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  = '41043b253cc0b5c8ce26f24b84bb955bec955cbb4643f19ab7ea073884f22874abdafc42040b97efec3c9eeb29ce69022a96cc1772f8bc805f78af0d3dc5c441db5fac'.decode('hex')
  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                     if known_txs[tx_hash]['timestamp'] > desired_timestamp - 30:
 143                         continue
 144                     this_size = bitcoin_data.tx_type.packed_size(known_txs[tx_hash])
 145                     if new_transaction_size + this_size > 50000: # only allow 50 kB of new txns/share
 146                         break
 147                     new_transaction_size += this_size
 148                 new_transaction_hashes.append(tx_hash)
 149                 this = [0, len(new_transaction_hashes)-1]
 150             transaction_hash_refs.extend(this)
 151             other_transaction_hashes.append(tx_hash)
 152
 153         included_transactions = set(other_transaction_hashes)
 154         removed_fees = [fee for tx_hash, fee in desired_other_transaction_hashes_and_fees if tx_hash not in included_transactions]
 155         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)
 156         if None not in removed_fees:
 157             share_data = dict(share_data, subsidy=share_data['subsidy'])
 158         else:
 159             assert base_subsidy is not None
 160             share_data = dict(share_data, subsidy=base_subsidy)
 161
 162         weights, total_weight, donation_weight = tracker.get_cumulative_weights(previous_share.share_data['previous_share_hash'] if previous_share is not None else None,
 163             max(0, min(height, net.REAL_CHAIN_LENGTH) - 1),
 164             65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target),
 165         )
 166         assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
 167
 168         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
 169         this_script = bitcoin_data.pubkey_hash_to_script2(share_data['pubkey_hash'])
 170         amounts[this_script] = amounts.get(this_script, 0) + share_data['subsidy']//200 # 0.5% goes to block finder
 171         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
 172
 173         if sum(amounts.itervalues()) != share_data['subsidy'] or any(x < 0 for x in amounts.itervalues()):
 174             raise ValueError()
 175
 176         dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit
 177
 178         share_info = dict(
 179             share_data=share_data,
 180             far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
 181             max_bits=max_bits,
 182             bits=bits,
 183             timestamp=math.clip(desired_timestamp, (
 184                 (previous_share.timestamp + net.SHARE_PERIOD) - (net.SHARE_PERIOD - 1), # = previous_share.timestamp + 1
 185                 (previous_share.timestamp + net.SHARE_PERIOD) + (net.SHARE_PERIOD - 1),
 186             )) if previous_share is not None else desired_timestamp,
 187             new_transaction_hashes=new_transaction_hashes,
 188             transaction_hash_refs=transaction_hash_refs,
 189             absheight=((previous_share.absheight if previous_share is not None else 0) + 1) % 2**32,
 190             abswork=((previous_share.abswork if previous_share is not None else 0) + bitcoin_data.target_to_average_attempts(bits.target)) % 2**128,
 191         )
 192
 193         gentx = dict(
 194             version=1,
 195             # coinbase timestamp must be older than share/block timestamp
 196             # maybe there are more elegant solution, but this hack works quite well for now
 197             timestamp=share_info['timestamp'],
 198             tx_ins=[dict(
 199                 previous_output=None,
 200                 sequence=None,
 201                 script=share_data['coinbase'],
 202             )],
 203             tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT] + [dict(
 204                 value=0,
 205                 script='\x6a\x28' + cls.get_ref_hash(net, share_info, ref_merkle_link) + pack.IntType(64).pack(last_txout_nonce),
 206             )],
 207             lock_time=0,
 208         )
 209
 210         def get_share(header, last_txout_nonce=last_txout_nonce):
 211             min_header = dict(header); del min_header['merkle_root']
 212             share = cls(net, None, dict(
 213                 min_header=min_header,
 214                 share_info=share_info,
 215                 ref_merkle_link=dict(branch=[], index=0),
 216                 last_txout_nonce=last_txout_nonce,
 217                 hash_link=prefix_to_hash_link(bitcoin_data.tx_type.pack(gentx)[:-32-8-4], cls.gentx_before_refhash),
 218                 merkle_link=bitcoin_data.calculate_merkle_link([None] + other_transaction_hashes, 0),
 219             ))
 220             assert share.header == header # checks merkle_root
 221             return share
 222
 223         return share_info, gentx, other_transaction_hashes, get_share
 224
 225     @classmethod
 226     def get_ref_hash(cls, net, share_info, ref_merkle_link):
 227         return pack.IntType(256).pack(bitcoin_data.check_merkle_link(bitcoin_data.hash256(cls.ref_type.pack(dict(
 228             identifier=net.IDENTIFIER,
 229             share_info=share_info,
 230         ))), ref_merkle_link))
 231
 232     __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(' ')
 233
 234     def __init__(self, net, peer_addr, contents):
 235         self.net = net
 236         self.peer_addr = peer_addr
 237         self.contents = contents
 238
 239         self.min_header = contents['min_header']
 240         self.share_info = contents['share_info']
 241         self.hash_link = contents['hash_link']
 242         self.merkle_link = contents['merkle_link']
 243
 244         if not (2 <= len(self.share_info['share_data']['coinbase']) <= 100):
 245             raise ValueError('''bad coinbase size! %i bytes''' % (len(self.share_info['share_data']['coinbase']),))
 246
 247         if len(self.merkle_link['branch']) > 16:
 248             raise ValueError('merkle branch too long!')
 249
 250         assert not self.hash_link['extra_data'], repr(self.hash_link['extra_data'])
 251
 252         self.share_data = self.share_info['share_data']
 253         self.max_target = self.share_info['max_bits'].target
 254         self.target = self.share_info['bits'].target
 255         self.timestamp = self.share_info['timestamp']
 256         self.previous_hash = self.share_data['previous_share_hash']
 257         self.new_script = bitcoin_data.pubkey_hash_to_script2(self.share_data['pubkey_hash'])
 258         self.desired_version = self.share_data['desired_version']
 259         self.absheight = self.share_info['absheight']
 260         self.abswork = self.share_info['abswork']
 261
 262         n = set()
 263         for share_count, tx_count in self.iter_transaction_hash_refs():
 264             assert share_count < 110
 265             if share_count == 0:
 266                 n.add(tx_count)
 267         assert n == set(range(len(self.share_info['new_transaction_hashes'])))
 268
 269         self.gentx_hash = check_hash_link(
 270             self.hash_link,
 271             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),
 272             self.gentx_before_refhash,
 273         )
 274         merkle_root = bitcoin_data.check_merkle_link(self.gentx_hash, self.merkle_link)
 275         self.header = dict(self.min_header, merkle_root=merkle_root)
 276         self.pow_hash = self.hash = self.header_hash = bitcoin_data.scrypt(bitcoin_data.block_header_type.pack(self.header))
 277
 278         if self.target > net.MAX_TARGET:
 279             from p2pool import p2p
 280             raise p2p.PeerMisbehavingError('share target invalid')
 281
 282         if self.pow_hash > self.target:
 283             from p2pool import p2p
 284             raise p2p.PeerMisbehavingError('share PoW invalid')
 285
 286         self.new_transaction_hashes = self.share_info['new_transaction_hashes']
 287
 288         # XXX eww
 289         self.time_seen = time.time()
 290
 291     def __repr__(self):
 292         return 'Share' + repr((self.net, self.peer_addr, self.contents))
 293
 294     def as_share(self):
 295         return dict(type=self.VERSION, contents=self.share_type.pack(self.contents))
 296
 297     def iter_transaction_hash_refs(self):
 298         return zip(self.share_info['transaction_hash_refs'][::2], self.share_info['transaction_hash_refs'][1::2])
 299
 300     def check(self, tracker):
 301         from p2pool import p2p
 302         if self.share_data['previous_share_hash'] is not None:
 303             previous_share = tracker.items[self.share_data['previous_share_hash']]
 304             if type(self) is type(previous_share):
 305                 pass
 306             elif type(self) is type(previous_share).SUCCESSOR:
 307                 if tracker.get_height(previous_share.hash) < self.net.CHAIN_LENGTH:
 308                     from p2pool import p2p
 309                     raise p2p.PeerMisbehavingError('switch without enough history')
 310
 311                 # switch only valid if 85% of hashes in [self.net.CHAIN_LENGTH*9//10, self.net.CHAIN_LENGTH] for new version
 312                 counts = get_desired_version_counts(tracker,
 313                     tracker.get_nth_parent_hash(previous_share.hash, self.net.CHAIN_LENGTH*9//10), self.net.CHAIN_LENGTH//10)
 314                 if counts.get(self.VERSION, 0) < sum(counts.itervalues())*85//100:
 315                     raise p2p.PeerMisbehavingError('switch without enough hash power upgraded')
 316             else:
 317                 raise p2p.PeerMisbehavingError('''%s can't follow %s''' % (type(self).__name__, type(previous_share).__name__))
 318
 319         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()]
 320
 321         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'])
 322         assert other_tx_hashes2 == other_tx_hashes
 323 # workaround
 324         if share_info != self.share_info:
 325             raise ValueError('share_info invalid')
 326         if bitcoin_data.hash256(bitcoin_data.tx_type.pack(gentx)) != self.gentx_hash:
 327             raise ValueError('''gentx doesn't match hash_link''')
 328
 329         if bitcoin_data.calculate_merkle_link([None] + other_tx_hashes, 0) != self.merkle_link:
 330             raise ValueError('merkle_link and other_tx_hashes do not match')
 331
 332         return gentx # only used by as_block
 333
 334     def get_other_tx_hashes(self, tracker):
 335         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
 336         parents = tracker.get_height(self.hash) - 1
 337         if parents < parents_needed:
 338             return None
 339         last_shares = list(tracker.get_chain(self.hash, parents_needed + 1))
 340         return [last_shares[share_count].share_info['new_transaction_hashes'][tx_count] for share_count, tx_count in self.iter_transaction_hash_refs()]
 341
 342     def _get_other_txs(self, tracker, known_txs):
 343         other_tx_hashes = self.get_other_tx_hashes(tracker)
 344         if other_tx_hashes is None:
 345             return None # not all parents present
 346
 347         if not all(tx_hash in known_txs for tx_hash in other_tx_hashes):
 348             return None # not all txs present
 349
 350         return [known_txs[tx_hash] for tx_hash in other_tx_hashes]
 351
 352     def should_punish_reason(self, previous_block, bits, tracker, known_txs):
 353         if (self.header['previous_block'], self.header['bits']) != (previous_block, bits) and self.header_hash != previous_block and self.peer_addr is not None:
 354             return True, 'Block-stale detected! height(%x) < height(%x) or %08x != %08x' % (self.header['previous_block'], previous_block, self.header['bits'].bits, bits.bits)
 355
 356         if self.pow_hash <= self.header['bits'].target:
 357             return -1, 'block solution'
 358
 359         other_txs = self._get_other_txs(tracker, known_txs)
 360         if other_txs is None:
 361             pass
 362         else:
 363             all_txs_size = sum(bitcoin_data.tx_type.packed_size(tx) for tx in other_txs)
 364             if all_txs_size > 1000000:
 365                 return True, 'txs over block size limit'
 366
 367             new_txs_size = sum(bitcoin_data.tx_type.packed_size(known_txs[tx_hash]) for tx_hash in self.share_info['new_transaction_hashes'])
 368             if new_txs_size > 50000:
 369                 return True, 'new txs over limit'
 370
 371         return False, None
 372
 373     def as_block(self, tracker, known_txs):
 374         other_txs = self._get_other_txs(tracker, known_txs)
 375         if other_txs is None:
 376             return None # not all txs present
 377         return dict(header=self.header, txs=[self.check(tracker)] + other_txs, signature='')
 378
 379
 380 class WeightsSkipList(forest.TrackerSkipList):
 381     # share_count, weights, total_weight
 382
 383     def get_delta(self, element):
 384         from p2pool.bitcoin import data as bitcoin_data
 385         share = self.tracker.items[element]
 386         att = bitcoin_data.target_to_average_attempts(share.target)
 387         return 1, {share.new_script: att*(65535-share.share_data['donation'])}, att*65535, att*share.share_data['donation']
 388
 389     def combine_deltas(self, (share_count1, weights1, total_weight1, total_donation_weight1), (share_count2, weights2, total_weight2, total_donation_weight2)):
 390         return share_count1 + share_count2, math.add_dicts(weights1, weights2), total_weight1 + total_weight2, total_donation_weight1 + total_donation_weight2
 391
 392     def initial_solution(self, start, (max_shares, desired_weight)):
 393         assert desired_weight % 65535 == 0, divmod(desired_weight, 65535)
 394         return 0, None, 0, 0
 395
 396     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)):
 397         if total_weight1 + total_weight2 > desired_weight and share_count2 == 1:
 398             assert (desired_weight - total_weight1) % 65535 == 0
 399             script, = weights2.iterkeys()
 400             new_weights = {script: (desired_weight - total_weight1)//65535*weights2[script]//(total_weight2//65535)}
 401             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)
 402         return share_count1 + share_count2, (weights_list, weights2), total_weight1 + total_weight2, total_donation_weight1 + total_donation_weight2
 403
 404     def judge(self, (share_count, weights_list, total_weight, total_donation_weight), (max_shares, desired_weight)):
 405         if share_count > max_shares or total_weight > desired_weight:
 406             return 1
 407         elif share_count == max_shares or total_weight == desired_weight:
 408             return 0
 409         else:
 410             return -1
 411
 412     def finalize(self, (share_count, weights_list, total_weight, total_donation_weight), (max_shares, desired_weight)):
 413         assert share_count <= max_shares and total_weight <= desired_weight
 414         assert share_count == max_shares or total_weight == desired_weight
 415         return math.add_dicts(*math.flatten_linked_list(weights_list)), total_weight, total_donation_weight
 416
 417 class OkayTracker(forest.Tracker):
 418     def __init__(self, net):
 419         forest.Tracker.__init__(self, delta_type=forest.get_attributedelta_type(dict(forest.AttributeDelta.attrs,
 420             work=lambda share: bitcoin_data.target_to_average_attempts(share.target),
 421             min_work=lambda share: bitcoin_data.target_to_average_attempts(share.max_target),
 422         )))
 423         self.net = net
 424         self.verified = forest.SubsetTracker(delta_type=forest.get_attributedelta_type(dict(forest.AttributeDelta.attrs,
 425             work=lambda share: bitcoin_data.target_to_average_attempts(share.target),
 426         )), subset_of=self)
 427         self.get_cumulative_weights = WeightsSkipList(self)
 428
 429     def attempt_verify(self, share):
 430         if share.hash in self.verified.items:
 431             return True
 432         height, last = self.get_height_and_last(share.hash)
 433         if height < self.net.CHAIN_LENGTH + 1 and last is not None:
 434             raise AssertionError()
 435         try:
 436             share.check(self)
 437         except:
 438             log.err(None, 'Share check failed: %064x -> %064x' % (share.hash, share.previous_hash if share.previous_hash is not None else 0))
 439             return False
 440         else:
 441             self.verified.add(share)
 442             return True
 443
 444     def think(self, block_rel_height_func, previous_block, bits, known_txs):
 445         desired = set()
 446         bad_peer_addresses = set()
 447
 448         # O(len(self.heads))
 449         #   make 'unverified heads' set?
 450         # for each overall head, attempt verification
 451         # if it fails, attempt on parent, and repeat
 452         # if no successful verification because of lack of parents, request parent
 453         bads = []
 454         for head in set(self.heads) - set(self.verified.heads):
 455             head_height, last = self.get_height_and_last(head)
 456
 457             for share in self.get_chain(head, head_height if last is None else min(5, max(0, head_height - self.net.CHAIN_LENGTH))):
 458                 if self.attempt_verify(share):
 459                     break
 460                 bads.append(share.hash)
 461             else:
 462                 if last is not None:
 463                     desired.add((
 464                         self.items[random.choice(list(self.reverse[last]))].peer_addr,
 465                         last,
 466                         max(x.timestamp for x in self.get_chain(head, min(head_height, 5))),
 467                         min(x.target for x in self.get_chain(head, min(head_height, 5))),
 468                     ))
 469         for bad in bads:
 470             assert bad not in self.verified.items
 471             #assert bad in self.heads
 472             bad_share = self.items[bad]
 473             if bad_share.peer_addr is not None:
 474                 bad_peer_addresses.add(bad_share.peer_addr)
 475             if p2pool.DEBUG:
 476                 print "BAD", bad
 477             try:
 478                 self.remove(bad)
 479             except NotImplementedError:
 480                 pass
 481
 482         # try to get at least CHAIN_LENGTH height for each verified head, requesting parents if needed
 483         for head in list(self.verified.heads):
 484             head_height, last_hash = self.verified.get_height_and_last(head)
 485             last_height, last_last_hash = self.get_height_and_last(last_hash)
 486             # XXX review boundary conditions
 487             want = max(self.net.CHAIN_LENGTH - head_height, 0)
 488             can = max(last_height - 1 - self.net.CHAIN_LENGTH, 0) if last_last_hash is not None else last_height
 489             get = min(want, can)
 490             #print 'Z', head_height, last_hash is None, last_height, last_last_hash is None, want, can, get
 491             for share in self.get_chain(last_hash, get):
 492                 if not self.attempt_verify(share):
 493                     break
 494             if head_height < self.net.CHAIN_LENGTH and last_last_hash is not None:
 495                 desired.add((
 496                     self.items[random.choice(list(self.verified.reverse[last_hash]))].peer_addr,
 497                     last_last_hash,
 498                     max(x.timestamp for x in self.get_chain(head, min(head_height, 5))),
 499                     min(x.target for x in self.get_chain(head, min(head_height, 5))),
 500                 ))
 501
 502         # decide best tree
 503         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)
 504         if p2pool.DEBUG:
 505             print len(decorated_tails), 'tails:'
 506             for score, tail_hash in decorated_tails:
 507                 print format_hash(tail_hash), score
 508         best_tail_score, best_tail = decorated_tails[-1] if decorated_tails else (None, None)
 509
 510         # decide best verified head
 511         decorated_heads = sorted(((
 512             self.verified.get_work(self.verified.get_nth_parent_hash(h, min(5, self.verified.get_height(h)))),
 513             #self.items[h].peer_addr is None,
 514             -self.items[h].should_punish_reason(previous_block, bits, self, known_txs)[0],
 515             -self.items[h].time_seen,
 516         ), h) for h in self.verified.tails.get(best_tail, []))
 517         if p2pool.DEBUG:
 518             print len(decorated_heads), 'heads. Top 10:'
 519             for score, head_hash in decorated_heads[-10:]:
 520                 print '   ', format_hash(head_hash), format_hash(self.items[head_hash].previous_hash), score
 521         best_head_score, best = decorated_heads[-1] if decorated_heads else (None, None)
 522
 523         if best is not None:
 524             best_share = self.items[best]
 525             punish, punish_reason = best_share.should_punish_reason(previous_block, bits, self, known_txs)
 526             if punish > 0:
 527                 print 'Punishing share for %r! Jumping from %s to %s!' % (punish_reason, format_hash(best), format_hash(best_share.previous_hash))
 528                 best = best_share.previous_hash
 529
 530             timestamp_cutoff = min(int(time.time()), best_share.timestamp) - 3600
 531             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
 532         else:
 533             timestamp_cutoff = int(time.time()) - 24*60*60
 534             target_cutoff = 2**256-1
 535
 536         if p2pool.DEBUG:
 537             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))
 538             for peer_addr, hash, ts, targ in desired:
 539                 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
 540
 541         return best, [(peer_addr, hash) for peer_addr, hash, ts, targ in desired if ts >= timestamp_cutoff], decorated_heads, bad_peer_addresses
 542
 543     def score(self, share_hash, block_rel_height_func):
 544         # returns approximate lower bound on chain's hashrate in the last self.net.CHAIN_LENGTH*15//16*self.net.SHARE_PERIOD time
 545
 546         head_height = self.verified.get_height(share_hash)
 547         if head_height < self.net.CHAIN_LENGTH:
 548             return head_height, None
 549
 550         end_point = self.verified.get_nth_parent_hash(share_hash, self.net.CHAIN_LENGTH*15//16)
 551
 552         block_height = max(block_rel_height_func(share.header['previous_block']) for share in
 553             self.verified.get_chain(end_point, self.net.CHAIN_LENGTH//16))
 554
 555         return self.net.CHAIN_LENGTH, self.verified.get_delta(share_hash, end_point).work/((0 - block_height + 1)*self.net.PARENT.BLOCK_PERIOD)
 556
 557 def get_pool_attempts_per_second(tracker, previous_share_hash, dist, min_work=False, integer=False):
 558     assert dist >= 2
 559     near = tracker.items[previous_share_hash]
 560     far = tracker.items[tracker.get_nth_parent_hash(previous_share_hash, dist - 1)]
 561     attempts = tracker.get_delta(near.hash, far.hash).work if not min_work else tracker.get_delta(near.hash, far.hash).min_work
 562     time = near.timestamp - far.timestamp
 563     if time <= 0:
 564         time = 1
 565     if integer:
 566         return attempts//time
 567     return attempts/time
 568
 569 def get_average_stale_prop(tracker, share_hash, lookbehind):
 570     stales = sum(1 for share in tracker.get_chain(share_hash, lookbehind) if share.share_data['stale_info'] is not None)
 571     return stales/(lookbehind + stales)
 572
 573 def get_stale_counts(tracker, share_hash, lookbehind, rates=False):
 574     res = {}
 575     for share in tracker.get_chain(share_hash, lookbehind - 1):
 576         res['good'] = res.get('good', 0) + bitcoin_data.target_to_average_attempts(share.target)
 577         s = share.share_data['stale_info']
 578         if s is not None:
 579             res[s] = res.get(s, 0) + bitcoin_data.target_to_average_attempts(share.target)
 580     if rates:
 581         dt = tracker.items[share_hash].timestamp - tracker.items[tracker.get_nth_parent_hash(share_hash, lookbehind - 1)].timestamp
 582         res = dict((k, v/dt) for k, v in res.iteritems())
 583     return res
 584
 585 def get_user_stale_props(tracker, share_hash, lookbehind):
 586     res = {}
 587     for share in tracker.get_chain(share_hash, lookbehind - 1):
 588         stale, total = res.get(share.share_data['pubkey_hash'], (0, 0))
 589         total += 1
 590         if share.share_data['stale_info'] is not None:
 591             stale += 1
 592             total += 1
 593         res[share.share_data['pubkey_hash']] = stale, total
 594     return dict((pubkey_hash, stale/total) for pubkey_hash, (stale, total) in res.iteritems())
 595
 596 def get_expected_payouts(tracker, best_share_hash, block_target, subsidy, net):
 597     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))
 598     res = dict((script, subsidy*weight//total_weight) for script, weight in weights.iteritems())
 599     res[DONATION_SCRIPT] = res.get(DONATION_SCRIPT, 0) + subsidy - sum(res.itervalues())
 600     return res
 601
 602 def get_desired_version_counts(tracker, best_share_hash, dist):
 603     res = {}
 604     for share in tracker.get_chain(best_share_hash, dist):
 605         res[share.desired_version] = res.get(share.desired_version, 0) + bitcoin_data.target_to_average_attempts(share.target)
 606     return res
 607
 608 def get_warnings(tracker, best_share, net, bitcoind_getinfo, bitcoind_work_value):
 609     res = []
 610
 611     desired_version_counts = get_desired_version_counts(tracker, best_share,
 612         min(net.CHAIN_LENGTH, 60*60//net.SHARE_PERIOD, tracker.get_height(best_share)))
 613     majority_desired_version = max(desired_version_counts, key=lambda k: desired_version_counts[k])
 614     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:
 615         res.append('A MAJORITY OF SHARES CONTAIN A VOTE FOR AN UNSUPPORTED SHARE IMPLEMENTATION! (v%i with %i%% support)\n'
 616             'An upgrade is likely necessary. Check http://p2pool.forre.st/ for more information.' % (
 617                 majority_desired_version, 100*desired_version_counts[majority_desired_version]/sum(desired_version_counts.itervalues())))
 618
 619     if bitcoind_getinfo['errors'] != '':
 620         if 'This is a pre-release test build' not in bitcoind_getinfo['errors']:
 621             res.append('(from bitcoind) %s' % (bitcoind_getinfo['errors'],))
 622
 623     version_warning = getattr(net, 'VERSION_WARNING', lambda v: None)(bitcoind_getinfo['version'])
 624     if version_warning is not None:
 625         res.append(version_warning)
 626
 627     if time.time() > bitcoind_work_value['last_update'] + 60:
 628         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']),))
 629
 630     return res
 631
 632 def format_hash(x):
 633     if x is None:
 634         return 'xxxxxxxx'
 635     return '%08x' % (x % 2**32)
 636
 637 class ShareStore(object):
 638     def __init__(self, prefix, net, share_cb, verified_hash_cb):
 639         self.dirname = os.path.dirname(os.path.abspath(prefix))
 640         self.filename = os.path.basename(os.path.abspath(prefix))
 641         self.net = net
 642
 643         known = {}
 644         filenames, next = self.get_filenames_and_next()
 645         for filename in filenames:
 646             share_hashes, verified_hashes = known.setdefault(filename, (set(), set()))
 647             with open(filename, 'rb') as f:
 648                 for line in f:
 649                     try:
 650                         type_id_str, data_hex = line.strip().split(' ')
 651                         type_id = int(type_id_str)
 652                         if type_id == 0:
 653                             pass
 654                         elif type_id == 1:
 655                             pass
 656                         elif type_id == 2:
 657                             verified_hash = int(data_hex, 16)
 658                             verified_hash_cb(verified_hash)
 659                             verified_hashes.add(verified_hash)
 660                         elif type_id == 5:
 661                             raw_share = share_type.unpack(data_hex.decode('hex'))
 662                             if raw_share['type'] < Share.VERSION:
 663                                 continue
 664                             share = load_share(raw_share, self.net, None)
 665                             share_cb(share)
 666                             share_hashes.add(share.hash)
 667                         else:
 668                             raise NotImplementedError("share type %i" % (type_id,))
 669                     except Exception:
 670                         log.err(None, "HARMLESS error while reading saved shares, continuing where left off:")
 671
 672         self.known = known # filename -> (set of share hashes, set of verified hashes)
 673         self.known_desired = dict((k, (set(a), set(b))) for k, (a, b) in known.iteritems())
 674
 675     def _add_line(self, line):
 676         filenames, next = self.get_filenames_and_next()
 677         if filenames and os.path.getsize(filenames[-1]) < 10e6:
 678             filename = filenames[-1]
 679         else:
 680             filename = next
 681
 682         with open(filename, 'ab') as f:
 683             f.write(line + '\n')
 684
 685         return filename
 686
 687     def add_share(self, share):
 688         for filename, (share_hashes, verified_hashes) in self.known.iteritems():
 689             if share.hash in share_hashes:
 690                 break
 691         else:
 692             filename = self._add_line("%i %s" % (5, share_type.pack(share.as_share()).encode('hex')))
 693             share_hashes, verified_hashes = self.known.setdefault(filename, (set(), set()))
 694             share_hashes.add(share.hash)
 695         share_hashes, verified_hashes = self.known_desired.setdefault(filename, (set(), set()))
 696         share_hashes.add(share.hash)
 697
 698     def add_verified_hash(self, share_hash):
 699         for filename, (share_hashes, verified_hashes) in self.known.iteritems():
 700             if share_hash in verified_hashes:
 701                 break
 702         else:
 703             filename = self._add_line("%i %x" % (2, share_hash))
 704             share_hashes, verified_hashes = self.known.setdefault(filename, (set(), set()))
 705             verified_hashes.add(share_hash)
 706         share_hashes, verified_hashes = self.known_desired.setdefault(filename, (set(), set()))
 707         verified_hashes.add(share_hash)
 708
 709     def get_filenames_and_next(self):
 710         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())
 711         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)))
 712
 713     def forget_share(self, share_hash):
 714         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
 715             if share_hash in share_hashes:
 716                 share_hashes.remove(share_hash)
 717         self.check_remove()
 718
 719     def forget_verified_share(self, share_hash):
 720         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
 721             if share_hash in verified_hashes:
 722                 verified_hashes.remove(share_hash)
 723         self.check_remove()
 724
 725     def check_remove(self):
 726         to_remove = set()
 727         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
 728             #print filename, len(share_hashes) + len(verified_hashes)
 729             if not share_hashes and not verified_hashes:
 730                 to_remove.add(filename)
 731         for filename in to_remove:
 732             self.known.pop(filename)
 733             self.known_desired.pop(filename)
 734             os.remove(filename)
 735             print "REMOVED", filename