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     else:
  54         raise ValueError('unknown share type: %r' % (share['type'],))
  55
  56 DONATION_SCRIPT = '4104ffd03de44a6e11b9917f3a29f9443283d9871c9d743ef30d5eddcd37094b64d1b3d8090496b53256786bf5c82932ec23c3b74d9f05a6f95a8b5529352656664bac'.decode('hex')
  57
  58 class Share(object):
  59     VERSION = 7
  60     SUCCESSOR = None
  61
  62     small_block_header_type = pack.ComposedType([
  63         ('version', pack.VarIntType()), # XXX must be constrained to 32 bits
  64         ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))),
  65         ('timestamp', pack.IntType(32)),
  66         ('bits', bitcoin_data.FloatingIntegerType()),
  67         ('nonce', pack.IntType(32)),
  68     ])
  69
  70     share_data_type = pack.ComposedType([
  71         ('previous_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
  72         ('coinbase', pack.VarStrType()),
  73         ('nonce', pack.IntType(32)),
  74         ('pubkey_hash', pack.IntType(160)),
  75         ('subsidy', pack.IntType(64)),
  76         ('donation', pack.IntType(16)),
  77         ('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)))),
  78         ('desired_version', pack.VarIntType()),
  79     ])
  80
  81     share_info_type = pack.ComposedType([
  82         ('share_data', share_data_type),
  83         ('far_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
  84         ('max_bits', bitcoin_data.FloatingIntegerType()),
  85         ('bits', bitcoin_data.FloatingIntegerType()),
  86         ('timestamp', pack.IntType(32)),
  87     ])
  88
  89     share_common_type = pack.ComposedType([
  90         ('min_header', small_block_header_type),
  91         ('share_info', share_info_type),
  92         ('ref_merkle_link', pack.ComposedType([
  93             ('branch', pack.ListType(pack.IntType(256))),
  94             ('index', pack.VarIntType()),
  95         ])),
  96         ('hash_link', hash_link_type),
  97     ])
  98     share1a_type = pack.ComposedType([
  99         ('common', share_common_type),
 100         ('merkle_link', pack.ComposedType([
 101             ('branch', pack.ListType(pack.IntType(256))),
 102             ('index', pack.IntType(0)), # it will always be 0
 103         ])),
 104     ])
 105     share1b_type = pack.ComposedType([
 106         ('common', share_common_type),
 107         ('other_txs', pack.ListType(bitcoin_data.tx_type)),
 108     ])
 109
 110     ref_type = pack.ComposedType([
 111         ('identifier', pack.FixedStrType(64//8)),
 112         ('share_info', share_info_type),
 113     ])
 114
 115     gentx_before_refhash = pack.VarStrType().pack(DONATION_SCRIPT) + pack.IntType(64).pack(0) + pack.VarStrType().pack('\x20' + pack.IntType(256).pack(0))[:2]
 116
 117     @classmethod
 118     def generate_transaction(cls, tracker, share_data, block_target, desired_timestamp, desired_target, ref_merkle_link, desired_other_transaction_hashes, net, known_txs=None):
 119         previous_share = tracker.items[share_data['previous_share_hash']] if share_data['previous_share_hash'] is not None else None
 120
 121         height, last = tracker.get_height_and_last(share_data['previous_share_hash'])
 122         assert height >= net.REAL_CHAIN_LENGTH or last is None
 123         if height < net.TARGET_LOOKBEHIND:
 124             pre_target3 = net.MAX_TARGET
 125         else:
 126             attempts_per_second = get_pool_attempts_per_second(tracker, share_data['previous_share_hash'], net.TARGET_LOOKBEHIND, min_work=True, integer=True)
 127             pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1 if attempts_per_second else 2**256-1
 128             pre_target2 = math.clip(pre_target, (previous_share.max_target*9//10, previous_share.max_target*11//10))
 129             pre_target3 = math.clip(pre_target2, (net.MIN_TARGET, net.MAX_TARGET))
 130         max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
 131         bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//10, pre_target3)))
 132
 133         weights, total_weight, donation_weight = tracker.get_cumulative_weights(share_data['previous_share_hash'],
 134             min(height, net.REAL_CHAIN_LENGTH),
 135             65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target),
 136         )
 137         assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
 138
 139         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
 140         this_script = bitcoin_data.pubkey_hash_to_script2(share_data['pubkey_hash'])
 141         amounts[this_script] = amounts.get(this_script, 0) + share_data['subsidy']//200 # 0.5% goes to block finder
 142         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
 143
 144         if sum(amounts.itervalues()) != share_data['subsidy'] or any(x < 0 for x in amounts.itervalues()):
 145             raise ValueError()
 146
 147         dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit
 148
 149         share_info = dict(
 150             share_data=share_data,
 151             far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
 152             max_bits=max_bits,
 153             bits=bits,
 154             timestamp=math.clip(desired_timestamp, (
 155                 (previous_share.timestamp + net.SHARE_PERIOD) - (net.SHARE_PERIOD - 1), # = previous_share.timestamp + 1
 156                 (previous_share.timestamp + net.SHARE_PERIOD) + (net.SHARE_PERIOD - 1),
 157             )) if previous_share is not None else desired_timestamp,
 158         )
 159
 160         gentx = dict(
 161             version=1,
 162             tx_ins=[dict(
 163                 previous_output=None,
 164                 sequence=None,
 165                 script=share_data['coinbase'].ljust(2, '\x00'),
 166             )],
 167             tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT] + [dict(
 168                 value=0,
 169                 script='\x20' + cls.get_ref_hash(net, share_info, ref_merkle_link),
 170             )],
 171             lock_time=0,
 172         )
 173
 174         def get_share(header, transactions):
 175             assert transactions[0] == gentx and [bitcoin_data.hash256(bitcoin_data.tx_type.pack(tx)) for tx in transactions[1:]] == desired_other_transaction_hashes
 176             min_header = dict(header);del min_header['merkle_root']
 177             hash_link = prefix_to_hash_link(bitcoin_data.tx_type.pack(gentx)[:-32-4], cls.gentx_before_refhash)
 178             merkle_link = bitcoin_data.calculate_merkle_link([None] + desired_other_transaction_hashes, 0)
 179             pow_hash = net.PARENT.POW_FUNC(bitcoin_data.block_header_type.pack(header))
 180             return cls(net, None, dict(
 181                 min_header=min_header, share_info=share_info, hash_link=hash_link,
 182                 ref_merkle_link=dict(branch=[], index=0),
 183             ), merkle_link=merkle_link, other_txs=transactions[1:] if pow_hash <= header['bits'].target else None)
 184
 185         return share_info, gentx, desired_other_transaction_hashes, get_share
 186
 187     @classmethod
 188     def get_ref_hash(cls, net, share_info, ref_merkle_link):
 189         return pack.IntType(256).pack(bitcoin_data.check_merkle_link(bitcoin_data.hash256(cls.ref_type.pack(dict(
 190             identifier=net.IDENTIFIER,
 191             share_info=share_info,
 192         ))), ref_merkle_link))
 193
 194     __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(' ')
 195
 196     def __init__(self, net, peer, common, merkle_link, other_txs):
 197         self.net = net
 198         self.peer = peer
 199         self.common = common
 200         self.min_header = common['min_header']
 201         self.share_info = common['share_info']
 202         self.hash_link = common['hash_link']
 203         self.merkle_link = merkle_link
 204         self.other_txs = other_txs
 205
 206         if len(self.share_info['share_data']['coinbase']) > 100:
 207             raise ValueError('''coinbase too large! %i bytes''' % (len(self.share_info['share_data']['coinbase']),))
 208
 209         if len(merkle_link['branch']) > 16:
 210             raise ValueError('merkle branch too long!')
 211
 212         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:
 213             raise ValueError('merkle_link and other_txs do not match')
 214
 215         assert not self.hash_link['extra_data'], repr(self.hash_link['extra_data'])
 216
 217         self.share_data = self.share_info['share_data']
 218         self.max_target = self.share_info['max_bits'].target
 219         self.target = self.share_info['bits'].target
 220         self.timestamp = self.share_info['timestamp']
 221         self.previous_hash = self.share_data['previous_share_hash']
 222         self.new_script = bitcoin_data.pubkey_hash_to_script2(self.share_data['pubkey_hash'])
 223         self.desired_version = self.share_data['desired_version']
 224
 225         self.gentx_hash = check_hash_link(
 226             self.hash_link,
 227             self.get_ref_hash(net, self.share_info, common['ref_merkle_link']) + pack.IntType(32).pack(0),
 228             self.gentx_before_refhash,
 229         )
 230         merkle_root = bitcoin_data.check_merkle_link(self.gentx_hash, merkle_link)
 231         self.header = dict(self.min_header, merkle_root=merkle_root)
 232         self.pow_hash = net.PARENT.POW_FUNC(bitcoin_data.block_header_type.pack(self.header))
 233         self.hash = self.header_hash = bitcoin_data.hash256(bitcoin_data.block_header_type.pack(self.header))
 234
 235         if self.pow_hash > self.target:
 236             from p2pool import p2p
 237             raise p2p.PeerMisbehavingError('share PoW invalid')
 238
 239         if other_txs is not None and not self.pow_hash <= self.header['bits'].target:
 240             raise ValueError('other_txs provided when not a block solution')
 241         if other_txs is None and self.pow_hash <= self.header['bits'].target:
 242             raise ValueError('other_txs not provided when a block solution')
 243
 244         self.new_transaction_hashes = []
 245
 246         # XXX eww
 247         self.time_seen = time.time()
 248
 249     def __repr__(self):
 250         return '<Share %s>' % (' '.join('%s=%r' % (k, getattr(self, k)) for k in self.__slots__),)
 251
 252     def as_share1a(self):
 253         return dict(type=4, contents=self.share1a_type.pack(dict(common=self.common, merkle_link=self.merkle_link)))
 254
 255     def as_share1b(self):
 256         return dict(type=5, contents=self.share1b_type.pack(dict(common=self.common, other_txs=self.other_txs)))
 257
 258     def as_share(self):
 259         if not self.pow_hash <= self.header['bits'].target: # share1a
 260             return self.as_share1a()
 261         else:
 262             return self.as_share1b()
 263
 264     def check(self, tracker):
 265         from p2pool import p2p
 266         if self.share_data['previous_share_hash'] is not None:
 267             previous_share = tracker.items[self.share_data['previous_share_hash']]
 268             if type(self) is type(previous_share):
 269                 pass
 270             elif type(self) is type(previous_share).SUCCESSOR:
 271                 if tracker.get_height(previous_share.hash) < self.net.CHAIN_LENGTH:
 272                     from p2pool import p2p
 273                     raise p2p.PeerMisbehavingError('switch without enough history')
 274
 275                 # switch only valid if 85% of hashes in [self.net.CHAIN_LENGTH*9//10, self.net.CHAIN_LENGTH] for new version
 276                 counts = get_desired_version_counts(tracker,
 277                     tracker.get_nth_parent_hash(previous_share.hash, self.net.CHAIN_LENGTH*9//10), self.net.CHAIN_LENGTH//10)
 278                 if counts.get(self.VERSION, 0) < sum(counts.itervalues())*85//100:
 279                     raise p2p.PeerMisbehavingError('switch without enough hash power upgraded')
 280             else:
 281                 raise p2p.PeerMisbehavingError('''%s can't follow %s''' % (type(self).__name__, type(previous_share).__name__))
 282
 283         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
 284         if share_info != self.share_info:
 285             raise ValueError('share_info invalid')
 286         if bitcoin_data.hash256(bitcoin_data.tx_type.pack(gentx)) != self.gentx_hash:
 287             raise ValueError('''gentx doesn't match hash_link''')
 288         return gentx # only used by as_block
 289
 290     def get_other_tx_hashes(self, tracker):
 291         return []
 292
 293     def should_punish_reason(self, previous_block, bits, tracker, known_txs):
 294         if (self.header['previous_block'], self.header['bits']) != (previous_block, bits) and self.header_hash != previous_block and self.peer is not None:
 295             return True, 'Block-stale detected! %x < %x' % (self.header['previous_block'], previous_block)
 296
 297         if self.pow_hash <= self.header['bits'].target:
 298             return -1, 'block solution'
 299
 300         return False, None
 301
 302     def as_block(self, tracker, known_txs):
 303         if self.other_txs is None:
 304             raise ValueError('share does not contain all txs')
 305         return dict(header=self.header, txs=[self.check(tracker)] + self.other_txs)
 306
 307 class NewShare(object):
 308     VERSION = 8
 309     SUCCESSOR = None
 310
 311     other_txs = None
 312
 313     small_block_header_type = pack.ComposedType([
 314         ('version', pack.VarIntType()),
 315         ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))),
 316         ('timestamp', pack.IntType(32)),
 317         ('bits', bitcoin_data.FloatingIntegerType()),
 318         ('nonce', pack.IntType(32)),
 319     ])
 320
 321     share_info_type = pack.ComposedType([
 322         ('share_data', pack.ComposedType([
 323             ('previous_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
 324             ('coinbase', pack.VarStrType()),
 325             ('nonce', pack.IntType(32)),
 326             ('pubkey_hash', pack.IntType(160)),
 327             ('subsidy', pack.IntType(64)),
 328             ('donation', pack.IntType(16)),
 329             ('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)))),
 330             ('desired_version', pack.VarIntType()),
 331         ])),
 332         ('new_transaction_hashes', pack.ListType(pack.IntType(256))),
 333         ('transaction_hash_refs', pack.ListType(pack.ComposedType([ # compressed by referencing previous shares' hashes
 334             ('share_count', pack.VarIntType()),
 335             ('tx_count', pack.VarIntType()),
 336         ]))),
 337         ('far_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
 338         ('max_bits', bitcoin_data.FloatingIntegerType()),
 339         ('bits', bitcoin_data.FloatingIntegerType()),
 340         ('timestamp', pack.IntType(32)),
 341     ])
 342
 343     share_type = pack.ComposedType([
 344         ('min_header', small_block_header_type),
 345         ('share_info', share_info_type),
 346         ('ref_merkle_link', pack.ComposedType([
 347             ('branch', pack.ListType(pack.IntType(256))),
 348             ('index', pack.IntType(0)),
 349         ])),
 350         ('hash_link', hash_link_type),
 351         ('merkle_link', pack.ComposedType([
 352             ('branch', pack.ListType(pack.IntType(256))),
 353             ('index', pack.IntType(0)), # it will always be 0
 354         ])),
 355     ])
 356
 357     ref_type = pack.ComposedType([
 358         ('identifier', pack.FixedStrType(64//8)),
 359         ('share_info', share_info_type),
 360     ])
 361
 362     gentx_before_refhash = pack.VarStrType().pack(DONATION_SCRIPT) + pack.IntType(64).pack(0) + pack.VarStrType().pack('\x20' + pack.IntType(256).pack(0))[:2]
 363
 364     @classmethod
 365     def generate_transaction(cls, tracker, share_data, block_target, desired_timestamp, desired_target, ref_merkle_link, desired_other_transaction_hashes, net, known_txs=None):
 366         previous_share = tracker.items[share_data['previous_share_hash']] if share_data['previous_share_hash'] is not None else None
 367
 368         height, last = tracker.get_height_and_last(share_data['previous_share_hash'])
 369         assert height >= net.REAL_CHAIN_LENGTH or last is None
 370         if height < net.TARGET_LOOKBEHIND:
 371             pre_target3 = net.MAX_TARGET
 372         else:
 373             attempts_per_second = get_pool_attempts_per_second(tracker, share_data['previous_share_hash'], net.TARGET_LOOKBEHIND, min_work=True, integer=True)
 374             pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1 if attempts_per_second else 2**256-1
 375             pre_target2 = math.clip(pre_target, (previous_share.max_target*9//10, previous_share.max_target*11//10))
 376             pre_target3 = math.clip(pre_target2, (net.MIN_TARGET, net.MAX_TARGET))
 377         max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
 378         bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//10, pre_target3)))
 379
 380         weights, total_weight, donation_weight = tracker.get_cumulative_weights(share_data['previous_share_hash'],
 381             min(height, net.REAL_CHAIN_LENGTH),
 382             65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target),
 383         )
 384         assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
 385
 386         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
 387         this_script = bitcoin_data.pubkey_hash_to_script2(share_data['pubkey_hash'])
 388         amounts[this_script] = amounts.get(this_script, 0) + share_data['subsidy']//200 # 0.5% goes to block finder
 389         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
 390
 391         if sum(amounts.itervalues()) != share_data['subsidy'] or any(x < 0 for x in amounts.itervalues()):
 392             raise ValueError()
 393
 394         dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit
 395
 396         new_transaction_hashes = []
 397         new_transaction_size = 0
 398         transaction_hash_refs = []
 399         other_transaction_hashes = []
 400
 401         for tx_hash in desired_other_transaction_hashes:
 402             for i, share in enumerate(tracker.get_chain(share_data['previous_share_hash'], min(height, 100))):
 403                 if tx_hash in share.new_transaction_hashes:
 404                     this = dict(share_count=i+1, tx_count=share.new_transaction_hashes.index(tx_hash))
 405                     break
 406             else:
 407                 if known_txs is not None:
 408                     this_size = bitcoin_data.tx_type.packed_size(known_txs[tx_hash])
 409                     if new_transaction_size + this_size > 50000: # only allow 50 kB of new txns/share
 410                         break
 411                     new_transaction_size += this_size
 412                 new_transaction_hashes.append(tx_hash)
 413                 this = dict(share_count=0, tx_count=len(new_transaction_hashes)-1)
 414             transaction_hash_refs.append(this)
 415             other_transaction_hashes.append(tx_hash)
 416
 417         share_info = dict(
 418             share_data=share_data,
 419             far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
 420             max_bits=max_bits,
 421             bits=bits,
 422             timestamp=math.clip(desired_timestamp, (
 423                 (previous_share.timestamp + net.SHARE_PERIOD) - (net.SHARE_PERIOD - 1), # = previous_share.timestamp + 1
 424                 (previous_share.timestamp + net.SHARE_PERIOD) + (net.SHARE_PERIOD - 1),
 425             )) if previous_share is not None else desired_timestamp,
 426             new_transaction_hashes=new_transaction_hashes,
 427             transaction_hash_refs=transaction_hash_refs,
 428         )
 429
 430         gentx = dict(
 431             version=1,
 432             tx_ins=[dict(
 433                 previous_output=None,
 434                 sequence=None,
 435                 script=share_data['coinbase'],
 436             )],
 437             tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT] + [dict(
 438                 value=0,
 439                 script='\x20' + cls.get_ref_hash(net, share_info, ref_merkle_link),
 440             )],
 441             lock_time=0,
 442         )
 443
 444         def get_share(header, transactions):
 445             min_header=dict(header);del min_header['merkle_root']
 446             return cls(net, None, dict(
 447                 min_header=min_header,
 448                 share_info=share_info,
 449                 ref_merkle_link=dict(branch=[], index=0),
 450                 hash_link=prefix_to_hash_link(bitcoin_data.tx_type.pack(gentx)[:-32-4], cls.gentx_before_refhash),
 451                 merkle_link=bitcoin_data.calculate_merkle_link([None] + other_transaction_hashes, 0),
 452             ))
 453
 454         return share_info, gentx, other_transaction_hashes, get_share
 455
 456     @classmethod
 457     def get_ref_hash(cls, net, share_info, ref_merkle_link):
 458         return pack.IntType(256).pack(bitcoin_data.check_merkle_link(bitcoin_data.hash256(cls.ref_type.pack(dict(
 459             identifier=net.IDENTIFIER,
 460             share_info=share_info,
 461         ))), ref_merkle_link))
 462
 463     __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(' ')
 464
 465     def __init__(self, net, peer, contents):
 466         self.net = net
 467         self.peer = peer
 468         self.contents = contents
 469
 470         self.min_header = contents['min_header']
 471         self.share_info = contents['share_info']
 472         self.hash_link = contents['hash_link']
 473         self.merkle_link = contents['merkle_link']
 474
 475         if not (2 <= len(self.share_info['share_data']['coinbase']) <= 100):
 476             raise ValueError('''bad coinbase size! %i bytes''' % (len(self.share_info['share_data']['coinbase']),))
 477
 478         if len(self.merkle_link['branch']) > 16:
 479             raise ValueError('merkle branch too long!')
 480
 481         assert not self.hash_link['extra_data'], repr(self.hash_link['extra_data'])
 482
 483         self.share_data = self.share_info['share_data']
 484         self.max_target = self.share_info['max_bits'].target
 485         self.target = self.share_info['bits'].target
 486         self.timestamp = self.share_info['timestamp']
 487         self.previous_hash = self.share_data['previous_share_hash']
 488         self.new_script = bitcoin_data.pubkey_hash_to_script2(self.share_data['pubkey_hash'])
 489         self.desired_version = self.share_data['desired_version']
 490
 491         for x in self.share_info['transaction_hash_refs']:
 492             assert x['share_count'] < 110
 493         for i, x in enumerate(self.share_info['new_transaction_hashes']):
 494             assert dict(share_count=0, tx_count=i) in self.share_info['transaction_hash_refs']
 495
 496         self.gentx_hash = check_hash_link(
 497             self.hash_link,
 498             self.get_ref_hash(net, self.share_info, contents['ref_merkle_link']) + pack.IntType(32).pack(0),
 499             self.gentx_before_refhash,
 500         )
 501         merkle_root = bitcoin_data.check_merkle_link(self.gentx_hash, self.merkle_link)
 502         self.header = dict(self.min_header, merkle_root=merkle_root)
 503         self.pow_hash = net.PARENT.POW_FUNC(bitcoin_data.block_header_type.pack(self.header))
 504         self.hash = self.header_hash = bitcoin_data.hash256(bitcoin_data.block_header_type.pack(self.header))
 505
 506         if self.target > net.MAX_TARGET:
 507             from p2pool import p2p
 508             raise p2p.PeerMisbehavingError('share target invalid')
 509
 510         if self.pow_hash > self.target:
 511             from p2pool import p2p
 512             raise p2p.PeerMisbehavingError('share PoW invalid')
 513
 514         self.new_transaction_hashes = self.share_info['new_transaction_hashes']
 515
 516         # XXX eww
 517         self.time_seen = time.time()
 518
 519     def __repr__(self):
 520         return 'Share' + repr((self.net, self.peer, self.contents))
 521
 522     def as_share(self):
 523         return dict(type=self.VERSION, contents=self.share_type.pack(self.contents))
 524
 525     def check(self, tracker):
 526         from p2pool import p2p
 527         if self.share_data['previous_share_hash'] is not None:
 528             previous_share = tracker.items[self.share_data['previous_share_hash']]
 529             if type(self) is type(previous_share):
 530                 pass
 531             elif type(self) is type(previous_share).SUCCESSOR:
 532                 if tracker.get_height(previous_share.hash) < self.net.CHAIN_LENGTH:
 533                     from p2pool import p2p
 534                     raise p2p.PeerMisbehavingError('switch without enough history')
 535
 536                 # switch only valid if 85% of hashes in [self.net.CHAIN_LENGTH*9//10, self.net.CHAIN_LENGTH] for new version
 537                 counts = get_desired_version_counts(tracker,
 538                     tracker.get_nth_parent_hash(previous_share.hash, self.net.CHAIN_LENGTH*9//10), self.net.CHAIN_LENGTH//10)
 539                 if counts.get(self.VERSION, 0) < sum(counts.itervalues())*85//100:
 540                     raise p2p.PeerMisbehavingError('switch without enough hash power upgraded')
 541             else:
 542                 raise p2p.PeerMisbehavingError('''%s can't follow %s''' % (type(self).__name__, type(previous_share).__name__))
 543
 544         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']]
 545
 546         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)
 547         assert other_tx_hashes2 == other_tx_hashes
 548         if share_info != self.share_info:
 549             raise ValueError('share_info invalid')
 550         if bitcoin_data.hash256(bitcoin_data.tx_type.pack(gentx)) != self.gentx_hash:
 551             raise ValueError('''gentx doesn't match hash_link''')
 552
 553         if bitcoin_data.calculate_merkle_link([None] + other_tx_hashes, 0) != self.merkle_link:
 554             raise ValueError('merkle_link and other_tx_hashes do not match')
 555
 556         return gentx # only used by as_block
 557
 558     def get_other_tx_hashes(self, tracker):
 559         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']]
 560
 561     def _get_other_txs(self, tracker, known_txs):
 562         other_tx_hashes = self.get_other_tx_hashes(tracker)
 563
 564         if not all(tx_hash in known_txs for tx_hash in other_tx_hashes):
 565             return None # not all txs present
 566
 567         return [known_txs[tx_hash] for tx_hash in other_tx_hashes]
 568
 569     def should_punish_reason(self, previous_block, bits, tracker, known_txs):
 570         if (self.header['previous_block'], self.header['bits']) != (previous_block, bits) and self.header_hash != previous_block and self.peer is not None:
 571             return True, 'Block-stale detected! %x < %x' % (self.header['previous_block'], previous_block)
 572
 573         if self.pow_hash <= self.header['bits'].target:
 574             return -1, 'block solution'
 575
 576         other_txs = self._get_other_txs(tracker, known_txs)
 577         if other_txs is None:
 578             return True, 'not all txs present'
 579         else:
 580             all_txs_size = sum(bitcoin_data.tx_type.packed_size(tx) for tx in other_txs)
 581             if all_txs_size > 1000000:
 582                 return True, 'txs over block size limit'
 583
 584             new_txs_size = sum(bitcoin_data.tx_type.packed_size(known_txs[tx_hash]) for tx_hash in self.share_info['new_transaction_hashes'])
 585             if new_txs_size > 50000:
 586                 return True, 'new txs over limit'
 587
 588         return False, None
 589
 590     def as_block(self, tracker, known_txs):
 591         other_txs = self._get_other_txs(tracker, known_txs)
 592         if other_txs is None:
 593             return None # not all txs present
 594         return dict(header=self.header, txs=[self.check(tracker)] + other_txs)
 595
 596
 597 class WeightsSkipList(forest.TrackerSkipList):
 598     # share_count, weights, total_weight
 599
 600     def get_delta(self, element):
 601         from p2pool.bitcoin import data as bitcoin_data
 602         share = self.tracker.items[element]
 603         att = bitcoin_data.target_to_average_attempts(share.target)
 604         return 1, {share.new_script: att*(65535-share.share_data['donation'])}, att*65535, att*share.share_data['donation']
 605
 606     def combine_deltas(self, (share_count1, weights1, total_weight1, total_donation_weight1), (share_count2, weights2, total_weight2, total_donation_weight2)):
 607         return share_count1 + share_count2, math.add_dicts(weights1, weights2), total_weight1 + total_weight2, total_donation_weight1 + total_donation_weight2
 608
 609     def initial_solution(self, start, (max_shares, desired_weight)):
 610         assert desired_weight % 65535 == 0, divmod(desired_weight, 65535)
 611         return 0, None, 0, 0
 612
 613     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)):
 614         if total_weight1 + total_weight2 > desired_weight and share_count2 == 1:
 615             assert (desired_weight - total_weight1) % 65535 == 0
 616             script, = weights2.iterkeys()
 617             new_weights = {script: (desired_weight - total_weight1)//65535*weights2[script]//(total_weight2//65535)}
 618             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)
 619         return share_count1 + share_count2, (weights_list, weights2), total_weight1 + total_weight2, total_donation_weight1 + total_donation_weight2
 620
 621     def judge(self, (share_count, weights_list, total_weight, total_donation_weight), (max_shares, desired_weight)):
 622         if share_count > max_shares or total_weight > desired_weight:
 623             return 1
 624         elif share_count == max_shares or total_weight == desired_weight:
 625             return 0
 626         else:
 627             return -1
 628
 629     def finalize(self, (share_count, weights_list, total_weight, total_donation_weight), (max_shares, desired_weight)):
 630         assert share_count <= max_shares and total_weight <= desired_weight
 631         assert share_count == max_shares or total_weight == desired_weight
 632         return math.add_dicts(*math.flatten_linked_list(weights_list)), total_weight, total_donation_weight
 633
 634 class OkayTracker(forest.Tracker):
 635     def __init__(self, net):
 636         forest.Tracker.__init__(self, delta_type=forest.get_attributedelta_type(dict(forest.AttributeDelta.attrs,
 637             work=lambda share: bitcoin_data.target_to_average_attempts(share.target),
 638             min_work=lambda share: bitcoin_data.target_to_average_attempts(share.max_target),
 639         )))
 640         self.net = net
 641         self.verified = forest.SubsetTracker(delta_type=forest.get_attributedelta_type(dict(forest.AttributeDelta.attrs,
 642             work=lambda share: bitcoin_data.target_to_average_attempts(share.target),
 643         )), subset_of=self)
 644         self.get_cumulative_weights = WeightsSkipList(self)
 645
 646     def attempt_verify(self, share):
 647         if share.hash in self.verified.items:
 648             return True
 649         height, last = self.get_height_and_last(share.hash)
 650         if height < self.net.CHAIN_LENGTH + 1 and last is not None:
 651             raise AssertionError()
 652         try:
 653             share.check(self)
 654         except:
 655             log.err(None, 'Share check failed:')
 656             return False
 657         else:
 658             self.verified.add(share)
 659             return True
 660
 661     def think(self, block_rel_height_func, previous_block, bits, known_txs):
 662         desired = set()
 663
 664         # O(len(self.heads))
 665         #   make 'unverified heads' set?
 666         # for each overall head, attempt verification
 667         # if it fails, attempt on parent, and repeat
 668         # if no successful verification because of lack of parents, request parent
 669         bads = set()
 670         for head in set(self.heads) - set(self.verified.heads):
 671             head_height, last = self.get_height_and_last(head)
 672
 673             for share in self.get_chain(head, head_height if last is None else min(5, max(0, head_height - self.net.CHAIN_LENGTH))):
 674                 if self.attempt_verify(share):
 675                     break
 676                 if share.hash in self.heads:
 677                     bads.add(share.hash)
 678             else:
 679                 if last is not None:
 680                     desired.add((
 681                         self.items[random.choice(list(self.reverse[last]))].peer,
 682                         last,
 683                         max(x.timestamp for x in self.get_chain(head, min(head_height, 5))),
 684                         min(x.target for x in self.get_chain(head, min(head_height, 5))),
 685                     ))
 686         for bad in bads:
 687             assert bad not in self.verified.items
 688             assert bad in self.heads
 689             if p2pool.DEBUG:
 690                 print "BAD", bad
 691             self.remove(bad)
 692
 693         # try to get at least CHAIN_LENGTH height for each verified head, requesting parents if needed
 694         for head in list(self.verified.heads):
 695             head_height, last_hash = self.verified.get_height_and_last(head)
 696             last_height, last_last_hash = self.get_height_and_last(last_hash)
 697             # XXX review boundary conditions
 698             want = max(self.net.CHAIN_LENGTH - head_height, 0)
 699             can = max(last_height - 1 - self.net.CHAIN_LENGTH, 0) if last_last_hash is not None else last_height
 700             get = min(want, can)
 701             #print 'Z', head_height, last_hash is None, last_height, last_last_hash is None, want, can, get
 702             for share in self.get_chain(last_hash, get):
 703                 if not self.attempt_verify(share):
 704                     break
 705             if head_height < self.net.CHAIN_LENGTH and last_last_hash is not None:
 706                 desired.add((
 707                     self.items[random.choice(list(self.verified.reverse[last_hash]))].peer,
 708                     last_last_hash,
 709                     max(x.timestamp for x in self.get_chain(head, min(head_height, 5))),
 710                     min(x.target for x in self.get_chain(head, min(head_height, 5))),
 711                 ))
 712
 713         # decide best tree
 714         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)
 715         if p2pool.DEBUG:
 716             print len(decorated_tails), 'tails:'
 717             for score, tail_hash in decorated_tails:
 718                 print format_hash(tail_hash), score
 719         best_tail_score, best_tail = decorated_tails[-1] if decorated_tails else (None, None)
 720
 721         # decide best verified head
 722         decorated_heads = sorted(((
 723             self.verified.get_work(self.verified.get_nth_parent_hash(h, min(5, self.verified.get_height(h)))),
 724             #self.items[h].peer is None,
 725             -self.items[h].should_punish_reason(previous_block, bits, self, known_txs)[0],
 726             -self.items[h].time_seen,
 727         ), h) for h in self.verified.tails.get(best_tail, []))
 728         if p2pool.DEBUG:
 729             print len(decorated_heads), 'heads. Top 10:'
 730             for score, head_hash in decorated_heads[-10:]:
 731                 print '   ', format_hash(head_hash), format_hash(self.items[head_hash].previous_hash), score
 732         best_head_score, best = decorated_heads[-1] if decorated_heads else (None, None)
 733
 734         if best is not None:
 735             best_share = self.items[best]
 736             punish, punish_reason = best_share.should_punish_reason(previous_block, bits, self, known_txs)
 737             if punish > 0:
 738                 print 'Punishing share for %r! Jumping from %s to %s!' % (punish_reason, format_hash(best), format_hash(best_share.previous_hash))
 739                 best = best_share.previous_hash
 740
 741             timestamp_cutoff = min(int(time.time()), best_share.timestamp) - 3600
 742             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
 743         else:
 744             timestamp_cutoff = int(time.time()) - 24*60*60
 745             target_cutoff = 2**256-1
 746
 747         if p2pool.DEBUG:
 748             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))
 749             for peer, hash, ts, targ in desired:
 750                 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
 751
 752         return best, [(peer, hash) for peer, hash, ts, targ in desired if ts >= timestamp_cutoff], decorated_heads
 753
 754     def score(self, share_hash, block_rel_height_func):
 755         # returns approximate lower bound on chain's hashrate in the last self.net.CHAIN_LENGTH*15//16*self.net.SHARE_PERIOD time
 756
 757         head_height = self.verified.get_height(share_hash)
 758         if head_height < self.net.CHAIN_LENGTH:
 759             return head_height, None
 760
 761         end_point = self.verified.get_nth_parent_hash(share_hash, self.net.CHAIN_LENGTH*15//16)
 762
 763         block_height = max(block_rel_height_func(share.header['previous_block']) for share in
 764             self.verified.get_chain(end_point, self.net.CHAIN_LENGTH//16))
 765
 766         return self.net.CHAIN_LENGTH, self.verified.get_delta(share_hash, end_point).work//((0 - block_height + 1)*self.net.PARENT.BLOCK_PERIOD)
 767
 768 def get_pool_attempts_per_second(tracker, previous_share_hash, dist, min_work=False, integer=False):
 769     assert dist >= 2
 770     near = tracker.items[previous_share_hash]
 771     far = tracker.items[tracker.get_nth_parent_hash(previous_share_hash, dist - 1)]
 772     attempts = tracker.get_delta(near.hash, far.hash).work if not min_work else tracker.get_delta(near.hash, far.hash).min_work
 773     time = near.timestamp - far.timestamp
 774     if time <= 0:
 775         time = 1
 776     if integer:
 777         return attempts//time
 778     return attempts/time
 779
 780 def get_average_stale_prop(tracker, share_hash, lookbehind):
 781     stales = sum(1 for share in tracker.get_chain(share_hash, lookbehind) if share.share_data['stale_info'] is not None)
 782     return stales/(lookbehind + stales)
 783
 784 def get_stale_counts(tracker, share_hash, lookbehind, rates=False):
 785     res = {}
 786     for share in tracker.get_chain(share_hash, lookbehind - 1):
 787         res['good'] = res.get('good', 0) + bitcoin_data.target_to_average_attempts(share.target)
 788         s = share.share_data['stale_info']
 789         if s is not None:
 790             res[s] = res.get(s, 0) + bitcoin_data.target_to_average_attempts(share.target)
 791     if rates:
 792         dt = tracker.items[share_hash].timestamp - tracker.items[tracker.get_nth_parent_hash(share_hash, lookbehind - 1)].timestamp
 793         res = dict((k, v/dt) for k, v in res.iteritems())
 794     return res
 795
 796 def get_user_stale_props(tracker, share_hash, lookbehind):
 797     res = {}
 798     for share in tracker.get_chain(share_hash, lookbehind - 1):
 799         stale, total = res.get(share.share_data['pubkey_hash'], (0, 0))
 800         total += 1
 801         if share.share_data['stale_info'] is not None:
 802             stale += 1
 803             total += 1
 804         res[share.share_data['pubkey_hash']] = stale, total
 805     return dict((pubkey_hash, stale/total) for pubkey_hash, (stale, total) in res.iteritems())
 806
 807 def get_expected_payouts(tracker, best_share_hash, block_target, subsidy, net):
 808     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))
 809     res = dict((script, subsidy*weight//total_weight) for script, weight in weights.iteritems())
 810     res[DONATION_SCRIPT] = res.get(DONATION_SCRIPT, 0) + subsidy - sum(res.itervalues())
 811     return res
 812
 813 def get_desired_version_counts(tracker, best_share_hash, dist):
 814     res = {}
 815     for share in tracker.get_chain(best_share_hash, dist):
 816         res[share.desired_version] = res.get(share.desired_version, 0) + bitcoin_data.target_to_average_attempts(share.target)
 817     return res
 818
 819 def get_warnings(tracker, best_share, net, bitcoind_warning, bitcoind_work_value):
 820     res = []
 821
 822     desired_version_counts = get_desired_version_counts(tracker, best_share,
 823         min(net.CHAIN_LENGTH, 60*60//net.SHARE_PERIOD, tracker.get_height(best_share)))
 824     majority_desired_version = max(desired_version_counts, key=lambda k: desired_version_counts[k])
 825     if majority_desired_version > NewShare.VERSION and desired_version_counts[majority_desired_version] > sum(desired_version_counts.itervalues())/2:
 826         res.append('A MAJORITY OF SHARES CONTAIN A VOTE FOR AN UNSUPPORTED SHARE IMPLEMENTATION! (v%i with %i%% support)\n'
 827             'An upgrade is likely necessary. Check http://p2pool.forre.st/ for more information.' % (
 828                 majority_desired_version, 100*desired_version_counts[majority_desired_version]/sum(desired_version_counts.itervalues())))
 829
 830     if bitcoind_warning is not None:
 831         res.append('(from bitcoind) %s' % (bitcoind_warning,))
 832
 833     if time.time() > bitcoind_work_value['last_update'] + 60:
 834         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']),))
 835
 836     return res
 837
 838 def format_hash(x):
 839     if x is None:
 840         return 'xxxxxxxx'
 841     return '%08x' % (x % 2**32)
 842
 843 class ShareStore(object):
 844     def __init__(self, prefix, net):
 845         self.filename = prefix
 846         self.dirname = os.path.dirname(os.path.abspath(prefix))
 847         self.filename = os.path.basename(os.path.abspath(prefix))
 848         self.net = net
 849         self.known = None # will be filename -> set of share hashes, set of verified hashes
 850         self.known_desired = None
 851
 852     def get_shares(self):
 853         if self.known is not None:
 854             raise AssertionError()
 855         known = {}
 856         filenames, next = self.get_filenames_and_next()
 857         for filename in filenames:
 858             share_hashes, verified_hashes = known.setdefault(filename, (set(), set()))
 859             with open(filename, 'rb') as f:
 860                 for line in f:
 861                     try:
 862                         type_id_str, data_hex = line.strip().split(' ')
 863                         type_id = int(type_id_str)
 864                         if type_id == 0:
 865                             pass
 866                         elif type_id == 1:
 867                             pass
 868                         elif type_id == 2:
 869                             verified_hash = int(data_hex, 16)
 870                             yield 'verified_hash', verified_hash
 871                             verified_hashes.add(verified_hash)
 872                         elif type_id == 5:
 873                             raw_share = share_type.unpack(data_hex.decode('hex'))
 874                             if raw_share['type'] in [0, 1, 2, 3, 6, 7]:
 875                                 continue
 876                             share = load_share(raw_share, self.net, None)
 877                             yield 'share', share
 878                             share_hashes.add(share.hash)
 879                         else:
 880                             raise NotImplementedError("share type %i" % (type_id,))
 881                     except Exception:
 882                         log.err(None, "HARMLESS error while reading saved shares, continuing where left off:")
 883         self.known = known
 884         self.known_desired = dict((k, (set(a), set(b))) for k, (a, b) in known.iteritems())
 885
 886     def _add_line(self, line):
 887         filenames, next = self.get_filenames_and_next()
 888         if filenames and os.path.getsize(filenames[-1]) < 10e6:
 889             filename = filenames[-1]
 890         else:
 891             filename = next
 892
 893         with open(filename, 'ab') as f:
 894             f.write(line + '\n')
 895
 896         return filename
 897
 898     def add_share(self, share):
 899         for filename, (share_hashes, verified_hashes) in self.known.iteritems():
 900             if share.hash in share_hashes:
 901                 break
 902         else:
 903             filename = self._add_line("%i %s" % (5, share_type.pack(share.as_share()).encode('hex')))
 904             share_hashes, verified_hashes = self.known.setdefault(filename, (set(), set()))
 905             share_hashes.add(share.hash)
 906         share_hashes, verified_hashes = self.known_desired.setdefault(filename, (set(), set()))
 907         share_hashes.add(share.hash)
 908
 909     def add_verified_hash(self, share_hash):
 910         for filename, (share_hashes, verified_hashes) in self.known.iteritems():
 911             if share_hash in verified_hashes:
 912                 break
 913         else:
 914             filename = self._add_line("%i %x" % (2, share_hash))
 915             share_hashes, verified_hashes = self.known.setdefault(filename, (set(), set()))
 916             verified_hashes.add(share_hash)
 917         share_hashes, verified_hashes = self.known_desired.setdefault(filename, (set(), set()))
 918         verified_hashes.add(share_hash)
 919
 920     def get_filenames_and_next(self):
 921         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())
 922         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)))
 923
 924     def forget_share(self, share_hash):
 925         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
 926             if share_hash in share_hashes:
 927                 share_hashes.remove(share_hash)
 928         self.check_remove()
 929
 930     def forget_verified_share(self, share_hash):
 931         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
 932             if share_hash in verified_hashes:
 933                 verified_hashes.remove(share_hash)
 934         self.check_remove()
 935
 936     def check_remove(self):
 937         to_remove = set()
 938         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
 939             #print filename, len(share_hashes) + len(verified_hashes)
 940             if not share_hashes and not verified_hashes:
 941                 to_remove.add(filename)
 942         for filename in to_remove:
 943             self.known.pop(filename)
 944             self.known_desired.pop(filename)
 945             os.remove(filename)
 946             print "REMOVED", filename