Contract Name:
Vyper_contract
Contract Source Code:
File 1 of 1 : Vyper_contract
# @version 0.2.16
"""
@title Angle Fee Distribution
@author Angle Protocol
@license MIT
"""
# Original idea and credit:
# Curve Finance's FeeDistributor
# https://github.com/curvefi/curve-dao-contracts/blob/master/contracts/FeeDistributor.vy
from vyper.interfaces import ERC20
interface VotingEscrow:
def user_point_epoch(addr: address) -> uint256: view
def epoch() -> uint256: view
def user_point_history(addr: address, loc: uint256) -> Point: view
def point_history(loc: uint256) -> Point: view
def checkpoint(): nonpayable
event CommitAdmin:
admin: address
event ApplyAdmin:
admin: address
event ToggleAllowCheckpointToken:
toggle_flag: bool
event CheckpointToken:
time: uint256
tokens: uint256
event Claimed:
recipient: indexed(address)
amount: uint256
claim_epoch: uint256
max_epoch: uint256
struct Point:
bias: int128
slope: int128 # - dweight / dt
ts: uint256
blk: uint256 # block
WEEK: constant(uint256) = 7 * 86400
TOKEN_CHECKPOINT_DEADLINE: constant(uint256) = 86400
start_time: public(uint256)
time_cursor: public(uint256)
time_cursor_of: public(HashMap[address, uint256])
user_epoch_of: public(HashMap[address, uint256])
last_token_time: public(uint256)
tokens_per_week: public(uint256[1000000000000000])
voting_escrow: public(address)
token: public(address)
total_received: public(uint256)
token_last_balance: public(uint256)
ve_supply: public(uint256[1000000000000000]) # VE total supply at week bounds
admin: public(address)
future_admin: public(address)
can_checkpoint_token: public(bool)
emergency_return: public(address)
is_killed: public(bool)
@external
def __init__(
_voting_escrow: address,
_start_time: uint256,
_token: address,
_admin: address,
_emergency_return: address
):
"""
@notice Contract constructor
@param _voting_escrow VotingEscrow contract address
@param _start_time Epoch time for fee distribution to start
@param _token Fee token address
@param _admin Admin address
@param _emergency_return Address to transfer `_token` balance to
if this contract is killed
"""
assert _voting_escrow != ZERO_ADDRESS
assert _token != ZERO_ADDRESS
assert _admin != ZERO_ADDRESS
assert _emergency_return != ZERO_ADDRESS
t: uint256 = _start_time / WEEK * WEEK
self.start_time = t
self.last_token_time = t
self.time_cursor = t
self.token = _token
self.voting_escrow = _voting_escrow
self.admin = _admin
self.emergency_return = _emergency_return
@internal
def _checkpoint_token():
token_balance: uint256 = ERC20(self.token).balanceOf(self)
to_distribute: uint256 = token_balance - self.token_last_balance
self.token_last_balance = token_balance
t: uint256 = self.last_token_time
since_last: uint256 = block.timestamp - t
self.last_token_time = block.timestamp
this_week: uint256 = t / WEEK * WEEK
next_week: uint256 = 0
for i in range(20):
next_week = this_week + WEEK
if block.timestamp < next_week:
if since_last == 0 and block.timestamp == t:
self.tokens_per_week[this_week] += to_distribute
else:
self.tokens_per_week[this_week] += to_distribute * (block.timestamp - t) / since_last
break
else:
if since_last == 0 and next_week == t:
self.tokens_per_week[this_week] += to_distribute
else:
self.tokens_per_week[this_week] += to_distribute * (next_week - t) / since_last
t = next_week
this_week = next_week
log CheckpointToken(block.timestamp, to_distribute)
@external
def checkpoint_token():
"""
@notice Update the token checkpoint
@dev Calculates the total number of tokens to be distributed in a given week.
During setup for the initial distribution this function is only callable
by the contract owner. Beyond initial distro, it can be enabled for anyone
to call.
"""
assert (msg.sender == self.admin) or\
(self.can_checkpoint_token and (block.timestamp > self.last_token_time + TOKEN_CHECKPOINT_DEADLINE))
self._checkpoint_token()
@internal
def _find_timestamp_epoch(ve: address, _timestamp: uint256) -> uint256:
_min: uint256 = 0
_max: uint256 = VotingEscrow(ve).epoch()
for i in range(128):
if _min >= _max:
break
_mid: uint256 = (_min + _max + 2) / 2
pt: Point = VotingEscrow(ve).point_history(_mid)
if pt.ts <= _timestamp:
_min = _mid
else:
_max = _mid - 1
return _min
@view
@internal
def _find_timestamp_user_epoch(ve: address, user: address, _timestamp: uint256, max_user_epoch: uint256) -> uint256:
_min: uint256 = 0
_max: uint256 = max_user_epoch
for i in range(128):
if _min >= _max:
break
_mid: uint256 = (_min + _max + 2) / 2
pt: Point = VotingEscrow(ve).user_point_history(user, _mid)
if pt.ts <= _timestamp:
_min = _mid
else:
_max = _mid - 1
return _min
@view
@external
def ve_for_at(_user: address, _timestamp: uint256) -> uint256:
"""
@notice Get the veANGLE balance for `_user` at `_timestamp`
@param _user Address to query balance for
@param _timestamp Epoch time
@return uint256 veANGLE balance
"""
ve: address = self.voting_escrow
max_user_epoch: uint256 = VotingEscrow(ve).user_point_epoch(_user)
epoch: uint256 = self._find_timestamp_user_epoch(ve, _user, _timestamp, max_user_epoch)
pt: Point = VotingEscrow(ve).user_point_history(_user, epoch)
return convert(max(pt.bias - pt.slope * convert(_timestamp - pt.ts, int128), empty(int128)), uint256)
@internal
def _checkpoint_total_supply():
ve: address = self.voting_escrow
t: uint256 = self.time_cursor
rounded_timestamp: uint256 = block.timestamp / WEEK * WEEK
VotingEscrow(ve).checkpoint()
for i in range(20):
if t > rounded_timestamp:
break
else:
epoch: uint256 = self._find_timestamp_epoch(ve, t)
pt: Point = VotingEscrow(ve).point_history(epoch)
dt: int128 = 0
if t > pt.ts:
# If the point is at 0 epoch, it can actually be earlier than the first deposit
# Then make dt 0
dt = convert(t - pt.ts, int128)
self.ve_supply[t] = convert(max(pt.bias - pt.slope * dt, empty(int128)), uint256)
t += WEEK
self.time_cursor = t
@external
def checkpoint_total_supply():
"""
@notice Update the veANGLE total supply checkpoint
@dev The checkpoint is also updated by the first claimant each
new epoch week. This function may be called independently
of a claim, to reduce claiming gas costs.
"""
self._checkpoint_total_supply()
@internal
def _claim(addr: address, ve: address, _last_token_time: uint256) -> uint256:
# Minimal user_epoch is 0 (if user had no point)
user_epoch: uint256 = 0
to_distribute: uint256 = 0
max_user_epoch: uint256 = VotingEscrow(ve).user_point_epoch(addr)
_start_time: uint256 = self.start_time
if max_user_epoch == 0:
# No lock = no fees
return 0
week_cursor: uint256 = self.time_cursor_of[addr]
if week_cursor == 0:
# Need to do the initial binary search
user_epoch = self._find_timestamp_user_epoch(ve, addr, _start_time, max_user_epoch)
else:
user_epoch = self.user_epoch_of[addr]
if user_epoch == 0:
user_epoch = 1
user_point: Point = VotingEscrow(ve).user_point_history(addr, user_epoch)
if week_cursor == 0:
week_cursor = (user_point.ts + WEEK - 1) / WEEK * WEEK
if week_cursor >= _last_token_time:
return 0
if week_cursor < _start_time:
week_cursor = _start_time
old_user_point: Point = empty(Point)
# Iterate over weeks
for i in range(50):
if week_cursor >= _last_token_time:
break
if week_cursor >= user_point.ts and user_epoch <= max_user_epoch:
user_epoch += 1
old_user_point = user_point
if user_epoch > max_user_epoch:
user_point = empty(Point)
else:
user_point = VotingEscrow(ve).user_point_history(addr, user_epoch)
else:
# Calc
# + i * 2 is for rounding errors
dt: int128 = convert(week_cursor - old_user_point.ts, int128)
balance_of: uint256 = convert(max(old_user_point.bias - dt * old_user_point.slope, empty(int128)), uint256)
if balance_of == 0 and user_epoch > max_user_epoch:
break
if balance_of > 0:
to_distribute += balance_of * self.tokens_per_week[week_cursor] / self.ve_supply[week_cursor]
week_cursor += WEEK
user_epoch = min(max_user_epoch, user_epoch - 1)
self.user_epoch_of[addr] = user_epoch
self.time_cursor_of[addr] = week_cursor
log Claimed(addr, to_distribute, user_epoch, max_user_epoch)
return to_distribute
@external
@nonreentrant('lock')
def claim(_addr: address = msg.sender) -> uint256:
"""
@notice Claim fees for `_addr`
@dev Each call to claim look at a maximum of 50 user veANGLE points.
For accounts with many veANGLE related actions, this function
may need to be called more than once to claim all available
fees. In the `Claimed` event that fires, if `claim_epoch` is
less than `max_epoch`, the account may claim again.
@param _addr Address to claim fees for
@return uint256 Amount of fees claimed in the call
"""
assert not self.is_killed
if block.timestamp >= self.time_cursor:
self._checkpoint_total_supply()
last_token_time: uint256 = self.last_token_time
if self.can_checkpoint_token and (block.timestamp > last_token_time + TOKEN_CHECKPOINT_DEADLINE):
self._checkpoint_token()
last_token_time = block.timestamp
last_token_time = last_token_time / WEEK * WEEK
amount: uint256 = self._claim(_addr, self.voting_escrow, last_token_time)
if amount != 0:
token: address = self.token
assert ERC20(token).transfer(_addr, amount)
self.token_last_balance -= amount
return amount
@external
@nonreentrant('lock')
def claim_many(_receivers: address[20]) -> bool:
"""
@notice Make multiple fee claims in a single call
@dev Used to claim for many accounts at once, or to make
multiple claims for the same address when that address
has significant veANGLE history
@param _receivers List of addresses to claim for. Claiming
terminates at the first `ZERO_ADDRESS`.
@return bool success
"""
assert not self.is_killed
if block.timestamp >= self.time_cursor:
self._checkpoint_total_supply()
last_token_time: uint256 = self.last_token_time
if self.can_checkpoint_token and (block.timestamp > last_token_time + TOKEN_CHECKPOINT_DEADLINE):
self._checkpoint_token()
last_token_time = block.timestamp
last_token_time = last_token_time / WEEK * WEEK
voting_escrow: address = self.voting_escrow
token: address = self.token
total: uint256 = 0
for addr in _receivers:
if addr == ZERO_ADDRESS:
break
amount: uint256 = self._claim(addr, voting_escrow, last_token_time)
if amount != 0:
assert ERC20(token).transfer(addr, amount)
total += amount
if total != 0:
self.token_last_balance -= total
return True
@external
def burn(_coin: address) -> bool:
"""
@notice Receive _coin into the contract and trigger a token checkpoint
@param _coin Address of the coin being received (must be in the whitelisted tokens)
@return bool success
"""
assert _coin == self.token
assert not self.is_killed
amount: uint256 = ERC20(_coin).balanceOf(msg.sender)
if amount != 0:
ERC20(_coin).transferFrom(msg.sender, self, amount)
if self.can_checkpoint_token and (block.timestamp > self.last_token_time + TOKEN_CHECKPOINT_DEADLINE):
self._checkpoint_token()
return True
@external
def commit_admin(_addr: address):
"""
@notice Commit transfer of ownership
@param _addr New admin address
"""
assert msg.sender == self.admin # dev: access denied
assert _addr != ZERO_ADDRESS # dev: future admin cannot be the 0 address
self.future_admin = _addr
log CommitAdmin(_addr)
@external
def accept_admin():
"""
@notice Accept a pending ownership transfer
"""
_admin: address = self.future_admin
assert msg.sender == _admin # dev: future admin only
self.admin = _admin
log ApplyAdmin(_admin)
@external
def toggle_allow_checkpoint_token():
"""
@notice Toggle permission for checkpointing by any account
"""
assert msg.sender == self.admin
flag: bool = not self.can_checkpoint_token
self.can_checkpoint_token = flag
log ToggleAllowCheckpointToken(flag)
@external
def kill_me():
"""
@notice Kill the contract
@dev Killing transfers the entire tokens balance to the emergency return address
and blocks the ability to claim or burn. The contract cannot be unkilled.
"""
assert msg.sender == self.admin
self.is_killed = True
token: address = self.token
assert ERC20(token).transfer(self.emergency_return, ERC20(token).balanceOf(self))
@external
def recover_balance(_coin: address) -> bool:
"""
@notice Recover ERC20 tokens from this contract
@dev Tokens are sent to the emergency return address.
@param _coin Token address
@return bool success
"""
assert msg.sender == self.admin
assert _coin != self.token
amount: uint256 = ERC20(_coin).balanceOf(self)
response: Bytes[32] = raw_call(
_coin,
concat(
method_id("transfer(address,uint256)"),
convert(self.emergency_return, bytes32),
convert(amount, bytes32),
),
max_outsize=32,
)
if len(response) != 0:
assert convert(response, bool)
return True