p2pool/data.py

   1 from __future__ import division
   2
   3 import itertools
   4 import random
   5 import time
   6
   7 from twisted.python import log
   8
   9 import p2pool
  10 from p2pool import skiplists
  11 from p2pool.bitcoin import data as bitcoin_data, script
  12 from p2pool.util import memoize, expiring_dict, math
  13
  14
  15 merkle_branch_type = bitcoin_data.ListType(bitcoin_data.ComposedType([
  16     ('side', bitcoin_data.StructType('<B')), # enum?
  17     ('hash', bitcoin_data.HashType()),
  18 ]))
  19
  20
  21 share_data_type = bitcoin_data.ComposedType([
  22     ('previous_share_hash', bitcoin_data.PossiblyNone(0, bitcoin_data.HashType())),
  23     ('target', bitcoin_data.FloatingIntegerType()),
  24     ('nonce', bitcoin_data.VarStrType()),
  25 ])
  26
  27
  28 coinbase_type = bitcoin_data.ComposedType([
  29     ('identifier', bitcoin_data.FixedStrType(8)),
  30     ('share_data', share_data_type),
  31 ])
  32
  33 share_info_type = bitcoin_data.ComposedType([
  34     ('share_data', share_data_type),
  35     ('new_script', bitcoin_data.VarStrType()),
  36     ('subsidy', bitcoin_data.StructType('<Q')),
  37 ])
  38
  39
  40 share1a_type = bitcoin_data.ComposedType([
  41     ('header', bitcoin_data.block_header_type),
  42     ('share_info', share_info_type),
  43     ('merkle_branch', merkle_branch_type),
  44 ])
  45
  46 share1b_type = bitcoin_data.ComposedType([
  47     ('header', bitcoin_data.block_header_type),
  48     ('share_info', share_info_type),
  49     ('other_txs', bitcoin_data.ListType(bitcoin_data.tx_type)),
  50 ])
  51
  52 def calculate_merkle_branch(txs, index):
  53     hash_list = [(bitcoin_data.tx_type.hash256(tx), i == index, []) for i, tx in enumerate(txs)]
  54
  55     while len(hash_list) > 1:
  56         hash_list = [
  57             (
  58                 bitcoin_data.merkle_record_type.hash256(dict(left=left, right=right)),
  59                 left_f or right_f,
  60                 (left_l if left_f else right_l) + [dict(side=1, hash=right) if left_f else dict(side=0, hash=left)],
  61             )
  62             for (left, left_f, left_l), (right, right_f, right_l) in
  63                 zip(hash_list[::2], hash_list[1::2] + [hash_list[::2][-1]])
  64         ]
  65
  66     assert hash_list[0][1]
  67     assert check_merkle_branch(txs[index], hash_list[0][2]) == hash_list[0][0]
  68
  69     return hash_list[0][2]
  70
  71 def check_merkle_branch(tx, branch):
  72     hash_ = bitcoin_data.tx_type.hash256(tx)
  73     for step in branch:
  74         if not step['side']:
  75             hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=step['hash'], right=hash_))
  76         else:
  77             hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=hash_, right=step['hash']))
  78     return hash_
  79
  80 def gentx_to_share_info(gentx):
  81     return dict(
  82         share_data=coinbase_type.unpack(gentx['tx_ins'][0]['script'])['share_data'],
  83         subsidy=sum(tx_out['value'] for tx_out in gentx['tx_outs']),
  84         new_script=gentx['tx_outs'][-1]['script'],
  85     )
  86
  87 def share_info_to_gentx(share_info, block_target, tracker, net):
  88     return generate_transaction(
  89         tracker=tracker,
  90         previous_share_hash=share_info['share_data']['previous_share_hash'],
  91         new_script=share_info['new_script'],
  92         subsidy=share_info['subsidy'],
  93         nonce=share_info['share_data']['nonce'],
  94         block_target=block_target,
  95         net=net,
  96     )
  97
  98 class Share(object):
  99     @classmethod
 100     def from_block(cls, block):
 101         return cls(block['header'], gentx_to_share_info(block['txs'][0]), other_txs=block['txs'][1:])
 102
 103     @classmethod
 104     def from_share1a(cls, share1a):
 105         return cls(**share1a)
 106
 107     @classmethod
 108     def from_share1b(cls, share1b):
 109         return cls(**share1b)
 110
 111     __slots__ = 'header previous_block share_info merkle_branch other_txs timestamp share_data new_script subsidy previous_hash previous_share_hash target nonce bitcoin_hash hash time_seen shared peer'.split(' ')
 112
 113     def __init__(self, header, share_info, merkle_branch=None, other_txs=None):
 114         if merkle_branch is None and other_txs is None:
 115             raise ValueError('need either merkle_branch or other_txs')
 116         if other_txs is not None:
 117             new_merkle_branch = calculate_merkle_branch([dict(version=0, tx_ins=[], tx_outs=[], lock_time=0)] + other_txs, 0)
 118             if merkle_branch is not None:
 119                 if merke_branch != new_merkle_branch:
 120                     raise ValueError('invalid merkle_branch and other_txs')
 121             merkle_branch = new_merkle_branch
 122
 123         if len(merkle_branch) > 16:
 124             raise ValueError('merkle_branch too long!')
 125
 126         self.header = header
 127         self.previous_block = header['previous_block']
 128         self.share_info = share_info
 129         self.merkle_branch = merkle_branch
 130         self.other_txs = other_txs
 131
 132         self.timestamp = self.header['timestamp']
 133
 134         self.share_data = self.share_info['share_data']
 135         self.new_script = self.share_info['new_script']
 136         self.subsidy = self.share_info['subsidy']
 137
 138         if len(self.new_script) > 100:
 139             raise ValueError('new_script too long!')
 140
 141         self.previous_hash = self.previous_share_hash = self.share_data['previous_share_hash']
 142         self.target = self.share_data['target']
 143         self.nonce = self.share_data['nonce']
 144
 145         if len(self.nonce) > 100:
 146             raise ValueError('nonce too long!')
 147
 148         self.bitcoin_hash = bitcoin_data.block_header_type.hash256(header)
 149         self.hash = share1a_type.hash256(self.as_share1a())
 150
 151         if self.bitcoin_hash > self.target:
 152             print 'hash', hex(self.bitcoin_hash)
 153             print 'targ', hex(self.target)
 154             raise ValueError('not enough work!')
 155
 156         if script.get_sigop_count(self.new_script) > 1:
 157             raise ValueError('too many sigops!')
 158
 159         # XXX eww
 160         self.time_seen = time.time()
 161         self.shared = False
 162         self.peer = None
 163
 164     def as_block(self, tracker, net):
 165         if self.other_txs is None:
 166             raise ValueError('share does not contain all txs')
 167
 168         gentx = share_info_to_gentx(self.share_info, self.header['target'], tracker, net)
 169
 170         return dict(header=self.header, txs=[gentx] + self.other_txs)
 171
 172     def as_share1a(self):
 173         return dict(header=self.header, share_info=self.share_info, merkle_branch=self.merkle_branch)
 174
 175     def as_share1b(self):
 176         return dict(header=self.header, share_info=self.share_info, other_txs=self.other_txs)
 177
 178     def check(self, tracker, now, net):
 179         import time
 180         if self.previous_share_hash is not None:
 181             if self.header['timestamp'] <= math.median((s.timestamp for s in itertools.islice(tracker.get_chain_to_root(self.previous_share_hash), 11)), use_float=False):
 182                 raise ValueError('share from too far in the past!')
 183
 184         if self.header['timestamp'] > now + 2*60*60:
 185             raise ValueError('share from too far in the future!')
 186
 187         gentx = share_info_to_gentx(self.share_info, self.header['target'], tracker, net)
 188
 189         if len(gentx['tx_ins'][0]['script']) > 100:
 190             raise ValueError('''coinbase too large!''')
 191
 192         if check_merkle_branch(gentx, self.merkle_branch) != self.header['merkle_root']:
 193             raise ValueError('''gentx doesn't match header via merkle_branch''')
 194
 195         if self.other_txs is not None:
 196             if bitcoin_data.merkle_hash([gentx] + self.other_txs) != self.header['merkle_root']:
 197                 raise ValueError('''gentx doesn't match header via other_txs''')
 198
 199             if len(bitcoin_data.block_type.pack(dict(header=self.header, txs=[gentx] + self.other_txs))) > 1000000 - 1000:
 200                 raise ValueError('''block size too large''')
 201
 202     def flag_shared(self):
 203         self.shared = True
 204
 205     def __repr__(self):
 206         return '<Share %s>' % (' '.join('%s=%r' % (k, v) for k, v in self.__dict__.iteritems()),)
 207
 208 def get_pool_attempts_per_second(tracker, previous_share_hash, net, dist=None):
 209     if dist is None:
 210         dist = net.TARGET_LOOKBEHIND
 211     near = tracker.shares[previous_share_hash]
 212     far = tracker.shares[tracker.get_nth_parent_hash(previous_share_hash, dist - 1)]
 213     attempts = tracker.get_work(near.hash) - tracker.get_work(far.hash)
 214     time = near.timestamp - far.timestamp
 215     if time == 0:
 216         time = 1
 217     return attempts//time
 218
 219 def generate_transaction(tracker, previous_share_hash, new_script, subsidy, nonce, block_target, net):
 220     height, last = tracker.get_height_and_last(previous_share_hash)
 221     if height < net.TARGET_LOOKBEHIND:
 222         target = bitcoin_data.FloatingIntegerType().truncate_to(2**256//2**20 - 1)
 223     else:
 224         attempts_per_second = get_pool_attempts_per_second(tracker, previous_share_hash, net)
 225         pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1
 226         previous_share = tracker.shares[previous_share_hash] if previous_share_hash is not None else None
 227         pre_target2 = math.clip(pre_target, (previous_share.target*9//10, previous_share.target*11//10))
 228         pre_target3 = math.clip(pre_target2, (0, net.MAX_TARGET))
 229         target = bitcoin_data.FloatingIntegerType().truncate_to(pre_target3)
 230
 231     attempts_to_block = bitcoin_data.target_to_average_attempts(block_target)
 232     max_weight = net.SPREAD * attempts_to_block
 233
 234     this_weight = min(bitcoin_data.target_to_average_attempts(target), max_weight)
 235     other_weights, other_weights_total = tracker.get_cumulative_weights(previous_share_hash, min(height, net.CHAIN_LENGTH), max(0, max_weight - this_weight))
 236     dest_weights, total_weight = math.add_dicts([{new_script: this_weight}, other_weights]), this_weight + other_weights_total
 237     assert total_weight == sum(dest_weights.itervalues())
 238
 239     amounts = dict((script, subsidy*(396*weight)//(400*total_weight)) for (script, weight) in dest_weights.iteritems())
 240     amounts[new_script] = amounts.get(new_script, 0) + subsidy*2//400
 241     amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy*2//400
 242     amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy - sum(amounts.itervalues()) # collect any extra
 243     if sum(amounts.itervalues()) != subsidy:
 244         raise ValueError()
 245     if any(x < 0 for x in amounts.itervalues()):
 246         raise ValueError()
 247
 248     pre_dests = sorted(amounts.iterkeys(), key=lambda script: (amounts[script], script))
 249     pre_dests = pre_dests[-4000:] # block length limit, unlikely to ever be hit
 250
 251     dests = sorted(pre_dests, key=lambda script: (script == new_script, script))
 252     assert dests[-1] == new_script
 253
 254     return dict(
 255         version=1,
 256         tx_ins=[dict(
 257             previous_output=None,
 258             sequence=None,
 259             script=coinbase_type.pack(dict(
 260                 identifier=net.IDENTIFIER,
 261                 share_data=dict(
 262                     previous_share_hash=previous_share_hash,
 263                     nonce=nonce,
 264                     target=target,
 265                 ),
 266             )),
 267         )],
 268         tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script]],
 269         lock_time=0,
 270     )
 271
 272
 273
 274 class OkayTracker(bitcoin_data.Tracker):
 275     def __init__(self, net):
 276         bitcoin_data.Tracker.__init__(self)
 277         self.net = net
 278         self.verified = bitcoin_data.Tracker()
 279
 280         self.get_cumulative_weights = skiplists.WeightsSkipList(self)
 281
 282     def add(self, share, known_verified=False):
 283         bitcoin_data.Tracker.add(self, share)
 284         if known_verified:
 285             self.verified.add(share)
 286
 287     def attempt_verify(self, share, now):
 288         if share.hash in self.verified.shares:
 289             return True
 290         height, last = self.get_height_and_last(share.hash)
 291         if height < self.net.CHAIN_LENGTH and last is not None:
 292             raise AssertionError()
 293         try:
 294             share.check(self, now, self.net)
 295         except:
 296             log.err(None, 'Share check failed:')
 297             return False
 298         else:
 299             self.verified.add(share)
 300             return True
 301
 302     def think(self, ht, previous_block, now):
 303         desired = set()
 304
 305         # O(len(self.heads))
 306         #   make 'unverified heads' set?
 307         # for each overall head, attempt verification
 308         # if it fails, attempt on parent, and repeat
 309         # if no successful verification because of lack of parents, request parent
 310         bads = set()
 311         for head in set(self.heads) - set(self.verified.heads):
 312             head_height, last = self.get_height_and_last(head)
 313
 314             for share in itertools.islice(self.get_chain_known(head), None if last is None else min(5, max(0, head_height - self.net.CHAIN_LENGTH))):
 315                 if self.attempt_verify(share, now):
 316                     break
 317                 if share.hash in self.heads:
 318                     bads.add(share.hash)
 319             else:
 320                 if last is not None:
 321                     desired.add((self.shares[random.choice(list(self.reverse_shares[last]))].peer, last))
 322         for bad in bads:
 323             assert bad not in self.verified.shares
 324             assert bad in self.heads
 325             self.remove(bad)
 326
 327         # try to get at least CHAIN_LENGTH height for each verified head, requesting parents if needed
 328         for head in list(self.verified.heads):
 329             head_height, last_hash = self.verified.get_height_and_last(head)
 330             last_height, last_last_hash = self.get_height_and_last(last_hash)
 331             # XXX review boundary conditions
 332             want = max(self.net.CHAIN_LENGTH - head_height, 0)
 333             can = max(last_height - 1 - self.net.CHAIN_LENGTH, 0) if last_last_hash is not None else last_height
 334             get = min(want, can)
 335             #print 'Z', head_height, last_hash is None, last_height, last_last_hash is None, want, can, get
 336             for share in itertools.islice(self.get_chain_known(last_hash), get):
 337                 if not self.attempt_verify(share, now):
 338                     break
 339             if head_height < self.net.CHAIN_LENGTH and last_last_hash is not None:
 340                 desired.add((self.verified.shares[random.choice(list(self.verified.reverse_shares[last_hash]))].peer, last_last_hash))
 341
 342         # decide best tree
 343         best_tail = max(self.verified.tails, key=lambda h: self.score(max(self.verified.tails[h], key=self.verified.get_height), ht)) if self.verified.tails else None
 344         # decide best verified head
 345         scores = sorted(self.verified.tails.get(best_tail, []), key=lambda h: (
 346             self.verified.get_work(self.verified.get_nth_parent_hash(h, min(5, self.verified.get_height(h)))),
 347             ht.get_min_height(self.verified.shares[h].previous_block),
 348             self.verified.shares[h].peer is None,
 349             -self.verified.shares[h].time_seen
 350         ))
 351
 352
 353         if p2pool.DEBUG:
 354             print len(self.verified.tails.get(best_tail, []))
 355             for h in scores:
 356                 print '   ', format_hash(h), format_hash(self.verified.shares[h].previous_hash), (
 357                     self.verified.get_work(self.verified.get_nth_parent_hash(h, min(5, self.verified.get_height(h)))),
 358                     ht.get_min_height(self.verified.shares[h].previous_block),
 359                     self.verified.shares[h].peer is None,
 360                     -self.verified.shares[h].time_seen
 361                 )
 362
 363         # eat away at heads
 364         if scores:
 365             while True:
 366                 to_remove = set()
 367                 for share_hash, tail in self.heads.iteritems():
 368                     if share_hash in scores[-5:]:
 369                         continue
 370                     if self.shares[share_hash].time_seen > time.time() - 30:
 371                         continue
 372                     if max(self.shares[before_tail_hash].time_seen for before_tail_hash in self.reverse_shares.get(tail)) > time.time() - 120:
 373                         continue
 374                     to_remove.add(share_hash)
 375                 for share_hash in to_remove:
 376                     self.remove(share_hash)
 377                     if share_hash in self.verified.shares:
 378                         self.verified.remove(share_hash)
 379                 if not to_remove:
 380                     break
 381
 382         # drop tails
 383         while True:
 384             removed = False
 385             # if removed from this, it must be removed from verified
 386             for tail, heads in list(self.tails.iteritems()):
 387                 if min(self.get_height(head) for head in heads) < 2*self.net.CHAIN_LENGTH + 10:
 388                     continue
 389                 start = time.time()
 390                 for aftertail in list(self.reverse_shares.get(tail, set())):
 391                     self.remove(aftertail)
 392                     if aftertail in self.verified.shares:
 393                         self.verified.remove(aftertail)
 394                     removed = True
 395                 end = time.time()
 396                 print "removed! %x %f" % (tail, end - start)
 397             if not removed:
 398                 break
 399
 400         best = scores[-1] if scores else None
 401
 402         if best is not None:
 403             best_share = self.verified.shares[best]
 404             if ht.get_min_height(best_share.header['previous_block']) < ht.get_min_height(previous_block) and best_share.bitcoin_hash != previous_block and best_share.peer is not None:
 405                 if p2pool.DEBUG:
 406                     print 'Stale detected!'
 407                 best = best_share.previous_hash
 408
 409         return best, desired
 410
 411     @memoize.memoize_with_backing(expiring_dict.ExpiringDict(5, get_touches=False))
 412     def score(self, share_hash, ht):
 413         head_height, last = self.verified.get_height_and_last(share_hash)
 414         score2 = 0
 415         attempts = 0
 416         max_height = 0
 417         share2_hash = self.verified.get_nth_parent_hash(share_hash, min(self.net.CHAIN_LENGTH//2, head_height//2)) if last is not None else share_hash
 418         for share in reversed(list(itertools.islice(self.verified.get_chain_known(share2_hash), self.net.CHAIN_LENGTH))):
 419             max_height = max(max_height, ht.get_min_height(share.header['previous_block']))
 420             attempts += bitcoin_data.target_to_average_attempts(share.target)
 421             this_score = attempts//(ht.get_highest_height() - max_height + 1)
 422             if this_score > score2:
 423                 score2 = this_score
 424         return min(head_height, self.net.CHAIN_LENGTH), score2
 425
 426 def format_hash(x):
 427     if x is None:
 428         return 'xxxxxxxx'
 429     return '%08x' % (x % 2**32)
 430
 431 class Mainnet(bitcoin_data.Mainnet):
 432     SHARE_PERIOD = 5 # seconds
 433     CHAIN_LENGTH = 24*60*60//5 # shares
 434     TARGET_LOOKBEHIND = 200 # shares
 435     SPREAD = 3 # blocks
 436     SCRIPT = '4104ffd03de44a6e11b9917f3a29f9443283d9871c9d743ef30d5eddcd37094b64d1b3d8090496b53256786bf5c82932ec23c3b74d9f05a6f95a8b5529352656664bac'.decode('hex')
 437     IDENTIFIER = 'fc70035c7a81bc6f'.decode('hex')
 438     PREFIX = '2472ef181efcd37b'.decode('hex')
 439     ADDRS_TABLE = 'addrs'
 440     P2P_PORT = 9333
 441     MAX_TARGET = 2**256//2**32 - 1
 442     PERSIST = True
 443     HEADERSTORE_FILENAME = 'headers.dat'
 444
 445 class Testnet(bitcoin_data.Testnet):
 446     SHARE_PERIOD = 1 # seconds
 447     CHAIN_LENGTH = 24*60*60//5 # shares
 448     TARGET_LOOKBEHIND = 200 # shares
 449     SPREAD = 3 # blocks
 450     SCRIPT = '410403ad3dee8ab3d8a9ce5dd2abfbe7364ccd9413df1d279bf1a207849310465b0956e5904b1155ecd17574778f9949589ebfd4fb33ce837c241474a225cf08d85dac'.decode('hex')
 451     IDENTIFIER = '5fc2be2d4f0d6bfb'.decode('hex')
 452     PREFIX = '3f6057a15036f441'.decode('hex')
 453     ADDRS_TABLE = 'addrs_testnet'
 454     P2P_PORT = 19333
 455     MAX_TARGET = 2**256//2**20 - 1
 456     PERSIST = False
 457     HEADERSTORE_FILENAME = 'testnet_headers.dat'