def _cash(self, cdtbalance, cdtsupply, cdtamount):
# check overflow and change unit
cdtbalance = math.uint256(cdtbalance)
cdtsupply = math.uint256(cdtsupply)
cdtamount = math.uint256(cdtamount)
cdtbalance = math.ethertofloat(cdtbalance)
cdtsupply = math.ethertofloat(cdtsupply)
cdtamount = math.ethertofloat(cdtamount)
# Approximate calculation for it is always less than actual amount
cdtprice = math.div(
cdtbalance,
math.mul(cdtsupply,
math.decimaltofloat(self.CDT_CRR * self.decimal)))
ethamount = math.mul(cdtamount, cdtprice)
assert ethamount < cdtbalance
cashfee = math.mul(
ethamount, math.decimaltofloat(self.CDT_CASHFEE * self.decimal))
ethamount = math.sub(ethamount, cashfee)
cdtbalance = math.sub(cdtbalance, ethamount)
cdtprice = math.div(
cdtbalance,
math.mul(cdtsupply,
math.decimaltofloat(self.CDT_CRR * self.decimal)))
return math.floattoether(ethamount), math.floattodecimal(cdtprice)
def _sigmoid(a, b, l, d, x):
assert a > 0
assert b >= 0
assert l >= 0
assert d > 0
if x > l:
rate = math.div(math.safeSub(x, l), d)
if rate >> (math.PRECISION - math.MIN_PRECISION) < 0x1e00000000:
exp = math.exp(rate)
addexp = math.add(math.float(1), exp)
divexp = math.div(math.float(1), addexp)
mulexp = math.mul(a, divexp)
y = math.add(mulexp, b)
else:
y = b
elif (x < l) and (x >= 0):
rate = math.div(math.safeSub(l, x), d)
if rate >> (math.PRECISION - math.MIN_PRECISION) < 0x1e00000000:
exp = math.exp(rate)
addexp = math.add(math.float(1), exp)
divexp = math.div(math.float(1), addexp)
mulexp = math.mul(a, divexp)
y = math.sub(math.add(a, b * 2), math.add(mulexp, b))
else:
y = math.add(a, b)
else:
y = math.div(math.add(a, b * 2), math.float(2))
return y
def _withdraw(self, dptbalance, dptcirculation, dptamount):
# check overflow and change unit
dptbalance = math.uint256(dptbalance)
dptcirculation = math.uint256(dptcirculation)
dptamount = math.uint256(dptamount)
dptbalance = math.ethertofloat(dptbalance)
dptcirculation = math.ethertofloat(dptcirculation)
dptamount = math.ethertofloat(dptamount)
dptprice = math.div(
dptbalance, math.mul(dptcirculation,
self._get_crr(dptcirculation)))
# Calculate the maximum ether should be returned to user
ethamount = math.mul(dptamount, dptprice)
# Calculate the maximum CRR after withdraw
max_crr = self._get_crr(math.sub(dptcirculation, dptamount))
# Calculate the minimum price after withdraw
dptprice = math.div(math.sub(dptbalance, ethamount),
math.mul(dptcirculation, max_crr))
# the actual withdraw price of DPT is equal to the minimum possible price after withdraw, ether=DPT*P
actual_ether = math.mul(dptamount, dptprice)
return math.floattoether(actual_ether), math.floattodecimal(
max_crr), math.floattodecimal(dptprice)
def _sigmoid(a, b, l, d, x):
assert a > 0
assert b >= 0
assert l >= 0
assert d > 0
if x > l:
rate = math.div(math.safeSub(x, l), d)
if rate < 0x1e00000000:
exp = math.fixedExp(rate)
addexp = math.add(1 << 32, exp)
divexp = math.div(1 << 32, addexp)
mulexp = math.mul(a, divexp)
y = math.add(mulexp, b)
else:
y = b
elif (x < l) and (x >= 0):
rate = math.div(math.safeSub(l, x), d)
if rate < 0x1e00000000:
exp = math.fixedExp(rate)
addexp = math.add(1 << 32, exp)
divexp = math.div(1 << 32, addexp)
mulexp = math.mul(a, divexp)
y = math.sub(math.add(a, b * 2), math.add(mulexp, b))
else:
y = math.add(a, b)
else:
y = math.div(math.add(a, b * 2), math.float(2))
return y
def _get_loan_plan(self, supply, circulation):
# check over flow and change unit
high = math.decimaltofloat(self.high * self.decimal)
low = math.decimaltofloat(self.low * self.decimal)
supply = math.uint256(supply)
circulation = math.uint256(circulation)
supply = math.ethertofloat(supply)
circulation = math.ethertofloat(circulation)
assert 0 < supply
assert 0 < circulation
return math.floattodecimal(
_sigmoid(high - low, low, math.div(supply, math.float(2)),
math.div(supply, math.float(8)), circulation)
), self.loandays * 24 * 3600, self.exemptdays * 24 * 3600
def _loan(self, cdtamount, interestrate, crr):
# check overflow and change unit
cdtamount = math.uint256(cdtamount)
interestrate = math.uint256(interestrate)
crr = math.uint256(crr)
cdtamount = math.ethertofloat(cdtamount)
interestrate = math.decimaltofloat(interestrate)
crr = math.decimaltofloat(crr)
# loaned ether
ethamount = math.mul(cdtamount,
math.decimaltofloat(self.CDTL * self.decimal))
# calculate the interest
earn = math.mul(ethamount, interestrate)
cdtreserve = math.mul(
earn, math.decimaltofloat(self.CDT_RESERVE * self.decimal))
interest = math.sub(earn, cdtreserve)
issuecdtamount = math.div(
math.mul(earn, crr),
math.decimaltofloat(self.CDTIP * self.decimal))
# calculate the new issue CDT to prize loaned user using the interest
ethamount = math.sub(ethamount, earn)
sctamount = cdtamount
return math.floattoether(ethamount), math.floattoether(
interest), math.floattoether(issuecdtamount), math.floattoether(
sctamount)
def _issue(self, circulation, ethamount):
# check over flow and change unit
circulation = math.uint256(circulation)
ethamount = math.uint256(ethamount)
circulation = math.ethertofloat(circulation)
ethamount = math.ethertofloat(ethamount)
crr = self._get_crr(circulation)
ethdpt = math.mul(ethamount, crr)
dpt = math.div(ethdpt, math.decimaltofloat(self.DPTIP * self.decimal))
cdt = math.div(math.mul(math.sub(math.float(1), crr), ethamount),
math.decimaltofloat(self.CDTIP * self.decimal))
crr = self._get_crr(circulation)
# Split the new issued tokens to User and Founder
udpt = math.mul(dpt, math.decimaltofloat(self.U * self.decimal))
ucdt = math.mul(cdt, math.decimaltofloat(self.U * self.decimal))
fdpt = math.mul(dpt, math.decimaltofloat(self.F * self.decimal))
fcdt = math.mul(cdt, math.decimaltofloat(self.F * self.decimal))
return math.floattoether(udpt), math.floattoether(
ucdt), math.floattoether(fdpt), math.floattoether(
fcdt), math.floattoether(ethdpt), math.floattodecimal(crr)
def _to_credit_token(self, repayethamount, dctamount):
# check over float and change unit
repayethamount = math.uint256(repayethamount)
dctamount = math.uint256(dctamount)
repayethamount = math.ethertofloat(repayethamount)
dctamount = math.ethertofloat(dctamount)
ethamount = math.mul(dctamount,
math.decimaltofloat(self.CDTL * self.decimal))
if repayethamount < ethamount:
ethamount = repayethamount
cdtamount = math.div(ethamount,
math.decimaltofloat(self.CDTL * self.decimal))
refunddctamount = math.sub(dctamount, cdtamount)
return 0, math.floattoether(cdtamount), math.floattoether(
refunddctamount)
else:
cdtamount = math.div(ethamount,
math.decimaltofloat(self.CDTL * self.decimal))
refundethamount = math.sub(repayethamount, ethamount)
return math.floattoether(refundethamount), math.floattoether(
cdtamount), 0
def _repay(self, repayethamount, sctamount):
# check overflow and change unit
repayethamount = math.uint256(repayethamount)
sctamount = math.uint256(sctamount)
repayethamount = math.ethertofloat(repayethamount)
sctamount = math.ethertofloat(sctamount)
ethamount = math.mul(sctamount,
math.decimaltofloat(self.CDTL * self.decimal))
if repayethamount < ethamount:
ethamount = repayethamount
cdtamount = math.div(ethamount,
math.decimaltofloat(self.CDTL * self.decimal))
refundsctamount = math.sub(sctamount, cdtamount)
return 0, math.floattoether(cdtamount), math.floattoether(
refundsctamount)
else:
cdtamount = math.div(ethamount,
math.decimaltofloat(self.CDTL * self.decimal))
refundethamount = math.sub(repayethamount, ethamount)
return math.floattoether(refundethamount), math.floattoether(
cdtamount), 0
def _to_discredit_token(self, cdtbalance, supply, sctamount):
# check overflow and change unit
cdtbalance = math.uint256(cdtbalance)
supply = math.uint256(supply)
sctamount = math.uint256(sctamount)
cdtbalance = math.ethertofloat(cdtbalance)
supply = math.ethertofloat(supply)
sctamount = math.ethertofloat(sctamount)
cdtprice = math.div(
cdtbalance,
math.mul(supply, math.decimaltofloat(self.CDT_CRR * self.decimal)))
return math.floattoether(
math.mul(sctamount, math.decimaltofloat(
0.8 * self.decimal))), math.floattodecimal(cdtprice)
def _deposit(self, dptbalance, dptsupply, dptcirculation, ethamount):
# check overflow and change unit
dptbalance = math.uint256(dptbalance)
dptsupply = math.uint256(dptsupply)
dptcirculation = math.uint256(dptcirculation)
ethamount = math.uint256(ethamount)
dptbalance = math.ethertofloat(dptbalance)
dptsupply = math.ethertofloat(dptsupply)
dptcirculation = math.ethertofloat(dptcirculation)
ethamount = math.ethertofloat(ethamount)
# Calculate current CRR and price of DPT
crr = self._get_crr(dptcirculation)
dptprice = math.div(dptbalance, math.mul(dptcirculation, crr))
# Calculate the maximum DPT should be gave to user
token = math.div(ethamount, dptprice)
# Calculate the maximum balance of DPT contract
max_balance = math.add(dptbalance, ethamount)
# Calculate the minimum CRR of DPT
crr = self._get_crr(math.add(dptcirculation, token))
# Calculate the maximum price of DPT
dptprice = math.div(max_balance, math.mul(dptcirculation, crr))
# Actual price is equal to maximum price of DPT, for exchanging as less DPT to user as possible.
token = math.div(ethamount, dptprice)
# There could be less DPT remained in the DPT contract than supposed DPT, so contract need to issue new DPT
# the first situation is there is enough DPT
if math.sub(dptsupply, dptcirculation) >= token.real:
crr = self._get_crr(math.add(dptcirculation, token))
dptprice = math.div(max_balance,
math.mul(math.add(dptcirculation, token), crr))
return math.floattoether(token), 0, math.floattodecimal(
crr), math.floattodecimal(dptprice)
# the second situation is there is insufficient DPT in the contract
else:
# the maximum supposed token transfer from contract to user is determined by the remaining DPT in the contract.
# the issue price of token is
token = math.sub(dptsupply, dptcirculation)
# the minimum CRR after the deposit
crr = self._get_crr(math.add(dptcirculation, token))
# the maximum price after the deposit
dptprice = math.div(max_balance, math.mul(dptcirculation, crr))
return math.floattoether(token), math.floattoether(
math.sub(ethamount,
math.mul(token, dptprice))), math.floattodecimal(
crr), math.floattodecimal(dptprice)