p2pool/data.py

   1 from __future__ import division
   2
   3 import itertools
   4 import random
   5
   6 from twisted.python import log
   7
   8 from p2pool.util import math
   9 from p2pool.bitcoin import data as bitcoin_data
  10 from p2pool.util import memoize, expiring_dict
  11
  12 class CompressedList(bitcoin_data.Type):
  13     def __init__(self, inner):
  14         self.inner = inner
  15
  16     def read(self, file):
  17         values, file = bitcoin_data.ListType(self.inner).read(file)
  18         if values != sorted(set(values)):
  19             raise ValueError('invalid values')
  20         references, file = bitcoin_data.ListType(bitcoin_data.VarIntType()).read(file)
  21         return [values[reference] for reference in references], file
  22
  23     def write(self, file, item):
  24         values = sorted(set(item))
  25         values_map = dict((value, i) for i, value in enumerate(values))
  26         file = bitcoin_data.ListType(self.inner).write(file, values)
  27         return bitcoin_data.ListType(bitcoin_data.VarIntType()).write(file, [values_map[subitem] for subitem in item])
  28
  29
  30 merkle_branch_type = bitcoin_data.ListType(bitcoin_data.ComposedType([
  31     ('side', bitcoin_data.StructType('<B')), # enum?
  32     ('hash', bitcoin_data.HashType()),
  33 ]))
  34
  35
  36 share_data_type = bitcoin_data.ComposedType([
  37     ('previous_share_hash', bitcoin_data.PossiblyNone(0, bitcoin_data.HashType())),
  38     ('target2', bitcoin_data.FloatingIntegerType()),
  39     ('nonce', bitcoin_data.VarStrType()),
  40 ])
  41
  42
  43 coinbase_type = bitcoin_data.ComposedType([
  44     ('identifier', bitcoin_data.FixedStrType(8)),
  45     ('share_data', share_data_type),
  46 ])
  47
  48 share_info_type = bitcoin_data.ComposedType([
  49     ('share_data', share_data_type),
  50     ('new_script', bitcoin_data.VarStrType()),
  51     ('subsidy', bitcoin_data.StructType('<Q')),
  52 ])
  53
  54
  55 share1a_type = bitcoin_data.ComposedType([
  56     ('header', bitcoin_data.block_header_type),
  57     ('share_info', share_info_type),
  58     ('merkle_branch', merkle_branch_type),
  59 ])
  60
  61 share1b_type = bitcoin_data.ComposedType([
  62     ('header', bitcoin_data.block_header_type),
  63     ('share_info', share_info_type),
  64     ('other_txs', bitcoin_data.ListType(bitcoin_data.tx_type)),
  65 ])
  66
  67 shares_type = CompressedList(bitcoin_data.VarStrType())
  68
  69 def calculate_merkle_branch(txs, index):
  70     hash_list = [(bitcoin_data.tx_type.hash256(tx), i == index, []) for i, tx in enumerate(txs)]
  71
  72     while len(hash_list) > 1:
  73         hash_list = [
  74             (
  75                 bitcoin_data.merkle_record_type.hash256(dict(left=left, right=right)),
  76                 left_f or right_f,
  77                 (left_l if left_f else right_l) + [dict(side=1, hash=right) if left_f else dict(side=0, hash=left)],
  78             )
  79             for (left, left_f, left_l), (right, right_f, right_l) in
  80                 zip(hash_list[::2], hash_list[1::2] + [hash_list[::2][-1]])
  81         ]
  82
  83     assert hash_list[0][1]
  84     assert check_merkle_branch(txs[index], hash_list[0][2]) == hash_list[0][0]
  85
  86     return hash_list[0][2]
  87
  88 def check_merkle_branch(tx, branch):
  89     hash_ = bitcoin_data.tx_type.hash256(tx)
  90     for step in branch:
  91         if not step['side']:
  92             hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=step['hash'], right=hash_))
  93         else:
  94             hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=hash_, right=step['hash']))
  95     return hash_
  96
  97 def gentx_to_share_info(gentx):
  98     return dict(
  99         share_data=coinbase_type.unpack(gentx['tx_ins'][0]['script'])['share_data'],
 100         subsidy=sum(tx_out['value'] for tx_out in gentx['tx_outs']),
 101         new_script=gentx['tx_outs'][-1]['script'],
 102     )
 103
 104 def share_info_to_gentx(share_info, block_target, tracker, net):
 105     return generate_transaction(
 106         tracker=tracker,
 107         previous_share_hash=share_info['share_data']['previous_share_hash'],
 108         new_script=share_info['new_script'],
 109         subsidy=share_info['subsidy'],
 110         nonce=share_info['share_data']['nonce'],
 111         block_target=block_target,
 112         net=net,
 113     )
 114
 115 class Share(object):
 116     peer = None
 117     gentx = None
 118
 119     @classmethod
 120     def from_block(cls, block):
 121         return cls(block['header'], gentx_to_share_info(block['txs'][0]), other_txs=block['txs'][1:])
 122
 123     @classmethod
 124     def from_share1a(cls, share1a):
 125         return cls(**share1a)
 126
 127     @classmethod
 128     def from_share1b(cls, share1b):
 129         return cls(**share1b)
 130
 131     def __init__(self, header, share_info, merkle_branch=None, other_txs=None):
 132         if merkle_branch is None and other_txs is None:
 133             raise ValueError('need either merkle_branch or other_txs')
 134         if other_txs is not None:
 135             new_merkle_branch = calculate_merkle_branch([dict(version=0, tx_ins=[], tx_outs=[], lock_time=0)] + other_txs, 0)
 136             if merkle_branch is not None:
 137                 if merke_branch != new_merkle_branch:
 138                     raise ValueError('invalid merkle_branch and other_txs')
 139             merkle_branch = new_merkle_branch
 140
 141         if len(merkle_branch) > 16:
 142             raise ValueError('merkle_branch too long!')
 143
 144         self.header = header
 145         self.share_info = share_info
 146         self.merkle_branch = merkle_branch
 147         self.other_txs = other_txs
 148
 149         self.timestamp = self.header['timestamp']
 150
 151         self.share_data = self.share_info['share_data']
 152         self.new_script = self.share_info['new_script']
 153         self.subsidy = self.share_info['subsidy']
 154
 155         if len(self.new_script) > 100:
 156             raise ValueError('new_script too long!')
 157
 158         self.previous_hash = self.previous_share_hash = self.share_data['previous_share_hash']
 159         self.target2 = self.share_data['target2']
 160         self.nonce = self.share_data['nonce']
 161
 162         if len(self.nonce) > 20:
 163             raise ValueError('nonce too long!')
 164
 165         self.hash = bitcoin_data.block_header_type.hash256(header)
 166
 167         if self.hash > self.target2:
 168             print 'hash', hex(self.hash)
 169             print 'targ', hex(self.target2)
 170             raise ValueError('not enough work!')
 171
 172
 173         self.shared = False
 174
 175     def as_block(self):
 176         if self.other_txs is None:
 177             raise ValueError('share does not contain all txs')
 178
 179         return dict(header=self.header, txs=[self.gentx] + self.other_txs)
 180
 181     def as_share1a(self):
 182         return dict(header=self.header, share_info=self.share_info, merkle_branch=self.merkle_branch)
 183
 184     def as_share1b(self):
 185         return dict(header=self.header, share_info=self.share_info, other_txs=self.other_txs)
 186
 187     def check(self, tracker, net):
 188         import time
 189         if self.previous_share_hash is not None:
 190             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):
 191                 raise ValueError('share from too far in the past!')
 192
 193         # XXX use adjusted time
 194         if self.header['timestamp'] > time.time() + 2*60*60:
 195             raise ValueError('share from too far in the future!')
 196
 197         gentx = share_info_to_gentx(self.share_info, self.header['target'], tracker, net)
 198
 199         if check_merkle_branch(gentx, self.merkle_branch) != self.header['merkle_root']:
 200             raise ValueError('''gentx doesn't match header via merkle_branch''')
 201
 202         if self.other_txs is not None:
 203             if bitcoin_data.merkle_hash([gentx] + self.other_txs) != self.header['merkle_root']:
 204                 raise ValueError('''gentx doesn't match header via other_txs''')
 205
 206         self.gentx = gentx
 207
 208         return Share2(self)
 209
 210     def flag_shared(self):
 211         self.shared = True
 212
 213     def __repr__(self):
 214         return '<Share %s>' % (' '.join('%s=%r' % (k, v) for k, v in self.__dict__.iteritems()),)
 215
 216 class Share2(object):
 217     '''Share with associated data'''
 218
 219     def __init__(self, share):
 220         self.share = share
 221
 222         self.shared = False
 223
 224     def flag_shared(self):
 225         self.shared = True
 226
 227 def generate_transaction(tracker, previous_share_hash, new_script, subsidy, nonce, block_target, net):
 228     previous_share2 = tracker.shares[previous_share_hash] if previous_share_hash is not None else None
 229
 230     chain = list(itertools.islice(tracker.get_chain_to_root(previous_share_hash), net.TARGET_LOOKBEHIND))
 231     if len(chain) < net.TARGET_LOOKBEHIND:
 232         target2 = bitcoin_data.FloatingIntegerType().truncate_to(2**256//2**20 - 1)
 233     else:
 234         attempts = sum(bitcoin_data.target_to_average_attempts(share.target2) for share in chain[:-1])
 235         time = chain[0].timestamp - chain[-1].timestamp
 236         if time == 0:
 237             time = 1
 238         attempts_per_second = attempts//time
 239         pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1
 240         pre_target2 = math.clip(pre_target, (previous_share2.target2*9//10, previous_share2.target2*11//10))
 241         pre_target3 = math.clip(pre_target2, (0, 2**256//2**20 - 1))
 242         target2 = bitcoin_data.FloatingIntegerType().truncate_to(pre_target3)
 243         print attempts_per_second//1000, 'KHASH'
 244         #print 'TARGET', 2**256//target2, 2**256/pre_target
 245         #print 'ATT', bitcoin_data.target_to_average_attempts(target2)//1000
 246
 247
 248     attempts_to_block = bitcoin_data.target_to_average_attempts(block_target)
 249     max_weight = net.SPREAD * attempts_to_block
 250     total_weight = 0
 251
 252     class fake_share(object):
 253         pass
 254     fake_share.new_script = new_script
 255     fake_share.target2 = target2
 256
 257     dest_weights = {}
 258     for i, share in enumerate(itertools.chain([fake_share], itertools.islice(tracker.get_chain_to_root(previous_share_hash), net.CHAIN_LENGTH))):
 259         weight = bitcoin_data.target_to_average_attempts(share.target2)
 260         if weight > max_weight - total_weight:
 261             weight = max_weight - total_weight
 262
 263         dest_weights[share.new_script] = dest_weights.get(share.new_script, 0) + weight
 264         total_weight += weight
 265
 266         if total_weight == max_weight:
 267             break
 268
 269     amounts = dict((script, subsidy*(199*weight)//(200*total_weight)) for (script, weight) in dest_weights.iteritems())
 270     amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy*1//200
 271     amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy - sum(amounts.itervalues()) # collect any extra
 272
 273     dests = sorted(amounts.iterkeys(), key=lambda script: (script == new_script, script))
 274     assert dests[-1] == new_script
 275
 276     return dict(
 277         version=1,
 278         tx_ins=[dict(
 279             previous_output=None,
 280             sequence=None,
 281             script=coinbase_type.pack(dict(
 282                 identifier=net.IDENTIFIER,
 283                 share_data=dict(
 284                     previous_share_hash=previous_share_hash,
 285                     nonce=nonce,
 286                     target2=target2,
 287                 ),
 288             )),
 289         )],
 290         tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script]],
 291         lock_time=0,
 292     )
 293
 294
 295
 296 class OkayTracker(bitcoin_data.Tracker):
 297     def __init__(self, net):
 298         bitcoin_data.Tracker.__init__(self)
 299         self.net = net
 300         self.verified = bitcoin_data.Tracker()
 301
 302         self.okay_cache = {} # hash -> height
 303
 304     def attempt_verify(self, share):
 305         height, last = self.get_height_and_last(share.hash)
 306         if height < self.net.CHAIN_LENGTH and last is not None:
 307             raise AssertionError()
 308         if share.hash in self.verified.shares:
 309             return True
 310         try:
 311             share.check(self, self.net)
 312         except:
 313             print
 314             print 'Share check failed:'
 315             log.err()
 316             print
 317             return False
 318         else:
 319             self.verified.add(share)
 320             return True
 321
 322     def think(self, ht):
 323         desired = set()
 324
 325         # O(len(self.heads))
 326         #   make 'unverified heads' set?
 327         # for each overall head, attempt verification
 328         # if it fails, attempt on parent, and repeat
 329         # if no successful verification because of lack of parents, request parent
 330         for head in self.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 max(0, head_height - self.net.CHAIN_LENGTH)):
 334                 if self.attempt_verify(share):
 335                     break
 336             else:
 337                 desired.add((self.shares[random.choice(list(self.reverse_shares[last]))].peer, last))
 338
 339         # try to get at least CHAIN_LENGTH height for each verified head, requesting parents if needed
 340         for head in list(self.verified.heads):
 341             head_height, last_hash = self.verified.get_height_and_last(head)
 342             last_height, last_last_hash = self.get_height_and_last(last_hash)
 343             # XXX review boundary conditions
 344             want = max(self.net.CHAIN_LENGTH - head_height, 0)
 345             can = max(last_height - 1 - self.net.CHAIN_LENGTH, 0) if last_last_hash is not None else last_height
 346             get = min(want, can)
 347             #print 'Z', head_height, last_hash is None, last_height, last_last_hash is None, want, can, get
 348             for share in itertools.islice(self.get_chain_known(last_hash), get):
 349                 if not self.attempt_verify(share):
 350                     break
 351             if head_height < self.net.CHAIN_LENGTH and last_last_hash is not None:
 352                 desired.add((self.verified.shares[random.choice(list(self.verified.reverse_shares[last_hash]))].peer, last_last_hash))
 353
 354         # decide best verified head
 355         best = max(self.verified.heads, key=lambda h: self.score(h, ht)) if self.verified.heads else None
 356
 357         return best, desired
 358
 359     @memoize.memoize_with_backing(expiring_dict.ExpiringDict(5, get_touches=False))
 360     def score(self, share_hash, ht):
 361         head_height, last = self.verified.get_height_and_last(share_hash)
 362         score2 = 0
 363         attempts = 0
 364         max_height = 0
 365         # XXX should only look past a certain share, not at recent ones
 366         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
 367         # XXX this must go in the opposite direction for max_height to make sense
 368         for share in reversed(list(itertools.islice(self.verified.get_chain_known(share2_hash), self.net.CHAIN_LENGTH))):
 369             max_height = max(max_height, ht.get_min_height(share.header['previous_block']))
 370             attempts += bitcoin_data.target_to_average_attempts(share.target2)
 371             this_score = attempts//(ht.get_highest_height() - max_height + 1)
 372             #this_score = -(ht.get_highest_height() - max_height + 1)//attempts
 373             if this_score > score2:
 374                 score2 = this_score
 375         res = (min(head_height, self.net.CHAIN_LENGTH), score2)
 376         print res
 377         return res
 378
 379
 380 class Mainnet(bitcoin_data.Mainnet):
 381     SHARE_PERIOD = 5 # seconds
 382     CHAIN_LENGTH = 24*60*60//5 # shares
 383     TARGET_LOOKBEHIND = 200 # shares
 384     SPREAD = 3 # blocks
 385     SCRIPT = '4104ffd03de44a6e11b9917f3a29f9443283d9871c9d743ef30d5eddcd37094b64d1b3d8090496b53256786bf5c82932ec23c3b74d9f05a6f95a8b5529352656664bac'.decode('hex')
 386     IDENTIFIER = '7452839666e1f8f8'.decode('hex')
 387     PREFIX = '2d4224bf18c87b87'.decode('hex')
 388     ADDRS_TABLE = 'addrs'
 389     P2P_PORT = 9333
 390
 391 class Testnet(bitcoin_data.Testnet):
 392     SHARE_PERIOD = 1 # seconds
 393     CHAIN_LENGTH = 24*60*60//5 # shares
 394     TARGET_LOOKBEHIND = 200 # shares
 395     SPREAD = 3 # blocks
 396     SCRIPT = '410403ad3dee8ab3d8a9ce5dd2abfbe7364ccd9413df1d279bf1a207849310465b0956e5904b1155ecd17574778f9949589ebfd4fb33ce837c241474a225cf08d85dac'.decode('hex')
 397     IDENTIFIER = '1ae3479e4eb6700a'.decode('hex')
 398     PREFIX = 'd19778c812754854'.decode('hex')
 399     ADDRS_TABLE = 'addrs_testnet'
 400     P2P_PORT = 19333