HRMP: Data structures and plumbing

core-primitives/src/lib.rs

@@ -102,6 +102,25 @@ pub struct InboundDownwardMessage<BlockNumber = crate::BlockNumber> {
 	pub msg: DownwardMessage,
 }
 
+/// An HRMP message seen from the perspective of a recipient.
+#[derive(codec::Encode, codec::Decode, Clone, sp_runtime::RuntimeDebug, PartialEq)]
+pub struct InboundHrmpMessage<BlockNumber = crate::BlockNumber> {
+	/// The block number at which this message was sent.
+	/// Specifically, it is the block number at which the candidate that sends this message was
+	/// enacted.
+	pub sent_at: BlockNumber,
+	/// The message payload.
+	pub data: sp_std::vec::Vec<u8>,
+}
+
+#[derive(codec::Encode, codec::Decode, Clone, sp_runtime::RuntimeDebug, PartialEq, Eq, Hash)]
+pub struct OutboundHrmpMessage<Id> {
+	/// The para that will get this message in its downward message queue.
+	pub recipient: Id,
+	/// The message payload.
+	pub data: sp_std::vec::Vec<u8>,
+}
+
 /// V1 primitives.
 pub mod v1 {
 	pub use super::*;

node/collation-generation/src/lib.rs

@@ -274,10 +274,12 @@ async fn handle_new_activations<Context: SubsystemContext>(
 
 				let commitments = CandidateCommitments {
 					upward_messages: collation.upward_messages,
+					horizontal_messages: collation.horizontal_messages,
 					new_validation_code: collation.new_validation_code,
 					head_data: collation.head_data,
 					erasure_root,
 					processed_downward_messages: collation.processed_downward_messages,
+					hrmp_watermark: collation.hrmp_watermark,
 				};
 
 				let ccr = CandidateReceipt {
@@ -382,12 +384,14 @@ mod tests {
 		fn test_collation() -> Collation {
 			Collation {
 				upward_messages: Default::default(),
+				horizontal_messages: Default::default(),
 				new_validation_code: Default::default(),
 				head_data: Default::default(),
 				proof_of_validity: PoV {
 					block_data: BlockData(Vec::new()),
 				},
 				processed_downward_messages: Default::default(),
+				hrmp_watermark: Default::default(),
 			}
 		}
 

node/core/backing/src/lib.rs

@@ -717,10 +717,12 @@ impl CandidateBackingJob {
 
 		let commitments = CandidateCommitments {
 			upward_messages: outputs.upward_messages,
+			horizontal_messages: outputs.horizontal_messages,
 			erasure_root,
 			new_validation_code: outputs.new_validation_code,
 			head_data: outputs.head_data,
 			processed_downward_messages: outputs.processed_downward_messages,
+			hrmp_watermark: outputs.hrmp_watermark,
 		};
 
 		let res = match with_commitments(commitments) {
@@ -1200,9 +1202,11 @@ mod tests {
 					tx.send(Ok(
 						ValidationResult::Valid(ValidationOutputs {
 							head_data: expected_head_data.clone(),
+							horizontal_messages: Vec::new(),
 							upward_messages: Vec::new(),
 							new_validation_code: None,
 							processed_downward_messages: 0,
+							hrmp_watermark: 0,
 						}, test_state.validation_data.persisted),
 					)).unwrap();
 				}
@@ -1328,8 +1332,10 @@ mod tests {
 						ValidationResult::Valid(ValidationOutputs {
 							head_data: expected_head_data.clone(),
 							upward_messages: Vec::new(),
+							horizontal_messages: Vec::new(),
 							new_validation_code: None,
 							processed_downward_messages: 0,
+							hrmp_watermark: 0,
 						}, test_state.validation_data.persisted),
 					)).unwrap();
 				}
@@ -1477,8 +1483,10 @@ mod tests {
 						ValidationResult::Valid(ValidationOutputs {
 							head_data: expected_head_data.clone(),
 							upward_messages: Vec::new(),
+							horizontal_messages: Vec::new(),
 							new_validation_code: None,
 							processed_downward_messages: 0,
+							hrmp_watermark: 0,
 						}, test_state.validation_data.persisted),
 					)).unwrap();
 				}
@@ -1660,8 +1668,10 @@ mod tests {
 						ValidationResult::Valid(ValidationOutputs {
 							head_data: expected_head_data.clone(),
 							upward_messages: Vec::new(),
+							horizontal_messages: Vec::new(),
 							new_validation_code: None,
 							processed_downward_messages: 0,
+							hrmp_watermark: 0,
 						}, test_state.validation_data.persisted),
 					)).unwrap();
 				}

node/core/candidate-validation/src/lib.rs

@@ -489,8 +489,10 @@ fn validate_candidate_exhaustive<B: ValidationBackend, S: SpawnNamed + 'static>(
 			let outputs = ValidationOutputs {
 				head_data: res.head_data,
 				upward_messages: res.upward_messages,
+				horizontal_messages: res.horizontal_messages,
 				new_validation_code: res.new_validation_code,
 				processed_downward_messages: res.processed_downward_messages,
+				hrmp_watermark: res.hrmp_watermark,
 			};
 			Ok(ValidationResult::Valid(outputs, persisted_validation_data))
 		}
@@ -833,7 +835,9 @@ mod tests {
 			head_data: HeadData(vec![1, 1, 1]),
 			new_validation_code: Some(vec![2, 2, 2].into()),
 			upward_messages: Vec::new(),
+			horizontal_messages: Vec::new(),
 			processed_downward_messages: 0,
+			hrmp_watermark: 0,
 		};
 
 		let v = validate_candidate_exhaustive::<MockValidationBackend, _>(
@@ -848,7 +852,9 @@ mod tests {
 		assert_matches!(v, ValidationResult::Valid(outputs, used_validation_data) => {
 			assert_eq!(outputs.head_data, HeadData(vec![1, 1, 1]));
 			assert_eq!(outputs.upward_messages, Vec::<UpwardMessage>::new());
+			assert_eq!(outputs.horizontal_messages, Vec::new());
 			assert_eq!(outputs.new_validation_code, Some(vec![2, 2, 2].into()));
+			assert_eq!(outputs.hrmp_watermark, 0);
 			assert_eq!(used_validation_data, validation_data);
 		});
 	}

node/primitives/src/lib.rs

@@ -28,7 +28,7 @@ use polkadot_primitives::v1::{
 	Hash, CommittedCandidateReceipt, CandidateReceipt, CompactStatement,
 	EncodeAs, Signed, SigningContext, ValidatorIndex, ValidatorId,
 	UpwardMessage, ValidationCode, PersistedValidationData, ValidationData,
-	HeadData, PoV, CollatorPair, Id as ParaId, ValidationOutputs, CandidateHash,
+	HeadData, PoV, CollatorPair, Id as ParaId, OutboundHrmpMessage, ValidationOutputs, CandidateHash,
 };
 use polkadot_statement_table::{
 	generic::{
@@ -252,9 +252,11 @@ impl std::convert::TryFrom<FromTableMisbehavior> for MisbehaviorReport {
 /// - does not contain the erasure root; that's computed at the Polkadot level, not at Cumulus
 /// - contains a proof of validity.
 #[derive(Clone, Encode, Decode)]
-pub struct Collation {
+pub struct Collation<BlockNumber = polkadot_primitives::v1::BlockNumber> {
 	/// Messages destined to be interpreted by the Relay chain itself.
 	pub upward_messages: Vec<UpwardMessage>,
+	/// The horizontal messages sent by the parachain.
+	pub horizontal_messages: Vec<OutboundHrmpMessage<ParaId>>,
 	/// New validation code.
 	pub new_validation_code: Option<ValidationCode>,
 	/// The head-data produced as a result of execution.
@@ -263,6 +265,8 @@ pub struct Collation {
 	pub proof_of_validity: PoV,
 	/// The number of messages processed from the DMQ.
 	pub processed_downward_messages: u32,
+	/// The mark which specifies the block number up to which all inbound HRMP messages are processed.
+	pub hrmp_watermark: BlockNumber,
 }
 
 /// Configuration for the collation generator

parachain/src/primitives.rs

@@ -28,7 +28,7 @@ use serde::{Serialize, Deserialize};
 #[cfg(feature = "std")]
 use sp_core::bytes;
 
-use polkadot_core_primitives::Hash;
+use polkadot_core_primitives::{Hash, OutboundHrmpMessage};
 
 /// Block number type used by the relay chain.
 pub use polkadot_core_primitives::BlockNumber as RelayChainBlockNumber;
@@ -186,6 +186,16 @@ impl<T: Encode + Decode + Default> AccountIdConversion<T> for Id {
 	}
 }
 
+/// A type that uniquely identifies an HRMP channel. An HRMP channel is unidirectional
+#[derive(Clone, PartialEq, Eq, Encode, Decode, RuntimeDebug)]
+#[cfg_attr(feature = "std", derive(Hash))]
+pub struct HrmpChannelId {
+	/// The para that acts as the sender in this channel.
+	pub sender: Id,
+	/// The para that acts as the recipient in this channel.
+	pub recipient: Id,
+}
+
 /// A message from a parachain to its Relay Chain.
 pub type UpwardMessage = Vec<u8>;
 
@@ -212,7 +222,7 @@ pub struct ValidationParams {
 }
 
 /// The result of parachain validation.
-// TODO: egress and balance uploads (https://github.com/paritytech/polkadot/issues/220)
+// TODO: balance uploads (https://github.com/paritytech/polkadot/issues/220)
 #[derive(PartialEq, Eq, Encode)]
 #[cfg_attr(feature = "std", derive(Debug, Decode))]
 pub struct ValidationResult {
@@ -222,8 +232,12 @@ pub struct ValidationResult {
 	pub new_validation_code: Option<ValidationCode>,
 	/// Upward messages send by the Parachain.
 	pub upward_messages: Vec<UpwardMessage>,
+	/// Outbound horizontal messages sent by the parachain.
+	pub horizontal_messages: Vec<OutboundHrmpMessage<Id>>,
 	/// Number of downward messages that were processed by the Parachain.
 	///
 	/// It is expected that the Parachain processes them from first to last.
 	pub processed_downward_messages: u32,
+	/// The mark which specifies the block number up to which all inbound HRMP messages are processed.
+	pub hrmp_watermark: RelayChainBlockNumber,
 }

parachain/test-parachains/adder/src/wasm_validation.rs

@@ -17,12 +17,13 @@
 //! WASM validation for adder parachain.
 
 use crate::{HeadData, BlockData};
-use core::{intrinsics, panic};
+use core::panic;
+use sp_std::vec::Vec;
 use parachain::primitives::{ValidationResult, HeadData as GenericHeadData};
 use codec::{Encode, Decode};
 
 #[no_mangle]
-pub extern fn validate_block(params: *const u8, len: usize) -> u64 {
+pub extern "C" fn validate_block(params: *const u8, len: usize) -> u64 {
 	let params = unsafe { parachain::load_params(params, len) };
 	let parent_head = HeadData::decode(&mut &params.parent_head.0[..])
 		.expect("invalid parent head format.");
@@ -38,7 +39,9 @@ pub extern fn validate_block(params: *const u8, len: usize) -> u64 {
 			head_data: GenericHeadData(new_head.encode()),
 			new_validation_code: None,
 			upward_messages: sp_std::vec::Vec::new(),
+			horizontal_messages: sp_std::vec::Vec::new(),
 			processed_downward_messages: 0,
+			hrmp_watermark: params.relay_chain_height,
 		}
 	)
 }

primitives/src/v1.rs

@@ -29,14 +29,14 @@ pub use runtime_primitives::traits::{BlakeTwo256, Hash as HashT};
 
 // Export some core primitives.
 pub use polkadot_core_primitives::v1::{
-	BlockNumber, Moment, Signature, AccountPublic, AccountId, AccountIndex,
-	ChainId, Hash, Nonce, Balance, Header, Block, BlockId, UncheckedExtrinsic,
-	Remark, DownwardMessage, InboundDownwardMessage, CandidateHash,
+	BlockNumber, Moment, Signature, AccountPublic, AccountId, AccountIndex, ChainId, Hash, Nonce,
+	Balance, Header, Block, BlockId, UncheckedExtrinsic, Remark, DownwardMessage,
+	InboundDownwardMessage, CandidateHash, InboundHrmpMessage, OutboundHrmpMessage,
 };
 
 // Export some polkadot-parachain primitives
 pub use polkadot_parachain::primitives::{
-	Id, LOWEST_USER_ID, UpwardMessage, HeadData, BlockData, ValidationCode,
+	Id, LOWEST_USER_ID, HrmpChannelId, UpwardMessage, HeadData, BlockData, ValidationCode,
 };
 
 // Export some basic parachain primitives from v0.
@@ -317,18 +317,24 @@ pub struct ValidationOutputs {
 	pub head_data: HeadData,
 	/// Upward messages to the relay chain.
 	pub upward_messages: Vec<UpwardMessage>,
+	/// The horizontal messages sent by the parachain.
+	pub horizontal_messages: Vec<OutboundHrmpMessage<Id>>,
 	/// The new validation code submitted by the execution, if any.
 	pub new_validation_code: Option<ValidationCode>,
 	/// The number of messages processed from the DMQ.
 	pub processed_downward_messages: u32,
+	/// The mark which specifies the block number up to which all inbound HRMP messages are processed.
+	pub hrmp_watermark: BlockNumber,
 }
 
 /// Commitments made in a `CandidateReceipt`. Many of these are outputs of validation.
 #[derive(PartialEq, Eq, Clone, Encode, Decode)]
 #[cfg_attr(feature = "std", derive(Debug, Default, Hash))]
-pub struct CandidateCommitments {
+pub struct CandidateCommitments<N = BlockNumber> {
 	/// Messages destined to be interpreted by the Relay chain itself.
 	pub upward_messages: Vec<UpwardMessage>,
+	/// Horizontal messages sent by the parachain.
+	pub horizontal_messages: Vec<OutboundHrmpMessage<Id>>,
 	/// The root of a block's erasure encoding Merkle tree.
 	pub erasure_root: Hash,
 	/// New validation code.
@@ -337,6 +343,8 @@ pub struct CandidateCommitments {
 	pub head_data: HeadData,
 	/// The number of messages processed from the DMQ.
 	pub processed_downward_messages: u32,
+	/// The mark which specifies the block number up to which all inbound HRMP messages are processed.
+	pub hrmp_watermark: N,
 }
 
 impl CandidateCommitments {