pallet_broker/
coretime_interface.rs

1// This file is part of Substrate.
2
3// Copyright (C) Parity Technologies (UK) Ltd.
4// SPDX-License-Identifier: Apache-2.0
5
6// Licensed under the Apache License, Version 2.0 (the "License");
7// you may not use this file except in compliance with the License.
8// You may obtain a copy of the License at
9//
10// 	http://www.apache.org/licenses/LICENSE-2.0
11//
12// Unless required by applicable law or agreed to in writing, software
13// distributed under the License is distributed on an "AS IS" BASIS,
14// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15// See the License for the specific language governing permissions and
16// limitations under the License.
17
18#![deny(missing_docs)]
19
20use alloc::vec::Vec;
21use codec::{Decode, DecodeWithMemTracking, Encode, MaxEncodedLen};
22use core::fmt::Debug;
23use frame_support::Parameter;
24use scale_info::TypeInfo;
25use sp_arithmetic::traits::AtLeast32BitUnsigned;
26use sp_runtime::traits::BlockNumberProvider;
27
28use crate::{CoreIndex, PartsOf57600, TaskId, Timeslice};
29
30/// An element to which a core can be assigned.
31#[derive(
32	Encode,
33	Decode,
34	DecodeWithMemTracking,
35	Clone,
36	Eq,
37	PartialEq,
38	Ord,
39	PartialOrd,
40	Debug,
41	TypeInfo,
42	MaxEncodedLen,
43)]
44pub enum CoreAssignment {
45	/// Core need not be used for anything.
46	Idle,
47	/// Core should be used for the Instantaneous Coretime Pool.
48	Pool,
49	/// Core should be used to process the given task.
50	Task(TaskId),
51}
52
53/// Relay chain block number of `T` that implements [`CoretimeInterface`].
54pub type RCBlockNumberOf<T> = <RCBlockNumberProviderOf<T> as BlockNumberProvider>::BlockNumber;
55
56/// Relay chain block number provider of `T` that implements [`CoretimeInterface`].
57pub type RCBlockNumberProviderOf<T> = <T as CoretimeInterface>::RelayChainBlockNumberProvider;
58
59/// Type able to accept Coretime scheduling instructions and provide certain usage information.
60/// Generally implemented by the Relay-chain or some means of communicating with it.
61///
62/// The trait representation of RFC#5 `<https://github.com/polkadot-fellows/RFCs/pull/5>`.
63pub trait CoretimeInterface {
64	/// A (Relay-chain-side) account ID.
65	type AccountId: Parameter;
66
67	/// A (Relay-chain-side) balance.
68	type Balance: AtLeast32BitUnsigned + Encode + Decode + MaxEncodedLen + TypeInfo + Debug;
69
70	/// A provider for the relay chain block number.
71	type RelayChainBlockNumberProvider: BlockNumberProvider;
72
73	/// Requests the Relay-chain to alter the number of schedulable cores to `count`. Under normal
74	/// operation, the Relay-chain SHOULD send a `notify_core_count(count)` message back.
75	fn request_core_count(count: CoreIndex);
76
77	/// Requests that the Relay-chain send a `notify_revenue` message back at or soon after
78	/// Relay-chain block number `when` whose `until` parameter is equal to `when`.
79	///
80	/// `when` may never be greater than the result of `Self::latest()`.
81	/// The period in to the past which `when` is allowed to be may be limited; if so the limit
82	/// should be understood on a channel outside of this proposal. In the case that the request
83	/// cannot be serviced because `when` is too old a block then a `notify_revenue` message must
84	/// still be returned, but its `revenue` field may be `None`.
85	fn request_revenue_info_at(when: RCBlockNumberOf<Self>);
86
87	/// Instructs the Relay-chain to add the `amount` of DOT to the Instantaneous Coretime Market
88	/// Credit account of `who`.
89	///
90	/// It is expected that Instantaneous Coretime Market Credit on the Relay-chain is NOT
91	/// transferable and only redeemable when used to assign cores in the Instantaneous Coretime
92	/// Pool.
93	fn credit_account(who: Self::AccountId, amount: Self::Balance);
94
95	/// Instructs the Relay-chain to ensure that the core indexed as `core` is utilised for a number
96	/// of assignments in specific ratios given by `assignment` starting as soon after `begin` as
97	/// possible. Core assignments take the form of a `CoreAssignment` value which can either task
98	/// the core to a `ParaId` value or indicate that the core should be used in the Instantaneous
99	/// Pool. Each assignment comes with a ratio value, represented as the numerator of the fraction
100	/// with a denominator of 57,600.
101	///
102	/// If `end_hint` is `Some` and the inner is greater than the current block number, then the
103	/// Relay-chain should optimize in the expectation of receiving a new `assign_core(core, ...)`
104	/// message at or prior to the block number of the inner value. Specific functionality should
105	/// remain unchanged regardless of the `end_hint` value.
106	fn assign_core(
107		core: CoreIndex,
108		begin: RCBlockNumberOf<Self>,
109		assignment: Vec<(CoreAssignment, PartsOf57600)>,
110		end_hint: Option<RCBlockNumberOf<Self>>,
111	);
112
113	/// A hook supposed to be called right after a new timeslice has begun. Likely to be used for
114	/// batching different matters happened during the timeslice that may benefit from batched
115	/// processing.
116	fn on_new_timeslice(_timeslice: Timeslice) {}
117}
118
119impl CoretimeInterface for () {
120	type AccountId = ();
121	type Balance = u64;
122	type RelayChainBlockNumberProvider = ();
123
124	fn request_core_count(_count: CoreIndex) {}
125	fn request_revenue_info_at(_when: RCBlockNumberOf<Self>) {}
126	fn credit_account(_who: Self::AccountId, _amount: Self::Balance) {}
127	fn assign_core(
128		_core: CoreIndex,
129		_begin: RCBlockNumberOf<Self>,
130		_assignment: Vec<(CoreAssignment, PartsOf57600)>,
131		_end_hint: Option<RCBlockNumberOf<Self>>,
132	) {
133	}
134}
pallet_broker/coretime_interface.rs

pallet_broker/
coretime_interface.rs
