p2pool/data.py

   1 from __future__ import division
   2
   3 import hashlib
   4 import os
   5 import random
   6 import sys
   7 import time
   8
   9 from twisted.python import log
  10
  11 import p2pool
  12 from p2pool.bitcoin import data as bitcoin_data, script, sha256
  13 from p2pool.util import math, forest, pack
  14
  15 # hashlink
  16
  17 hash_link_type = pack.ComposedType([
  18     ('state', pack.FixedStrType(32)),
  19     ('extra_data', pack.FixedStrType(0)), # bit of a hack, but since the donation script is at the end, const_ending is long enough to always make this empty
  20     ('length', pack.VarIntType()),
  21 ])
  22
  23 def prefix_to_hash_link(prefix, const_ending=''):
  24     assert prefix.endswith(const_ending), (prefix, const_ending)
  25     x = sha256.sha256(prefix)
  26     return dict(state=x.state, extra_data=x.buf[:max(0, len(x.buf)-len(const_ending))], length=x.length//8)
  27
  28 def check_hash_link(hash_link, data, const_ending=''):
  29     extra_length = hash_link['length'] % (512//8)
  30     assert len(hash_link['extra_data']) == max(0, extra_length - len(const_ending))
  31     extra = (hash_link['extra_data'] + const_ending)[len(hash_link['extra_data']) + len(const_ending) - extra_length:]
  32     assert len(extra) == extra_length
  33     return pack.IntType(256).unpack(hashlib.sha256(sha256.sha256(data, (hash_link['state'], extra, 8*hash_link['length'])).digest()).digest())
  34
  35 # shares
  36
  37 share_type = pack.ComposedType([
  38     ('type', pack.VarIntType()),
  39     ('contents', pack.VarStrType()),
  40 ])
  41
  42 def load_share(share, net, peer):
  43     if share['type'] in [0, 1, 2, 3]:
  44         from p2pool import p2p
  45         raise p2p.PeerMisbehavingError('sent an obsolete share')
  46     elif share['type'] == 4:
  47         return Share(net, peer, other_txs=None, **Share.share1a_type.unpack(share['contents']))
  48     elif share['type'] == 5:
  49         share1b = Share.share1b_type.unpack(share['contents'])
  50         return Share(net, peer, merkle_link=bitcoin_data.calculate_merkle_link([0] + [bitcoin_data.hash256(bitcoin_data.tx_type.pack(x)) for x in share1b['other_txs']], 0), **share1b)
  51     elif share['type'] == NewShare.VERSION:
  52         return NewShare(net, peer, NewShare.share_type.unpack(share['contents']))
  53     elif share['type'] == NewNewShare.VERSION:
  54         return NewNewShare(net, peer, NewNewShare.share_type.unpack(share['contents']))
  55     else:
  56         raise ValueError('unknown share type: %r' % (share['type'],))
  57
  58 DONATION_SCRIPT = '4104ffd03de44a6e11b9917f3a29f9443283d9871c9d743ef30d5eddcd37094b64d1b3d8090496b53256786bf5c82932ec23c3b74d9f05a6f95a8b5529352656664bac'.decode('hex')
  59
  60 class NewNewShare(object):
  61     VERSION = 9
  62     SUCCESSOR = None
  63
  64     other_txs = None
  65
  66     small_block_header_type = pack.ComposedType([
  67         ('version', pack.VarIntType()),
  68         ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))),
  69         ('timestamp', pack.IntType(32)),
  70         ('bits', bitcoin_data.FloatingIntegerType()),
  71         ('nonce', pack.IntType(32)),
  72     ])
  73
  74     share_info_type = pack.ComposedType([
  75         ('share_data', pack.ComposedType([
  76             ('previous_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
  77             ('coinbase', pack.VarStrType()),
  78             ('nonce', pack.IntType(32)),
  79             ('pubkey_hash', pack.IntType(160)),
  80             ('subsidy', pack.IntType(64)),
  81             ('donation', pack.IntType(16)),
  82             ('stale_info', pack.EnumType(pack.IntType(8), dict((k, {0: None, 253: 'orphan', 254: 'doa'}.get(k, 'unk%i' % (k,))) for k in xrange(256)))),
  83             ('desired_version', pack.VarIntType()),
  84         ])),
  85         ('new_transaction_hashes', pack.ListType(pack.IntType(256))),
  86         ('transaction_hash_refs', pack.ListType(pack.ComposedType([ # compressed by referencing previous shares' hashes
  87             ('share_count', pack.VarIntType()),
  88             ('tx_count', pack.VarIntType()),
  89         ]))),
  90         ('far_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
  91         ('max_bits', bitcoin_data.FloatingIntegerType()),
  92         ('bits', bitcoin_data.FloatingIntegerType()),
  93         ('timestamp', pack.IntType(32)),
  94     ])
  95
  96     share_type = pack.ComposedType([
  97         ('min_header', small_block_header_type),
  98         ('share_info', share_info_type),
  99         ('ref_merkle_link', pack.ComposedType([
 100             ('branch', pack.ListType(pack.IntType(256))),
 101             ('index', pack.IntType(0)),
 102         ])),
 103         ('last_txout_nonce', pack.IntType(32)),
 104         ('hash_link', hash_link_type),
 105         ('merkle_link', pack.ComposedType([
 106             ('branch', pack.ListType(pack.IntType(256))),
 107             ('index', pack.IntType(0)), # it will always be 0
 108         ])),
 109     ])
 110
 111     ref_type = pack.ComposedType([
 112         ('identifier', pack.FixedStrType(64//8)),
 113         ('share_info', share_info_type),
 114     ])
 115
 116     gentx_before_refhash = pack.VarStrType().pack(DONATION_SCRIPT) + pack.IntType(64).pack(0) + pack.VarStrType().pack('\x24' + pack.IntType(256).pack(0) + pack.IntType(32).pack(0))[:2]
 117
 118     @classmethod
 119     def generate_transaction(cls, tracker, share_data, block_target, desired_timestamp, desired_target, ref_merkle_link, desired_other_transaction_hashes, net, known_txs=None, last_txout_nonce=0):
 120         previous_share = tracker.items[share_data['previous_share_hash']] if share_data['previous_share_hash'] is not None else None
 121
 122         height, last = tracker.get_height_and_last(share_data['previous_share_hash'])
 123         assert height >= net.REAL_CHAIN_LENGTH or last is None
 124         if height < net.TARGET_LOOKBEHIND:
 125             pre_target3 = net.MAX_TARGET
 126         else:
 127             attempts_per_second = get_pool_attempts_per_second(tracker, share_data['previous_share_hash'], net.TARGET_LOOKBEHIND, min_work=True, integer=True)
 128             pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1 if attempts_per_second else 2**256-1
 129             pre_target2 = math.clip(pre_target, (previous_share.max_target*9//10, previous_share.max_target*11//10))
 130             pre_target3 = math.clip(pre_target2, (net.MIN_TARGET, net.MAX_TARGET))
 131         max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
 132         bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//10, pre_target3)))
 133
 134         weights, total_weight, donation_weight = tracker.get_cumulative_weights(share_data['previous_share_hash'],
 135             min(height, net.REAL_CHAIN_LENGTH),
 136             65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target),
 137         )
 138         assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
 139
 140         amounts = dict((script, share_data['subsidy']*(199*weight)//(200*total_weight)) for script, weight in weights.iteritems()) # 99.5% goes according to weights prior to this share
 141         this_script = bitcoin_data.pubkey_hash_to_script2(share_data['pubkey_hash'])
 142         amounts[this_script] = amounts.get(this_script, 0) + share_data['subsidy']//200 # 0.5% goes to block finder
 143         amounts[DONATION_SCRIPT] = amounts.get(DONATION_SCRIPT, 0) + share_data['subsidy'] - sum(amounts.itervalues()) # all that's left over is the donation weight and some extra satoshis due to rounding
 144
 145         if sum(amounts.itervalues()) != share_data['subsidy'] or any(x < 0 for x in amounts.itervalues()):
 146             raise ValueError()
 147
 148         dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit
 149
 150         new_transaction_hashes = []
 151         new_transaction_size = 0
 152         transaction_hash_refs = []
 153         other_transaction_hashes = []
 154
 155         for tx_hash in desired_other_transaction_hashes:
 156             for i, share in enumerate(tracker.get_chain(share_data['previous_share_hash'], min(height, 100))):
 157                 if tx_hash in share.new_transaction_hashes:
 158                     this = dict(share_count=i+1, tx_count=share.new_transaction_hashes.index(tx_hash))
 159                     break
 160             else:
 161                 if known_txs is not None:
 162                     this_size = bitcoin_data.tx_type.packed_size(known_txs[tx_hash])
 163                     if new_transaction_size + this_size > 50000: # only allow 50 kB of new txns/share
 164                         break
 165                     new_transaction_size += this_size
 166                 new_transaction_hashes.append(tx_hash)
 167                 this = dict(share_count=0, tx_count=len(new_transaction_hashes)-1)
 168             transaction_hash_refs.append(this)
 169             other_transaction_hashes.append(tx_hash)
 170
 171         share_info = dict(
 172             share_data=share_data,
 173             far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
 174             max_bits=max_bits,
 175             bits=bits,
 176             timestamp=math.clip(desired_timestamp, (
 177                 (previous_share.timestamp + net.SHARE_PERIOD) - (net.SHARE_PERIOD - 1), # = previous_share.timestamp + 1
 178                 (previous_share.timestamp + net.SHARE_PERIOD) + (net.SHARE_PERIOD - 1),
 179             )) if previous_share is not None else desired_timestamp,
 180             new_transaction_hashes=new_transaction_hashes,
 181             transaction_hash_refs=transaction_hash_refs,
 182         )
 183
 184         gentx = dict(
 185             version=1,
 186             tx_ins=[dict(
 187                 previous_output=None,
 188                 sequence=None,
 189                 script=share_data['coinbase'],
 190             )],
 191             tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT] + [dict(
 192                 value=0,
 193                 script='\x24' + cls.get_ref_hash(net, share_info, ref_merkle_link) + pack.IntType(32).pack(last_txout_nonce),
 194             )],
 195             lock_time=0,
 196         )
 197
 198         def get_share(header, transactions):
 199             min_header=dict(header);del min_header['merkle_root']
 200             return cls(net, None, dict(
 201                 min_header=min_header,
 202                 share_info=share_info,
 203                 ref_merkle_link=dict(branch=[], index=0),
 204                 last_txout_nonce=last_txout_nonce,
 205                 hash_link=prefix_to_hash_link(bitcoin_data.tx_type.pack(gentx)[:-32-4-4], cls.gentx_before_refhash),
 206                 merkle_link=bitcoin_data.calculate_merkle_link([None] + other_transaction_hashes, 0),
 207             ))
 208
 209         return share_info, gentx, other_transaction_hashes, get_share
 210
 211     @classmethod
 212     def get_ref_hash(cls, net, share_info, ref_merkle_link):
 213         return pack.IntType(256).pack(bitcoin_data.check_merkle_link(bitcoin_data.hash256(cls.ref_type.pack(dict(
 214             identifier=net.IDENTIFIER,
 215             share_info=share_info,
 216         ))), ref_merkle_link))
 217
 218     __slots__ = 'net peer contents min_header share_info hash_link merkle_link hash share_data max_target target timestamp previous_hash new_script desired_version gentx_hash header pow_hash header_hash new_transaction_hashes time_seen'.split(' ')
 219
 220     def __init__(self, net, peer, contents):
 221         self.net = net
 222         self.peer = peer
 223         self.contents = contents
 224
 225         self.min_header = contents['min_header']
 226         self.share_info = contents['share_info']
 227         self.hash_link = contents['hash_link']
 228         self.merkle_link = contents['merkle_link']
 229
 230         if not (2 <= len(self.share_info['share_data']['coinbase']) <= 100):
 231             raise ValueError('''bad coinbase size! %i bytes''' % (len(self.share_info['share_data']['coinbase']),))
 232
 233         if len(self.merkle_link['branch']) > 16:
 234             raise ValueError('merkle branch too long!')
 235
 236         assert not self.hash_link['extra_data'], repr(self.hash_link['extra_data'])
 237
 238         self.share_data = self.share_info['share_data']
 239         self.max_target = self.share_info['max_bits'].target
 240         self.target = self.share_info['bits'].target
 241         self.timestamp = self.share_info['timestamp']
 242         self.previous_hash = self.share_data['previous_share_hash']
 243         self.new_script = bitcoin_data.pubkey_hash_to_script2(self.share_data['pubkey_hash'])
 244         self.desired_version = self.share_data['desired_version']
 245
 246         for x in self.share_info['transaction_hash_refs']:
 247             assert x['share_count'] < 110
 248         for i, x in enumerate(self.share_info['new_transaction_hashes']):
 249             assert dict(share_count=0, tx_count=i) in self.share_info['transaction_hash_refs']
 250
 251         self.gentx_hash = check_hash_link(
 252             self.hash_link,
 253             self.get_ref_hash(net, self.share_info, contents['ref_merkle_link']) + pack.IntType(32).pack(self.contents['last_txout_nonce']) + pack.IntType(32).pack(0),
 254             self.gentx_before_refhash,
 255         )
 256         merkle_root = bitcoin_data.check_merkle_link(self.gentx_hash, self.merkle_link)
 257         self.header = dict(self.min_header, merkle_root=merkle_root)
 258         self.pow_hash = net.PARENT.POW_FUNC(bitcoin_data.block_header_type.pack(self.header))
 259         self.hash = self.header_hash = bitcoin_data.hash256(bitcoin_data.block_header_type.pack(self.header))
 260
 261         if self.target > net.MAX_TARGET:
 262             from p2pool import p2p
 263             raise p2p.PeerMisbehavingError('share target invalid')
 264
 265         if self.pow_hash > self.target:
 266             from p2pool import p2p
 267             raise p2p.PeerMisbehavingError('share PoW invalid')
 268
 269         self.new_transaction_hashes = self.share_info['new_transaction_hashes']
 270
 271         # XXX eww
 272         self.time_seen = time.time()
 273
 274     def __repr__(self):
 275         return 'Share' + repr((self.net, self.peer, self.contents))
 276
 277     def as_share(self):
 278         return dict(type=self.VERSION, contents=self.share_type.pack(self.contents))
 279
 280     def check(self, tracker):
 281         from p2pool import p2p
 282         if self.share_data['previous_share_hash'] is not None:
 283             previous_share = tracker.items[self.share_data['previous_share_hash']]
 284             if type(self) is type(previous_share):
 285                 pass
 286             elif type(self) is type(previous_share).SUCCESSOR:
 287                 if tracker.get_height(previous_share.hash) < self.net.CHAIN_LENGTH:
 288                     from p2pool import p2p
 289                     raise p2p.PeerMisbehavingError('switch without enough history')
 290
 291                 # switch only valid if 85% of hashes in [self.net.CHAIN_LENGTH*9//10, self.net.CHAIN_LENGTH] for new version
 292                 counts = get_desired_version_counts(tracker,
 293                     tracker.get_nth_parent_hash(previous_share.hash, self.net.CHAIN_LENGTH*9//10), self.net.CHAIN_LENGTH//10)
 294                 if counts.get(self.VERSION, 0) < sum(counts.itervalues())*85//100:
 295                     raise p2p.PeerMisbehavingError('switch without enough hash power upgraded')
 296             else:
 297                 raise p2p.PeerMisbehavingError('''%s can't follow %s''' % (type(self).__name__, type(previous_share).__name__))
 298
 299         other_tx_hashes = [tracker.items[tracker.get_nth_parent_hash(self.hash, x['share_count'])].share_info['new_transaction_hashes'][x['tx_count']] for x in self.share_info['transaction_hash_refs']]
 300
 301         share_info, gentx, other_tx_hashes2, get_share = self.generate_transaction(tracker, self.share_info['share_data'], self.header['bits'].target, self.share_info['timestamp'], self.share_info['bits'].target, self.contents['ref_merkle_link'], other_tx_hashes, self.net, last_txout_nonce=self.contents['last_txout_nonce'])
 302         assert other_tx_hashes2 == other_tx_hashes
 303         if share_info != self.share_info:
 304             raise ValueError('share_info invalid')
 305         if bitcoin_data.hash256(bitcoin_data.tx_type.pack(gentx)) != self.gentx_hash:
 306             raise ValueError('''gentx doesn't match hash_link''')
 307
 308         if bitcoin_data.calculate_merkle_link([None] + other_tx_hashes, 0) != self.merkle_link:
 309             raise ValueError('merkle_link and other_tx_hashes do not match')
 310
 311         return gentx # only used by as_block
 312
 313     def get_other_tx_hashes(self, tracker):
 314         if tracker.get_height(self.hash) <= max(x['share_count'] for x in self.share_info['transaction_hash_refs']):
 315             return None
 316         return [tracker.items[tracker.get_nth_parent_hash(self.hash, x['share_count'])].share_info['new_transaction_hashes'][x['tx_count']] for x in self.share_info['transaction_hash_refs']]
 317
 318     def _get_other_txs(self, tracker, known_txs):
 319         other_tx_hashes = self.get_other_tx_hashes(tracker)
 320         if other_tx_hashes is None:
 321             return None # not all parents present
 322
 323         if not all(tx_hash in known_txs for tx_hash in other_tx_hashes):
 324             return None # not all txs present
 325
 326         return [known_txs[tx_hash] for tx_hash in other_tx_hashes]
 327
 328     def should_punish_reason(self, previous_block, bits, tracker, known_txs):
 329         if (self.header['previous_block'], self.header['bits']) != (previous_block, bits) and self.header_hash != previous_block and self.peer is not None:
 330             return True, 'Block-stale detected! %x < %x' % (self.header['previous_block'], previous_block)
 331
 332         if self.pow_hash <= self.header['bits'].target:
 333             return -1, 'block solution'
 334
 335         other_txs = self._get_other_txs(tracker, known_txs)
 336         if other_txs is None:
 337             return True, 'not all txs present'
 338         else:
 339             all_txs_size = sum(bitcoin_data.tx_type.packed_size(tx) for tx in other_txs)
 340             if all_txs_size > 1000000:
 341                 return True, 'txs over block size limit'
 342
 343             new_txs_size = sum(bitcoin_data.tx_type.packed_size(known_txs[tx_hash]) for tx_hash in self.share_info['new_transaction_hashes'])
 344             if new_txs_size > 50000:
 345                 return True, 'new txs over limit'
 346
 347         return False, None
 348
 349     def as_block(self, tracker, known_txs):
 350         other_txs = self._get_other_txs(tracker, known_txs)
 351         if other_txs is None:
 352             return None # not all txs present
 353         return dict(header=self.header, txs=[self.check(tracker)] + other_txs)
 354
 355 class Share(object):
 356     VERSION = 7
 357     SUCCESSOR = NewNewShare
 358
 359     small_block_header_type = pack.ComposedType([
 360         ('version', pack.VarIntType()), # XXX must be constrained to 32 bits
 361         ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))),
 362         ('timestamp', pack.IntType(32)),
 363         ('bits', bitcoin_data.FloatingIntegerType()),
 364         ('nonce', pack.IntType(32)),
 365     ])
 366
 367     share_data_type = pack.ComposedType([
 368         ('previous_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
 369         ('coinbase', pack.VarStrType()),
 370         ('nonce', pack.IntType(32)),
 371         ('pubkey_hash', pack.IntType(160)),
 372         ('subsidy', pack.IntType(64)),
 373         ('donation', pack.IntType(16)),
 374         ('stale_info', pack.EnumType(pack.IntType(8), dict((k, {0: None, 253: 'orphan', 254: 'doa'}.get(k, 'unk%i' % (k,))) for k in xrange(256)))),
 375         ('desired_version', pack.VarIntType()),
 376     ])
 377
 378     share_info_type = pack.ComposedType([
 379         ('share_data', share_data_type),
 380         ('far_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
 381         ('max_bits', bitcoin_data.FloatingIntegerType()),
 382         ('bits', bitcoin_data.FloatingIntegerType()),
 383         ('timestamp', pack.IntType(32)),
 384     ])
 385
 386     share_common_type = pack.ComposedType([
 387         ('min_header', small_block_header_type),
 388         ('share_info', share_info_type),
 389         ('ref_merkle_link', pack.ComposedType([
 390             ('branch', pack.ListType(pack.IntType(256))),
 391             ('index', pack.VarIntType()),
 392         ])),
 393         ('hash_link', hash_link_type),
 394     ])
 395     share1a_type = pack.ComposedType([
 396         ('common', share_common_type),
 397         ('merkle_link', pack.ComposedType([
 398             ('branch', pack.ListType(pack.IntType(256))),
 399             ('index', pack.IntType(0)), # it will always be 0
 400         ])),
 401     ])
 402     share1b_type = pack.ComposedType([
 403         ('common', share_common_type),
 404         ('other_txs', pack.ListType(bitcoin_data.tx_type)),
 405     ])
 406
 407     ref_type = pack.ComposedType([
 408         ('identifier', pack.FixedStrType(64//8)),
 409         ('share_info', share_info_type),
 410     ])
 411
 412     gentx_before_refhash = pack.VarStrType().pack(DONATION_SCRIPT) + pack.IntType(64).pack(0) + pack.VarStrType().pack('\x20' + pack.IntType(256).pack(0))[:2]
 413
 414     @classmethod
 415     def generate_transaction(cls, tracker, share_data, block_target, desired_timestamp, desired_target, ref_merkle_link, desired_other_transaction_hashes, net, known_txs=None):
 416         previous_share = tracker.items[share_data['previous_share_hash']] if share_data['previous_share_hash'] is not None else None
 417
 418         height, last = tracker.get_height_and_last(share_data['previous_share_hash'])
 419         assert height >= net.REAL_CHAIN_LENGTH or last is None
 420         if height < net.TARGET_LOOKBEHIND:
 421             pre_target3 = net.MAX_TARGET
 422         else:
 423             attempts_per_second = get_pool_attempts_per_second(tracker, share_data['previous_share_hash'], net.TARGET_LOOKBEHIND, min_work=True, integer=True)
 424             pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1 if attempts_per_second else 2**256-1
 425             pre_target2 = math.clip(pre_target, (previous_share.max_target*9//10, previous_share.max_target*11//10))
 426             pre_target3 = math.clip(pre_target2, (net.MIN_TARGET, net.MAX_TARGET))
 427         max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
 428         bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//10, pre_target3)))
 429
 430         weights, total_weight, donation_weight = tracker.get_cumulative_weights(share_data['previous_share_hash'],
 431             min(height, net.REAL_CHAIN_LENGTH),
 432             65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target),
 433         )
 434         assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
 435
 436         amounts = dict((script, share_data['subsidy']*(199*weight)//(200*total_weight)) for script, weight in weights.iteritems()) # 99.5% goes according to weights prior to this share
 437         this_script = bitcoin_data.pubkey_hash_to_script2(share_data['pubkey_hash'])
 438         amounts[this_script] = amounts.get(this_script, 0) + share_data['subsidy']//200 # 0.5% goes to block finder
 439         amounts[DONATION_SCRIPT] = amounts.get(DONATION_SCRIPT, 0) + share_data['subsidy'] - sum(amounts.itervalues()) # all that's left over is the donation weight and some extra satoshis due to rounding
 440
 441         if sum(amounts.itervalues()) != share_data['subsidy'] or any(x < 0 for x in amounts.itervalues()):
 442             raise ValueError()
 443
 444         dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit
 445
 446         share_info = dict(
 447             share_data=share_data,
 448             far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
 449             max_bits=max_bits,
 450             bits=bits,
 451             timestamp=math.clip(desired_timestamp, (
 452                 (previous_share.timestamp + net.SHARE_PERIOD) - (net.SHARE_PERIOD - 1), # = previous_share.timestamp + 1
 453                 (previous_share.timestamp + net.SHARE_PERIOD) + (net.SHARE_PERIOD - 1),
 454             )) if previous_share is not None else desired_timestamp,
 455         )
 456
 457         gentx = dict(
 458             version=1,
 459             tx_ins=[dict(
 460                 previous_output=None,
 461                 sequence=None,
 462                 script=share_data['coinbase'].ljust(2, '\x00'),
 463             )],
 464             tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT] + [dict(
 465                 value=0,
 466                 script='\x20' + cls.get_ref_hash(net, share_info, ref_merkle_link),
 467             )],
 468             lock_time=0,
 469         )
 470
 471         def get_share(header, transactions):
 472             assert transactions[0] == gentx and [bitcoin_data.hash256(bitcoin_data.tx_type.pack(tx)) for tx in transactions[1:]] == desired_other_transaction_hashes
 473             min_header = dict(header);del min_header['merkle_root']
 474             hash_link = prefix_to_hash_link(bitcoin_data.tx_type.pack(gentx)[:-32-4], cls.gentx_before_refhash)
 475             merkle_link = bitcoin_data.calculate_merkle_link([None] + desired_other_transaction_hashes, 0)
 476             pow_hash = net.PARENT.POW_FUNC(bitcoin_data.block_header_type.pack(header))
 477             return cls(net, None, dict(
 478                 min_header=min_header, share_info=share_info, hash_link=hash_link,
 479                 ref_merkle_link=dict(branch=[], index=0),
 480             ), merkle_link=merkle_link, other_txs=transactions[1:] if pow_hash <= header['bits'].target else None)
 481
 482         return share_info, gentx, desired_other_transaction_hashes, get_share
 483
 484     @classmethod
 485     def get_ref_hash(cls, net, share_info, ref_merkle_link):
 486         return pack.IntType(256).pack(bitcoin_data.check_merkle_link(bitcoin_data.hash256(cls.ref_type.pack(dict(
 487             identifier=net.IDENTIFIER,
 488             share_info=share_info,
 489         ))), ref_merkle_link))
 490
 491     __slots__ = 'net peer common min_header share_info hash_link merkle_link other_txs hash share_data max_target target timestamp previous_hash new_script desired_version gentx_hash header pow_hash header_hash new_transaction_hashes time_seen'.split(' ')
 492
 493     def __init__(self, net, peer, common, merkle_link, other_txs):
 494         self.net = net
 495         self.peer = peer
 496         self.common = common
 497         self.min_header = common['min_header']
 498         self.share_info = common['share_info']
 499         self.hash_link = common['hash_link']
 500         self.merkle_link = merkle_link
 501         self.other_txs = other_txs
 502
 503         if len(self.share_info['share_data']['coinbase']) > 100:
 504             raise ValueError('''coinbase too large! %i bytes''' % (len(self.share_info['share_data']['coinbase']),))
 505
 506         if len(merkle_link['branch']) > 16:
 507             raise ValueError('merkle branch too long!')
 508
 509         if p2pool.DEBUG and other_txs is not None and bitcoin_data.calculate_merkle_link([0] + [bitcoin_data.hash256(bitcoin_data.tx_type.pack(x)) for x in other_txs], 0) != merkle_link:
 510             raise ValueError('merkle_link and other_txs do not match')
 511
 512         assert not self.hash_link['extra_data'], repr(self.hash_link['extra_data'])
 513
 514         self.share_data = self.share_info['share_data']
 515         self.max_target = self.share_info['max_bits'].target
 516         self.target = self.share_info['bits'].target
 517         self.timestamp = self.share_info['timestamp']
 518         self.previous_hash = self.share_data['previous_share_hash']
 519         self.new_script = bitcoin_data.pubkey_hash_to_script2(self.share_data['pubkey_hash'])
 520         self.desired_version = self.share_data['desired_version']
 521
 522         self.gentx_hash = check_hash_link(
 523             self.hash_link,
 524             self.get_ref_hash(net, self.share_info, common['ref_merkle_link']) + pack.IntType(32).pack(0),
 525             self.gentx_before_refhash,
 526         )
 527         merkle_root = bitcoin_data.check_merkle_link(self.gentx_hash, merkle_link)
 528         self.header = dict(self.min_header, merkle_root=merkle_root)
 529         self.pow_hash = net.PARENT.POW_FUNC(bitcoin_data.block_header_type.pack(self.header))
 530         self.hash = self.header_hash = bitcoin_data.hash256(bitcoin_data.block_header_type.pack(self.header))
 531
 532         if self.pow_hash > self.target:
 533             from p2pool import p2p
 534             raise p2p.PeerMisbehavingError('share PoW invalid')
 535
 536         if other_txs is not None and not self.pow_hash <= self.header['bits'].target:
 537             raise ValueError('other_txs provided when not a block solution')
 538         if other_txs is None and self.pow_hash <= self.header['bits'].target:
 539             raise ValueError('other_txs not provided when a block solution')
 540
 541         self.new_transaction_hashes = []
 542
 543         # XXX eww
 544         self.time_seen = time.time()
 545
 546     def __repr__(self):
 547         return '<Share %s>' % (' '.join('%s=%r' % (k, getattr(self, k)) for k in self.__slots__),)
 548
 549     def as_share1a(self):
 550         return dict(type=4, contents=self.share1a_type.pack(dict(common=self.common, merkle_link=self.merkle_link)))
 551
 552     def as_share1b(self):
 553         return dict(type=5, contents=self.share1b_type.pack(dict(common=self.common, other_txs=self.other_txs)))
 554
 555     def as_share(self):
 556         if not self.pow_hash <= self.header['bits'].target: # share1a
 557             return self.as_share1a()
 558         else:
 559             return self.as_share1b()
 560
 561     def check(self, tracker):
 562         from p2pool import p2p
 563         if self.share_data['previous_share_hash'] is not None:
 564             previous_share = tracker.items[self.share_data['previous_share_hash']]
 565             if type(self) is type(previous_share):
 566                 pass
 567             elif type(self) is type(previous_share).SUCCESSOR:
 568                 if tracker.get_height(previous_share.hash) < self.net.CHAIN_LENGTH:
 569                     from p2pool import p2p
 570                     raise p2p.PeerMisbehavingError('switch without enough history')
 571
 572                 # switch only valid if 85% of hashes in [self.net.CHAIN_LENGTH*9//10, self.net.CHAIN_LENGTH] for new version
 573                 counts = get_desired_version_counts(tracker,
 574                     tracker.get_nth_parent_hash(previous_share.hash, self.net.CHAIN_LENGTH*9//10), self.net.CHAIN_LENGTH//10)
 575                 if counts.get(self.VERSION, 0) < sum(counts.itervalues())*85//100:
 576                     raise p2p.PeerMisbehavingError('switch without enough hash power upgraded')
 577             else:
 578                 raise p2p.PeerMisbehavingError('''%s can't follow %s''' % (type(self).__name__, type(previous_share).__name__))
 579
 580         share_info, gentx, other_transaction_hashes, get_share = self.generate_transaction(tracker, self.share_info['share_data'], self.header['bits'].target, self.share_info['timestamp'], self.share_info['bits'].target, self.common['ref_merkle_link'], [], self.net) # ok because desired_other_transaction_hashes is only used in get_share
 581         if share_info != self.share_info:
 582             raise ValueError('share_info invalid')
 583         if bitcoin_data.hash256(bitcoin_data.tx_type.pack(gentx)) != self.gentx_hash:
 584             raise ValueError('''gentx doesn't match hash_link''')
 585         return gentx # only used by as_block
 586
 587     def get_other_tx_hashes(self, tracker):
 588         return []
 589
 590     def should_punish_reason(self, previous_block, bits, tracker, known_txs):
 591         if (self.header['previous_block'], self.header['bits']) != (previous_block, bits) and self.header_hash != previous_block and self.peer is not None:
 592             return True, 'Block-stale detected! %x < %x' % (self.header['previous_block'], previous_block)
 593
 594         if self.pow_hash <= self.header['bits'].target:
 595             return -1, 'block solution'
 596
 597         return False, None
 598
 599     def as_block(self, tracker, known_txs):
 600         if self.other_txs is None:
 601             raise ValueError('share does not contain all txs')
 602         return dict(header=self.header, txs=[self.check(tracker)] + self.other_txs)
 603
 604 class NewShare(object):
 605     VERSION = 8
 606     SUCCESSOR = NewNewShare
 607
 608     other_txs = None
 609
 610     small_block_header_type = pack.ComposedType([
 611         ('version', pack.VarIntType()),
 612         ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))),
 613         ('timestamp', pack.IntType(32)),
 614         ('bits', bitcoin_data.FloatingIntegerType()),
 615         ('nonce', pack.IntType(32)),
 616     ])
 617
 618     share_info_type = pack.ComposedType([
 619         ('share_data', pack.ComposedType([
 620             ('previous_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
 621             ('coinbase', pack.VarStrType()),
 622             ('nonce', pack.IntType(32)),
 623             ('pubkey_hash', pack.IntType(160)),
 624             ('subsidy', pack.IntType(64)),
 625             ('donation', pack.IntType(16)),
 626             ('stale_info', pack.EnumType(pack.IntType(8), dict((k, {0: None, 253: 'orphan', 254: 'doa'}.get(k, 'unk%i' % (k,))) for k in xrange(256)))),
 627             ('desired_version', pack.VarIntType()),
 628         ])),
 629         ('new_transaction_hashes', pack.ListType(pack.IntType(256))),
 630         ('transaction_hash_refs', pack.ListType(pack.ComposedType([ # compressed by referencing previous shares' hashes
 631             ('share_count', pack.VarIntType()),
 632             ('tx_count', pack.VarIntType()),
 633         ]))),
 634         ('far_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
 635         ('max_bits', bitcoin_data.FloatingIntegerType()),
 636         ('bits', bitcoin_data.FloatingIntegerType()),
 637         ('timestamp', pack.IntType(32)),
 638     ])
 639
 640     share_type = pack.ComposedType([
 641         ('min_header', small_block_header_type),
 642         ('share_info', share_info_type),
 643         ('ref_merkle_link', pack.ComposedType([
 644             ('branch', pack.ListType(pack.IntType(256))),
 645             ('index', pack.IntType(0)),
 646         ])),
 647         ('hash_link', hash_link_type),
 648         ('merkle_link', pack.ComposedType([
 649             ('branch', pack.ListType(pack.IntType(256))),
 650             ('index', pack.IntType(0)), # it will always be 0
 651         ])),
 652     ])
 653
 654     ref_type = pack.ComposedType([
 655         ('identifier', pack.FixedStrType(64//8)),
 656         ('share_info', share_info_type),
 657     ])
 658
 659     gentx_before_refhash = pack.VarStrType().pack(DONATION_SCRIPT) + pack.IntType(64).pack(0) + pack.VarStrType().pack('\x20' + pack.IntType(256).pack(0))[:2]
 660
 661     @classmethod
 662     def generate_transaction(cls, tracker, share_data, block_target, desired_timestamp, desired_target, ref_merkle_link, desired_other_transaction_hashes, net, known_txs=None):
 663         previous_share = tracker.items[share_data['previous_share_hash']] if share_data['previous_share_hash'] is not None else None
 664
 665         height, last = tracker.get_height_and_last(share_data['previous_share_hash'])
 666         assert height >= net.REAL_CHAIN_LENGTH or last is None
 667         if height < net.TARGET_LOOKBEHIND:
 668             pre_target3 = net.MAX_TARGET
 669         else:
 670             attempts_per_second = get_pool_attempts_per_second(tracker, share_data['previous_share_hash'], net.TARGET_LOOKBEHIND, min_work=True, integer=True)
 671             pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1 if attempts_per_second else 2**256-1
 672             pre_target2 = math.clip(pre_target, (previous_share.max_target*9//10, previous_share.max_target*11//10))
 673             pre_target3 = math.clip(pre_target2, (net.MIN_TARGET, net.MAX_TARGET))
 674         max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
 675         bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//10, pre_target3)))
 676
 677         weights, total_weight, donation_weight = tracker.get_cumulative_weights(share_data['previous_share_hash'],
 678             min(height, net.REAL_CHAIN_LENGTH),
 679             65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target),
 680         )
 681         assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
 682
 683         amounts = dict((script, share_data['subsidy']*(199*weight)//(200*total_weight)) for script, weight in weights.iteritems()) # 99.5% goes according to weights prior to this share
 684         this_script = bitcoin_data.pubkey_hash_to_script2(share_data['pubkey_hash'])
 685         amounts[this_script] = amounts.get(this_script, 0) + share_data['subsidy']//200 # 0.5% goes to block finder
 686         amounts[DONATION_SCRIPT] = amounts.get(DONATION_SCRIPT, 0) + share_data['subsidy'] - sum(amounts.itervalues()) # all that's left over is the donation weight and some extra satoshis due to rounding
 687
 688         if sum(amounts.itervalues()) != share_data['subsidy'] or any(x < 0 for x in amounts.itervalues()):
 689             raise ValueError()
 690
 691         dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit
 692
 693         new_transaction_hashes = []
 694         new_transaction_size = 0
 695         transaction_hash_refs = []
 696         other_transaction_hashes = []
 697
 698         for tx_hash in desired_other_transaction_hashes:
 699             for i, share in enumerate(tracker.get_chain(share_data['previous_share_hash'], min(height, 100))):
 700                 if tx_hash in share.new_transaction_hashes:
 701                     this = dict(share_count=i+1, tx_count=share.new_transaction_hashes.index(tx_hash))
 702                     break
 703             else:
 704                 if known_txs is not None:
 705                     this_size = bitcoin_data.tx_type.packed_size(known_txs[tx_hash])
 706                     if new_transaction_size + this_size > 50000: # only allow 50 kB of new txns/share
 707                         break
 708                     new_transaction_size += this_size
 709                 new_transaction_hashes.append(tx_hash)
 710                 this = dict(share_count=0, tx_count=len(new_transaction_hashes)-1)
 711             transaction_hash_refs.append(this)
 712             other_transaction_hashes.append(tx_hash)
 713
 714         share_info = dict(
 715             share_data=share_data,
 716             far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
 717             max_bits=max_bits,
 718             bits=bits,
 719             timestamp=math.clip(desired_timestamp, (
 720                 (previous_share.timestamp + net.SHARE_PERIOD) - (net.SHARE_PERIOD - 1), # = previous_share.timestamp + 1
 721                 (previous_share.timestamp + net.SHARE_PERIOD) + (net.SHARE_PERIOD - 1),
 722             )) if previous_share is not None else desired_timestamp,
 723             new_transaction_hashes=new_transaction_hashes,
 724             transaction_hash_refs=transaction_hash_refs,
 725         )
 726
 727         gentx = dict(
 728             version=1,
 729             tx_ins=[dict(
 730                 previous_output=None,
 731                 sequence=None,
 732                 script=share_data['coinbase'],
 733             )],
 734             tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT] + [dict(
 735                 value=0,
 736                 script='\x20' + cls.get_ref_hash(net, share_info, ref_merkle_link),
 737             )],
 738             lock_time=0,
 739         )
 740
 741         def get_share(header, transactions):
 742             min_header=dict(header);del min_header['merkle_root']
 743             return cls(net, None, dict(
 744                 min_header=min_header,
 745                 share_info=share_info,
 746                 ref_merkle_link=dict(branch=[], index=0),
 747                 hash_link=prefix_to_hash_link(bitcoin_data.tx_type.pack(gentx)[:-32-4], cls.gentx_before_refhash),
 748                 merkle_link=bitcoin_data.calculate_merkle_link([None] + other_transaction_hashes, 0),
 749             ))
 750
 751         return share_info, gentx, other_transaction_hashes, get_share
 752
 753     @classmethod
 754     def get_ref_hash(cls, net, share_info, ref_merkle_link):
 755         return pack.IntType(256).pack(bitcoin_data.check_merkle_link(bitcoin_data.hash256(cls.ref_type.pack(dict(
 756             identifier=net.IDENTIFIER,
 757             share_info=share_info,
 758         ))), ref_merkle_link))
 759
 760     __slots__ = 'net peer contents min_header share_info hash_link merkle_link hash share_data max_target target timestamp previous_hash new_script desired_version gentx_hash header pow_hash header_hash new_transaction_hashes time_seen'.split(' ')
 761
 762     def __init__(self, net, peer, contents):
 763         self.net = net
 764         self.peer = peer
 765         self.contents = contents
 766
 767         self.min_header = contents['min_header']
 768         self.share_info = contents['share_info']
 769         self.hash_link = contents['hash_link']
 770         self.merkle_link = contents['merkle_link']
 771
 772         if not (2 <= len(self.share_info['share_data']['coinbase']) <= 100):
 773             raise ValueError('''bad coinbase size! %i bytes''' % (len(self.share_info['share_data']['coinbase']),))
 774
 775         if len(self.merkle_link['branch']) > 16:
 776             raise ValueError('merkle branch too long!')
 777
 778         assert not self.hash_link['extra_data'], repr(self.hash_link['extra_data'])
 779
 780         self.share_data = self.share_info['share_data']
 781         self.max_target = self.share_info['max_bits'].target
 782         self.target = self.share_info['bits'].target
 783         self.timestamp = self.share_info['timestamp']
 784         self.previous_hash = self.share_data['previous_share_hash']
 785         self.new_script = bitcoin_data.pubkey_hash_to_script2(self.share_data['pubkey_hash'])
 786         self.desired_version = self.share_data['desired_version']
 787
 788         for x in self.share_info['transaction_hash_refs']:
 789             assert x['share_count'] < 110
 790         for i, x in enumerate(self.share_info['new_transaction_hashes']):
 791             assert dict(share_count=0, tx_count=i) in self.share_info['transaction_hash_refs']
 792
 793         self.gentx_hash = check_hash_link(
 794             self.hash_link,
 795             self.get_ref_hash(net, self.share_info, contents['ref_merkle_link']) + pack.IntType(32).pack(0),
 796             self.gentx_before_refhash,
 797         )
 798         merkle_root = bitcoin_data.check_merkle_link(self.gentx_hash, self.merkle_link)
 799         self.header = dict(self.min_header, merkle_root=merkle_root)
 800         self.pow_hash = net.PARENT.POW_FUNC(bitcoin_data.block_header_type.pack(self.header))
 801         self.hash = self.header_hash = bitcoin_data.hash256(bitcoin_data.block_header_type.pack(self.header))
 802
 803         if self.target > net.MAX_TARGET:
 804             from p2pool import p2p
 805             raise p2p.PeerMisbehavingError('share target invalid')
 806
 807         if self.pow_hash > self.target:
 808             from p2pool import p2p
 809             raise p2p.PeerMisbehavingError('share PoW invalid')
 810
 811         self.new_transaction_hashes = self.share_info['new_transaction_hashes']
 812
 813         # XXX eww
 814         self.time_seen = time.time()
 815
 816     def __repr__(self):
 817         return 'Share' + repr((self.net, self.peer, self.contents))
 818
 819     def as_share(self):
 820         return dict(type=self.VERSION, contents=self.share_type.pack(self.contents))
 821
 822     def check(self, tracker):
 823         from p2pool import p2p
 824         if self.share_data['previous_share_hash'] is not None:
 825             previous_share = tracker.items[self.share_data['previous_share_hash']]
 826             if type(self) is type(previous_share):
 827                 pass
 828             elif type(self) is type(previous_share).SUCCESSOR:
 829                 if tracker.get_height(previous_share.hash) < self.net.CHAIN_LENGTH:
 830                     from p2pool import p2p
 831                     raise p2p.PeerMisbehavingError('switch without enough history')
 832
 833                 # switch only valid if 85% of hashes in [self.net.CHAIN_LENGTH*9//10, self.net.CHAIN_LENGTH] for new version
 834                 counts = get_desired_version_counts(tracker,
 835                     tracker.get_nth_parent_hash(previous_share.hash, self.net.CHAIN_LENGTH*9//10), self.net.CHAIN_LENGTH//10)
 836                 if counts.get(self.VERSION, 0) < sum(counts.itervalues())*85//100:
 837                     raise p2p.PeerMisbehavingError('switch without enough hash power upgraded')
 838             else:
 839                 raise p2p.PeerMisbehavingError('''%s can't follow %s''' % (type(self).__name__, type(previous_share).__name__))
 840
 841         other_tx_hashes = [tracker.items[tracker.get_nth_parent_hash(self.hash, x['share_count'])].share_info['new_transaction_hashes'][x['tx_count']] for x in self.share_info['transaction_hash_refs']]
 842
 843         share_info, gentx, other_tx_hashes2, get_share = self.generate_transaction(tracker, self.share_info['share_data'], self.header['bits'].target, self.share_info['timestamp'], self.share_info['bits'].target, self.contents['ref_merkle_link'], other_tx_hashes, self.net)
 844         assert other_tx_hashes2 == other_tx_hashes
 845         if share_info != self.share_info:
 846             raise ValueError('share_info invalid')
 847         if bitcoin_data.hash256(bitcoin_data.tx_type.pack(gentx)) != self.gentx_hash:
 848             raise ValueError('''gentx doesn't match hash_link''')
 849
 850         if bitcoin_data.calculate_merkle_link([None] + other_tx_hashes, 0) != self.merkle_link:
 851             raise ValueError('merkle_link and other_tx_hashes do not match')
 852
 853         return gentx # only used by as_block
 854
 855     def get_other_tx_hashes(self, tracker):
 856         if tracker.get_height(self.hash) <= max(x['share_count'] for x in self.share_info['transaction_hash_refs']):
 857             return None
 858         return [tracker.items[tracker.get_nth_parent_hash(self.hash, x['share_count'])].share_info['new_transaction_hashes'][x['tx_count']] for x in self.share_info['transaction_hash_refs']]
 859
 860     def _get_other_txs(self, tracker, known_txs):
 861         other_tx_hashes = self.get_other_tx_hashes(tracker)
 862         if other_tx_hashes is None:
 863             return None # not all parents present
 864
 865         if not all(tx_hash in known_txs for tx_hash in other_tx_hashes):
 866             return None # not all txs present
 867
 868         return [known_txs[tx_hash] for tx_hash in other_tx_hashes]
 869
 870     def should_punish_reason(self, previous_block, bits, tracker, known_txs):
 871         if (self.header['previous_block'], self.header['bits']) != (previous_block, bits) and self.header_hash != previous_block and self.peer is not None:
 872             return True, 'Block-stale detected! %x < %x' % (self.header['previous_block'], previous_block)
 873
 874         if self.pow_hash <= self.header['bits'].target:
 875             return -1, 'block solution'
 876
 877         other_txs = self._get_other_txs(tracker, known_txs)
 878         if other_txs is None:
 879             return True, 'not all txs present'
 880         else:
 881             all_txs_size = sum(bitcoin_data.tx_type.packed_size(tx) for tx in other_txs)
 882             if all_txs_size > 1000000:
 883                 return True, 'txs over block size limit'
 884
 885             new_txs_size = sum(bitcoin_data.tx_type.packed_size(known_txs[tx_hash]) for tx_hash in self.share_info['new_transaction_hashes'])
 886             if new_txs_size > 50000:
 887                 return True, 'new txs over limit'
 888
 889         return False, None
 890
 891     def as_block(self, tracker, known_txs):
 892         other_txs = self._get_other_txs(tracker, known_txs)
 893         if other_txs is None:
 894             return None # not all txs present
 895         return dict(header=self.header, txs=[self.check(tracker)] + other_txs)
 896
 897
 898 class WeightsSkipList(forest.TrackerSkipList):
 899     # share_count, weights, total_weight
 900
 901     def get_delta(self, element):
 902         from p2pool.bitcoin import data as bitcoin_data
 903         share = self.tracker.items[element]
 904         att = bitcoin_data.target_to_average_attempts(share.target)
 905         return 1, {share.new_script: att*(65535-share.share_data['donation'])}, att*65535, att*share.share_data['donation']
 906
 907     def combine_deltas(self, (share_count1, weights1, total_weight1, total_donation_weight1), (share_count2, weights2, total_weight2, total_donation_weight2)):
 908         return share_count1 + share_count2, math.add_dicts(weights1, weights2), total_weight1 + total_weight2, total_donation_weight1 + total_donation_weight2
 909
 910     def initial_solution(self, start, (max_shares, desired_weight)):
 911         assert desired_weight % 65535 == 0, divmod(desired_weight, 65535)
 912         return 0, None, 0, 0
 913
 914     def apply_delta(self, (share_count1, weights_list, total_weight1, total_donation_weight1), (share_count2, weights2, total_weight2, total_donation_weight2), (max_shares, desired_weight)):
 915         if total_weight1 + total_weight2 > desired_weight and share_count2 == 1:
 916             assert (desired_weight - total_weight1) % 65535 == 0
 917             script, = weights2.iterkeys()
 918             new_weights = {script: (desired_weight - total_weight1)//65535*weights2[script]//(total_weight2//65535)}
 919             return share_count1 + share_count2, (weights_list, new_weights), desired_weight, total_donation_weight1 + (desired_weight - total_weight1)//65535*total_donation_weight2//(total_weight2//65535)
 920         return share_count1 + share_count2, (weights_list, weights2), total_weight1 + total_weight2, total_donation_weight1 + total_donation_weight2
 921
 922     def judge(self, (share_count, weights_list, total_weight, total_donation_weight), (max_shares, desired_weight)):
 923         if share_count > max_shares or total_weight > desired_weight:
 924             return 1
 925         elif share_count == max_shares or total_weight == desired_weight:
 926             return 0
 927         else:
 928             return -1
 929
 930     def finalize(self, (share_count, weights_list, total_weight, total_donation_weight), (max_shares, desired_weight)):
 931         assert share_count <= max_shares and total_weight <= desired_weight
 932         assert share_count == max_shares or total_weight == desired_weight
 933         return math.add_dicts(*math.flatten_linked_list(weights_list)), total_weight, total_donation_weight
 934
 935 class OkayTracker(forest.Tracker):
 936     def __init__(self, net):
 937         forest.Tracker.__init__(self, delta_type=forest.get_attributedelta_type(dict(forest.AttributeDelta.attrs,
 938             work=lambda share: bitcoin_data.target_to_average_attempts(share.target),
 939             min_work=lambda share: bitcoin_data.target_to_average_attempts(share.max_target),
 940         )))
 941         self.net = net
 942         self.verified = forest.SubsetTracker(delta_type=forest.get_attributedelta_type(dict(forest.AttributeDelta.attrs,
 943             work=lambda share: bitcoin_data.target_to_average_attempts(share.target),
 944         )), subset_of=self)
 945         self.get_cumulative_weights = WeightsSkipList(self)
 946
 947     def attempt_verify(self, share):
 948         if share.hash in self.verified.items:
 949             return True
 950         height, last = self.get_height_and_last(share.hash)
 951         if height < self.net.CHAIN_LENGTH + 1 and last is not None:
 952             raise AssertionError()
 953         try:
 954             share.check(self)
 955         except:
 956             log.err(None, 'Share check failed:')
 957             return False
 958         else:
 959             self.verified.add(share)
 960             return True
 961
 962     def think(self, block_rel_height_func, previous_block, bits, known_txs):
 963         desired = set()
 964
 965         # O(len(self.heads))
 966         #   make 'unverified heads' set?
 967         # for each overall head, attempt verification
 968         # if it fails, attempt on parent, and repeat
 969         # if no successful verification because of lack of parents, request parent
 970         bads = set()
 971         for head in set(self.heads) - set(self.verified.heads):
 972             head_height, last = self.get_height_and_last(head)
 973
 974             for share in self.get_chain(head, head_height if last is None else min(5, max(0, head_height - self.net.CHAIN_LENGTH))):
 975                 if self.attempt_verify(share):
 976                     break
 977                 if share.hash in self.heads:
 978                     bads.add(share.hash)
 979             else:
 980                 if last is not None:
 981                     desired.add((
 982                         self.items[random.choice(list(self.reverse[last]))].peer,
 983                         last,
 984                         max(x.timestamp for x in self.get_chain(head, min(head_height, 5))),
 985                         min(x.target for x in self.get_chain(head, min(head_height, 5))),
 986                     ))
 987         for bad in bads:
 988             assert bad not in self.verified.items
 989             assert bad in self.heads
 990             if p2pool.DEBUG:
 991                 print "BAD", bad
 992             self.remove(bad)
 993
 994         # try to get at least CHAIN_LENGTH height for each verified head, requesting parents if needed
 995         for head in list(self.verified.heads):
 996             head_height, last_hash = self.verified.get_height_and_last(head)
 997             last_height, last_last_hash = self.get_height_and_last(last_hash)
 998             # XXX review boundary conditions
 999             want = max(self.net.CHAIN_LENGTH - head_height, 0)
1000             can = max(last_height - 1 - self.net.CHAIN_LENGTH, 0) if last_last_hash is not None else last_height
1001             get = min(want, can)
1002             #print 'Z', head_height, last_hash is None, last_height, last_last_hash is None, want, can, get
1003             for share in self.get_chain(last_hash, get):
1004                 if not self.attempt_verify(share):
1005                     break
1006             if head_height < self.net.CHAIN_LENGTH and last_last_hash is not None:
1007                 desired.add((
1008                     self.items[random.choice(list(self.verified.reverse[last_hash]))].peer,
1009                     last_last_hash,
1010                     max(x.timestamp for x in self.get_chain(head, min(head_height, 5))),
1011                     min(x.target for x in self.get_chain(head, min(head_height, 5))),
1012                 ))
1013
1014         # decide best tree
1015         decorated_tails = sorted((self.score(max(self.verified.tails[tail_hash], key=self.verified.get_work), block_rel_height_func), tail_hash) for tail_hash in self.verified.tails)
1016         if p2pool.DEBUG:
1017             print len(decorated_tails), 'tails:'
1018             for score, tail_hash in decorated_tails:
1019                 print format_hash(tail_hash), score
1020         best_tail_score, best_tail = decorated_tails[-1] if decorated_tails else (None, None)
1021
1022         # decide best verified head
1023         decorated_heads = sorted(((
1024             self.verified.get_work(self.verified.get_nth_parent_hash(h, min(5, self.verified.get_height(h)))),
1025             #self.items[h].peer is None,
1026             -self.items[h].should_punish_reason(previous_block, bits, self, known_txs)[0],
1027             -self.items[h].time_seen,
1028         ), h) for h in self.verified.tails.get(best_tail, []))
1029         if p2pool.DEBUG:
1030             print len(decorated_heads), 'heads. Top 10:'
1031             for score, head_hash in decorated_heads[-10:]:
1032                 print '   ', format_hash(head_hash), format_hash(self.items[head_hash].previous_hash), score
1033         best_head_score, best = decorated_heads[-1] if decorated_heads else (None, None)
1034
1035         if best is not None:
1036             best_share = self.items[best]
1037             punish, punish_reason = best_share.should_punish_reason(previous_block, bits, self, known_txs)
1038             if punish > 0:
1039                 print 'Punishing share for %r! Jumping from %s to %s!' % (punish_reason, format_hash(best), format_hash(best_share.previous_hash))
1040                 best = best_share.previous_hash
1041
1042             timestamp_cutoff = min(int(time.time()), best_share.timestamp) - 3600
1043             target_cutoff = 2**256//(self.net.SHARE_PERIOD*best_tail_score[1] + 1) * 2 if best_tail_score[1] is not None else 2**256-1
1044         else:
1045             timestamp_cutoff = int(time.time()) - 24*60*60
1046             target_cutoff = 2**256-1
1047
1048         if p2pool.DEBUG:
1049             print 'Desire %i shares. Cutoff: %s old diff>%.2f' % (len(desired), math.format_dt(time.time() - timestamp_cutoff), bitcoin_data.target_to_difficulty(target_cutoff))
1050             for peer, hash, ts, targ in desired:
1051                 print '   ', '%s:%i' % peer.addr if peer is not None else None, format_hash(hash), math.format_dt(time.time() - ts), bitcoin_data.target_to_difficulty(targ), ts >= timestamp_cutoff, targ <= target_cutoff
1052
1053         return best, [(peer, hash) for peer, hash, ts, targ in desired if ts >= timestamp_cutoff], decorated_heads
1054
1055     def score(self, share_hash, block_rel_height_func):
1056         # returns approximate lower bound on chain's hashrate in the last self.net.CHAIN_LENGTH*15//16*self.net.SHARE_PERIOD time
1057
1058         head_height = self.verified.get_height(share_hash)
1059         if head_height < self.net.CHAIN_LENGTH:
1060             return head_height, None
1061
1062         end_point = self.verified.get_nth_parent_hash(share_hash, self.net.CHAIN_LENGTH*15//16)
1063
1064         block_height = max(block_rel_height_func(share.header['previous_block']) for share in
1065             self.verified.get_chain(end_point, self.net.CHAIN_LENGTH//16))
1066
1067         return self.net.CHAIN_LENGTH, self.verified.get_delta(share_hash, end_point).work//((0 - block_height + 1)*self.net.PARENT.BLOCK_PERIOD)
1068
1069 def get_pool_attempts_per_second(tracker, previous_share_hash, dist, min_work=False, integer=False):
1070     assert dist >= 2
1071     near = tracker.items[previous_share_hash]
1072     far = tracker.items[tracker.get_nth_parent_hash(previous_share_hash, dist - 1)]
1073     attempts = tracker.get_delta(near.hash, far.hash).work if not min_work else tracker.get_delta(near.hash, far.hash).min_work
1074     time = near.timestamp - far.timestamp
1075     if time <= 0:
1076         time = 1
1077     if integer:
1078         return attempts//time
1079     return attempts/time
1080
1081 def get_average_stale_prop(tracker, share_hash, lookbehind):
1082     stales = sum(1 for share in tracker.get_chain(share_hash, lookbehind) if share.share_data['stale_info'] is not None)
1083     return stales/(lookbehind + stales)
1084
1085 def get_stale_counts(tracker, share_hash, lookbehind, rates=False):
1086     res = {}
1087     for share in tracker.get_chain(share_hash, lookbehind - 1):
1088         res['good'] = res.get('good', 0) + bitcoin_data.target_to_average_attempts(share.target)
1089         s = share.share_data['stale_info']
1090         if s is not None:
1091             res[s] = res.get(s, 0) + bitcoin_data.target_to_average_attempts(share.target)
1092     if rates:
1093         dt = tracker.items[share_hash].timestamp - tracker.items[tracker.get_nth_parent_hash(share_hash, lookbehind - 1)].timestamp
1094         res = dict((k, v/dt) for k, v in res.iteritems())
1095     return res
1096
1097 def get_user_stale_props(tracker, share_hash, lookbehind):
1098     res = {}
1099     for share in tracker.get_chain(share_hash, lookbehind - 1):
1100         stale, total = res.get(share.share_data['pubkey_hash'], (0, 0))
1101         total += 1
1102         if share.share_data['stale_info'] is not None:
1103             stale += 1
1104             total += 1
1105         res[share.share_data['pubkey_hash']] = stale, total
1106     return dict((pubkey_hash, stale/total) for pubkey_hash, (stale, total) in res.iteritems())
1107
1108 def get_expected_payouts(tracker, best_share_hash, block_target, subsidy, net):
1109     weights, total_weight, donation_weight = tracker.get_cumulative_weights(best_share_hash, min(tracker.get_height(best_share_hash), net.REAL_CHAIN_LENGTH), 65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target))
1110     res = dict((script, subsidy*weight//total_weight) for script, weight in weights.iteritems())
1111     res[DONATION_SCRIPT] = res.get(DONATION_SCRIPT, 0) + subsidy - sum(res.itervalues())
1112     return res
1113
1114 def get_desired_version_counts(tracker, best_share_hash, dist):
1115     res = {}
1116     for share in tracker.get_chain(best_share_hash, dist):
1117         res[share.desired_version] = res.get(share.desired_version, 0) + bitcoin_data.target_to_average_attempts(share.target)
1118     return res
1119
1120 def get_warnings(tracker, best_share, net, bitcoind_warning, bitcoind_work_value):
1121     res = []
1122
1123     desired_version_counts = get_desired_version_counts(tracker, best_share,
1124         min(net.CHAIN_LENGTH, 60*60//net.SHARE_PERIOD, tracker.get_height(best_share)))
1125     majority_desired_version = max(desired_version_counts, key=lambda k: desired_version_counts[k])
1126     if majority_desired_version > NewNewShare.VERSION and desired_version_counts[majority_desired_version] > sum(desired_version_counts.itervalues())/2:
1127         res.append('A MAJORITY OF SHARES CONTAIN A VOTE FOR AN UNSUPPORTED SHARE IMPLEMENTATION! (v%i with %i%% support)\n'
1128             'An upgrade is likely necessary. Check http://p2pool.forre.st/ for more information.' % (
1129                 majority_desired_version, 100*desired_version_counts[majority_desired_version]/sum(desired_version_counts.itervalues())))
1130
1131     if bitcoind_warning is not None:
1132         if 'This is a pre-release test build' not in bitcoind_warning:
1133             res.append('(from bitcoind) %s' % (bitcoind_warning,))
1134
1135     if time.time() > bitcoind_work_value['last_update'] + 60:
1136         res.append('''LOST CONTACT WITH BITCOIND for %s! Check that it isn't frozen or dead!''' % (math.format_dt(time.time() - bitcoind_work_value['last_update']),))
1137
1138     return res
1139
1140 def format_hash(x):
1141     if x is None:
1142         return 'xxxxxxxx'
1143     return '%08x' % (x % 2**32)
1144
1145 class ShareStore(object):
1146     def __init__(self, prefix, net):
1147         self.filename = prefix
1148         self.dirname = os.path.dirname(os.path.abspath(prefix))
1149         self.filename = os.path.basename(os.path.abspath(prefix))
1150         self.net = net
1151         self.known = None # will be filename -> set of share hashes, set of verified hashes
1152         self.known_desired = None
1153
1154     def get_shares(self):
1155         if self.known is not None:
1156             raise AssertionError()
1157         known = {}
1158         filenames, next = self.get_filenames_and_next()
1159         for filename in filenames:
1160             share_hashes, verified_hashes = known.setdefault(filename, (set(), set()))
1161             with open(filename, 'rb') as f:
1162                 for line in f:
1163                     try:
1164                         type_id_str, data_hex = line.strip().split(' ')
1165                         type_id = int(type_id_str)
1166                         if type_id == 0:
1167                             pass
1168                         elif type_id == 1:
1169                             pass
1170                         elif type_id == 2:
1171                             verified_hash = int(data_hex, 16)
1172                             yield 'verified_hash', verified_hash
1173                             verified_hashes.add(verified_hash)
1174                         elif type_id == 5:
1175                             raw_share = share_type.unpack(data_hex.decode('hex'))
1176                             if raw_share['type'] in [0, 1, 2, 3, 6, 7]:
1177                                 continue
1178                             share = load_share(raw_share, self.net, None)
1179                             yield 'share', share
1180                             share_hashes.add(share.hash)
1181                         else:
1182                             raise NotImplementedError("share type %i" % (type_id,))
1183                     except Exception:
1184                         log.err(None, "HARMLESS error while reading saved shares, continuing where left off:")
1185         self.known = known
1186         self.known_desired = dict((k, (set(a), set(b))) for k, (a, b) in known.iteritems())
1187
1188     def _add_line(self, line):
1189         filenames, next = self.get_filenames_and_next()
1190         if filenames and os.path.getsize(filenames[-1]) < 10e6:
1191             filename = filenames[-1]
1192         else:
1193             filename = next
1194
1195         with open(filename, 'ab') as f:
1196             f.write(line + '\n')
1197
1198         return filename
1199
1200     def add_share(self, share):
1201         for filename, (share_hashes, verified_hashes) in self.known.iteritems():
1202             if share.hash in share_hashes:
1203                 break
1204         else:
1205             filename = self._add_line("%i %s" % (5, share_type.pack(share.as_share()).encode('hex')))
1206             share_hashes, verified_hashes = self.known.setdefault(filename, (set(), set()))
1207             share_hashes.add(share.hash)
1208         share_hashes, verified_hashes = self.known_desired.setdefault(filename, (set(), set()))
1209         share_hashes.add(share.hash)
1210
1211     def add_verified_hash(self, share_hash):
1212         for filename, (share_hashes, verified_hashes) in self.known.iteritems():
1213             if share_hash in verified_hashes:
1214                 break
1215         else:
1216             filename = self._add_line("%i %x" % (2, share_hash))
1217             share_hashes, verified_hashes = self.known.setdefault(filename, (set(), set()))
1218             verified_hashes.add(share_hash)
1219         share_hashes, verified_hashes = self.known_desired.setdefault(filename, (set(), set()))
1220         verified_hashes.add(share_hash)
1221
1222     def get_filenames_and_next(self):
1223         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())
1224         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)))
1225
1226     def forget_share(self, share_hash):
1227         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
1228             if share_hash in share_hashes:
1229                 share_hashes.remove(share_hash)
1230         self.check_remove()
1231
1232     def forget_verified_share(self, share_hash):
1233         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
1234             if share_hash in verified_hashes:
1235                 verified_hashes.remove(share_hash)
1236         self.check_remove()
1237
1238     def check_remove(self):
1239         to_remove = set()
1240         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
1241             #print filename, len(share_hashes) + len(verified_hashes)
1242             if not share_hashes and not verified_hashes:
1243                 to_remove.add(filename)
1244         for filename in to_remove:
1245             self.known.pop(filename)
1246             self.known_desired.pop(filename)
1247             os.remove(filename)
1248             print "REMOVED", filename