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 from p2pool.bitcoin import data as bitcoin_data
  10 from p2pool.bitcoin import script
  11 from p2pool.util import memoize, expiring_dict, math, skiplist
  12
  13 class CompressedList(bitcoin_data.Type):
  14     def __init__(self, inner):
  15         self.inner = inner
  16
  17     def read(self, file):
  18         values, file = bitcoin_data.ListType(self.inner).read(file)
  19         if values != sorted(set(values)):
  20             raise ValueError('invalid values')
  21         references, file = bitcoin_data.ListType(bitcoin_data.VarIntType()).read(file)
  22         return [values[reference] for reference in references], file
  23
  24     def write(self, file, item):
  25         values = sorted(set(item))
  26         values_map = dict((value, i) for i, value in enumerate(values))
  27         file = bitcoin_data.ListType(self.inner).write(file, values)
  28         return bitcoin_data.ListType(bitcoin_data.VarIntType()).write(file, [values_map[subitem] for subitem in item])
  29
  30
  31 merkle_branch_type = bitcoin_data.ListType(bitcoin_data.ComposedType([
  32     ('side', bitcoin_data.StructType('<B')), # enum?
  33     ('hash', bitcoin_data.HashType()),
  34 ]))
  35
  36
  37 share_data_type = bitcoin_data.ComposedType([
  38     ('previous_share_hash', bitcoin_data.PossiblyNone(0, bitcoin_data.HashType())),
  39     ('target2', bitcoin_data.FloatingIntegerType()),
  40     ('nonce', bitcoin_data.VarStrType()),
  41 ])
  42
  43
  44 coinbase_type = bitcoin_data.ComposedType([
  45     ('identifier', bitcoin_data.FixedStrType(8)),
  46     ('share_data', share_data_type),
  47 ])
  48
  49 share_info_type = bitcoin_data.ComposedType([
  50     ('share_data', share_data_type),
  51     ('new_script', bitcoin_data.VarStrType()),
  52     ('subsidy', bitcoin_data.StructType('<Q')),
  53 ])
  54
  55
  56 share1a_type = bitcoin_data.ComposedType([
  57     ('header', bitcoin_data.block_header_type),
  58     ('share_info', share_info_type),
  59     ('merkle_branch', merkle_branch_type),
  60 ])
  61
  62 share1b_type = bitcoin_data.ComposedType([
  63     ('header', bitcoin_data.block_header_type),
  64     ('share_info', share_info_type),
  65     ('other_txs', bitcoin_data.ListType(bitcoin_data.tx_type)),
  66 ])
  67
  68 shares_type = CompressedList(bitcoin_data.VarStrType())
  69
  70 def calculate_merkle_branch(txs, index):
  71     hash_list = [(bitcoin_data.tx_type.hash256(tx), i == index, []) for i, tx in enumerate(txs)]
  72
  73     while len(hash_list) > 1:
  74         hash_list = [
  75             (
  76                 bitcoin_data.merkle_record_type.hash256(dict(left=left, right=right)),
  77                 left_f or right_f,
  78                 (left_l if left_f else right_l) + [dict(side=1, hash=right) if left_f else dict(side=0, hash=left)],
  79             )
  80             for (left, left_f, left_l), (right, right_f, right_l) in
  81                 zip(hash_list[::2], hash_list[1::2] + [hash_list[::2][-1]])
  82         ]
  83
  84     assert hash_list[0][1]
  85     assert check_merkle_branch(txs[index], hash_list[0][2]) == hash_list[0][0]
  86
  87     return hash_list[0][2]
  88
  89 def check_merkle_branch(tx, branch):
  90     hash_ = bitcoin_data.tx_type.hash256(tx)
  91     for step in branch:
  92         if not step['side']:
  93             hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=step['hash'], right=hash_))
  94         else:
  95             hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=hash_, right=step['hash']))
  96     return hash_
  97
  98 def gentx_to_share_info(gentx):
  99     return dict(
 100         share_data=coinbase_type.unpack(gentx['tx_ins'][0]['script'])['share_data'],
 101         subsidy=sum(tx_out['value'] for tx_out in gentx['tx_outs']),
 102         new_script=gentx['tx_outs'][-1]['script'],
 103     )
 104
 105 def share_info_to_gentx(share_info, block_target, tracker, net):
 106     return generate_transaction(
 107         tracker=tracker,
 108         previous_share_hash=share_info['share_data']['previous_share_hash'],
 109         new_script=share_info['new_script'],
 110         subsidy=share_info['subsidy'],
 111         nonce=share_info['share_data']['nonce'],
 112         block_target=block_target,
 113         net=net,
 114     )
 115
 116 class Share(object):
 117     peer = None
 118     gentx = None
 119
 120     @classmethod
 121     def from_block(cls, block):
 122         return cls(block['header'], gentx_to_share_info(block['txs'][0]), other_txs=block['txs'][1:])
 123
 124     @classmethod
 125     def from_share1a(cls, share1a):
 126         return cls(**share1a)
 127
 128     @classmethod
 129     def from_share1b(cls, share1b):
 130         return cls(**share1b)
 131
 132     def __init__(self, header, share_info, merkle_branch=None, other_txs=None):
 133         if merkle_branch is None and other_txs is None:
 134             raise ValueError('need either merkle_branch or other_txs')
 135         if other_txs is not None:
 136             new_merkle_branch = calculate_merkle_branch([dict(version=0, tx_ins=[], tx_outs=[], lock_time=0)] + other_txs, 0)
 137             if merkle_branch is not None:
 138                 if merke_branch != new_merkle_branch:
 139                     raise ValueError('invalid merkle_branch and other_txs')
 140             merkle_branch = new_merkle_branch
 141
 142         if len(merkle_branch) > 16:
 143             raise ValueError('merkle_branch too long!')
 144
 145         self.header = header
 146         self.share_info = share_info
 147         self.merkle_branch = merkle_branch
 148         self.other_txs = other_txs
 149
 150         self.timestamp = self.header['timestamp']
 151
 152         self.share_data = self.share_info['share_data']
 153         self.new_script = self.share_info['new_script']
 154         self.subsidy = self.share_info['subsidy']
 155
 156         if len(self.new_script) > 100:
 157             raise ValueError('new_script too long!')
 158
 159         self.previous_hash = self.previous_share_hash = self.share_data['previous_share_hash']
 160         self.target2 = self.share_data['target2']
 161         self.nonce = self.share_data['nonce']
 162
 163         if len(self.nonce) > 20:
 164             raise ValueError('nonce too long!')
 165
 166         self.hash = bitcoin_data.block_header_type.hash256(header)
 167
 168         if self.hash > self.target2:
 169             print 'hash', hex(self.hash)
 170             print 'targ', hex(self.target2)
 171             raise ValueError('not enough work!')
 172
 173         if script.get_sigop_count(self.new_script) > 1:
 174             raise ValueError('too many sigops!')
 175
 176         self.time_seen = time.time()
 177         self.shared = False
 178
 179     def as_block(self):
 180         if self.other_txs is None:
 181             raise ValueError('share does not contain all txs')
 182
 183         return dict(header=self.header, txs=[self.gentx] + self.other_txs)
 184
 185     def as_share1a(self):
 186         return dict(header=self.header, share_info=self.share_info, merkle_branch=self.merkle_branch)
 187
 188     def as_share1b(self):
 189         return dict(header=self.header, share_info=self.share_info, other_txs=self.other_txs)
 190
 191     def check(self, tracker, now, net):
 192         import time
 193         if self.previous_share_hash is not None:
 194             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):
 195                 raise ValueError('share from too far in the past!')
 196
 197         if self.header['timestamp'] > now + 2*60*60:
 198             raise ValueError('share from too far in the future!')
 199
 200         gentx = share_info_to_gentx(self.share_info, self.header['target'], tracker, net)
 201
 202         if check_merkle_branch(gentx, self.merkle_branch) != self.header['merkle_root']:
 203             raise ValueError('''gentx doesn't match header via merkle_branch''')
 204
 205         if self.other_txs is not None:
 206             if bitcoin_data.merkle_hash([gentx] + self.other_txs) != self.header['merkle_root']:
 207                 raise ValueError('''gentx doesn't match header via other_txs''')
 208
 209             if len(bitcoin_data.block_type.pack(dict(header=self.header, txs=[gentx] + self.other_txs))) > 1000000 - 1000:
 210                 raise ValueError('''block size too large''')
 211
 212         self.gentx = gentx
 213
 214         return Share2(self)
 215
 216     def flag_shared(self):
 217         self.shared = True
 218
 219     def __repr__(self):
 220         return '<Share %s>' % (' '.join('%s=%r' % (k, v) for k, v in self.__dict__.iteritems()),)
 221
 222 class Share2(object):
 223     '''Share with associated data'''
 224
 225     def __init__(self, share):
 226         self.share = share
 227
 228         self.shared = False
 229
 230     def flag_shared(self):
 231         self.shared = True
 232
 233 def get_pool_attempts_per_second(tracker, previous_share_hash, net):
 234     chain = list(itertools.islice(tracker.get_chain_to_root(previous_share_hash), net.TARGET_LOOKBEHIND))
 235     attempts = sum(bitcoin_data.target_to_average_attempts(share.target2) for share in chain[:-1])
 236     time = chain[0].timestamp - chain[-1].timestamp
 237     if time == 0:
 238         time = 1
 239     return attempts//time
 240
 241 def generate_transaction(tracker, previous_share_hash, new_script, subsidy, nonce, block_target, net):
 242     if __debug__:
 243         print "start generate_transaction"
 244     height, last = tracker.get_height_and_last(previous_share_hash)
 245     if height < net.TARGET_LOOKBEHIND:
 246         target2 = bitcoin_data.FloatingIntegerType().truncate_to(2**256//2**20 - 1)
 247     else:
 248         attempts_per_second = get_pool_attempts_per_second(tracker, previous_share_hash, net)
 249         pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1
 250         previous_share = tracker.shares[previous_share_hash] if previous_share_hash is not None else None
 251         pre_target2 = math.clip(pre_target, (previous_share.target2*9//10, previous_share.target2*11//10))
 252         pre_target3 = math.clip(pre_target2, (0, 2**256//2**32 - 1))
 253         target2 = bitcoin_data.FloatingIntegerType().truncate_to(pre_target3)
 254
 255     attempts_to_block = bitcoin_data.target_to_average_attempts(block_target)
 256     max_weight = net.SPREAD * attempts_to_block
 257
 258     '''
 259     class fake_share(object):
 260         pass
 261     fake_share.new_script = new_script
 262     fake_share.target2 = target2
 263
 264     dest_weights = {}
 265     total_weight = 0
 266     for share in itertools.chain([fake_share], itertools.islice(tracker.get_chain_to_root(previous_share_hash), net.CHAIN_LENGTH)):
 267         weight = bitcoin_data.target_to_average_attempts(share.target2)
 268         if weight > max_weight - total_weight:
 269             weight = max_weight - total_weight
 270
 271         dest_weights[share.new_script] = dest_weights.get(share.new_script, 0) + weight
 272         total_weight += weight
 273
 274         if total_weight == max_weight:
 275             break
 276     '''
 277
 278     this_weight = min(bitcoin_data.target_to_average_attempts(target2), max_weight)
 279     dest_weights = math.add_dicts([{new_script: this_weight}, tracker.get_cumulative_weights(previous_share_hash, min(tracker.get_height_and_last(previous_share_hash)[0], net.CHAIN_LENGTH), max(0, max_weight - this_weight))[0]])
 280     total_weight = sum(dest_weights.itervalues())
 281     #assert dest_weights == dest_weights2
 282
 283     amounts = dict((script, subsidy*(198*weight)//(200*total_weight)) for (script, weight) in dest_weights.iteritems())
 284     amounts[net_script] = amounts.get(new_script, 0) + subsidy*1//200
 285     amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy*1//200
 286     amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy - sum(amounts.itervalues()) # collect any extra
 287     if sum(amounts.itervalues()) != subsidy:
 288         raise ValueError()
 289     if any(x < 0 for x in amounts.itervalues()):
 290         raise ValueError()
 291
 292     pre_dests = sorted(amounts.iterkeys(), key=lambda script: (amounts[script], script))
 293     pre_dests = pre_dests[-4000:] # block length limit, unlikely to ever be hit
 294
 295     dests = sorted(pre_dests, key=lambda script: (script == new_script, script))
 296     assert dests[-1] == new_script
 297
 298     if __debug__:
 299         print "end generate_transaction"
 300
 301     return dict(
 302         version=1,
 303         tx_ins=[dict(
 304             previous_output=None,
 305             sequence=None,
 306             script=coinbase_type.pack(dict(
 307                 identifier=net.IDENTIFIER,
 308                 share_data=dict(
 309                     previous_share_hash=previous_share_hash,
 310                     nonce=nonce,
 311                     target2=target2,
 312                 ),
 313             )),
 314         )],
 315         tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script]],
 316         lock_time=0,
 317     )
 318
 319
 320
 321 class OkayTracker(bitcoin_data.Tracker):
 322     def __init__(self, net):
 323         bitcoin_data.Tracker.__init__(self)
 324         self.net = net
 325         self.verified = bitcoin_data.Tracker()
 326
 327         self.get_cumulative_weights = skiplist.WeightsSkipList(self)
 328
 329     def attempt_verify(self, share, now):
 330         if share.hash in self.verified.shares:
 331             return True
 332         height, last = self.get_height_and_last(share.hash)
 333         if height < self.net.CHAIN_LENGTH and last is not None:
 334             raise AssertionError()
 335         try:
 336             share.check(self, now, self.net)
 337         except:
 338             print
 339             print 'Share check failed:'
 340             log.err()
 341             print
 342             return False
 343         else:
 344             self.verified.add(share)
 345             return True
 346
 347     def think(self, ht, now):
 348         if __debug__:
 349             print "start think"
 350
 351         desired = set()
 352
 353         # O(len(self.heads))
 354         #   make 'unverified heads' set?
 355         # for each overall head, attempt verification
 356         # if it fails, attempt on parent, and repeat
 357         # if no successful verification because of lack of parents, request parent
 358         bads = set()
 359         for head in set(self.heads) - set(self.verified.heads):
 360             head_height, last = self.get_height_and_last(head)
 361
 362             for share in itertools.islice(self.get_chain_known(head), None if last is None else max(0, head_height - self.net.CHAIN_LENGTH)):
 363                 if self.attempt_verify(share, now):
 364                     break
 365                 if share.hash in self.heads:
 366                     bads.add(share.hash)
 367             else:
 368                 if last is not None:
 369                     desired.add((self.shares[random.choice(list(self.reverse_shares[last]))].peer, last))
 370         for bad in bads:
 371             assert bad not in self.verified.shares
 372             assert bad in self.heads
 373             self.remove(bad)
 374
 375         # try to get at least CHAIN_LENGTH height for each verified head, requesting parents if needed
 376         for head in list(self.verified.heads):
 377             head_height, last_hash = self.verified.get_height_and_last(head)
 378             last_height, last_last_hash = self.get_height_and_last(last_hash)
 379             # XXX review boundary conditions
 380             want = max(self.net.CHAIN_LENGTH - head_height, 0)
 381             can = max(last_height - 1 - self.net.CHAIN_LENGTH, 0) if last_last_hash is not None else last_height
 382             get = min(want, can)
 383             #print 'Z', head_height, last_hash is None, last_height, last_last_hash is None, want, can, get
 384             for share in itertools.islice(self.get_chain_known(last_hash), get):
 385                 if not self.attempt_verify(share, now):
 386                     break
 387             if head_height < self.net.CHAIN_LENGTH and last_last_hash is not None:
 388                 desired.add((self.verified.shares[random.choice(list(self.verified.reverse_shares[last_hash]))].peer, last_last_hash))
 389
 390         # decide best verified head
 391         scores = sorted(self.verified.heads, key=lambda h: self.score(h, ht))
 392
 393         if __debug__:
 394             for a in scores:
 395                 print '   ', '%x'%a, self.score(a, ht)
 396
 397         for share_hash in scores[:-5]:
 398             if self.shares[share_hash].time_seen > time.time() - 30:
 399                 continue
 400             self.remove(share_hash)
 401             self.verified.remove(share_hash)
 402
 403         best = scores[-1] if scores else None
 404
 405         if __debug__:
 406             print "end think"
 407
 408         return best, desired
 409
 410     @memoize.memoize_with_backing(expiring_dict.ExpiringDict(5, get_touches=False))
 411     def score(self, share_hash, ht):
 412         head_height, last = self.verified.get_height_and_last(share_hash)
 413         score2 = 0
 414         attempts = 0
 415         max_height = 0
 416         # XXX should only look past a certain share, not at recent ones
 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         # XXX this must go in the opposite direction for max_height to make sense
 419         for share in reversed(list(itertools.islice(self.verified.get_chain_known(share2_hash), self.net.CHAIN_LENGTH))):
 420             max_height = max(max_height, ht.get_min_height(share.header['previous_block']))
 421             attempts += bitcoin_data.target_to_average_attempts(share.target2)
 422             this_score = attempts//(ht.get_highest_height() - max_height + 1)
 423             #this_score = -(ht.get_highest_height() - max_height + 1)//attempts
 424             if this_score > score2:
 425                 score2 = this_score
 426         res = (min(head_height, self.net.CHAIN_LENGTH), score2, -self.verified.shares[share_hash].time_seen)
 427         #print res
 428         return res
 429
 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 = '7452839666e1f8f8'.decode('hex')
 438     PREFIX = '2d4224bf18c87b87'.decode('hex')
 439     ADDRS_TABLE = 'addrs'
 440     P2P_PORT = 9333
 441
 442 class Testnet(bitcoin_data.Testnet):
 443     SHARE_PERIOD = 1 # seconds
 444     CHAIN_LENGTH = 24*60*60//5 # shares
 445     TARGET_LOOKBEHIND = 200 # shares
 446     SPREAD = 3 # blocks
 447     SCRIPT = '410403ad3dee8ab3d8a9ce5dd2abfbe7364ccd9413df1d279bf1a207849310465b0956e5904b1155ecd17574778f9949589ebfd4fb33ce837c241474a225cf08d85dac'.decode('hex')
 448     IDENTIFIER = '1ae3479e4eb6700a'.decode('hex')
 449     PREFIX = 'd19778c812754854'.decode('hex')
 450     ADDRS_TABLE = 'addrs_testnet'
 451     P2P_PORT = 19333