pezkuwi-subxt/primitives/core/src/lib.rs

// Copyright 2020-2021 Parity Technologies (UK) Ltd.
// This file is part of Cumulus.

// Substrate is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// Substrate is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with Cumulus.  If not, see <http://www.gnu.org/licenses/>.

//! Cumulus related core primitive types and traits.

#![cfg_attr(not(feature = "std"), no_std)]

use sp_std::prelude::*;
use codec::{Encode, Decode};
use sp_runtime::{RuntimeDebug, traits::Block as BlockT};
use frame_support::weights::Weight;

pub use polkadot_core_primitives::InboundDownwardMessage;
pub use polkadot_parachain::primitives::{Id as ParaId, UpwardMessage, ValidationParams};
pub use polkadot_primitives::v1::{
	PersistedValidationData, AbridgedHostConfiguration, AbridgedHrmpChannel,
};

/// A module that re-exports relevant relay chain definitions.
pub mod relay_chain {
	pub use polkadot_core_primitives::*;
	pub use polkadot_primitives::v1;
	pub use polkadot_primitives::v1::well_known_keys;
}
use relay_chain::BlockNumber as RelayBlockNumber;

/// An inbound HRMP message.
pub type InboundHrmpMessage = polkadot_primitives::v1::InboundHrmpMessage<relay_chain::BlockNumber>;

/// And outbound HRMP message
pub type OutboundHrmpMessage = polkadot_primitives::v1::OutboundHrmpMessage<ParaId>;

/// Error description of a message send failure.
#[derive(Eq, PartialEq, Copy, Clone, RuntimeDebug, Encode, Decode)]
pub enum MessageSendError {
	/// The dispatch queue is full.
	QueueFull,
	/// There does not exist a channel for sending the message.
	NoChannel,
	/// The message is too big to ever fit in a channel.
	TooBig,
	/// Some other error.
	Other,
}

impl From<MessageSendError> for &'static str {
	fn from(e: MessageSendError) -> Self {
		use MessageSendError::*;
		match e {
			QueueFull => "QueueFull",
			NoChannel => "NoChannel",
			TooBig => "TooBig",
			Other => "Other",
		}
	}
}

/// Information about an XCMP channel.
pub struct ChannelInfo {
	/// The maximum number of messages that can be pending in the channel at once.
	pub max_capacity: u32,
	/// The maximum total size of the messages that can be pending in the channel at once.
	pub max_total_size: u32,
	/// The maximum message size that could be put into the channel.
	pub max_message_size: u32,
	/// The current number of messages pending in the channel.
	/// Invariant: should be less or equal to `max_capacity`.s`.
	pub msg_count: u32,
	/// The total size in bytes of all message payloads in the channel.
	/// Invariant: should be less or equal to `max_total_size`.
	pub total_size: u32,
}

pub trait GetChannelInfo {
	fn get_channel_status(id: ParaId) -> ChannelStatus;
	fn get_channel_max(id: ParaId) -> Option<usize>;
}

/// Well known keys for values in the storage.
pub mod well_known_keys {
	/// The storage key for the upward messages.
	///
	/// The upward messages are stored as SCALE encoded `Vec<UpwardMessage>`.
	pub const UPWARD_MESSAGES: &'static [u8] = b":cumulus_upward_messages:";

	/// Code upgarde (set as appropriate by a pallet).
	pub const NEW_VALIDATION_CODE: &'static [u8] = b":cumulus_new_validation_code:";

	/// The storage key with which the runtime passes outbound HRMP messages it wants to send to the
	/// PVF.
	///
	/// The value is stored as SCALE encoded `Vec<OutboundHrmpMessage>`
	pub const HRMP_OUTBOUND_MESSAGES: &'static [u8] = b":cumulus_hrmp_outbound_messages:";

	/// The storage key for communicating the HRMP watermark from the runtime to the PVF. Cleared by
	/// the runtime each block and set after message inclusion, but only if there were messages.
	///
	/// The value is stored as SCALE encoded relay-chain's `BlockNumber`.
	pub const HRMP_WATERMARK: &'static [u8] = b":cumulus_hrmp_watermark:";

	/// The storage key for the processed downward messages.
	///
	/// The value is stored as SCALE encoded `u32`.
	pub const PROCESSED_DOWNWARD_MESSAGES: &'static [u8] = b":cumulus_processed_downward_messages:";
}

/// Something that should be called when a downward message is received.
pub trait DmpMessageHandler {
	/// Handle some incoming DMP messages (note these are individual XCM messages).
	///
	/// Also, process messages up to some `max_weight`.
	fn handle_dmp_messages(
		iter: impl Iterator<Item=(RelayBlockNumber, Vec<u8>)>,
		max_weight: Weight,
	) -> Weight;
}
impl DmpMessageHandler for () {
	fn handle_dmp_messages(
		iter: impl Iterator<Item=(RelayBlockNumber, Vec<u8>)>,
		_max_weight: Weight,
	) -> Weight {
		for _ in iter {}
		0
	}
}

/// Something that should be called for each batch of messages received over XCMP.
pub trait XcmpMessageHandler {
	/// Handle some incoming XCMP messages (note these are the big one-per-block aggregate
	/// messages).
	///
	/// Also, process messages up to some `max_weight`.
	fn handle_xcmp_messages<'a, I: Iterator<Item=(ParaId, RelayBlockNumber, &'a [u8])>>(
		iter: I,
		max_weight: Weight,
	) -> Weight;
}
impl XcmpMessageHandler for () {
	fn handle_xcmp_messages<'a, I: Iterator<Item=(ParaId, RelayBlockNumber, &'a [u8])>>(
		iter: I,
		_max_weight: Weight,
	) -> Weight {
		for _ in iter {}
		0
	}
}

/// Something that should be called when sending an upward message.
pub trait UpwardMessageSender {
	/// Send the given UMP message; return the expected number of blocks before the message will
	/// be dispatched or an error if the message cannot be sent.
	fn send_upward_message(msg: UpwardMessage) -> Result<u32, MessageSendError>;
}
impl UpwardMessageSender for () {
	fn send_upward_message(_msg: UpwardMessage) -> Result<u32, MessageSendError> {
		Err(MessageSendError::NoChannel)
	}
}

/// The status of a channel.
pub enum ChannelStatus {
	/// Channel doesn't exist/has been closed.
	Closed,
	/// Channel is completely full right now.
	Full,
	/// Channel is ready for sending; the two parameters are the maximum size a valid message may
	/// have right now, and the maximum size a message may ever have (this will generally have been
	/// available during message construction, but it's possible the channel parameters changed in
	/// the meantime).
	Ready(usize, usize),
}

/// A means of figuring out what outbound XCMP messages should be being sent.
pub trait XcmpMessageSource {
	/// Take a single XCMP message from the queue for the given `dest`, if one exists.
	fn take_outbound_messages(
		maximum_channels: usize,
	) -> Vec<(ParaId, Vec<u8>)>;
}

impl XcmpMessageSource for () {
	fn take_outbound_messages(
		_maximum_channels: usize,
	) -> Vec<(ParaId, Vec<u8>)> { vec![] }
}

/// The "quality of service" considerations for message sending.
#[derive(Eq, PartialEq, Clone, Copy, Encode, Decode, RuntimeDebug)]
pub enum ServiceQuality {
	/// Ensure that this message is dispatched in the same relative order as any other messages that
	/// were also sent with `Ordered`. This only guarantees message ordering on the dispatch side,
	/// and not necessarily on the execution side.
	Ordered,
	/// Ensure that the message is dispatched as soon as possible, which could result in it being
	/// dispatched before other messages which are larger and/or rely on relative ordering.
	Fast,
}

/// A trait which is called when the validation data is set.
#[impl_trait_for_tuples::impl_for_tuples(30)]
pub trait OnValidationData {
	fn on_validation_data(data: &PersistedValidationData);
}

/// The parachain block that is created by a collator.
///
/// This is send as PoV (proof of validity block) to the relay-chain validators. There it will be
/// passed to the parachain validation Wasm blob to be validated.
#[derive(codec::Encode, codec::Decode)]
pub struct ParachainBlockData<B: BlockT> {
	/// The header of the parachain block.
	header: B::Header,
	/// The extrinsics of the parachain block.
	extrinsics: sp_std::vec::Vec<B::Extrinsic>,
	/// The data that is required to emulate the storage accesses executed by all extrinsics.
	storage_proof: sp_trie::StorageProof,
}

impl<B: BlockT> ParachainBlockData<B> {
	/// Creates a new instance of `Self`.
	pub fn new(
		header: <B as BlockT>::Header,
		extrinsics: sp_std::vec::Vec<<B as BlockT>::Extrinsic>,
		storage_proof: sp_trie::StorageProof,
	) -> Self {
		Self {
			header,
			extrinsics,
			storage_proof,
		}
	}

	/// Convert `self` into the stored header.
	pub fn into_header(self) -> B::Header {
		self.header
	}

	/// Returns the header.
	pub fn header(&self) -> &B::Header {
		&self.header
	}

	/// Returns the extrinsics.
	pub fn extrinsics(&self) -> &[B::Extrinsic] {
		&self.extrinsics
	}

	/// Returns the [`StorageProof`](sp_trie::StorageProof).
	pub fn storage_proof(&self) -> &sp_trie::StorageProof {
		&self.storage_proof
	}

	/// Deconstruct into the inner parts.
	pub fn deconstruct(self) -> (B::Header, sp_std::vec::Vec<B::Extrinsic>, sp_trie::StorageProof) {
		(self.header, self.extrinsics, self.storage_proof)
	}
}