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@bout3fiddy
bout3fiddy committed Jun 13, 2024
1 parent b0269d3 commit a144b1a
Showing 1 changed file with 115 additions and 103 deletions.
218 changes: 115 additions & 103 deletions contracts/main/CurveStableSwapNGViews.vy
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Original file line number Diff line number Diff line change
Expand Up @@ -20,22 +20,17 @@ interface StableSwapNG:
def A() -> uint256: view
def calc_withdraw_one_coin(_token_amount: uint256, i: int128) -> uint256: view
def totalSupply() -> uint256: view
def calc_token_amount(amounts: DynArray[uint256, MAX_COINS], deposit: bool) -> uint256: view
def offpeg_fee_multiplier() -> uint256: view

interface StableSwap2:
def calc_token_amount(amounts: uint256[2], deposit: bool) -> uint256: view

interface StableSwap3:
def calc_token_amount(amounts: uint256[3], deposit: bool) -> uint256: view


A_PRECISION: constant(uint256) = 100
MAX_COINS: constant(uint256) = 8
PRECISION: constant(uint256) = 10 ** 18
FEE_DENOMINATOR: constant(uint256) = 10 ** 10


VERSION: public(constant(String[8])) = "1.1.0"


# ------------------------------ Public Getters ------------------------------


Expand Down Expand Up @@ -99,6 +94,7 @@ def get_dx_underlying(
BASE_N_COINS: uint256 = StableSwapNG(pool).BASE_N_COINS()
N_COINS: uint256 = StableSwapNG(pool).N_COINS()
base_pool_has_static_fee: bool = self._has_static_fee(BASE_POOL)
base_pool_lp_token: address = StableSwapNG(pool).coins(1)

# CASE 1: Swap does not involve Metapool at all. In this case, we kindly ask the user
# to use the right pool for their swaps.
Expand All @@ -114,7 +110,7 @@ def get_dx_underlying(
if i == 0:
# Calculate LP tokens that are burnt to receive dy amount of base_j tokens.
lp_amount_burnt: uint256 = self._base_calc_token_amount(
dy, j - 1, BASE_N_COINS, BASE_POOL, False
dy, j - 1, BASE_N_COINS, BASE_POOL, base_pool_lp_token, False,
)
return self._get_dx(0, 1, lp_amount_burnt, pool, False, N_COINS)

Expand Down Expand Up @@ -225,83 +221,19 @@ def calc_token_amount(
) -> uint256:
"""
@notice Calculate addition or reduction in token supply from a deposit or withdrawal
@dev Only works for StableswapNG pools and not legacy versions
@param _amounts Amount of each coin being deposited
@param _is_deposit set True for deposits, False for withdrawals
@return Expected amount of LP tokens received
"""
amp: uint256 = StableSwapNG(pool).A() * A_PRECISION
N_COINS: uint256 = StableSwapNG(pool).N_COINS()

rates: DynArray[uint256, MAX_COINS] = empty(DynArray[uint256, MAX_COINS])
old_balances: DynArray[uint256, MAX_COINS] = empty(DynArray[uint256, MAX_COINS])
xp: DynArray[uint256, MAX_COINS] = empty(DynArray[uint256, MAX_COINS])
rates, old_balances, xp = self._get_rates_balances_xp(pool, N_COINS)

# Initial invariant
D0: uint256 = self.get_D(xp, amp, N_COINS)

total_supply: uint256 = StableSwapNG(pool).totalSupply()
new_balances: DynArray[uint256, MAX_COINS] = old_balances
for i in range(MAX_COINS):
if i == N_COINS:
break

amount: uint256 = _amounts[i]
if _is_deposit:
new_balances[i] += amount
else:
new_balances[i] -= amount

# Invariant after change
for idx in range(MAX_COINS):
if idx == N_COINS:
break
xp[idx] = rates[idx] * new_balances[idx] / PRECISION
D1: uint256 = self.get_D(xp, amp, N_COINS)

# We need to recalculate the invariant accounting for fees
# to calculate fair user's share
D2: uint256 = D1
if total_supply > 0:

# Only account for fees if we are not the first to deposit
base_fee: uint256 = StableSwapNG(pool).fee() * N_COINS / (4 * (N_COINS - 1))
fee_multiplier: uint256 = StableSwapNG(pool).offpeg_fee_multiplier()
_dynamic_fee_i: uint256 = 0
xs: uint256 = 0
ys: uint256 = (D0 + D1) / N_COINS

for i in range(MAX_COINS):
if i == N_COINS:
break

ideal_balance: uint256 = D1 * old_balances[i] / D0
difference: uint256 = 0
new_balance: uint256 = new_balances[i]
if ideal_balance > new_balance:
difference = ideal_balance - new_balance
else:
difference = new_balance - ideal_balance

xs = rates[i] * (old_balances[i] + new_balance) / PRECISION
_dynamic_fee_i = self._dynamic_fee(xs, ys, base_fee, fee_multiplier)
new_balances[i] -= _dynamic_fee_i * difference / FEE_DENOMINATOR

for idx in range(MAX_COINS):
if idx == N_COINS:
break
xp[idx] = rates[idx] * new_balances[idx] / PRECISION

D2 = self.get_D(xp, amp, N_COINS)
else:
return D1 # Take the dust if there was any

diff: uint256 = 0
if _is_deposit:
diff = D2 - D0
else:
diff = D0 - D2
return diff * total_supply / D0
return self._calc_token_amount(
_amounts,
_is_deposit,
pool,
pool,
StableSwapNG(pool).N_COINS()
)


@view
Expand Down Expand Up @@ -449,36 +381,116 @@ def _dynamic_fee(xpi: uint256, xpj: uint256, _fee: uint256, _fee_multiplier: uin

@internal
@view
def _base_calc_token_amount(
dx: uint256,
base_i: int128,
base_n_coins: uint256,
base_pool: address,
is_deposit: bool
def _calc_token_amount(
_amounts: uint256[MAX_COINS],
is_deposit: bool,
pool: address,
pool_lp_token: address,
n_coins: uint256,
) -> uint256:
base_pool_is_ng: bool = raw_call(base_pool, method_id("D_ma_time()"), revert_on_failure=False, is_static_call=True)

if base_n_coins == 2 and not base_pool_is_ng:
amp: uint256 = StableSwapNG(pool).A() * A_PRECISION
N_COINS: uint256 = StableSwapNG(pool).N_COINS()

base_inputs: uint256[2] = empty(uint256[2])
base_inputs[base_i] = dx
return StableSwap2(base_pool).calc_token_amount(base_inputs, is_deposit)
rates: DynArray[uint256, MAX_COINS] = empty(DynArray[uint256, MAX_COINS])
old_balances: DynArray[uint256, MAX_COINS] = empty(DynArray[uint256, MAX_COINS])
xp: DynArray[uint256, MAX_COINS] = empty(DynArray[uint256, MAX_COINS])

elif base_n_coins == 3 and not base_pool_is_ng:
pool_is_ng: bool = raw_call(base_pool, method_id("D_ma_time()"), revert_on_failure=False, is_static_call=True)
if pool_is_ng:
rates, old_balances, xp = self._get_rates_balances_xp(pool, N_COINS)
else:
... # TODO: accommodate if pool is not ng (but: cannot fully accommodate in a simple manner)

base_inputs: uint256[3] = empty(uint256[3])
base_inputs[base_i] = dx
return StableSwap3(base_pool).calc_token_amount(base_inputs, is_deposit)
# Initial invariant
D0: uint256 = self.get_D(xp, amp, N_COINS)

else:
total_supply: uint256 = StableSwapNG(pool).totalSupply()
new_balances: DynArray[uint256, MAX_COINS] = old_balances
for i in range(MAX_COINS):
if i == N_COINS:
break

amount: uint256 = _amounts[i]
if _is_deposit:
new_balances[i] += amount
else:
new_balances[i] -= amount

# Invariant after change
for idx in range(MAX_COINS):
if idx == N_COINS:
break
xp[idx] = rates[idx] * new_balances[idx] / PRECISION
D1: uint256 = self.get_D(xp, amp, N_COINS)

# We need to recalculate the invariant accounting for fees
# to calculate fair user's share
D2: uint256 = D1
if total_supply > 0:

# Only account for fees if we are not the first to deposit
base_fee: uint256 = StableSwapNG(pool).fee() * N_COINS / (4 * (N_COINS - 1))
fee_multiplier: uint256 = StableSwapNG(pool).offpeg_fee_multiplier()
_dynamic_fee_i: uint256 = 0
xs: uint256 = 0
ys: uint256 = (D0 + D1) / N_COINS

for i in range(MAX_COINS):
if i == N_COINS:
break

base_inputs: DynArray[uint256, MAX_COINS] = empty(DynArray[uint256, MAX_COINS])
for i in range(base_n_coins, bound=MAX_COINS):
if i == convert(base_i, uint256):
base_inputs.append(dx)
ideal_balance: uint256 = D1 * old_balances[i] / D0
difference: uint256 = 0
new_balance: uint256 = new_balances[i]
if ideal_balance > new_balance:
difference = ideal_balance - new_balance
else:
base_inputs.append(0)
return StableSwapNG(base_pool).calc_token_amount(base_inputs, is_deposit)
difference = new_balance - ideal_balance

xs = rates[i] * (old_balances[i] + new_balance) / PRECISION
_dynamic_fee_i = self._dynamic_fee(xs, ys, base_fee, fee_multiplier)
new_balances[i] -= _dynamic_fee_i * difference / FEE_DENOMINATOR

for idx in range(MAX_COINS):
if idx == N_COINS:
break
xp[idx] = rates[idx] * new_balances[idx] / PRECISION

D2 = self.get_D(xp, amp, N_COINS)
else:
return D1 # Take the dust if there was any

diff: uint256 = 0
if _is_deposit:
diff = D2 - D0
else:
diff = D0 - D2
return diff * total_supply / D0


@internal
@view
def _base_calc_token_amount(
dx: uint256,
base_i: int128,
base_n_coins: uint256,
base_pool: address,
base_pool_lp_token: address,
is_deposit: bool,
) -> uint256:

base_pool_is_ng: bool = raw_call(base_pool, method_id("D_ma_time()"), revert_on_failure=False, is_static_call=True)
base_inputs: uint256[MAX_COINS] = empty(uint256[MAX_COINS])
base_inputs[base_i] = dx

return self._calc_token_amount(
base_inputs,
is_deposit,
base_pool,
base_pool_lp_token,
base_n_coins
)


@internal
Expand Down

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