p2pool/data.py

   1 from __future__ import division
   2
   3 import itertools
   4 import random
   5 import time
   6
   7 from twisted.internet import defer
   8 from twisted.python import log
   9
  10 from p2pool.bitcoin import data as bitcoin_data
  11 from p2pool.bitcoin import script
  12 from p2pool.util import memoize, expiring_dict, math, skiplist, deferral
  13 import p2pool
  14
  15
  16 merkle_branch_type = bitcoin_data.ListType(bitcoin_data.ComposedType([
  17     ('side', bitcoin_data.StructType('<B')), # enum?
  18     ('hash', bitcoin_data.HashType()),
  19 ]))
  20
  21
  22 share_data_type = bitcoin_data.ComposedType([
  23     ('previous_share_hash', bitcoin_data.PossiblyNone(0, bitcoin_data.HashType())),
  24     ('target', bitcoin_data.FloatingIntegerType()),
  25     ('nonce', bitcoin_data.VarStrType()),
  26 ])
  27
  28
  29 coinbase_type = bitcoin_data.ComposedType([
  30     ('identifier', bitcoin_data.FixedStrType(8)),
  31     ('share_data', share_data_type),
  32 ])
  33
  34 share_info_type = bitcoin_data.ComposedType([
  35     ('share_data', share_data_type),
  36     ('new_script', bitcoin_data.VarStrType()),
  37     ('subsidy', bitcoin_data.StructType('<Q')),
  38 ])
  39
  40
  41 share1a_type = bitcoin_data.ComposedType([
  42     ('header', bitcoin_data.block_header_type),
  43     ('share_info', share_info_type),
  44     ('merkle_branch', merkle_branch_type),
  45 ])
  46
  47 share1b_type = bitcoin_data.ComposedType([
  48     ('header', bitcoin_data.block_header_type),
  49     ('share_info', share_info_type),
  50     ('other_txs', bitcoin_data.ListType(bitcoin_data.tx_type)),
  51 ])
  52
  53 def calculate_merkle_branch(txs, index):
  54     hash_list = [(bitcoin_data.tx_type.hash256(tx), i == index, []) for i, tx in enumerate(txs)]
  55
  56     while len(hash_list) > 1:
  57         hash_list = [
  58             (
  59                 bitcoin_data.merkle_record_type.hash256(dict(left=left, right=right)),
  60                 left_f or right_f,
  61                 (left_l if left_f else right_l) + [dict(side=1, hash=right) if left_f else dict(side=0, hash=left)],
  62             )
  63             for (left, left_f, left_l), (right, right_f, right_l) in
  64                 zip(hash_list[::2], hash_list[1::2] + [hash_list[::2][-1]])
  65         ]
  66
  67     assert hash_list[0][1]
  68     assert check_merkle_branch(txs[index], hash_list[0][2]) == hash_list[0][0]
  69
  70     return hash_list[0][2]
  71
  72 def check_merkle_branch(tx, branch):
  73     hash_ = bitcoin_data.tx_type.hash256(tx)
  74     for step in branch:
  75         if not step['side']:
  76             hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=step['hash'], right=hash_))
  77         else:
  78             hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=hash_, right=step['hash']))
  79     return hash_
  80
  81 def gentx_to_share_info(gentx):
  82     return dict(
  83         share_data=coinbase_type.unpack(gentx['tx_ins'][0]['script'])['share_data'],
  84         subsidy=sum(tx_out['value'] for tx_out in gentx['tx_outs']),
  85         new_script=gentx['tx_outs'][-1]['script'],
  86     )
  87
  88 def share_info_to_gentx(share_info, block_target, tracker, net):
  89     return generate_transaction(
  90         tracker=tracker,
  91         previous_share_hash=share_info['share_data']['previous_share_hash'],
  92         new_script=share_info['new_script'],
  93         subsidy=share_info['subsidy'],
  94         nonce=share_info['share_data']['nonce'],
  95         block_target=block_target,
  96         net=net,
  97     )
  98
  99 class Share(object):
 100     @classmethod
 101     def from_block(cls, block):
 102         return cls(block['header'], gentx_to_share_info(block['txs'][0]), other_txs=block['txs'][1:])
 103
 104     @classmethod
 105     def from_share1a(cls, share1a):
 106         return cls(**share1a)
 107
 108     @classmethod
 109     def from_share1b(cls, share1b):
 110         return cls(**share1b)
 111
 112     __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(' ')
 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) > 100:
 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         # XXX eww
 161         self.time_seen = time.time()
 162         self.shared = False
 163         self.peer = None
 164
 165     def as_block(self, tracker, net):
 166         if self.other_txs is None:
 167             raise ValueError('share does not contain all txs')
 168
 169         gentx = share_info_to_gentx(self.share_info, self.header['target'], tracker, net)
 170
 171         return dict(header=self.header, txs=[gentx] + self.other_txs)
 172
 173     def as_share1a(self):
 174         return dict(header=self.header, share_info=self.share_info, merkle_branch=self.merkle_branch)
 175
 176     def as_share1b(self):
 177         return dict(header=self.header, share_info=self.share_info, other_txs=self.other_txs)
 178
 179     def check(self, tracker, now, net):
 180         import time
 181         if self.previous_share_hash is not None:
 182             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):
 183                 raise ValueError('share from too far in the past!')
 184
 185         if self.header['timestamp'] > now + 2*60*60:
 186             raise ValueError('share from too far in the future!')
 187
 188         gentx = share_info_to_gentx(self.share_info, self.header['target'], tracker, net)
 189
 190         if check_merkle_branch(gentx, self.merkle_branch) != self.header['merkle_root']:
 191             raise ValueError('''gentx doesn't match header via merkle_branch''')
 192
 193         if self.other_txs is not None:
 194             if bitcoin_data.merkle_hash([gentx] + self.other_txs) != self.header['merkle_root']:
 195                 raise ValueError('''gentx doesn't match header via other_txs''')
 196
 197             if len(bitcoin_data.block_type.pack(dict(header=self.header, txs=[gentx] + self.other_txs))) > 1000000 - 1000:
 198                 raise ValueError('''block size too large''')
 199
 200     def flag_shared(self):
 201         self.shared = True
 202
 203     def __repr__(self):
 204         return '<Share %s>' % (' '.join('%s=%r' % (k, v) for k, v in self.__dict__.iteritems()),)
 205
 206 def get_pool_attempts_per_second(tracker, previous_share_hash, net, dist=None):
 207     if dist is None:
 208         dist = net.TARGET_LOOKBEHIND
 209     # XXX could be optimized to use nth_parent and cumulative_weights
 210     chain = list(itertools.islice(tracker.get_chain_to_root(previous_share_hash), dist))
 211     attempts = sum(bitcoin_data.target_to_average_attempts(share.target) for share in chain[:-1])
 212     time = chain[0].timestamp - chain[-1].timestamp
 213     if time == 0:
 214         time = 1
 215     return attempts//time
 216
 217 def generate_transaction(tracker, previous_share_hash, new_script, subsidy, nonce, block_target, net):
 218     height, last = tracker.get_height_and_last(previous_share_hash)
 219     if height < net.TARGET_LOOKBEHIND:
 220         target = bitcoin_data.FloatingIntegerType().truncate_to(2**256//2**20 - 1)
 221     else:
 222         attempts_per_second = get_pool_attempts_per_second(tracker, previous_share_hash, net)
 223         pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1
 224         previous_share = tracker.shares[previous_share_hash] if previous_share_hash is not None else None
 225         pre_target2 = math.clip(pre_target, (previous_share.target*9//10, previous_share.target*11//10))
 226         pre_target3 = math.clip(pre_target2, (0, net.MAX_TARGET))
 227         target = bitcoin_data.FloatingIntegerType().truncate_to(pre_target3)
 228
 229     attempts_to_block = bitcoin_data.target_to_average_attempts(block_target)
 230     max_weight = net.SPREAD * attempts_to_block
 231
 232     '''
 233     class fake_share(object):
 234         pass
 235     fake_share.new_script = new_script
 236     fake_share.target = target
 237
 238     dest_weights = {}
 239     total_weight = 0
 240     for share in itertools.chain([fake_share], itertools.islice(tracker.get_chain_to_root(previous_share_hash), net.CHAIN_LENGTH)):
 241         weight = bitcoin_data.target_to_average_attempts(share.target)
 242         if weight > max_weight - total_weight:
 243             weight = max_weight - total_weight
 244
 245         dest_weights[share.new_script] = dest_weights.get(share.new_script, 0) + weight
 246         total_weight += weight
 247
 248         if total_weight == max_weight:
 249             break
 250     '''
 251
 252     this_weight = min(bitcoin_data.target_to_average_attempts(target), max_weight)
 253     other_weights, other_weights_total = tracker.get_cumulative_weights(previous_share_hash, min(height, net.CHAIN_LENGTH), max(0, max_weight - this_weight))
 254     dest_weights, total_weight = math.add_dicts([{new_script: this_weight}, other_weights]), this_weight + other_weights_total
 255     total_weight = sum(dest_weights.itervalues())
 256
 257     amounts = dict((script, subsidy*(396*weight)//(400*total_weight)) for (script, weight) in dest_weights.iteritems())
 258     amounts[new_script] = amounts.get(new_script, 0) + subsidy*2//400
 259     amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy*2//400
 260     amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy - sum(amounts.itervalues()) # collect any extra
 261     if sum(amounts.itervalues()) != subsidy:
 262         raise ValueError()
 263     if any(x < 0 for x in amounts.itervalues()):
 264         raise ValueError()
 265
 266     pre_dests = sorted(amounts.iterkeys(), key=lambda script: (amounts[script], script))
 267     pre_dests = pre_dests[-4000:] # block length limit, unlikely to ever be hit
 268
 269     dests = sorted(pre_dests, key=lambda script: (script == new_script, script))
 270     assert dests[-1] == new_script
 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             log.err(None, 'Share check failed:')
 310             return False
 311         else:
 312             self.verified.add(share)
 313             return True
 314
 315     @defer.inlineCallbacks
 316     def think(self, ht, previous_block, now):
 317         desired = set()
 318
 319         # O(len(self.heads))
 320         #   make 'unverified heads' set?
 321         # for each overall head, attempt verification
 322         # if it fails, attempt on parent, and repeat
 323         # if no successful verification because of lack of parents, request parent
 324         bads = set()
 325         for head in set(self.heads) - set(self.verified.heads):
 326             head_height, last = self.get_height_and_last(head)
 327
 328             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))):
 329                 if self.attempt_verify(share, now):
 330                     break
 331                 if share.hash in self.heads:
 332                     bads.add(share.hash)
 333             else:
 334                 if last is not None:
 335                     desired.add((self.shares[random.choice(list(self.reverse_shares[last]))].peer, last))
 336         for bad in bads:
 337             assert bad not in self.verified.shares
 338             assert bad in self.heads
 339             self.remove(bad)
 340
 341         # try to get at least CHAIN_LENGTH height for each verified head, requesting parents if needed
 342         for head in list(self.verified.heads):
 343             head_height, last_hash = self.verified.get_height_and_last(head)
 344             last_height, last_last_hash = self.get_height_and_last(last_hash)
 345             # XXX review boundary conditions
 346             want = max(self.net.CHAIN_LENGTH - head_height, 0)
 347             can = max(last_height - 1 - self.net.CHAIN_LENGTH, 0) if last_last_hash is not None else last_height
 348             get = min(want, can)
 349             #print 'Z', head_height, last_hash is None, last_height, last_last_hash is None, want, can, get
 350             for share in itertools.islice(self.get_chain_known(last_hash), get):
 351                 if not self.attempt_verify(share, now):
 352                     break
 353                 if random.random() < .001:
 354                     #print 'YIELDING'
 355                     yield deferral.sleep(.01)
 356             if head_height < self.net.CHAIN_LENGTH and last_last_hash is not None:
 357                 desired.add((self.verified.shares[random.choice(list(self.verified.reverse_shares[last_hash]))].peer, last_last_hash))
 358
 359         # decide best tree
 360         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
 361         # decide best verified head
 362         scores = sorted(self.verified.tails.get(best_tail, []), key=lambda h: (
 363             self.verified.get_work(self.verified.get_nth_parent_hash(h, min(5, self.verified.get_height(h)))),
 364             ht.get_min_height(self.verified.shares[h].previous_block),
 365             self.verified.shares[h].peer is None,
 366             -self.verified.shares[h].time_seen
 367         ))
 368
 369
 370         if p2pool.DEBUG:
 371             print len(self.verified.tails.get(best_tail, []))
 372             for h in scores:
 373                 print '   ', format_hash(h), format_hash(self.verified.shares[h].previous_hash), (
 374                     self.verified.get_work(self.verified.get_nth_parent_hash(h, min(5, self.verified.get_height(h)))),
 375                     ht.get_min_height(self.verified.shares[h].previous_block),
 376                     self.verified.shares[h].peer is None,
 377                     -self.verified.shares[h].time_seen
 378                 )
 379
 380         for share_hash in scores[:-5]:
 381             if self.shares[share_hash].time_seen > time.time() - 30:
 382                 continue
 383             self.remove(share_hash)
 384             self.verified.remove(share_hash)
 385
 386         #for tail, heads in list(self.tails.iteritems()):
 387         #    if min(self.get_height(head) for head in heads) > 2*net.CHAIN_LENGTH + 10:
 388         #        self.remove(tail)
 389         #        self.verified.remove(tail)
 390
 391         best = scores[-1] if scores else None
 392
 393         if best is not None:
 394             best_share = self.verified.shares[best]
 395             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:
 396                 if p2pool.DEBUG:
 397                     print 'Stale detected!'
 398                 best = best_share.previous_hash
 399
 400         defer.returnValue((best, desired))
 401
 402     @memoize.memoize_with_backing(expiring_dict.ExpiringDict(5, get_touches=False))
 403     def score(self, share_hash, ht):
 404         head_height, last = self.verified.get_height_and_last(share_hash)
 405         score2 = 0
 406         attempts = 0
 407         max_height = 0
 408         # XXX should only look past a certain share, not at recent ones
 409         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
 410         # XXX this must go in the opposite direction for max_height to make sense
 411         for share in reversed(list(itertools.islice(self.verified.get_chain_known(share2_hash), self.net.CHAIN_LENGTH))):
 412             max_height = max(max_height, ht.get_min_height(share.header['previous_block']))
 413             attempts += bitcoin_data.target_to_average_attempts(share.target)
 414             this_score = attempts//(ht.get_highest_height() - max_height + 1)
 415             if this_score > score2:
 416                 score2 = this_score
 417         return min(head_height, self.net.CHAIN_LENGTH), score2
 418
 419 def format_hash(x):
 420     if x is None:
 421         return 'xxxxxxxx'
 422     return '%08x' % (x % 2**32)
 423
 424 class Mainnet(bitcoin_data.Mainnet):
 425     SHARE_PERIOD = 5 # seconds
 426     CHAIN_LENGTH = 24*60*60//5 # shares
 427     TARGET_LOOKBEHIND = 200 # shares
 428     SPREAD = 3 # blocks
 429     SCRIPT = '4104ffd03de44a6e11b9917f3a29f9443283d9871c9d743ef30d5eddcd37094b64d1b3d8090496b53256786bf5c82932ec23c3b74d9f05a6f95a8b5529352656664bac'.decode('hex')
 430     IDENTIFIER = 'fc70035c7a81bc6f'.decode('hex')
 431     PREFIX = '2472ef181efcd37b'.decode('hex')
 432     ADDRS_TABLE = 'addrs'
 433     P2P_PORT = 9333
 434     MAX_TARGET = 2**256//2**32 - 1
 435     PERSIST = True
 436
 437 class Testnet(bitcoin_data.Testnet):
 438     SHARE_PERIOD = 1 # seconds
 439     CHAIN_LENGTH = 24*60*60//5 # shares
 440     TARGET_LOOKBEHIND = 200 # shares
 441     SPREAD = 3 # blocks
 442     SCRIPT = '410403ad3dee8ab3d8a9ce5dd2abfbe7364ccd9413df1d279bf1a207849310465b0956e5904b1155ecd17574778f9949589ebfd4fb33ce837c241474a225cf08d85dac'.decode('hex')
 443     IDENTIFIER = '5fc2be2d4f0d6bfb'.decode('hex')
 444     PREFIX = '3f6057a15036f441'.decode('hex')
 445     ADDRS_TABLE = 'addrs_testnet'
 446     P2P_PORT = 19333
 447     MAX_TARGET = 2**256//2**20 - 1
 448     PERSIST = False