[unstable2507] Backport #9632 (#9654)

Backport #9632 into `unstable2507` from sigurpol.

See the
[documentation](https://github.com/paritytech/polkadot-sdk/blob/master/docs/BACKPORT.md)
on how to use this bot.

**NOTE: A breaking change is necessary to add support for the new
extrinsic to lazily prune era and to let runtime configure
`MaxPruningItems`. This is why the semver check below has been
bypassed.** Being the branch `unstable`, this should be acceptable.

<!--
  # To be used by other automation, do not modify:
  original-pr-number: #${pull_number}
-->

---------

Co-authored-by: Paolo La Camera <[email protected]>
Co-authored-by: cmd[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: 3 people

cumulus/parachains/runtimes/assets/asset-hub-westend/src/staking.rs

@@ -264,6 +264,7 @@ parameter_types! {
 	pub const MaxNominations: u32 = <NposCompactSolution16 as frame_election_provider_support::NposSolution>::LIMIT as u32;
 	pub storage PlanningEraOffset: u32 = prod_or_fast!(2, 1);
 	pub const MaxEraDuration: u64 = RelaySessionDuration::get() as u64 * RELAY_CHAIN_SLOT_DURATION_MILLIS as u64 * SessionsPerEra::get() as u64;
+	pub MaxPruningItems: u32 = 100;
 }
 
 impl pallet_staking_async::Config for Runtime {
@@ -296,6 +297,7 @@ impl pallet_staking_async::Config for Runtime {
 	type PlanningEraOffset = PlanningEraOffset;
 	type RcClientInterface = StakingRcClient;
 	type MaxEraDuration = MaxEraDuration;
+	type MaxPruningItems = MaxPruningItems;
 }
 
 impl pallet_staking_async_rc_client::Config for Runtime {

cumulus/parachains/runtimes/assets/asset-hub-westend/src/weights/pallet_staking_async.rs

@@ -0,0 +1,15 @@
+title: 'staking-async: implement lazy era pruning extrinsic'
+doc:
+- audience: Runtime User
+  description: |-
+    Move era pruning from automatic unbounded deletions to a permissionless lazy pruning system.
+    The new system processes era pruning across multiple blocks using a state machine pattern, ensuring storage operations remain bounded and preventing PoV size exhaustion.
+
+crates:
+- name: pallet-staking-async
+  bump: major
+  validate: false
+- name: asset-hub-westend-runtime
+  bump: minor
+- name: pallet-staking-async-parachain-runtime
+  bump: minor

prdoc/pr_9632.prdoc

@@ -316,6 +316,7 @@ parameter_types! {
 	pub static SlashDeferredDuration: u32 = 2;
 	pub static SessionsPerEra: u32 = 6;
 	pub static PlanningEraOffset: u32 = 2;
+	pub MaxPruningItems: u32 = 100;
 }
 
 impl pallet_staking_async::Config for Runtime {
@@ -341,6 +342,7 @@ impl pallet_staking_async::Config for Runtime {
 	type Slash = ();
 	type SlashDeferDuration = SlashDeferredDuration;
 	type MaxEraDuration = ();
+	type MaxPruningItems = MaxPruningItems;
 
 	type HistoryDepth = ConstU32<7>;
 	type MaxControllersInDeprecationBatch = ();

substrate/frame/staking-async/ahm-test/src/ah/mock.rs

@@ -251,6 +251,7 @@ parameter_types! {
 	// frequently. On Kusama and Polkadot, a higher value like 7 × ideal_era_duration is more
 	// appropriate.
 	pub const MaxEraDuration: u64 = RelaySessionDuration::get() as u64 * RELAY_CHAIN_SLOT_DURATION_MILLIS as u64 * SessionsPerEra::get() as u64;
+	pub MaxPruningItems: u32 = 100;
 }
 
 impl pallet_staking_async::Config for Runtime {
@@ -278,9 +279,10 @@ impl pallet_staking_async::Config for Runtime {
 	type HistoryDepth = frame_support::traits::ConstU32<84>;
 	type MaxControllersInDeprecationBatch = MaxControllersInDeprecationBatch;
 	type EventListeners = (NominationPools, DelegatedStaking);
-	type WeightInfo = weights::pallet_staking_async::WeightInfo<Runtime>;
+	type WeightInfo = pallet_staking_async::weights::SubstrateWeight<Runtime>;
 	type MaxInvulnerables = frame_support::traits::ConstU32<20>;
 	type MaxEraDuration = MaxEraDuration;
+	type MaxPruningItems = MaxPruningItems;
 	type PlanningEraOffset =
 		pallet_staking_async::PlanningEraOffsetOf<Self, RelaySessionDuration, ConstU32<10>>;
 	type RcClientInterface = StakingRcClient;
@@ -481,41 +483,3 @@ where
 		UncheckedExtrinsic::new_bare(call)
 	}
 }
-
-#[cfg(test)]
-mod tests {
-	use super::*;
-	use frame_support::weights::constants::{WEIGHT_PROOF_SIZE_PER_KB, WEIGHT_REF_TIME_PER_MILLIS};
-	use pallet_staking_async::WeightInfo;
-
-	fn weight_diff(block: Weight, op: Weight) {
-		log::info!(
-			target: "runtime",
-			"ref_time: {:?}ms {:.4} of total",
-			op.ref_time() / WEIGHT_REF_TIME_PER_MILLIS,
-			op.ref_time() as f64 / block.ref_time() as f64
-		);
-		log::info!(
-			target: "runtime",
-			"proof_size: {:?}kb {:.4} of total",
-			op.proof_size() / WEIGHT_PROOF_SIZE_PER_KB,
-			op.proof_size() as f64 / block.proof_size() as f64
-		);
-	}
-
-	#[test]
-	fn polkadot_prune_era() {
-		sp_tracing::try_init_simple();
-		let prune_era = <Runtime as pallet_staking_async::Config>::WeightInfo::prune_era(600);
-		let block_weight = <Runtime as frame_system::Config>::BlockWeights::get().max_block;
-		weight_diff(block_weight, prune_era);
-	}
-
-	#[test]
-	fn kusama_prune_era() {
-		sp_tracing::try_init_simple();
-		let prune_era = <Runtime as pallet_staking_async::Config>::WeightInfo::prune_era(1000);
-		let block_weight = <Runtime as frame_system::Config>::BlockWeights::get().max_block;
-		weight_diff(block_weight, prune_era);
-	}
-}