PoC: add sibling para heads to the RelayChainStateProof

cumulus/client/parachain-inherent/src/lib.rs

@@ -121,6 +121,11 @@ async fn collect_relay_storage_proof(
 	relevant_keys.extend(egress_channels.into_iter().map(|recipient| {
 		relay_well_known_keys::hrmp_channels(HrmpChannelId { sender: para_id, recipient })
 	}));
+	// TODO: maybe here? can we pass somehow `predefined_sibling_para_id`?
+	// TODO: maybe we can collect all hrmp sender/receipient paraId by default withtout need to change configuration?
+	// for sibling_para_id in predefined_sibling_para_id {
+	// 	relevant_keys.extend(relay_well_known_keys::para_head(sibling_para_id));
+	// }
 
 	relay_chain_interface
 		.prove_read(relay_parent, &relevant_keys)

cumulus/pallets/parachain-system/src/lib.rs

@@ -612,6 +612,15 @@ pub mod pallet {
 			)
 			.expect("Invalid relay chain state proof");
 
+			/// This reads actual para head for `T::SelfParaId::get()`
+			log::error!("PARA_HEAD: {:?}", relay_state_proof.read_included_para_head());
+			/// TODO: I would like to acheive something like this, 2001 can be replaced with some onchain configuration
+			let sibling_para_head_from_relaychain_state_proof = relay_state_proof.read_sibling_para_head(2001.into());
+			log::error!("SIBLING_PARA_HEAD: {:?}", sibling_para_head_from_relaychain_state_proof);
+			// TODO: add some callback similar as T::OnSystemEvent (or reuse this one)
+			// TODO: custom pallet, can store those in some list/map or whatever
+			T::OnSiblingParaHead(sibling_para_head_from_relaychain_state_proof);
+
 			// Update the desired maximum capacity according to the consensus hook.
 			let (consensus_hook_weight, capacity) =
 				T::ConsensusHook::on_state_proof(&relay_state_proof);

cumulus/pallets/parachain-system/src/relay_state_snapshot.rs

@@ -293,6 +293,12 @@ impl RelayChainStateProof {
 			.map_err(Error::ParaHead)
 	}
 
+	/// TODO: read from the `RelayChainStateProof` trie
+	pub fn read_sibling_para_head(&self, sibling_para_id: ParaId) -> Result<Option<relay_chain::HeadData>, Error> {
+		read_optional_entry(&self.trie_backend, &relay_chain::well_known_keys::para_head(sibling_para_id))
+			.map_err(Error::ParaHead)
+	}
+
 	/// Read the [`Slot`](relay_chain::Slot) from the relay chain state proof.
 	///
 	/// The slot is slot of the relay chain block this state proof was extracted from.

cumulus/polkadot-omni-node/lib/src/nodes/aura.rs

@@ -340,7 +340,11 @@ where
 
 		let client_for_aura = client.clone();
 		let params = SlotBasedParams {
-			create_inherent_data_providers: move |_, ()| async move { Ok(()) },
+			create_inherent_data_providers: move |db_hash, ()| {
+				// TODO: add here custom provider, which will read some runtime api/storage for set of paraIds and get their para heads?
+				// TODO: if we chanage this, how can we release this? As a breaking change?
+				async move { Ok(()) }
+			},
 			block_import,
 			para_client: client.clone(),
 			para_backend: backend.clone(),
@@ -461,7 +465,11 @@ where
 		let params = aura::ParamsWithExport {
 			export_pov: node_extra_args.export_pov,
 			params: AuraParams {
-				create_inherent_data_providers: move |_, ()| async move { Ok(()) },
+				create_inherent_data_providers: move |db_hash, ()| {
+					// TODO: add here custom provider, which will read some runtime api/storage for set of paraIds and get their para heads?
+					// TODO: if we chanage this, how can we release this? As a breaking change?
+					async move { Ok(()) }
+				},
 				block_import,
 				para_client: client.clone(),
 				para_backend: backend,

cumulus/primitives/parachain-inherent/src/lib.rs

@@ -54,7 +54,7 @@ pub struct ParachainInherentData {
 	/// - the relay dispatch queue sizes
 	/// - the list of egress HRMP channels (in the list of recipients form)
 	/// - the metadata for the egress HRMP channels
-	pub relay_chain_state: sp_trie::StorageProof,
+	pub relay_chain_state: sp_trie::StorageProof, // TODO: how to add here predefined sibling para heads (with state roots)?
 	/// Downward messages in the order they were sent.
 	pub downward_messages: Vec<InboundDownwardMessage>,
 	/// HRMP messages grouped by channels. The messages in the inner vec must be in order they