fc-babe (#20)

* fc-babe

* reset

* update

* propagate error

* update psdk branch

* reset cargo.toml

* update cargo.lock

* taplo format

Author: liamaharon

Cargo.lock

@@ -19,6 +19,7 @@ members = [
 	"frame/hotfix-sufficients",
 	"client/api",
 	"client/aura",
+	"client/babe",
 	"client/consensus",
 	"client/rpc-core",
 	"client/rpc",
@@ -91,6 +92,7 @@ sc-client-api = { git = "https://github.com/paritytech/polkadot-sdk", tag = "pol
 sc-client-db = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-stable2503-6", default-features = false }
 sc-consensus = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-stable2503-6" }
 sc-consensus-aura = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-stable2503-6" }
+sc-consensus-babe = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-stable2503-6" }
 sc-consensus-grandpa = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-stable2503-6" }
 sc-consensus-manual-seal = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-stable2503-6" }
 sc-executor = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-stable2503-6" }
@@ -112,6 +114,7 @@ sp-block-builder = { git = "https://github.com/paritytech/polkadot-sdk", tag = "
 sp-blockchain = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-stable2503-6", default-features = false }
 sp-consensus = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-stable2503-6", default-features = false }
 sp-consensus-aura = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-stable2503-6", default-features = false }
+sp-consensus-babe = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-stable2503-6", default-features = false }
 sp-consensus-grandpa = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-stable2503-6", default-features = false }
 sp-core = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-stable2503-6", default-features = false }
 sp-crypto-hashing = { git = "https://github.com/paritytech/polkadot-sdk", tag = "polkadot-stable2503-6", default-features = false }
@@ -176,6 +179,7 @@ ark-std = { version = "0.4.0", default-features = false }
 # Frontier Client
 fc-api = { path = "client/api" }
 fc-aura = { path = "client/aura" }
+fc-babe = { path = "client/babe" }
 fc-cli = { path = "client/cli", default-features = false }
 fc-consensus = { path = "client/consensus" }
 fc-db = { path = "client/db", default-features = false }

Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "fc-babe"
+version = "1.0.0-dev"
+authors = { workspace = true }
+edition = { workspace = true }
+license = "GPL-3.0-or-later WITH Classpath-exception-2.0"
+repository = { workspace = true }
+description = "Babe consensus data provider for pending runtime calls"
+
+[dependencies]
+# Substrate
+sc-client-api = { workspace = true }
+sc-consensus-babe = { workspace = true }
+sp-api = { workspace = true }
+sp-blockchain = { workspace = true }
+sp-consensus-babe = { workspace = true }
+sp-inherents = { workspace = true }
+sp-runtime = { workspace = true }
+sp-timestamp = { workspace = true }
+# Frontier
+fc-rpc = { workspace = true }

client/babe/Cargo.toml

@@ -0,0 +1,60 @@
+use std::{marker::PhantomData, sync::Arc};
+
+use fc_rpc::pending::ConsensusDataProvider;
+use sc_client_api::{AuxStore, UsageProvider};
+use sp_api::ProvideRuntimeApi;
+use sp_blockchain::Error;
+use sp_consensus_babe::{digests::CompatibleDigestItem, BabeApi, BabeConfiguration, Slot};
+use sp_inherents::InherentData;
+use sp_runtime::{traits::Block as BlockT, Digest, DigestItem};
+use sp_timestamp::TimestampInherentData;
+
+pub struct BabeConsensusDataProvider<B, C> {
+	babe_config: BabeConfiguration,
+	_phantom: PhantomData<(B, C)>,
+}
+
+impl<B, C> BabeConsensusDataProvider<B, C>
+where
+	B: BlockT,
+	C: AuxStore + ProvideRuntimeApi<B> + UsageProvider<B>,
+	C::Api: BabeApi<B>,
+{
+	/// Creates a new instance of the [`BabeConsensusDataProvider`], requires that `client`
+	/// implements [`sp_consensus_babe::BabeApi`]
+	pub fn new(client: Arc<C>) -> Result<Self, Error> {
+		let babe_config = sc_consensus_babe::configuration(&*client)?;
+		Ok(Self {
+			babe_config,
+			_phantom: PhantomData,
+		})
+	}
+}
+
+impl<B: BlockT, C: Send + Sync> ConsensusDataProvider<B> for BabeConsensusDataProvider<B, C> {
+	fn create_digest(
+		&self,
+		_parent: &B::Header,
+		data: &InherentData,
+	) -> Result<Digest, sp_inherents::Error> {
+		let timestamp = data
+			.timestamp_inherent_data()?
+			.expect("Timestamp is always present; qed");
+
+		let slot_duration = self.babe_config.slot_duration();
+		let slot = Slot::from_timestamp(timestamp, slot_duration);
+
+		let digest_item = <DigestItem as CompatibleDigestItem>::babe_pre_digest(
+			sp_consensus_babe::digests::PreDigest::SecondaryPlain(
+				sp_consensus_babe::digests::SecondaryPlainPreDigest {
+					slot,
+					authority_index: 0, // Use first authority for pending blocks
+				},
+			),
+		);
+
+		Ok(Digest {
+			logs: vec![digest_item],
+		})
+	}
+}