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// This file is part of Substrate.
// Copyright (C) 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.
//! # Nomination Pools for Staking Delegation
//!
//! A pallet that allows members to delegate their stake to nominating pools. A nomination pool acts
//! as nominator and nominates validators on the members behalf.
//!
//! # Index
//!
//! * [Key terms](#key-terms)
//! * [Usage](#usage)
//! * [Implementor's Guide](#implementors-guide)
//! * [Design](#design)
//!
//! ## Key Terms
//!
//! * pool id: A unique identifier of each pool. Set to u32.
//! * bonded pool: Tracks the distribution of actively staked funds. See [`BondedPool`] and
//! [`BondedPoolInner`].
//! * reward pool: Tracks rewards earned by actively staked funds. See [`RewardPool`] and
//! [`RewardPools`].
//! * unbonding sub pools: Collection of pools at different phases of the unbonding lifecycle. See
//! [`SubPools`] and [`SubPoolsStorage`].
//! * members: Accounts that are members of pools. See [`PoolMember`] and [`PoolMembers`].
//! * roles: Administrative roles of each pool, capable of controlling nomination, and the state of
//! the pool.
//! * point: A unit of measure for a members portion of a pool's funds. Points initially have a
//! ratio of 1 (as set by `POINTS_TO_BALANCE_INIT_RATIO`) to balance, but as slashing happens,
//! this can change.
//! * kick: The act of a pool administrator forcibly ejecting a member.
//! * bonded account: A key-less account id derived from the pool id that acts as the bonded
//! account. This account registers itself as a nominator in the staking system, and follows
//! exactly the same rules and conditions as a normal staker. Its bond increases or decreases as
//! members join, it can `nominate` or `chill`, and might not even earn staking rewards if it is
//! not nominating proper validators.
//! * reward account: A similar key-less account, that is set as the `Payee` account for the bonded
//! account for all staking rewards.
//! * change rate: The rate at which pool commission can be changed. A change rate consists of a
//! `max_increase` and `min_delay`, dictating the maximum percentage increase that can be applied
//! to the commission per number of blocks.
//! * throttle: An attempted commission increase is throttled if the attempted change falls outside
//! the change rate bounds.
//!
//! ## Usage
//!
//! ### Join
//!
//! An account can stake funds with a nomination pool by calling [`Call::join`].
//!
//! ### Claim rewards
//!
//! After joining a pool, a member can claim rewards by calling [`Call::claim_payout`].
//!
//! A pool member can also set a `ClaimPermission` with [`Call::set_claim_permission`], to allow
//! other members to permissionlessly bond or withdraw their rewards by calling
//! [`Call::bond_extra_other`] or [`Call::claim_payout_other`] respectively.
//!
//! For design docs see the [reward pool](#reward-pool) section.
//!
//! ### Leave
//!
//! In order to leave, a member must take two steps.
//!
//! First, they must call [`Call::unbond`]. The unbond extrinsic will start the unbonding process by
//! unbonding all or a portion of the members funds.
//!
//! > A member can have up to [`Config::MaxUnbonding`] distinct active unbonding requests.
//!
//! Second, once [`sp_staking::StakingInterface::bonding_duration`] eras have passed, the member can
//! call [`Call::withdraw_unbonded`] to withdraw any funds that are free.
//!
//! For design docs see the [bonded pool](#bonded-pool) and [unbonding sub
//! pools](#unbonding-sub-pools) sections.
//!
//! ### Slashes
//!
//! Slashes are distributed evenly across the bonded pool and the unbonding pools from slash era+1
//! through the slash apply era. Thus, any member who either
//!
//! 1. unbonded, or
//! 2. was actively bonded
//
//! in the aforementioned range of eras will be affected by the slash. A member is slashed pro-rata
//! based on its stake relative to the total slash amount.
//!
//! Slashing does not change any single member's balance. Instead, the slash will only reduce the
//! balance associated with a particular pool. But, we never change the total *points* of a pool
//! because of slashing. Therefore, when a slash happens, the ratio of points to balance changes in
//! a pool. In other words, the value of one point, which is initially 1-to-1 against a unit of
//! balance, is now less than one balance because of the slash.
//!
//! ### Administration
//!
//! A pool can be created with the [`Call::create`] call. Once created, the pools nominator or root
//! user must call [`Call::nominate`] to start nominating. [`Call::nominate`] can be called at
//! anytime to update validator selection.
//!
//! Similar to [`Call::nominate`], [`Call::chill`] will chill to pool in the staking system, and
//! [`Call::pool_withdraw_unbonded`] will withdraw any unbonding chunks of the pool bonded account.
//! The latter call is permissionless and can be called by anyone at any time.
//!
//! To help facilitate pool administration the pool has one of three states (see [`PoolState`]):
//!
//! * Open: Anyone can join the pool and no members can be permissionlessly removed.
//! * Blocked: No members can join and some admin roles can kick members. Kicking is not instant,
//! and follows the same process of `unbond` and then `withdraw_unbonded`. In other words,
//! administrators can permissionlessly unbond other members.
//! * Destroying: No members can join and all members can be permissionlessly removed with
//! [`Call::unbond`] and [`Call::withdraw_unbonded`]. Once a pool is in destroying state, it
//! cannot be reverted to another state.
//!
//! A pool has 4 administrative roles (see [`PoolRoles`]):
//!
//! * Depositor: creates the pool and is the initial member. They can only leave the pool once all
//! other members have left. Once they fully withdraw their funds, the pool is destroyed.
//! * Nominator: can select which validators the pool nominates.
//! * Bouncer: can change the pools state and kick members if the pool is blocked.
//! * Root: can change the nominator, bouncer, or itself, manage and claim commission, and can
//! perform any of the actions the nominator or bouncer can.
//!
//! ### Commission
//!
//! A pool can optionally have a commission configuration, via the `root` role, set with
//! [`Call::set_commission`] and claimed with [`Call::claim_commission`]. A payee account must be
//! supplied with the desired commission percentage. Beyond the commission itself, a pool can have a
//! maximum commission and a change rate.
//!
//! Importantly, both max commission [`Call::set_commission_max`] and change rate
//! [`Call::set_commission_change_rate`] can not be removed once set, and can only be set to more
//! restrictive values (i.e. a lower max commission or a slower change rate) in subsequent updates.
//!
//! If set, a pool's commission is bound to [`GlobalMaxCommission`] at the time it is applied to
//! pending rewards. [`GlobalMaxCommission`] is intended to be updated only via governance.
//!
//! When a pool is dissolved, any outstanding pending commission that has not been claimed will be
//! transferred to the depositor.
//!
//! Implementation note: Commission is analogous to a separate member account of the pool, with its
//! own reward counter in the form of `current_pending_commission`.
//!
//! Crucially, commission is applied to rewards based on the current commission in effect at the
//! time rewards are transferred into the reward pool. This is to prevent the malicious behaviour of
//! changing the commission rate to a very high value after rewards are accumulated, and thus claim
//! an unexpectedly high chunk of the reward.
//!
//! ### Dismantling
//!
//! As noted, a pool is destroyed once
//!
//! 1. First, all members need to fully unbond and withdraw. If the pool state is set to
//! `Destroying`, this can happen permissionlessly.
//! 2. The depositor itself fully unbonds and withdraws.
//!
//! > Note that at this point, based on the requirements of the staking system, the pool's bonded
//! > account's stake might not be able to ge below a certain threshold as a nominator. At this
//! > point, the pool should `chill` itself to allow the depositor to leave. See [`Call::chill`].
//!
//! ## Implementor's Guide
//!
//! Some notes and common mistakes that wallets/apps wishing to implement this pallet should be
//! aware of:
//!
//!
//! ### Pool Members
//!
//! * In general, whenever a pool member changes their total point, the chain will automatically
//! claim all their pending rewards for them. This is not optional, and MUST happen for the reward
//! calculation to remain correct (see the documentation of `bond` as an example). So, make sure
//! you are warning your users about it. They might be surprised if they see that they bonded an
//! extra 100 DOTs, and now suddenly their 5.23 DOTs in pending reward is gone. It is not gone, it
//! has been paid out to you!
//! * Joining a pool implies transferring funds to the pool account. So it might be (based on which
//! wallet that you are using) that you no longer see the funds that are moved to the pool in your
//! “free balance” section. Make sure the user is aware of this, and not surprised by seeing this.
//! Also, the transfer that happens here is configured to to never accidentally destroy the sender
//! account. So to join a Pool, your sender account must remain alive with 1 DOT left in it. This
//! means, with 1 DOT as existential deposit, and 1 DOT as minimum to join a pool, you need at
//! least 2 DOT to join a pool. Consequently, if you are suggesting members to join a pool with
//! “Maximum possible value”, you must subtract 1 DOT to remain in the sender account to not
//! accidentally kill it.
//! * Points and balance are not the same! Any pool member, at any point in time, can have points in
//! either the bonded pool or any of the unbonding pools. The crucial fact is that in any of these
//! pools, the ratio of point to balance is different and might not be 1. Each pool starts with a
//! ratio of 1, but as time goes on, for reasons such as slashing, the ratio gets broken. Over
//! time, 100 points in a bonded pool can be worth 90 DOTs. Make sure you are either representing
//! points as points (not as DOTs), or even better, always display both: “You have x points in
//! pool y which is worth z DOTs”. See here and here for examples of how to calculate point to
//! balance ratio of each pool (it is almost trivial ;))
//!
//! ### Pool Management
//!
//! * The pool will be seen from the perspective of the rest of the system as a single nominator.
//! Ergo, This nominator must always respect the `staking.minNominatorBond` limit. Similar to a
//! normal nominator, who has to first `chill` before fully unbonding, the pool must also do the
//! same. The pool’s bonded account will be fully unbonded only when the depositor wants to leave
//! and dismantle the pool. All that said, the message is: the depositor can only leave the chain
//! when they chill the pool first.
//!
//! ## Design
//!
//! _Notes_: this section uses pseudo code to explain general design and does not necessarily
//! reflect the exact implementation. Additionally, a working knowledge of `pallet-staking`'s api is
//! assumed.
//!
//! ### Goals
//!
//! * Maintain network security by upholding integrity of slashing events, sufficiently penalizing
//! members that where in the pool while it was backing a validator that got slashed.
//! * Maximize scalability in terms of member count.
//!
//! In order to maintain scalability, all operations are independent of the number of members. To do
//! this, delegation specific information is stored local to the member while the pool data
//! structures have bounded datum.
//!
//! ### Bonded pool
//!
//! A bonded pool nominates with its total balance, excluding that which has been withdrawn for
//! unbonding. The total points of a bonded pool are always equal to the sum of points of the
//! delegation members. A bonded pool tracks its points and reads its bonded balance.
//!
//! When a member joins a pool, `amount_transferred` is transferred from the members account to the
//! bonded pools account. Then the pool calls `staking::bond_extra(amount_transferred)` and issues
//! new points which are tracked by the member and added to the bonded pool's points.
//!
//! When the pool already has some balance, we want the value of a point before the transfer to
//! equal the value of a point after the transfer. So, when a member joins a bonded pool with a
//! given `amount_transferred`, we maintain the ratio of bonded balance to points such that:
//!
//! ```text
//! balance_after_transfer / points_after_transfer == balance_before_transfer / points_before_transfer;
//! ```
//!
//! To achieve this, we issue points based on the following:
//!
//! ```text
//! points_issued = (points_before_transfer / balance_before_transfer) * amount_transferred;
//! ```
//!
//! For new bonded pools we can set the points issued per balance arbitrarily. In this
//! implementation we use a 1 points to 1 balance ratio for pool creation (see
//! [`POINTS_TO_BALANCE_INIT_RATIO`]).
//!
//! **Relevant extrinsics:**
//!
//! * [`Call::create`]
//! * [`Call::join`]
//!
//! ### Reward pool
//!
//! When a pool is first bonded it sets up a deterministic, inaccessible account as its reward
//! destination. This reward account combined with `RewardPool` compose a reward pool.
//!
//! Reward pools are completely separate entities to bonded pools. Along with its account, a reward
//! pool also tracks its outstanding and claimed rewards as counters, in addition to pending and
//! claimed commission. These counters are updated with `RewardPool::update_records`. The current
//! reward counter of the pool (the total outstanding rewards, in points) is also callable with the
//! `RewardPool::current_reward_counter` method.
//!
//! See [this link](https://hackmd.io/PFGn6wI5TbCmBYoEA_f2Uw) for an in-depth explanation of the
//! reward pool mechanism.
//!
//! **Relevant extrinsics:**
//!
//! * [`Call::claim_payout`]
//!
//! ### Unbonding sub pools
//!
//! When a member unbonds, it's balance is unbonded in the bonded pool's account and tracked in an
//! unbonding pool associated with the active era. If no such pool exists, one is created. To track
//! which unbonding sub pool a member belongs too, a member tracks it's `unbonding_era`.
//!
//! When a member initiates unbonding it's claim on the bonded pool (`balance_to_unbond`) is
//! computed as:
//!
//! ```text
//! balance_to_unbond = (bonded_pool.balance / bonded_pool.points) * member.points;
//! ```
//!
//! If this is the first transfer into an unbonding pool arbitrary amount of points can be issued
//! per balance. In this implementation unbonding pools are initialized with a 1 point to 1 balance
//! ratio (see [`POINTS_TO_BALANCE_INIT_RATIO`]). Otherwise, the unbonding pools hold the same
//! points to balance ratio properties as the bonded pool, so member points in the unbonding pool
//! are issued based on
//!
//! ```text
//! new_points_issued = (points_before_transfer / balance_before_transfer) * balance_to_unbond;
//! ```
//!
//! For scalability, a bound is maintained on the number of unbonding sub pools (see
//! [`TotalUnbondingPools`]). An unbonding pool is removed once its older than `current_era -
//! TotalUnbondingPools`. An unbonding pool is merged into the unbonded pool with
//!
//! ```text
//! unbounded_pool.balance = unbounded_pool.balance + unbonding_pool.balance;
//! unbounded_pool.points = unbounded_pool.points + unbonding_pool.points;
//! ```
//!
//! This scheme "averages" out the points value in the unbonded pool.
//!
//! Once a members `unbonding_era` is older than `current_era -
//! [sp_staking::StakingInterface::bonding_duration]`, it can can cash it's points out of the
//! corresponding unbonding pool. If it's `unbonding_era` is older than `current_era -
//! TotalUnbondingPools`, it can cash it's points from the unbonded pool.
//!
//! **Relevant extrinsics:**
//!
//! * [`Call::unbond`]
//! * [`Call::withdraw_unbonded`]
//!
//! ### Slashing
//!
//! This section assumes that the slash computation is executed by
//! `pallet_staking::StakingLedger::slash`, which passes the information to this pallet via
//! [`sp_staking::OnStakingUpdate::on_slash`].
//!
//! Unbonding pools need to be slashed to ensure all nominators whom where in the bonded pool while
//! it was backing a validator that equivocated are punished. Without these measures a member could
//! unbond right after a validator equivocated with no consequences.
//!
//! This strategy is unfair to members who joined after the slash, because they get slashed as well,
//! but spares members who unbond. The latter is much more important for security: if a pool's
//! validators are attacking the network, their members need to unbond fast! Avoiding slashes gives
//! them an incentive to do that if validators get repeatedly slashed.
//!
//! To be fair to joiners, this implementation also need joining pools, which are actively staking,
//! in addition to the unbonding pools. For maintenance simplicity these are not implemented.
//! Related: <https://github.com/paritytech/substrate/issues/10860>
//!
//! ### Limitations
//!
//! * PoolMembers cannot vote with their staked funds because they are transferred into the pools
//! account. In the future this can be overcome by allowing the members to vote with their bonded
//! funds via vote splitting.
//! * PoolMembers cannot quickly transfer to another pool if they do no like nominations, instead
//! they must wait for the unbonding duration.
#![cfg_attr(not(feature = "std"), no_std)]
use codec::Codec;
use frame_support::{
defensive, ensure,
pallet_prelude::{MaxEncodedLen, *},
storage::bounded_btree_map::BoundedBTreeMap,
traits::{
Currency, Defensive, DefensiveOption, DefensiveResult, DefensiveSaturating,
ExistenceRequirement, Get,
},
DefaultNoBound, PalletError,
};
use frame_system::pallet_prelude::BlockNumberFor;
use scale_info::TypeInfo;
use sp_core::U256;
use sp_runtime::{
traits::{
AccountIdConversion, Bounded, CheckedAdd, CheckedSub, Convert, Saturating, StaticLookup,
Zero,
},
FixedPointNumber, Perbill,
};
use sp_staking::{EraIndex, StakingInterface};
use sp_std::{collections::btree_map::BTreeMap, fmt::Debug, ops::Div, vec::Vec};
#[cfg(any(feature = "try-runtime", feature = "fuzzing", test, debug_assertions))]
use sp_runtime::TryRuntimeError;
/// The log target of this pallet.
pub const LOG_TARGET: &str = "runtime::nomination-pools";
// syntactic sugar for logging.
#[macro_export]
macro_rules! log {
($level:tt, $patter:expr $(, $values:expr)* $(,)?) => {
log::$level!(
target: $crate::LOG_TARGET,
concat!("[{:?}] 🏊♂️ ", $patter), <frame_system::Pallet<T>>::block_number() $(, $values)*
)
};
}
#[cfg(any(test, feature = "fuzzing"))]
pub mod mock;
#[cfg(test)]
mod tests;
pub mod migration;
pub mod weights;
pub use pallet::*;
pub use weights::WeightInfo;
/// The balance type used by the currency system.
pub type BalanceOf<T> =
<<T as Config>::Currency as Currency<<T as frame_system::Config>::AccountId>>::Balance;
/// Type used for unique identifier of each pool.
pub type PoolId = u32;
type AccountIdLookupOf<T> = <<T as frame_system::Config>::Lookup as StaticLookup>::Source;
pub const POINTS_TO_BALANCE_INIT_RATIO: u32 = 1;
/// Possible operations on the configuration values of this pallet.
#[derive(Encode, Decode, MaxEncodedLen, TypeInfo, RuntimeDebugNoBound, PartialEq, Clone)]
pub enum ConfigOp<T: Codec + Debug> {
/// Don't change.
Noop,
/// Set the given value.
Set(T),
/// Remove from storage.
Remove,
}
/// The type of bonding that can happen to a pool.
enum BondType {
/// Someone is bonding into the pool upon creation.
Create,
/// Someone is adding more funds later to this pool.
Later,
}
/// How to increase the bond of a member.
#[derive(Encode, Decode, Clone, Copy, Debug, PartialEq, Eq, TypeInfo)]
pub enum BondExtra<Balance> {
/// Take from the free balance.
FreeBalance(Balance),
/// Take the entire amount from the accumulated rewards.
Rewards,
}
/// The type of account being created.
#[derive(Encode, Decode)]
enum AccountType {
Bonded,
Reward,
}
/// The permission a pool member can set for other accounts to claim rewards on their behalf.
#[derive(Encode, Decode, MaxEncodedLen, Clone, Copy, Debug, PartialEq, Eq, TypeInfo)]
pub enum ClaimPermission {
/// Only the pool member themself can claim their rewards.
Permissioned,
/// Anyone can compound rewards on a pool member's behalf.
PermissionlessCompound,
/// Anyone can withdraw rewards on a pool member's behalf.
PermissionlessWithdraw,
/// Anyone can withdraw and compound rewards on a member's behalf.
PermissionlessAll,
}
impl ClaimPermission {
fn can_bond_extra(&self) -> bool {
matches!(self, ClaimPermission::PermissionlessAll | ClaimPermission::PermissionlessCompound)
}
fn can_claim_payout(&self) -> bool {
matches!(self, ClaimPermission::PermissionlessAll | ClaimPermission::PermissionlessWithdraw)
}
}
impl Default for ClaimPermission {
fn default() -> Self {
Self::Permissioned
}
}
/// A member in a pool.
#[derive(Encode, Decode, MaxEncodedLen, TypeInfo, RuntimeDebugNoBound, CloneNoBound)]
#[cfg_attr(feature = "std", derive(frame_support::PartialEqNoBound, DefaultNoBound))]
#[codec(mel_bound(T: Config))]
#[scale_info(skip_type_params(T))]
pub struct PoolMember<T: Config> {
/// The identifier of the pool to which `who` belongs.
pub pool_id: PoolId,
/// The quantity of points this member has in the bonded pool or in a sub pool if
/// `Self::unbonding_era` is some.
pub points: BalanceOf<T>,
/// The reward counter at the time of this member's last payout claim.
pub last_recorded_reward_counter: T::RewardCounter,
/// The eras in which this member is unbonding, mapped from era index to the number of
/// points scheduled to unbond in the given era.
pub unbonding_eras: BoundedBTreeMap<EraIndex, BalanceOf<T>, T::MaxUnbonding>,
}
impl<T: Config> PoolMember<T> {
/// The pending rewards of this member.
fn pending_rewards(
&self,
current_reward_counter: T::RewardCounter,
) -> Result<BalanceOf<T>, Error<T>> {
// accuracy note: Reward counters are `FixedU128` with base of 10^18. This value is being
// multiplied by a point. The worse case of a point is 10x the granularity of the balance
// (10x is the common configuration of `MaxPointsToBalance`).
//
// Assuming roughly the current issuance of polkadot (12,047,781,394,999,601,455, which is
// 1.2 * 10^9 * 10^10 = 1.2 * 10^19), the worse case point value is around 10^20.
//
// The final multiplication is:
//
// rc * 10^20 / 10^18 = rc * 100
//
// the implementation of `multiply_by_rational_with_rounding` shows that it will only fail
// if the final division is not enough to fit in u128. In other words, if `rc * 100` is more
// than u128::max. Given that RC is interpreted as reward per unit of point, and unit of
// point is equal to balance (normally), and rewards are usually a proportion of the points
// in the pool, the likelihood of rc reaching near u128::MAX is near impossible.
(current_reward_counter.defensive_saturating_sub(self.last_recorded_reward_counter))
.checked_mul_int(self.active_points())
.ok_or(Error::<T>::OverflowRisk)
}
/// Active balance of the member.
///
/// This is derived from the ratio of points in the pool to which the member belongs to.
/// Might return different values based on the pool state for the same member and points.
fn active_balance(&self) -> BalanceOf<T> {
if let Some(pool) = BondedPool::<T>::get(self.pool_id).defensive() {
pool.points_to_balance(self.points)
} else {
Zero::zero()
}
}
/// Total points of this member, both active and unbonding.
fn total_points(&self) -> BalanceOf<T> {
self.active_points().saturating_add(self.unbonding_points())
}
/// Active points of the member.
fn active_points(&self) -> BalanceOf<T> {
self.points
}
/// Inactive points of the member, waiting to be withdrawn.
fn unbonding_points(&self) -> BalanceOf<T> {
self.unbonding_eras
.as_ref()
.iter()
.fold(BalanceOf::<T>::zero(), |acc, (_, v)| acc.saturating_add(*v))
}
/// Try and unbond `points_dissolved` from self, and in return mint `points_issued` into the
/// corresponding `era`'s unlock schedule.
///
/// In the absence of slashing, these two points are always the same. In the presence of
/// slashing, the value of points in different pools varies.
///
/// Returns `Ok(())` and updates `unbonding_eras` and `points` if success, `Err(_)` otherwise.
fn try_unbond(
&mut self,
points_dissolved: BalanceOf<T>,
points_issued: BalanceOf<T>,
unbonding_era: EraIndex,
) -> Result<(), Error<T>> {
if let Some(new_points) = self.points.checked_sub(&points_dissolved) {
match self.unbonding_eras.get_mut(&unbonding_era) {
Some(already_unbonding_points) =>
*already_unbonding_points =
already_unbonding_points.saturating_add(points_issued),
None => self
.unbonding_eras
.try_insert(unbonding_era, points_issued)
.map(|old| {
if old.is_some() {
defensive!("value checked to not exist in the map; qed");
}
})
.map_err(|_| Error::<T>::MaxUnbondingLimit)?,
}
self.points = new_points;
Ok(())
} else {
Err(Error::<T>::MinimumBondNotMet)
}
}
/// Withdraw any funds in [`Self::unbonding_eras`] who's deadline in reached and is fully
/// unlocked.
///
/// Returns a a subset of [`Self::unbonding_eras`] that got withdrawn.
///
/// Infallible, noop if no unbonding eras exist.
fn withdraw_unlocked(
&mut self,
current_era: EraIndex,
) -> BoundedBTreeMap<EraIndex, BalanceOf<T>, T::MaxUnbonding> {
// NOTE: if only drain-filter was stable..
let mut removed_points =
BoundedBTreeMap::<EraIndex, BalanceOf<T>, T::MaxUnbonding>::default();
self.unbonding_eras.retain(|e, p| {
if *e > current_era {
true
} else {
removed_points
.try_insert(*e, *p)
.expect("source map is bounded, this is a subset, will be bounded; qed");
false
}
});
removed_points
}
}
/// A pool's possible states.
#[derive(Encode, Decode, MaxEncodedLen, TypeInfo, PartialEq, RuntimeDebugNoBound, Clone, Copy)]
pub enum PoolState {
/// The pool is open to be joined, and is working normally.
Open,
/// The pool is blocked. No one else can join.
Blocked,
/// The pool is in the process of being destroyed.
///
/// All members can now be permissionlessly unbonded, and the pool can never go back to any
/// other state other than being dissolved.
Destroying,
}
/// Pool administration roles.
///
/// Any pool has a depositor, which can never change. But, all the other roles are optional, and
/// cannot exist. Note that if `root` is set to `None`, it basically means that the roles of this
/// pool can never change again (except via governance).
#[derive(Encode, Decode, MaxEncodedLen, TypeInfo, Debug, PartialEq, Clone)]
pub struct PoolRoles<AccountId> {
/// Creates the pool and is the initial member. They can only leave the pool once all other
/// members have left. Once they fully leave, the pool is destroyed.
pub depositor: AccountId,
/// Can change the nominator, bouncer, or itself and can perform any of the actions the
/// nominator or bouncer can.
pub root: Option<AccountId>,
/// Can select which validators the pool nominates.
pub nominator: Option<AccountId>,
/// Can change the pools state and kick members if the pool is blocked.
pub bouncer: Option<AccountId>,
}
/// Pool commission.
///
/// The pool `root` can set commission configuration after pool creation. By default, all commission
/// values are `None`. Pool `root` can also set `max` and `change_rate` configurations before
/// setting an initial `current` commission.
///
/// `current` is a tuple of the commission percentage and payee of commission. `throttle_from`
/// keeps track of which block `current` was last updated. A `max` commission value can only be
/// decreased after the initial value is set, to prevent commission from repeatedly increasing.
///
/// An optional commission `change_rate` allows the pool to set strict limits to how much commission
/// can change in each update, and how often updates can take place.
#[derive(
Encode, Decode, DefaultNoBound, MaxEncodedLen, TypeInfo, DebugNoBound, PartialEq, Copy, Clone,
)]
#[codec(mel_bound(T: Config))]
#[scale_info(skip_type_params(T))]
pub struct Commission<T: Config> {
/// Optional commission rate of the pool along with the account commission is paid to.
pub current: Option<(Perbill, T::AccountId)>,
/// Optional maximum commission that can be set by the pool `root`. Once set, this value can
/// only be updated to a decreased value.
pub max: Option<Perbill>,
/// Optional configuration around how often commission can be updated, and when the last
/// commission update took place.
pub change_rate: Option<CommissionChangeRate<BlockNumberFor<T>>>,
/// The block from where throttling should be checked from. This value will be updated on all
/// commission updates and when setting an initial `change_rate`.
pub throttle_from: Option<BlockNumberFor<T>>,
}
impl<T: Config> Commission<T> {
/// Returns true if the current commission updating to `to` would exhaust the change rate
/// limits.
///
/// A commission update will be throttled (disallowed) if:
/// 1. not enough blocks have passed since the `throttle_from` block, if exists, or
/// 2. the new commission is greater than the maximum allowed increase.
fn throttling(&self, to: &Perbill) -> bool {
if let Some(t) = self.change_rate.as_ref() {
let commission_as_percent =
self.current.as_ref().map(|(x, _)| *x).unwrap_or(Perbill::zero());
// do not throttle if `to` is the same or a decrease in commission.
if *to <= commission_as_percent {
return false
}
// Test for `max_increase` throttling.
//
// Throttled if the attempted increase in commission is greater than `max_increase`.
if (*to).saturating_sub(commission_as_percent) > t.max_increase {
return true
}
// Test for `min_delay` throttling.
//
// Note: matching `None` is defensive only. `throttle_from` should always exist where
// `change_rate` has already been set, so this scenario should never happen.
return self.throttle_from.map_or_else(
|| {
defensive!("throttle_from should exist if change_rate is set");
true
},
|f| {
// if `min_delay` is zero (no delay), not throttling.
if t.min_delay == Zero::zero() {
false
} else {
// throttling if blocks passed is less than `min_delay`.
let blocks_surpassed =
<frame_system::Pallet<T>>::block_number().saturating_sub(f);
blocks_surpassed < t.min_delay
}
},
)
}
false
}
/// Gets the pool's current commission, or returns Perbill::zero if none is set.
/// Bounded to global max if current is greater than `GlobalMaxCommission`.
fn current(&self) -> Perbill {
self.current
.as_ref()
.map_or(Perbill::zero(), |(c, _)| *c)
.min(GlobalMaxCommission::<T>::get().unwrap_or(Bounded::max_value()))
}
/// Set the pool's commission.
///
/// Update commission based on `current`. If a `None` is supplied, allow the commission to be
/// removed without any change rate restrictions. Updates `throttle_from` to the current block.
/// If the supplied commission is zero, `None` will be inserted and `payee` will be ignored.
fn try_update_current(&mut self, current: &Option<(Perbill, T::AccountId)>) -> DispatchResult {
self.current = match current {
None => None,
Some((commission, payee)) => {
ensure!(!self.throttling(commission), Error::<T>::CommissionChangeThrottled);
ensure!(
commission <= &GlobalMaxCommission::<T>::get().unwrap_or(Bounded::max_value()),
Error::<T>::CommissionExceedsGlobalMaximum
);
ensure!(
self.max.map_or(true, |m| commission <= &m),
Error::<T>::CommissionExceedsMaximum
);
if commission.is_zero() {
None
} else {
Some((*commission, payee.clone()))
}
},
};
self.register_update();
Ok(())
}
/// Set the pool's maximum commission.
///
/// The pool's maximum commission can initially be set to any value, and only smaller values
/// thereafter. If larger values are attempted, this function will return a dispatch error.
///
/// If `current.0` is larger than the updated max commission value, `current.0` will also be
/// updated to the new maximum. This will also register a `throttle_from` update.
/// A `PoolCommissionUpdated` event is triggered if `current.0` is updated.
fn try_update_max(&mut self, pool_id: PoolId, new_max: Perbill) -> DispatchResult {
ensure!(
new_max <= GlobalMaxCommission::<T>::get().unwrap_or(Bounded::max_value()),
Error::<T>::CommissionExceedsGlobalMaximum
);
if let Some(old) = self.max.as_mut() {
if new_max > *old {
return Err(Error::<T>::MaxCommissionRestricted.into())
}
*old = new_max;
} else {
self.max = Some(new_max)
};
let updated_current = self
.current
.as_mut()
.map(|(c, _)| {
let u = *c > new_max;
*c = (*c).min(new_max);
u
})
.unwrap_or(false);
if updated_current {
if let Some((_, payee)) = self.current.as_ref() {
Pallet::<T>::deposit_event(Event::<T>::PoolCommissionUpdated {
pool_id,
current: Some((new_max, payee.clone())),
});
}
self.register_update();
}
Ok(())
}
/// Set the pool's commission `change_rate`.
///
/// Once a change rate configuration has been set, only more restrictive values can be set
/// thereafter. These restrictions translate to increased `min_delay` values and decreased
/// `max_increase` values.
///
/// Update `throttle_from` to the current block upon setting change rate for the first time, so
/// throttling can be checked from this block.
fn try_update_change_rate(
&mut self,
change_rate: CommissionChangeRate<BlockNumberFor<T>>,
) -> DispatchResult {
ensure!(!&self.less_restrictive(&change_rate), Error::<T>::CommissionChangeRateNotAllowed);
if self.change_rate.is_none() {
self.register_update();
}
self.change_rate = Some(change_rate);
Ok(())
}
/// Updates a commission's `throttle_from` field to the current block.
fn register_update(&mut self) {
self.throttle_from = Some(<frame_system::Pallet<T>>::block_number());
}
/// Checks whether a change rate is less restrictive than the current change rate, if any.
///
/// No change rate will always be less restrictive than some change rate, so where no
/// `change_rate` is currently set, `false` is returned.
fn less_restrictive(&self, new: &CommissionChangeRate<BlockNumberFor<T>>) -> bool {
self.change_rate
.as_ref()
.map(|c| new.max_increase > c.max_increase || new.min_delay < c.min_delay)
.unwrap_or(false)
}
}
/// Pool commission change rate preferences.
///
/// The pool root is able to set a commission change rate for their pool. A commission change rate
/// consists of 2 values; (1) the maximum allowed commission change, and (2) the minimum amount of
/// blocks that must elapse before commission updates are allowed again.
///
/// Commission change rates are not applied to decreases in commission.
#[derive(Encode, Decode, MaxEncodedLen, TypeInfo, Debug, PartialEq, Copy, Clone)]
pub struct CommissionChangeRate<BlockNumber> {
/// The maximum amount the commission can be updated by per `min_delay` period.
pub max_increase: Perbill,
/// How often an update can take place.
pub min_delay: BlockNumber,
}
/// Pool permissions and state
#[derive(Encode, Decode, MaxEncodedLen, TypeInfo, DebugNoBound, PartialEq, Clone)]
#[codec(mel_bound(T: Config))]
#[scale_info(skip_type_params(T))]
pub struct BondedPoolInner<T: Config> {
/// The commission rate of the pool.
pub commission: Commission<T>,
/// Count of members that belong to the pool.
pub member_counter: u32,
/// Total points of all the members in the pool who are actively bonded.
pub points: BalanceOf<T>,
/// See [`PoolRoles`].
pub roles: PoolRoles<T::AccountId>,
/// The current state of the pool.
pub state: PoolState,
}
/// A wrapper for bonded pools, with utility functions.
///
/// The main purpose of this is to wrap a [`BondedPoolInner`], with the account
/// + id of the pool, for easier access.
#[derive(RuntimeDebugNoBound)]
#[cfg_attr(feature = "std", derive(Clone, PartialEq))]
pub struct BondedPool<T: Config> {
/// The identifier of the pool.
id: PoolId,
/// The inner fields.
inner: BondedPoolInner<T>,
}
impl<T: Config> sp_std::ops::Deref for BondedPool<T> {
type Target = BondedPoolInner<T>;
fn deref(&self) -> &Self::Target {
&self.inner
}
}
impl<T: Config> sp_std::ops::DerefMut for BondedPool<T> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.inner
}
}
impl<T: Config> BondedPool<T> {
/// Create a new bonded pool with the given roles and identifier.
fn new(id: PoolId, roles: PoolRoles<T::AccountId>) -> Self {
Self {
id,
inner: BondedPoolInner {
commission: Commission::default(),
member_counter: Zero::zero(),
points: Zero::zero(),
roles,
state: PoolState::Open,
},
}
}
/// Get [`Self`] from storage. Returns `None` if no entry for `pool_account` exists.
pub fn get(id: PoolId) -> Option<Self> {
BondedPools::<T>::try_get(id).ok().map(|inner| Self { id, inner })
}
/// Get the bonded account id of this pool.
fn bonded_account(&self) -> T::AccountId {
Pallet::<T>::create_bonded_account(self.id)
}
/// Get the reward account id of this pool.
fn reward_account(&self) -> T::AccountId {
Pallet::<T>::create_reward_account(self.id)
}
/// Consume self and put into storage.
fn put(self) {
BondedPools::<T>::insert(self.id, self.inner);
}
/// Consume self and remove from storage.
fn remove(self) {
BondedPools::<T>::remove(self.id);
}
/// Convert the given amount of balance to points given the current pool state.
///
/// This is often used for bonding and issuing new funds into the pool.
fn balance_to_point(&self, new_funds: BalanceOf<T>) -> BalanceOf<T> {
let bonded_balance =
T::Staking::active_stake(&self.bonded_account()).unwrap_or(Zero::zero());
Pallet::<T>::balance_to_point(bonded_balance, self.points, new_funds)
}
/// Convert the given number of points to balance given the current pool state.
///
/// This is often used for unbonding.
fn points_to_balance(&self, points: BalanceOf<T>) -> BalanceOf<T> {
let bonded_balance =
T::Staking::active_stake(&self.bonded_account()).unwrap_or(Zero::zero());
Pallet::<T>::point_to_balance(bonded_balance, self.points, points)
}
/// Issue points to [`Self`] for `new_funds`.
fn issue(&mut self, new_funds: BalanceOf<T>) -> BalanceOf<T> {
let points_to_issue = self.balance_to_point(new_funds);
self.points = self.points.saturating_add(points_to_issue);
points_to_issue
}
/// Dissolve some points from the pool i.e. unbond the given amount of points from this pool.
/// This is the opposite of issuing some funds into the pool.
///
/// Mutates self in place, but does not write anything to storage.
///
/// Returns the equivalent balance amount that actually needs to get unbonded.
fn dissolve(&mut self, points: BalanceOf<T>) -> BalanceOf<T> {
// NOTE: do not optimize by removing `balance`. it must be computed before mutating
// `self.point`.
let balance = self.points_to_balance(points);
self.points = self.points.saturating_sub(points);
balance
}
/// Increment the member counter. Ensures that the pool and system member limits are
/// respected.
fn try_inc_members(&mut self) -> Result<(), DispatchError> {
ensure!(
MaxPoolMembersPerPool::<T>::get()
.map_or(true, |max_per_pool| self.member_counter < max_per_pool),
Error::<T>::MaxPoolMembers
);
ensure!(
MaxPoolMembers::<T>::get().map_or(true, |max| PoolMembers::<T>::count() < max),
Error::<T>::MaxPoolMembers
);
self.member_counter = self.member_counter.checked_add(1).ok_or(Error::<T>::OverflowRisk)?;
Ok(())
}
/// Decrement the member counter.
fn dec_members(mut self) -> Self {
self.member_counter = self.member_counter.defensive_saturating_sub(1);
self
}
/// The pools balance that is transferrable.
fn transferrable_balance(&self) -> BalanceOf<T> {
let account = self.bonded_account();
T::Currency::free_balance(&account)
.saturating_sub(T::Staking::active_stake(&account).unwrap_or_default())
}
fn is_root(&self, who: &T::AccountId) -> bool {
self.roles.root.as_ref().map_or(false, |root| root == who)
}
fn is_bouncer(&self, who: &T::AccountId) -> bool {
self.roles.bouncer.as_ref().map_or(false, |bouncer| bouncer == who)
}
fn can_update_roles(&self, who: &T::AccountId) -> bool {
self.is_root(who)
}
fn can_nominate(&self, who: &T::AccountId) -> bool {
self.is_root(who) ||
self.roles.nominator.as_ref().map_or(false, |nominator| nominator == who)
}
fn can_kick(&self, who: &T::AccountId) -> bool {
self.state == PoolState::Blocked && (self.is_root(who) || self.is_bouncer(who))
}
fn can_toggle_state(&self, who: &T::AccountId) -> bool {
(self.is_root(who) || self.is_bouncer(who)) && !self.is_destroying()
}
fn can_set_metadata(&self, who: &T::AccountId) -> bool {
self.is_root(who) || self.is_bouncer(who)
}
fn can_manage_commission(&self, who: &T::AccountId) -> bool {
self.is_root(who)
}
fn is_destroying(&self) -> bool {
matches!(self.state, PoolState::Destroying)
}
fn is_destroying_and_only_depositor(&self, alleged_depositor_points: BalanceOf<T>) -> bool {
// we need to ensure that `self.member_counter == 1` as well, because the depositor's
// initial `MinCreateBond` (or more) is what guarantees that the ledger of the pool does not
// get killed in the staking system, and that it does not fall below `MinimumNominatorBond`,
// which could prevent other non-depositor members from fully leaving. Thus, all members
// must withdraw, then depositor can unbond, and finally withdraw after waiting another
// cycle.
self.is_destroying() && self.points == alleged_depositor_points && self.member_counter == 1
}
/// Whether or not the pool is ok to be in `PoolSate::Open`. If this returns an `Err`, then the
/// pool is unrecoverable and should be in the destroying state.
fn ok_to_be_open(&self) -> Result<(), DispatchError> {
ensure!(!self.is_destroying(), Error::<T>::CanNotChangeState);
let bonded_balance =
T::Staking::active_stake(&self.bonded_account()).unwrap_or(Zero::zero());
ensure!(!bonded_balance.is_zero(), Error::<T>::OverflowRisk);
let points_to_balance_ratio_floor = self
.points
// We checked for zero above
.div(bonded_balance);
let max_points_to_balance = T::MaxPointsToBalance::get();
// Pool points can inflate relative to balance, but only if the pool is slashed.
// If we cap the ratio of points:balance so one cannot join a pool that has been slashed
// by `max_points_to_balance`%, if not zero.
ensure!(
points_to_balance_ratio_floor < max_points_to_balance.into(),
Error::<T>::OverflowRisk
);
// then we can be decently confident the bonding pool points will not overflow
// `BalanceOf<T>`. Note that these are just heuristics.
Ok(())
}
/// Check that the pool can accept a member with `new_funds`.
fn ok_to_join(&self) -> Result<(), DispatchError> {
ensure!(self.state == PoolState::Open, Error::<T>::NotOpen);
self.ok_to_be_open()?;
Ok(())
}
fn ok_to_unbond_with(
&self,
caller: &T::AccountId,
target_account: &T::AccountId,
target_member: &PoolMember<T>,
unbonding_points: BalanceOf<T>,
) -> Result<(), DispatchError> {
let is_permissioned = caller == target_account;
let is_depositor = *target_account == self.roles.depositor;
let is_full_unbond = unbonding_points == target_member.active_points();
let balance_after_unbond = {
let new_depositor_points =
target_member.active_points().saturating_sub(unbonding_points);
let mut target_member_after_unbond = (*target_member).clone();
target_member_after_unbond.points = new_depositor_points;
target_member_after_unbond.active_balance()
};
// any partial unbonding is only ever allowed if this unbond is permissioned.
ensure!(
is_permissioned || is_full_unbond,
Error::<T>::PartialUnbondNotAllowedPermissionlessly
);
// any unbond must comply with the balance condition:
ensure!(
is_full_unbond ||
balance_after_unbond >=
if is_depositor {
Pallet::<T>::depositor_min_bond()
} else {
MinJoinBond::<T>::get()
},
Error::<T>::MinimumBondNotMet
);
// additional checks:
match (is_permissioned, is_depositor) {
(true, false) => (),
(true, true) => {
// permission depositor unbond: if destroying and pool is empty, always allowed,
// with no additional limits.
if self.is_destroying_and_only_depositor(target_member.active_points()) {
// everything good, let them unbond anything.
} else {
// depositor cannot fully unbond yet.
ensure!(!is_full_unbond, Error::<T>::MinimumBondNotMet);
}
},
(false, false) => {
// If the pool is blocked, then an admin with kicking permissions can remove a
// member. If the pool is being destroyed, anyone can remove a member
debug_assert!(is_full_unbond);
ensure!(
self.can_kick(caller) || self.is_destroying(),
Error::<T>::NotKickerOrDestroying
)
},
(false, true) => {
// the depositor can simply not be unbonded permissionlessly, period.
return Err(Error::<T>::DoesNotHavePermission.into())
},
};
Ok(())
}
/// # Returns
///
/// * Ok(()) if [`Call::withdraw_unbonded`] can be called, `Err(DispatchError)` otherwise.
fn ok_to_withdraw_unbonded_with(
&self,
caller: &T::AccountId,
target_account: &T::AccountId,
) -> Result<(), DispatchError> {
// This isn't a depositor
let is_permissioned = caller == target_account;
ensure!(
is_permissioned || self.can_kick(caller) || self.is_destroying(),
Error::<T>::NotKickerOrDestroying
);
Ok(())
}
/// Bond exactly `amount` from `who`'s funds into this pool.
///
/// If the bond type is `Create`, `Staking::bond` is called, and `who`
/// is allowed to be killed. Otherwise, `Staking::bond_extra` is called and `who`
/// cannot be killed.
///
/// Returns `Ok(points_issues)`, `Err` otherwise.
fn try_bond_funds(
&mut self,
who: &T::AccountId,
amount: BalanceOf<T>,
ty: BondType,
) -> Result<BalanceOf<T>, DispatchError> {
// Cache the value
let bonded_account = self.bonded_account();
T::Currency::transfer(
who,
&bonded_account,
amount,
match ty {
BondType::Create => ExistenceRequirement::AllowDeath,
BondType::Later => ExistenceRequirement::KeepAlive,
},
)?;
// We must calculate the points issued *before* we bond who's funds, else points:balance
// ratio will be wrong.
let points_issued = self.issue(amount);
match ty {
BondType::Create => T::Staking::bond(&bonded_account, amount, &self.reward_account())?,
// The pool should always be created in such a way its in a state to bond extra, but if
// the active balance is slashed below the minimum bonded or the account cannot be
// found, we exit early.
BondType::Later => T::Staking::bond_extra(&bonded_account, amount)?,
}
Ok(points_issued)
}
// Set the state of `self`, and deposit an event if the state changed. State should never be set
// directly in in order to ensure a state change event is always correctly deposited.
fn set_state(&mut self, state: PoolState) {
if self.state != state {
self.state = state;
Pallet::<T>::deposit_event(Event::<T>::StateChanged {
pool_id: self.id,
new_state: state,
});
};
}
}
/// A reward pool.
///
/// A reward pool is not so much a pool anymore, since it does not contain any shares or points.
/// Rather, simply to fit nicely next to bonded pool and unbonding pools in terms of terminology. In
/// reality, a reward pool is just a container for a few pool-dependent data related to the rewards.
#[derive(Encode, Decode, MaxEncodedLen, TypeInfo, RuntimeDebugNoBound)]
#[cfg_attr(feature = "std", derive(Clone, PartialEq, DefaultNoBound))]
#[codec(mel_bound(T: Config))]
#[scale_info(skip_type_params(T))]
pub struct RewardPool<T: Config> {
/// The last recorded value of the reward counter.
///
/// This is updated ONLY when the points in the bonded pool change, which means `join`,
/// `bond_extra` and `unbond`, all of which is done through `update_recorded`.
last_recorded_reward_counter: T::RewardCounter,
/// The last recorded total payouts of the reward pool.
///
/// Payouts is essentially income of the pool.
///
/// Update criteria is same as that of `last_recorded_reward_counter`.
last_recorded_total_payouts: BalanceOf<T>,
/// Total amount that this pool has paid out so far to the members.
total_rewards_claimed: BalanceOf<T>,
/// The amount of commission pending to be claimed.
total_commission_pending: BalanceOf<T>,
/// The amount of commission that has been claimed.
total_commission_claimed: BalanceOf<T>,
}
impl<T: Config> RewardPool<T> {
/// Getter for [`RewardPool::last_recorded_reward_counter`].
pub(crate) fn last_recorded_reward_counter(&self) -> T::RewardCounter {
self.last_recorded_reward_counter
}
/// Register some rewards that are claimed from the pool by the members.
fn register_claimed_reward(&mut self, reward: BalanceOf<T>) {
self.total_rewards_claimed = self.total_rewards_claimed.saturating_add(reward);
}
/// Update the recorded values of the reward pool.
///
/// This function MUST be called whenever the points in the bonded pool change, AND whenever the
/// the pools commission is updated. The reason for the former is that a change in pool points
/// will alter the share of the reward balance among pool members, and the reason for the latter
/// is that a change in commission will alter the share of the reward balance among the pool.
fn update_records(
&mut self,
id: PoolId,
bonded_points: BalanceOf<T>,
commission: Perbill,
) -> Result<(), Error<T>> {
let balance = Self::current_balance(id);
let (current_reward_counter, new_pending_commission) =
self.current_reward_counter(id, bonded_points, commission)?;
// Store the reward counter at the time of this update. This is used in subsequent calls to
// `current_reward_counter`, whereby newly pending rewards (in points) are added to this
// value.
self.last_recorded_reward_counter = current_reward_counter;
// Add any new pending commission that has been calculated from `current_reward_counter` to
// determine the total pending commission at the time of this update.
self.total_commission_pending =
self.total_commission_pending.saturating_add(new_pending_commission);
// Store the total payouts at the time of this update. Total payouts are essentially the
// entire historical balance of the reward pool, equating to the current balance + the total
// rewards that have left the pool + the total commission that has left the pool.
self.last_recorded_total_payouts = balance
.checked_add(&self.total_rewards_claimed.saturating_add(self.total_commission_claimed))
.ok_or(Error::<T>::OverflowRisk)?;
Ok(())
}
/// Get the current reward counter, based on the given `bonded_points` being the state of the
/// bonded pool at this time.
fn current_reward_counter(
&self,
id: PoolId,
bonded_points: BalanceOf<T>,
commission: Perbill,
) -> Result<(T::RewardCounter, BalanceOf<T>), Error<T>> {
let balance = Self::current_balance(id);
// Calculate the current payout balance. The first 3 values of this calculation added
// together represent what the balance would be if no payouts were made. The
// `last_recorded_total_payouts` is then subtracted from this value to cancel out previously
// recorded payouts, leaving only the remaining payouts that have not been claimed.
let current_payout_balance = balance
.saturating_add(self.total_rewards_claimed)
.saturating_add(self.total_commission_claimed)
.saturating_sub(self.last_recorded_total_payouts);
// Split the `current_payout_balance` into claimable rewards and claimable commission
// according to the current commission rate.
let new_pending_commission = commission * current_payout_balance;
let new_pending_rewards = current_payout_balance.saturating_sub(new_pending_commission);
// * accuracy notes regarding the multiplication in `checked_from_rational`:
// `current_payout_balance` is a subset of the total_issuance at the very worse.
// `bonded_points` are similarly, in a non-slashed pool, have the same granularity as
// balance, and are thus below within the range of total_issuance. In the worse case
// scenario, for `saturating_from_rational`, we have:
//
// dot_total_issuance * 10^18 / `minJoinBond`
//
// assuming `MinJoinBond == ED`
//
// dot_total_issuance * 10^18 / 10^10 = dot_total_issuance * 10^8
//
// which, with the current numbers, is a miniscule fraction of the u128 capacity.
//
// Thus, adding two values of type reward counter should be safe for ages in a chain like
// Polkadot. The important note here is that `reward_pool.last_recorded_reward_counter` only
// ever accumulates, but its semantics imply that it is less than total_issuance, when
// represented as `FixedU128`, which means it is less than `total_issuance * 10^18`.
//
// * accuracy notes regarding `checked_from_rational` collapsing to zero, meaning that no
// reward can be claimed:
//
// largest `bonded_points`, such that the reward counter is non-zero, with `FixedU128` will
// be when the payout is being computed. This essentially means `payout/bonded_points` needs
// to be more than 1/1^18. Thus, assuming that `bonded_points` will always be less than `10
// * dot_total_issuance`, if the reward_counter is the smallest possible value, the value of
// the
// reward being calculated is:
//
// x / 10^20 = 1/ 10^18
//
// x = 100
//
// which is basically 10^-8 DOTs. See `smallest_claimable_reward` for an example of this.
let current_reward_counter =
T::RewardCounter::checked_from_rational(new_pending_rewards, bonded_points)
.and_then(|ref r| self.last_recorded_reward_counter.checked_add(r))
.ok_or(Error::<T>::OverflowRisk)?;
Ok((current_reward_counter, new_pending_commission))
}
/// Current free balance of the reward pool.
///
/// This is sum of all the rewards that are claimable by pool members.
fn current_balance(id: PoolId) -> BalanceOf<T> {
T::Currency::free_balance(&Pallet::<T>::create_reward_account(id))
.saturating_sub(T::Currency::minimum_balance())
}
}
/// An unbonding pool. This is always mapped with an era.
#[derive(Encode, Decode, MaxEncodedLen, TypeInfo, DefaultNoBound, RuntimeDebugNoBound)]
#[cfg_attr(feature = "std", derive(Clone, PartialEq, Eq))]
#[codec(mel_bound(T: Config))]
#[scale_info(skip_type_params(T))]
pub struct UnbondPool<T: Config> {
/// The points in this pool.
points: BalanceOf<T>,
/// The funds in the pool.
balance: BalanceOf<T>,
}
impl<T: Config> UnbondPool<T> {
fn balance_to_point(&self, new_funds: BalanceOf<T>) -> BalanceOf<T> {
Pallet::<T>::balance_to_point(self.balance, self.points, new_funds)
}
fn point_to_balance(&self, points: BalanceOf<T>) -> BalanceOf<T> {
Pallet::<T>::point_to_balance(self.balance, self.points, points)
}
/// Issue the equivalent points of `new_funds` into self.
///
/// Returns the actual amounts of points issued.
fn issue(&mut self, new_funds: BalanceOf<T>) -> BalanceOf<T> {
let new_points = self.balance_to_point(new_funds);
self.points = self.points.saturating_add(new_points);
self.balance = self.balance.saturating_add(new_funds);
new_points
}
/// Dissolve some points from the unbonding pool, reducing the balance of the pool
/// proportionally.
///
/// This is the opposite of `issue`.
///
/// Returns the actual amount of `Balance` that was removed from the pool.
fn dissolve(&mut self, points: BalanceOf<T>) -> BalanceOf<T> {
let balance_to_unbond = self.point_to_balance(points);
self.points = self.points.saturating_sub(points);
self.balance = self.balance.saturating_sub(balance_to_unbond);
balance_to_unbond
}
}
#[derive(Encode, Decode, MaxEncodedLen, TypeInfo, DefaultNoBound, RuntimeDebugNoBound)]
#[cfg_attr(feature = "std", derive(Clone, PartialEq))]
#[codec(mel_bound(T: Config))]
#[scale_info(skip_type_params(T))]
pub struct SubPools<T: Config> {
/// A general, era agnostic pool of funds that have fully unbonded. The pools
/// of `Self::with_era` will lazily be merged into into this pool if they are
/// older then `current_era - TotalUnbondingPools`.
no_era: UnbondPool<T>,
/// Map of era in which a pool becomes unbonded in => unbond pools.
with_era: BoundedBTreeMap<EraIndex, UnbondPool<T>, TotalUnbondingPools<T>>,
}
impl<T: Config> SubPools<T> {
/// Merge the oldest `with_era` unbond pools into the `no_era` unbond pool.
///
/// This is often used whilst getting the sub-pool from storage, thus it consumes and returns
/// `Self` for ergonomic purposes.
fn maybe_merge_pools(mut self, current_era: EraIndex) -> Self {
// Ex: if `TotalUnbondingPools` is 5 and current era is 10, we only want to retain pools
// 6..=10. Note that in the first few eras where `checked_sub` is `None`, we don't remove
// anything.
if let Some(newest_era_to_remove) =
current_era.checked_sub(T::PostUnbondingPoolsWindow::get())
{
self.with_era.retain(|k, v| {
if *k > newest_era_to_remove {
// keep
true
} else {
// merge into the no-era pool
self.no_era.points = self.no_era.points.saturating_add(v.points);
self.no_era.balance = self.no_era.balance.saturating_add(v.balance);
false
}
});
}
self
}
/// The sum of all unbonding balance, regardless of whether they are actually unlocked or not.
#[cfg(any(feature = "try-runtime", feature = "fuzzing", test, debug_assertions))]
fn sum_unbonding_balance(&self) -> BalanceOf<T> {
self.no_era.balance.saturating_add(
self.with_era
.values()
.fold(BalanceOf::<T>::zero(), |acc, pool| acc.saturating_add(pool.balance)),
)
}
}
/// The maximum amount of eras an unbonding pool can exist prior to being merged with the
/// `no_era` pool. This is guaranteed to at least be equal to the staking `UnbondingDuration`. For
/// improved UX [`Config::PostUnbondingPoolsWindow`] should be configured to a non-zero value.
pub struct TotalUnbondingPools<T: Config>(PhantomData<T>);
impl<T: Config> Get<u32> for TotalUnbondingPools<T> {
fn get() -> u32 {
// NOTE: this may be dangerous in the scenario bonding_duration gets decreased because
// we would no longer be able to decode `BoundedBTreeMap::<EraIndex, UnbondPool<T>,
// TotalUnbondingPools<T>>`, which uses `TotalUnbondingPools` as the bound
T::Staking::bonding_duration() + T::PostUnbondingPoolsWindow::get()
}
}
#[frame_support::pallet]
pub mod pallet {
use super::*;
use frame_support::traits::StorageVersion;
use frame_system::{ensure_signed, pallet_prelude::*};
use sp_runtime::Perbill;
/// The current storage version.
const STORAGE_VERSION: StorageVersion = StorageVersion::new(5);
#[pallet::pallet]
#[pallet::storage_version(STORAGE_VERSION)]
pub struct Pallet<T>(_);
#[pallet::config]
pub trait Config: frame_system::Config {
/// The overarching event type.
type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
/// Weight information for extrinsics in this pallet.
type WeightInfo: weights::WeightInfo;
/// The nominating balance.
type Currency: Currency<Self::AccountId>;
/// The type that is used for reward counter.
///
/// The arithmetic of the reward counter might saturate based on the size of the
/// `Currency::Balance`. If this happens, operations fails. Nonetheless, this type should be
/// chosen such that this failure almost never happens, as if it happens, the pool basically
/// needs to be dismantled (or all pools migrated to a larger `RewardCounter` type, which is
/// a PITA to do).
///
/// See the inline code docs of `Member::pending_rewards` and `RewardPool::update_recorded`
/// for example analysis. A [`sp_runtime::FixedU128`] should be fine for chains with balance
/// types similar to that of Polkadot and Kusama, in the absence of severe slashing (or
/// prevented via a reasonable `MaxPointsToBalance`), for many many years to come.
type RewardCounter: FixedPointNumber + MaxEncodedLen + TypeInfo + Default + codec::FullCodec;
/// The nomination pool's pallet id.
#[pallet::constant]
type PalletId: Get<frame_support::PalletId>;
/// The maximum pool points-to-balance ratio that an `open` pool can have.
///
/// This is important in the event slashing takes place and the pool's points-to-balance
/// ratio becomes disproportional.
///
/// Moreover, this relates to the `RewardCounter` type as well, as the arithmetic operations
/// are a function of number of points, and by setting this value to e.g. 10, you ensure
/// that the total number of points in the system are at most 10 times the total_issuance of
/// the chain, in the absolute worse case.
///
/// For a value of 10, the threshold would be a pool points-to-balance ratio of 10:1.
/// Such a scenario would also be the equivalent of the pool being 90% slashed.
#[pallet::constant]
type MaxPointsToBalance: Get<u8>;
/// Infallible method for converting `Currency::Balance` to `U256`.
type BalanceToU256: Convert<BalanceOf<Self>, U256>;
/// Infallible method for converting `U256` to `Currency::Balance`.
type U256ToBalance: Convert<U256, BalanceOf<Self>>;
/// The interface for nominating.
type Staking: StakingInterface<Balance = BalanceOf<Self>, AccountId = Self::AccountId>;
/// The amount of eras a `SubPools::with_era` pool can exist before it gets merged into the
/// `SubPools::no_era` pool. In other words, this is the amount of eras a member will be
/// able to withdraw from an unbonding pool which is guaranteed to have the correct ratio of
/// points to balance; once the `with_era` pool is merged into the `no_era` pool, the ratio
/// can become skewed due to some slashed ratio getting merged in at some point.
type PostUnbondingPoolsWindow: Get<u32>;
/// The maximum length, in bytes, that a pools metadata maybe.
type MaxMetadataLen: Get<u32>;
/// The maximum number of simultaneous unbonding chunks that can exist per member.
type MaxUnbonding: Get<u32>;
}
/// Minimum amount to bond to join a pool.
#[pallet::storage]
pub type MinJoinBond<T: Config> = StorageValue<_, BalanceOf<T>, ValueQuery>;
/// Minimum bond required to create a pool.
///
/// This is the amount that the depositor must put as their initial stake in the pool, as an
/// indication of "skin in the game".
///
/// This is the value that will always exist in the staking ledger of the pool bonded account
/// while all other accounts leave.
#[pallet::storage]
pub type MinCreateBond<T: Config> = StorageValue<_, BalanceOf<T>, ValueQuery>;
/// Maximum number of nomination pools that can exist. If `None`, then an unbounded number of
/// pools can exist.
#[pallet::storage]
pub type MaxPools<T: Config> = StorageValue<_, u32, OptionQuery>;
/// Maximum number of members that can exist in the system. If `None`, then the count
/// members are not bound on a system wide basis.
#[pallet::storage]
pub type MaxPoolMembers<T: Config> = StorageValue<_, u32, OptionQuery>;
/// Maximum number of members that may belong to pool. If `None`, then the count of
/// members is not bound on a per pool basis.
#[pallet::storage]
pub type MaxPoolMembersPerPool<T: Config> = StorageValue<_, u32, OptionQuery>;
/// The maximum commission that can be charged by a pool. Used on commission payouts to bound
/// pool commissions that are > `GlobalMaxCommission`, necessary if a future
/// `GlobalMaxCommission` is lower than some current pool commissions.
#[pallet::storage]
pub type GlobalMaxCommission<T: Config> = StorageValue<_, Perbill, OptionQuery>;
/// Active members.
///
/// TWOX-NOTE: SAFE since `AccountId` is a secure hash.
#[pallet::storage]
pub type PoolMembers<T: Config> =
CountedStorageMap<_, Twox64Concat, T::AccountId, PoolMember<T>>;
/// Storage for bonded pools.
// To get or insert a pool see [`BondedPool::get`] and [`BondedPool::put`]
#[pallet::storage]
pub type BondedPools<T: Config> =
CountedStorageMap<_, Twox64Concat, PoolId, BondedPoolInner<T>>;
/// Reward pools. This is where there rewards for each pool accumulate. When a members payout is
/// claimed, the balance comes out fo the reward pool. Keyed by the bonded pools account.
#[pallet::storage]
pub type RewardPools<T: Config> = CountedStorageMap<_, Twox64Concat, PoolId, RewardPool<T>>;
/// Groups of unbonding pools. Each group of unbonding pools belongs to a
/// bonded pool, hence the name sub-pools. Keyed by the bonded pools account.
#[pallet::storage]
pub type SubPoolsStorage<T: Config> = CountedStorageMap<_, Twox64Concat, PoolId, SubPools<T>>;
/// Metadata for the pool.
#[pallet::storage]
pub type Metadata<T: Config> =
CountedStorageMap<_, Twox64Concat, PoolId, BoundedVec<u8, T::MaxMetadataLen>, ValueQuery>;
/// Ever increasing number of all pools created so far.
#[pallet::storage]
pub type LastPoolId<T: Config> = StorageValue<_, u32, ValueQuery>;
/// A reverse lookup from the pool's account id to its id.
///
/// This is only used for slashing. In all other instances, the pool id is used, and the
/// accounts are deterministically derived from it.
#[pallet::storage]
pub type ReversePoolIdLookup<T: Config> =
CountedStorageMap<_, Twox64Concat, T::AccountId, PoolId, OptionQuery>;
/// Map from a pool member account to their opted claim permission.
#[pallet::storage]
pub type ClaimPermissions<T: Config> =
StorageMap<_, Twox64Concat, T::AccountId, ClaimPermission, ValueQuery>;
#[pallet::genesis_config]
pub struct GenesisConfig<T: Config> {
pub min_join_bond: BalanceOf<T>,
pub min_create_bond: BalanceOf<T>,
pub max_pools: Option<u32>,
pub max_members_per_pool: Option<u32>,
pub max_members: Option<u32>,
pub global_max_commission: Option<Perbill>,
}
impl<T: Config> Default for GenesisConfig<T> {
fn default() -> Self {
Self {
min_join_bond: Zero::zero(),
min_create_bond: Zero::zero(),
max_pools: Some(16),
max_members_per_pool: Some(32),
max_members: Some(16 * 32),
global_max_commission: None,
}
}
}
#[pallet::genesis_build]
impl<T: Config> BuildGenesisConfig for GenesisConfig<T> {
fn build(&self) {
MinJoinBond::<T>::put(self.min_join_bond);
MinCreateBond::<T>::put(self.min_create_bond);
if let Some(max_pools) = self.max_pools {
MaxPools::<T>::put(max_pools);
}
if let Some(max_members_per_pool) = self.max_members_per_pool {
MaxPoolMembersPerPool::<T>::put(max_members_per_pool);
}
if let Some(max_members) = self.max_members {
MaxPoolMembers::<T>::put(max_members);
}
if let Some(global_max_commission) = self.global_max_commission {
GlobalMaxCommission::<T>::put(global_max_commission);
}
}
}
/// Events of this pallet.
#[pallet::event]
#[pallet::generate_deposit(pub(crate) fn deposit_event)]
pub enum Event<T: Config> {
/// A pool has been created.
Created { depositor: T::AccountId, pool_id: PoolId },
/// A member has became bonded in a pool.
Bonded { member: T::AccountId, pool_id: PoolId, bonded: BalanceOf<T>, joined: bool },
/// A payout has been made to a member.
PaidOut { member: T::AccountId, pool_id: PoolId, payout: BalanceOf<T> },
/// A member has unbonded from their pool.
///
/// - `balance` is the corresponding balance of the number of points that has been
/// requested to be unbonded (the argument of the `unbond` transaction) from the bonded
/// pool.
/// - `points` is the number of points that are issued as a result of `balance` being
/// dissolved into the corresponding unbonding pool.
/// - `era` is the era in which the balance will be unbonded.
/// In the absence of slashing, these values will match. In the presence of slashing, the
/// number of points that are issued in the unbonding pool will be less than the amount
/// requested to be unbonded.
Unbonded {
member: T::AccountId,
pool_id: PoolId,
balance: BalanceOf<T>,
points: BalanceOf<T>,
era: EraIndex,
},
/// A member has withdrawn from their pool.
///
/// The given number of `points` have been dissolved in return of `balance`.
///
/// Similar to `Unbonded` event, in the absence of slashing, the ratio of point to balance
/// will be 1.
Withdrawn {
member: T::AccountId,
pool_id: PoolId,
balance: BalanceOf<T>,
points: BalanceOf<T>,
},
/// A pool has been destroyed.
Destroyed { pool_id: PoolId },
/// The state of a pool has changed
StateChanged { pool_id: PoolId, new_state: PoolState },
/// A member has been removed from a pool.
///
/// The removal can be voluntary (withdrawn all unbonded funds) or involuntary (kicked).
MemberRemoved { pool_id: PoolId, member: T::AccountId },
/// The roles of a pool have been updated to the given new roles. Note that the depositor
/// can never change.
RolesUpdated {
root: Option<T::AccountId>,
bouncer: Option<T::AccountId>,
nominator: Option<T::AccountId>,
},
/// The active balance of pool `pool_id` has been slashed to `balance`.
PoolSlashed { pool_id: PoolId, balance: BalanceOf<T> },
/// The unbond pool at `era` of pool `pool_id` has been slashed to `balance`.
UnbondingPoolSlashed { pool_id: PoolId, era: EraIndex, balance: BalanceOf<T> },
/// A pool's commission setting has been changed.
PoolCommissionUpdated { pool_id: PoolId, current: Option<(Perbill, T::AccountId)> },
/// A pool's maximum commission setting has been changed.
PoolMaxCommissionUpdated { pool_id: PoolId, max_commission: Perbill },
/// A pool's commission `change_rate` has been changed.
PoolCommissionChangeRateUpdated {
pool_id: PoolId,
change_rate: CommissionChangeRate<BlockNumberFor<T>>,
},
/// Pool commission has been claimed.
PoolCommissionClaimed { pool_id: PoolId, commission: BalanceOf<T> },
}
#[pallet::error]
#[cfg_attr(test, derive(PartialEq))]
pub enum Error<T> {
/// A (bonded) pool id does not exist.
PoolNotFound,
/// An account is not a member.
PoolMemberNotFound,
/// A reward pool does not exist. In all cases this is a system logic error.
RewardPoolNotFound,
/// A sub pool does not exist.
SubPoolsNotFound,
/// An account is already delegating in another pool. An account may only belong to one
/// pool at a time.
AccountBelongsToOtherPool,
/// The member is fully unbonded (and thus cannot access the bonded and reward pool
/// anymore to, for example, collect rewards).
FullyUnbonding,
/// The member cannot unbond further chunks due to reaching the limit.
MaxUnbondingLimit,
/// None of the funds can be withdrawn yet because the bonding duration has not passed.
CannotWithdrawAny,
/// The amount does not meet the minimum bond to either join or create a pool.
///
/// The depositor can never unbond to a value less than
/// `Pallet::depositor_min_bond`. The caller does not have nominating
/// permissions for the pool. Members can never unbond to a value below `MinJoinBond`.
MinimumBondNotMet,
/// The transaction could not be executed due to overflow risk for the pool.
OverflowRisk,
/// A pool must be in [`PoolState::Destroying`] in order for the depositor to unbond or for
/// other members to be permissionlessly unbonded.
NotDestroying,
/// The caller does not have nominating permissions for the pool.
NotNominator,
/// Either a) the caller cannot make a valid kick or b) the pool is not destroying.
NotKickerOrDestroying,
/// The pool is not open to join
NotOpen,
/// The system is maxed out on pools.
MaxPools,
/// Too many members in the pool or system.
MaxPoolMembers,
/// The pools state cannot be changed.
CanNotChangeState,
/// The caller does not have adequate permissions.
DoesNotHavePermission,
/// Metadata exceeds [`Config::MaxMetadataLen`]
MetadataExceedsMaxLen,
/// Some error occurred that should never happen. This should be reported to the
/// maintainers.
Defensive(DefensiveError),
/// Partial unbonding now allowed permissionlessly.
PartialUnbondNotAllowedPermissionlessly,
/// The pool's max commission cannot be set higher than the existing value.
MaxCommissionRestricted,
/// The supplied commission exceeds the max allowed commission.
CommissionExceedsMaximum,
/// The supplied commission exceeds global maximum commission.
CommissionExceedsGlobalMaximum,
/// Not enough blocks have surpassed since the last commission update.
CommissionChangeThrottled,
/// The submitted changes to commission change rate are not allowed.
CommissionChangeRateNotAllowed,
/// There is no pending commission to claim.
NoPendingCommission,
/// No commission current has been set.
NoCommissionCurrentSet,
/// Pool id currently in use.
PoolIdInUse,
/// Pool id provided is not correct/usable.
InvalidPoolId,
/// Bonding extra is restricted to the exact pending reward amount.
BondExtraRestricted,
}
#[derive(Encode, Decode, PartialEq, TypeInfo, PalletError, RuntimeDebug)]
pub enum DefensiveError {
/// There isn't enough space in the unbond pool.
NotEnoughSpaceInUnbondPool,
/// A (bonded) pool id does not exist.
PoolNotFound,
/// A reward pool does not exist. In all cases this is a system logic error.
RewardPoolNotFound,
/// A sub pool does not exist.
SubPoolsNotFound,
/// The bonded account should only be killed by the staking system when the depositor is
/// withdrawing
BondedStashKilledPrematurely,
}
impl<T> From<DefensiveError> for Error<T> {
fn from(e: DefensiveError) -> Error<T> {
Error::<T>::Defensive(e)
}
}
#[pallet::call]
impl<T: Config> Pallet<T> {
/// Stake funds with a pool. The amount to bond is transferred from the member to the
/// pools account and immediately increases the pools bond.
///
/// # Note
///
/// * An account can only be a member of a single pool.
/// * An account cannot join the same pool multiple times.
/// * This call will *not* dust the member account, so the member must have at least
/// `existential deposit + amount` in their account.
/// * Only a pool with [`PoolState::Open`] can be joined
#[pallet::call_index(0)]
#[pallet::weight(T::WeightInfo::join())]
pub fn join(
origin: OriginFor<T>,
#[pallet::compact] amount: BalanceOf<T>,
pool_id: PoolId,
) -> DispatchResult {
let who = ensure_signed(origin)?;
ensure!(amount >= MinJoinBond::<T>::get(), Error::<T>::MinimumBondNotMet);
// If a member already exists that means they already belong to a pool
ensure!(!PoolMembers::<T>::contains_key(&who), Error::<T>::AccountBelongsToOtherPool);
let mut bonded_pool = BondedPool::<T>::get(pool_id).ok_or(Error::<T>::PoolNotFound)?;
bonded_pool.ok_to_join()?;
let mut reward_pool = RewardPools::<T>::get(pool_id)
.defensive_ok_or::<Error<T>>(DefensiveError::RewardPoolNotFound.into())?;
// IMPORTANT: reward pool records must be updated with the old points.
reward_pool.update_records(
pool_id,
bonded_pool.points,
bonded_pool.commission.current(),
)?;
bonded_pool.try_inc_members()?;
let points_issued = bonded_pool.try_bond_funds(&who, amount, BondType::Later)?;
PoolMembers::insert(
who.clone(),
PoolMember::<T> {
pool_id,
points: points_issued,
// we just updated `last_known_reward_counter` to the current one in
// `update_recorded`.
last_recorded_reward_counter: reward_pool.last_recorded_reward_counter(),
unbonding_eras: Default::default(),
},
);
Self::deposit_event(Event::<T>::Bonded {
member: who,
pool_id,
bonded: amount,
joined: true,
});
bonded_pool.put();
RewardPools::<T>::insert(pool_id, reward_pool);
Ok(())
}
/// Bond `extra` more funds from `origin` into the pool to which they already belong.
///
/// Additional funds can come from either the free balance of the account, of from the
/// accumulated rewards, see [`BondExtra`].
///
/// Bonding extra funds implies an automatic payout of all pending rewards as well.
/// See `bond_extra_other` to bond pending rewards of `other` members.
// NOTE: this transaction is implemented with the sole purpose of readability and
// correctness, not optimization. We read/write several storage items multiple times instead
// of just once, in the spirit reusing code.
#[pallet::call_index(1)]
#[pallet::weight(
T::WeightInfo::bond_extra_transfer()
.max(T::WeightInfo::bond_extra_other())
)]
pub fn bond_extra(origin: OriginFor<T>, extra: BondExtra<BalanceOf<T>>) -> DispatchResult {
let who = ensure_signed(origin)?;
Self::do_bond_extra(who.clone(), who, extra)
}
/// A bonded member can use this to claim their payout based on the rewards that the pool
/// has accumulated since their last claimed payout (OR since joining if this is their first
/// time claiming rewards). The payout will be transferred to the member's account.
///
/// The member will earn rewards pro rata based on the members stake vs the sum of the
/// members in the pools stake. Rewards do not "expire".
///
/// See `claim_payout_other` to caim rewards on bahalf of some `other` pool member.
#[pallet::call_index(2)]
#[pallet::weight(T::WeightInfo::claim_payout())]
pub fn claim_payout(origin: OriginFor<T>) -> DispatchResult {
let signer = ensure_signed(origin)?;
Self::do_claim_payout(signer.clone(), signer)
}
/// Unbond up to `unbonding_points` of the `member_account`'s funds from the pool. It
/// implicitly collects the rewards one last time, since not doing so would mean some
/// rewards would be forfeited.
///
/// Under certain conditions, this call can be dispatched permissionlessly (i.e. by any
/// account).
///
/// # Conditions for a permissionless dispatch.
///
/// * The pool is blocked and the caller is either the root or bouncer. This is refereed to
/// as a kick.
/// * The pool is destroying and the member is not the depositor.
/// * The pool is destroying, the member is the depositor and no other members are in the
/// pool.
///
/// ## Conditions for permissioned dispatch (i.e. the caller is also the
/// `member_account`):
///
/// * The caller is not the depositor.
/// * The caller is the depositor, the pool is destroying and no other members are in the
/// pool.
///
/// # Note
///
/// If there are too many unlocking chunks to unbond with the pool account,
/// [`Call::pool_withdraw_unbonded`] can be called to try and minimize unlocking chunks.
/// The [`StakingInterface::unbond`] will implicitly call [`Call::pool_withdraw_unbonded`]
/// to try to free chunks if necessary (ie. if unbound was called and no unlocking chunks
/// are available). However, it may not be possible to release the current unlocking chunks,
/// in which case, the result of this call will likely be the `NoMoreChunks` error from the
/// staking system.
#[pallet::call_index(3)]
#[pallet::weight(T::WeightInfo::unbond())]
pub fn unbond(
origin: OriginFor<T>,
member_account: AccountIdLookupOf<T>,
#[pallet::compact] unbonding_points: BalanceOf<T>,
) -> DispatchResult {
let who = ensure_signed(origin)?;
let member_account = T::Lookup::lookup(member_account)?;
let (mut member, mut bonded_pool, mut reward_pool) =
Self::get_member_with_pools(&member_account)?;
bonded_pool.ok_to_unbond_with(&who, &member_account, &member, unbonding_points)?;
// Claim the the payout prior to unbonding. Once the user is unbonding their points no
// longer exist in the bonded pool and thus they can no longer claim their payouts. It
// is not strictly necessary to claim the rewards, but we do it here for UX.
reward_pool.update_records(
bonded_pool.id,
bonded_pool.points,
bonded_pool.commission.current(),
)?;
let _ = Self::do_reward_payout(&who, &mut member, &mut bonded_pool, &mut reward_pool)?;
let current_era = T::Staking::current_era();
let unbond_era = T::Staking::bonding_duration().saturating_add(current_era);
// Unbond in the actual underlying nominator.
let unbonding_balance = bonded_pool.dissolve(unbonding_points);
T::Staking::unbond(&bonded_pool.bonded_account(), unbonding_balance)?;
// Note that we lazily create the unbonding pools here if they don't already exist
let mut sub_pools = SubPoolsStorage::<T>::get(member.pool_id)
.unwrap_or_default()
.maybe_merge_pools(current_era);
// Update the unbond pool associated with the current era with the unbonded funds. Note
// that we lazily create the unbond pool if it does not yet exist.
if !sub_pools.with_era.contains_key(&unbond_era) {
sub_pools
.with_era
.try_insert(unbond_era, UnbondPool::default())
// The above call to `maybe_merge_pools` should ensure there is
// always enough space to insert.
.defensive_map_err::<Error<T>, _>(|_| {
DefensiveError::NotEnoughSpaceInUnbondPool.into()
})?;
}
let points_unbonded = sub_pools
.with_era
.get_mut(&unbond_era)
// The above check ensures the pool exists.
.defensive_ok_or::<Error<T>>(DefensiveError::PoolNotFound.into())?
.issue(unbonding_balance);
// Try and unbond in the member map.
member.try_unbond(unbonding_points, points_unbonded, unbond_era)?;
Self::deposit_event(Event::<T>::Unbonded {
member: member_account.clone(),
pool_id: member.pool_id,
points: points_unbonded,
balance: unbonding_balance,
era: unbond_era,
});
// Now that we know everything has worked write the items to storage.
SubPoolsStorage::insert(member.pool_id, sub_pools);
Self::put_member_with_pools(&member_account, member, bonded_pool, reward_pool);
Ok(())
}
/// Call `withdraw_unbonded` for the pools account. This call can be made by any account.
///
/// This is useful if their are too many unlocking chunks to call `unbond`, and some
/// can be cleared by withdrawing. In the case there are too many unlocking chunks, the user
/// would probably see an error like `NoMoreChunks` emitted from the staking system when
/// they attempt to unbond.
#[pallet::call_index(4)]
#[pallet::weight(T::WeightInfo::pool_withdraw_unbonded(*num_slashing_spans))]
pub fn pool_withdraw_unbonded(
origin: OriginFor<T>,
pool_id: PoolId,
num_slashing_spans: u32,
) -> DispatchResult {
let _ = ensure_signed(origin)?;
let pool = BondedPool::<T>::get(pool_id).ok_or(Error::<T>::PoolNotFound)?;
// For now we only allow a pool to withdraw unbonded if its not destroying. If the pool
// is destroying then `withdraw_unbonded` can be used.
ensure!(pool.state != PoolState::Destroying, Error::<T>::NotDestroying);
T::Staking::withdraw_unbonded(pool.bonded_account(), num_slashing_spans)?;
Ok(())
}
/// Withdraw unbonded funds from `member_account`. If no bonded funds can be unbonded, an
/// error is returned.
///
/// Under certain conditions, this call can be dispatched permissionlessly (i.e. by any
/// account).
///
/// # Conditions for a permissionless dispatch
///
/// * The pool is in destroy mode and the target is not the depositor.
/// * The target is the depositor and they are the only member in the sub pools.
/// * The pool is blocked and the caller is either the root or bouncer.
///
/// # Conditions for permissioned dispatch
///
/// * The caller is the target and they are not the depositor.
///
/// # Note
///
/// If the target is the depositor, the pool will be destroyed.
#[pallet::call_index(5)]
#[pallet::weight(
T::WeightInfo::withdraw_unbonded_kill(*num_slashing_spans)
)]
pub fn withdraw_unbonded(
origin: OriginFor<T>,
member_account: AccountIdLookupOf<T>,
num_slashing_spans: u32,
) -> DispatchResultWithPostInfo {
let caller = ensure_signed(origin)?;
let member_account = T::Lookup::lookup(member_account)?;
let mut member =
PoolMembers::<T>::get(&member_account).ok_or(Error::<T>::PoolMemberNotFound)?;
let current_era = T::Staking::current_era();
let bonded_pool = BondedPool::<T>::get(member.pool_id)
.defensive_ok_or::<Error<T>>(DefensiveError::PoolNotFound.into())?;
let mut sub_pools =
SubPoolsStorage::<T>::get(member.pool_id).ok_or(Error::<T>::SubPoolsNotFound)?;
bonded_pool.ok_to_withdraw_unbonded_with(&caller, &member_account)?;
// NOTE: must do this after we have done the `ok_to_withdraw_unbonded_other_with` check.
let withdrawn_points = member.withdraw_unlocked(current_era);
ensure!(!withdrawn_points.is_empty(), Error::<T>::CannotWithdrawAny);
// Before calculating the `balance_to_unbond`, we call withdraw unbonded to ensure the
// `transferrable_balance` is correct.
let stash_killed =
T::Staking::withdraw_unbonded(bonded_pool.bonded_account(), num_slashing_spans)?;
// defensive-only: the depositor puts enough funds into the stash so that it will only
// be destroyed when they are leaving.
ensure!(
!stash_killed || caller == bonded_pool.roles.depositor,
Error::<T>::Defensive(DefensiveError::BondedStashKilledPrematurely)
);
let mut sum_unlocked_points: BalanceOf<T> = Zero::zero();
let balance_to_unbond = withdrawn_points
.iter()
.fold(BalanceOf::<T>::zero(), |accumulator, (era, unlocked_points)| {
sum_unlocked_points = sum_unlocked_points.saturating_add(*unlocked_points);
if let Some(era_pool) = sub_pools.with_era.get_mut(era) {
let balance_to_unbond = era_pool.dissolve(*unlocked_points);
if era_pool.points.is_zero() {
sub_pools.with_era.remove(era);
}
accumulator.saturating_add(balance_to_unbond)
} else {
// A pool does not belong to this era, so it must have been merged to the
// era-less pool.
accumulator.saturating_add(sub_pools.no_era.dissolve(*unlocked_points))
}
})
// A call to this transaction may cause the pool's stash to get dusted. If this
// happens before the last member has withdrawn, then all subsequent withdraws will
// be 0. However the unbond pools do no get updated to reflect this. In the
// aforementioned scenario, this check ensures we don't try to withdraw funds that
// don't exist. This check is also defensive in cases where the unbond pool does not
// update its balance (e.g. a bug in the slashing hook.) We gracefully proceed in
// order to ensure members can leave the pool and it can be destroyed.
.min(bonded_pool.transferrable_balance());
T::Currency::transfer(
&bonded_pool.bonded_account(),
&member_account,
balance_to_unbond,
ExistenceRequirement::AllowDeath,
)
.defensive()?;
Self::deposit_event(Event::<T>::Withdrawn {
member: member_account.clone(),
pool_id: member.pool_id,
points: sum_unlocked_points,
balance: balance_to_unbond,
});
let post_info_weight = if member.total_points().is_zero() {
// remove any `ClaimPermission` associated with the member.
ClaimPermissions::<T>::remove(&member_account);
// member being reaped.
PoolMembers::<T>::remove(&member_account);
Self::deposit_event(Event::<T>::MemberRemoved {
pool_id: member.pool_id,
member: member_account.clone(),
});
if member_account == bonded_pool.roles.depositor {
Pallet::<T>::dissolve_pool(bonded_pool);
None
} else {
bonded_pool.dec_members().put();
SubPoolsStorage::<T>::insert(member.pool_id, sub_pools);
Some(T::WeightInfo::withdraw_unbonded_update(num_slashing_spans))
}
} else {
// we certainly don't need to delete any pools, because no one is being removed.
SubPoolsStorage::<T>::insert(member.pool_id, sub_pools);
PoolMembers::<T>::insert(&member_account, member);
Some(T::WeightInfo::withdraw_unbonded_update(num_slashing_spans))
};
Ok(post_info_weight.into())
}
/// Create a new delegation pool.
///
/// # Arguments
///
/// * `amount` - The amount of funds to delegate to the pool. This also acts of a sort of
/// deposit since the pools creator cannot fully unbond funds until the pool is being
/// destroyed.
/// * `index` - A disambiguation index for creating the account. Likely only useful when
/// creating multiple pools in the same extrinsic.
/// * `root` - The account to set as [`PoolRoles::root`].
/// * `nominator` - The account to set as the [`PoolRoles::nominator`].
/// * `bouncer` - The account to set as the [`PoolRoles::bouncer`].
///
/// # Note
///
/// In addition to `amount`, the caller will transfer the existential deposit; so the caller
/// needs at have at least `amount + existential_deposit` transferrable.
#[pallet::call_index(6)]
#[pallet::weight(T::WeightInfo::create())]
pub fn create(
origin: OriginFor<T>,
#[pallet::compact] amount: BalanceOf<T>,
root: AccountIdLookupOf<T>,
nominator: AccountIdLookupOf<T>,
bouncer: AccountIdLookupOf<T>,
) -> DispatchResult {
let depositor = ensure_signed(origin)?;
let pool_id = LastPoolId::<T>::try_mutate::<_, Error<T>, _>(|id| {
*id = id.checked_add(1).ok_or(Error::<T>::OverflowRisk)?;
Ok(*id)
})?;
Self::do_create(depositor, amount, root, nominator, bouncer, pool_id)
}
/// Create a new delegation pool with a previously used pool id
///
/// # Arguments
///
/// same as `create` with the inclusion of
/// * `pool_id` - `A valid PoolId.
#[pallet::call_index(7)]
#[pallet::weight(T::WeightInfo::create())]
pub fn create_with_pool_id(
origin: OriginFor<T>,
#[pallet::compact] amount: BalanceOf<T>,
root: AccountIdLookupOf<T>,
nominator: AccountIdLookupOf<T>,
bouncer: AccountIdLookupOf<T>,
pool_id: PoolId,
) -> DispatchResult {
let depositor = ensure_signed(origin)?;
ensure!(!BondedPools::<T>::contains_key(pool_id), Error::<T>::PoolIdInUse);
ensure!(pool_id < LastPoolId::<T>::get(), Error::<T>::InvalidPoolId);
Self::do_create(depositor, amount, root, nominator, bouncer, pool_id)
}
/// Nominate on behalf of the pool.
///
/// The dispatch origin of this call must be signed by the pool nominator or the pool
/// root role.
///
/// This directly forward the call to the staking pallet, on behalf of the pool bonded
/// account.
#[pallet::call_index(8)]
#[pallet::weight(T::WeightInfo::nominate(validators.len() as u32))]
pub fn nominate(
origin: OriginFor<T>,
pool_id: PoolId,
validators: Vec<T::AccountId>,
) -> DispatchResult {
let who = ensure_signed(origin)?;
let bonded_pool = BondedPool::<T>::get(pool_id).ok_or(Error::<T>::PoolNotFound)?;
ensure!(bonded_pool.can_nominate(&who), Error::<T>::NotNominator);
T::Staking::nominate(&bonded_pool.bonded_account(), validators)
}
/// Set a new state for the pool.
///
/// If a pool is already in the `Destroying` state, then under no condition can its state
/// change again.
///
/// The dispatch origin of this call must be either:
///
/// 1. signed by the bouncer, or the root role of the pool,
/// 2. if the pool conditions to be open are NOT met (as described by `ok_to_be_open`), and
/// then the state of the pool can be permissionlessly changed to `Destroying`.
#[pallet::call_index(9)]
#[pallet::weight(T::WeightInfo::set_state())]
pub fn set_state(
origin: OriginFor<T>,
pool_id: PoolId,
state: PoolState,
) -> DispatchResult {
let who = ensure_signed(origin)?;
let mut bonded_pool = BondedPool::<T>::get(pool_id).ok_or(Error::<T>::PoolNotFound)?;
ensure!(bonded_pool.state != PoolState::Destroying, Error::<T>::CanNotChangeState);
if bonded_pool.can_toggle_state(&who) {
bonded_pool.set_state(state);
} else if bonded_pool.ok_to_be_open().is_err() && state == PoolState::Destroying {
// If the pool has bad properties, then anyone can set it as destroying
bonded_pool.set_state(PoolState::Destroying);
} else {
Err(Error::<T>::CanNotChangeState)?;
}
bonded_pool.put();
Ok(())
}
/// Set a new metadata for the pool.
///
/// The dispatch origin of this call must be signed by the bouncer, or the root role of the
/// pool.
#[pallet::call_index(10)]
#[pallet::weight(T::WeightInfo::set_metadata(metadata.len() as u32))]
pub fn set_metadata(
origin: OriginFor<T>,
pool_id: PoolId,
metadata: Vec<u8>,
) -> DispatchResult {
let who = ensure_signed(origin)?;
let metadata: BoundedVec<_, _> =
metadata.try_into().map_err(|_| Error::<T>::MetadataExceedsMaxLen)?;
ensure!(
BondedPool::<T>::get(pool_id)
.ok_or(Error::<T>::PoolNotFound)?
.can_set_metadata(&who),
Error::<T>::DoesNotHavePermission
);
Metadata::<T>::mutate(pool_id, |pool_meta| *pool_meta = metadata);
Ok(())
}
/// Update configurations for the nomination pools. The origin for this call must be
/// Root.
///
/// # Arguments
///
/// * `min_join_bond` - Set [`MinJoinBond`].
/// * `min_create_bond` - Set [`MinCreateBond`].
/// * `max_pools` - Set [`MaxPools`].
/// * `max_members` - Set [`MaxPoolMembers`].
/// * `max_members_per_pool` - Set [`MaxPoolMembersPerPool`].
/// * `global_max_commission` - Set [`GlobalMaxCommission`].
#[pallet::call_index(11)]
#[pallet::weight(T::WeightInfo::set_configs())]
pub fn set_configs(
origin: OriginFor<T>,
min_join_bond: ConfigOp<BalanceOf<T>>,
min_create_bond: ConfigOp<BalanceOf<T>>,
max_pools: ConfigOp<u32>,
max_members: ConfigOp<u32>,
max_members_per_pool: ConfigOp<u32>,
global_max_commission: ConfigOp<Perbill>,
) -> DispatchResult {
ensure_root(origin)?;
macro_rules! config_op_exp {
($storage:ty, $op:ident) => {
match $op {
ConfigOp::Noop => (),
ConfigOp::Set(v) => <$storage>::put(v),
ConfigOp::Remove => <$storage>::kill(),
}
};
}
config_op_exp!(MinJoinBond::<T>, min_join_bond);
config_op_exp!(MinCreateBond::<T>, min_create_bond);
config_op_exp!(MaxPools::<T>, max_pools);
config_op_exp!(MaxPoolMembers::<T>, max_members);
config_op_exp!(MaxPoolMembersPerPool::<T>, max_members_per_pool);
config_op_exp!(GlobalMaxCommission::<T>, global_max_commission);
Ok(())
}
/// Update the roles of the pool.
///
/// The root is the only entity that can change any of the roles, including itself,
/// excluding the depositor, who can never change.
///
/// It emits an event, notifying UIs of the role change. This event is quite relevant to
/// most pool members and they should be informed of changes to pool roles.
#[pallet::call_index(12)]
#[pallet::weight(T::WeightInfo::update_roles())]
pub fn update_roles(
origin: OriginFor<T>,
pool_id: PoolId,
new_root: ConfigOp<T::AccountId>,
new_nominator: ConfigOp<T::AccountId>,
new_bouncer: ConfigOp<T::AccountId>,
) -> DispatchResult {
let mut bonded_pool = match ensure_root(origin.clone()) {
Ok(()) => BondedPool::<T>::get(pool_id).ok_or(Error::<T>::PoolNotFound)?,
Err(frame_support::error::BadOrigin) => {
let who = ensure_signed(origin)?;
let bonded_pool =
BondedPool::<T>::get(pool_id).ok_or(Error::<T>::PoolNotFound)?;
ensure!(bonded_pool.can_update_roles(&who), Error::<T>::DoesNotHavePermission);
bonded_pool
},
};
match new_root {
ConfigOp::Noop => (),
ConfigOp::Remove => bonded_pool.roles.root = None,
ConfigOp::Set(v) => bonded_pool.roles.root = Some(v),
};
match new_nominator {
ConfigOp::Noop => (),
ConfigOp::Remove => bonded_pool.roles.nominator = None,
ConfigOp::Set(v) => bonded_pool.roles.nominator = Some(v),
};
match new_bouncer {
ConfigOp::Noop => (),
ConfigOp::Remove => bonded_pool.roles.bouncer = None,
ConfigOp::Set(v) => bonded_pool.roles.bouncer = Some(v),
};
Self::deposit_event(Event::<T>::RolesUpdated {
root: bonded_pool.roles.root.clone(),
nominator: bonded_pool.roles.nominator.clone(),
bouncer: bonded_pool.roles.bouncer.clone(),
});
bonded_pool.put();
Ok(())
}
/// Chill on behalf of the pool.
///
/// The dispatch origin of this call must be signed by the pool nominator or the pool
/// root role, same as [`Pallet::nominate`].
///
/// This directly forward the call to the staking pallet, on behalf of the pool bonded
/// account.
#[pallet::call_index(13)]
#[pallet::weight(T::WeightInfo::chill())]
pub fn chill(origin: OriginFor<T>, pool_id: PoolId) -> DispatchResult {
let who = ensure_signed(origin)?;
let bonded_pool = BondedPool::<T>::get(pool_id).ok_or(Error::<T>::PoolNotFound)?;
ensure!(bonded_pool.can_nominate(&who), Error::<T>::NotNominator);
T::Staking::chill(&bonded_pool.bonded_account())
}
/// `origin` bonds funds from `extra` for some pool member `member` into their respective
/// pools.
///
/// `origin` can bond extra funds from free balance or pending rewards when `origin ==
/// other`.
///
/// In the case of `origin != other`, `origin` can only bond extra pending rewards of
/// `other` members assuming set_claim_permission for the given member is
/// `PermissionlessAll` or `PermissionlessCompound`.
#[pallet::call_index(14)]
#[pallet::weight(
T::WeightInfo::bond_extra_transfer()
.max(T::WeightInfo::bond_extra_other())
)]
pub fn bond_extra_other(
origin: OriginFor<T>,
member: AccountIdLookupOf<T>,
extra: BondExtra<BalanceOf<T>>,
) -> DispatchResult {
let who = ensure_signed(origin)?;
Self::do_bond_extra(who, T::Lookup::lookup(member)?, extra)
}
/// Allows a pool member to set a claim permission to allow or disallow permissionless
/// bonding and withdrawing.
///
/// By default, this is `Permissioned`, which implies only the pool member themselves can
/// claim their pending rewards. If a pool member wishes so, they can set this to
/// `PermissionlessAll` to allow any account to claim their rewards and bond extra to the
/// pool.
///
/// # Arguments
///
/// * `origin` - Member of a pool.
/// * `actor` - Account to claim reward. // improve this
#[pallet::call_index(15)]
#[pallet::weight(T::DbWeight::get().reads_writes(1, 1))]
pub fn set_claim_permission(
origin: OriginFor<T>,
permission: ClaimPermission,
) -> DispatchResult {
let who = ensure_signed(origin)?;
ensure!(PoolMembers::<T>::contains_key(&who), Error::<T>::PoolMemberNotFound);
ClaimPermissions::<T>::mutate(who, |source| {
*source = permission;
});
Ok(())
}
/// `origin` can claim payouts on some pool member `other`'s behalf.
///
/// Pool member `other` must have a `PermissionlessAll` or `PermissionlessWithdraw` in order
/// for this call to be successful.
#[pallet::call_index(16)]
#[pallet::weight(T::WeightInfo::claim_payout())]
pub fn claim_payout_other(origin: OriginFor<T>, other: T::AccountId) -> DispatchResult {
let signer = ensure_signed(origin)?;
Self::do_claim_payout(signer, other)
}
/// Set the commission of a pool.
//
/// Both a commission percentage and a commission payee must be provided in the `current`
/// tuple. Where a `current` of `None` is provided, any current commission will be removed.
///
/// - If a `None` is supplied to `new_commission`, existing commission will be removed.
#[pallet::call_index(17)]
#[pallet::weight(T::WeightInfo::set_commission())]
pub fn set_commission(
origin: OriginFor<T>,
pool_id: PoolId,
new_commission: Option<(Perbill, T::AccountId)>,
) -> DispatchResult {
let who = ensure_signed(origin)?;
let mut bonded_pool = BondedPool::<T>::get(pool_id).ok_or(Error::<T>::PoolNotFound)?;
ensure!(bonded_pool.can_manage_commission(&who), Error::<T>::DoesNotHavePermission);
let mut reward_pool = RewardPools::<T>::get(pool_id)
.defensive_ok_or::<Error<T>>(DefensiveError::RewardPoolNotFound.into())?;
// IMPORTANT: make sure that everything up to this point is using the current commission
// before it updates. Note that `try_update_current` could still fail at this point.
reward_pool.update_records(
pool_id,
bonded_pool.points,
bonded_pool.commission.current(),
)?;
RewardPools::insert(pool_id, reward_pool);
bonded_pool.commission.try_update_current(&new_commission)?;
bonded_pool.put();
Self::deposit_event(Event::<T>::PoolCommissionUpdated {
pool_id,
current: new_commission,
});
Ok(())
}
/// Set the maximum commission of a pool.
///
/// - Initial max can be set to any `Perbill`, and only smaller values thereafter.
/// - Current commission will be lowered in the event it is higher than a new max
/// commission.
#[pallet::call_index(18)]
#[pallet::weight(T::WeightInfo::set_commission_max())]
pub fn set_commission_max(
origin: OriginFor<T>,
pool_id: PoolId,
max_commission: Perbill,
) -> DispatchResult {
let who = ensure_signed(origin)?;
let mut bonded_pool = BondedPool::<T>::get(pool_id).ok_or(Error::<T>::PoolNotFound)?;
ensure!(bonded_pool.can_manage_commission(&who), Error::<T>::DoesNotHavePermission);
bonded_pool.commission.try_update_max(pool_id, max_commission)?;
bonded_pool.put();
Self::deposit_event(Event::<T>::PoolMaxCommissionUpdated { pool_id, max_commission });
Ok(())
}
/// Set the commission change rate for a pool.
///
/// Initial change rate is not bounded, whereas subsequent updates can only be more
/// restrictive than the current.
#[pallet::call_index(19)]
#[pallet::weight(T::WeightInfo::set_commission_change_rate())]
pub fn set_commission_change_rate(
origin: OriginFor<T>,
pool_id: PoolId,
change_rate: CommissionChangeRate<BlockNumberFor<T>>,
) -> DispatchResult {
let who = ensure_signed(origin)?;
let mut bonded_pool = BondedPool::<T>::get(pool_id).ok_or(Error::<T>::PoolNotFound)?;
ensure!(bonded_pool.can_manage_commission(&who), Error::<T>::DoesNotHavePermission);
bonded_pool.commission.try_update_change_rate(change_rate)?;
bonded_pool.put();
Self::deposit_event(Event::<T>::PoolCommissionChangeRateUpdated {
pool_id,
change_rate,
});
Ok(())
}
/// Claim pending commission.
///
/// The dispatch origin of this call must be signed by the `root` role of the pool. Pending
/// commission is paid out and added to total claimed commission`. Total pending commission
/// is reset to zero. the current.
#[pallet::call_index(20)]
#[pallet::weight(T::WeightInfo::claim_commission())]
pub fn claim_commission(origin: OriginFor<T>, pool_id: PoolId) -> DispatchResult {
let who = ensure_signed(origin)?;
Self::do_claim_commission(who, pool_id)
}
}
#[pallet::hooks]
impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
#[cfg(feature = "try-runtime")]
fn try_state(_n: BlockNumberFor<T>) -> Result<(), TryRuntimeError> {
Self::do_try_state(u8::MAX)
}
fn integrity_test() {
assert!(
T::MaxPointsToBalance::get() > 0,
"Minimum points to balance ratio must be greater than 0"
);
assert!(
T::Staking::bonding_duration() < TotalUnbondingPools::<T>::get(),
"There must be more unbonding pools then the bonding duration /
so a slash can be applied to relevant unboding pools. (We assume /
the bonding duration > slash deffer duration.",
);
}
}
}
impl<T: Config> Pallet<T> {
/// The amount of bond that MUST REMAIN IN BONDED in ALL POOLS.
///
/// It is the responsibility of the depositor to put these funds into the pool initially. Upon
/// unbond, they can never unbond to a value below this amount.
///
/// It is essentially `max { MinNominatorBond, MinCreateBond, MinJoinBond }`, where the former
/// is coming from the staking pallet and the latter two are configured in this pallet.
pub fn depositor_min_bond() -> BalanceOf<T> {
T::Staking::minimum_nominator_bond()
.max(MinCreateBond::<T>::get())
.max(MinJoinBond::<T>::get())
.max(T::Currency::minimum_balance())
}
/// Remove everything related to the given bonded pool.
///
/// Metadata and all of the sub-pools are also deleted. All accounts are dusted and the leftover
/// of the reward account is returned to the depositor.
pub fn dissolve_pool(bonded_pool: BondedPool<T>) {
let reward_account = bonded_pool.reward_account();
let bonded_account = bonded_pool.bonded_account();
ReversePoolIdLookup::<T>::remove(&bonded_account);
RewardPools::<T>::remove(bonded_pool.id);
SubPoolsStorage::<T>::remove(bonded_pool.id);
// Kill accounts from storage by making their balance go below ED. We assume that the
// accounts have no references that would prevent destruction once we get to this point. We
// don't work with the system pallet directly, but
// 1. we drain the reward account and kill it. This account should never have any extra
// consumers anyway.
// 2. the bonded account should become a 'killed stash' in the staking system, and all of
// its consumers removed.
debug_assert_eq!(frame_system::Pallet::<T>::consumers(&reward_account), 0);
debug_assert_eq!(frame_system::Pallet::<T>::consumers(&bonded_account), 0);
debug_assert_eq!(
T::Staking::total_stake(&bonded_account).unwrap_or_default(),
Zero::zero()
);
// This shouldn't fail, but if it does we don't really care. Remaining balance can consist
// of unclaimed pending commission, errorneous transfers to the reward account, etc.
let reward_pool_remaining = T::Currency::free_balance(&reward_account);
let _ = T::Currency::transfer(
&reward_account,
&bonded_pool.roles.depositor,
reward_pool_remaining,
ExistenceRequirement::AllowDeath,
);
// NOTE: this is purely defensive.
T::Currency::make_free_balance_be(&reward_account, Zero::zero());
T::Currency::make_free_balance_be(&bonded_pool.bonded_account(), Zero::zero());
Self::deposit_event(Event::<T>::Destroyed { pool_id: bonded_pool.id });
// Remove bonded pool metadata.
Metadata::<T>::remove(bonded_pool.id);
bonded_pool.remove();
}
/// Create the main, bonded account of a pool with the given id.
pub fn create_bonded_account(id: PoolId) -> T::AccountId {
T::PalletId::get().into_sub_account_truncating((AccountType::Bonded, id))
}
/// Create the reward account of a pool with the given id.
pub fn create_reward_account(id: PoolId) -> T::AccountId {
// NOTE: in order to have a distinction in the test account id type (u128), we put
// account_type first so it does not get truncated out.
T::PalletId::get().into_sub_account_truncating((AccountType::Reward, id))
}
/// Get the member with their associated bonded and reward pool.
fn get_member_with_pools(
who: &T::AccountId,
) -> Result<(PoolMember<T>, BondedPool<T>, RewardPool<T>), Error<T>> {
let member = PoolMembers::<T>::get(who).ok_or(Error::<T>::PoolMemberNotFound)?;
let bonded_pool =
BondedPool::<T>::get(member.pool_id).defensive_ok_or(DefensiveError::PoolNotFound)?;
let reward_pool =
RewardPools::<T>::get(member.pool_id).defensive_ok_or(DefensiveError::PoolNotFound)?;
Ok((member, bonded_pool, reward_pool))
}
/// Persist the member with their associated bonded and reward pool into storage, consuming
/// all of them.
fn put_member_with_pools(
member_account: &T::AccountId,
member: PoolMember<T>,
bonded_pool: BondedPool<T>,
reward_pool: RewardPool<T>,
) {
bonded_pool.put();
RewardPools::insert(member.pool_id, reward_pool);
PoolMembers::<T>::insert(member_account, member);
}
/// Calculate the equivalent point of `new_funds` in a pool with `current_balance` and
/// `current_points`.
fn balance_to_point(
current_balance: BalanceOf<T>,
current_points: BalanceOf<T>,
new_funds: BalanceOf<T>,
) -> BalanceOf<T> {
let u256 = T::BalanceToU256::convert;
let balance = T::U256ToBalance::convert;
match (current_balance.is_zero(), current_points.is_zero()) {
(_, true) => new_funds.saturating_mul(POINTS_TO_BALANCE_INIT_RATIO.into()),
(true, false) => {
// The pool was totally slashed.
// This is the equivalent of `(current_points / 1) * new_funds`.
new_funds.saturating_mul(current_points)
},
(false, false) => {
// Equivalent to (current_points / current_balance) * new_funds
balance(
u256(current_points)
.saturating_mul(u256(new_funds))
// We check for zero above
.div(u256(current_balance)),
)
},
}
}
/// Calculate the equivalent balance of `points` in a pool with `current_balance` and
/// `current_points`.
fn point_to_balance(
current_balance: BalanceOf<T>,
current_points: BalanceOf<T>,
points: BalanceOf<T>,
) -> BalanceOf<T> {
let u256 = T::BalanceToU256::convert;
let balance = T::U256ToBalance::convert;
if current_balance.is_zero() || current_points.is_zero() || points.is_zero() {
// There is nothing to unbond
return Zero::zero()
}
// Equivalent of (current_balance / current_points) * points
balance(u256(current_balance).saturating_mul(u256(points)))
// We check for zero above
.div(current_points)
}
/// If the member has some rewards, transfer a payout from the reward pool to the member.
// Emits events and potentially modifies pool state if any arithmetic saturates, but does
// not persist any of the mutable inputs to storage.
fn do_reward_payout(
member_account: &T::AccountId,
member: &mut PoolMember<T>,
bonded_pool: &mut BondedPool<T>,
reward_pool: &mut RewardPool<T>,
) -> Result<BalanceOf<T>, DispatchError> {
debug_assert_eq!(member.pool_id, bonded_pool.id);
// a member who has no skin in the game anymore cannot claim any rewards.
ensure!(!member.active_points().is_zero(), Error::<T>::FullyUnbonding);
let (current_reward_counter, _) = reward_pool.current_reward_counter(
bonded_pool.id,
bonded_pool.points,
bonded_pool.commission.current(),
)?;
// Determine the pending rewards. In scenarios where commission is 100%, `pending_rewards`
// will be zero.
let pending_rewards = member.pending_rewards(current_reward_counter)?;
if pending_rewards.is_zero() {
return Ok(pending_rewards)
}
// IFF the reward is non-zero alter the member and reward pool info.
member.last_recorded_reward_counter = current_reward_counter;
reward_pool.register_claimed_reward(pending_rewards);
T::Currency::transfer(
&bonded_pool.reward_account(),
member_account,
pending_rewards,
// defensive: the depositor has put existential deposit into the pool and it stays
// untouched, reward account shall not die.
ExistenceRequirement::KeepAlive,
)?;
Self::deposit_event(Event::<T>::PaidOut {
member: member_account.clone(),
pool_id: member.pool_id,
payout: pending_rewards,
});
Ok(pending_rewards)
}
fn do_create(
who: T::AccountId,
amount: BalanceOf<T>,
root: AccountIdLookupOf<T>,
nominator: AccountIdLookupOf<T>,
bouncer: AccountIdLookupOf<T>,
pool_id: PoolId,
) -> DispatchResult {
let root = T::Lookup::lookup(root)?;
let nominator = T::Lookup::lookup(nominator)?;
let bouncer = T::Lookup::lookup(bouncer)?;
ensure!(amount >= Pallet::<T>::depositor_min_bond(), Error::<T>::MinimumBondNotMet);
ensure!(
MaxPools::<T>::get().map_or(true, |max_pools| BondedPools::<T>::count() < max_pools),
Error::<T>::MaxPools
);
ensure!(!PoolMembers::<T>::contains_key(&who), Error::<T>::AccountBelongsToOtherPool);
let mut bonded_pool = BondedPool::<T>::new(
pool_id,
PoolRoles {
root: Some(root),
nominator: Some(nominator),
bouncer: Some(bouncer),
depositor: who.clone(),
},
);
bonded_pool.try_inc_members()?;
let points = bonded_pool.try_bond_funds(&who, amount, BondType::Create)?;
T::Currency::transfer(
&who,
&bonded_pool.reward_account(),
T::Currency::minimum_balance(),
ExistenceRequirement::AllowDeath,
)?;
PoolMembers::<T>::insert(
who.clone(),
PoolMember::<T> {
pool_id,
points,
last_recorded_reward_counter: Zero::zero(),
unbonding_eras: Default::default(),
},
);
RewardPools::<T>::insert(
pool_id,
RewardPool::<T> {
last_recorded_reward_counter: Zero::zero(),
last_recorded_total_payouts: Zero::zero(),
total_rewards_claimed: Zero::zero(),
total_commission_pending: Zero::zero(),
total_commission_claimed: Zero::zero(),
},
);
ReversePoolIdLookup::<T>::insert(bonded_pool.bonded_account(), pool_id);
Self::deposit_event(Event::<T>::Created { depositor: who.clone(), pool_id });
Self::deposit_event(Event::<T>::Bonded {
member: who,
pool_id,
bonded: amount,
joined: true,
});
bonded_pool.put();
Ok(())
}
fn do_bond_extra(
signer: T::AccountId,
who: T::AccountId,
extra: BondExtra<BalanceOf<T>>,
) -> DispatchResult {
if signer != who {
ensure!(
ClaimPermissions::<T>::get(&who).can_bond_extra(),
Error::<T>::DoesNotHavePermission
);
ensure!(extra == BondExtra::Rewards, Error::<T>::BondExtraRestricted);
}
let (mut member, mut bonded_pool, mut reward_pool) = Self::get_member_with_pools(&who)?;
// payout related stuff: we must claim the payouts, and updated recorded payout data
// before updating the bonded pool points, similar to that of `join` transaction.
reward_pool.update_records(
bonded_pool.id,
bonded_pool.points,
bonded_pool.commission.current(),
)?;
let claimed =
Self::do_reward_payout(&who, &mut member, &mut bonded_pool, &mut reward_pool)?;
let (points_issued, bonded) = match extra {
BondExtra::FreeBalance(amount) =>
(bonded_pool.try_bond_funds(&who, amount, BondType::Later)?, amount),
BondExtra::Rewards =>
(bonded_pool.try_bond_funds(&who, claimed, BondType::Later)?, claimed),
};
bonded_pool.ok_to_be_open()?;
member.points =
member.points.checked_add(&points_issued).ok_or(Error::<T>::OverflowRisk)?;
Self::deposit_event(Event::<T>::Bonded {
member: who.clone(),
pool_id: member.pool_id,
bonded,
joined: false,
});
Self::put_member_with_pools(&who, member, bonded_pool, reward_pool);
Ok(())
}
fn do_claim_commission(who: T::AccountId, pool_id: PoolId) -> DispatchResult {
let bonded_pool = BondedPool::<T>::get(pool_id).ok_or(Error::<T>::PoolNotFound)?;
ensure!(bonded_pool.can_manage_commission(&who), Error::<T>::DoesNotHavePermission);
let mut reward_pool = RewardPools::<T>::get(pool_id)
.defensive_ok_or::<Error<T>>(DefensiveError::RewardPoolNotFound.into())?;
// IMPORTANT: make sure that any newly pending commission not yet processed is added to
// `total_commission_pending`.
reward_pool.update_records(
pool_id,
bonded_pool.points,
bonded_pool.commission.current(),
)?;
let commission = reward_pool.total_commission_pending;
ensure!(!commission.is_zero(), Error::<T>::NoPendingCommission);
let payee = bonded_pool
.commission
.current
.as_ref()
.map(|(_, p)| p.clone())
.ok_or(Error::<T>::NoCommissionCurrentSet)?;
// Payout claimed commission.
T::Currency::transfer(
&bonded_pool.reward_account(),
&payee,
commission,
ExistenceRequirement::KeepAlive,
)?;
// Add pending commission to total claimed counter.
reward_pool.total_commission_claimed =
reward_pool.total_commission_claimed.saturating_add(commission);
// Reset total pending commission counter to zero.
reward_pool.total_commission_pending = Zero::zero();
// Commit reward pool updates
RewardPools::<T>::insert(pool_id, reward_pool);
Self::deposit_event(Event::<T>::PoolCommissionClaimed { pool_id, commission });
Ok(())
}
fn do_claim_payout(signer: T::AccountId, who: T::AccountId) -> DispatchResult {
if signer != who {
ensure!(
ClaimPermissions::<T>::get(&who).can_claim_payout(),
Error::<T>::DoesNotHavePermission
);
}
let (mut member, mut bonded_pool, mut reward_pool) = Self::get_member_with_pools(&who)?;
let _ = Self::do_reward_payout(&who, &mut member, &mut bonded_pool, &mut reward_pool)?;
Self::put_member_with_pools(&who, member, bonded_pool, reward_pool);
Ok(())
}
/// Ensure the correctness of the state of this pallet.
///
/// This should be valid before or after each state transition of this pallet.
///
/// ## Invariants:
///
/// First, let's consider pools:
///
/// * `BondedPools` and `RewardPools` must all have the EXACT SAME key-set.
/// * `SubPoolsStorage` must be a subset of the above superset.
/// * `Metadata` keys must be a subset of the above superset.
/// * the count of the above set must be less than `MaxPools`.
///
/// Then, considering members as well:
///
/// * each `BondedPool.member_counter` must be:
/// - correct (compared to actual count of member who have `.pool_id` this pool)
/// - less than `MaxPoolMembersPerPool`.
/// * each `member.pool_id` must correspond to an existing `BondedPool.id` (which implies the
/// existence of the reward pool as well).
/// * count of all members must be less than `MaxPoolMembers`.
///
/// Then, considering unbonding members:
///
/// for each pool:
/// * sum of the balance that's tracked in all unbonding pools must be the same as the
/// unbonded balance of the main account, as reported by the staking interface.
/// * sum of the balance that's tracked in all unbonding pools, plus the bonded balance of the
/// main account should be less than or qual to the total balance of the main account.
///
/// ## Sanity check level
///
/// To cater for tests that want to escape parts of these checks, this function is split into
/// multiple `level`s, where the higher the level, the more checks we performs. So,
/// `try_state(255)` is the strongest sanity check, and `0` performs no checks.
#[cfg(any(feature = "try-runtime", feature = "fuzzing", test, debug_assertions))]
pub fn do_try_state(level: u8) -> Result<(), TryRuntimeError> {
if level.is_zero() {
return Ok(())
}
// note: while a bit wacky, since they have the same key, even collecting to vec should
// result in the same set of keys, in the same order.
let bonded_pools = BondedPools::<T>::iter_keys().collect::<Vec<_>>();
let reward_pools = RewardPools::<T>::iter_keys().collect::<Vec<_>>();
ensure!(
bonded_pools == reward_pools,
"`BondedPools` and `RewardPools` must all have the EXACT SAME key-set."
);
ensure!(
SubPoolsStorage::<T>::iter_keys().all(|k| bonded_pools.contains(&k)),
"`SubPoolsStorage` must be a subset of the above superset."
);
ensure!(
Metadata::<T>::iter_keys().all(|k| bonded_pools.contains(&k)),
"`Metadata` keys must be a subset of the above superset."
);
ensure!(
MaxPools::<T>::get().map_or(true, |max| bonded_pools.len() <= (max as usize)),
Error::<T>::MaxPools
);
for id in reward_pools {
let account = Self::create_reward_account(id);
if T::Currency::free_balance(&account) < T::Currency::minimum_balance() {
log!(
warn,
"reward pool of {:?}: {:?} (ed = {:?}), should only happen because ED has \
changed recently. Pool operators should be notified to top up the reward \
account",
id,
T::Currency::free_balance(&account),
T::Currency::minimum_balance(),
)
}
}
let mut pools_members = BTreeMap::<PoolId, u32>::new();
let mut pools_members_pending_rewards = BTreeMap::<PoolId, BalanceOf<T>>::new();
let mut all_members = 0u32;
PoolMembers::<T>::iter().try_for_each(|(_, d)| -> Result<(), TryRuntimeError> {
let bonded_pool = BondedPools::<T>::get(d.pool_id).unwrap();
ensure!(!d.total_points().is_zero(), "No member should have zero points");
*pools_members.entry(d.pool_id).or_default() += 1;
all_members += 1;
let reward_pool = RewardPools::<T>::get(d.pool_id).unwrap();
if !bonded_pool.points.is_zero() {
let commission = bonded_pool.commission.current();
let (current_rc, _) = reward_pool
.current_reward_counter(d.pool_id, bonded_pool.points, commission)
.unwrap();
let pending_rewards = d.pending_rewards(current_rc).unwrap();
*pools_members_pending_rewards.entry(d.pool_id).or_default() += pending_rewards;
} // else this pool has been heavily slashed and cannot have any rewards anymore.
Ok(())
})?;
RewardPools::<T>::iter_keys().try_for_each(|id| -> Result<(), TryRuntimeError> {
// the sum of the pending rewards must be less than the leftover balance. Since the
// reward math rounds down, we might accumulate some dust here.
let pending_rewards_lt_leftover_bal = RewardPool::<T>::current_balance(id) >=
pools_members_pending_rewards.get(&id).copied().unwrap_or_default();
if !pending_rewards_lt_leftover_bal {
log::warn!(
"pool {:?}, sum pending rewards = {:?}, remaining balance = {:?}",
id,
pools_members_pending_rewards.get(&id),
RewardPool::<T>::current_balance(id)
);
}
ensure!(
pending_rewards_lt_leftover_bal,
"The sum of the pending rewards must be less than the leftover balance."
);
Ok(())
})?;
BondedPools::<T>::iter().try_for_each(|(id, inner)| -> Result<(), TryRuntimeError> {
let bonded_pool = BondedPool { id, inner };
ensure!(
pools_members.get(&id).copied().unwrap_or_default() ==
bonded_pool.member_counter,
"Each `BondedPool.member_counter` must be equal to the actual count of members of this pool"
);
ensure!(
MaxPoolMembersPerPool::<T>::get()
.map_or(true, |max| bonded_pool.member_counter <= max),
Error::<T>::MaxPoolMembers
);
let depositor = PoolMembers::<T>::get(&bonded_pool.roles.depositor).unwrap();
ensure!(
bonded_pool.is_destroying_and_only_depositor(depositor.active_points()) ||
depositor.active_points() >= MinCreateBond::<T>::get(),
"depositor must always have MinCreateBond stake in the pool, except for when the \
pool is being destroyed and the depositor is the last member",
);
Ok(())
})?;
ensure!(
MaxPoolMembers::<T>::get().map_or(true, |max| all_members <= max),
Error::<T>::MaxPoolMembers
);
if level <= 1 {
return Ok(())
}
for (pool_id, _pool) in BondedPools::<T>::iter() {
let pool_account = Pallet::<T>::create_bonded_account(pool_id);
let subs = SubPoolsStorage::<T>::get(pool_id).unwrap_or_default();
let sum_unbonding_balance = subs.sum_unbonding_balance();
let bonded_balance = T::Staking::active_stake(&pool_account).unwrap_or_default();
let total_balance = T::Currency::total_balance(&pool_account);
assert!(
total_balance >= bonded_balance + sum_unbonding_balance,
"faulty pool: {:?} / {:?}, total_balance {:?} >= bonded_balance {:?} + sum_unbonding_balance {:?}",
pool_id,
_pool,
total_balance,
bonded_balance,
sum_unbonding_balance
);
}
Ok(())
}
/// Fully unbond the shares of `member`, when executed from `origin`.
///
/// This is useful for backwards compatibility with the majority of tests that only deal with
/// full unbonding, not partial unbonding.
#[cfg(any(feature = "runtime-benchmarks", test))]
pub fn fully_unbond(
origin: frame_system::pallet_prelude::OriginFor<T>,
member: T::AccountId,
) -> DispatchResult {
let points = PoolMembers::<T>::get(&member).map(|d| d.active_points()).unwrap_or_default();
let member_lookup = T::Lookup::unlookup(member);
Self::unbond(origin, member_lookup, points)
}
}
impl<T: Config> Pallet<T> {
/// Returns the pending rewards for the specified `who` account.
///
/// In the case of error, `None` is returned. Used by runtime API.
pub fn api_pending_rewards(who: T::AccountId) -> Option<BalanceOf<T>> {
if let Some(pool_member) = PoolMembers::<T>::get(who) {
if let Some((reward_pool, bonded_pool)) = RewardPools::<T>::get(pool_member.pool_id)
.zip(BondedPools::<T>::get(pool_member.pool_id))
{
let commission = bonded_pool.commission.current();
let (current_reward_counter, _) = reward_pool
.current_reward_counter(pool_member.pool_id, bonded_pool.points, commission)
.ok()?;
return pool_member.pending_rewards(current_reward_counter).ok()
}
}
None
}
/// Returns the points to balance conversion for a specified pool.
///
/// If the pool ID does not exist, it returns 0 ratio points to balance. Used by runtime API.
pub fn api_points_to_balance(pool_id: PoolId, points: BalanceOf<T>) -> BalanceOf<T> {
if let Some(pool) = BondedPool::<T>::get(pool_id) {
pool.points_to_balance(points)
} else {
Zero::zero()
}
}
/// Returns the equivalent `new_funds` balance to point conversion for a specified pool.
///
/// If the pool ID does not exist, returns 0 ratio balance to points. Used by runtime API.
pub fn api_balance_to_points(pool_id: PoolId, new_funds: BalanceOf<T>) -> BalanceOf<T> {
if let Some(pool) = BondedPool::<T>::get(pool_id) {
let bonded_balance =
T::Staking::active_stake(&pool.bonded_account()).unwrap_or(Zero::zero());
Pallet::<T>::balance_to_point(bonded_balance, pool.points, new_funds)
} else {
Zero::zero()
}
}
}
impl<T: Config> sp_staking::OnStakingUpdate<T::AccountId, BalanceOf<T>> for Pallet<T> {
fn on_slash(
pool_account: &T::AccountId,
// Bonded balance is always read directly from staking, therefore we don't need to update
// anything here.
slashed_bonded: BalanceOf<T>,
slashed_unlocking: &BTreeMap<EraIndex, BalanceOf<T>>,
) {
if let Some(pool_id) = ReversePoolIdLookup::<T>::get(pool_account) {
let mut sub_pools = match SubPoolsStorage::<T>::get(pool_id).defensive() {
Some(sub_pools) => sub_pools,
None => return,
};
for (era, slashed_balance) in slashed_unlocking.iter() {
if let Some(pool) = sub_pools.with_era.get_mut(era) {
pool.balance = *slashed_balance;
Self::deposit_event(Event::<T>::UnbondingPoolSlashed {
era: *era,
pool_id,
balance: *slashed_balance,
});
}
}
Self::deposit_event(Event::<T>::PoolSlashed { pool_id, balance: slashed_bonded });
SubPoolsStorage::<T>::insert(pool_id, sub_pools);
}
}
}