orml_xcm_mock_message_queue/
lib.rs

1//! # Mock Message Queue for XCM Simulator tests
2
3#![cfg_attr(not(feature = "std"), no_std)]
4
5use cumulus_primitives_core::{ParaId, XcmpMessageFormat, XcmpMessageHandler};
6use frame_support::pallet_prelude::*;
7use parity_scale_codec::{Decode, Encode};
8use polkadot_parachain_primitives::primitives::DmpMessageHandler;
9use sp_std::prelude::*;
10use xcm::{
11	v5::{prelude::*, Weight},
12	VersionedXcm,
13};
14
15pub use module::*;
16
17#[frame_support::pallet]
18pub mod module {
19	use super::*;
20
21	type RelayBlockNumber = u32;
22
23	#[pallet::config]
24	pub trait Config: frame_system::Config {
25		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
26		type XcmExecutor: ExecuteXcm<Self::RuntimeCall>;
27	}
28
29	#[pallet::call]
30	impl<T: Config> Pallet<T> {}
31
32	#[pallet::pallet]
33	#[pallet::without_storage_info]
34	pub struct Pallet<T>(_);
35
36	#[pallet::storage]
37	#[pallet::getter(fn parachain_id)]
38	pub(super) type ParachainId<T: Config> = StorageValue<_, ParaId, ValueQuery>;
39
40	#[pallet::storage]
41	#[pallet::getter(fn received_dmp)]
42	/// A queue of received DMP messages
43	pub(super) type ReceivedDmp<T: Config> = StorageValue<_, Vec<Xcm<T::RuntimeCall>>, ValueQuery>;
44
45	impl<T: Config> Get<ParaId> for Pallet<T> {
46		fn get() -> ParaId {
47			Self::parachain_id()
48		}
49	}
50
51	pub type MessageId = [u8; 32];
52
53	#[pallet::event]
54	#[pallet::generate_deposit(pub(super) fn deposit_event)]
55	pub enum Event<T: Config> {
56		// XCMP
57		/// Some XCM was executed OK.
58		Success(Option<T::Hash>),
59		/// Some XCM failed.
60		Fail(Option<T::Hash>, XcmError),
61		/// Bad XCM version used.
62		BadVersion(Option<T::Hash>),
63		/// Bad XCM format used.
64		BadFormat(Option<T::Hash>),
65
66		// DMP
67		/// Downward message is invalid XCM.
68		InvalidFormat(MessageId),
69		/// Downward message is unsupported version of XCM.
70		UnsupportedVersion(MessageId),
71		/// Downward message executed with the given outcome.
72		ExecutedDownward(MessageId, Outcome),
73	}
74
75	impl<T: Config> Pallet<T> {
76		pub fn set_para_id(para_id: ParaId) {
77			ParachainId::<T>::put(para_id);
78		}
79
80		fn handle_xcmp_message(
81			sender: ParaId,
82			_sent_at: RelayBlockNumber,
83			xcm: VersionedXcm<T::RuntimeCall>,
84			max_weight: Weight,
85		) -> Result<Weight, XcmError> {
86			use sp_runtime::traits::Hash;
87			let hash = Encode::using_encoded(&xcm, T::Hashing::hash);
88			let mut message_hash = Encode::using_encoded(&xcm, sp_io::hashing::blake2_256);
89			let (result, event) = match Xcm::<T::RuntimeCall>::try_from(xcm) {
90				Ok(xcm) => {
91					let location = (Parent, Parachain(sender.into()));
92					match T::XcmExecutor::prepare_and_execute(
93						location,
94						xcm,
95						&mut message_hash,
96						max_weight,
97						Weight::zero(),
98					) {
99						Outcome::Error { error } => (Err(error), Event::Fail(Some(hash), error)),
100						Outcome::Complete { used } => (Ok(used), Event::Success(Some(hash))),
101						// As far as the caller is concerned, this was dispatched without error, so
102						// we just report the weight used.
103						Outcome::Incomplete { used, error } => (Ok(used), Event::Fail(Some(hash), error)),
104					}
105				}
106				Err(()) => (Err(XcmError::UnhandledXcmVersion), Event::BadVersion(Some(hash))),
107			};
108			Self::deposit_event(event);
109			result
110		}
111	}
112
113	impl<T: Config> XcmpMessageHandler for Pallet<T> {
114		fn handle_xcmp_messages<'a, I: Iterator<Item = (ParaId, RelayBlockNumber, &'a [u8])>>(
115			iter: I,
116			max_weight: Weight,
117		) -> Weight {
118			for (sender, sent_at, data) in iter {
119				let mut data_ref = data;
120				let _ =
121					XcmpMessageFormat::decode(&mut data_ref).expect("Simulator encodes with versioned xcm format; qed");
122
123				let mut remaining_fragments = data_ref;
124				while !remaining_fragments.is_empty() {
125					if let Ok(xcm) = VersionedXcm::<T::RuntimeCall>::decode(&mut remaining_fragments) {
126						let _ = Self::handle_xcmp_message(sender, sent_at, xcm, max_weight);
127					} else {
128						debug_assert!(false, "Invalid incoming XCMP message data");
129					}
130				}
131			}
132			max_weight
133		}
134	}
135
136	impl<T: Config> DmpMessageHandler for Pallet<T> {
137		fn handle_dmp_messages(iter: impl Iterator<Item = (RelayBlockNumber, Vec<u8>)>, limit: Weight) -> Weight {
138			for (_sent_at, data) in iter {
139				let mut id = sp_io::hashing::blake2_256(&data[..]);
140				let maybe_versioned = VersionedXcm::<T::RuntimeCall>::decode(&mut &data[..]);
141				match maybe_versioned {
142					Err(_) => {
143						Self::deposit_event(Event::InvalidFormat(id));
144					}
145					Ok(versioned) => match Xcm::try_from(versioned) {
146						Err(()) => Self::deposit_event(Event::UnsupportedVersion(id)),
147						Ok(x) => {
148							let outcome =
149								T::XcmExecutor::prepare_and_execute(Parent, x.clone(), &mut id, limit, Weight::zero());
150							<ReceivedDmp<T>>::append(x);
151							Self::deposit_event(Event::ExecutedDownward(id, outcome));
152						}
153					},
154				}
155			}
156			limit
157		}
158	}
159}
orml_xcm_mock_message_queue/lib.rs

orml_xcm_mock_message_queue/
lib.rs
