pezkuwi-subxt/pallets/xcm/src/lib.rs

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

// Cumulus 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.

// Cumulus 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/>.

//! Pallet for stuff specific to parachains' usage of XCM. Right now that's just the origin
//! used by parachains when receiving `Transact` messages from other parachains or the Relay chain
//! which must be natively represented.

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

use cumulus_primitives_core::ParaId;
use codec::{Encode, Decode};
use sp_runtime::traits::BadOrigin;
pub use pallet::*;

#[frame_support::pallet]
pub mod pallet {
	use frame_support::pallet_prelude::*;
	use frame_system::pallet_prelude::*;

	#[pallet::pallet]
	#[pallet::generate_store(pub(super) trait Store)]
	pub struct Pallet<T>(_);

	/// The module configuration trait.
	#[pallet::config]
	pub trait Config: frame_system::Config {}

	#[pallet::error]
	pub enum Error<T> {}

	#[pallet::hooks]
	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {}

	#[pallet::call]
	impl<T: Config> Pallet<T> {}
}

/// Origin for the parachains module.
#[derive(PartialEq, Eq, Clone, Encode, Decode)]
#[cfg_attr(feature = "std", derive(Debug))]
pub enum Origin {
	/// It comes from the (parent) relay chain.
	Relay,
	/// It comes from a (sibling) parachain.
	SiblingParachain(ParaId),
}

impl From<ParaId> for Origin {
	fn from(id: ParaId) -> Origin {
		Origin::SiblingParachain(id)
	}
}
impl From<u32> for Origin {
	fn from(id: u32) -> Origin {
		Origin::SiblingParachain(id.into())
	}
}

/// Ensure that the origin `o` represents a sibling parachain.
/// Returns `Ok` with the parachain ID of the sibling or an `Err` otherwise.
pub fn ensure_sibling_para<OuterOrigin>(o: OuterOrigin) -> Result<ParaId, BadOrigin>
	where OuterOrigin: Into<Result<Origin, OuterOrigin>>
{
	match o.into() {
		Ok(Origin::SiblingParachain(id)) => Ok(id),
		_ => Err(BadOrigin),
	}
}

/// Ensure that the origin `o` represents is the relay chain.
/// Returns `Ok` if it does or an `Err` otherwise.
pub fn ensure_relay<OuterOrigin>(o: OuterOrigin) -> Result<(), BadOrigin>
	where OuterOrigin: Into<Result<Origin, OuterOrigin>>
{
	match o.into() {
		Ok(Origin::Relay) => Ok(()),
		_ => Err(BadOrigin),
	}
}