Crate pallet_liquidity_mining

Expand description

This pallet provides functionality for a liquidity mining program with a time incentive (loyalty factor) and multiple incentives scheme. Users are rewarded for each period they stay in the liq. mining program.

Reward per one period is derived from the user’s loyalty factor which grows with time (periods) the user is in the liq. mining program and the amount of LP shares the user locked into deposit. User’s loyalty factor is reset if the user exits and reenters liquidity mining. User can claim rewards without resetting loyalty factor, only withdrawing shares is penalized by loyalty factor reset. The user is rewarded from the next period after they enters.

Multiple Incentives

This feature allows users to redeposit already deposited LP shares to multiple yield farms and receive incentives from these farms. Deposit in yield farm is called “farm entry”. Maximal number of redepositing same LP shares is configured by variable: MaxFarmEntriesPerDeposit. Set MaxFarmEntriesPerDeposit to 1 to disable multiple incentives scheme. !!!NEVER set this variable to 0. LP shares can be redeposited only to different yield farms running liquidity mining for same pair of assets.

Notes:

LP shares are returned ONLY if deposit is destroyed - withdrawing LP shares can be used to “free slot” for re-lock LP shares to different yield farm. Withdrawing LP shares result in resetting loyalty factor for yield farm user is withdrawing from(other farm entries in the deposit are not affected). If deposit has no more farm entries, deposit is destroyed and LP shares are returned back to user.
YieldFarm - can be in the 3 states: [Active, Stopped, Terminated]
- Active - liquidity mining is running, users are able to deposit, claim and withdraw LP shares. YieldFarm is rewarded from GlobalFarm in this state.
- Stopped - liquidity mining is stopped. Users can claim and withdraw LP shares from the farm. Users CAN’T deposit new LP shares to stopped farm. Stopped farm is not rewarded from the GlobalFarm. Note: stopped farm can be resumed or destroyed.
- Terminated - liquidity mining is ended. User’s CAN’T deposit or claim rewards from stopped farm. Users CAN only withdraw LP shares(without rewards). YieldFarm must be stopped before it can be terminated. Terminated farm stays in the storage until last farm’s entry is withdrawn. Last withdrawn from yield farm will remove terminated farm from the storage. Note: Terminated farm CAN’T be resumed.
GlobalFarm - can be in the 2 states: [Active, Terminated]
- Active - liquidity mining program is running, new yield farms can be added to the global farm.
- Terminated - liquidity mining program is ended. Yield farms can’t be added to the global farm. Global farm MUST be empty(all yield farms in the global farm must be destroyed) before it can be destroyed. Destroying global farm transfer undistributed rewards to farm’s owner. Terminated global farm stay in the storage until all yield farms are removed from the storage. Last yield farm removal from storage triggers global farm removal from storage. Note: Terminated global farm CAN’T be resumed.
Pot - account holding all rewards allocated for all YieldFarms from all GlobalFarms. User’s rewards are transferred from pot’s account to user’s accounts.

Re-exports

pub use pallet::*;

Modules

pallet

The module that hosts all the FRAME types needed to add this pallet to a runtime.

Structs

DefaultPriceAdjustment

Default implementation of PriceAdjustment trait which returns price_adjustment value saved in GlobalFarm.

DepositData

Deposit represents a group of locked LP shares in the liquidity mining program(“Position”). LP shares in the deposit can be locked in one or more yield farms based on pallet’s configuration(MaxEntriesPerDeposit). The LP token’s lock in the deposit is called “farm entry”. Farm entry entitles deposit owner to accumulate rewards from the yield farm. Every deposit should have at least one farm entry and deposit without farm entries should be removed from storage and LP shares should be unlocked. redeposit_lp_shares() is used to add a new farm entry into the deposit(“re-lock” LP shares“).

GlobalFarmData

This struct represents the state a of single liquidity mining program. YieldFarms are rewarded from GlobalFarm based on their stake in GlobalFarm. YieldFarm stake in GlobalFarm is derived from users stake in YieldFarm. Yield farm is considered live from global farm view if yield farm is active or stopped.

LoyaltyCurve

Loyalty curve to calculate loyalty multiplier.

YieldFarmData

YieldFarmEntry