Adds election provider multi-block pallet (wip)

Cargo.toml

@@ -341,7 +341,9 @@ members = [
 	"substrate/frame/core-fellowship",
 	"substrate/frame/delegated-staking",
 	"substrate/frame/democracy",
+	"substrate/frame/election-provider-multi-block",
 	"substrate/frame/election-provider-multi-phase",
+  "substrate/frame/election-provider-multi-block/integration-tests",
 	"substrate/frame/election-provider-multi-phase/test-staking-e2e",
 	"substrate/frame/election-provider-support",
 	"substrate/frame/election-provider-support/benchmarking",
@@ -925,6 +927,7 @@ pallet-default-config-example = { path = "substrate/frame/examples/default-confi
 pallet-delegated-staking = { path = "substrate/frame/delegated-staking", default-features = false }
 pallet-democracy = { path = "substrate/frame/democracy", default-features = false }
 pallet-dev-mode = { path = "substrate/frame/examples/dev-mode", default-features = false }
+pallet-election-provider-multi-block = { path = "substrate/frame/election-provider-multi-block", default-features = false }
 pallet-election-provider-multi-phase = { path = "substrate/frame/election-provider-multi-phase", default-features = false }
 pallet-election-provider-support-benchmarking = { path = "substrate/frame/election-provider-support/benchmarking", default-features = false }
 pallet-elections-phragmen = { path = "substrate/frame/elections-phragmen", default-features = false }

prdoc/pr_6213.prdoc

@@ -0,0 +1,11 @@
+title: Adds multi-block election pallet
+
+doc:
+  - audience: Runtime Dev
+    description: |
+      This PR adds the `election-provider-multi-block` (EPM-MB) pallet, which is the multi-block
+      variant of the `election-provider-multi-phase` (EPM) pallet.
+
+crates:
+ - name: pallet-election-provider-multi-block
+   bump: major

substrate/frame/election-provider-multi-block/Cargo.toml

@@ -0,0 +1,72 @@
+[package]
+name = "pallet-election-provider-multi-block"
+version = "1.0.0"
+authors.workspace = true
+edition.workspace = true
+license = "Apache-2.0"
+homepage = "https://substrate.dev"
+repository.workspace = true
+description = "FRAME pallet election provider multi-block"
+readme = "README.md"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.6.1", default-features = false, features = [
+	"derive",
+] }
+scale-info = { version = "2.10.0", default-features = false, features = [
+	"derive",
+] }
+log = { version = "0.4.17", default-features = false }
+
+frame-support = { path = "../support", default-features = false }
+frame-system = { path = "../system", default-features = false }
+frame-benchmarking = { path = "../benchmarking", default-features = false }
+
+sp-io = { path = "../../primitives/io", default-features = false }
+sp-std = { path = "../../primitives/std", default-features = false }
+sp-core = { path = "../../primitives/core", default-features = false }
+sp-runtime = { path = "../../primitives/runtime", default-features = false }
+
+frame-election-provider-support = { default-features = false, path = "../election-provider-support" }
+sp-npos-elections = { default-features = false, path = "../../primitives/npos-elections" }
+
+[dev-dependencies]
+sp-tracing = { path = "../../primitives/tracing" }
+pallet-balances = { path = "../balances", default-features = false }
+parking_lot = "0.12.1"
+
+[features]
+default = ["std"]
+std = [
+	"codec/std",
+	"frame-benchmarking/std",
+	"frame-election-provider-support/std",
+	"frame-support/std",
+	"frame-system/std",
+	"log/std",
+	"pallet-balances/std",
+	"scale-info/std",
+	"sp-core/std",
+	"sp-io/std",
+	"sp-npos-elections/std",
+	"sp-runtime/std",
+	"sp-std/std",
+]
+
+runtime-benchmarks = [
+	"frame-benchmarking/runtime-benchmarks",
+	"frame-election-provider-support/runtime-benchmarks",
+	"pallet-balances/runtime-benchmarks",
+	"sp-runtime/runtime-benchmarks",
+]
+
+try-runtime = [
+	"frame-election-provider-support/try-runtime",
+	"frame-support/try-runtime",
+	"frame-system/try-runtime",
+	"pallet-balances/try-runtime",
+	"sp-runtime/try-runtime",
+]

substrate/frame/election-provider-multi-block/README.md

@@ -0,0 +1 @@
+# Election Provider multi-block

substrate/frame/election-provider-multi-block/integration-tests/Cargo.toml

@@ -0,0 +1,54 @@
+[package]
+name = "pallet-epm-mb-integrity-tests"
+version = "1.0.0"
+authors.workspace = true
+edition.workspace = true
+license = "Apache-2.0"
+homepage.workspace = true
+repository.workspace = true
+description = "FRAME election provider multi block pallet tests with staking pallet, bags-list and session pallets"
+publish = false
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dev-dependencies]
+parking_lot = { workspace = true, default-features = true }
+codec = { features = ["derive"], workspace = true, default-features = true }
+scale-info = { features = ["derive"], workspace = true, default-features = true }
+log = { workspace = true }
+
+sp-runtime = { workspace = true, default-features = true }
+sp-io = { workspace = true, default-features = true }
+sp-std = { workspace = true, default-features = true }
+sp-staking = { workspace = true, default-features = true }
+sp-core = { workspace = true, default-features = true }
+sp-npos-elections = { workspace = true }
+sp-tracing = { workspace = true, default-features = true }
+
+frame-system = { workspace = true, default-features = true }
+frame-support = { workspace = true, default-features = true }
+frame-election-provider-support = { workspace = true, default-features = true }
+
+pallet-election-provider-multi-block = { workspace = true, default-features = true }
+pallet-staking = { workspace = true, default-features = true }
+pallet-nomination-pools = { workspace = true, default-features = true }
+pallet-bags-list = { workspace = true, default-features = true }
+pallet-balances = { workspace = true, default-features = true }
+pallet-timestamp = { workspace = true, default-features = true }
+pallet-session = { workspace = true, default-features = true }
+
+[features]
+try-runtime = [
+	"frame-election-provider-support/try-runtime",
+	"frame-support/try-runtime",
+	"frame-system/try-runtime",
+	"pallet-bags-list/try-runtime",
+	"pallet-balances/try-runtime",
+	#"pallet-election-provider-multi-block/try-runtime",
+	"pallet-nomination-pools/try-runtime",
+	"pallet-session/try-runtime",
+	"pallet-staking/try-runtime",
+	"pallet-timestamp/try-runtime",
+	"sp-runtime/try-runtime",
+]

substrate/frame/election-provider-multi-block/integration-tests/src/lib.rs

@@ -0,0 +1,125 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#![cfg(test)]
+mod mock;
+
+pub(crate) const LOG_TARGET: &str = "integration-tests::epm-staking";
+
+use mock::*;
+
+use frame_election_provider_support::{bounds::ElectionBoundsBuilder, ElectionDataProvider};
+
+use frame_support::{assert_ok, traits::UnixTime};
+
+// syntactic sugar for logging.
+#[macro_export]
+macro_rules! log {
+	($level:tt, $patter:expr $(, $values:expr)* $(,)?) => {
+		log::$level!(
+			target: crate::LOG_TARGET,
+			concat!("🛠️  ", $patter)  $(, $values)*
+		)
+	};
+}
+
+fn log_current_time() {
+	log!(
+		info,
+		"block: {:?}, session: {:?}, era: {:?}, EPM phase: {:?} ts: {:?}",
+		System::block_number(),
+		Session::current_index(),
+		Staking::current_era(),
+		ElectionProvider::current_phase(),
+		Timestamp::now()
+	);
+}
+
+#[test]
+fn block_progression_works() {
+	let (mut ext, _pool_state, _) = ExtBuilder::default().build_offchainify();
+	ext.execute_with(|| {})
+}
+
+#[test]
+fn verify_snapshot() {
+	ExtBuilder::default().build_and_execute(|| {
+		assert_eq!(Pages::get(), 3);
+
+		// manually get targets and voters from staking to see the inspect the issue with the
+		// DataProvider.
+		let bounds = ElectionBoundsBuilder::default()
+			.targets_count((TargetSnapshotPerBlock::get() as u32).into())
+			.voters_count((VoterSnapshotPerBlock::get() as u32).into())
+			.build();
+
+		assert_ok!(<Staking as ElectionDataProvider>::electable_targets(bounds.targets, 2));
+		assert_ok!(<Staking as ElectionDataProvider>::electing_voters(bounds.voters, 2));
+	})
+}
+
+mod staking_integration {
+	use super::*;
+	use pallet_election_provider_multi_block::Phase;
+
+	#[test]
+	fn call_elect_multi_block() {
+		ExtBuilder::default().build_and_execute(|| {
+			assert_eq!(Pages::get(), 3);
+			assert_eq!(ElectionProvider::current_round(), 0);
+			assert_eq!(Staking::current_era(), Some(0));
+
+			let export_starts_at = election_prediction() - Pages::get();
+
+			assert!(Staking::election_data_lock().is_none());
+
+			// check that the election data provider lock is set during the snapshot phase and
+			// released afterwards.
+			roll_to_phase(Phase::Snapshot(Pages::get() - 1), false);
+			assert!(Staking::election_data_lock().is_some());
+
+			roll_one(None, false);
+			assert!(Staking::election_data_lock().is_some());
+			roll_one(None, false);
+			assert!(Staking::election_data_lock().is_some());
+			// snapshot phase done, election data lock was released.
+			roll_one(None, false);
+			assert_eq!(ElectionProvider::current_phase(), Phase::Signed);
+			assert!(Staking::election_data_lock().is_none());
+
+			// last block where phase is waiting for unsignned submissions.
+			roll_to(election_prediction() - 4, false);
+			assert_eq!(ElectionProvider::current_phase(), Phase::Unsigned(17));
+
+			// staking prepares first page of exposures.
+			roll_to(export_starts_at, false);
+			assert_eq!(ElectionProvider::current_phase(), Phase::Export(export_starts_at));
+
+			// staking prepares second page of exposures.
+			roll_to(election_prediction() - 2, false);
+			assert_eq!(ElectionProvider::current_phase(), Phase::Export(export_starts_at));
+
+			// staking prepares third page of exposures.
+			roll_to(election_prediction() - 1, false);
+
+			// election successfully, round & era progressed.
+			assert_eq!(ElectionProvider::current_phase(), Phase::Off);
+			assert_eq!(ElectionProvider::current_round(), 1);
+			assert_eq!(Staking::current_era(), Some(1));
+		})
+	}
+}