Parachains finality pallet (#1068)

* parachains finality

* parachains pallet test

* demo of how to configure GRANDPA pallet instance

* allow instances in parachains pallet

* spellcheck

* TODO + fix

* fmt

* removed invalid storage_keys file

* change all hashers to Blake2_128Concat

* use Twox64Concat for insertion position

* fix build

* fix compilation

* change ParaId and ParaHead types

* TODOs -> TODOs with issues refs

bridges/modules/grandpa/src/lib.rs

@@ -284,7 +284,7 @@ pub mod pallet {
 
 	/// Headers which have been imported into the pallet.
 	#[pallet::storage]
-	pub(super) type ImportedHeaders<T: Config<I>, I: 'static = ()> =
+	pub type ImportedHeaders<T: Config<I>, I: 'static = ()> =
 		StorageMap<_, Identity, BridgedBlockHash<T, I>, BridgedHeader<T, I>>;
 
 	/// The current GRANDPA Authority set.

bridges/modules/parachains/Cargo.toml

+[package]
+name = "pallet-bridge-parachains"
+version = "0.1.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2021"
+license = "GPL-3.0-or-later WITH Classpath-exception-2.0"
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.0.0", default-features = false }
+log = { version = "0.4.14", default-features = false }
+scale-info = { version = "2.1.1", default-features = false, features = ["derive"] }
+serde = { version = "1.0.101", optional = true }
+
+# Bridge Dependencies
+
+bp-polkadot-core = { path = "../../primitives/polkadot-core", default-features = false }
+bp-runtime = { path = "../../primitives/runtime", default-features = false }
+pallet-bridge-grandpa = { path = "../grandpa", default-features = false }
+
+# Substrate Dependencies
+
+frame-support = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+frame-system = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-core = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-runtime = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-std = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-trie = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+
+[dev-dependencies]
+bp-header-chain = { path = "../../primitives/header-chain" }
+bp-test-utils = { path = "../../primitives/test-utils" }
+sp-io = { git = "https://github.com/paritytech/substrate", branch = "master" }
+
+[features]
+default = ["std"]
+std = [
+	"bp-polkadot-core/std",
+	"bp-runtime/std",
+	"codec/std",
+	"frame-support/std",
+	"frame-system/std",
+	"log/std",
+	"pallet-bridge-grandpa/std",
+	"scale-info/std",
+	"serde",
+	"sp-core/std",
+	"sp-runtime/std",
+	"sp-std/std",
+	"sp-trie/std",
+]

bridges/modules/parachains/src/mock.rs

+// Copyright 2019-2021 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+use bp_runtime::Chain;
+use frame_support::{construct_runtime, parameter_types, weights::Weight};
+use sp_runtime::{
+	testing::{Header, H256},
+	traits::{BlakeTwo256, Header as HeaderT, IdentityLookup},
+	Perbill,
+};
+
+use crate as pallet_bridge_parachains;
+
+pub type AccountId = u64;
+pub type TestNumber = u64;
+
+pub type RelayBlockHeader =
+	sp_runtime::generic::Header<crate::RelayBlockNumber, crate::RelayBlockHasher>;
+
+type Block = frame_system::mocking::MockBlock<TestRuntime>;
+type UncheckedExtrinsic = frame_system::mocking::MockUncheckedExtrinsic<TestRuntime>;
+
+construct_runtime! {
+	pub enum TestRuntime where
+		Block = Block,
+		NodeBlock = Block,
+		UncheckedExtrinsic = UncheckedExtrinsic,
+	{
+		System: frame_system::{Pallet, Call, Config, Storage, Event<T>},
+		Grandpa1: pallet_bridge_grandpa::<Instance1>::{Pallet},
+		Grandpa2: pallet_bridge_grandpa::<Instance2>::{Pallet},
+		Parachains: pallet_bridge_parachains::{Pallet},
+	}
+}
+
+parameter_types! {
+	pub const BlockHashCount: TestNumber = 250;
+	pub const MaximumBlockWeight: Weight = 1024;
+	pub const MaximumBlockLength: u32 = 2 * 1024;
+	pub const AvailableBlockRatio: Perbill = Perbill::one();
+}
+
+impl frame_system::Config for TestRuntime {
+	type Origin = Origin;
+	type Index = u64;
+	type Call = Call;
+	type BlockNumber = TestNumber;
+	type Hash = H256;
+	type Hashing = BlakeTwo256;
+	type AccountId = AccountId;
+	type Lookup = IdentityLookup<Self::AccountId>;
+	type Header = Header;
+	type Event = ();
+	type BlockHashCount = BlockHashCount;
+	type Version = ();
+	type PalletInfo = PalletInfo;
+	type AccountData = ();
+	type OnNewAccount = ();
+	type OnKilledAccount = ();
+	type BaseCallFilter = frame_support::traits::Everything;
+	type SystemWeightInfo = ();
+	type DbWeight = ();
+	type BlockWeights = ();
+	type BlockLength = ();
+	type SS58Prefix = ();
+	type OnSetCode = ();
+	type MaxConsumers = frame_support::traits::ConstU32<16>;
+}
+
+parameter_types! {
+	pub const MaxRequests: u32 = 2;
+	pub const HeadersToKeep: u32 = 5;
+	pub const SessionLength: u64 = 5;
+	pub const NumValidators: u32 = 5;
+}
+
+impl pallet_bridge_grandpa::Config<pallet_bridge_grandpa::Instance1> for TestRuntime {
+	type BridgedChain = TestBridgedChain;
+	type MaxRequests = MaxRequests;
+	type HeadersToKeep = HeadersToKeep;
+	type WeightInfo = ();
+}
+
+impl pallet_bridge_grandpa::Config<pallet_bridge_grandpa::Instance2> for TestRuntime {
+	type BridgedChain = TestBridgedChain;
+	type MaxRequests = MaxRequests;
+	type HeadersToKeep = HeadersToKeep;
+	type WeightInfo = ();
+}
+
+parameter_types! {
+	pub const HeadsToKeep: u32 = 4;
+}
+
+impl pallet_bridge_parachains::Config for TestRuntime {
+	type BridgesGrandpaPalletInstance = pallet_bridge_grandpa::Instance1;
+	type HeadsToKeep = HeadsToKeep;
+}
+
+#[derive(Debug)]
+pub struct TestBridgedChain;
+
+impl Chain for TestBridgedChain {
+	type BlockNumber = crate::RelayBlockNumber;
+	type Hash = crate::RelayBlockHash;
+	type Hasher = crate::RelayBlockHasher;
+	type Header = RelayBlockHeader;
+
+	type AccountId = AccountId;
+	type Balance = u32;
+	type Index = u32;
+	type Signature = sp_runtime::testing::TestSignature;
+
+	fn max_extrinsic_size() -> u32 {
+		unreachable!()
+	}
+
+	fn max_extrinsic_weight() -> Weight {
+		unreachable!()
+	}
+}
+
+#[derive(Debug)]
+pub struct OtherBridgedChain;
+
+impl Chain for OtherBridgedChain {
+	type BlockNumber = u64;
+	type Hash = crate::RelayBlockHash;
+	type Hasher = crate::RelayBlockHasher;
+	type Header = sp_runtime::generic::Header<u64, crate::RelayBlockHasher>;
+
+	type AccountId = AccountId;
+	type Balance = u32;
+	type Index = u32;
+	type Signature = sp_runtime::testing::TestSignature;
+
+	fn max_extrinsic_size() -> u32 {
+		unreachable!()
+	}
+
+	fn max_extrinsic_weight() -> Weight {
+		unreachable!()
+	}
+}
+
+pub fn run_test<T>(test: impl FnOnce() -> T) -> T {
+	sp_io::TestExternalities::new(Default::default()).execute_with(test)
+}
+
+pub fn test_relay_header(
+	num: crate::RelayBlockNumber,
+	state_root: crate::RelayBlockHash,
+) -> RelayBlockHeader {
+	RelayBlockHeader::new(
+		num,
+		Default::default(),
+		state_root,
+		Default::default(),
+		Default::default(),
+	)
+}

bridges/primitives/polkadot-core/Cargo.toml

@@ -8,7 +8,9 @@ license = "GPL-3.0-or-later WITH Classpath-exception-2.0"
 
 [dependencies]
 parity-scale-codec = { version = "3.0.0", default-features = false, features = ["derive"] }
+parity-util-mem = { version = "0.11.0", optional = true }
 scale-info = { version = "2.1.1", default-features = false, features = ["derive"] }
+serde = { version = "1.0", optional = true, features = ["derive"] }
 
 # Bridge Dependencies
 
@@ -36,7 +38,9 @@ std = [
 	"frame-support/std",
 	"frame-system/std",
 	"parity-scale-codec/std",
+	"parity-util-mem",
 	"scale-info/std",
+	"serde",
 	"sp-api/std",
 	"sp-core/std",
 	"sp-runtime/std",

bridges/primitives/polkadot-core/src/lib.rs

@@ -43,6 +43,8 @@ use sp_std::prelude::Vec;
 pub use frame_support::{weights::constants::ExtrinsicBaseWeight, Parameter};
 pub use sp_runtime::{traits::Convert, Perbill};
 
+pub mod parachains;
+
 /// Number of extra bytes (excluding size of storage value itself) of storage proof, built at
 /// Polkadot-like chain. This mostly depends on number of entries in the storage trie.
 /// Some reserve is reserved to account future chain growth.

bridges/primitives/polkadot-core/src/parachains.rs

+// Copyright 2019-2021 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Primitives of polkadot-like chains, that are related to parachains functionality.
+//!
+//! Even though this (bridges) repository references polkadot repository, we can't
+//! reference polkadot crates from pallets. That's because bridges repository is
+//! included in the polkadot repository and included pallets are used by polkadot
+//! chains. Having pallets that are referencing polkadot, would mean that there may
+//! be two versions of polkadot crates included in the runtime. Which is bad.
+
+use frame_support::RuntimeDebug;
+use parity_scale_codec::{CompactAs, Decode, Encode, MaxEncodedLen};
+use scale_info::TypeInfo;
+use sp_core::Hasher;
+use sp_std::vec::Vec;
+
+#[cfg(feature = "std")]
+use serde::{Deserialize, Serialize};
+
+#[cfg(feature = "std")]
+use parity_util_mem::MallocSizeOf;
+
+/// Parachain id.
+///
+/// This is an equivalent of the `polkadot_parachain::Id`, which is a compact-encoded `u32`.
+#[derive(
+	Clone,
+	CompactAs,
+	Copy,
+	Decode,
+	Default,
+	Encode,
+	Eq,
+	Hash,
+	MaxEncodedLen,
+	Ord,
+	PartialEq,
+	PartialOrd,
+	RuntimeDebug,
+	TypeInfo,
+)]
+pub struct ParaId(pub u32);
+
+/// Parachain head.
+///
+/// This is an equivalent of the `polkadot_parachain::HeadData`.
+///
+/// The parachain head means (at least in Cumulus) a SCALE-encoded parachain header. Keep in mind
+/// that in Polkadot it is twice-encoded (so `header.encode().encode()`). We'll also do it to keep
+/// it binary-compatible (implies hash-compatibility) with other parachain pallets.
+#[derive(
+	PartialEq, Eq, Clone, PartialOrd, Ord, Encode, Decode, RuntimeDebug, TypeInfo, Default,
+)]
+#[cfg_attr(feature = "std", derive(Serialize, Deserialize, Hash, MallocSizeOf))]
+pub struct ParaHead(pub Vec<u8>);
+
+impl ParaHead {
+	/// Returns the hash of this head data.
+	pub fn hash(&self) -> crate::Hash {
+		sp_runtime::traits::BlakeTwo256::hash(&self.0)
+	}
+}
+
+/// Parachain head hash.
+pub type ParaHash = crate::Hash;
+
+/// Raw storage proof of parachain heads, stored in polkadot-like chain runtime.
+pub type ParachainHeadsProof = Vec<Vec<u8>>;