Agents

is_killed: bool
kill_deadline: uint256
KILL_DEADLINE_DT: constant(uint256) = 2 * 30 * 86400

@external
def kill_me():
    assert msg.sender == self.owner  # dev: only owner
    assert self.kill_deadline > block.timestamp  # dev: deadline has passed
    self.is_killed = True

@external
def unkill_me():
    assert msg.sender == self.owner  # dev: only owner
    self.is_killed = False    

is_killed: public(bool)

@external
def set_killed(_is_killed: bool):
    """
    @notice Set the killed status for this contract
    @dev When killed, the gauge always yields a rate of 0 and so cannot mint CRV
    @param _is_killed Killed status to set
    """
    assert msg.sender == self.admin

    self.is_killed = _is_killed

@internal
def _checkpoint(addr: address):
    """
    @notice Checkpoint for a user
    @param addr User address
    """
    _period: int128 = self.period
    _period_time: uint256 = self.period_timestamp[_period]
    _integrate_inv_supply: uint256 = self.integrate_inv_supply[_period]
    rate: uint256 = self.inflation_rate
    new_rate: uint256 = rate
    prev_future_epoch: uint256 = self.future_epoch_time
    if prev_future_epoch >= _period_time:
        self.future_epoch_time = CRV20(CRV).future_epoch_time_write()
        new_rate = CRV20(CRV).rate()
        self.inflation_rate = new_rate

    if self.is_killed:
        # Stop distributing inflation as soon as killed
        rate = 0

    # Update integral of 1/supply
    if block.timestamp > _period_time:
        _working_supply: uint256 = self.working_supply
        Controller(GAUGE_CONTROLLER).checkpoint_gauge(self)
        prev_week_time: uint256 = _period_time
        week_time: uint256 = min((_period_time + WEEK) / WEEK * WEEK, block.timestamp)

        for i in range(500):
            dt: uint256 = week_time - prev_week_time
            w: uint256 = Controller(GAUGE_CONTROLLER).gauge_relative_weight(self, prev_week_time / WEEK * WEEK)

            if _working_supply > 0:
                if prev_future_epoch >= prev_week_time and prev_future_epoch < week_time:
                    # If we went across one or multiple epochs, apply the rate
                    # of the first epoch until it ends, and then the rate of
                    # the last epoch.
                    # If more than one epoch is crossed - the gauge gets less,
                    # but that'd meen it wasn't called for more than 1 year
                    _integrate_inv_supply += rate * w * (prev_future_epoch - prev_week_time) / _working_supply
                    rate = new_rate
                    _integrate_inv_supply += rate * w * (week_time - prev_future_epoch) / _working_supply
                else:
                    _integrate_inv_supply += rate * w * dt / _working_supply
                # On precisions of the calculation
                # rate ~= 10e18
                # last_weight > 0.01 * 1e18 = 1e16 (if pool weight is 1%)
                # _working_supply ~= TVL * 1e18 ~= 1e26 ($100M for example)
                # The largest loss is at dt = 1
                # Loss is 1e-9 - acceptable

            if week_time == block.timestamp:
                break
            prev_week_time = week_time
            week_time = min(week_time + WEEK, block.timestamp)

    _period += 1
    self.period = _period
    self.period_timestamp[_period] = block.timestamp
    self.integrate_inv_supply[_period] = _integrate_inv_supply

    # Update user-specific integrals
    _working_balance: uint256 = self.working_balances[addr]
    self.integrate_fraction[addr] += _working_balance * (_integrate_inv_supply - self.integrate_inv_supply_of[addr]) / 10 ** 18
    self.integrate_inv_supply_of[addr] = _integrate_inv_supply
    self.integrate_checkpoint_of[addr] = block.timestamp