p2pool/data.py

   1 from __future__ import division
   2
   3 import hashlib
   4 import os
   5 import random
   6 import sys
   7 import time
   8
   9 from twisted.python import log
  10
  11 import p2pool
  12 from p2pool.bitcoin import data as bitcoin_data, script, sha256
  13 from p2pool.util import math, forest, pack
  14
  15 # hashlink
  16
  17 hash_link_type = pack.ComposedType([
  18     ('state', pack.FixedStrType(32)),
  19     ('extra_data', pack.FixedStrType(0)), # bit of a hack, but since the donation script is at the end, const_ending is long enough to always make this empty
  20     ('length', pack.VarIntType()),
  21 ])
  22
  23 def prefix_to_hash_link(prefix, const_ending=''):
  24     assert prefix.endswith(const_ending), (prefix, const_ending)
  25     x = sha256.sha256(prefix)
  26     return dict(state=x.state, extra_data=x.buf[:max(0, len(x.buf)-len(const_ending))], length=x.length//8)
  27
  28 def check_hash_link(hash_link, data, const_ending=''):
  29     extra_length = hash_link['length'] % (512//8)
  30     assert len(hash_link['extra_data']) == max(0, extra_length - len(const_ending))
  31     extra = (hash_link['extra_data'] + const_ending)[len(hash_link['extra_data']) + len(const_ending) - extra_length:]
  32     assert len(extra) == extra_length
  33     return pack.IntType(256).unpack(hashlib.sha256(sha256.sha256(data, (hash_link['state'], extra, 8*hash_link['length'])).digest()).digest())
  34
  35 # shares
  36
  37 share_type = pack.ComposedType([
  38     ('type', pack.VarIntType()),
  39     ('contents', pack.VarStrType()),
  40 ])
  41
  42 def load_share(share, net, peer_addr):
  43     assert peer_addr is None or isinstance(peer_addr, tuple)
  44     if share['type'] < Share.VERSION:
  45         from p2pool import p2p
  46         raise p2p.PeerMisbehavingError('sent an obsolete share')
  47     elif share['type'] == Share.VERSION:
  48         return Share(net, peer_addr, Share.share_type.unpack(share['contents']))
  49     else:
  50         raise ValueError('unknown share type: %r' % (share['type'],))
  51
  52 DONATION_SCRIPT = bitcoin_data.pubkey_hash_to_script2(1242320440330127026527917315978635769218557336395)
  53
  54 class Share(object):
  55     VERSION = 13
  56     VOTING_VERSION = 13
  57     SUCCESSOR = None
  58
  59     small_block_header_type = pack.ComposedType([
  60         ('version', pack.VarIntType()),
  61         ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))),
  62         ('timestamp', pack.IntType(32)),
  63         ('bits', bitcoin_data.FloatingIntegerType()),
  64         ('nonce', pack.IntType(32)),
  65     ])
  66
  67     share_info_type = pack.ComposedType([
  68         ('share_data', pack.ComposedType([
  69             ('previous_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
  70             ('coinbase', pack.VarStrType()),
  71             ('nonce', pack.IntType(32)),
  72             ('pubkey_hash', pack.IntType(160)),
  73             ('subsidy', pack.IntType(64)),
  74             ('donation', pack.IntType(16)),
  75             ('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)))),
  76             ('desired_version', pack.VarIntType()),
  77         ])),
  78         ('new_transaction_hashes', pack.ListType(pack.IntType(256))),
  79         ('transaction_hash_refs', pack.ListType(pack.VarIntType(), 2)), # pairs of share_count, tx_count
  80         ('far_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
  81         ('max_bits', bitcoin_data.FloatingIntegerType()),
  82         ('bits', bitcoin_data.FloatingIntegerType()),
  83         ('timestamp', pack.IntType(32)),
  84         ('absheight', pack.IntType(32)),
  85         ('abswork', pack.IntType(128)),
  86     ])
  87
  88     share_type = pack.ComposedType([
  89         ('min_header', small_block_header_type),
  90         ('share_info', share_info_type),
  91         ('ref_merkle_link', pack.ComposedType([
  92             ('branch', pack.ListType(pack.IntType(256))),
  93             ('index', pack.IntType(0)),
  94         ])),
  95         ('last_txout_nonce', pack.IntType(64)),
  96         ('hash_link', hash_link_type),
  97         ('merkle_link', pack.ComposedType([
  98             ('branch', pack.ListType(pack.IntType(256))),
  99             ('index', pack.IntType(0)), # it will always be 0
 100         ])),
 101     ])
 102
 103     ref_type = pack.ComposedType([
 104         ('identifier', pack.FixedStrType(64//8)),
 105         ('share_info', share_info_type),
 106     ])
 107
 108     gentx_before_refhash = pack.VarStrType().pack(DONATION_SCRIPT) + pack.IntType(64).pack(0) + pack.VarStrType().pack('\x6a\x28' + pack.IntType(256).pack(0) + pack.IntType(64).pack(0))[:3]
 109
 110     @classmethod
 111     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):
 112         previous_share = tracker.items[share_data['previous_share_hash']] if share_data['previous_share_hash'] is not None else None
 113
 114         height, last = tracker.get_height_and_last(share_data['previous_share_hash'])
 115         assert height >= net.REAL_CHAIN_LENGTH or last is None
 116         if height < net.TARGET_LOOKBEHIND:
 117             pre_target3 = net.MAX_TARGET
 118         else:
 119             attempts_per_second = get_pool_attempts_per_second(tracker, share_data['previous_share_hash'], net.TARGET_LOOKBEHIND, min_work=True, integer=True)
 120             pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1 if attempts_per_second else 2**256-1
 121             pre_target2 = math.clip(pre_target, (previous_share.max_target*9//10, previous_share.max_target*11//10))
 122             pre_target3 = math.clip(pre_target2, (net.MIN_TARGET, net.MAX_TARGET))
 123         max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
 124         bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//30, pre_target3)))
 125
 126         new_transaction_hashes = []
 127         new_transaction_size = 0
 128         transaction_hash_refs = []
 129         other_transaction_hashes = []
 130
 131         past_shares = list(tracker.get_chain(share_data['previous_share_hash'], min(height, 100)))
 132         tx_hash_to_this = {}
 133         for i, share in enumerate(past_shares):
 134             for j, tx_hash in enumerate(share.new_transaction_hashes):
 135                 if tx_hash not in tx_hash_to_this:
 136                     tx_hash_to_this[tx_hash] = [1+i, j] # share_count, tx_count
 137         for tx_hash, fee in desired_other_transaction_hashes_and_fees:
 138             if tx_hash in tx_hash_to_this:
 139                 this = tx_hash_to_this[tx_hash]
 140             else:
 141                 if known_txs is not None:
 142                     this_size = bitcoin_data.tx_type.packed_size(known_txs[tx_hash])
 143                     if new_transaction_size + this_size > 50000: # only allow 50 kB of new txns/share
 144                         break
 145                     new_transaction_size += this_size
 146                 new_transaction_hashes.append(tx_hash)
 147                 this = [0, len(new_transaction_hashes)-1]
 148             transaction_hash_refs.extend(this)
 149             other_transaction_hashes.append(tx_hash)
 150
 151         included_transactions = set(other_transaction_hashes)
 152         removed_fees = [fee for tx_hash, fee in desired_other_transaction_hashes_and_fees if tx_hash not in included_transactions]
 153         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)
 154         if None not in removed_fees:
 155             share_data = dict(share_data, subsidy=share_data['subsidy'] - sum(removed_fees))
 156         else:
 157             assert base_subsidy is not None
 158             share_data = dict(share_data, subsidy=base_subsidy + definite_fees)
 159
 160         weights, total_weight, donation_weight = tracker.get_cumulative_weights(previous_share.share_data['previous_share_hash'] if previous_share is not None else None,
 161             max(0, min(height, net.REAL_CHAIN_LENGTH) - 1),
 162             65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target),
 163         )
 164         assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
 165
 166         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
 167         this_script = bitcoin_data.pubkey_hash_to_script2(share_data['pubkey_hash'])
 168         amounts[this_script] = amounts.get(this_script, 0) + share_data['subsidy']//200 # 0.5% goes to block finder
 169         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
 170
 171         if sum(amounts.itervalues()) != share_data['subsidy'] or any(x < 0 for x in amounts.itervalues()):
 172             raise ValueError()
 173
 174         dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit
 175
 176         share_info = dict(
 177             share_data=share_data,
 178             far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
 179             max_bits=max_bits,
 180             bits=bits,
 181             timestamp=math.clip(desired_timestamp, (
 182                 (previous_share.timestamp + net.SHARE_PERIOD) - (net.SHARE_PERIOD - 1), # = previous_share.timestamp + 1
 183                 (previous_share.timestamp + net.SHARE_PERIOD) + (net.SHARE_PERIOD - 1),
 184             )) if previous_share is not None else desired_timestamp,
 185             new_transaction_hashes=new_transaction_hashes,
 186             transaction_hash_refs=transaction_hash_refs,
 187             absheight=((previous_share.absheight if previous_share is not None else 0) + 1) % 2**32,
 188             abswork=((previous_share.abswork if previous_share is not None else 0) + bitcoin_data.target_to_average_attempts(bits.target)) % 2**128,
 189         )
 190
 191         gentx = dict(
 192             version=1,
 193             # coinbase timestamp must be older than share/block timestamp
 194             # maybe there are more elegant solution, but this hack works quite well for now
 195             timestamp=share_info['timestamp'],
 196             tx_ins=[dict(
 197                 previous_output=None,
 198                 sequence=None,
 199                 script=share_data['coinbase'],
 200             )],
 201             tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT] + [dict(
 202                 value=0,
 203                 script='\x6a\x28' + cls.get_ref_hash(net, share_info, ref_merkle_link) + pack.IntType(64).pack(last_txout_nonce),
 204             )],
 205             lock_time=0,
 206         )
 207
 208         def get_share(header, last_txout_nonce=last_txout_nonce):
 209             min_header = dict(header); del min_header['merkle_root']
 210             share = cls(net, None, dict(
 211                 min_header=min_header,
 212                 share_info=share_info,
 213                 ref_merkle_link=dict(branch=[], index=0),
 214                 last_txout_nonce=last_txout_nonce,
 215                 hash_link=prefix_to_hash_link(bitcoin_data.tx_type.pack(gentx)[:-32-8-4], cls.gentx_before_refhash),
 216                 merkle_link=bitcoin_data.calculate_merkle_link([None] + other_transaction_hashes, 0),
 217             ))
 218             assert share.header == header # checks merkle_root
 219             return share
 220
 221         return share_info, gentx, other_transaction_hashes, get_share
 222
 223     @classmethod
 224     def get_ref_hash(cls, net, share_info, ref_merkle_link):
 225         return pack.IntType(256).pack(bitcoin_data.check_merkle_link(bitcoin_data.hash256(cls.ref_type.pack(dict(
 226             identifier=net.IDENTIFIER,
 227             share_info=share_info,
 228         ))), ref_merkle_link))
 229
 230     __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 absheight abswork'.split(' ')
 231
 232     def __init__(self, net, peer_addr, contents):
 233         self.net = net
 234         self.peer_addr = peer_addr
 235         self.contents = contents
 236
 237         self.min_header = contents['min_header']
 238         self.share_info = contents['share_info']
 239         self.hash_link = contents['hash_link']
 240         self.merkle_link = contents['merkle_link']
 241
 242         if not (2 <= len(self.share_info['share_data']['coinbase']) <= 100):
 243             raise ValueError('''bad coinbase size! %i bytes''' % (len(self.share_info['share_data']['coinbase']),))
 244
 245         if len(self.merkle_link['branch']) > 16:
 246             raise ValueError('merkle branch too long!')
 247
 248         assert not self.hash_link['extra_data'], repr(self.hash_link['extra_data'])
 249
 250         self.share_data = self.share_info['share_data']
 251         self.max_target = self.share_info['max_bits'].target
 252         self.target = self.share_info['bits'].target
 253         self.timestamp = self.share_info['timestamp']
 254         self.previous_hash = self.share_data['previous_share_hash']
 255         self.new_script = bitcoin_data.pubkey_hash_to_script2(self.share_data['pubkey_hash'])
 256         self.desired_version = self.share_data['desired_version']
 257         self.absheight = self.share_info['absheight']
 258         self.abswork = self.share_info['abswork']
 259
 260         n = set()
 261         for share_count, tx_count in self.iter_transaction_hash_refs():
 262             assert share_count < 110
 263             if share_count == 0:
 264                 n.add(tx_count)
 265         assert n == set(range(len(self.share_info['new_transaction_hashes'])))
 266
 267         self.gentx_hash = check_hash_link(
 268             self.hash_link,
 269             self.get_ref_hash(net, self.share_info, contents['ref_merkle_link']) + pack.IntType(64).pack(self.contents['last_txout_nonce']) + pack.IntType(32).pack(0),
 270             self.gentx_before_refhash,
 271         )
 272         merkle_root = bitcoin_data.check_merkle_link(self.gentx_hash, self.merkle_link)
 273         self.header = dict(self.min_header, merkle_root=merkle_root)
 274         self.pow_hash = self.hash = self.header_hash = bitcoin_data.scrypt(bitcoin_data.block_header_type.pack(self.header))
 275
 276         if self.target > net.MAX_TARGET:
 277             from p2pool import p2p
 278             raise p2p.PeerMisbehavingError('share target invalid')
 279
 280         if self.pow_hash > self.target:
 281             from p2pool import p2p
 282             raise p2p.PeerMisbehavingError('share PoW invalid')
 283
 284         self.new_transaction_hashes = self.share_info['new_transaction_hashes']
 285
 286         # XXX eww
 287         self.time_seen = time.time()
 288
 289     def __repr__(self):
 290         return 'Share' + repr((self.net, self.peer_addr, self.contents))
 291
 292     def as_share(self):
 293         return dict(type=self.VERSION, contents=self.share_type.pack(self.contents))
 294
 295     def iter_transaction_hash_refs(self):
 296         return zip(self.share_info['transaction_hash_refs'][::2], self.share_info['transaction_hash_refs'][1::2])
 297
 298     def check(self, tracker):
 299         from p2pool import p2p
 300         if self.share_data['previous_share_hash'] is not None:
 301             previous_share = tracker.items[self.share_data['previous_share_hash']]
 302             if type(self) is type(previous_share):
 303                 pass
 304             elif type(self) is type(previous_share).SUCCESSOR:
 305                 if tracker.get_height(previous_share.hash) < self.net.CHAIN_LENGTH:
 306                     from p2pool import p2p
 307                     raise p2p.PeerMisbehavingError('switch without enough history')
 308
 309                 # switch only valid if 85% of hashes in [self.net.CHAIN_LENGTH*9//10, self.net.CHAIN_LENGTH] for new version
 310                 counts = get_desired_version_counts(tracker,
 311                     tracker.get_nth_parent_hash(previous_share.hash, self.net.CHAIN_LENGTH*9//10), self.net.CHAIN_LENGTH//10)
 312                 if counts.get(self.VERSION, 0) < sum(counts.itervalues())*85//100:
 313                     raise p2p.PeerMisbehavingError('switch without enough hash power upgraded')
 314             else:
 315                 raise p2p.PeerMisbehavingError('''%s can't follow %s''' % (type(self).__name__, type(previous_share).__name__))
 316
 317         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()]
 318
 319         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'])
 320         assert other_tx_hashes2 == other_tx_hashes
 321 # workaround
 322 #        if share_info != self.share_info:
 323 #            raise ValueError('share_info invalid')
 324         if bitcoin_data.hash256(bitcoin_data.tx_type.pack(gentx)) != self.gentx_hash:
 325             raise ValueError('''gentx doesn't match hash_link''')
 326
 327         if bitcoin_data.calculate_merkle_link([None] + other_tx_hashes, 0) != self.merkle_link:
 328             raise ValueError('merkle_link and other_tx_hashes do not match')
 329
 330         return gentx # only used by as_block
 331
 332     def get_other_tx_hashes(self, tracker):
 333         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
 334         parents = tracker.get_height(self.hash) - 1
 335         if parents < parents_needed:
 336             return None
 337         last_shares = list(tracker.get_chain(self.hash, parents_needed + 1))
 338         return [last_shares[share_count].share_info['new_transaction_hashes'][tx_count] for share_count, tx_count in self.iter_transaction_hash_refs()]
 339
 340     def _get_other_txs(self, tracker, known_txs):
 341         other_tx_hashes = self.get_other_tx_hashes(tracker)
 342         if other_tx_hashes is None:
 343             return None # not all parents present
 344
 345         if not all(tx_hash in known_txs for tx_hash in other_tx_hashes):
 346             return None # not all txs present
 347
 348         return [known_txs[tx_hash] for tx_hash in other_tx_hashes]
 349
 350     def should_punish_reason(self, previous_block, bits, tracker, known_txs):
 351         if (self.header['previous_block'], self.header['bits']) != (previous_block, bits) and self.header_hash != previous_block and self.peer_addr is not None:
 352             return True, 'Block-stale detected! height(%x) < height(%x) or %08x != %08x' % (self.header['previous_block'], previous_block, self.header['bits'].bits, bits.bits)
 353
 354         if self.pow_hash <= self.header['bits'].target:
 355             return -1, 'block solution'
 356
 357         other_txs = self._get_other_txs(tracker, known_txs)
 358         if other_txs is None:
 359             pass
 360         else:
 361             all_txs_size = sum(bitcoin_data.tx_type.packed_size(tx) for tx in other_txs)
 362             if all_txs_size > 1000000:
 363                 return True, 'txs over block size limit'
 364
 365             new_txs_size = sum(bitcoin_data.tx_type.packed_size(known_txs[tx_hash]) for tx_hash in self.share_info['new_transaction_hashes'])
 366             if new_txs_size > 50000:
 367                 return True, 'new txs over limit'
 368
 369         return False, None
 370
 371     def as_block(self, tracker, known_txs):
 372         other_txs = self._get_other_txs(tracker, known_txs)
 373         if other_txs is None:
 374             return None # not all txs present
 375         return dict(header=self.header, txs=[self.check(tracker)] + other_txs, signature='')
 376
 377
 378 class WeightsSkipList(forest.TrackerSkipList):
 379     # share_count, weights, total_weight
 380
 381     def get_delta(self, element):
 382         from p2pool.bitcoin import data as bitcoin_data
 383         share = self.tracker.items[element]
 384         att = bitcoin_data.target_to_average_attempts(share.target)
 385         return 1, {share.new_script: att*(65535-share.share_data['donation'])}, att*65535, att*share.share_data['donation']
 386
 387     def combine_deltas(self, (share_count1, weights1, total_weight1, total_donation_weight1), (share_count2, weights2, total_weight2, total_donation_weight2)):
 388         return share_count1 + share_count2, math.add_dicts(weights1, weights2), total_weight1 + total_weight2, total_donation_weight1 + total_donation_weight2
 389
 390     def initial_solution(self, start, (max_shares, desired_weight)):
 391         assert desired_weight % 65535 == 0, divmod(desired_weight, 65535)
 392         return 0, None, 0, 0
 393
 394     def apply_delta(self, (share_count1, weights_list, total_weight1, total_donation_weight1), (share_count2, weights2, total_weight2, total_donation_weight2), (max_shares, desired_weight)):
 395         if total_weight1 + total_weight2 > desired_weight and share_count2 == 1:
 396             assert (desired_weight - total_weight1) % 65535 == 0
 397             script, = weights2.iterkeys()
 398             new_weights = {script: (desired_weight - total_weight1)//65535*weights2[script]//(total_weight2//65535)}
 399             return share_count1 + share_count2, (weights_list, new_weights), desired_weight, total_donation_weight1 + (desired_weight - total_weight1)//65535*total_donation_weight2//(total_weight2//65535)
 400         return share_count1 + share_count2, (weights_list, weights2), total_weight1 + total_weight2, total_donation_weight1 + total_donation_weight2
 401
 402     def judge(self, (share_count, weights_list, total_weight, total_donation_weight), (max_shares, desired_weight)):
 403         if share_count > max_shares or total_weight > desired_weight:
 404             return 1
 405         elif share_count == max_shares or total_weight == desired_weight:
 406             return 0
 407         else:
 408             return -1
 409
 410     def finalize(self, (share_count, weights_list, total_weight, total_donation_weight), (max_shares, desired_weight)):
 411         assert share_count <= max_shares and total_weight <= desired_weight
 412         assert share_count == max_shares or total_weight == desired_weight
 413         return math.add_dicts(*math.flatten_linked_list(weights_list)), total_weight, total_donation_weight
 414
 415 class OkayTracker(forest.Tracker):
 416     def __init__(self, net):
 417         forest.Tracker.__init__(self, delta_type=forest.get_attributedelta_type(dict(forest.AttributeDelta.attrs,
 418             work=lambda share: bitcoin_data.target_to_average_attempts(share.target),
 419             min_work=lambda share: bitcoin_data.target_to_average_attempts(share.max_target),
 420         )))
 421         self.net = net
 422         self.verified = forest.SubsetTracker(delta_type=forest.get_attributedelta_type(dict(forest.AttributeDelta.attrs,
 423             work=lambda share: bitcoin_data.target_to_average_attempts(share.target),
 424         )), subset_of=self)
 425         self.get_cumulative_weights = WeightsSkipList(self)
 426
 427     def attempt_verify(self, share):
 428         if share.hash in self.verified.items:
 429             return True
 430         height, last = self.get_height_and_last(share.hash)
 431         if height < self.net.CHAIN_LENGTH + 1 and last is not None:
 432             raise AssertionError()
 433         try:
 434             share.check(self)
 435         except:
 436             log.err(None, 'Share check failed: %064x -> %064x' % (share.hash, share.previous_hash if share.previous_hash is not None else 0))
 437             return False
 438         else:
 439             self.verified.add(share)
 440             return True
 441
 442     def think(self, block_rel_height_func, previous_block, bits, known_txs):
 443         desired = set()
 444         bad_peer_addresses = set()
 445
 446         # O(len(self.heads))
 447         #   make 'unverified heads' set?
 448         # for each overall head, attempt verification
 449         # if it fails, attempt on parent, and repeat
 450         # if no successful verification because of lack of parents, request parent
 451         bads = []
 452         for head in set(self.heads) - set(self.verified.heads):
 453             head_height, last = self.get_height_and_last(head)
 454
 455             for share in self.get_chain(head, head_height if last is None else min(5, max(0, head_height - self.net.CHAIN_LENGTH))):
 456                 if self.attempt_verify(share):
 457                     break
 458                 bads.append(share.hash)
 459             else:
 460                 if last is not None:
 461                     desired.add((
 462                         self.items[random.choice(list(self.reverse[last]))].peer_addr,
 463                         last,
 464                         max(x.timestamp for x in self.get_chain(head, min(head_height, 5))),
 465                         min(x.target for x in self.get_chain(head, min(head_height, 5))),
 466                     ))
 467         for bad in bads:
 468             assert bad not in self.verified.items
 469             #assert bad in self.heads
 470             bad_share = self.items[bad]
 471             if bad_share.peer_addr is not None:
 472                 bad_peer_addresses.add(bad_share.peer_addr)
 473             if p2pool.DEBUG:
 474                 print "BAD", bad
 475             try:
 476                 self.remove(bad)
 477             except NotImplementedError:
 478                 pass
 479
 480         # try to get at least CHAIN_LENGTH height for each verified head, requesting parents if needed
 481         for head in list(self.verified.heads):
 482             head_height, last_hash = self.verified.get_height_and_last(head)
 483             last_height, last_last_hash = self.get_height_and_last(last_hash)
 484             # XXX review boundary conditions
 485             want = max(self.net.CHAIN_LENGTH - head_height, 0)
 486             can = max(last_height - 1 - self.net.CHAIN_LENGTH, 0) if last_last_hash is not None else last_height
 487             get = min(want, can)
 488             #print 'Z', head_height, last_hash is None, last_height, last_last_hash is None, want, can, get
 489             for share in self.get_chain(last_hash, get):
 490                 if not self.attempt_verify(share):
 491                     break
 492             if head_height < self.net.CHAIN_LENGTH and last_last_hash is not None:
 493                 desired.add((
 494                     self.items[random.choice(list(self.verified.reverse[last_hash]))].peer_addr,
 495                     last_last_hash,
 496                     max(x.timestamp for x in self.get_chain(head, min(head_height, 5))),
 497                     min(x.target for x in self.get_chain(head, min(head_height, 5))),
 498                 ))
 499
 500         # decide best tree
 501         decorated_tails = sorted((self.score(max(self.verified.tails[tail_hash], key=self.verified.get_work), block_rel_height_func), tail_hash) for tail_hash in self.verified.tails)
 502         if p2pool.DEBUG:
 503             print len(decorated_tails), 'tails:'
 504             for score, tail_hash in decorated_tails:
 505                 print format_hash(tail_hash), score
 506         best_tail_score, best_tail = decorated_tails[-1] if decorated_tails else (None, None)
 507
 508         # decide best verified head
 509         decorated_heads = sorted(((
 510             self.verified.get_work(self.verified.get_nth_parent_hash(h, min(5, self.verified.get_height(h)))),
 511             #self.items[h].peer_addr is None,
 512             -self.items[h].should_punish_reason(previous_block, bits, self, known_txs)[0],
 513             -self.items[h].time_seen,
 514         ), h) for h in self.verified.tails.get(best_tail, []))
 515         if p2pool.DEBUG:
 516             print len(decorated_heads), 'heads. Top 10:'
 517             for score, head_hash in decorated_heads[-10:]:
 518                 print '   ', format_hash(head_hash), format_hash(self.items[head_hash].previous_hash), score
 519         best_head_score, best = decorated_heads[-1] if decorated_heads else (None, None)
 520
 521         if best is not None:
 522             best_share = self.items[best]
 523             punish, punish_reason = best_share.should_punish_reason(previous_block, bits, self, known_txs)
 524             if punish > 0:
 525                 print 'Punishing share for %r! Jumping from %s to %s!' % (punish_reason, format_hash(best), format_hash(best_share.previous_hash))
 526                 best = best_share.previous_hash
 527
 528             timestamp_cutoff = min(int(time.time()), best_share.timestamp) - 3600
 529             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
 530         else:
 531             timestamp_cutoff = int(time.time()) - 24*60*60
 532             target_cutoff = 2**256-1
 533
 534         if p2pool.DEBUG:
 535             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))
 536             for peer_addr, hash, ts, targ in desired:
 537                 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
 538
 539         return best, [(peer_addr, hash) for peer_addr, hash, ts, targ in desired if ts >= timestamp_cutoff], decorated_heads, bad_peer_addresses
 540
 541     def score(self, share_hash, block_rel_height_func):
 542         # returns approximate lower bound on chain's hashrate in the last self.net.CHAIN_LENGTH*15//16*self.net.SHARE_PERIOD time
 543
 544         head_height = self.verified.get_height(share_hash)
 545         if head_height < self.net.CHAIN_LENGTH:
 546             return head_height, None
 547
 548         end_point = self.verified.get_nth_parent_hash(share_hash, self.net.CHAIN_LENGTH*15//16)
 549
 550         block_height = max(block_rel_height_func(share.header['previous_block']) for share in
 551             self.verified.get_chain(end_point, self.net.CHAIN_LENGTH//16))
 552
 553         return self.net.CHAIN_LENGTH, self.verified.get_delta(share_hash, end_point).work/((0 - block_height + 1)*self.net.PARENT.BLOCK_PERIOD)
 554
 555 def get_pool_attempts_per_second(tracker, previous_share_hash, dist, min_work=False, integer=False):
 556     assert dist >= 2
 557     near = tracker.items[previous_share_hash]
 558     far = tracker.items[tracker.get_nth_parent_hash(previous_share_hash, dist - 1)]
 559     attempts = tracker.get_delta(near.hash, far.hash).work if not min_work else tracker.get_delta(near.hash, far.hash).min_work
 560     time = near.timestamp - far.timestamp
 561     if time <= 0:
 562         time = 1
 563     if integer:
 564         return attempts//time
 565     return attempts/time
 566
 567 def get_average_stale_prop(tracker, share_hash, lookbehind):
 568     stales = sum(1 for share in tracker.get_chain(share_hash, lookbehind) if share.share_data['stale_info'] is not None)
 569     return stales/(lookbehind + stales)
 570
 571 def get_stale_counts(tracker, share_hash, lookbehind, rates=False):
 572     res = {}
 573     for share in tracker.get_chain(share_hash, lookbehind - 1):
 574         res['good'] = res.get('good', 0) + bitcoin_data.target_to_average_attempts(share.target)
 575         s = share.share_data['stale_info']
 576         if s is not None:
 577             res[s] = res.get(s, 0) + bitcoin_data.target_to_average_attempts(share.target)
 578     if rates:
 579         dt = tracker.items[share_hash].timestamp - tracker.items[tracker.get_nth_parent_hash(share_hash, lookbehind - 1)].timestamp
 580         res = dict((k, v/dt) for k, v in res.iteritems())
 581     return res
 582
 583 def get_user_stale_props(tracker, share_hash, lookbehind):
 584     res = {}
 585     for share in tracker.get_chain(share_hash, lookbehind - 1):
 586         stale, total = res.get(share.share_data['pubkey_hash'], (0, 0))
 587         total += 1
 588         if share.share_data['stale_info'] is not None:
 589             stale += 1
 590             total += 1
 591         res[share.share_data['pubkey_hash']] = stale, total
 592     return dict((pubkey_hash, stale/total) for pubkey_hash, (stale, total) in res.iteritems())
 593
 594 def get_expected_payouts(tracker, best_share_hash, block_target, subsidy, net):
 595     weights, total_weight, donation_weight = tracker.get_cumulative_weights(best_share_hash, min(tracker.get_height(best_share_hash), net.REAL_CHAIN_LENGTH), 65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target))
 596     res = dict((script, subsidy*weight//total_weight) for script, weight in weights.iteritems())
 597     res[DONATION_SCRIPT] = res.get(DONATION_SCRIPT, 0) + subsidy - sum(res.itervalues())
 598     return res
 599
 600 def get_desired_version_counts(tracker, best_share_hash, dist):
 601     res = {}
 602     for share in tracker.get_chain(best_share_hash, dist):
 603         res[share.desired_version] = res.get(share.desired_version, 0) + bitcoin_data.target_to_average_attempts(share.target)
 604     return res
 605
 606 def get_warnings(tracker, best_share, net, bitcoind_getinfo, bitcoind_work_value):
 607     res = []
 608
 609     desired_version_counts = get_desired_version_counts(tracker, best_share,
 610         min(net.CHAIN_LENGTH, 60*60//net.SHARE_PERIOD, tracker.get_height(best_share)))
 611     majority_desired_version = max(desired_version_counts, key=lambda k: desired_version_counts[k])
 612     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:
 613         res.append('A MAJORITY OF SHARES CONTAIN A VOTE FOR AN UNSUPPORTED SHARE IMPLEMENTATION! (v%i with %i%% support)\n'
 614             'An upgrade is likely necessary. Check http://p2pool.forre.st/ for more information.' % (
 615                 majority_desired_version, 100*desired_version_counts[majority_desired_version]/sum(desired_version_counts.itervalues())))
 616
 617     if bitcoind_getinfo['errors'] != '':
 618         if 'This is a pre-release test build' not in bitcoind_getinfo['errors']:
 619             res.append('(from bitcoind) %s' % (bitcoind_getinfo['errors'],))
 620
 621     version_warning = getattr(net, 'VERSION_WARNING', lambda v: None)(bitcoind_getinfo['version'])
 622     if version_warning is not None:
 623         res.append(version_warning)
 624
 625     if time.time() > bitcoind_work_value['last_update'] + 60:
 626         res.append('''LOST CONTACT WITH BITCOIND for %s! Check that it isn't frozen or dead!''' % (math.format_dt(time.time() - bitcoind_work_value['last_update']),))
 627
 628     return res
 629
 630 def format_hash(x):
 631     if x is None:
 632         return 'xxxxxxxx'
 633     return '%08x' % (x % 2**32)
 634
 635 class ShareStore(object):
 636     def __init__(self, prefix, net, share_cb, verified_hash_cb):
 637         self.dirname = os.path.dirname(os.path.abspath(prefix))
 638         self.filename = os.path.basename(os.path.abspath(prefix))
 639         self.net = net
 640
 641         known = {}
 642         filenames, next = self.get_filenames_and_next()
 643         for filename in filenames:
 644             share_hashes, verified_hashes = known.setdefault(filename, (set(), set()))
 645             with open(filename, 'rb') as f:
 646                 for line in f:
 647                     try:
 648                         type_id_str, data_hex = line.strip().split(' ')
 649                         type_id = int(type_id_str)
 650                         if type_id == 0:
 651                             pass
 652                         elif type_id == 1:
 653                             pass
 654                         elif type_id == 2:
 655                             verified_hash = int(data_hex, 16)
 656                             verified_hash_cb(verified_hash)
 657                             verified_hashes.add(verified_hash)
 658                         elif type_id == 5:
 659                             raw_share = share_type.unpack(data_hex.decode('hex'))
 660                             if raw_share['type'] < Share.VERSION:
 661                                 continue
 662                             share = load_share(raw_share, self.net, None)
 663                             share_cb(share)
 664                             share_hashes.add(share.hash)
 665                         else:
 666                             raise NotImplementedError("share type %i" % (type_id,))
 667                     except Exception:
 668                         log.err(None, "HARMLESS error while reading saved shares, continuing where left off:")
 669
 670         self.known = known # filename -> (set of share hashes, set of verified hashes)
 671         self.known_desired = dict((k, (set(a), set(b))) for k, (a, b) in known.iteritems())
 672
 673     def _add_line(self, line):
 674         filenames, next = self.get_filenames_and_next()
 675         if filenames and os.path.getsize(filenames[-1]) < 10e6:
 676             filename = filenames[-1]
 677         else:
 678             filename = next
 679
 680         with open(filename, 'ab') as f:
 681             f.write(line + '\n')
 682
 683         return filename
 684
 685     def add_share(self, share):
 686         for filename, (share_hashes, verified_hashes) in self.known.iteritems():
 687             if share.hash in share_hashes:
 688                 break
 689         else:
 690             filename = self._add_line("%i %s" % (5, share_type.pack(share.as_share()).encode('hex')))
 691             share_hashes, verified_hashes = self.known.setdefault(filename, (set(), set()))
 692             share_hashes.add(share.hash)
 693         share_hashes, verified_hashes = self.known_desired.setdefault(filename, (set(), set()))
 694         share_hashes.add(share.hash)
 695
 696     def add_verified_hash(self, share_hash):
 697         for filename, (share_hashes, verified_hashes) in self.known.iteritems():
 698             if share_hash in verified_hashes:
 699                 break
 700         else:
 701             filename = self._add_line("%i %x" % (2, share_hash))
 702             share_hashes, verified_hashes = self.known.setdefault(filename, (set(), set()))
 703             verified_hashes.add(share_hash)
 704         share_hashes, verified_hashes = self.known_desired.setdefault(filename, (set(), set()))
 705         verified_hashes.add(share_hash)
 706
 707     def get_filenames_and_next(self):
 708         suffixes = sorted(int(x[len(self.filename):]) for x in os.listdir(self.dirname) if x.startswith(self.filename) and x[len(self.filename):].isdigit())
 709         return [os.path.join(self.dirname, self.filename + str(suffix)) for suffix in suffixes], os.path.join(self.dirname, self.filename + (str(suffixes[-1] + 1) if suffixes else str(0)))
 710
 711     def forget_share(self, share_hash):
 712         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
 713             if share_hash in share_hashes:
 714                 share_hashes.remove(share_hash)
 715         self.check_remove()
 716
 717     def forget_verified_share(self, share_hash):
 718         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
 719             if share_hash in verified_hashes:
 720                 verified_hashes.remove(share_hash)
 721         self.check_remove()
 722
 723     def check_remove(self):
 724         to_remove = set()
 725         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
 726             #print filename, len(share_hashes) + len(verified_hashes)
 727             if not share_hashes and not verified_hashes:
 728                 to_remove.add(filename)
 729         for filename in to_remove:
 730             self.known.pop(filename)
 731             self.known_desired.pop(filename)
 732             os.remove(filename)
 733             print "REMOVED", filename