ParachainHost: No need to be generic over the block or hash type (#2537)

The `BlockNumber` and `Hash` are fixed types any way.

polkadot/primitives/src/runtime_api.rs

@@ -116,11 +116,10 @@
 use crate::{
 	async_backing, slashing, vstaging, AsyncBackingParams, BlockNumber, CandidateCommitments,
 	CandidateEvent, CandidateHash, CommittedCandidateReceipt, CoreState, DisputeState,
-	ExecutorParams, GroupRotationInfo, OccupiedCoreAssumption, PersistedValidationData,
+	ExecutorParams, GroupRotationInfo, Hash, OccupiedCoreAssumption, PersistedValidationData,
 	PvfCheckStatement, ScrapedOnChainVotes, SessionIndex, SessionInfo, ValidatorId, ValidatorIndex,
 	ValidatorSignature,
 };
-use parity_scale_codec::{Decode, Encode};
 use polkadot_core_primitives as pcp;
 use polkadot_parachain_primitives::primitives as ppp;
 use sp_std::{collections::btree_map::BTreeMap, prelude::*};
@@ -128,18 +127,18 @@ use sp_std::{collections::btree_map::BTreeMap, prelude::*};
 sp_api::decl_runtime_apis! {
 	/// The API for querying the state of parachains on-chain.
 	#[api_version(5)]
-	pub trait ParachainHost<H: Encode + Decode = pcp::v2::Hash, N: Encode + Decode = pcp::v2::BlockNumber> {
+	pub trait ParachainHost {
 		/// Get the current validators.
 		fn validators() -> Vec<ValidatorId>;
 
 		/// Returns the validator groups and rotation info localized based on the hypothetical child
 		///  of a block whose state  this is invoked on. Note that `now` in the `GroupRotationInfo`
 		/// should be the successor of the number of the block.
-		fn validator_groups() -> (Vec<Vec<ValidatorIndex>>, GroupRotationInfo<N>);
+		fn validator_groups() -> (Vec<Vec<ValidatorIndex>>, GroupRotationInfo<BlockNumber>);
 
 		/// Yields information on all availability cores as relevant to the child block.
 		/// Cores are either free or occupied. Free cores can have paras assigned to them.
-		fn availability_cores() -> Vec<CoreState<H, N>>;
+		fn availability_cores() -> Vec<CoreState<Hash, BlockNumber>>;
 
 		/// Yields the persisted validation data for the given `ParaId` along with an assumption that
 		/// should be used if the para currently occupies a core.
@@ -147,15 +146,15 @@ sp_api::decl_runtime_apis! {
 		/// Returns `None` if either the para is not registered or the assumption is `Freed`
 		/// and the para already occupies a core.
 		fn persisted_validation_data(para_id: ppp::Id, assumption: OccupiedCoreAssumption)
-			-> Option<PersistedValidationData<H, N>>;
+			-> Option<PersistedValidationData<Hash, BlockNumber>>;
 
 		/// Returns the persisted validation data for the given `ParaId` along with the corresponding
 		/// validation code hash. Instead of accepting assumption about the para, matches the validation
 		/// data hash against an expected one and yields `None` if they're not equal.
 		fn assumed_validation_data(
 			para_id: ppp::Id,
-			expected_persisted_validation_data_hash: pcp::v2::Hash,
-		) -> Option<(PersistedValidationData<H, N>, ppp::ValidationCodeHash)>;
+			expected_persisted_validation_data_hash: Hash,
+		) -> Option<(PersistedValidationData<Hash, BlockNumber>, ppp::ValidationCodeHash)>;
 
 		/// Checks if the given validation outputs pass the acceptance criteria.
 		fn check_validation_outputs(para_id: ppp::Id, outputs: CandidateCommitments) -> bool;
@@ -169,30 +168,34 @@ sp_api::decl_runtime_apis! {
 		///
 		/// Returns `None` if either the para is not registered or the assumption is `Freed`
 		/// and the para already occupies a core.
-		fn validation_code(para_id: ppp::Id, assumption: OccupiedCoreAssumption)
-			-> Option<ppp::ValidationCode>;
+		fn validation_code(
+			para_id: ppp::Id,
+			assumption: OccupiedCoreAssumption,
+		) -> Option<ppp::ValidationCode>;
 
 		/// Get the receipt of a candidate pending availability. This returns `Some` for any paras
 		/// assigned to occupied cores in `availability_cores` and `None` otherwise.
-		fn candidate_pending_availability(para_id: ppp::Id) -> Option<CommittedCandidateReceipt<H>>;
+		fn candidate_pending_availability(para_id: ppp::Id) -> Option<CommittedCandidateReceipt<Hash>>;
 
 		/// Get a vector of events concerning candidates that occurred within a block.
-		fn candidate_events() -> Vec<CandidateEvent<H>>;
+		fn candidate_events() -> Vec<CandidateEvent<Hash>>;
 
 		/// Get all the pending inbound messages in the downward message queue for a para.
 		fn dmq_contents(
 			recipient: ppp::Id,
-		) -> Vec<pcp::v2::InboundDownwardMessage<N>>;
+		) -> Vec<pcp::v2::InboundDownwardMessage<BlockNumber>>;
 
 		/// Get the contents of all channels addressed to the given recipient. Channels that have no
 		/// messages in them are also included.
-		fn inbound_hrmp_channels_contents(recipient: ppp::Id) -> BTreeMap<ppp::Id, Vec<pcp::v2::InboundHrmpMessage<N>>>;
+		fn inbound_hrmp_channels_contents(
+			recipient: ppp::Id,
+		) -> BTreeMap<ppp::Id, Vec<pcp::v2::InboundHrmpMessage<BlockNumber>>>;
 
 		/// Get the validation code from its hash.
 		fn validation_code_by_hash(hash: ppp::ValidationCodeHash) -> Option<ppp::ValidationCode>;
 
 		/// Scrape dispute relevant from on-chain, backing votes and resolved disputes.
-		fn on_chain_votes() -> Option<ScrapedOnChainVotes<H>>;
+		fn on_chain_votes() -> Option<ScrapedOnChainVotes<Hash>>;
 
 		/***** Added in v2 *****/
 
@@ -253,7 +256,7 @@ sp_api::decl_runtime_apis! {
 
 		/// Returns the state of parachain backing for a given para.
 		#[api_version(7)]
-		fn para_backing_state(_: ppp::Id) -> Option<async_backing::BackingState<H, N>>;
+		fn para_backing_state(_: ppp::Id) -> Option<async_backing::BackingState<Hash, BlockNumber>>;
 
 		/// Returns candidate's acceptance limitations for asynchronous backing for a relay parent.
 		#[api_version(7)]