Topic: [1500 TH] p2pool: Decentralized, DoS-resistant, Hop-Proof pool - page 317. (Read 2591971 times)

desired_pseudoshare_target = None
        desired_share_target = None
        for symbol, parameter in zip(contents2[::2], contents2[1::2]):
            if symbol == '+':
                try:
                    desired_pseudoshare_target = bitcoin_data.difficulty_to_target(float(parameter))
                except:
                    if p2pool.DEBUG:
                        log.err()
            elif symbol == '/':
                try:
                    desired_share_target = bitcoin_data.difficulty_to_target(float(parameter))
                except:
                    if p2pool.DEBUG:
                        log.err()

        if random.uniform(0, 100) < self.worker_fee:
            pubkey_hash = self.my_pubkey_hash
        else:
            try:
                pubkey_hash = bitcoin_data.address_to_pubkey_hash(user, self.node.net.PARENT)
            except: # XXX blah
                pubkey_hash = self.my_pubkey_hash

        return user, pubkey_hash, desired_share_target, desired_pseudoshare_target

def difficulty_to_target(difficulty):
    assert difficulty >= 0
    if difficulty == 0: return 2**256-1
    return min(int((0xffff0000 * 2**(256-64) + 1)/difficulty - 1 + 0.5), 2**256-1)

Python 2.7.8 (default, Jul  3 2014, 06:13:58) 
[GCC 4.2.1 Compatible Apple LLVM 5.1 (clang-503.0.40)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> x=2**256-1
>>> print x
115792089237316195423570985008687907853269984665640564039457584007913129639935
>>> exit()

if desired_share_target is None:
            desired_share_target = 2**256-1
            local_hash_rate = self._estimate_local_hash_rate()
            if local_hash_rate is not None:
                desired_share_target = min(desired_share_target,
                    bitcoin_data.average_attempts_to_target(local_hash_rate * self.node.net.SHARE_PERIOD / 0.0167)) # limit to 1.67% of pool shares by modulating share difficulty

            local_addr_rates = self.get_local_addr_rates()
            lookbehind = 3600//self.node.net.SHARE_PERIOD
            block_subsidy = self.node.bitcoind_work.value['subsidy']
            if previous_share is not None and self.node.tracker.get_height(previous_share.hash) > lookbehind:
                expected_payout_per_block = local_addr_rates.get(pubkey_hash, 0)/p2pool_data.get_pool_attempts_per_second(self.node.tracker, self.node.best_share_var.value, lookbehind) \
                    * block_subsidy*(1-self.donation_percentage/100) # XXX doesn't use global stale rate to compute pool hash
                if expected_payout_per_block < self.node.net.PARENT.DUST_THRESHOLD:
                    desired_share_target = min(desired_share_target,
                        bitcoin_data.average_attempts_to_target((bitcoin_data.target_to_average_attempts(self.node.bitcoind_work.value['bits'].target)*self.node.net.SPREAD)*self.node.net.PARENT.DUST_THRESHOLD/block_subsidy)
                    )