def start_bank_process(self, readTokens, writeTokens, paymentId):
"""Create the bank message, and send it to the payment proxy for relaying to the bank.
@param readTokens: how many read tokens to pay the merchant for
@type readTokens: int
@param writeTokens: how many write tokens to pay the merchant for
@type writeTokens: int
@param paymentId: the id for this payment, for tracking when it is completed
@type paymentId: int
"""
#generate the response message:
msg = Basic.write_byte(PAR_VERSION)
msg += Basic.write_int(readTokens)
msg += Basic.write_int(writeTokens)
msg += Basic.write_long(paymentId)
#figure out how many payments must be made:
totalTokens = readTokens + writeTokens
numPayments = totalTokens / Globals.CELLS_PER_PAYMENT
msg += Basic.write_byte(numPayments)
bankMsg = Basic.write_byte(numPayments)
for i in range(0, numPayments):
#get a token to use for this payment:
requestId, token = self.paymentTokens.popitem()
#send it to the bank for signing
coin = self.parClient.bank.get_acoins(1)
if not coin:
paymentDeferred = self.paymentDeferreds[paymentId]
del self.paymentDeferreds[paymentId]
paymentDeferred.errback(InsufficientACoins("No ACoins left."))
return
coin = coin[0]
self.parClient.circ.app.coinsSpent += 1
# log_msg("Srsly, wtf is going on? %s" % (coin.interval), 4)
bankMsg += coin.write_binary() + token
msg += Basic.write_byte(COIN_TYPES['A']) + Basic.write_long(requestId)
key = EncryptedDatagram.ClientSymKey(self.parClient.bank.PUBLIC_KEY)
bankMsg = Basic.write_byte(1) + key.encrypt(Basic.write_byte(3) + bankMsg)
msg = Basic.write_byte(PAR_VERSION) + Basic.write_byte(self.hop-1) + Basic.write_lenstr(bankMsg) + Basic.write_lenstr(msg)
self.parClient.send_direct_tor_message(msg, "bank_relay", True, self.paymentProxyHop)
