Backport sp-staking from polkadot-0.9.36

Author: khssnv

Cargo.lock

@@ -181,6 +181,7 @@ members = [
 	"primitives/serializer",
 	"primitives/session",
 	"primitives/staking",
+	"primitives/staking-backport",
 	"primitives/state-machine",
 	"primitives/std",
 	"primitives/storage",

Cargo.toml

@@ -0,0 +1,29 @@
+[package]
+name = "sp-staking-backport"
+version = "4.0.0-dev"
+authors = ["Parity Technologies <[email protected]>"]
+edition = "2021"
+license = "Apache-2.0"
+homepage = "https://substrate.io"
+repository = "https://github.com/paritytech/substrate/"
+description = "A crate which contains primitives that are useful for implementation that uses staking approaches in general. Definitions related to sessions, slashing, etc go here."
+readme = "README.md"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.0.0", default-features = false, features = ["derive"] }
+scale-info = { version = "2.0.1", default-features = false, features = ["derive"] }
+sp-core = { version = "6.0.0", default-features = false, path = "../core" }
+sp-runtime = { version = "6.0.0", default-features = false, path = "../runtime" }
+sp-std = { version = "4.0.0", default-features = false, path = "../std" }
+
+[features]
+default = ["std"]
+std = [
+	"codec/std",
+	"scale-info/std",
+	"sp-runtime/std",
+	"sp-std/std",
+]

primitives/staking-backport/Cargo.toml

@@ -0,0 +1,4 @@
+A crate which contains primitives that are useful for implementation that uses staking
+approaches in general. Definitions related to sessions, slashing, etc go here.
+
+License: Apache-2.0

primitives/staking-backport/README.md

@@ -0,0 +1,194 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2019-2022 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#![cfg_attr(not(feature = "std"), no_std)]
+
+//! A crate which contains primitives that are useful for implementation that uses staking
+//! approaches in general. Definitions related to sessions, slashing, etc go here.
+
+use sp_runtime::{DispatchError, DispatchResult};
+use sp_std::{collections::btree_map::BTreeMap, vec::Vec};
+
+pub mod offence;
+
+/// Simple index type with which we can count sessions.
+pub type SessionIndex = u32;
+
+/// Counter for the number of eras that have passed.
+pub type EraIndex = u32;
+
+/// Trait describing something2 that implements a hook for any operations to perform when a staker is
+/// slashed.
+pub trait OnStakerSlash<AccountId, Balance> {
+	/// A hook for any operations to perform when a staker is slashed.
+	///
+	/// # Arguments
+	///
+	/// * `stash` - The stash of the staker whom the slash was applied to.
+	/// * `slashed_active` - The new bonded balance of the staker after the slash was applied.
+	/// * `slashed_unlocking` - A map of slashed eras, and the balance of that unlocking chunk after
+	///   the slash is applied. Any era not present in the map is not affected at all.
+	fn on_slash(
+		stash: &AccountId,
+		slashed_active: Balance,
+		slashed_unlocking: &BTreeMap<EraIndex, Balance>,
+	);
+}
+
+impl<AccountId, Balance> OnStakerSlash<AccountId, Balance> for () {
+	fn on_slash(_: &AccountId, _: Balance, _: &BTreeMap<EraIndex, Balance>) {
+		// Nothing to do here
+	}
+}
+
+/// A struct that reflects stake that an account has in the staking system. Provides a set of
+/// methods to operate on it's properties. Aimed at making `StakingInterface` more concise.
+pub struct Stake<T: StakingInterface + ?Sized> {
+	/// The stash account whose balance is actually locked and at stake.
+	pub stash: T::AccountId,
+	/// The total stake that `stash` has in the staking system. This includes the
+	/// `active` stake, and any funds currently in the process of unbonding via
+	/// [`StakingInterface::unbond`].
+	///
+	/// # Note
+	///
+	/// This is only guaranteed to reflect the amount locked by the staking system. If there are
+	/// non-staking locks on the bonded pair's balance this amount is going to be larger in
+	/// reality.
+	pub total: T::Balance,
+	/// The total amount of the stash's balance that will be at stake in any forthcoming
+	/// rounds.
+	pub active: T::Balance,
+}
+
+/// A generic representation of a staking implementation.
+///
+/// This interface uses the terminology of NPoS, but it is aims to be generic enough to cover other
+/// implementations as well.
+pub trait StakingInterface {
+	/// Balance type used by the staking system.
+	type Balance: PartialEq;
+
+	/// AccountId type used by the staking system
+	type AccountId;
+
+	/// The minimum amount required to bond in order to set nomination intentions. This does not
+	/// necessarily mean the nomination will be counted in an election, but instead just enough to
+	/// be stored as a nominator. In other words, this is the minimum amount to register the
+	/// intention to nominate.
+	fn minimum_nominator_bond() -> Self::Balance;
+
+	/// The minimum amount required to bond in order to set validation intentions.
+	fn minimum_validator_bond() -> Self::Balance;
+
+	/// Return a stash account that is controlled by a `controller`.
+	///
+	/// ## Note
+	///
+	/// The controller abstraction is not permanent and might go away. Avoid using this as much as
+	/// possible.
+	fn stash_by_ctrl(controller: &Self::AccountId) -> Result<Self::AccountId, DispatchError>;
+
+	/// Number of eras that staked funds must remain bonded for.
+	fn bonding_duration() -> EraIndex;
+
+	/// The current era index.
+	///
+	/// This should be the latest planned era that the staking system knows about.
+	fn current_era() -> EraIndex;
+
+	/// Returns the stake of `who`.
+	fn stake(who: &Self::AccountId) -> Result<Stake<Self>, DispatchError>;
+
+	fn total_stake(who: &Self::AccountId) -> Result<Self::Balance, DispatchError> {
+		Self::stake(who).map(|s| s.total)
+	}
+
+	fn active_stake(who: &Self::AccountId) -> Result<Self::Balance, DispatchError> {
+		Self::stake(who).map(|s| s.active)
+	}
+
+	fn is_unbonding(who: &Self::AccountId) -> Result<bool, DispatchError> {
+		Self::stake(who).map(|s| s.active != s.total)
+	}
+
+	fn fully_unbond(who: &Self::AccountId) -> DispatchResult {
+		Self::unbond(who, Self::stake(who)?.active)
+	}
+
+	/// Bond (lock) `value` of `who`'s balance, while forwarding any rewards to `payee`.
+	fn bond(who: &Self::AccountId, value: Self::Balance, payee: &Self::AccountId)
+		-> DispatchResult;
+
+	/// Have `who` nominate `validators`.
+	fn nominate(who: &Self::AccountId, validators: Vec<Self::AccountId>) -> DispatchResult;
+
+	/// Chill `who`.
+	fn chill(who: &Self::AccountId) -> DispatchResult;
+
+	/// Bond some extra amount in `who`'s free balance against the active bonded balance of
+	/// the account. The amount extra actually bonded will never be more than `who`'s free
+	/// balance.
+	fn bond_extra(who: &Self::AccountId, extra: Self::Balance) -> DispatchResult;
+
+	/// Schedule a portion of the active bonded balance to be unlocked at era
+	/// [Self::current_era] + [`Self::bonding_duration`].
+	///
+	/// Once the unlock era has been reached, [`Self::withdraw_unbonded`] can be called to unlock
+	/// the funds.
+	///
+	/// The amount of times this can be successfully called is limited based on how many distinct
+	/// eras funds are schedule to unlock in. Calling [`Self::withdraw_unbonded`] after some unlock
+	/// schedules have reached their unlocking era should allow more calls to this function.
+	fn unbond(stash: &Self::AccountId, value: Self::Balance) -> DispatchResult;
+
+	/// Unlock any funds schedule to unlock before or at the current era.
+	///
+	/// Returns whether the stash was killed because of this withdraw or not.
+	fn withdraw_unbonded(
+		stash: Self::AccountId,
+		num_slashing_spans: u32,
+	) -> Result<bool, DispatchError>;
+
+	/// The ideal number of active validators.
+	fn desired_validator_count() -> u32;
+
+	/// Whether or not there is an ongoing election.
+	fn election_ongoing() -> bool;
+
+	/// Force a current staker to become completely unstaked, immediately.
+	fn force_unstake(who: Self::AccountId) -> DispatchResult;
+
+	/// Checks whether an account `staker` has been exposed in an era.
+	fn is_exposed_in_era(who: &Self::AccountId, era: &EraIndex) -> bool;
+
+	/// Get the nominations of a stash, if they are a nominator, `None` otherwise.
+	#[cfg(feature = "runtime-benchmarks")]
+	fn nominations(who: Self::AccountId) -> Option<Vec<Self::AccountId>>;
+
+	#[cfg(feature = "runtime-benchmarks")]
+	fn add_era_stakers(
+		current_era: &EraIndex,
+		stash: &Self::AccountId,
+		exposures: Vec<(Self::AccountId, Self::Balance)>,
+	);
+
+	#[cfg(feature = "runtime-benchmarks")]
+	fn set_current_era(era: EraIndex);
+}
+
+// sp_core::generate_feature_enabled_macro!(runtime_benchmarks_enabled, feature = "runtime-benchmarks", $);