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Diffstat (limited to 'Godeps/_workspace/src/github.com/ethereum/serpent-go/serpent/examples/schellingcoin/schellingdollar.se')
| -rw-r--r-- | Godeps/_workspace/src/github.com/ethereum/serpent-go/serpent/examples/schellingcoin/schellingdollar.se | 171 |
1 files changed, 0 insertions, 171 deletions
diff --git a/Godeps/_workspace/src/github.com/ethereum/serpent-go/serpent/examples/schellingcoin/schellingdollar.se b/Godeps/_workspace/src/github.com/ethereum/serpent-go/serpent/examples/schellingcoin/schellingdollar.se deleted file mode 100644 index a34f42ce2..000000000 --- a/Godeps/_workspace/src/github.com/ethereum/serpent-go/serpent/examples/schellingcoin/schellingdollar.se +++ /dev/null @@ -1,171 +0,0 @@ -# Hedged zero-supply dollar implementation -# Uses SchellingCoin as price-determining backend -# -# Stored variables: -# -# 0: Schelling coin contract -# 1: Last epoch -# 2: Genesis block of contract -# 3: USD exposure -# 4: ETH exposure -# 5: Cached price -# 6: Last interest rate -# 2^160 + k: interest rate accumulator at k epochs -# 2^161 + ADDR * 3: eth-balance of a particular address -# 2^161 + ADDR * 3 + 1: usd-balance of a particular address -# 2^161 + ADDR * 3 + 1: last accessed epoch of a particular address -# -# Transaction types: -# -# [1, to, val]: send ETH -# [2, to, val]: send USD -# [3, wei_amount]: convert ETH to USD -# [4, usd_amount]: converts USD to ETH -# [5]: deposit -# [6, amount]: withdraw -# [7]: my balance query -# [7, acct]: balance query for any acct -# [8]: global state query -# [9]: liquidation test any account -# -# The purpose of the contract is to serve as a sort of cryptographic -# bank account where users can store both ETH and USD. ETH must be -# stored in zero or positive quantities, but USD balances can be -# positive or negative. If the USD balance is negative, the invariant -# usdbal * 10 >= ethbal * 9 must be satisfied; if any account falls -# below this value, then that account's balances are zeroed. Note -# that there is a 2% bounty to ping the app if an account does go -# below zero; one weakness is that if no one does ping then it is -# quite possible for accounts to go negative-net-worth, then zero -# themselves out, draining the reserves of the "bank" and potentially -# bankrupting it. A 0.1% fee on ETH <-> USD trade is charged to -# minimize this risk. Additionally, the bank itself will inevitably -# end up with positive or negative USD exposure; to mitigate this, -# it automatically updates interest rates on USD to keep exposure -# near zero. - -data schelling_coin -data last_epoch -data starting_block -data usd_exposure -data eth_exposure -data price -data last_interest_rate -data interest_rate_accum[2^50] -data accounts[2^160](eth, usd, last_epoch) - -extern sc: [submit_hash, submit_value, request_balance, request_output] - -def init(): - self.schelling_coin = create('schellingcoin.se') - self.price = self.schelling_coin.request_output() - self.interest_rate_accum[0] = 10^18 - self.starting_block = block.number - -def any(): - sender = msg.sender - epoch = (block.number - self.starting_block) / 100 - last_epoch = self.last_epoch - usdprice = self.price - - # Update contract epochs - if epoch > last_epoch: - delta = epoch - last_epoch - last_interest_rate = self.last_interest_rate - usd_exposure - self.usd_exposure - last_accum = self.interest_rate_accum[last_epoch] - - if usd_exposure < 0: - self.last_interest_rate = last_interest_rate - 10000 * delta - elif usd_exposure > 0: - self.last_interest_rate = last_interest_rate + 10000 * delta - - self.interest_rate_accum[epoch] = last_accum + last_accum * last_interest_rate * delta / 10^9 - - # Proceeds go to support the SchellingCoin feeding it price data, ultimately providing the depositors - # of the SchellingCoin an interest rate - bal = max(self.balance - self.eth_exposure, 0) / 10000 - usdprice = self.schelling_coin.request_output() - self.price = usdprice - self.last_epoch = epoch - - ethbal = self.accounts[msg.sender].eth - usdbal = self.accounts[msg.sender].usd - - # Apply interest rates to sender and liquidation-test self - if msg.sender != self: - self.ping(self) - -def send_eth(to, value): - if value > 0 and value <= ethbal and usdbal * usdprice * 2 + (ethbal - value) >= 0: - self.accounts[msg.sender].eth = ethbal - value - self.ping(to) - self.accounts[to].eth += value - return(1) - -def send_usd(to, value): - if value > 0 and value <= usdbal and (usdbal - value) * usdprice * 2 + ethbal >= 0: - self.accounts[msg.sender].usd = usdbal - value - self.ping(to) - self.accounts[to].usd += value - return(1) - -def convert_to_eth(usdvalue): - ethplus = usdvalue * usdprice * 999 / 1000 - if usdvalue > 0 and (usdbal - usdvalue) * usdprice * 2 + (ethbal + ethplus) >= 0: - self.accounts[msg.sender].eth = ethbal + ethplus - self.accounts[msg.sender].usd = usdbal - usdvalue - self.eth_exposure += ethplus - self.usd_exposure -= usdvalue - return([ethbal + ethplus, usdbal - usdvalue], 2) - -def convert_to_usd(ethvalue): - usdplus = ethvalue / usdprice * 999 / 1000 - if ethvalue > 0 and (usdbal + usdplus) * usdprice * 2 + (ethbal - ethvalue) >= 0: - self.accounts[msg.sender].eth = ethbal - ethvalue - self.accounts[msg.sender].usd = usdbal + usdplus - self.eth_exposure -= ethvalue - self.usd_exposure += usdplus - return([ethbal - ethvalue, usdbal + usdplus], 2) - -def deposit(): - self.accounts[msg.sender].eth = ethbal + msg.value - self.eth_exposure += msg.value - return(ethbal + msg.value) - -def withdraw(value): - if value > 0 and value <= ethbal and usdbal * usdprice * 2 + (ethbal - value) >= 0: - self.accounts[msg.sender].eth -= value - self.eth_exposure -= value - return(ethbal - value) - -def balance(acct): - self.ping(acct) - return([self.accounts[acct].eth, self.accounts[acct].usd], 2) - -def global_state_query(acct): - interest = self.last_interest_rate - usd_exposure = self.usd_exposure - eth_exposure = self.eth_exposure - eth_balance = self.balance - return([epoch, usdprice, interest, usd_exposure, eth_exposure, eth_balance], 6) - -def ping(acct): - account_last_epoch = self.accounts[acct].last_epoch - if account_last_epoch != epoch: - cur_usd_balance = self.accounts[acct].usd - new_usd_balance = cur_usd_balance * self.interest_rate_accum[epoch] / self.interest_rate_accum[account_last_epoch] - self.accounts[acct].usd = new_usd_balance - self.accounts[acct].last_epoch = epoch - self.usd_exposure += new_usd_balance - cur_usd_balance - - ethbal = self.accounts[acct].eth - - if new_usd_balance * usdval * 10 + ethbal * 9 < 0: - self.accounts[acct].eth = 0 - self.accounts[acct].usd = 0 - self.accounts[msg.sender].eth += ethbal / 50 - self.eth_exposure += -ethbal + ethbal / 50 - self.usd_exposure += new_usd_balance - return(1) - return(0) |