X-Git-Url: https://git.novaco.in/?a=blobdiff_plain;f=p2pool%2Fdata.py;h=83c1cdc42f2a6fb8b280390f4a18563629330bc8;hb=76b297b65cd33bf972b00820b635b993f28e8133;hp=58cb3d63d693adbf064f3bd4d339222be1b2b5ef;hpb=2073539b6f7355bea0151b2cf91deecfcc05f937;p=p2pool.git diff --git a/p2pool/data.py b/p2pool/data.py index 58cb3d6..83c1cdc 100644 --- a/p2pool/data.py +++ b/p2pool/data.py @@ -39,23 +39,25 @@ share_type = pack.ComposedType([ ('contents', pack.VarStrType()), ]) -def load_share(share, net, peer): - if share['type'] in [0, 1, 2, 3, 4, 5, 6, 7, 8]: +def load_share(share, net, peer_addr): + assert peer_addr is None or isinstance(peer_addr, tuple) + if share['type'] < Share.VERSION: from p2pool import p2p raise p2p.PeerMisbehavingError('sent an obsolete share') elif share['type'] == Share.VERSION: - return Share(net, peer, Share.share_type.unpack(share['contents'])) + return Share(net, peer_addr, Share.share_type.unpack(share['contents'])) + elif share['type'] == NewShare.VERSION: + return NewShare(net, peer_addr, NewShare.share_type.unpack(share['contents'])) else: raise ValueError('unknown share type: %r' % (share['type'],)) DONATION_SCRIPT = '4104ffd03de44a6e11b9917f3a29f9443283d9871c9d743ef30d5eddcd37094b64d1b3d8090496b53256786bf5c82932ec23c3b74d9f05a6f95a8b5529352656664bac'.decode('hex') -class Share(object): - VERSION = 9 +class NewShare(object): + VERSION = 13 + VOTING_VERSION = 13 SUCCESSOR = None - other_txs = None - small_block_header_type = pack.ComposedType([ ('version', pack.VarIntType()), ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))), @@ -121,8 +123,42 @@ class Share(object): max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3) bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//10, pre_target3))) - weights, total_weight, donation_weight = tracker.get_cumulative_weights(share_data['previous_share_hash'], - min(height, net.REAL_CHAIN_LENGTH), + new_transaction_hashes = [] + new_transaction_size = 0 + transaction_hash_refs = [] + other_transaction_hashes = [] + + past_shares = list(tracker.get_chain(share_data['previous_share_hash'], min(height, 100))) + tx_hash_to_this = {} + for i, share in enumerate(past_shares): + for j, tx_hash in enumerate(share.new_transaction_hashes): + if tx_hash not in tx_hash_to_this: + tx_hash_to_this[tx_hash] = [1+i, j] # share_count, tx_count + for tx_hash, fee in desired_other_transaction_hashes_and_fees: + if tx_hash in tx_hash_to_this: + this = tx_hash_to_this[tx_hash] + else: + if known_txs is not None: + this_size = bitcoin_data.tx_type.packed_size(known_txs[tx_hash]) + if new_transaction_size + this_size > 50000: # only allow 50 kB of new txns/share + break + new_transaction_size += this_size + new_transaction_hashes.append(tx_hash) + this = [0, len(new_transaction_hashes)-1] + transaction_hash_refs.extend(this) + other_transaction_hashes.append(tx_hash) + + included_transactions = set(other_transaction_hashes) + removed_fees = [fee for tx_hash, fee in desired_other_transaction_hashes_and_fees if tx_hash not in included_transactions] + definite_fees = sum(0 if fee is None else fee for tx_hash, fee in desired_other_transaction_hashes_and_fees if tx_hash in included_transactions) + if None not in removed_fees: + share_data = dict(share_data, subsidy=share_data['subsidy'] - sum(removed_fees)) + else: + assert base_subsidy is not None + share_data = dict(share_data, subsidy=base_subsidy + definite_fees) + + weights, total_weight, donation_weight = tracker.get_cumulative_weights(previous_share.share_data['previous_share_hash'] if previous_share is not None else None, + min(height, net.REAL_CHAIN_LENGTH-1), 65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target), ) assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight) @@ -137,6 +173,271 @@ class Share(object): dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit + share_info = dict( + share_data=share_data, + far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99), + max_bits=max_bits, + bits=bits, + timestamp=math.clip(desired_timestamp, ( + (previous_share.timestamp + net.SHARE_PERIOD) - (net.SHARE_PERIOD - 1), # = previous_share.timestamp + 1 + (previous_share.timestamp + net.SHARE_PERIOD) + (net.SHARE_PERIOD - 1), + )) if previous_share is not None else desired_timestamp, + new_transaction_hashes=new_transaction_hashes, + transaction_hash_refs=transaction_hash_refs, + ) + + gentx = dict( + version=1, + tx_ins=[dict( + previous_output=None, + sequence=None, + script=share_data['coinbase'], + )], + tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT] + [dict( + value=0, + script='\x24' + cls.get_ref_hash(net, share_info, ref_merkle_link) + pack.IntType(32).pack(last_txout_nonce), + )], + lock_time=0, + ) + + def get_share(header, last_txout_nonce=last_txout_nonce): + min_header = dict(header); del min_header['merkle_root'] + share = cls(net, None, dict( + min_header=min_header, + share_info=share_info, + ref_merkle_link=dict(branch=[], index=0), + last_txout_nonce=last_txout_nonce, + hash_link=prefix_to_hash_link(bitcoin_data.tx_type.pack(gentx)[:-32-4-4], cls.gentx_before_refhash), + merkle_link=bitcoin_data.calculate_merkle_link([None] + other_transaction_hashes, 0), + )) + assert share.header == header # checks merkle_root + return share + + return share_info, gentx, other_transaction_hashes, get_share + + @classmethod + def get_ref_hash(cls, net, share_info, ref_merkle_link): + return pack.IntType(256).pack(bitcoin_data.check_merkle_link(bitcoin_data.hash256(cls.ref_type.pack(dict( + identifier=net.IDENTIFIER, + share_info=share_info, + ))), ref_merkle_link)) + + __slots__ = 'net peer_addr contents min_header share_info hash_link merkle_link hash share_data max_target target timestamp previous_hash new_script desired_version gentx_hash header pow_hash header_hash new_transaction_hashes time_seen'.split(' ') + + def __init__(self, net, peer_addr, contents): + self.net = net + self.peer_addr = peer_addr + self.contents = contents + + self.min_header = contents['min_header'] + self.share_info = contents['share_info'] + self.hash_link = contents['hash_link'] + self.merkle_link = contents['merkle_link'] + + if not (2 <= len(self.share_info['share_data']['coinbase']) <= 100): + raise ValueError('''bad coinbase size! %i bytes''' % (len(self.share_info['share_data']['coinbase']),)) + + if len(self.merkle_link['branch']) > 16: + raise ValueError('merkle branch too long!') + + assert not self.hash_link['extra_data'], repr(self.hash_link['extra_data']) + + self.share_data = self.share_info['share_data'] + self.max_target = self.share_info['max_bits'].target + self.target = self.share_info['bits'].target + self.timestamp = self.share_info['timestamp'] + self.previous_hash = self.share_data['previous_share_hash'] + self.new_script = bitcoin_data.pubkey_hash_to_script2(self.share_data['pubkey_hash']) + self.desired_version = self.share_data['desired_version'] + + n = set() + for share_count, tx_count in self.iter_transaction_hash_refs(): + assert share_count < 110 + if share_count == 0: + n.add(tx_count) + assert n == set(range(len(self.share_info['new_transaction_hashes']))) + + self.gentx_hash = check_hash_link( + self.hash_link, + self.get_ref_hash(net, self.share_info, contents['ref_merkle_link']) + pack.IntType(32).pack(self.contents['last_txout_nonce']) + pack.IntType(32).pack(0), + self.gentx_before_refhash, + ) + merkle_root = bitcoin_data.check_merkle_link(self.gentx_hash, self.merkle_link) + self.header = dict(self.min_header, merkle_root=merkle_root) + self.pow_hash = net.PARENT.POW_FUNC(bitcoin_data.block_header_type.pack(self.header)) + self.hash = self.header_hash = bitcoin_data.hash256(bitcoin_data.block_header_type.pack(self.header)) + + if self.target > net.MAX_TARGET: + from p2pool import p2p + raise p2p.PeerMisbehavingError('share target invalid') + + if self.pow_hash > self.target: + from p2pool import p2p + raise p2p.PeerMisbehavingError('share PoW invalid') + + self.new_transaction_hashes = self.share_info['new_transaction_hashes'] + + # XXX eww + self.time_seen = time.time() + + def __repr__(self): + return 'Share' + repr((self.net, self.peer_addr, self.contents)) + + def as_share(self): + return dict(type=self.VERSION, contents=self.share_type.pack(self.contents)) + + def iter_transaction_hash_refs(self): + return zip(self.share_info['transaction_hash_refs'][::2], self.share_info['transaction_hash_refs'][1::2]) + + def check(self, tracker): + from p2pool import p2p + if self.share_data['previous_share_hash'] is not None: + previous_share = tracker.items[self.share_data['previous_share_hash']] + if type(self) is type(previous_share): + pass + elif type(self) is type(previous_share).SUCCESSOR: + if tracker.get_height(previous_share.hash) < self.net.CHAIN_LENGTH: + from p2pool import p2p + raise p2p.PeerMisbehavingError('switch without enough history') + + # switch only valid if 85% of hashes in [self.net.CHAIN_LENGTH*9//10, self.net.CHAIN_LENGTH] for new version + counts = get_desired_version_counts(tracker, + tracker.get_nth_parent_hash(previous_share.hash, self.net.CHAIN_LENGTH*9//10), self.net.CHAIN_LENGTH//10) + if counts.get(self.VERSION, 0) < sum(counts.itervalues())*85//100: + raise p2p.PeerMisbehavingError('switch without enough hash power upgraded') + else: + raise p2p.PeerMisbehavingError('''%s can't follow %s''' % (type(self).__name__, type(previous_share).__name__)) + + other_tx_hashes = [tracker.items[tracker.get_nth_parent_hash(self.hash, share_count)].share_info['new_transaction_hashes'][tx_count] for share_count, tx_count in self.iter_transaction_hash_refs()] + + share_info, gentx, other_tx_hashes2, get_share = self.generate_transaction(tracker, self.share_info['share_data'], self.header['bits'].target, self.share_info['timestamp'], self.share_info['bits'].target, self.contents['ref_merkle_link'], [(h, None) for h in other_tx_hashes], self.net, last_txout_nonce=self.contents['last_txout_nonce']) + assert other_tx_hashes2 == other_tx_hashes + if share_info != self.share_info: + raise ValueError('share_info invalid') + if bitcoin_data.hash256(bitcoin_data.tx_type.pack(gentx)) != self.gentx_hash: + raise ValueError('''gentx doesn't match hash_link''') + + if bitcoin_data.calculate_merkle_link([None] + other_tx_hashes, 0) != self.merkle_link: + raise ValueError('merkle_link and other_tx_hashes do not match') + + return gentx # only used by as_block + + def get_other_tx_hashes(self, tracker): + parents_needed = max(share_count for share_count, tx_count in self.iter_transaction_hash_refs()) if self.share_info['transaction_hash_refs'] else 0 + parents = tracker.get_height(self.hash) - 1 + if parents < parents_needed: + return None + last_shares = list(tracker.get_chain(self.hash, parents_needed + 1)) + return [last_shares[share_count].share_info['new_transaction_hashes'][tx_count] for share_count, tx_count in self.iter_transaction_hash_refs()] + + def _get_other_txs(self, tracker, known_txs): + other_tx_hashes = self.get_other_tx_hashes(tracker) + if other_tx_hashes is None: + return None # not all parents present + + if not all(tx_hash in known_txs for tx_hash in other_tx_hashes): + return None # not all txs present + + return [known_txs[tx_hash] for tx_hash in other_tx_hashes] + + def should_punish_reason(self, previous_block, bits, tracker, known_txs): + if (self.header['previous_block'], self.header['bits']) != (previous_block, bits) and self.header_hash != previous_block and self.peer_addr is not None: + return True, 'Block-stale detected! %x < %x' % (self.header['previous_block'], previous_block) + + if self.pow_hash <= self.header['bits'].target: + return -1, 'block solution' + + other_txs = self._get_other_txs(tracker, known_txs) + if other_txs is None: + if self.time_seen != 0: # ignore if loaded from ShareStore + return True, 'not all txs present' + else: + all_txs_size = sum(bitcoin_data.tx_type.packed_size(tx) for tx in other_txs) + if all_txs_size > 1000000: + return True, 'txs over block size limit' + + new_txs_size = sum(bitcoin_data.tx_type.packed_size(known_txs[tx_hash]) for tx_hash in self.share_info['new_transaction_hashes']) + if new_txs_size > 50000: + return True, 'new txs over limit' + + return False, None + + def as_block(self, tracker, known_txs): + other_txs = self._get_other_txs(tracker, known_txs) + if other_txs is None: + return None # not all txs present + return dict(header=self.header, txs=[self.check(tracker)] + other_txs) + +class Share(object): + VERSION = 9 + VOTING_VERSION = 11 + SUCCESSOR = NewShare + + small_block_header_type = pack.ComposedType([ + ('version', pack.VarIntType()), + ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))), + ('timestamp', pack.IntType(32)), + ('bits', bitcoin_data.FloatingIntegerType()), + ('nonce', pack.IntType(32)), + ]) + + share_info_type = pack.ComposedType([ + ('share_data', pack.ComposedType([ + ('previous_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))), + ('coinbase', pack.VarStrType()), + ('nonce', pack.IntType(32)), + ('pubkey_hash', pack.IntType(160)), + ('subsidy', pack.IntType(64)), + ('donation', pack.IntType(16)), + ('stale_info', pack.EnumType(pack.IntType(8), dict((k, {0: None, 253: 'orphan', 254: 'doa'}.get(k, 'unk%i' % (k,))) for k in xrange(256)))), + ('desired_version', pack.VarIntType()), + ])), + ('new_transaction_hashes', pack.ListType(pack.IntType(256))), + ('transaction_hash_refs', pack.ListType(pack.VarIntType(), 2)), # pairs of share_count, tx_count + ('far_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))), + ('max_bits', bitcoin_data.FloatingIntegerType()), + ('bits', bitcoin_data.FloatingIntegerType()), + ('timestamp', pack.IntType(32)), + ]) + + share_type = pack.ComposedType([ + ('min_header', small_block_header_type), + ('share_info', share_info_type), + ('ref_merkle_link', pack.ComposedType([ + ('branch', pack.ListType(pack.IntType(256))), + ('index', pack.IntType(0)), + ])), + ('last_txout_nonce', pack.IntType(32)), + ('hash_link', hash_link_type), + ('merkle_link', pack.ComposedType([ + ('branch', pack.ListType(pack.IntType(256))), + ('index', pack.IntType(0)), # it will always be 0 + ])), + ]) + + ref_type = pack.ComposedType([ + ('identifier', pack.FixedStrType(64//8)), + ('share_info', share_info_type), + ]) + + gentx_before_refhash = pack.VarStrType().pack(DONATION_SCRIPT) + pack.IntType(64).pack(0) + pack.VarStrType().pack('\x24' + pack.IntType(256).pack(0) + pack.IntType(32).pack(0))[:2] + + @classmethod + def generate_transaction(cls, tracker, share_data, block_target, desired_timestamp, desired_target, ref_merkle_link, desired_other_transaction_hashes_and_fees, net, known_txs=None, last_txout_nonce=0, base_subsidy=None): + previous_share = tracker.items[share_data['previous_share_hash']] if share_data['previous_share_hash'] is not None else None + + height, last = tracker.get_height_and_last(share_data['previous_share_hash']) + assert height >= net.REAL_CHAIN_LENGTH or last is None + if height < net.TARGET_LOOKBEHIND: + pre_target3 = net.MAX_TARGET + else: + attempts_per_second = get_pool_attempts_per_second(tracker, share_data['previous_share_hash'], net.TARGET_LOOKBEHIND, min_work=True, integer=True) + pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1 if attempts_per_second else 2**256-1 + pre_target2 = math.clip(pre_target, (previous_share.max_target*9//10, previous_share.max_target*11//10)) + pre_target3 = math.clip(pre_target2, (net.MIN_TARGET, net.MAX_TARGET)) + max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3) + bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//10, pre_target3))) + new_transaction_hashes = [] new_transaction_size = 0 transaction_hash_refs = [] @@ -171,6 +472,22 @@ class Share(object): assert base_subsidy is not None share_data = dict(share_data, subsidy=base_subsidy + definite_fees) + weights, total_weight, donation_weight = tracker.get_cumulative_weights(share_data['previous_share_hash'], + min(height, net.REAL_CHAIN_LENGTH), + 65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target), + ) + assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight) + + amounts = dict((script, share_data['subsidy']*(199*weight)//(200*total_weight)) for script, weight in weights.iteritems()) # 99.5% goes according to weights prior to this share + this_script = bitcoin_data.pubkey_hash_to_script2(share_data['pubkey_hash']) + amounts[this_script] = amounts.get(this_script, 0) + share_data['subsidy']//200 # 0.5% goes to block finder + amounts[DONATION_SCRIPT] = amounts.get(DONATION_SCRIPT, 0) + share_data['subsidy'] - sum(amounts.itervalues()) # all that's left over is the donation weight and some extra satoshis due to rounding + + if sum(amounts.itervalues()) != share_data['subsidy'] or any(x < 0 for x in amounts.itervalues()): + raise ValueError() + + dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit + share_info = dict( share_data=share_data, far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99), @@ -220,11 +537,11 @@ class Share(object): share_info=share_info, ))), ref_merkle_link)) - __slots__ = 'net peer contents min_header share_info hash_link merkle_link hash share_data max_target target timestamp previous_hash new_script desired_version gentx_hash header pow_hash header_hash new_transaction_hashes time_seen'.split(' ') + __slots__ = 'net peer_addr contents min_header share_info hash_link merkle_link hash share_data max_target target timestamp previous_hash new_script desired_version gentx_hash header pow_hash header_hash new_transaction_hashes time_seen'.split(' ') - def __init__(self, net, peer, contents): + def __init__(self, net, peer_addr, contents): self.net = net - self.peer = peer + self.peer_addr = peer_addr self.contents = contents self.min_header = contents['min_header'] @@ -279,7 +596,7 @@ class Share(object): self.time_seen = time.time() def __repr__(self): - return 'Share' + repr((self.net, self.peer, self.contents)) + return 'Share' + repr((self.net, self.peer_addr, self.contents)) def as_share(self): return dict(type=self.VERSION, contents=self.share_type.pack(self.contents)) @@ -339,7 +656,7 @@ class Share(object): return [known_txs[tx_hash] for tx_hash in other_tx_hashes] def should_punish_reason(self, previous_block, bits, tracker, known_txs): - if (self.header['previous_block'], self.header['bits']) != (previous_block, bits) and self.header_hash != previous_block and self.peer is not None: + if (self.header['previous_block'], self.header['bits']) != (previous_block, bits) and self.header_hash != previous_block and self.peer_addr is not None: return True, 'Block-stale detected! %x < %x' % (self.header['previous_block'], previous_block) if self.pow_hash <= self.header['bits'].target: @@ -367,6 +684,7 @@ class Share(object): return dict(header=self.header, txs=[self.check(tracker)] + other_txs) + class WeightsSkipList(forest.TrackerSkipList): # share_count, weights, total_weight @@ -451,7 +769,7 @@ class OkayTracker(forest.Tracker): else: if last is not None: desired.add(( - self.items[random.choice(list(self.reverse[last]))].peer, + self.items[random.choice(list(self.reverse[last]))].peer_addr, last, max(x.timestamp for x in self.get_chain(head, min(head_height, 5))), min(x.target for x in self.get_chain(head, min(head_height, 5))), @@ -477,7 +795,7 @@ class OkayTracker(forest.Tracker): break if head_height < self.net.CHAIN_LENGTH and last_last_hash is not None: desired.add(( - self.items[random.choice(list(self.verified.reverse[last_hash]))].peer, + self.items[random.choice(list(self.verified.reverse[last_hash]))].peer_addr, last_last_hash, max(x.timestamp for x in self.get_chain(head, min(head_height, 5))), min(x.target for x in self.get_chain(head, min(head_height, 5))), @@ -494,7 +812,7 @@ class OkayTracker(forest.Tracker): # decide best verified head decorated_heads = sorted((( self.verified.get_work(self.verified.get_nth_parent_hash(h, min(5, self.verified.get_height(h)))), - #self.items[h].peer is None, + #self.items[h].peer_addr is None, -self.items[h].should_punish_reason(previous_block, bits, self, known_txs)[0], -self.items[h].time_seen, ), h) for h in self.verified.tails.get(best_tail, [])) @@ -512,17 +830,17 @@ class OkayTracker(forest.Tracker): best = best_share.previous_hash timestamp_cutoff = min(int(time.time()), best_share.timestamp) - 3600 - target_cutoff = 2**256//(self.net.SHARE_PERIOD*best_tail_score[1] + 1) * 2 if best_tail_score[1] is not None else 2**256-1 + target_cutoff = int(2**256//(self.net.SHARE_PERIOD*best_tail_score[1] + 1) * 2 + .5) if best_tail_score[1] is not None else 2**256-1 else: timestamp_cutoff = int(time.time()) - 24*60*60 target_cutoff = 2**256-1 if p2pool.DEBUG: print 'Desire %i shares. Cutoff: %s old diff>%.2f' % (len(desired), math.format_dt(time.time() - timestamp_cutoff), bitcoin_data.target_to_difficulty(target_cutoff)) - for peer, hash, ts, targ in desired: - print ' ', '%s:%i' % peer.addr if peer is not None else None, format_hash(hash), math.format_dt(time.time() - ts), bitcoin_data.target_to_difficulty(targ), ts >= timestamp_cutoff, targ <= target_cutoff + for peer_addr, hash, ts, targ in desired: + print ' ', None if peer_addr is None else '%s:%i' % peer_addr, format_hash(hash), math.format_dt(time.time() - ts), bitcoin_data.target_to_difficulty(targ), ts >= timestamp_cutoff, targ <= target_cutoff - return best, [(peer, hash) for peer, hash, ts, targ in desired if ts >= timestamp_cutoff], decorated_heads + return best, [(peer_addr, hash) for peer_addr, hash, ts, targ in desired if ts >= timestamp_cutoff], decorated_heads def score(self, share_hash, block_rel_height_func): # returns approximate lower bound on chain's hashrate in the last self.net.CHAIN_LENGTH*15//16*self.net.SHARE_PERIOD time @@ -595,7 +913,7 @@ def get_warnings(tracker, best_share, net, bitcoind_warning, bitcoind_work_value desired_version_counts = get_desired_version_counts(tracker, best_share, min(net.CHAIN_LENGTH, 60*60//net.SHARE_PERIOD, tracker.get_height(best_share))) majority_desired_version = max(desired_version_counts, key=lambda k: desired_version_counts[k]) - if majority_desired_version > 10 and desired_version_counts[majority_desired_version] > sum(desired_version_counts.itervalues())/2: + if majority_desired_version > (Share.SUCCESSOR if Share.SUCCESSOR is not None else Share).VOTING_VERSION and desired_version_counts[majority_desired_version] > sum(desired_version_counts.itervalues())/2: res.append('A MAJORITY OF SHARES CONTAIN A VOTE FOR AN UNSUPPORTED SHARE IMPLEMENTATION! (v%i with %i%% support)\n' 'An upgrade is likely necessary. Check http://p2pool.forre.st/ for more information.' % ( majority_desired_version, 100*desired_version_counts[majority_desired_version]/sum(desired_version_counts.itervalues())))