McEpochNumber, Box<dyn std::error::Error + Send + Sync>> {
-		offset_data_epoch(&epoch_of_data_usage).map_err(|offset| {
-			BadRequest(format!(
-				"Minimum supported epoch of data usage is {offset}, but {} was provided",
-				epoch_of_data_usage.0
-			))
-			.into()
-		})
-	}
 }