Do not make pallet-identity benchmarks signature-dependent (#8179)

Similar to #4756 for `pallet-nfts`, the changes proposed in this PR
intend to make benchmarks for `pallet-identity` signature-agnostic by
the inclusion of a benchmark helper with sane defaults to handle the
signing operations.

Author: José Molina Colmenero

cumulus/parachains/runtimes/people/people-rococo/src/people.rs

@@ -62,6 +62,8 @@ impl pallet_identity::Config for Runtime {
 	type UsernameGracePeriod = ConstU32<{ 3 * DAYS }>;
 	type MaxSuffixLength = ConstU32<7>;
 	type MaxUsernameLength = ConstU32<32>;
+	#[cfg(feature = "runtime-benchmarks")]
+	type BenchmarkHelper = ();
 	type WeightInfo = weights::pallet_identity::WeightInfo<Runtime>;
 }
 

cumulus/parachains/runtimes/people/people-westend/src/people.rs

@@ -62,6 +62,8 @@ impl pallet_identity::Config for Runtime {
 	type UsernameGracePeriod = ConstU32<{ 3 * DAYS }>;
 	type MaxSuffixLength = ConstU32<7>;
 	type MaxUsernameLength = ConstU32<32>;
+	#[cfg(feature = "runtime-benchmarks")]
+	type BenchmarkHelper = ();
 	type WeightInfo = weights::pallet_identity::WeightInfo<Runtime>;
 }
 

polkadot/runtime/common/src/integration_tests.rs

@@ -305,6 +305,8 @@ impl pallet_identity::Config for Test {
 	type UsernameGracePeriod = ConstU32<10>;
 	type MaxSuffixLength = ConstU32<7>;
 	type MaxUsernameLength = ConstU32<32>;
+	#[cfg(feature = "runtime-benchmarks")]
+	type BenchmarkHelper = ();
 	type WeightInfo = ();
 }
 

polkadot/runtime/rococo/src/lib.rs

@@ -780,6 +780,8 @@ impl pallet_identity::Config for Runtime {
 	type UsernameGracePeriod = ConstU32<{ 30 * DAYS }>;
 	type MaxSuffixLength = ConstU32<7>;
 	type MaxUsernameLength = ConstU32<32>;
+	#[cfg(feature = "runtime-benchmarks")]
+	type BenchmarkHelper = ();
 	type WeightInfo = weights::pallet_identity::WeightInfo<Runtime>;
 }
 

polkadot/runtime/westend/src/lib.rs

@@ -1127,6 +1127,8 @@ impl pallet_identity::Config for Runtime {
 	type UsernameGracePeriod = ConstU32<{ 30 * DAYS }>;
 	type MaxSuffixLength = ConstU32<7>;
 	type MaxUsernameLength = ConstU32<32>;
+	#[cfg(feature = "runtime-benchmarks")]
+	type BenchmarkHelper = ();
 	type WeightInfo = weights::pallet_identity::WeightInfo<Runtime>;
 }
 

prdoc/pr_8179.prdoc

@@ -0,0 +1,33 @@
+# Schema: Polkadot SDK PRDoc Schema (prdoc) v1.0.0
+# See doc at https://raw.githubusercontent.com/paritytech/polkadot-sdk/master/prdoc/schema_user.json
+
+title: Do not make pallet-identity benchmarks signature-dependent
+
+doc:
+  - audience: Runtime Dev
+    description: |
+      - Includes a `BenchmarkHelper` configuration item in `pallet-identity` to handle signing operations.
+      - Abstracts away the explicit link with Sr25519 schema in the benchmarks, allowing chains with a different one to be able to run them and calculate the weights.
+      - Adds a default implementation for the empty tuple that leaves the code equivalent.
+
+      Adding the following to your implementation of the `frame_identity::Config` should be enough:
+      ```diff
+      #[cfg(feature = "runtime-benchmarks")]
+      type BenchmarkHelper = ();
+      ```
+
+crates:
+    - name: pallet-identity
+      bump: major
+    - name: polkadot-runtime-common
+      bump: patch
+    - name: westend-runtime
+      bump: patch
+    - name: rococo-runtime
+      bump: patch
+    - name: pallet-alliance
+      bump: patch
+    - name: people-rococo-runtime
+      bump: patch
+    - name: people-westend-runtime
+      bump: patch

substrate/bin/node/runtime/src/lib.rs

@@ -1683,6 +1683,8 @@ impl pallet_identity::Config for Runtime {
 	type UsernameGracePeriod = ConstU32<{ 30 * DAYS }>;
 	type MaxSuffixLength = ConstU32<7>;
 	type MaxUsernameLength = ConstU32<32>;
+	#[cfg(feature = "runtime-benchmarks")]
+	type BenchmarkHelper = ();
 	type WeightInfo = pallet_identity::weights::SubstrateWeight<Runtime>;
 }
 

substrate/frame/alliance/src/mock.rs

@@ -103,6 +103,16 @@ ord_parameter_types! {
 type EnsureOneOrRoot = EitherOfDiverse<EnsureRoot<AccountId>, EnsureSignedBy<One, AccountId>>;
 type EnsureTwoOrRoot = EitherOfDiverse<EnsureRoot<AccountId>, EnsureSignedBy<Two, AccountId>>;
 
+#[cfg(feature = "runtime-benchmarks")]
+pub struct BenchmarkHelper;
+
+#[cfg(feature = "runtime-benchmarks")]
+impl pallet_identity::BenchmarkHelper<AccountU64, AccountU64> for BenchmarkHelper {
+	fn sign_message(_message: &[u8]) -> (AccountU64, AccountU64) {
+		(AccountU64(0), AccountU64(0))
+	}
+}
+
 impl pallet_identity::Config for Test {
 	type RuntimeEvent = RuntimeEvent;
 	type Currency = Balances;
@@ -123,6 +133,8 @@ impl pallet_identity::Config for Test {
 	type UsernameGracePeriod = UsernameGracePeriod;
 	type MaxSuffixLength = ConstU32<7>;
 	type MaxUsernameLength = ConstU32<32>;
+	#[cfg(feature = "runtime-benchmarks")]
+	type BenchmarkHelper = BenchmarkHelper;
 	type WeightInfo = ();
 }
 

substrate/frame/identity/src/benchmarking.rs

@@ -29,11 +29,7 @@ use frame_support::{
 	traits::{EnsureOrigin, Get, OnFinalize, OnInitialize},
 };
 use frame_system::RawOrigin;
-use sp_io::crypto::{sr25519_generate, sr25519_sign};
-use sp_runtime::{
-	traits::{Bounded, IdentifyAccount, One},
-	MultiSignature, MultiSigner,
-};
+use sp_runtime::traits::{Bounded, One};
 
 const SEED: u32 = 0;
 
@@ -131,11 +127,7 @@ fn bounded_username<T: Config>(username: Vec<u8>, suffix: Vec<u8>) -> Username<T
 	Username::<T>::try_from(full_username).expect("test usernames should fit within bounds")
 }
 
-#[benchmarks(
-	where
-		<T as frame_system::Config>::AccountId: From<sp_runtime::AccountId32>,
-		T::OffchainSignature: From<MultiSignature>,
-)]
+#[benchmarks]
 mod benchmarks {
 	use super::*;
 
@@ -625,16 +617,12 @@ mod benchmarks {
 		let username = bench_username();
 		let bounded_username = bounded_username::<T>(username.clone(), suffix.clone());
 
-		let public = sr25519_generate(0.into(), None);
-		let who_account: T::AccountId = MultiSigner::Sr25519(public).into_account().into();
+		let (public, signature) = T::BenchmarkHelper::sign_message(&bounded_username[..]);
+		let who_account = public.into_account();
 		let who_lookup = T::Lookup::unlookup(who_account.clone());
 
-		let signature = MultiSignature::Sr25519(
-			sr25519_sign(0.into(), &public, &bounded_username[..]).unwrap(),
-		);
-
 		// Verify signature here to avoid surprise errors at runtime
-		assert!(signature.verify(&bounded_username[..], &public.into()));
+		assert!(signature.verify(&bounded_username[..], &who_account));
 		let use_allocation = match p {
 			0 => false,
 			1 => true,

substrate/frame/identity/src/lib.rs

@@ -150,6 +150,26 @@ pub mod pallet {
 	use super::*;
 	use frame_support::pallet_prelude::*;
 
+	#[cfg(feature = "runtime-benchmarks")]
+	pub trait BenchmarkHelper<Public, Signature> {
+		fn sign_message(message: &[u8]) -> (Public, Signature);
+	}
+	#[cfg(feature = "runtime-benchmarks")]
+	impl BenchmarkHelper<sp_runtime::MultiSigner, sp_runtime::MultiSignature> for () {
+		fn sign_message(message: &[u8]) -> (sp_runtime::MultiSigner, sp_runtime::MultiSignature) {
+			let public = sp_io::crypto::sr25519_generate(0.into(), None);
+			let signature = sp_runtime::MultiSignature::Sr25519(
+				sp_io::crypto::sr25519_sign(
+					0.into(),
+					&public.into_account().try_into().unwrap(),
+					message,
+				)
+				.unwrap(),
+			);
+			(public.into(), signature)
+		}
+	}
+
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
 		/// The overarching event type.
@@ -227,6 +247,11 @@ pub mod pallet {
 		#[pallet::constant]
 		type MaxUsernameLength: Get<u32>;
 
+		/// A set of helper functions for benchmarking.
+		/// The default configuration `()` uses the `SR25519` signature schema.
+		#[cfg(feature = "runtime-benchmarks")]
+		type BenchmarkHelper: BenchmarkHelper<Self::SigningPublicKey, Self::OffchainSignature>;
+
 		/// Weight information for extrinsics in this pallet.
 		type WeightInfo: WeightInfo;
 	}