voter-stake-registry/programs/governance-registry/src/account.rs

316 lines
10 KiB
Rust

use crate::error::*;
use anchor_lang::__private::bytemuck::Zeroable;
use anchor_lang::prelude::*;
use anchor_spl::vote_weight_record;
use std::convert::TryFrom;
// Generate a VoteWeightRecord Anchor wrapper, owned by the current program.
// VoteWeightRecords are unique in that they are defined by the SPL governance
// program, but they are actaully owned by this program.
vote_weight_record!(crate::ID);
/// Seconds in one day.
pub const SECS_PER_DAY: i64 = 86_400;
/// Maximum number of days one can lock for.
pub const MAX_DAYS_LOCKED: u64 = 2555;
/// Instance of a voting rights distributor.
#[account(zero_copy)]
pub struct Registrar {
pub authority: Pubkey,
pub realm: Pubkey,
pub realm_community_mint: Pubkey,
pub warmup_secs: i64,
pub bump: u8,
// The length should be adjusted for one's use case.
pub rates: [ExchangeRateEntry; 2],
}
/// User account for minting voting rights.
#[account(zero_copy)]
pub struct Voter {
pub authority: Pubkey,
pub registrar: Pubkey,
pub voter_bump: u8,
pub voter_weight_record_bump: u8,
pub deposits: [DepositEntry; 32],
}
impl Voter {
pub fn weight(&self) -> Result<u64> {
self.deposits
.iter()
.filter(|d| d.is_used)
.try_fold(0, |sum, d| d.voting_power().map(|vp| sum + vp))
}
}
/// Exchange rate for an asset that can be used to mint voting rights.
#[zero_copy]
#[derive(AnchorSerialize, AnchorDeserialize, Default)]
pub struct ExchangeRateEntry {
pub mint: Pubkey,
pub rate: u64,
pub decimals: u8,
}
unsafe impl Zeroable for ExchangeRateEntry {}
/// Bookkeeping for a single deposit for a given mint and lockup schedule.
#[zero_copy]
pub struct DepositEntry {
// True if the deposit entry is being used.
pub is_used: bool,
// Points to the ExchangeRate this deposit uses.
pub rate_idx: u8,
// Amount in the native currency deposited.
pub amount_deposited: u64,
// Amount withdrawn from the deposit in the native currency.
pub amount_withdrawn: u64,
// Amount in the native currency deposited, scaled by the exchange rate.
pub amount_scaled: u64,
// Locked state.
pub lockup: Lockup,
}
impl DepositEntry {
/// # Voting Power Caclulation
///
/// Returns the voting power for the deposit, giving locked tokens boosted
/// voting power that scales linearly with the lockup.
///
/// The minimum lockup period is a single day. The max lockup period is
/// seven years. And so a one day lockup has 1/2 the voting power as a two
/// day lockup, which has 1/2555 the voting power of a 7 year lockup--
/// assuming the amount locked up is equal.
///
/// To achieve this with the SPL governance program--which requires a "max
/// vote weight"--we attach what amounts to a scalar multiplier between 0
/// and 1 to normalize voting power. This multiplier is a function of
/// the lockup schedule. Here we will describe two, a one time
/// cliff and a linear vesting schedule unlocking daily.
///
/// ## Cliff Lockup
///
/// The cliff lockup allows one to lockup their tokens for a set period
/// of time, unlocking all at once on a given date.
///
/// The calculation for this is straight forward
///
/// ```
/// voting_power = (number_days / 2555) * amount
/// ```
///
/// ### Decay
///
/// As time passes, the voting power should decay proportionally, in which
/// case one can substitute for `number_days` the number of days
/// remaining on the lockup.
///
/// ## Daily Vesting Lockup
///
/// Daily vesting can be calculated with simple series sum.
///
/// For the sake of example, suppose we locked up 10 tokens for two days,
/// vesting linearly once a day. In other words, we have 5 tokens locked for
/// 1 day and 5 tokens locked for two days.
///
/// Visually, we can see this in a two year timeline
///
/// 0 5 10 amount unlocked
/// | ---- | ---- |
/// 0 1 2 days
///
/// Then, to calculate the voting power at any time in the first day, we
/// have
///
/// ```
/// voting_power = 1/2555 * 5 + 2/2555 * 5
/// ```
///
/// Notice the scalar multipliers used to normalize the amounts.
/// Since 7 years is the maximum lock, and 1 day is the minimum, we have
/// a scalar of 1/2555 for a one day lock, 2/2555 for a two day lock,
/// 2555/2555 for a 7 year lock, and 0 for no lock.
///
/// We can rewrite the equation above as
///
/// ```
/// voting_power = 1/2555 * 5 + 2/2555 * 5
/// = 1/2555 * 10/2 + 2/2555 * 10/2
/// ```
///
/// Let's now generalize this to a daily vesting schedule over seven years.
/// Let "amount" be the total amount for vesting. Then the total voting
/// power to start is
///
/// ```
/// voting_power = 1/2555*(amount/2555) + 2/2555*(amount/2555) + ... + (2555/2555)*(amount/2555)
/// = 1/2555 * [1*(amount/2555) + 2*(amount/2555) + ... + 2555*(amount/255)]
/// = (1/2555) * (amount/2555) * (1 + 2 + ... + 2555)
/// = (1/2555) * (amount/2555) * [(2555 * [2555 + 1]) / 2]
/// = (1 / m) * (amount / n) * [(n * [n + 1]) / 2],
/// ```
///
/// where `m` is the max number of lockup days and `n` is the number of
/// days for the entire vesting schedule.
///
/// ### Decay
///
/// To calculate the decay, we can simply re-use the above sum, adjusting
/// `n` for the number of days left in the lockup.
///
/// ## Voting Power Warmup
///
/// To prevent the case where one borrows tokens to suddenly vote on a
/// favorable proposal, one can introduce a "warmup" period, where the
/// lockup calculation doesn't start until a specific date, so that
/// the voting power of all new depositors remains zero for an initial
/// period of time, say, two weeks.
pub fn voting_power(&self) -> Result<u64> {
let curr_ts = Clock::get()?.unix_timestamp;
// Voting power is zero until the warmup period ends.
if curr_ts < self.lockup.start_ts {
return Ok(0);
}
match self.lockup.kind {
LockupKind::Daily => self.voting_power_daily(),
LockupKind::Cliff => self.voting_power_cliff(),
}
}
fn voting_power_daily(&self) -> Result<u64> {
let m = MAX_DAYS_LOCKED;
let n = self.lockup.days_left()?;
let decayed_vote_weight = self
.amount_scaled
.checked_mul(n.checked_mul(n.checked_add(1).unwrap()).unwrap())
.unwrap()
.checked_div(m.checked_mul(n).unwrap().checked_mul(2).unwrap())
.unwrap();
Ok(decayed_vote_weight)
}
fn voting_power_cliff(&self) -> Result<u64> {
let voting_weight = self
.lockup
.days_left()?
.checked_mul(self.amount_scaled)
.unwrap()
.checked_div(MAX_DAYS_LOCKED)
.unwrap();
Ok(voting_weight)
}
/// Returns the amount of unlocked tokens for this deposit--in native units
/// of the original token amount (not scaled by the exchange rate).
pub fn vested(&self) -> Result<u64> {
let curr_ts = Clock::get()?.unix_timestamp;
if curr_ts < self.lockup.start_ts {
return Ok(0);
}
match self.lockup.kind {
LockupKind::Daily => self.vested_daily(),
LockupKind::Cliff => self.vested_cliff(),
}
}
fn vested_daily(&self) -> Result<u64> {
let day_current = self.lockup.day_current()?;
let days_total = self.lockup.days_total()?;
if day_current >= days_total {
return Ok(self.amount_deposited);
}
let vested = self
.amount_deposited
.checked_mul(day_current)
.unwrap()
.checked_div(days_total)
.unwrap();
Ok(vested)
}
fn vested_cliff(&self) -> Result<u64> {
let curr_ts = Clock::get()?.unix_timestamp;
if curr_ts < self.lockup.end_ts {
return Ok(0);
}
Ok(self.amount_deposited)
}
/// Returns the amount left in the deposit, ignoring the vesting schedule.
pub fn amount_left(&self) -> u64 {
self.amount_deposited
.checked_sub(self.amount_withdrawn)
.unwrap()
}
}
#[zero_copy]
#[derive(AnchorSerialize, AnchorDeserialize)]
pub struct Lockup {
pub kind: LockupKind,
// Start of the lockup, shifted by the warmup period.
pub start_ts: i64,
// End of the lockup, shifted by the warmup period.
pub end_ts: i64,
// Empty bytes for future upgrades.
pub padding: [u8; 16],
}
impl Lockup {
/// Returns the number of days left on the lockup, ignoring the warmup
/// period.
pub fn days_left(&self) -> Result<u64> {
Ok(self.days_total()?.checked_sub(self.day_current()?).unwrap())
}
/// Returns the current day in the vesting schedule. The warmup period is
/// treated as day zero.
pub fn day_current(&self) -> Result<u64> {
let curr_ts = Clock::get()?.unix_timestamp;
// Warmup period hasn't ended.
if curr_ts < self.start_ts {
return Ok(0);
}
u64::try_from({
let secs_elapsed = curr_ts.checked_sub(self.start_ts).unwrap();
secs_elapsed.checked_div(SECS_PER_DAY).unwrap()
})
.map_err(|_| ErrorCode::UnableToConvert.into())
}
/// Returns the total amount of days in the lockup period, ignoring the
/// warmup period.
pub fn days_total(&self) -> Result<u64> {
// Number of seconds in the entire lockup.
let lockup_secs = self.end_ts.checked_sub(self.start_ts).unwrap();
require!(lockup_secs % SECS_PER_DAY == 0, InvalidLockupPeriod);
// Total days in the entire lockup.
let lockup_days = u64::try_from(lockup_secs.checked_div(SECS_PER_DAY).unwrap()).unwrap();
Ok(lockup_days)
}
}
#[repr(u8)]
#[derive(AnchorSerialize, AnchorDeserialize, Debug, Clone, Copy)]
pub enum LockupKind {
Daily,
Cliff,
}