Contract Name:
CurveTwocryptoSwap
Contract Source Code:
File 1 of 1 : CurveTwocryptoSwap
# pragma version 0.3.10
# pragma optimize gas
# pragma evm-version paris
"""
@title CurveTwocryptoSwap
@custom:version 2.1.0
@author Curve.Fi
@license Copyright (c) Curve.Fi, 2023 - all rights reserved
@notice A Curve AMM pool for 2 unpegged assets (e.g. WETH, USD).
@dev All prices in the AMM are with respect to the first token in the pool.
"""
from vyper.interfaces import ERC20
implements: ERC20 # <--------------------- AMM contract is also the LP token.
# ------------------------------- Version ------------------------------------
version: public(constant(String[8])) = "2.1.0"
# --------------------------------- Interfaces -------------------------------
interface Math:
def wad_exp(_power: int256) -> uint256: view
def newton_D(
ANN: uint256,
gamma: uint256,
x_unsorted: uint256[N_COINS],
K0_prev: uint256
) -> uint256: view
def get_y(
ANN: uint256,
gamma: uint256,
x: uint256[N_COINS],
D: uint256,
i: uint256,
) -> uint256[2]: view
def get_p(
_xp: uint256[N_COINS],
_D: uint256,
_A_gamma: uint256[2],
) -> uint256: view
interface Factory:
def admin() -> address: view
def fee_receiver() -> address: view
def views_implementation() -> address: view
interface Views:
def calc_token_amount(
amounts: uint256[N_COINS], deposit: bool, swap: address
) -> uint256: view
def get_dy(
i: uint256, j: uint256, dx: uint256, swap: address
) -> uint256: view
def get_dx(
i: uint256, j: uint256, dy: uint256, swap: address
) -> uint256: view
# ------------------------------- Events -------------------------------------
event Transfer:
sender: indexed(address)
receiver: indexed(address)
value: uint256
event Approval:
owner: indexed(address)
spender: indexed(address)
value: uint256
event TokenExchange:
buyer: indexed(address)
sold_id: uint256
tokens_sold: uint256
bought_id: uint256
tokens_bought: uint256
fee: uint256
packed_price_scale: uint256
event AddLiquidity:
provider: indexed(address)
token_amounts: uint256[N_COINS]
fee: uint256
token_supply: uint256
packed_price_scale: uint256
event RemoveLiquidity:
provider: indexed(address)
token_amounts: uint256[N_COINS]
token_supply: uint256
event RemoveLiquidityOne:
provider: indexed(address)
token_amount: uint256
coin_index: uint256
coin_amount: uint256
approx_fee: uint256
packed_price_scale: uint256
event NewParameters:
mid_fee: uint256
out_fee: uint256
fee_gamma: uint256
allowed_extra_profit: uint256
adjustment_step: uint256
ma_time: uint256
event RampAgamma:
initial_A: uint256
future_A: uint256
initial_gamma: uint256
future_gamma: uint256
initial_time: uint256
future_time: uint256
event StopRampA:
current_A: uint256
current_gamma: uint256
time: uint256
event ClaimAdminFee:
admin: indexed(address)
tokens: uint256[N_COINS]
# ----------------------- Storage/State Variables ----------------------------
N_COINS: constant(uint256) = 2
PRECISION: constant(uint256) = 10**18 # <------- The precision to convert to.
PRECISIONS: immutable(uint256[N_COINS])
MATH: public(immutable(Math))
coins: public(immutable(address[N_COINS]))
factory: public(immutable(Factory))
cached_price_scale: uint256 # <------------------------ Internal price scale.
cached_price_oracle: uint256 # <------- Price target given by moving average.
last_prices: public(uint256)
last_timestamp: public(uint256) # idx 0 is for prices, idx 1 is for xcp.
initial_A_gamma: public(uint256)
initial_A_gamma_time: public(uint256)
future_A_gamma: public(uint256)
future_A_gamma_time: public(uint256) # <------ Time when ramping is finished.
# This value is 0 (default) when pool is first deployed, and only gets
# populated by block.timestamp + future_time in `ramp_A_gamma` when the
# ramping process is initiated. After ramping is finished
# (i.e. self.future_A_gamma_time < block.timestamp), the variable is left
# and not set to 0.
balances: public(uint256[N_COINS])
D: public(uint256)
xcp_profit: public(uint256)
xcp_profit_a: public(uint256) # <--- Full profit at last claim of admin fees.
virtual_price: public(uint256) # <------ Cached (fast to read) virtual price.
# The cached `virtual_price` is also used internally.
# Params that affect how price_scale get adjusted :
packed_rebalancing_params: public(uint256) # <---------- Contains rebalancing
# parameters allowed_extra_profit, adjustment_step, and ma_time.
# Fee params that determine dynamic fees:
packed_fee_params: public(uint256) # <---- Packs mid_fee, out_fee, fee_gamma.
ADMIN_FEE: public(constant(uint256)) = 5 * 10**9 # <----- 50% of earned fees.
MIN_FEE: constant(uint256) = 5 * 10**5 # <-------------------------- 0.5 BPS.
MAX_FEE: constant(uint256) = 10 * 10**9
NOISE_FEE: constant(uint256) = 10**5 # <---------------------------- 0.1 BPS.
# ----------------------- Admin params ---------------------------------------
last_admin_fee_claim_timestamp: uint256
admin_lp_virtual_balance: uint256
MIN_RAMP_TIME: constant(uint256) = 86400
MIN_ADMIN_FEE_CLAIM_INTERVAL: constant(uint256) = 86400
A_MULTIPLIER: constant(uint256) = 10000
MIN_A: constant(uint256) = N_COINS**N_COINS * A_MULTIPLIER / 10
MAX_A: constant(uint256) = N_COINS**N_COINS * A_MULTIPLIER * 1000
MAX_A_CHANGE: constant(uint256) = 10
MIN_GAMMA: constant(uint256) = 10**10
MAX_GAMMA: constant(uint256) = 199 * 10**15 # 1.99 * 10**17
# ----------------------- ERC20 Specific vars --------------------------------
name: public(immutable(String[64]))
symbol: public(immutable(String[32]))
decimals: public(constant(uint8)) = 18
balanceOf: public(HashMap[address, uint256])
allowance: public(HashMap[address, HashMap[address, uint256]])
totalSupply: public(uint256)
nonces: public(HashMap[address, uint256])
EIP712_TYPEHASH: constant(bytes32) = keccak256(
"EIP712Domain(string name,string version,uint256 chainId,address verifyingContract,bytes32 salt)"
)
EIP2612_TYPEHASH: constant(bytes32) = keccak256(
"Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
)
VERSION_HASH: constant(bytes32) = keccak256(version)
NAME_HASH: immutable(bytes32)
CACHED_CHAIN_ID: immutable(uint256)
salt: public(immutable(bytes32))
CACHED_DOMAIN_SEPARATOR: immutable(bytes32)
# ----------------------- Contract -------------------------------------------
@external
def __init__(
_name: String[64],
_symbol: String[32],
_coins: address[N_COINS],
_math: address,
_salt: bytes32,
packed_precisions: uint256,
packed_gamma_A: uint256,
packed_fee_params: uint256,
packed_rebalancing_params: uint256,
initial_price: uint256,
):
MATH = Math(_math)
factory = Factory(msg.sender)
name = _name
symbol = _symbol
coins = _coins
PRECISIONS = self._unpack_2(packed_precisions) # <-- Precisions of coins.
# --------------- Validate A and gamma parameters here and not in factory.
gamma_A: uint256[2] = self._unpack_2(packed_gamma_A) # gamma is at idx 0.
assert gamma_A[0] > MIN_GAMMA-1
assert gamma_A[0] < MAX_GAMMA+1
assert gamma_A[1] > MIN_A-1
assert gamma_A[1] < MAX_A+1
self.initial_A_gamma = packed_gamma_A
self.future_A_gamma = packed_gamma_A
# ------------------------------------------------------------------------
self.packed_rebalancing_params = packed_rebalancing_params # <-- Contains
# rebalancing params: allowed_extra_profit, adjustment_step,
# and ma_exp_time.
self.packed_fee_params = packed_fee_params # <-------------- Contains Fee
# params: mid_fee, out_fee and fee_gamma.
self.cached_price_scale = initial_price
self.cached_price_oracle = initial_price
self.last_prices = initial_price
self.last_timestamp = block.timestamp
self.xcp_profit_a = 10**18
# Cache DOMAIN_SEPARATOR. If chain.id is not CACHED_CHAIN_ID, then
# DOMAIN_SEPARATOR will be re-calculated each time `permit` is called.
# Otherwise, it will always use CACHED_DOMAIN_SEPARATOR.
# see: `_domain_separator()` for its implementation.
NAME_HASH = keccak256(name)
salt = _salt
CACHED_CHAIN_ID = chain.id
CACHED_DOMAIN_SEPARATOR = keccak256(
_abi_encode(
EIP712_TYPEHASH,
NAME_HASH,
VERSION_HASH,
chain.id,
self,
salt,
)
)
log Transfer(empty(address), self, 0) # <------- Fire empty transfer from
# 0x0 to self for indexers to catch.
# ------------------- Token transfers in and out of the AMM ------------------
@internal
def _transfer_in(
_coin_idx: uint256,
_dx: uint256,
sender: address,
expect_optimistic_transfer: bool,
) -> uint256:
"""
@notice Transfers `_coin` from `sender` to `self` and calls `callback_sig`
if it is not empty.
@params _coin_idx uint256 Index of the coin to transfer in.
@params dx amount of `_coin` to transfer into the pool.
@params sender address to transfer `_coin` from.
@params expect_optimistic_transfer bool True if pool expects user to transfer.
This is only enabled for exchange_received.
@return The amount of tokens received.
"""
coin_balance: uint256 = ERC20(coins[_coin_idx]).balanceOf(self)
if expect_optimistic_transfer: # Only enabled in exchange_received:
# it expects the caller of exchange_received to have sent tokens to
# the pool before calling this method.
# If someone donates extra tokens to the contract: do not acknowledge.
# We only want to know if there are dx amount of tokens. Anything extra,
# we ignore. This is why we need to check if received_amounts (which
# accounts for coin balances of the contract) is atleast dx.
# If we checked for received_amounts == dx, an extra transfer without a
# call to exchange_received will break the method.
dx: uint256 = coin_balance - self.balances[_coin_idx]
assert dx >= _dx # dev: user didn't give us coins
# Adjust balances
self.balances[_coin_idx] += dx
return dx
# ----------------------------------------------- ERC20 transferFrom flow.
# EXTERNAL CALL
assert ERC20(coins[_coin_idx]).transferFrom(
sender,
self,
_dx,
default_return_value=True
)
dx: uint256 = ERC20(coins[_coin_idx]).balanceOf(self) - coin_balance
self.balances[_coin_idx] += dx
return dx
@internal
def _transfer_out(_coin_idx: uint256, _amount: uint256, receiver: address):
"""
@notice Transfer a single token from the pool to receiver.
@dev This function is called by `remove_liquidity` and
`remove_liquidity_one`, `_claim_admin_fees` and `_exchange` methods.
@params _coin_idx uint256 Index of the token to transfer out
@params _amount Amount of token to transfer out
@params receiver Address to send the tokens to
"""
# Adjust balances before handling transfers:
self.balances[_coin_idx] -= _amount
# EXTERNAL CALL
assert ERC20(coins[_coin_idx]).transfer(
receiver,
_amount,
default_return_value=True
)
# -------------------------- AMM Main Functions ------------------------------
@external
@nonreentrant("lock")
def exchange(
i: uint256,
j: uint256,
dx: uint256,
min_dy: uint256,
receiver: address = msg.sender
) -> uint256:
"""
@notice Exchange using wrapped native token by default
@param i Index value for the input coin
@param j Index value for the output coin
@param dx Amount of input coin being swapped in
@param min_dy Minimum amount of output coin to receive
@param receiver Address to send the output coin to. Default is msg.sender
@return uint256 Amount of tokens at index j received by the `receiver
"""
# _transfer_in updates self.balances here:
dx_received: uint256 = self._transfer_in(
i,
dx,
msg.sender,
False
)
# No ERC20 token transfers occur here:
out: uint256[3] = self._exchange(
i,
j,
dx_received,
min_dy,
)
# _transfer_out updates self.balances here. Update to state occurs before
# external calls:
self._transfer_out(j, out[0], receiver)
# log:
log TokenExchange(msg.sender, i, dx_received, j, out[0], out[1], out[2])
return out[0]
@external
@nonreentrant('lock')
def exchange_received(
i: uint256,
j: uint256,
dx: uint256,
min_dy: uint256,
receiver: address = msg.sender,
) -> uint256:
"""
@notice Exchange: but user must transfer dx amount of coin[i] tokens to pool first.
Pool will not call transferFrom and will only check if a surplus of
coins[i] is greater than or equal to `dx`.
@dev Use-case is to reduce the number of redundant ERC20 token
transfers in zaps. Primarily for dex-aggregators/arbitrageurs/searchers.
Note for users: please transfer + exchange_received in 1 tx.
@param i Index value for the input coin
@param j Index value for the output coin
@param dx Amount of input coin being swapped in
@param min_dy Minimum amount of output coin to receive
@param receiver Address to send the output coin to
@return uint256 Amount of tokens at index j received by the `receiver`
"""
# _transfer_in updates self.balances here:
dx_received: uint256 = self._transfer_in(
i,
dx,
msg.sender,
True # <---- expect_optimistic_transfer is set to True here.
)
# No ERC20 token transfers occur here:
out: uint256[3] = self._exchange(
i,
j,
dx_received,
min_dy,
)
# _transfer_out updates self.balances here. Update to state occurs before
# external calls:
self._transfer_out(j, out[0], receiver)
# log:
log TokenExchange(msg.sender, i, dx_received, j, out[0], out[1], out[2])
return out[0]
@external
@nonreentrant("lock")
def add_liquidity(
amounts: uint256[N_COINS],
min_mint_amount: uint256,
receiver: address = msg.sender
) -> uint256:
"""
@notice Adds liquidity into the pool.
@param amounts Amounts of each coin to add.
@param min_mint_amount Minimum amount of LP to mint.
@param receiver Address to send the LP tokens to. Default is msg.sender
@return uint256 Amount of LP tokens received by the `receiver
"""
A_gamma: uint256[2] = self._A_gamma()
xp: uint256[N_COINS] = self.balances
amountsp: uint256[N_COINS] = empty(uint256[N_COINS])
d_token: uint256 = 0
d_token_fee: uint256 = 0
old_D: uint256 = 0
assert amounts[0] + amounts[1] > 0 # dev: no coins to add
# --------------------- Get prices, balances -----------------------------
price_scale: uint256 = self.cached_price_scale
# -------------------------------------- Update balances and calculate xp.
xp_old: uint256[N_COINS] = xp
amounts_received: uint256[N_COINS] = empty(uint256[N_COINS])
########################## TRANSFER IN <-------
for i in range(N_COINS):
if amounts[i] > 0:
# Updates self.balances here:
amounts_received[i] = self._transfer_in(
i,
amounts[i],
msg.sender,
False, # <--------------------- Disable optimistic transfers.
)
xp[i] = xp[i] + amounts_received[i]
xp = [
xp[0] * PRECISIONS[0],
unsafe_div(xp[1] * price_scale * PRECISIONS[1], PRECISION)
]
xp_old = [
xp_old[0] * PRECISIONS[0],
unsafe_div(xp_old[1] * price_scale * PRECISIONS[1], PRECISION)
]
for i in range(N_COINS):
if amounts_received[i] > 0:
amountsp[i] = xp[i] - xp_old[i]
# -------------------- Calculate LP tokens to mint -----------------------
if self.future_A_gamma_time > block.timestamp: # <--- A_gamma is ramping.
# ----- Recalculate the invariant if A or gamma are undergoing a ramp.
old_D = MATH.newton_D(A_gamma[0], A_gamma[1], xp_old, 0)
else:
old_D = self.D
D: uint256 = MATH.newton_D(A_gamma[0], A_gamma[1], xp, 0)
token_supply: uint256 = self.totalSupply
if old_D > 0:
d_token = token_supply * D / old_D - token_supply
else:
d_token = self.get_xcp(D, price_scale) # <----- Making initial virtual price equal to 1.
assert d_token > 0 # dev: nothing minted
if old_D > 0:
d_token_fee = (
self._calc_token_fee(amountsp, xp) * d_token / 10**10 + 1
)
d_token -= d_token_fee
token_supply += d_token
self.mint(receiver, d_token)
self.admin_lp_virtual_balance += unsafe_div(ADMIN_FEE * d_token_fee, 10**10)
price_scale = self.tweak_price(A_gamma, xp, D, 0)
else:
# (re)instatiating an empty pool:
self.D = D
self.virtual_price = 10**18
self.xcp_profit = 10**18
self.xcp_profit_a = 10**18
self.mint(receiver, d_token)
assert d_token >= min_mint_amount, "Slippage"
# ---------------------------------------------- Log and claim admin fees.
log AddLiquidity(
receiver,
amounts_received,
d_token_fee,
token_supply,
price_scale
)
return d_token
@external
@nonreentrant("lock")
def remove_liquidity(
_amount: uint256,
min_amounts: uint256[N_COINS],
receiver: address = msg.sender,
) -> uint256[N_COINS]:
"""
@notice This withdrawal method is very safe, does no complex math since
tokens are withdrawn in balanced proportions. No fees are charged.
@param _amount Amount of LP tokens to burn
@param min_amounts Minimum amounts of tokens to withdraw
@param receiver Address to send the withdrawn tokens to
@return uint256[3] Amount of pool tokens received by the `receiver`
"""
amount: uint256 = _amount
balances: uint256[N_COINS] = self.balances
withdraw_amounts: uint256[N_COINS] = empty(uint256[N_COINS])
# -------------------------------------------------------- Burn LP tokens.
total_supply: uint256 = self.totalSupply # <------ Get totalSupply before
self.burnFrom(msg.sender, _amount) # ---- reducing it with self.burnFrom.
# There are two cases for withdrawing tokens from the pool.
# Case 1. Withdrawal does not empty the pool.
# In this situation, D is adjusted proportional to the amount of
# LP tokens burnt. ERC20 tokens transferred is proportional
# to : (AMM balance * LP tokens in) / LP token total supply
# Case 2. Withdrawal empties the pool.
# In this situation, all tokens are withdrawn and the invariant
# is reset.
if amount == total_supply: # <----------------------------------- Case 2.
for i in range(N_COINS):
withdraw_amounts[i] = balances[i]
else: # <-------------------------------------------------------- Case 1.
amount -= 1 # <---- To prevent rounding errors, favor LPs a tiny bit.
for i in range(N_COINS):
withdraw_amounts[i] = balances[i] * amount / total_supply
assert withdraw_amounts[i] >= min_amounts[i]
D: uint256 = self.D
self.D = D - unsafe_div(D * amount, total_supply) # <----------- Reduce D
# proportional to the amount of tokens leaving. Since withdrawals are
# balanced, this is a simple subtraction. If amount == total_supply,
# D will be 0.
# ---------------------------------- Transfers ---------------------------
for i in range(N_COINS):
# _transfer_out updates self.balances here. Update to state occurs
# before external calls:
self._transfer_out(i, withdraw_amounts[i], receiver)
log RemoveLiquidity(msg.sender, withdraw_amounts, total_supply - _amount)
return withdraw_amounts
@external
@nonreentrant("lock")
def remove_liquidity_one_coin(
token_amount: uint256,
i: uint256,
min_amount: uint256,
receiver: address = msg.sender
) -> uint256:
"""
@notice Withdraw liquidity in a single token.
Involves fees (lower than swap fees).
@dev This operation also involves an admin fee claim.
@param token_amount Amount of LP tokens to burn
@param i Index of the token to withdraw
@param min_amount Minimum amount of token to withdraw.
@param receiver Address to send the withdrawn tokens to
@return Amount of tokens at index i received by the `receiver`
"""
self._claim_admin_fees() # <--------- Auto-claim admin fees occasionally.
A_gamma: uint256[2] = self._A_gamma()
dy: uint256 = 0
D: uint256 = 0
p: uint256 = 0
xp: uint256[N_COINS] = empty(uint256[N_COINS])
approx_fee: uint256 = 0
# ------------------------------------------------------------------------
dy, D, xp, approx_fee = self._calc_withdraw_one_coin(
A_gamma,
token_amount,
i,
(self.future_A_gamma_time > block.timestamp), # <------- During ramps
) # we need to update D.
assert dy >= min_amount, "Slippage"
# ---------------------------- State Updates -----------------------------
# Burn user's tokens:
self.burnFrom(msg.sender, token_amount)
packed_price_scale: uint256 = self.tweak_price(A_gamma, xp, D, 0)
# Safe to use D from _calc_withdraw_one_coin here ---^
# ------------------------- Transfers ------------------------------------
# _transfer_out updates self.balances here. Update to state occurs before
# external calls:
self._transfer_out(i, dy, receiver)
log RemoveLiquidityOne(
msg.sender, token_amount, i, dy, approx_fee, packed_price_scale
)
return dy
# -------------------------- Packing functions -------------------------------
@internal
@pure
def _pack_3(x: uint256[3]) -> uint256:
"""
@notice Packs 3 integers with values <= 10**18 into a uint256
@param x The uint256[3] to pack
@return uint256 Integer with packed values
"""
return (x[0] << 128) | (x[1] << 64) | x[2]
@internal
@pure
def _unpack_3(_packed: uint256) -> uint256[3]:
"""
@notice Unpacks a uint256 into 3 integers (values must be <= 10**18)
@param val The uint256 to unpack
@return uint256[3] A list of length 3 with unpacked integers
"""
return [
(_packed >> 128) & 18446744073709551615,
(_packed >> 64) & 18446744073709551615,
_packed & 18446744073709551615,
]
@pure
@internal
def _pack_2(p1: uint256, p2: uint256) -> uint256:
return p1 | (p2 << 128)
@pure
@internal
def _unpack_2(packed: uint256) -> uint256[2]:
return [packed & (2**128 - 1), packed >> 128]
# ---------------------- AMM Internal Functions -------------------------------
@internal
def _exchange(
i: uint256,
j: uint256,
dx_received: uint256,
min_dy: uint256,
) -> uint256[3]:
assert i != j # dev: coin index out of range
assert dx_received > 0 # dev: do not exchange 0 coins
A_gamma: uint256[2] = self._A_gamma()
xp: uint256[N_COINS] = self.balances
dy: uint256 = 0
y: uint256 = xp[j]
x0: uint256 = xp[i] - dx_received # old xp[i]
price_scale: uint256 = self.cached_price_scale
xp = [
xp[0] * PRECISIONS[0],
unsafe_div(xp[1] * price_scale * PRECISIONS[1], PRECISION)
]
# ----------- Update invariant if A, gamma are undergoing ramps ---------
t: uint256 = self.future_A_gamma_time
if t > block.timestamp:
x0 *= PRECISIONS[i]
if i > 0:
x0 = unsafe_div(x0 * price_scale, PRECISION)
x1: uint256 = xp[i] # <------------------ Back up old value in xp ...
xp[i] = x0 # |
self.D = MATH.newton_D(A_gamma[0], A_gamma[1], xp, 0) # |
xp[i] = x1 # <-------------------------------------- ... and restore.
# ----------------------- Calculate dy and fees --------------------------
D: uint256 = self.D
y_out: uint256[2] = MATH.get_y(A_gamma[0], A_gamma[1], xp, D, j)
dy = xp[j] - y_out[0]
xp[j] -= dy
dy -= 1
if j > 0:
dy = dy * PRECISION / price_scale
dy /= PRECISIONS[j]
fee: uint256 = unsafe_div(self._fee(xp) * dy, 10**10)
dy -= fee # <--------------------- Subtract fee from the outgoing amount.
assert dy >= min_dy, "Slippage"
y -= dy
y *= PRECISIONS[j]
if j > 0:
y = unsafe_div(y * price_scale, PRECISION)
xp[j] = y # <------------------------------------------------- Update xp.
# ------ Tweak price_scale with good initial guess for newton_D ----------
price_scale = self.tweak_price(A_gamma, xp, 0, y_out[1])
return [dy, fee, price_scale]
@internal
def tweak_price(
A_gamma: uint256[2],
_xp: uint256[N_COINS],
new_D: uint256,
K0_prev: uint256 = 0,
) -> uint256:
"""
@notice Updates price_oracle, last_price and conditionally adjusts
price_scale. This is called whenever there is an unbalanced
liquidity operation: _exchange, add_liquidity, or
remove_liquidity_one_coin.
@dev Contains main liquidity rebalancing logic, by tweaking `price_scale`.
@param A_gamma Array of A and gamma parameters.
@param _xp Array of current balances.
@param new_D New D value.
@param K0_prev Initial guess for `newton_D`.
"""
# ---------------------------- Read storage ------------------------------
price_oracle: uint256 = self.cached_price_oracle
last_prices: uint256 = self.last_prices
price_scale: uint256 = self.cached_price_scale
rebalancing_params: uint256[3] = self._unpack_3(self.packed_rebalancing_params)
# Contains: allowed_extra_profit, adjustment_step, ma_time. -----^
total_supply: uint256 = self.totalSupply
old_xcp_profit: uint256 = self.xcp_profit
old_virtual_price: uint256 = self.virtual_price
# ------------------ Update Price Oracle if needed -----------------------
last_timestamp: uint256 = self.last_timestamp
alpha: uint256 = 0
if last_timestamp < block.timestamp: # 0th index is for price_oracle.
# The moving average price oracle is calculated using the last_price
# of the trade at the previous block, and the price oracle logged
# before that trade. This can happen only once per block.
# ------------------ Calculate moving average params -----------------
alpha = MATH.wad_exp(
-convert(
unsafe_div(
unsafe_sub(block.timestamp, last_timestamp) * 10**18,
rebalancing_params[2] # <----------------------- ma_time.
),
int256,
)
)
# ---------------------------------------------- Update price oracles.
# ----------------- We cap state price that goes into the EMA with
# 2 x price_scale.
price_oracle = unsafe_div(
min(last_prices, 2 * price_scale) * (10**18 - alpha) +
price_oracle * alpha, # ^-------- Cap spot price into EMA.
10**18
)
self.cached_price_oracle = price_oracle
self.last_timestamp = block.timestamp
# `price_oracle` is used further on to calculate its vector distance from
# price_scale. This distance is used to calculate the amount of adjustment
# to be done to the price_scale.
# ------------------------------------------------------------------------
# ------------------ If new_D is set to 0, calculate it ------------------
D_unadjusted: uint256 = new_D
if new_D == 0: # <--------------------------- _exchange sets new_D to 0.
D_unadjusted = MATH.newton_D(A_gamma[0], A_gamma[1], _xp, K0_prev)
# ----------------------- Calculate last_prices --------------------------
self.last_prices = unsafe_div(
MATH.get_p(_xp, D_unadjusted, A_gamma) * price_scale,
10**18
)
# ---------- Update profit numbers without price adjustment first --------
xp: uint256[N_COINS] = [
unsafe_div(D_unadjusted, N_COINS),
D_unadjusted * PRECISION / (N_COINS * price_scale) # <------ safediv.
] # with price_scale.
xcp_profit: uint256 = 10**18
virtual_price: uint256 = 10**18
if old_virtual_price > 0:
xcp: uint256 = isqrt(xp[0] * xp[1])
virtual_price = 10**18 * xcp / total_supply
xcp_profit = unsafe_div(
old_xcp_profit * virtual_price,
old_virtual_price
) # <---------------- Safu to do unsafe_div as old_virtual_price > 0.
# If A and gamma are not undergoing ramps (t < block.timestamp),
# ensure new virtual_price is not less than old virtual_price,
# else the pool suffers a loss.
if self.future_A_gamma_time < block.timestamp:
# this usually reverts when withdrawing a very small amount of LP tokens
assert virtual_price > old_virtual_price # dev: virtual price decreased
self.xcp_profit = xcp_profit
# ------------ Rebalance liquidity if there's enough profits to adjust it:
if virtual_price * 2 - 10**18 > xcp_profit + 2 * rebalancing_params[0]:
# allowed_extra_profit --------^
# ------------------- Get adjustment step ----------------------------
# Calculate the vector distance between price_scale and
# price_oracle.
norm: uint256 = unsafe_div(
unsafe_mul(price_oracle, 10**18), price_scale
)
if norm > 10**18:
norm = unsafe_sub(norm, 10**18)
else:
norm = unsafe_sub(10**18, norm)
adjustment_step: uint256 = max(
rebalancing_params[1], unsafe_div(norm, 5)
) # ^------------------------------------- adjustment_step.
if norm > adjustment_step: # <---------- We only adjust prices if the
# vector distance between price_oracle and price_scale is
# large enough. This check ensures that no rebalancing
# occurs if the distance is low i.e. the pool prices are
# pegged to the oracle prices.
# ------------------------------------- Calculate new price scale.
p_new: uint256 = unsafe_div(
price_scale * unsafe_sub(norm, adjustment_step) +
adjustment_step * price_oracle,
norm
) # <---- norm is non-zero and gt adjustment_step; unsafe = safe.
# ---------------- Update stale xp (using price_scale) with p_new.
xp = [
_xp[0],
unsafe_div(_xp[1] * p_new, price_scale)
]
# ------------------------------------------ Update D with new xp.
D: uint256 = MATH.newton_D(A_gamma[0], A_gamma[1], xp, 0)
# ------------------------------------- Convert xp to real prices.
xp = [
unsafe_div(D, N_COINS),
D * PRECISION / (N_COINS * p_new)
]
# ---------- Calculate new virtual_price using new xp and D. Reuse
# `old_virtual_price` (but it has new virtual_price).
old_virtual_price = unsafe_div(
10**18 * isqrt(xp[0] * xp[1]), total_supply
) # <----- unsafe_div because we did safediv before (if vp>1e18)
# ---------------------------- Proceed if we've got enough profit.
if (
old_virtual_price > 10**18 and
2 * old_virtual_price - 10**18 > xcp_profit
):
self.D = D
self.virtual_price = old_virtual_price
self.cached_price_scale = p_new
return p_new
# --------- price_scale was not adjusted. Update the profit counter and D.
self.D = D_unadjusted
self.virtual_price = virtual_price
return price_scale
@internal
def _claim_admin_fees():
"""
@notice Claims admin fees and sends it to fee_receiver set in the factory.
@dev Functionally similar to:
1. Calculating admin's share of fees,
2. minting LP tokens,
3. admin claims underlying tokens via remove_liquidity.
"""
# --------------------- Check if fees can be claimed ---------------------
# Disable fee claiming if:
# 1. If time passed since last fee claim is less than
# MIN_ADMIN_FEE_CLAIM_INTERVAL.
# 2. Pool parameters are being ramped.
last_claim_time: uint256 = self.last_admin_fee_claim_timestamp
if (
unsafe_sub(block.timestamp, last_claim_time) < MIN_ADMIN_FEE_CLAIM_INTERVAL or
self.future_A_gamma_time > block.timestamp
):
return
xcp_profit: uint256 = self.xcp_profit # <---------- Current pool profits.
xcp_profit_a: uint256 = self.xcp_profit_a # <- Profits at previous claim.
current_lp_token_supply: uint256 = self.totalSupply
# Do not claim admin fees if:
# 1. insufficient profits accrued since last claim, and
# 2. there are less than 10**18 (or 1 unit of) lp tokens, else it can lead
# to manipulated virtual prices.
if xcp_profit <= xcp_profit_a or current_lp_token_supply < 10**18:
return
# ---------- Conditions met to claim admin fees: compute state. ----------
A_gamma: uint256[2] = self._A_gamma()
D: uint256 = self.D
vprice: uint256 = self.virtual_price
price_scale: uint256 = self.cached_price_scale
fee_receiver: address = factory.fee_receiver()
balances: uint256[N_COINS] = self.balances
# Admin fees are calculated as follows.
# 1. Calculate accrued profit since last claim. `xcp_profit`
# is the current profits. `xcp_profit_a` is the profits
# at the previous claim.
# 2. Take out admin's share, which is hardcoded at 5 * 10**9.
# (50% => half of 100% => 10**10 / 2 => 5 * 10**9).
# 3. Since half of the profits go to rebalancing the pool, we
# are left with half; so divide by 2.
fees: uint256 = unsafe_div(
unsafe_sub(xcp_profit, xcp_profit_a) * ADMIN_FEE, 2 * 10**10
)
# ------------------------------ Claim admin fees by minting admin's share
# of the pool in LP tokens.
# This is the admin fee tokens claimed in self.add_liquidity. We add it to
# the LP token share that the admin needs to claim:
admin_share: uint256 = self.admin_lp_virtual_balance
frac: uint256 = 0
if fee_receiver != empty(address) and fees > 0:
# -------------------------------- Calculate admin share to be minted.
frac = vprice * 10**18 / (vprice - fees) - 10**18
admin_share += current_lp_token_supply * frac / 10**18
# ------ Subtract fees from profits that will be used for rebalancing.
xcp_profit -= fees * 2
# ------------------- Recalculate virtual_price following admin fee claim.
total_supply_including_admin_share: uint256 = (
current_lp_token_supply + admin_share
)
vprice = (
10**18 * self.get_xcp(D, price_scale) /
total_supply_including_admin_share
)
# Do not claim fees if doing so causes virtual price to drop below 10**18.
if vprice < 10**18:
return
# ---------------------------- Update State ------------------------------
# Set admin virtual LP balances to zero because we claimed:
self.admin_lp_virtual_balance = 0
self.xcp_profit = xcp_profit
self.last_admin_fee_claim_timestamp = block.timestamp
# Since we reduce balances: virtual price goes down
self.virtual_price = vprice
# Adjust D after admin seemingly removes liquidity
self.D = D - unsafe_div(D * admin_share, total_supply_including_admin_share)
if xcp_profit > xcp_profit_a:
self.xcp_profit_a = xcp_profit # <-------- Cache last claimed profit.
# --------------------------- Handle Transfers ---------------------------
admin_tokens: uint256[N_COINS] = empty(uint256[N_COINS])
if admin_share > 0:
for i in range(N_COINS):
admin_tokens[i] = (
balances[i] * admin_share /
total_supply_including_admin_share
)
# _transfer_out tokens to admin and update self.balances. State
# update to self.balances occurs before external contract calls:
self._transfer_out(i, admin_tokens[i], fee_receiver)
log ClaimAdminFee(fee_receiver, admin_tokens)
@internal
@pure
def xp(
balances: uint256[N_COINS],
price_scale: uint256,
) -> uint256[N_COINS]:
return [
balances[0] * PRECISIONS[0],
unsafe_div(balances[1] * PRECISIONS[1] * price_scale, PRECISION)
]
@view
@internal
def _A_gamma() -> uint256[2]:
t1: uint256 = self.future_A_gamma_time
A_gamma_1: uint256 = self.future_A_gamma
gamma1: uint256 = A_gamma_1 & 2**128 - 1
A1: uint256 = A_gamma_1 >> 128
if block.timestamp < t1:
# --------------- Handle ramping up and down of A --------------------
A_gamma_0: uint256 = self.initial_A_gamma
t0: uint256 = self.initial_A_gamma_time
t1 -= t0
t0 = block.timestamp - t0
t2: uint256 = t1 - t0
A1 = ((A_gamma_0 >> 128) * t2 + A1 * t0) / t1
gamma1 = ((A_gamma_0 & 2**128 - 1) * t2 + gamma1 * t0) / t1
return [A1, gamma1]
@internal
@view
def _fee(xp: uint256[N_COINS]) -> uint256:
fee_params: uint256[3] = self._unpack_3(self.packed_fee_params)
f: uint256 = xp[0] + xp[1]
f = fee_params[2] * 10**18 / (
fee_params[2] + 10**18 -
(10**18 * N_COINS**N_COINS) * xp[0] / f * xp[1] / f
)
return unsafe_div(
fee_params[0] * f + fee_params[1] * (10**18 - f),
10**18
)
@internal
@pure
def get_xcp(D: uint256, price_scale: uint256) -> uint256:
x: uint256[N_COINS] = [
unsafe_div(D, N_COINS),
D * PRECISION / (price_scale * N_COINS)
]
return isqrt(x[0] * x[1]) # <------------------- Geometric Mean.
@view
@internal
def _calc_token_fee(amounts: uint256[N_COINS], xp: uint256[N_COINS]) -> uint256:
# fee = sum(amounts_i - avg(amounts)) * fee' / sum(amounts)
fee: uint256 = unsafe_div(
unsafe_mul(self._fee(xp), N_COINS),
unsafe_mul(4, unsafe_sub(N_COINS, 1))
)
S: uint256 = 0
for _x in amounts:
S += _x
avg: uint256 = unsafe_div(S, N_COINS)
Sdiff: uint256 = 0
for _x in amounts:
if _x > avg:
Sdiff += unsafe_sub(_x, avg)
else:
Sdiff += unsafe_sub(avg, _x)
return fee * Sdiff / S + NOISE_FEE
@internal
@view
def _calc_withdraw_one_coin(
A_gamma: uint256[2],
token_amount: uint256,
i: uint256,
update_D: bool,
) -> (uint256, uint256, uint256[N_COINS], uint256):
token_supply: uint256 = self.totalSupply
assert token_amount <= token_supply # dev: token amount more than supply
assert i < N_COINS # dev: coin out of range
xx: uint256[N_COINS] = self.balances
D0: uint256 = 0
# -------------------------- Calculate D0 and xp -------------------------
price_scale_i: uint256 = self.cached_price_scale * PRECISIONS[1]
xp: uint256[N_COINS] = [
xx[0] * PRECISIONS[0],
unsafe_div(xx[1] * price_scale_i, PRECISION)
]
if i == 0:
price_scale_i = PRECISION * PRECISIONS[0]
if update_D: # <-------------- D is updated if pool is undergoing a ramp.
D0 = MATH.newton_D(A_gamma[0], A_gamma[1], xp, 0)
else:
D0 = self.D
D: uint256 = D0
# -------------------------------- Fee Calc ------------------------------
# Charge fees on D. Roughly calculate xp[i] after withdrawal and use that
# to calculate fee. Precision is not paramount here: we just want a
# behavior where the higher the imbalance caused the more fee the AMM
# charges.
# xp is adjusted assuming xp[0] ~= xp[1] ~= x[2], which is usually not the
# case. We charge self._fee(xp), where xp is an imprecise adjustment post
# withdrawal in one coin. If the withdraw is too large: charge max fee by
# default. This is because the fee calculation will otherwise underflow.
xp_imprecise: uint256[N_COINS] = xp
xp_correction: uint256 = xp[i] * N_COINS * token_amount / token_supply
fee: uint256 = self._unpack_3(self.packed_fee_params)[1] # <- self.out_fee.
if xp_correction < xp_imprecise[i]:
xp_imprecise[i] -= xp_correction
fee = self._fee(xp_imprecise)
dD: uint256 = unsafe_div(token_amount * D, token_supply)
D_fee: uint256 = fee * dD / (2 * 10**10) + 1 # <------- Actual fee on D.
# --------- Calculate `approx_fee` (assuming balanced state) in ith token.
# -------------------------------- We only need this for fee in the event.
approx_fee: uint256 = N_COINS * D_fee * xx[i] / D # <------------------<---------- TODO: Check math.
# ------------------------------------------------------------------------
D -= (dD - D_fee) # <----------------------------------- Charge fee on D.
# --------------------------------- Calculate `y_out`` with `(D - D_fee)`.
y: uint256 = MATH.get_y(A_gamma[0], A_gamma[1], xp, D, i)[0]
dy: uint256 = (xp[i] - y) * PRECISION / price_scale_i
xp[i] = y
return dy, D, xp, approx_fee
# ------------------------ ERC20 functions -----------------------------------
@internal
def _approve(_owner: address, _spender: address, _value: uint256):
self.allowance[_owner][_spender] = _value
log Approval(_owner, _spender, _value)
@internal
def _transfer(_from: address, _to: address, _value: uint256):
assert _to not in [self, empty(address)]
self.balanceOf[_from] -= _value
self.balanceOf[_to] += _value
log Transfer(_from, _to, _value)
@view
@internal
def _domain_separator() -> bytes32:
if chain.id != CACHED_CHAIN_ID:
return keccak256(
_abi_encode(
EIP712_TYPEHASH,
NAME_HASH,
VERSION_HASH,
chain.id,
self,
salt,
)
)
return CACHED_DOMAIN_SEPARATOR
@external
def transferFrom(_from: address, _to: address, _value: uint256) -> bool:
"""
@dev Transfer tokens from one address to another.
@param _from address The address which you want to send tokens from
@param _to address The address which you want to transfer to
@param _value uint256 the amount of tokens to be transferred
@return bool True on successul transfer. Reverts otherwise.
"""
_allowance: uint256 = self.allowance[_from][msg.sender]
if _allowance != max_value(uint256):
self._approve(_from, msg.sender, _allowance - _value)
self._transfer(_from, _to, _value)
return True
@external
def transfer(_to: address, _value: uint256) -> bool:
"""
@dev Transfer token for a specified address
@param _to The address to transfer to.
@param _value The amount to be transferred.
@return bool True on successful transfer. Reverts otherwise.
"""
self._transfer(msg.sender, _to, _value)
return True
@external
def approve(_spender: address, _value: uint256) -> bool:
"""
@notice Allow `_spender` to transfer up to `_value` amount
of tokens from the caller's account.
@param _spender The account permitted to spend up to `_value` amount of
caller's funds.
@param _value The amount of tokens `_spender` is allowed to spend.
@return bool Success
"""
self._approve(msg.sender, _spender, _value)
return True
@external
def permit(
_owner: address,
_spender: address,
_value: uint256,
_deadline: uint256,
_v: uint8,
_r: bytes32,
_s: bytes32,
) -> bool:
"""
@notice Permit `_spender` to spend up to `_value` amount of `_owner`'s
tokens via a signature.
@dev In the event of a chain fork, replay attacks are prevented as
domain separator is recalculated. However, this is only if the
resulting chains update their chainId.
@param _owner The account which generated the signature and is granting an
allowance.
@param _spender The account which will be granted an allowance.
@param _value The approval amount.
@param _deadline The deadline by which the signature must be submitted.
@param _v The last byte of the ECDSA signature.
@param _r The first 32 bytes of the ECDSA signature.
@param _s The second 32 bytes of the ECDSA signature.
@return bool Success.
"""
assert _owner != empty(address) # dev: invalid owner
assert block.timestamp <= _deadline # dev: permit expired
nonce: uint256 = self.nonces[_owner]
digest: bytes32 = keccak256(
concat(
b"\x19\x01",
self._domain_separator(),
keccak256(
_abi_encode(
EIP2612_TYPEHASH, _owner, _spender, _value, nonce, _deadline
)
),
)
)
assert ecrecover(digest, _v, _r, _s) == _owner # dev: invalid signature
self.nonces[_owner] = unsafe_add(nonce, 1) # <-- Unsafe add is safe here.
self._approve(_owner, _spender, _value)
return True
@internal
def mint(_to: address, _value: uint256) -> bool:
"""
@dev Mint an amount of the token and assigns it to an account.
This encapsulates the modification of balances such that the
proper events are emitted.
@param _to The account that will receive the created tokens.
@param _value The amount that will be created.
@return bool Success.
"""
self.totalSupply += _value
self.balanceOf[_to] += _value
log Transfer(empty(address), _to, _value)
return True
@internal
def burnFrom(_to: address, _value: uint256) -> bool:
"""
@dev Burn an amount of the token from a given account.
@param _to The account whose tokens will be burned.
@param _value The amount that will be burned.
@return bool Success.
"""
self.totalSupply -= _value
self.balanceOf[_to] -= _value
log Transfer(_to, empty(address), _value)
return True
# ------------------------- AMM View Functions -------------------------------
@internal
@view
def internal_price_oracle() -> uint256:
"""
@notice Returns the oracle price of the coin at index `k` w.r.t the coin
at index 0.
@dev The oracle is an exponential moving average, with a periodicity
determined by `self.ma_time`. The aggregated prices are cached state
prices (dy/dx) calculated AFTER the latest trade.
@param k The index of the coin.
@return uint256 Price oracle value of kth coin.
"""
price_oracle: uint256 = self.cached_price_oracle
price_scale: uint256 = self.cached_price_scale
last_prices_timestamp: uint256 = self.last_timestamp
if last_prices_timestamp < block.timestamp: # <------------ Update moving
# average if needed.
last_prices: uint256 = self.last_prices
ma_time: uint256 = self._unpack_3(self.packed_rebalancing_params)[2]
alpha: uint256 = MATH.wad_exp(
-convert(
unsafe_sub(block.timestamp, last_prices_timestamp) * 10**18 / ma_time,
int256,
)
)
# ---- We cap state price that goes into the EMA with 2 x price_scale.
return (
min(last_prices, 2 * price_scale) * (10**18 - alpha) +
price_oracle * alpha
) / 10**18
return price_oracle
@external
@view
def fee_receiver() -> address:
"""
@notice Returns the address of the admin fee receiver.
@return address Fee receiver.
"""
return factory.fee_receiver()
@external
@view
def admin() -> address:
"""
@notice Returns the address of the pool's admin.
@return address Admin.
"""
return factory.admin()
@external
@view
def calc_token_amount(amounts: uint256[N_COINS], deposit: bool) -> uint256:
"""
@notice Calculate LP tokens minted or to be burned for depositing or
removing `amounts` of coins
@dev Includes fee.
@param amounts Amounts of tokens being deposited or withdrawn
@param deposit True if it is a deposit action, False if withdrawn.
@return uint256 Amount of LP tokens deposited or withdrawn.
"""
view_contract: address = factory.views_implementation()
return Views(view_contract).calc_token_amount(amounts, deposit, self)
@external
@view
def get_dy(i: uint256, j: uint256, dx: uint256) -> uint256:
"""
@notice Get amount of coin[j] tokens received for swapping in dx amount of coin[i]
@dev Includes fee.
@param i index of input token. Check pool.coins(i) to get coin address at ith index
@param j index of output token
@param dx amount of input coin[i] tokens
@return uint256 Exact amount of output j tokens for dx amount of i input tokens.
"""
view_contract: address = factory.views_implementation()
return Views(view_contract).get_dy(i, j, dx, self)
@external
@view
def get_dx(i: uint256, j: uint256, dy: uint256) -> uint256:
"""
@notice Get amount of coin[i] tokens to input for swapping out dy amount
of coin[j]
@dev This is an approximate method, and returns estimates close to the input
amount. Expensive to call on-chain.
@param i index of input token. Check pool.coins(i) to get coin address at
ith index
@param j index of output token
@param dy amount of input coin[j] tokens received
@return uint256 Approximate amount of input i tokens to get dy amount of j tokens.
"""
view_contract: address = factory.views_implementation()
return Views(view_contract).get_dx(i, j, dy, self)
@external
@view
@nonreentrant("lock")
def lp_price() -> uint256:
"""
@notice Calculates the current price of the LP token w.r.t coin at the
0th index
@return uint256 LP price.
"""
return 2 * self.virtual_price * isqrt(self.internal_price_oracle() * 10**18) / 10**18
@external
@view
@nonreentrant("lock")
def get_virtual_price() -> uint256:
"""
@notice Calculates the current virtual price of the pool LP token.
@dev Not to be confused with `self.virtual_price` which is a cached
virtual price.
@return uint256 Virtual Price.
"""
return 10**18 * self.get_xcp(self.D, self.cached_price_scale) / self.totalSupply
@external
@view
@nonreentrant("lock")
def price_oracle() -> uint256:
"""
@notice Returns the oracle price of the coin at index `k` w.r.t the coin
at index 0.
@dev The oracle is an exponential moving average, with a periodicity
determined by `self.ma_time`. The aggregated prices are cached state
prices (dy/dx) calculated AFTER the latest trade.
@return uint256 Price oracle value of kth coin.
"""
return self.internal_price_oracle()
@external
@view
@nonreentrant("lock")
def price_scale() -> uint256:
"""
@notice Returns the price scale of the coin at index `k` w.r.t the coin
at index 0.
@dev Price scale determines the price band around which liquidity is
concentrated.
@return uint256 Price scale of coin.
"""
return self.cached_price_scale
@external
@view
def fee() -> uint256:
"""
@notice Returns the fee charged by the pool at current state.
@dev Not to be confused with the fee charged at liquidity action, since
there the fee is calculated on `xp` AFTER liquidity is added or
removed.
@return uint256 fee bps.
"""
return self._fee(self.xp(self.balances, self.cached_price_scale))
@view
@external
def calc_withdraw_one_coin(token_amount: uint256, i: uint256) -> uint256:
"""
@notice Calculates output tokens with fee
@param token_amount LP Token amount to burn
@param i token in which liquidity is withdrawn
@return uint256 Amount of ith tokens received for burning token_amount LP tokens.
"""
return self._calc_withdraw_one_coin(
self._A_gamma(),
token_amount,
i,
(self.future_A_gamma_time > block.timestamp)
)[0]
@external
@view
def calc_token_fee(
amounts: uint256[N_COINS], xp: uint256[N_COINS]
) -> uint256:
"""
@notice Returns the fee charged on the given amounts for add_liquidity.
@param amounts The amounts of coins being added to the pool.
@param xp The current balances of the pool multiplied by coin precisions.
@return uint256 Fee charged.
"""
return self._calc_token_fee(amounts, xp)
@view
@external
def A() -> uint256:
"""
@notice Returns the current pool amplification parameter.
@return uint256 A param.
"""
return self._A_gamma()[0]
@view
@external
def gamma() -> uint256:
"""
@notice Returns the current pool gamma parameter.
@return uint256 gamma param.
"""
return self._A_gamma()[1]
@view
@external
def mid_fee() -> uint256:
"""
@notice Returns the current mid fee
@return uint256 mid_fee value.
"""
return self._unpack_3(self.packed_fee_params)[0]
@view
@external
def out_fee() -> uint256:
"""
@notice Returns the current out fee
@return uint256 out_fee value.
"""
return self._unpack_3(self.packed_fee_params)[1]
@view
@external
def fee_gamma() -> uint256:
"""
@notice Returns the current fee gamma
@return uint256 fee_gamma value.
"""
return self._unpack_3(self.packed_fee_params)[2]
@view
@external
def allowed_extra_profit() -> uint256:
"""
@notice Returns the current allowed extra profit
@return uint256 allowed_extra_profit value.
"""
return self._unpack_3(self.packed_rebalancing_params)[0]
@view
@external
def adjustment_step() -> uint256:
"""
@notice Returns the current adjustment step
@return uint256 adjustment_step value.
"""
return self._unpack_3(self.packed_rebalancing_params)[1]
@view
@external
def ma_time() -> uint256:
"""
@notice Returns the current moving average time in seconds
@dev To get time in seconds, the parameter is multipled by ln(2)
One can expect off-by-one errors here.
@return uint256 ma_time value.
"""
return self._unpack_3(self.packed_rebalancing_params)[2] * 694 / 1000
@view
@external
def precisions() -> uint256[N_COINS]: # <-------------- For by view contract.
"""
@notice Returns the precisions of each coin in the pool.
@return uint256[3] precisions of coins.
"""
return PRECISIONS
@external
@view
def fee_calc(xp: uint256[N_COINS]) -> uint256: # <----- For by view contract.
"""
@notice Returns the fee charged by the pool at current state.
@param xp The current balances of the pool multiplied by coin precisions.
@return uint256 Fee value.
"""
return self._fee(xp)
@view
@external
def DOMAIN_SEPARATOR() -> bytes32:
"""
@notice EIP712 domain separator.
@return bytes32 Domain Separator set for the current chain.
"""
return self._domain_separator()
# ------------------------- AMM Admin Functions ------------------------------
@external
def ramp_A_gamma(
future_A: uint256, future_gamma: uint256, future_time: uint256
):
"""
@notice Initialise Ramping A and gamma parameter values linearly.
@dev Only accessible by factory admin, and only
@param future_A The future A value.
@param future_gamma The future gamma value.
@param future_time The timestamp at which the ramping will end.
"""
assert msg.sender == factory.admin() # dev: only owner
assert block.timestamp > self.future_A_gamma_time # dev: ramp undergoing
assert future_time > block.timestamp + MIN_RAMP_TIME - 1 # dev: insufficient time
A_gamma: uint256[2] = self._A_gamma()
initial_A_gamma: uint256 = A_gamma[0] << 128
initial_A_gamma = initial_A_gamma | A_gamma[1]
assert future_A > MIN_A - 1
assert future_A < MAX_A + 1
assert future_gamma > MIN_GAMMA - 1
assert future_gamma < MAX_GAMMA + 1
ratio: uint256 = 10**18 * future_A / A_gamma[0]
assert ratio < 10**18 * MAX_A_CHANGE + 1 # dev: A change too high
assert ratio > 10**18 / MAX_A_CHANGE - 1 # dev: A change too low
ratio = 10**18 * future_gamma / A_gamma[1]
assert ratio < 10**18 * MAX_A_CHANGE + 1 # dev: gamma change too high
assert ratio > 10**18 / MAX_A_CHANGE - 1 # dev: gamma change too low
self.initial_A_gamma = initial_A_gamma
self.initial_A_gamma_time = block.timestamp
future_A_gamma: uint256 = future_A << 128
future_A_gamma = future_A_gamma | future_gamma
self.future_A_gamma_time = future_time
self.future_A_gamma = future_A_gamma
log RampAgamma(
A_gamma[0],
future_A,
A_gamma[1],
future_gamma,
block.timestamp,
future_time,
)
@external
def stop_ramp_A_gamma():
"""
@notice Stop Ramping A and gamma parameters immediately.
@dev Only accessible by factory admin.
"""
assert msg.sender == factory.admin() # dev: only owner
A_gamma: uint256[2] = self._A_gamma()
current_A_gamma: uint256 = A_gamma[0] << 128
current_A_gamma = current_A_gamma | A_gamma[1]
self.initial_A_gamma = current_A_gamma
self.future_A_gamma = current_A_gamma
self.initial_A_gamma_time = block.timestamp
self.future_A_gamma_time = block.timestamp
# ------ Now (block.timestamp < t1) is always False, so we return saved A.
log StopRampA(A_gamma[0], A_gamma[1], block.timestamp)
@external
@nonreentrant('lock')
def apply_new_parameters(
_new_mid_fee: uint256,
_new_out_fee: uint256,
_new_fee_gamma: uint256,
_new_allowed_extra_profit: uint256,
_new_adjustment_step: uint256,
_new_ma_time: uint256,
):
"""
@notice Commit new parameters.
@dev Only accessible by factory admin.
@param _new_mid_fee The new mid fee.
@param _new_out_fee The new out fee.
@param _new_fee_gamma The new fee gamma.
@param _new_allowed_extra_profit The new allowed extra profit.
@param _new_adjustment_step The new adjustment step.
@param _new_ma_time The new ma time. ma_time is time_in_seconds/ln(2).
"""
assert msg.sender == factory.admin() # dev: only owner
# ----------------------------- Set fee params ---------------------------
new_mid_fee: uint256 = _new_mid_fee
new_out_fee: uint256 = _new_out_fee
new_fee_gamma: uint256 = _new_fee_gamma
current_fee_params: uint256[3] = self._unpack_3(self.packed_fee_params)
if new_out_fee < MAX_FEE + 1:
assert new_out_fee > MIN_FEE - 1 # dev: fee is out of range
else:
new_out_fee = current_fee_params[1]
if new_mid_fee > MAX_FEE:
new_mid_fee = current_fee_params[0]
assert new_mid_fee <= new_out_fee # dev: mid-fee is too high
if new_fee_gamma < 10**18:
assert new_fee_gamma > 0 # dev: fee_gamma out of range [1 .. 10**18]
else:
new_fee_gamma = current_fee_params[2]
self.packed_fee_params = self._pack_3([new_mid_fee, new_out_fee, new_fee_gamma])
# ----------------- Set liquidity rebalancing parameters -----------------
new_allowed_extra_profit: uint256 = _new_allowed_extra_profit
new_adjustment_step: uint256 = _new_adjustment_step
new_ma_time: uint256 = _new_ma_time
current_rebalancing_params: uint256[3] = self._unpack_3(self.packed_rebalancing_params)
if new_allowed_extra_profit > 10**18:
new_allowed_extra_profit = current_rebalancing_params[0]
if new_adjustment_step > 10**18:
new_adjustment_step = current_rebalancing_params[1]
if new_ma_time < 872542: # <----- Calculated as: 7 * 24 * 60 * 60 / ln(2)
assert new_ma_time > 86 # dev: MA time should be longer than 60/ln(2)
else:
new_ma_time = current_rebalancing_params[2]
self.packed_rebalancing_params = self._pack_3(
[new_allowed_extra_profit, new_adjustment_step, new_ma_time]
)
# ---------------------------------- LOG ---------------------------------
log NewParameters(
new_mid_fee,
new_out_fee,
new_fee_gamma,
new_allowed_extra_profit,
new_adjustment_step,
new_ma_time,
)