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
  14 merkle_branch_type = bitcoin_data.ListType(bitcoin_data.ComposedType([
  15     ('side', bitcoin_data.StructType('<B')), # enum?
  16     ('hash', bitcoin_data.HashType()),
  17 ]))
  18
  19
  20 share_data_type = bitcoin_data.ComposedType([
  21     ('previous_share_hash', bitcoin_data.PossiblyNone(0, bitcoin_data.HashType())),
  22     ('target', bitcoin_data.FloatingIntegerType()),
  23     ('nonce', bitcoin_data.VarStrType()),
  24 ])
  25
  26
  27 coinbase_type = bitcoin_data.ComposedType([
  28     ('identifier', bitcoin_data.FixedStrType(8)),
  29     ('share_data', share_data_type),
  30 ])
  31
  32 share_info_type = bitcoin_data.ComposedType([
  33     ('share_data', share_data_type),
  34     ('new_script', bitcoin_data.VarStrType()),
  35     ('subsidy', bitcoin_data.StructType('<Q')),
  36 ])
  37
  38
  39 share1a_type = bitcoin_data.ComposedType([
  40     ('header', bitcoin_data.block_header_type),
  41     ('share_info', share_info_type),
  42     ('merkle_branch', merkle_branch_type),
  43 ])
  44
  45 share1b_type = bitcoin_data.ComposedType([
  46     ('header', bitcoin_data.block_header_type),
  47     ('share_info', share_info_type),
  48     ('other_txs', bitcoin_data.ListType(bitcoin_data.tx_type)),
  49 ])
  50
  51 def calculate_merkle_branch(txs, index):
  52     hash_list = [(bitcoin_data.tx_type.hash256(tx), i == index, []) for i, tx in enumerate(txs)]
  53
  54     while len(hash_list) > 1:
  55         hash_list = [
  56             (
  57                 bitcoin_data.merkle_record_type.hash256(dict(left=left, right=right)),
  58                 left_f or right_f,
  59                 (left_l if left_f else right_l) + [dict(side=1, hash=right) if left_f else dict(side=0, hash=left)],
  60             )
  61             for (left, left_f, left_l), (right, right_f, right_l) in
  62                 zip(hash_list[::2], hash_list[1::2] + [hash_list[::2][-1]])
  63         ]
  64
  65     assert hash_list[0][1]
  66     assert check_merkle_branch(txs[index], hash_list[0][2]) == hash_list[0][0]
  67
  68     return hash_list[0][2]
  69
  70 def check_merkle_branch(tx, branch):
  71     hash_ = bitcoin_data.tx_type.hash256(tx)
  72     for step in branch:
  73         if not step['side']:
  74             hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=step['hash'], right=hash_))
  75         else:
  76             hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=hash_, right=step['hash']))
  77     return hash_
  78
  79 def gentx_to_share_info(gentx):
  80     return dict(
  81         share_data=coinbase_type.unpack(gentx['tx_ins'][0]['script'])['share_data'],
  82         subsidy=sum(tx_out['value'] for tx_out in gentx['tx_outs']),
  83         new_script=gentx['tx_outs'][-1]['script'],
  84     )
  85
  86 def share_info_to_gentx(share_info, block_target, tracker, net):
  87     return generate_transaction(
  88         tracker=tracker,
  89         previous_share_hash=share_info['share_data']['previous_share_hash'],
  90         new_script=share_info['new_script'],
  91         subsidy=share_info['subsidy'],
  92         nonce=share_info['share_data']['nonce'],
  93         block_target=block_target,
  94         net=net,
  95     )
  96
  97 class Share(object):
  98     peer = None
  99     highest_block_on_arrival = None
 100     gentx = None
 101
 102     @classmethod
 103     def from_block(cls, block):
 104         return cls(block['header'], gentx_to_share_info(block['txs'][0]), other_txs=block['txs'][1:])
 105
 106     @classmethod
 107     def from_share1a(cls, share1a):
 108         return cls(**share1a)
 109
 110     @classmethod
 111     def from_share1b(cls, share1b):
 112         return cls(**share1b)
 113
 114     def __init__(self, header, share_info, merkle_branch=None, other_txs=None):
 115         if merkle_branch is None and other_txs is None:
 116             raise ValueError('need either merkle_branch or other_txs')
 117         if other_txs is not None:
 118             new_merkle_branch = calculate_merkle_branch([dict(version=0, tx_ins=[], tx_outs=[], lock_time=0)] + other_txs, 0)
 119             if merkle_branch is not None:
 120                 if merke_branch != new_merkle_branch:
 121                     raise ValueError('invalid merkle_branch and other_txs')
 122             merkle_branch = new_merkle_branch
 123
 124         if len(merkle_branch) > 16:
 125             raise ValueError('merkle_branch too long!')
 126
 127         self.header = header
 128         self.previous_block = header['previous_block']
 129         self.share_info = share_info
 130         self.merkle_branch = merkle_branch
 131         self.other_txs = other_txs
 132
 133         self.timestamp = self.header['timestamp']
 134
 135         self.share_data = self.share_info['share_data']
 136         self.new_script = self.share_info['new_script']
 137         self.subsidy = self.share_info['subsidy']
 138
 139         if len(self.new_script) > 100:
 140             raise ValueError('new_script too long!')
 141
 142         self.previous_hash = self.previous_share_hash = self.share_data['previous_share_hash']
 143         self.target = self.share_data['target']
 144         self.nonce = self.share_data['nonce']
 145
 146         if len(self.nonce) > 20:
 147             raise ValueError('nonce too long!')
 148
 149         self.bitcoin_hash = bitcoin_data.block_header_type.hash256(header)
 150         self.hash = share1a_type.hash256(self.as_share1a())
 151
 152         if self.bitcoin_hash > self.target:
 153             print 'hash', hex(self.bitcoin_hash)
 154             print 'targ', hex(self.target)
 155             raise ValueError('not enough work!')
 156
 157         if script.get_sigop_count(self.new_script) > 1:
 158             raise ValueError('too many sigops!')
 159
 160         self.time_seen = time.time()
 161         self.shared = False
 162
 163     def as_block(self):
 164         if self.other_txs is None:
 165             raise ValueError('share does not contain all txs')
 166
 167         return dict(header=self.header, txs=[self.gentx] + self.other_txs)
 168
 169     def as_share1a(self):
 170         return dict(header=self.header, share_info=self.share_info, merkle_branch=self.merkle_branch)
 171
 172     def as_share1b(self):
 173         return dict(header=self.header, share_info=self.share_info, other_txs=self.other_txs)
 174
 175     def check(self, tracker, now, net):
 176         import time
 177         if self.previous_share_hash is not None:
 178             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):
 179                 raise ValueError('share from too far in the past!')
 180
 181         if self.header['timestamp'] > now + 2*60*60:
 182             raise ValueError('share from too far in the future!')
 183
 184         gentx = share_info_to_gentx(self.share_info, self.header['target'], tracker, net)
 185
 186         if check_merkle_branch(gentx, self.merkle_branch) != self.header['merkle_root']:
 187             raise ValueError('''gentx doesn't match header via merkle_branch''')
 188
 189         if self.other_txs is not None:
 190             if bitcoin_data.merkle_hash([gentx] + self.other_txs) != self.header['merkle_root']:
 191                 raise ValueError('''gentx doesn't match header via other_txs''')
 192
 193             if len(bitcoin_data.block_type.pack(dict(header=self.header, txs=[gentx] + self.other_txs))) > 1000000 - 1000:
 194                 raise ValueError('''block size too large''')
 195
 196         self.gentx = gentx
 197
 198     def flag_shared(self):
 199         self.shared = True
 200
 201     def __repr__(self):
 202         return '<Share %s>' % (' '.join('%s=%r' % (k, v) for k, v in self.__dict__.iteritems()),)
 203
 204 def get_pool_attempts_per_second(tracker, previous_share_hash, net):
 205     chain = list(itertools.islice(tracker.get_chain_to_root(previous_share_hash), net.TARGET_LOOKBEHIND))
 206     attempts = sum(bitcoin_data.target_to_average_attempts(share.target) for share in chain[:-1])
 207     time = chain[0].timestamp - chain[-1].timestamp
 208     if time == 0:
 209         time = 1
 210     return attempts//time
 211
 212 def generate_transaction(tracker, previous_share_hash, new_script, subsidy, nonce, block_target, net):
 213     if __debug__:
 214         print "start generate_transaction"
 215     height, last = tracker.get_height_and_last(previous_share_hash)
 216     if height < net.TARGET_LOOKBEHIND:
 217         target = bitcoin_data.FloatingIntegerType().truncate_to(2**256//2**20 - 1)
 218     else:
 219         attempts_per_second = get_pool_attempts_per_second(tracker, previous_share_hash, net)
 220         pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1
 221         previous_share = tracker.shares[previous_share_hash] if previous_share_hash is not None else None
 222         pre_target2 = math.clip(pre_target, (previous_share.target*9//10, previous_share.target*11//10))
 223         pre_target3 = math.clip(pre_target2, (0, 2**256//2**32 - 1))
 224         target = bitcoin_data.FloatingIntegerType().truncate_to(pre_target3)
 225
 226     attempts_to_block = bitcoin_data.target_to_average_attempts(block_target)
 227     max_weight = net.SPREAD * attempts_to_block
 228
 229     '''
 230     class fake_share(object):
 231         pass
 232     fake_share.new_script = new_script
 233     fake_share.target = target
 234
 235     dest_weights = {}
 236     total_weight = 0
 237     for share in itertools.chain([fake_share], itertools.islice(tracker.get_chain_to_root(previous_share_hash), net.CHAIN_LENGTH)):
 238         weight = bitcoin_data.target_to_average_attempts(share.target)
 239         if weight > max_weight - total_weight:
 240             weight = max_weight - total_weight
 241
 242         dest_weights[share.new_script] = dest_weights.get(share.new_script, 0) + weight
 243         total_weight += weight
 244
 245         if total_weight == max_weight:
 246             break
 247     '''
 248
 249     this_weight = min(bitcoin_data.target_to_average_attempts(target), max_weight)
 250     other_weights, other_weights_total = tracker.get_cumulative_weights(previous_share_hash, min(height, net.CHAIN_LENGTH), max(0, max_weight - this_weight))
 251     dest_weights, total_weight = math.add_dicts([{new_script: this_weight}, other_weights]), this_weight + other_weights_total
 252     total_weight = sum(dest_weights.itervalues())
 253
 254     amounts = dict((script, subsidy*(396*weight)//(400*total_weight)) for (script, weight) in dest_weights.iteritems())
 255     amounts[new_script] = amounts.get(new_script, 0) + subsidy*2//400
 256     amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy*2//400
 257     amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy - sum(amounts.itervalues()) # collect any extra
 258     if sum(amounts.itervalues()) != subsidy:
 259         raise ValueError()
 260     if any(x < 0 for x in amounts.itervalues()):
 261         raise ValueError()
 262
 263     pre_dests = sorted(amounts.iterkeys(), key=lambda script: (amounts[script], script))
 264     pre_dests = pre_dests[-4000:] # block length limit, unlikely to ever be hit
 265
 266     dests = sorted(pre_dests, key=lambda script: (script == new_script, script))
 267     assert dests[-1] == new_script
 268
 269     if __debug__:
 270         print "end generate_transaction"
 271
 272     return dict(
 273         version=1,
 274         tx_ins=[dict(
 275             previous_output=None,
 276             sequence=None,
 277             script=coinbase_type.pack(dict(
 278                 identifier=net.IDENTIFIER,
 279                 share_data=dict(
 280                     previous_share_hash=previous_share_hash,
 281                     nonce=nonce,
 282                     target=target,
 283                 ),
 284             )),
 285         )],
 286         tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script]],
 287         lock_time=0,
 288     )
 289
 290
 291
 292 class OkayTracker(bitcoin_data.Tracker):
 293     def __init__(self, net):
 294         bitcoin_data.Tracker.__init__(self)
 295         self.net = net
 296         self.verified = bitcoin_data.Tracker()
 297
 298         self.get_cumulative_weights = skiplist.WeightsSkipList(self)
 299
 300     def attempt_verify(self, share, now):
 301         if share.hash in self.verified.shares:
 302             return True
 303         height, last = self.get_height_and_last(share.hash)
 304         if height < self.net.CHAIN_LENGTH and last is not None:
 305             raise AssertionError()
 306         try:
 307             share.check(self, now, self.net)
 308         except:
 309             print
 310             print 'Share check failed:'
 311             log.err()
 312             print
 313             return False
 314         else:
 315             self.verified.add(share)
 316             return True
 317
 318     def think(self, ht, previous_block, now):
 319         if __debug__:
 320             print "start think"
 321
 322         desired = set()
 323
 324         # O(len(self.heads))
 325         #   make 'unverified heads' set?
 326         # for each overall head, attempt verification
 327         # if it fails, attempt on parent, and repeat
 328         # if no successful verification because of lack of parents, request parent
 329         bads = set()
 330         for head in set(self.heads) - set(self.verified.heads):
 331             head_height, last = self.get_height_and_last(head)
 332
 333             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))):
 334                 if self.attempt_verify(share, now):
 335                     break
 336                 if share.hash in self.heads:
 337                     bads.add(share.hash)
 338             else:
 339                 if last is not None:
 340                     desired.add((self.shares[random.choice(list(self.reverse_shares[last]))].peer, last))
 341         for bad in bads:
 342             assert bad not in self.verified.shares
 343             assert bad in self.heads
 344             self.remove(bad)
 345
 346         # try to get at least CHAIN_LENGTH height for each verified head, requesting parents if needed
 347         for head in list(self.verified.heads):
 348             head_height, last_hash = self.verified.get_height_and_last(head)
 349             last_height, last_last_hash = self.get_height_and_last(last_hash)
 350             # XXX review boundary conditions
 351             want = max(self.net.CHAIN_LENGTH - head_height, 0)
 352             can = max(last_height - 1 - self.net.CHAIN_LENGTH, 0) if last_last_hash is not None else last_height
 353             get = min(want, can)
 354             #print 'Z', head_height, last_hash is None, last_height, last_last_hash is None, want, can, get
 355             for share in itertools.islice(self.get_chain_known(last_hash), get):
 356                 if not self.attempt_verify(share, now):
 357                     break
 358             if head_height < self.net.CHAIN_LENGTH and last_last_hash is not None:
 359                 desired.add((self.verified.shares[random.choice(list(self.verified.reverse_shares[last_hash]))].peer, last_last_hash))
 360
 361         # decide best tree
 362         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
 363         # decide best verified head
 364         scores = sorted(self.verified.tails.get(best_tail, []), key=lambda h: (self.verified.get_work(h), ht.get_min_height(self.verified.shares[h].previous_block), -self.verified.shares[h].time_seen))
 365
 366
 367         #if __debug__:
 368             #print len(self.verified.tails.get(best_tail, []))
 369             #for a in scores:
 370             #    print '   ', '%x'%a, self.score(a, ht)
 371
 372         for share_hash in scores[:-5]:
 373             if self.shares[share_hash].time_seen > time.time() - 30:
 374                 continue
 375             self.remove(share_hash)
 376             self.verified.remove(share_hash)
 377
 378         best = scores[-1] if scores else None
 379
 380         if best is not None:
 381             best_share = self.verified.shares[best]
 382             if ht.get_min_height(best_share.header['previous_block']) < ht.get_min_height(previous_block) and best_share.peer is not None:
 383                 if __debug__:
 384                     print "stale detected!"
 385                 best = best_share.previous_hash
 386
 387         if __debug__:
 388             print "end think"
 389
 390         return best, desired
 391
 392     @memoize.memoize_with_backing(expiring_dict.ExpiringDict(5, get_touches=False))
 393     def score(self, share_hash, ht):
 394         head_height, last = self.verified.get_height_and_last(share_hash)
 395         score2 = 0
 396         attempts = 0
 397         max_height = 0
 398         # XXX should only look past a certain share, not at recent ones
 399         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
 400         # XXX this must go in the opposite direction for max_height to make sense
 401         for share in reversed(list(itertools.islice(self.verified.get_chain_known(share2_hash), self.net.CHAIN_LENGTH))):
 402             max_height = max(max_height, ht.get_min_height(share.header['previous_block']))
 403             attempts += bitcoin_data.target_to_average_attempts(share.target)
 404             this_score = attempts//(ht.get_highest_height() - max_height + 1)
 405             if this_score > score2:
 406                 score2 = this_score
 407         return min(head_height, self.net.CHAIN_LENGTH), score2
 408
 409
 410 class Mainnet(bitcoin_data.Mainnet):
 411     SHARE_PERIOD = 5 # seconds
 412     CHAIN_LENGTH = 24*60*60//5 # shares
 413     TARGET_LOOKBEHIND = 200 # shares
 414     SPREAD = 3 # blocks
 415     SCRIPT = '4104ffd03de44a6e11b9917f3a29f9443283d9871c9d743ef30d5eddcd37094b64d1b3d8090496b53256786bf5c82932ec23c3b74d9f05a6f95a8b5529352656664bac'.decode('hex')
 416     IDENTIFIER = 'fc70035c7a81bc6f'.decode('hex')
 417     PREFIX = '2472ef181efcd37b'.decode('hex')
 418     ADDRS_TABLE = 'addrs'
 419     P2P_PORT = 9333
 420
 421 class Testnet(bitcoin_data.Testnet):
 422     SHARE_PERIOD = 1 # seconds
 423     CHAIN_LENGTH = 24*60*60//5 # shares
 424     TARGET_LOOKBEHIND = 200 # shares
 425     SPREAD = 3 # blocks
 426     SCRIPT = '410403ad3dee8ab3d8a9ce5dd2abfbe7364ccd9413df1d279bf1a207849310465b0956e5904b1155ecd17574778f9949589ebfd4fb33ce837c241474a225cf08d85dac'.decode('hex')
 427     IDENTIFIER = '5fc2be5d4f0d6bfb'.decode('hex')
 428     PREFIX = '3f6057a15076f441'.decode('hex')
 429     ADDRS_TABLE = 'addrs_testnet'
 430     P2P_PORT = 19333