[light-client] remove pending parentchain tx-inclusion check (#1455)

* [itc-light-client] remove failing check for parentchain xt inclusion

* [itc-light-client] Add comment about justifying headers

* [itc-light-client] Just in case debug log unjustified headers

* [itc-light-client] typos in comments

* [itc-parentchain-block-importer] update obsolete documentation

core/parentchain/block-importer/src/block_importer.rs

@@ -114,13 +114,10 @@ impl<
 		for (signed_block, raw_events) in
 			blocks_to_import.into_iter().zip(events_to_import.into_iter())
 		{
-			// Check if there are any extrinsics in the to-be-imported block that we sent and cached in the light-client before.
-			// If so, remove them now from the cache.
-			if let Err(e) = self.validator_accessor.execute_mut_on_validator(|v| {
-				v.check_xt_inclusion(&signed_block.block)?;
-
-				v.submit_block(&signed_block)
-			}) {
+			if let Err(e) = self
+				.validator_accessor
+				.execute_mut_on_validator(|v| v.submit_block(&signed_block))
+			{
 				error!("[{:?}] Header submission to light client failed: {:?}", id, e);
 				return Err(e.into())
 			}

core/parentchain/light-client/src/io.rs

@@ -358,7 +358,6 @@ pub mod sgx_tests {
 		.unwrap();
 
 		assert_eq!(validator.genesis_hash().unwrap(), parachain_params.genesis_header.hash());
-		assert_eq!(validator.num_xt_to_be_included().unwrap(), 0);
 		assert_eq!(validator.latest_finalized_header().unwrap(), parachain_params.genesis_header);
 		assert_eq!(
 			validator.penultimate_finalized_block_header().unwrap(),

core/parentchain/light-client/src/lib.rs

@@ -74,8 +74,6 @@ where
 {
 	fn submit_block(&mut self, signed_block: &SignedBlock<Block>) -> Result<(), Error>;
 
-	fn check_xt_inclusion(&mut self, block: &Block) -> Result<(), Error>;
-
 	fn get_state(&self) -> &LightValidationState<Block>;
 }
 
@@ -85,8 +83,6 @@ pub trait ExtrinsicSender {
 }
 
 pub trait LightClientState<Block: ParentchainBlockTrait> {
-	fn num_xt_to_be_included(&self) -> Result<usize, Error>;
-
 	fn genesis_hash(&self) -> Result<HashFor<Block>, Error>;
 
 	fn latest_finalized_header(&self) -> Result<Block::Header, Error>;

core/parentchain/light-client/src/light_validation.rs

@@ -26,10 +26,9 @@ use core::iter::Iterator;
 use itp_ocall_api::EnclaveOnChainOCallApi;
 use itp_storage::{Error as StorageError, StorageProof, StorageProofChecker};
 use itp_types::parentchain::{IdentifyParentchain, ParentchainId};
-use log::*;
 use sp_runtime::{
 	generic::SignedBlock,
-	traits::{Block as ParentchainBlockTrait, Hash as HashTrait, Header as HeaderTrait},
+	traits::{Block as ParentchainBlockTrait, Header as HeaderTrait},
 	Justifications, OpaqueExtrinsic,
 };
 use std::{boxed::Box, fmt, sync::Arc, vec::Vec};
@@ -115,7 +114,10 @@ impl<Block: ParentchainBlockTrait, OcallApi: EnclaveOnChainOCallApi>
 			}
 		}
 
-		// A valid grandpa proof proves finalization of all previous unjustified blocks.
+		// Todo: Justifying the headers here is actually wrong, but it prevents an ever-growing
+		// `unjustified_headers` queue because in the parachain case we won't have justifications,
+		// and in solo chain setups we only get a justification upon an Grandpa authority change.
+		// Hence, we justify the headers here until we properly solve this in #1404.
 		relay.justify_headers();
 		relay.push_header_hash(header.hash());
 
@@ -128,17 +130,6 @@ impl<Block: ParentchainBlockTrait, OcallApi: EnclaveOnChainOCallApi>
 
 		Ok(())
 	}
-
-	fn submit_xt_to_be_included(&mut self, extrinsic: OpaqueExtrinsic) {
-		let relay = self.light_validation_state.get_relay_mut();
-		relay.verify_tx_inclusion.push(extrinsic);
-
-		debug!(
-			"[{:?}] {} extrinsics in cache, waiting for inclusion verification",
-			self.parentchain_id,
-			relay.verify_tx_inclusion.len()
-		);
-	}
 }
 
 impl<Block, OCallApi> Validator<Block> for LightValidation<Block, OCallApi>
@@ -160,44 +151,6 @@ where
 		self.submit_finalized_headers(header.clone(), vec![], justifications)
 	}
 
-	fn check_xt_inclusion(&mut self, block: &Block) -> Result<(), Error> {
-		let relay = self.light_validation_state.get_relay_mut();
-
-		if relay.verify_tx_inclusion.is_empty() {
-			return Ok(())
-		}
-
-		let mut found_xts = vec![];
-		block.extrinsics().iter().for_each(|xt| {
-			if let Some(index) = relay.verify_tx_inclusion.iter().position(|xt_opaque| {
-				<HashingFor<Block>>::hash_of(xt) == <HashingFor<Block>>::hash_of(xt_opaque)
-			}) {
-				found_xts.push(index);
-			}
-		});
-
-		// sort highest index first
-		found_xts.sort_by(|a, b| b.cmp(a));
-
-		let rm: Vec<OpaqueExtrinsic> =
-			found_xts.into_iter().map(|i| relay.verify_tx_inclusion.remove(i)).collect();
-
-		if !rm.is_empty() {
-			info!(
-				"[{:?}] Verified inclusion proof of {} extrinsics.",
-				self.parentchain_id,
-				rm.len()
-			);
-		}
-		debug!(
-			"[{:?}] {} extrinsics remaining in cache, waiting for inclusion verification",
-			self.parentchain_id,
-			relay.verify_tx_inclusion.len()
-		);
-
-		Ok(())
-	}
-
 	fn get_state(&self) -> &LightValidationState<Block> {
 		&self.light_validation_state
 	}
@@ -210,10 +163,6 @@ where
 	OCallApi: EnclaveOnChainOCallApi,
 {
 	fn send_extrinsics(&mut self, extrinsics: Vec<OpaqueExtrinsic>) -> Result<(), Error> {
-		for xt in extrinsics.iter() {
-			self.submit_xt_to_be_included(xt.clone());
-		}
-
 		self.ocall_api
 			.send_to_parentchain(extrinsics, &self.parentchain_id)
 			.map_err(|e| {
@@ -230,10 +179,6 @@ where
 	Block: ParentchainBlockTrait,
 	OCallApi: EnclaveOnChainOCallApi,
 {
-	fn num_xt_to_be_included(&self) -> Result<usize, Error> {
-		self.light_validation_state.num_xt_to_be_included()
-	}
-
 	fn genesis_hash(&self) -> Result<HashFor<Block>, Error> {
 		self.light_validation_state.genesis_hash()
 	}

core/parentchain/light-client/src/light_validation_state.rs

@@ -52,11 +52,6 @@ impl<Block> LightClientState<Block> for LightValidationState<Block>
 where
 	Block: ParentchainBlockTrait,
 {
-	fn num_xt_to_be_included(&self) -> Result<usize, Error> {
-		let relay = self.get_relay();
-		Ok(relay.verify_tx_inclusion.len())
-	}
-
 	fn genesis_hash(&self) -> Result<HashFor<Block>, Error> {
 		Ok(self.get_relay().genesis_hash)
 	}

core/parentchain/light-client/src/mocks/validator_mock.rs

@@ -49,10 +49,6 @@ impl Validator<Block> for ValidatorMock {
 		Ok(())
 	}
 
-	fn check_xt_inclusion(&mut self, _block: &Block) -> Result<()> {
-		Ok(())
-	}
-
 	fn get_state(&self) -> &LightValidationState<Block> {
 		&self.light_validation_state
 	}
@@ -65,10 +61,6 @@ impl ExtrinsicSender for ValidatorMock {
 }
 
 impl LightClientState<Block> for ValidatorMock {
-	fn num_xt_to_be_included(&self) -> Result<usize> {
-		todo!()
-	}
-
 	fn genesis_hash(&self) -> Result<HashFor<Block>> {
 		todo!()
 	}

core/parentchain/light-client/src/state.rs

@@ -17,10 +17,7 @@
 
 use codec::{Decode, Encode};
 use sp_consensus_grandpa::{AuthorityList, SetId};
-use sp_runtime::{
-	traits::{Block as BlockT, Header as HeaderT},
-	OpaqueExtrinsic,
-};
+use sp_runtime::traits::{Block as BlockT, Header as HeaderT};
 use std::{collections::VecDeque, fmt, vec::Vec};
 
 /// Defines the amount of parentchain headers to keep.
@@ -35,7 +32,6 @@ pub struct RelayState<Block: BlockT> {
 	pub current_validator_set_id: SetId,
 	header_hashes: VecDeque<Block::Hash>,
 	pub unjustified_headers: Vec<Block::Hash>, // Finalized headers without grandpa proof
-	pub verify_tx_inclusion: Vec<OpaqueExtrinsic>, // Transactions sent by the relay
 	pub scheduled_change: Option<ScheduledChangeAtBlock<Block::Header>>, // Scheduled Authorities change as indicated in the header's digest.
 }
 
@@ -79,7 +75,6 @@ impl<Block: BlockT> RelayState<Block> {
 			current_validator_set: validator_set,
 			current_validator_set_id: 0,
 			unjustified_headers: Vec::new(),
-			verify_tx_inclusion: Vec::new(),
 			scheduled_change: None,
 		}
 	}
@@ -95,11 +90,11 @@ impl<Block: BlockT> fmt::Debug for RelayState<Block> {
 		write!(
 			f,
 			"RelayInfo {{ last_finalized_block_header_number: {:?}, current_validator_set: {:?}, \
-        current_validator_set_id: {} amount of transaction in tx_inclusion_queue: {} }}",
+        current_validator_set_id: {}, number of unjustified headers: {} }}",
 			self.last_finalized_block_header.number(),
 			self.current_validator_set,
 			self.current_validator_set_id,
-			self.verify_tx_inclusion.len()
+			self.unjustified_headers.len()
 		)
 	}
 }