Downward & Upward messages (#1266)

* Downward messages, the front-end.

* Move types around to make them accessible from Parachains

* Fix compilation

* Fix branch

* Make it compile for Cumulus

* Update the branch names

* Add default generic parameter

* Implement `Partialeq`

* Move upward messages into the `ValidationResult`

* Support disabling of the runtime api

* Update branch

* Adds support for handling downward messages

* Implement sending XCMP messages as up/downward messages

* service: update to latest ServiceBuilder changes

* Make it compile

* Initial commit

Forked at: ef2aa428d7
Parent branch: origin/master

* Update substrate branch to cecton-update-polkadot-substrate

* Update substrate & polkadot to cumulus-branch

* Reset branch

* Update primitives/src/parachain.rs

Co-authored-by: Robert Habermeier <rphmeier@gmail.com>

* Update runtime/common/src/parachains.rs

Co-authored-by: Robert Habermeier <rphmeier@gmail.com>

* Update runtime/common/src/parachains.rs

Co-authored-by: Robert Habermeier <rphmeier@gmail.com>

* Minor fixes

* Fix wasm build

Co-authored-by: Gav Wood <gavin@parity.io>
Co-authored-by: André Silva <andre.beat@gmail.com>
Co-authored-by: Cecile Tonglet <cecile.tonglet@cecton.com>
Co-authored-by: Robert Habermeier <rphmeier@gmail.com>

polkadot/parachain/src/primitives.rs

@@ -28,9 +28,8 @@ use serde::{Serialize, Deserialize};
 #[cfg(feature = "std")]
 use sp_core::bytes;
 
-/// The block number of the relay chain.
-/// 32-bits will allow for 136 years of blocks assuming 1 block per second.
-pub type RelayChainBlockNumber = u32;
+/// Block number type used by the relay chain.
+pub use polkadot_core_primitives::BlockNumber as RelayChainBlockNumber;
 
 /// Parachain head data included in the chain.
 #[derive(PartialEq, Eq, Clone, PartialOrd, Ord, Encode, Decode, RuntimeDebug)]
@@ -186,10 +185,6 @@ impl sp_std::convert::TryFrom<u8> for ParachainDispatchOrigin {
 
 /// A message from a parachain to its Relay Chain.
 #[derive(Clone, PartialEq, Eq, Encode, Decode)]
-#[cfg_attr(
-	any(feature = "std", feature = "wasm-api"),
-	derive(sp_runtime_interface::pass_by::PassByCodec,
-))]
 #[cfg_attr(feature = "std", derive(Debug))]
 pub struct UpwardMessage {
 	/// The origin for the message to be sent from.
@@ -212,13 +207,13 @@ pub struct ValidationParams {
 	/// The maximum head-data size permitted, in bytes.
 	pub max_head_data_size: u32,
 	/// The current relay-chain block number.
-	pub relay_chain_height: RelayChainBlockNumber,
+	pub relay_chain_height: polkadot_core_primitives::BlockNumber,
 	/// Whether a code upgrade is allowed or not, and at which height the upgrade
 	/// would be applied after, if so. The parachain logic should apply any upgrade
 	/// issued in this block after the first block
 	/// with `relay_chain_height` at least this value, if `Some`. if `None`, issue
 	/// no upgrade.
-	pub code_upgrade_allowed: Option<RelayChainBlockNumber>,
+	pub code_upgrade_allowed: Option<polkadot_core_primitives::BlockNumber>,
 }
 
 /// The result of parachain validation.
@@ -230,4 +225,10 @@ pub struct ValidationResult {
 	pub head_data: HeadData,
 	/// An update to the validation code that should be scheduled in the relay chain.
 	pub new_validation_code: Option<ValidationCode>,
+	/// Upward messages send by the Parachain.
+	pub upward_messages: Vec<UpwardMessage>,
+	/// 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,
 }