p2pool/data.py

   1 from __future__ import division
   2
   3 import itertools
   4 import random
   5 import time
   6 import os
   7
   8 from twisted.python import log
   9
  10 import p2pool
  11 from p2pool import skiplists
  12 from p2pool.bitcoin import data as bitcoin_data, script, networks
  13 from p2pool.util import memoize, expiring_dict, math
  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.PossiblyNoneType(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 new_share_data_type = bitcoin_data.ComposedType([
  54     ('previous_share_hash', bitcoin_data.PossiblyNoneType(0, bitcoin_data.HashType())),
  55     ('coinbase', bitcoin_data.VarStrType()),
  56     ('nonce', bitcoin_data.VarStrType()),
  57     ('new_script', bitcoin_data.VarStrType()),
  58     ('subsidy', bitcoin_data.StructType('<Q')),
  59     ('donation', bitcoin_data.StructType('<H')),
  60     ('timestamp', bitcoin_data.StructType('<I')),
  61     ('stale_frac', bitcoin_data.StructType('<B')),
  62 ])
  63
  64 new_share_info_type = bitcoin_data.ComposedType([
  65     ('new_share_data', new_share_data_type),
  66     ('target', bitcoin_data.FloatingIntegerType()),
  67 ])
  68
  69 new_share1a_type = bitcoin_data.ComposedType([
  70     ('header', bitcoin_data.block_header_type),
  71     ('share_info', new_share_info_type),
  72     ('merkle_branch', bitcoin_data.merkle_branch_type),
  73 ])
  74
  75 new_share1b_type = bitcoin_data.ComposedType([
  76     ('header', bitcoin_data.block_header_type),
  77     ('share_info', new_share_info_type),
  78     ('other_txs', bitcoin_data.ListType(bitcoin_data.tx_type)),
  79 ])
  80
  81 # type:
  82 # 0: new_share1a
  83 # 1: new_share1b
  84
  85 new_share_type = bitcoin_data.ComposedType([
  86     ('type', bitcoin_data.VarIntType()),
  87     ('contents', bitcoin_data.VarStrType()),
  88 ])
  89
  90 def calculate_merkle_branch(txs, index):
  91     hash_list = [(bitcoin_data.tx_type.hash256(tx), i == index, []) for i, tx in enumerate(txs)]
  92
  93     while len(hash_list) > 1:
  94         hash_list = [
  95             (
  96                 bitcoin_data.merkle_record_type.hash256(dict(left=left, right=right)),
  97                 left_f or right_f,
  98                 (left_l if left_f else right_l) + [dict(side=1, hash=right) if left_f else dict(side=0, hash=left)],
  99             )
 100             for (left, left_f, left_l), (right, right_f, right_l) in
 101                 zip(hash_list[::2], hash_list[1::2] + [hash_list[::2][-1]])
 102         ]
 103
 104     assert hash_list[0][1]
 105     assert check_merkle_branch(txs[index], hash_list[0][2]) == hash_list[0][0]
 106
 107     return hash_list[0][2]
 108
 109 def check_merkle_branch(tx, branch):
 110     hash_ = bitcoin_data.tx_type.hash256(tx)
 111     for step in branch:
 112         if not step['side']:
 113             hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=step['hash'], right=hash_))
 114         else:
 115             hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=hash_, right=step['hash']))
 116     return hash_
 117
 118 def share_info_to_gentx(share_info, block_target, tracker, net):
 119     return generate_transaction(
 120         tracker=tracker,
 121         previous_share_hash=share_info['share_data']['previous_share_hash'],
 122         new_script=share_info['new_script'],
 123         subsidy=share_info['subsidy'],
 124         nonce=share_info['share_data']['nonce'],
 125         block_target=block_target,
 126         net=net,
 127     )[1]
 128
 129 class Share(object):
 130     donation = 0
 131
 132     @classmethod
 133     def from_share1a(cls, share1a, net):
 134         return cls(net, **share1a)
 135
 136     @classmethod
 137     def from_share1b(cls, share1b, net):
 138         return cls(net, **share1b)
 139
 140     __slots__ = 'header previous_block share_info merkle_branch other_txs timestamp share_data new_script subsidy previous_hash previous_share_hash target nonce pow_hash header_hash hash time_seen shared stored peer'.split(' ')
 141
 142     def __init__(self, net, header, share_info, merkle_branch=None, other_txs=None):
 143         if merkle_branch is None and other_txs is None:
 144             raise ValueError('need either merkle_branch or other_txs')
 145         if other_txs is not None:
 146             new_merkle_branch = calculate_merkle_branch([dict(version=0, tx_ins=[], tx_outs=[], lock_time=0)] + other_txs, 0)
 147             if merkle_branch is not None:
 148                 if merke_branch != new_merkle_branch:
 149                     raise ValueError('invalid merkle_branch and other_txs')
 150             merkle_branch = new_merkle_branch
 151
 152         if len(merkle_branch) > 16:
 153             raise ValueError('merkle_branch too long!')
 154
 155         self.header = header
 156         self.previous_block = header['previous_block']
 157         self.share_info = share_info
 158         self.merkle_branch = merkle_branch
 159         self.other_txs = other_txs
 160
 161         self.timestamp = self.header['timestamp']
 162
 163         self.share_data = self.share_info['share_data']
 164         self.new_script = self.share_info['new_script']
 165         self.subsidy = self.share_info['subsidy']
 166
 167         if len(self.new_script) > 100:
 168             raise ValueError('new_script too long!')
 169
 170         self.previous_hash = self.previous_share_hash = self.share_data['previous_share_hash']
 171         self.target = self.share_data['target']
 172         self.nonce = self.share_data['nonce']
 173
 174         if len(self.nonce) > 100:
 175             raise ValueError('nonce too long!')
 176
 177         self.pow_hash = net.BITCOIN_POW_FUNC(header)
 178         self.header_hash = bitcoin_data.block_header_type.hash256(header)
 179
 180         if net.BITCOIN_POW_FUNC == bitcoin_data.block_header_type.scrypt:
 181             # compatibility hack
 182             self.hash = share1a_type.scrypt(self.as_share1a())
 183         else:
 184             self.hash = share1a_type.hash256(self.as_share1a())
 185
 186         if self.pow_hash > self.target:
 187             print 'hash %x' % self.pow_hash
 188             print 'targ %x' % self.target
 189             raise ValueError('not enough work!')
 190
 191         if script.get_sigop_count(self.new_script) > 1:
 192             raise ValueError('too many sigops!')
 193
 194         # XXX eww
 195         self.time_seen = time.time()
 196         self.shared = False
 197         self.stored = False
 198         self.peer = None
 199
 200     def as_block(self, tracker, net):
 201         if self.other_txs is None:
 202             raise ValueError('share does not contain all txs')
 203
 204         gentx = share_info_to_gentx(self.share_info, self.header['target'], tracker, net)
 205
 206         return dict(header=self.header, txs=[gentx] + self.other_txs)
 207
 208     def as_share1a(self):
 209         return dict(header=self.header, share_info=self.share_info, merkle_branch=self.merkle_branch)
 210
 211     def as_share1b(self):
 212         if self.other_txs is None:
 213             raise ValueError('share does not contain all txs')
 214
 215         return dict(header=self.header, share_info=self.share_info, other_txs=self.other_txs)
 216
 217     def check(self, tracker, now, net):
 218         import time
 219         if self.previous_share_hash is not None:
 220             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):
 221                 raise ValueError('share from too far in the past!')
 222
 223         if self.header['timestamp'] > now + 2*60*60:
 224             raise ValueError('share from too far in the future!')
 225
 226         gentx = share_info_to_gentx(self.share_info, self.header['target'], tracker, net)
 227
 228         if len(gentx['tx_ins'][0]['script']) > 100:
 229             raise ValueError('coinbase too large! %i bytes' % (len(gentx['tx_ins'][0]['script']),))
 230
 231         if check_merkle_branch(gentx, self.merkle_branch) != self.header['merkle_root']:
 232             raise ValueError('''gentx doesn't match header via merkle_branch''')
 233
 234         if self.other_txs is not None:
 235             if bitcoin_data.merkle_hash([gentx] + self.other_txs) != self.header['merkle_root']:
 236                 raise ValueError('''gentx doesn't match header via other_txs''')
 237
 238             if len(bitcoin_data.block_type.pack(dict(header=self.header, txs=[gentx] + self.other_txs))) > 1000000 - 1000:
 239                 raise ValueError('block size too large')
 240
 241     def flag_shared(self):
 242         self.shared = True
 243
 244     def __repr__(self):
 245         return '<Share %s>' % (' '.join('%s=%r' % (k, getattr(self, k)) for k in self.__slots__),)
 246
 247 class NewShare(Share):
 248     @classmethod
 249     def from_share(cls, share, net):
 250         if share['type'] == 0:
 251             res = cls.from_share1a(new_share1a_type.unpack(share['contents']), net)
 252             if not (res.pow_hash > res.header['target']):
 253                 raise ValueError('invalid share type')
 254             return res
 255         elif share['type'] == 1:
 256             res = cls.from_share1b(new_share1b_type.unpack(share['contents']), net)
 257             if not (res.pow_hash <= res.header['target']):
 258                 raise ValueError('invalid share type')
 259             return res
 260         else:
 261             raise ValueError('unknown share type: %r' % (share['type'],))
 262
 263     def as_share(self):
 264         if self.pow_hash > self.header['target']: # new_share1a
 265             return dict(type=0, contents=new_share1a_type.pack(self.as_share1a()))
 266         elif self.pow_hash <= self.header['target']: # new_share1b
 267             return dict(type=1, contents=new_share1b_type.pack(self.as_share1b()))
 268         else:
 269             raise AssertionError()
 270
 271     def __init__(self, net, header, new_share_info, merkle_branch=None, other_txs=None):
 272         if merkle_branch is None and other_txs is None:
 273             raise ValueError('need either merkle_branch or other_txs')
 274         if other_txs is not None:
 275             new_merkle_branch = bitcoin_data.calculate_merkle_branch([dict(version=0, tx_ins=[], tx_outs=[], lock_time=0)] + other_txs, 0)
 276             if merkle_branch is not None:
 277                 if merke_branch != new_merkle_branch:
 278                     raise ValueError('invalid merkle_branch and other_txs')
 279             merkle_branch = new_merkle_branch
 280
 281         if len(merkle_branch) > 16:
 282             raise ValueError('merkle_branch too long!')
 283
 284         self.header = header
 285         self.previous_block = header['previous_block']
 286         self.share_info = new_share_info
 287         self.merkle_branch = merkle_branch
 288         self.other_txs = other_txs
 289
 290         self.share_data = self.share_info['new_share_data']
 291         self.target = self.share_info['target']
 292
 293         self.new_script = self.share_data['new_script']
 294         self.subsidy = self.share_data['subsidy']
 295         self.timestamp = self.share_data['timestamp']
 296
 297         if len(self.new_script) > 100:
 298             raise ValueError('new_script too long!')
 299
 300         self.previous_hash = self.previous_share_hash = self.share_data['previous_share_hash']
 301         self.nonce = self.share_data['nonce']
 302
 303         if len(self.nonce) > 100:
 304             raise ValueError('nonce too long!')
 305
 306         if len(self.share_data['coinbase']) > 100:
 307             raise ValueError('''coinbase too large! %i bytes''' % (len(self.share_data['coinbase']),))
 308
 309         self.pow_hash = net.BITCOIN_POW_FUNC(header)
 310         self.header_hash = bitcoin_data.block_header_type.hash256(header)
 311
 312         self.hash = new_share1a_type.hash256(self.as_share1a())
 313
 314         if self.pow_hash > self.target:
 315             print 'hash %x' % self.pow_hash
 316             print 'targ %x' % self.target
 317             raise ValueError('not enough work!')
 318
 319         if script.get_sigop_count(self.new_script) > 1:
 320             raise ValueError('too many sigops!')
 321
 322         # XXX eww
 323         self.time_seen = time.time()
 324         self.shared = False
 325         self.stored = False
 326         self.peer = None
 327
 328     def check(self, tracker, now, net):
 329         if self.previous_share_hash is not None:
 330             previous_share = tracker.shares[self.previous_share_hash]
 331             if not (previous_share.timestamp - 60 <= self.timestamp <= previous_share.timestamp + 60):
 332                 raise ValueError('share timestamp (%i) too far from previous timestamp (%i)' % (self.timestamp, previous_share.timestamp))
 333
 334         new_share_info, gentx = new_generate_transaction(tracker, self.share_info['new_share_data'], self.header['target'], net)
 335         if new_share_info != self.share_info:
 336             raise ValueError('share difficulty invalid')
 337
 338         if bitcoin_data.check_merkle_branch(gentx, 0, self.merkle_branch) != self.header['merkle_root']:
 339             raise ValueError('''gentx doesn't match header via merkle_branch''')
 340
 341         if self.other_txs is not None:
 342             if bitcoin_data.merkle_hash([gentx] + self.other_txs) != self.header['merkle_root']:
 343                 raise ValueError('''gentx doesn't match header via other_txs''')
 344
 345             if len(bitcoin_data.block_type.pack(dict(header=self.header, txs=[gentx] + self.other_txs))) > 1000000 - 1000:
 346                 raise ValueError('block size too large')
 347
 348 def get_pool_attempts_per_second(tracker, previous_share_hash, net, dist=None):
 349     if dist is None:
 350         dist = net.TARGET_LOOKBEHIND
 351     near = tracker.shares[previous_share_hash]
 352     far = tracker.shares[tracker.get_nth_parent_hash(previous_share_hash, dist - 1)]
 353     attempts = tracker.get_work(near.hash) - tracker.get_work(far.hash)
 354     time = near.timestamp - far.timestamp
 355     if time == 0:
 356         time = 1
 357     return attempts//time
 358
 359 def generate_transaction(tracker, previous_share_hash, new_script, subsidy, nonce, block_target, net):
 360     height, last = tracker.get_height_and_last(previous_share_hash)
 361     assert height >= net.CHAIN_LENGTH or last is None
 362     if height < net.TARGET_LOOKBEHIND:
 363         target = bitcoin_data.FloatingInteger.from_target_upper_bound(net.MAX_TARGET)
 364     else:
 365         attempts_per_second = get_pool_attempts_per_second(tracker, previous_share_hash, net)
 366         previous_share = tracker.shares[previous_share_hash] if previous_share_hash is not None else None
 367         pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1
 368         pre_target2 = math.clip(pre_target, (previous_share.target*9//10, previous_share.target*11//10))
 369         pre_target3 = math.clip(pre_target2, (0, net.MAX_TARGET))
 370         target = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
 371
 372     attempts_to_block = bitcoin_data.target_to_average_attempts(block_target)
 373     max_weight = 65535 * net.SPREAD * attempts_to_block
 374
 375     this_weight = 65535 * min(bitcoin_data.target_to_average_attempts(target), max_weight)
 376     other_weights, other_weights_total, other_donation_weight_total = tracker.get_cumulative_weights(previous_share_hash, min(height, net.CHAIN_LENGTH), max(0, max_weight - this_weight))
 377     dest_weights, total_weight, donation_weight_total = math.add_dicts([{new_script: this_weight}, other_weights]), this_weight + other_weights_total, other_donation_weight_total
 378     assert total_weight == sum(dest_weights.itervalues()) + donation_weight_total
 379
 380     if net.SCRIPT:
 381         amounts = dict((script, subsidy*(396*weight)//(400*total_weight)) for (script, weight) in dest_weights.iteritems())
 382         amounts[new_script] = amounts.get(new_script, 0) + subsidy*2//400
 383         amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy*2//400
 384         amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy - sum(amounts.itervalues()) # collect any extra
 385     else:
 386         amounts = dict((script, subsidy*(398*weight)//(400*total_weight)) for (script, weight) in dest_weights.iteritems())
 387         amounts[new_script] = amounts.get(new_script, 0) + subsidy*2//400
 388         amounts[new_script] = amounts.get(new_script, 0) + subsidy - sum(amounts.itervalues()) # collect any extra
 389
 390     if sum(amounts.itervalues()) != subsidy:
 391         raise ValueError()
 392     if any(x < 0 for x in amounts.itervalues()):
 393         raise ValueError()
 394
 395     pre_dests = sorted(amounts.iterkeys(), key=lambda script: (amounts[script], script))
 396     pre_dests = pre_dests[-4000:] # block length limit, unlikely to ever be hit
 397
 398     dests = sorted(pre_dests, key=lambda script: (script == new_script, script))
 399     assert dests[-1] == new_script
 400
 401     share_data = dict(
 402         previous_share_hash=previous_share_hash,
 403         nonce=nonce,
 404         target=target,
 405     )
 406
 407     share_info = dict(
 408         share_data=share_data,
 409         new_script=new_script,
 410         subsidy=subsidy,
 411     )
 412
 413     return share_info, dict(
 414         version=1,
 415         tx_ins=[dict(
 416             previous_output=None,
 417             sequence=None,
 418             script=coinbase_type.pack(dict(
 419                 identifier=net.IDENTIFIER,
 420                 share_data=share_data,
 421             )),
 422         )],
 423         tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script]],
 424         lock_time=0,
 425     )
 426
 427 def new_generate_transaction(tracker, new_share_data, block_target, net):
 428     previous_share_hash = new_share_data['previous_share_hash']
 429     new_script = new_share_data['new_script']
 430     subsidy = new_share_data['subsidy']
 431     donation = new_share_data['donation']
 432     assert 0 <= donation <= 65535
 433
 434     height, last = tracker.get_height_and_last(previous_share_hash)
 435     assert height >= net.CHAIN_LENGTH or last is None
 436     if height < net.TARGET_LOOKBEHIND:
 437         target = bitcoin_data.FloatingInteger.from_target_upper_bound(net.MAX_TARGET)
 438     else:
 439         attempts_per_second = get_pool_attempts_per_second(tracker, previous_share_hash, net)
 440         previous_share = tracker.shares[previous_share_hash] if previous_share_hash is not None else None
 441         pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1
 442         pre_target2 = math.clip(pre_target, (previous_share.target*9//10, previous_share.target*11//10))
 443         pre_target3 = math.clip(pre_target2, (0, net.MAX_TARGET))
 444         target = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
 445
 446     attempts_to_block = bitcoin_data.target_to_average_attempts(block_target)
 447     max_att = net.SPREAD * attempts_to_block
 448
 449     this_att = min(bitcoin_data.target_to_average_attempts(target), max_att)
 450     other_weights, other_total_weight, other_donation_weight = tracker.get_cumulative_weights(previous_share_hash, min(height, net.CHAIN_LENGTH), 65535*max(0, max_att - this_att))
 451     assert other_total_weight == sum(other_weights.itervalues()) + other_donation_weight, (other_total_weight, sum(other_weights.itervalues()) + other_donation_weight)
 452     weights, total_weight, donation_weight = math.add_dicts([{new_script: this_att*(65535-donation)}, other_weights]), this_att*65535 + other_total_weight, this_att*donation + other_donation_weight
 453     assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
 454
 455     amounts = dict((script, subsidy*(199*weight)//(200*total_weight)) for (script, weight) in weights.iteritems())
 456     amounts[new_script] = amounts.get(new_script, 0) + subsidy//200
 457     amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy*(199*donation_weight)//(200*total_weight)
 458     amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy - sum(amounts.itervalues()) # collect any extra satoshis :P
 459
 460     if sum(amounts.itervalues()) != subsidy:
 461         raise ValueError()
 462     if any(x < 0 for x in amounts.itervalues()):
 463         print amounts
 464         import code
 465         d = globals()
 466         d.update(locals())
 467         code.interact(local=d)
 468         raise ValueError()
 469
 470     pre_dests = sorted(amounts.iterkeys(), key=lambda script: (amounts[script], script))
 471     pre_dests = pre_dests[-4000:] # block length limit, unlikely to ever be hit
 472
 473     dests = sorted(pre_dests, key=lambda script: (script == new_script, script))
 474     assert dests[-1] == new_script
 475
 476     new_share_info = dict(
 477         new_share_data=new_share_data,
 478         target=target,
 479     )
 480
 481     return new_share_info, dict(
 482         version=1,
 483         tx_ins=[dict(
 484             previous_output=None,
 485             sequence=None,
 486             script=new_share_data['coinbase'],
 487         )],
 488         tx_outs=[dict(value=0, script=bitcoin_data.HashType().pack(new_share_info_type.hash256(new_share_info)))] + [dict(value=amounts[script], script=script) for script in dests if amounts[script]],
 489         lock_time=0,
 490     )
 491
 492
 493 class OkayTracker(bitcoin_data.Tracker):
 494     def __init__(self, net):
 495         bitcoin_data.Tracker.__init__(self)
 496         self.net = net
 497         self.verified = bitcoin_data.Tracker()
 498         self.verified.get_nth_parent_hash = self.get_nth_parent_hash # self is a superset of self.verified
 499
 500         self.get_cumulative_weights = skiplists.WeightsSkipList(self)
 501
 502     def add(self, share, known_verified=False):
 503         bitcoin_data.Tracker.add(self, share)
 504         if known_verified:
 505             self.verified.add(share)
 506
 507     def attempt_verify(self, share, now):
 508         if share.hash in self.verified.shares:
 509             return True
 510         height, last = self.get_height_and_last(share.hash)
 511         if height < self.net.CHAIN_LENGTH + 1 and last is not None:
 512             raise AssertionError()
 513         try:
 514             share.check(self, now, self.net)
 515         except:
 516             log.err(None, 'Share check failed:')
 517             return False
 518         else:
 519             self.verified.add(share)
 520             return True
 521
 522     def think(self, ht, previous_block, now):
 523         desired = set()
 524
 525         # O(len(self.heads))
 526         #   make 'unverified heads' set?
 527         # for each overall head, attempt verification
 528         # if it fails, attempt on parent, and repeat
 529         # if no successful verification because of lack of parents, request parent
 530         bads = set()
 531         for head in set(self.heads) - set(self.verified.heads):
 532             head_height, last = self.get_height_and_last(head)
 533
 534             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))):
 535                 if self.attempt_verify(share, now):
 536                     break
 537                 if share.hash in self.heads:
 538                     bads.add(share.hash)
 539             else:
 540                 if last is not None:
 541                     desired.add((self.shares[random.choice(list(self.reverse_shares[last]))].peer, last))
 542         for bad in bads:
 543             assert bad not in self.verified.shares
 544             assert bad in self.heads
 545             if p2pool.DEBUG:
 546                 print "BAD", bad
 547             self.remove(bad)
 548
 549         # try to get at least CHAIN_LENGTH height for each verified head, requesting parents if needed
 550         for head in list(self.verified.heads):
 551             head_height, last_hash = self.verified.get_height_and_last(head)
 552             last_height, last_last_hash = self.get_height_and_last(last_hash)
 553             # XXX review boundary conditions
 554             want = max(self.net.CHAIN_LENGTH - head_height, 0)
 555             can = max(last_height - 1 - self.net.CHAIN_LENGTH, 0) if last_last_hash is not None else last_height
 556             get = min(want, can)
 557             #print 'Z', head_height, last_hash is None, last_height, last_last_hash is None, want, can, get
 558             for share in itertools.islice(self.get_chain_known(last_hash), get):
 559                 if not self.attempt_verify(share, now):
 560                     break
 561             if head_height < self.net.CHAIN_LENGTH and last_last_hash is not None:
 562                 desired.add((self.verified.shares[random.choice(list(self.verified.reverse_shares[last_hash]))].peer, last_last_hash))
 563
 564         # decide best tree
 565         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
 566         # decide best verified head
 567         scores = sorted(self.verified.tails.get(best_tail, []), key=lambda h: (
 568             self.verified.get_work(self.verified.get_nth_parent_hash(h, min(5, self.verified.get_height(h)))),
 569             #self.verified.shares[h].peer is None,
 570             ht.get_min_height(self.verified.shares[h].previous_block),
 571             -self.verified.shares[h].time_seen
 572         ))
 573
 574
 575         if p2pool.DEBUG:
 576             print len(self.verified.tails), "chain tails and", len(self.verified.tails.get(best_tail, [])), 'chain heads. Top 10 tails:'
 577             if len(scores) > 10:
 578                 print '    ...'
 579             for h in scores[-10:]:
 580                 print '   ', format_hash(h), format_hash(self.verified.shares[h].previous_hash), (
 581                     self.verified.get_work(self.verified.get_nth_parent_hash(h, min(5, self.verified.get_height(h)))),
 582                     self.verified.shares[h].peer is None,
 583                     ht.get_min_height(self.verified.shares[h].previous_block),
 584                     -self.verified.shares[h].time_seen
 585                 )
 586
 587         # eat away at heads
 588         if scores:
 589             for i in xrange(1000):
 590                 to_remove = set()
 591                 for share_hash, tail in self.heads.iteritems():
 592                     if share_hash in scores[-5:]:
 593                         #print 1
 594                         continue
 595                     if self.shares[share_hash].time_seen > time.time() - 300:
 596                         #print 2
 597                         continue
 598                     if share_hash not in self.verified.shares and max(self.shares[after_tail_hash].time_seen for after_tail_hash in self.reverse_shares.get(tail)) > time.time() - 120: # XXX stupid
 599                         #print 3
 600                         continue
 601                     to_remove.add(share_hash)
 602                 if not to_remove:
 603                     break
 604                 for share_hash in to_remove:
 605                     self.remove(share_hash)
 606                     if share_hash in self.verified.shares:
 607                         self.verified.remove(share_hash)
 608                 #print "_________", to_remove
 609
 610         # drop tails
 611         for i in xrange(1000):
 612             to_remove = set()
 613             for tail, heads in self.tails.iteritems():
 614                 if min(self.get_height(head) for head in heads) < 2*self.net.CHAIN_LENGTH + 10:
 615                     continue
 616                 for aftertail in self.reverse_shares.get(tail, set()):
 617                     if len(self.reverse_shares[self.shares[aftertail].previous_hash]) > 1: # XXX
 618                         print "raw"
 619                         continue
 620                     to_remove.add(aftertail)
 621             if not to_remove:
 622                 break
 623             # if removed from this, it must be removed from verified
 624             #start = time.time()
 625             for aftertail in to_remove:
 626                 if self.shares[aftertail].previous_hash not in self.tails:
 627                     print "erk", aftertail, self.shares[aftertail].previous_hash
 628                     continue
 629                 self.remove(aftertail)
 630                 if aftertail in self.verified.shares:
 631                     self.verified.remove(aftertail)
 632             #end = time.time()
 633             #print "removed! %i %f" % (len(to_remove), (end - start)/len(to_remove))
 634
 635         best = scores[-1] if scores else None
 636
 637         if best is not None:
 638             best_share = self.verified.shares[best]
 639             if ht.get_min_height(best_share.header['previous_block']) < ht.get_min_height(previous_block) and best_share.header_hash != previous_block and best_share.peer is not None:
 640                 if p2pool.DEBUG:
 641                     print 'Stale detected! %x < %x' % (best_share.header['previous_block'], previous_block)
 642                 best = best_share.previous_hash
 643
 644         return best, desired
 645
 646     @memoize.memoize_with_backing(expiring_dict.ExpiringDict(5, get_touches=False))
 647     def score(self, share_hash, ht):
 648         head_height, last = self.verified.get_height_and_last(share_hash)
 649         score2 = 0
 650         attempts = 0
 651         max_height = 0
 652         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
 653         for share in reversed(list(itertools.islice(self.verified.get_chain_known(share2_hash), self.net.CHAIN_LENGTH))):
 654             max_height = max(max_height, ht.get_min_height(share.header['previous_block']))
 655             attempts += bitcoin_data.target_to_average_attempts(share.target)
 656             this_score = attempts//(ht.get_highest_height() - max_height + 1)
 657             if this_score > score2:
 658                 score2 = this_score
 659         return min(head_height, self.net.CHAIN_LENGTH), score2
 660
 661 def format_hash(x):
 662     if x is None:
 663         return 'xxxxxxxx'
 664     return '%08x' % (x % 2**32)
 665
 666 class ShareStore(object):
 667     def __init__(self, prefix, net):
 668         self.filename = prefix
 669         self.dirname = os.path.dirname(os.path.abspath(prefix))
 670         self.filename = os.path.basename(os.path.abspath(prefix))
 671         self.net = net
 672         self.known = None # will be filename -> set of share hashes, set of verified hashes
 673
 674     def get_shares(self):
 675         if self.known is not None:
 676             raise AssertionError()
 677         known = {}
 678         filenames, next = self.get_filenames_and_next()
 679         for filename in filenames:
 680             share_hashes, verified_hashes = known.setdefault(filename, (set(), set()))
 681             with open(filename, 'rb') as f:
 682                 for line in f:
 683                     try:
 684                         type_id_str, data_hex = line.strip().split(' ')
 685                         type_id = int(type_id_str)
 686                         if type_id == 0:
 687                             share = Share.from_share1a(share1a_type.unpack(data_hex.decode('hex')), self.net)
 688                             yield 'share', share
 689                             share_hashes.add(share.hash)
 690                         elif type_id == 1:
 691                             share = Share.from_share1b(share1b_type.unpack(data_hex.decode('hex')), self.net)
 692                             yield 'share', share
 693                             share_hashes.add(share.hash)
 694                         elif type_id == 2:
 695                             verified_hash = int(data_hex, 16)
 696                             yield 'verified_hash', verified_hash
 697                             verified_hashes.add(verified_hash)
 698                         elif type_id == 5:
 699                             share = NewShare.from_share(new_share_type.unpack(data_hex.decode('hex')), self.net)
 700                             yield 'share', share
 701                             share_hashes.add(share.hash)
 702                         else:
 703                             raise NotImplementedError("share type %i" % (type_id,))
 704                     except Exception:
 705                         log.err(None, "Error while reading saved shares, continuing where left off:")
 706         self.known = known
 707
 708     def _add_line(self, line):
 709         filenames, next = self.get_filenames_and_next()
 710         if filenames and os.path.getsize(filenames[-1]) < 10e6:
 711             filename = filenames[-1]
 712         else:
 713             filename = next
 714
 715         with open(filename, 'ab') as f:
 716             f.write(line + '\n')
 717
 718         return filename
 719
 720     def add_share(self, share):
 721         if isinstance(share, NewShare):
 722             type_id, data = 5, new_share_type.pack(share.as_share())
 723         elif share.pow_hash <= share.header['target']:
 724             type_id, data = 1, share1b_type.pack(share.as_share1b())
 725         else:
 726             type_id, data = 0, share1a_type.pack(share.as_share1a())
 727         filename = self._add_line("%i %s" % (type_id, data.encode('hex')))
 728         share_hashes, verified_hashes = self.known.setdefault(filename, (set(), set()))
 729         share_hashes.add(share.hash)
 730
 731     def add_verified_hash(self, share_hash):
 732         filename = self._add_line("%i %x" % (2, share_hash))
 733         share_hashes, verified_hashes = self.known.setdefault(filename, (set(), set()))
 734         verified_hashes.add(share_hash)
 735
 736     def get_filenames_and_next(self):
 737         suffixes = sorted(int(x[len(self.filename):]) for x in os.listdir(self.dirname) if x.startswith(self.filename) and x[len(self.filename):].isdigit())
 738         return [os.path.join(self.dirname, self.filename + str(suffix)) for suffix in suffixes], os.path.join(self.dirname, self.filename + (str(suffixes[-1] + 1) if suffixes else str(0)))
 739
 740     def forget_share(self, share_hash):
 741         for filename, (share_hashes, verified_hashes) in self.known.iteritems():
 742             if share_hash in share_hashes:
 743                 share_hashes.remove(share_hash)
 744         self.check_remove()
 745
 746     def forget_verified_share(self, share_hash):
 747         for filename, (share_hashes, verified_hashes) in self.known.iteritems():
 748             if share_hash in verified_hashes:
 749                 verified_hashes.remove(share_hash)
 750         self.check_remove()
 751
 752     def check_remove(self):
 753         to_remove = set()
 754         for filename, (share_hashes, verified_hashes) in self.known.iteritems():
 755             #print filename, len(share_hashes) + len(verified_hashes)
 756             if not share_hashes and not verified_hashes:
 757                 to_remove.add(filename)
 758         for filename in to_remove:
 759             self.known.pop(filename)
 760             os.remove(filename)
 761             print "REMOVED", filename
 762
 763 class BitcoinMainnet(networks.BitcoinMainnet):
 764     SHARE_PERIOD = 10 # seconds
 765     CHAIN_LENGTH = 24*60*60//5 # shares
 766     TARGET_LOOKBEHIND = 200 # shares
 767     SPREAD = 3 # blocks
 768     SCRIPT = '4104ffd03de44a6e11b9917f3a29f9443283d9871c9d743ef30d5eddcd37094b64d1b3d8090496b53256786bf5c82932ec23c3b74d9f05a6f95a8b5529352656664bac'.decode('hex')
 769     IDENTIFIER = 'fc70035c7a81bc6f'.decode('hex')
 770     PREFIX = '2472ef181efcd37b'.decode('hex')
 771     NAME = 'bitcoin'
 772     P2P_PORT = 9333
 773     MAX_TARGET = 2**256//2**32 - 1
 774     PERSIST = False
 775     WORKER_PORT = 9332
 776
 777 class BitcoinTestnet(networks.BitcoinTestnet):
 778     SHARE_PERIOD = 1 # seconds
 779     CHAIN_LENGTH = 24*60*60//5 # shares
 780     TARGET_LOOKBEHIND = 200 # shares
 781     SPREAD = 3 # blocks
 782     SCRIPT = '410403ad3dee8ab3d8a9ce5dd2abfbe7364ccd9413df1d279bf1a207849310465b0956e5904b1155ecd17574778f9949589ebfd4fb33ce837c241474a225cf08d85dac'.decode('hex')
 783     IDENTIFIER = '5fc2be2d4f0d6bfb'.decode('hex')
 784     PREFIX = '3f6057a15036f441'.decode('hex')
 785     NAME = 'bitcoin_testnet'
 786     P2P_PORT = 19333
 787     MAX_TARGET = 2**256//2**32 - 1
 788     PERSIST = False
 789     WORKER_PORT = 19332
 790
 791 class NamecoinMainnet(networks.NamecoinMainnet):
 792     SHARE_PERIOD = 10 # seconds
 793     CHAIN_LENGTH = 24*60*60//10 # shares
 794     TARGET_LOOKBEHIND = 3600//10 # shares
 795     SPREAD = 3 # blocks
 796     SCRIPT = '41043da5beb73f8f18cede1a41b0ed953123f1342b8e0216ab5bf71ed3e024201b4017f472bddb6041f17978d89ed8f8ed84f9e726b0bca80cacf96347c7153e8df0ac'.decode('hex')
 797     IDENTIFIER = 'd5b1192062c4c454'.decode('hex')
 798     PREFIX = 'b56f3d0fb24fc982'.decode('hex')
 799     NAME = 'namecoin'
 800     P2P_PORT = 9334
 801     MAX_TARGET = 2**256//2**32 - 1
 802     PERSIST = True
 803     WORKER_PORT = 9331
 804
 805 class NamecoinTestnet(networks.NamecoinTestnet):
 806     SHARE_PERIOD = 1 # seconds
 807     CHAIN_LENGTH = 24*60*60//5 # shares
 808     TARGET_LOOKBEHIND = 200 # shares
 809     SPREAD = 3 # blocks
 810     SCRIPT = '410403ad3dee8ab3d8a9ce5dd2abfbe7364ccd9413df1d279bf1a207849310465b0956e5904b1155ecd17574778f9949589ebfd4fb33ce837c241474a225cf08d85dac'.decode('hex')
 811     IDENTIFIER = '8dd303d014a01a60'.decode('hex')
 812     PREFIX = '4d6581d24f51acbf'.decode('hex')
 813     NAME = 'namecoin_testnet'
 814     P2P_PORT = 19334
 815     MAX_TARGET = 2**256//2**20 - 1
 816     PERSIST = False
 817     WORKER_PORT = 19331
 818
 819 class IxcoinMainnet(networks.IxcoinMainnet):
 820     SHARE_PERIOD = 10 # seconds
 821     CHAIN_LENGTH = 24*60*60//10 # shares
 822     TARGET_LOOKBEHIND = 3600//10 # shares
 823     SPREAD = 3 # blocks
 824     SCRIPT = '41043da5beb73f8f18cede1a41b0ed953123f1342b8e0216ab5bf71ed3e024201b4017f472bddb6041f17978d89ed8f8ed84f9e726b0bca80cacf96347c7153e8df0ac'.decode('hex')
 825     IDENTIFIER = '27b564116e2a2666'.decode('hex')
 826     PREFIX = '9dd6c4a619401f2f'.decode('hex')
 827     NAME = 'ixcoin'
 828     P2P_PORT = 9335
 829     MAX_TARGET = 2**256//2**32 - 1
 830     PERSIST = True
 831     WORKER_PORT = 9330
 832
 833 class IxcoinTestnet(networks.IxcoinTestnet):
 834     SHARE_PERIOD = 1 # seconds
 835     CHAIN_LENGTH = 24*60*60//5 # shares
 836     TARGET_LOOKBEHIND = 200 # shares
 837     SPREAD = 3 # blocks
 838     SCRIPT = '410403ad3dee8ab3d8a9ce5dd2abfbe7364ccd9413df1d279bf1a207849310465b0956e5904b1155ecd17574778f9949589ebfd4fb33ce837c241474a225cf08d85dac'.decode('hex')
 839     IDENTIFIER = '7430cbeb01249e44'.decode('hex')
 840     PREFIX = '7cfffda946709c1f'.decode('hex')
 841     NAME = 'ixcoin_testnet'
 842     P2P_PORT = 19335
 843     MAX_TARGET = 2**256//2**20 - 1
 844     PERSIST = False
 845     WORKER_PORT = 19330
 846
 847 class I0coinMainnet(networks.I0coinMainnet):
 848     SHARE_PERIOD = 10 # seconds
 849     CHAIN_LENGTH = 24*60*60//10 # shares
 850     TARGET_LOOKBEHIND = 3600//10 # shares
 851     SPREAD = 3 # blocks
 852     SCRIPT = '410403ad3dee8ab3d8a9ce5dd2abfbe7364ccd9413df1d279bf1a207849310465b0956e5904b1155ecd17574778f9949589ebfd4fb33ce837c241474a225cf08d85dac'.decode('hex')
 853     IDENTIFIER = 'b32e3f10c2ff221b'.decode('hex')
 854     PREFIX = '6155537ed977a3b5'.decode('hex')
 855     NAME = 'i0coin'
 856     P2P_PORT = 9336
 857     MAX_TARGET = 2**256//2**32 - 1
 858     PERSIST = False
 859     WORKER_PORT = 9329
 860
 861 class I0coinTestnet(networks.I0coinTestnet):
 862     SHARE_PERIOD = 1 # seconds
 863     CHAIN_LENGTH = 24*60*60//5 # shares
 864     TARGET_LOOKBEHIND = 200 # shares
 865     SPREAD = 3 # blocks
 866     SCRIPT = '410403ad3dee8ab3d8a9ce5dd2abfbe7364ccd9413df1d279bf1a207849310465b0956e5904b1155ecd17574778f9949589ebfd4fb33ce837c241474a225cf08d85dac'.decode('hex')
 867     IDENTIFIER = '7712c1a8181b5f2e'.decode('hex')
 868     PREFIX = '792d2e7d770fbe68'.decode('hex')
 869     NAME = 'i0coin_testnet'
 870     P2P_PORT = 19336
 871     MAX_TARGET = 2**256//2**20 - 1
 872     PERSIST = False
 873     WORKER_PORT = 19329
 874
 875 class SolidcoinMainnet(networks.SolidcoinMainnet):
 876     SHARE_PERIOD = 10
 877     CHAIN_LENGTH = 24*60*60//10 # shares
 878     TARGET_LOOKBEHIND = 3600//10 # shares
 879     SPREAD = 3 # blocks
 880     SCRIPT = bitcoin_data.pubkey_hash_to_script2(bitcoin_data.address_to_pubkey_hash('sMKZ1yxHETxPYKh4Z2anWnwZDJZU7ztroy', networks.SolidcoinMainnet))
 881     IDENTIFIER = '9cc9c421cca258cd'.decode('hex')
 882     PREFIX = 'c059125b8070f00a'.decode('hex')
 883     NAME = 'solidcoin'
 884     P2P_PORT = 9337
 885     MAX_TARGET = 2**256//2**32 - 1
 886     PERSIST = True
 887     WORKER_PORT = 9328
 888
 889 class LitecoinMainnet(networks.LitecoinMainnet):
 890     SHARE_PERIOD = 10 # seconds
 891     CHAIN_LENGTH = 24*60*60//5 # shares
 892     TARGET_LOOKBEHIND = 200 # shares
 893     SPREAD = 12 # blocks
 894     SCRIPT = None # no fee
 895     IDENTIFIER = 'e037d5b8c6923410'.decode('hex')
 896     PREFIX = '7208c1a53ef629b0'.decode('hex')
 897     NAME = 'litecoin'
 898     P2P_PORT = 9338
 899     MAX_TARGET = 2**256//2**20 - 1
 900     PERSIST = True
 901     WORKER_PORT = 9327
 902
 903 class LitecoinTestnet(networks.LitecoinTestnet):
 904     SHARE_PERIOD = 1 # seconds
 905     CHAIN_LENGTH = 24*60*60//5 # shares
 906     TARGET_LOOKBEHIND = 200 # shares
 907     SPREAD = 12 # blocks
 908     SCRIPT = None # no fee
 909     IDENTIFIER = 'cca5e24ec6408b1e'.decode('hex')
 910     PREFIX = 'ad9614f6466a39cf'.decode('hex')
 911     NAME = 'litecoin_testnet'
 912     P2P_PORT = 19338
 913     MAX_TARGET = 2**256//2**17 - 1
 914     PERSIST = False
 915     WORKER_PORT = 19327
 916
 917 nets = dict((net.NAME, net) for net in set([BitcoinMainnet, BitcoinTestnet, NamecoinMainnet, NamecoinTestnet, IxcoinMainnet, IxcoinTestnet, I0coinMainnet, I0coinTestnet, SolidcoinMainnet, LitecoinMainnet, LitecoinTestnet]))