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_addr):
  43     assert peer_addr is None or isinstance(peer_addr, tuple)
  44     if share['type'] < Share.VERSION:
  45         from p2pool import p2p
  46         raise p2p.PeerMisbehavingError('sent an obsolete share')
  47     elif share['type'] == Share.VERSION:
  48         return Share(net, peer_addr, Share.share_type.unpack(share['contents']))
  49     elif share['type'] == NewShare.VERSION:
  50         return NewShare(net, peer_addr, NewShare.share_type.unpack(share['contents']))
  51     else:
  52         raise ValueError('unknown share type: %r' % (share['type'],))
  53
  54 DONATION_SCRIPT = '4104ffd03de44a6e11b9917f3a29f9443283d9871c9d743ef30d5eddcd37094b64d1b3d8090496b53256786bf5c82932ec23c3b74d9f05a6f95a8b5529352656664bac'.decode('hex')
  55
  56 class NewShare(object):
  57     VERSION = 13
  58     VOTING_VERSION = 13
  59     SUCCESSOR = None
  60
  61     small_block_header_type = pack.ComposedType([
  62         ('version', pack.VarIntType()),
  63         ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))),
  64         ('timestamp', pack.IntType(32)),
  65         ('bits', bitcoin_data.FloatingIntegerType()),
  66         ('nonce', pack.IntType(32)),
  67     ])
  68
  69     share_info_type = pack.ComposedType([
  70         ('share_data', 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         ('new_transaction_hashes', pack.ListType(pack.IntType(256))),
  81         ('transaction_hash_refs', pack.ListType(pack.VarIntType(), 2)), # pairs of share_count, tx_count
  82         ('far_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
  83         ('max_bits', bitcoin_data.FloatingIntegerType()),
  84         ('bits', bitcoin_data.FloatingIntegerType()),
  85         ('timestamp', pack.IntType(32)),
  86         ('absheight', pack.IntType(32)),
  87         ('abswork', pack.IntType(128)),
  88     ])
  89
  90     share_type = pack.ComposedType([
  91         ('min_header', small_block_header_type),
  92         ('share_info', share_info_type),
  93         ('ref_merkle_link', pack.ComposedType([
  94             ('branch', pack.ListType(pack.IntType(256))),
  95             ('index', pack.IntType(0)),
  96         ])),
  97         ('last_txout_nonce', pack.IntType(64)),
  98         ('hash_link', hash_link_type),
  99         ('merkle_link', pack.ComposedType([
 100             ('branch', pack.ListType(pack.IntType(256))),
 101             ('index', pack.IntType(0)), # it will always be 0
 102         ])),
 103     ])
 104
 105     ref_type = pack.ComposedType([
 106         ('identifier', pack.FixedStrType(64//8)),
 107         ('share_info', share_info_type),
 108     ])
 109
 110     gentx_before_refhash = pack.VarStrType().pack(DONATION_SCRIPT) + pack.IntType(64).pack(0) + pack.VarStrType().pack('\x6a\x28' + pack.IntType(256).pack(0) + pack.IntType(64).pack(0))[:3]
 111
 112     @classmethod
 113     def generate_transaction(cls, tracker, share_data, block_target, desired_timestamp, desired_target, ref_merkle_link, desired_other_transaction_hashes_and_fees, net, known_txs=None, last_txout_nonce=0, base_subsidy=None):
 114         previous_share = tracker.items[share_data['previous_share_hash']] if share_data['previous_share_hash'] is not None else None
 115
 116         height, last = tracker.get_height_and_last(share_data['previous_share_hash'])
 117         assert height >= net.REAL_CHAIN_LENGTH or last is None
 118         if height < net.TARGET_LOOKBEHIND:
 119             pre_target3 = net.MAX_TARGET
 120         else:
 121             attempts_per_second = get_pool_attempts_per_second(tracker, share_data['previous_share_hash'], net.TARGET_LOOKBEHIND, min_work=True, integer=True)
 122             pre_target = 2**256//(net.NEW_SHARE_PERIOD*attempts_per_second) - 1 if attempts_per_second else 2**256-1
 123             pre_target2 = math.clip(pre_target, (previous_share.max_target*9//10, previous_share.max_target*11//10))
 124             pre_target3 = math.clip(pre_target2, (net.MIN_TARGET, net.MAX_TARGET))
 125         max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
 126         bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//10, pre_target3)))
 127
 128         new_transaction_hashes = []
 129         new_transaction_size = 0
 130         transaction_hash_refs = []
 131         other_transaction_hashes = []
 132
 133         past_shares = list(tracker.get_chain(share_data['previous_share_hash'], min(height, 100)))
 134         tx_hash_to_this = {}
 135         for i, share in enumerate(past_shares):
 136             for j, tx_hash in enumerate(share.new_transaction_hashes):
 137                 if tx_hash not in tx_hash_to_this:
 138                     tx_hash_to_this[tx_hash] = [1+i, j] # share_count, tx_count
 139         for tx_hash, fee in desired_other_transaction_hashes_and_fees:
 140             if tx_hash in tx_hash_to_this:
 141                 this = tx_hash_to_this[tx_hash]
 142             else:
 143                 if known_txs is not None:
 144                     this_size = bitcoin_data.tx_type.packed_size(known_txs[tx_hash])
 145                     if new_transaction_size + this_size > 50000: # only allow 50 kB of new txns/share
 146                         break
 147                     new_transaction_size += this_size
 148                 new_transaction_hashes.append(tx_hash)
 149                 this = [0, len(new_transaction_hashes)-1]
 150             transaction_hash_refs.extend(this)
 151             other_transaction_hashes.append(tx_hash)
 152
 153         included_transactions = set(other_transaction_hashes)
 154         removed_fees = [fee for tx_hash, fee in desired_other_transaction_hashes_and_fees if tx_hash not in included_transactions]
 155         definite_fees = sum(0 if fee is None else fee for tx_hash, fee in desired_other_transaction_hashes_and_fees if tx_hash in included_transactions)
 156         if None not in removed_fees:
 157             share_data = dict(share_data, subsidy=share_data['subsidy'] - sum(removed_fees))
 158         else:
 159             assert base_subsidy is not None
 160             share_data = dict(share_data, subsidy=base_subsidy + definite_fees)
 161
 162         weights, total_weight, donation_weight = tracker.get_cumulative_weights(previous_share.share_data['previous_share_hash'] if previous_share is not None else None,
 163             min(height, net.REAL_CHAIN_LENGTH-1),
 164             65535*net.NEW_SPREAD*bitcoin_data.target_to_average_attempts(block_target),
 165         )
 166         assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
 167
 168         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
 169         this_script = bitcoin_data.pubkey_hash_to_script2(share_data['pubkey_hash'])
 170         amounts[this_script] = amounts.get(this_script, 0) + share_data['subsidy']//200 # 0.5% goes to block finder
 171         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
 172
 173         if sum(amounts.itervalues()) != share_data['subsidy'] or any(x < 0 for x in amounts.itervalues()):
 174             raise ValueError()
 175
 176         dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit
 177
 178         share_info = dict(
 179             share_data=share_data,
 180             far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
 181             max_bits=max_bits,
 182             bits=bits,
 183             timestamp=math.clip(desired_timestamp, (
 184                 (previous_share.timestamp + net.NEW_SHARE_PERIOD) - (net.NEW_SHARE_PERIOD - 1), # = previous_share.timestamp + 1
 185                 (previous_share.timestamp + net.NEW_SHARE_PERIOD) + (net.NEW_SHARE_PERIOD - 1),
 186             )) if previous_share is not None else desired_timestamp,
 187             new_transaction_hashes=new_transaction_hashes,
 188             transaction_hash_refs=transaction_hash_refs,
 189             absheight=((previous_share.absheight if previous_share is not None else 0) + 1) % 2**32,
 190             abswork=((previous_share.abswork if previous_share is not None else 0) + bitcoin_data.target_to_average_attempts(bits.target)) % 2**128,
 191         )
 192
 193         gentx = dict(
 194             version=1,
 195             tx_ins=[dict(
 196                 previous_output=None,
 197                 sequence=None,
 198                 script=share_data['coinbase'],
 199             )],
 200             tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT] + [dict(
 201                 value=0,
 202                 script='\x6a\x28' + cls.get_ref_hash(net, share_info, ref_merkle_link) + pack.IntType(64).pack(last_txout_nonce),
 203             )],
 204             lock_time=0,
 205         )
 206
 207         def get_share(header, last_txout_nonce=last_txout_nonce):
 208             min_header = dict(header); del min_header['merkle_root']
 209             share = cls(net, None, dict(
 210                 min_header=min_header,
 211                 share_info=share_info,
 212                 ref_merkle_link=dict(branch=[], index=0),
 213                 last_txout_nonce=last_txout_nonce*2**32,
 214                 hash_link=prefix_to_hash_link(bitcoin_data.tx_type.pack(gentx)[:-32-8-4], cls.gentx_before_refhash),
 215                 merkle_link=bitcoin_data.calculate_merkle_link([None] + other_transaction_hashes, 0),
 216             ))
 217             assert share.header == header # checks merkle_root
 218             return share
 219
 220         return share_info, gentx, other_transaction_hashes, get_share
 221
 222     @classmethod
 223     def get_ref_hash(cls, net, share_info, ref_merkle_link):
 224         return pack.IntType(256).pack(bitcoin_data.check_merkle_link(bitcoin_data.hash256(cls.ref_type.pack(dict(
 225             identifier=net.IDENTIFIER,
 226             share_info=share_info,
 227         ))), ref_merkle_link))
 228
 229     __slots__ = 'net peer_addr 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 absheight abswork'.split(' ')
 230
 231     def __init__(self, net, peer_addr, contents):
 232         self.net = net
 233         self.peer_addr = peer_addr
 234         self.contents = contents
 235
 236         self.min_header = contents['min_header']
 237         self.share_info = contents['share_info']
 238         self.hash_link = contents['hash_link']
 239         self.merkle_link = contents['merkle_link']
 240
 241         if not (2 <= len(self.share_info['share_data']['coinbase']) <= 100):
 242             raise ValueError('''bad coinbase size! %i bytes''' % (len(self.share_info['share_data']['coinbase']),))
 243
 244         if len(self.merkle_link['branch']) > 16:
 245             raise ValueError('merkle branch too long!')
 246
 247         assert not self.hash_link['extra_data'], repr(self.hash_link['extra_data'])
 248
 249         self.share_data = self.share_info['share_data']
 250         self.max_target = self.share_info['max_bits'].target
 251         self.target = self.share_info['bits'].target
 252         self.timestamp = self.share_info['timestamp']
 253         self.previous_hash = self.share_data['previous_share_hash']
 254         self.new_script = bitcoin_data.pubkey_hash_to_script2(self.share_data['pubkey_hash'])
 255         self.desired_version = self.share_data['desired_version']
 256         self.absheight = self.share_info['absheight']
 257         self.abswork = self.share_info['abswork']
 258
 259         n = set()
 260         for share_count, tx_count in self.iter_transaction_hash_refs():
 261             assert share_count < 110
 262             if share_count == 0:
 263                 n.add(tx_count)
 264         assert n == set(range(len(self.share_info['new_transaction_hashes'])))
 265
 266         self.gentx_hash = check_hash_link(
 267             self.hash_link,
 268             self.get_ref_hash(net, self.share_info, contents['ref_merkle_link']) + pack.IntType(64).pack(self.contents['last_txout_nonce']) + pack.IntType(32).pack(0),
 269             self.gentx_before_refhash,
 270         )
 271         merkle_root = bitcoin_data.check_merkle_link(self.gentx_hash, self.merkle_link)
 272         self.header = dict(self.min_header, merkle_root=merkle_root)
 273         self.pow_hash = net.PARENT.POW_FUNC(bitcoin_data.block_header_type.pack(self.header))
 274         self.hash = self.header_hash = bitcoin_data.hash256(bitcoin_data.block_header_type.pack(self.header))
 275
 276         if self.target > net.MAX_TARGET:
 277             from p2pool import p2p
 278             raise p2p.PeerMisbehavingError('share target invalid')
 279
 280         if self.pow_hash > self.target:
 281             from p2pool import p2p
 282             raise p2p.PeerMisbehavingError('share PoW invalid')
 283
 284         self.new_transaction_hashes = self.share_info['new_transaction_hashes']
 285
 286         # XXX eww
 287         self.time_seen = time.time()
 288
 289     def __repr__(self):
 290         return 'Share' + repr((self.net, self.peer_addr, self.contents))
 291
 292     def as_share(self):
 293         return dict(type=self.VERSION, contents=self.share_type.pack(self.contents))
 294
 295     def iter_transaction_hash_refs(self):
 296         return zip(self.share_info['transaction_hash_refs'][::2], self.share_info['transaction_hash_refs'][1::2])
 297
 298     def check(self, tracker):
 299         from p2pool import p2p
 300         if self.share_data['previous_share_hash'] is not None:
 301             previous_share = tracker.items[self.share_data['previous_share_hash']]
 302             if type(self) is type(previous_share):
 303                 pass
 304             elif type(self) is type(previous_share).SUCCESSOR:
 305                 if tracker.get_height(previous_share.hash) < self.net.CHAIN_LENGTH:
 306                     from p2pool import p2p
 307                     raise p2p.PeerMisbehavingError('switch without enough history')
 308
 309                 # switch only valid if 85% of hashes in [self.net.CHAIN_LENGTH*9//10, self.net.CHAIN_LENGTH] for new version
 310                 counts = get_desired_version_counts(tracker,
 311                     tracker.get_nth_parent_hash(previous_share.hash, self.net.CHAIN_LENGTH*9//10), self.net.CHAIN_LENGTH//10)
 312                 if counts.get(self.VERSION, 0) < sum(counts.itervalues())*85//100:
 313                     raise p2p.PeerMisbehavingError('switch without enough hash power upgraded')
 314             else:
 315                 raise p2p.PeerMisbehavingError('''%s can't follow %s''' % (type(self).__name__, type(previous_share).__name__))
 316
 317         other_tx_hashes = [tracker.items[tracker.get_nth_parent_hash(self.hash, share_count)].share_info['new_transaction_hashes'][tx_count] for share_count, tx_count in self.iter_transaction_hash_refs()]
 318
 319         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'], [(h, None) for h in other_tx_hashes], self.net, last_txout_nonce=self.contents['last_txout_nonce'])
 320         assert other_tx_hashes2 == other_tx_hashes
 321         if share_info != self.share_info:
 322             raise ValueError('share_info invalid')
 323         if bitcoin_data.hash256(bitcoin_data.tx_type.pack(gentx)) != self.gentx_hash:
 324             raise ValueError('''gentx doesn't match hash_link''')
 325
 326         if bitcoin_data.calculate_merkle_link([None] + other_tx_hashes, 0) != self.merkle_link:
 327             raise ValueError('merkle_link and other_tx_hashes do not match')
 328
 329         return gentx # only used by as_block
 330
 331     def get_other_tx_hashes(self, tracker):
 332         parents_needed = max(share_count for share_count, tx_count in self.iter_transaction_hash_refs()) if self.share_info['transaction_hash_refs'] else 0
 333         parents = tracker.get_height(self.hash) - 1
 334         if parents < parents_needed:
 335             return None
 336         last_shares = list(tracker.get_chain(self.hash, parents_needed + 1))
 337         return [last_shares[share_count].share_info['new_transaction_hashes'][tx_count] for share_count, tx_count in self.iter_transaction_hash_refs()]
 338
 339     def _get_other_txs(self, tracker, known_txs):
 340         other_tx_hashes = self.get_other_tx_hashes(tracker)
 341         if other_tx_hashes is None:
 342             return None # not all parents present
 343
 344         if not all(tx_hash in known_txs for tx_hash in other_tx_hashes):
 345             return None # not all txs present
 346
 347         return [known_txs[tx_hash] for tx_hash in other_tx_hashes]
 348
 349     def should_punish_reason(self, previous_block, bits, tracker, known_txs):
 350         if (self.header['previous_block'], self.header['bits']) != (previous_block, bits) and self.header_hash != previous_block and self.peer_addr is not None:
 351             return True, 'Block-stale detected! %x < %x' % (self.header['previous_block'], previous_block)
 352
 353         if self.pow_hash <= self.header['bits'].target:
 354             return -1, 'block solution'
 355
 356         other_txs = self._get_other_txs(tracker, known_txs)
 357         if other_txs is None:
 358             if self.time_seen != 0: # ignore if loaded from ShareStore
 359                 return True, 'not all txs present'
 360         else:
 361             all_txs_size = sum(bitcoin_data.tx_type.packed_size(tx) for tx in other_txs)
 362             if all_txs_size > 1000000:
 363                 return True, 'txs over block size limit'
 364
 365             new_txs_size = sum(bitcoin_data.tx_type.packed_size(known_txs[tx_hash]) for tx_hash in self.share_info['new_transaction_hashes'])
 366             if new_txs_size > 50000:
 367                 return True, 'new txs over limit'
 368
 369         return False, None
 370
 371     def as_block(self, tracker, known_txs):
 372         other_txs = self._get_other_txs(tracker, known_txs)
 373         if other_txs is None:
 374             return None # not all txs present
 375         return dict(header=self.header, txs=[self.check(tracker)] + other_txs)
 376
 377 class Share(object):
 378     VERSION = 9
 379     VOTING_VERSION = 11
 380     SUCCESSOR = NewShare
 381
 382     absheight = abswork = 0
 383
 384     small_block_header_type = pack.ComposedType([
 385         ('version', pack.VarIntType()),
 386         ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))),
 387         ('timestamp', pack.IntType(32)),
 388         ('bits', bitcoin_data.FloatingIntegerType()),
 389         ('nonce', pack.IntType(32)),
 390     ])
 391
 392     share_info_type = pack.ComposedType([
 393         ('share_data', pack.ComposedType([
 394             ('previous_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
 395             ('coinbase', pack.VarStrType()),
 396             ('nonce', pack.IntType(32)),
 397             ('pubkey_hash', pack.IntType(160)),
 398             ('subsidy', pack.IntType(64)),
 399             ('donation', pack.IntType(16)),
 400             ('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)))),
 401             ('desired_version', pack.VarIntType()),
 402         ])),
 403         ('new_transaction_hashes', pack.ListType(pack.IntType(256))),
 404         ('transaction_hash_refs', pack.ListType(pack.VarIntType(), 2)), # pairs of share_count, tx_count
 405         ('far_share_hash', pack.PossiblyNoneType(0, pack.IntType(256))),
 406         ('max_bits', bitcoin_data.FloatingIntegerType()),
 407         ('bits', bitcoin_data.FloatingIntegerType()),
 408         ('timestamp', pack.IntType(32)),
 409     ])
 410
 411     share_type = pack.ComposedType([
 412         ('min_header', small_block_header_type),
 413         ('share_info', share_info_type),
 414         ('ref_merkle_link', pack.ComposedType([
 415             ('branch', pack.ListType(pack.IntType(256))),
 416             ('index', pack.IntType(0)),
 417         ])),
 418         ('last_txout_nonce', pack.IntType(32)),
 419         ('hash_link', hash_link_type),
 420         ('merkle_link', pack.ComposedType([
 421             ('branch', pack.ListType(pack.IntType(256))),
 422             ('index', pack.IntType(0)), # it will always be 0
 423         ])),
 424     ])
 425
 426     ref_type = pack.ComposedType([
 427         ('identifier', pack.FixedStrType(64//8)),
 428         ('share_info', share_info_type),
 429     ])
 430
 431     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]
 432
 433     @classmethod
 434     def generate_transaction(cls, tracker, share_data, block_target, desired_timestamp, desired_target, ref_merkle_link, desired_other_transaction_hashes_and_fees, net, known_txs=None, last_txout_nonce=0, base_subsidy=None):
 435         previous_share = tracker.items[share_data['previous_share_hash']] if share_data['previous_share_hash'] is not None else None
 436
 437         height, last = tracker.get_height_and_last(share_data['previous_share_hash'])
 438         assert height >= net.REAL_CHAIN_LENGTH or last is None
 439         if height < net.TARGET_LOOKBEHIND:
 440             pre_target3 = net.MAX_TARGET
 441         else:
 442             attempts_per_second = get_pool_attempts_per_second(tracker, share_data['previous_share_hash'], net.TARGET_LOOKBEHIND, min_work=True, integer=True)
 443             pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1 if attempts_per_second else 2**256-1
 444             pre_target2 = math.clip(pre_target, (previous_share.max_target*9//10, previous_share.max_target*11//10))
 445             pre_target3 = math.clip(pre_target2, (net.MIN_TARGET, net.MAX_TARGET))
 446         max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
 447         bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//10, pre_target3)))
 448
 449         new_transaction_hashes = []
 450         new_transaction_size = 0
 451         transaction_hash_refs = []
 452         other_transaction_hashes = []
 453
 454         past_shares = list(tracker.get_chain(share_data['previous_share_hash'], min(height, 100)))
 455         tx_hash_to_this = {}
 456         for i, share in enumerate(past_shares):
 457             for j, tx_hash in enumerate(share.new_transaction_hashes):
 458                 if tx_hash not in tx_hash_to_this:
 459                     tx_hash_to_this[tx_hash] = [1+i, j] # share_count, tx_count
 460         for tx_hash, fee in desired_other_transaction_hashes_and_fees:
 461             if tx_hash in tx_hash_to_this:
 462                 this = tx_hash_to_this[tx_hash]
 463             else:
 464                 if known_txs is not None:
 465                     this_size = bitcoin_data.tx_type.packed_size(known_txs[tx_hash])
 466                     if new_transaction_size + this_size > 50000: # only allow 50 kB of new txns/share
 467                         break
 468                     new_transaction_size += this_size
 469                 new_transaction_hashes.append(tx_hash)
 470                 this = [0, len(new_transaction_hashes)-1]
 471             transaction_hash_refs.extend(this)
 472             other_transaction_hashes.append(tx_hash)
 473
 474         included_transactions = set(other_transaction_hashes)
 475         removed_fees = [fee for tx_hash, fee in desired_other_transaction_hashes_and_fees if tx_hash not in included_transactions]
 476         definite_fees = sum(0 if fee is None else fee for tx_hash, fee in desired_other_transaction_hashes_and_fees if tx_hash in included_transactions)
 477         if None not in removed_fees:
 478             share_data = dict(share_data, subsidy=share_data['subsidy'] - sum(removed_fees))
 479         else:
 480             assert base_subsidy is not None
 481             share_data = dict(share_data, subsidy=base_subsidy + definite_fees)
 482
 483         weights, total_weight, donation_weight = tracker.get_cumulative_weights(share_data['previous_share_hash'],
 484             min(height, net.REAL_CHAIN_LENGTH),
 485             65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target),
 486         )
 487         assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
 488
 489         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
 490         this_script = bitcoin_data.pubkey_hash_to_script2(share_data['pubkey_hash'])
 491         amounts[this_script] = amounts.get(this_script, 0) + share_data['subsidy']//200 # 0.5% goes to block finder
 492         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
 493
 494         if sum(amounts.itervalues()) != share_data['subsidy'] or any(x < 0 for x in amounts.itervalues()):
 495             raise ValueError()
 496
 497         dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit
 498
 499         share_info = dict(
 500             share_data=share_data,
 501             far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
 502             max_bits=max_bits,
 503             bits=bits,
 504             timestamp=math.clip(desired_timestamp, (
 505                 (previous_share.timestamp + net.SHARE_PERIOD) - (net.SHARE_PERIOD - 1), # = previous_share.timestamp + 1
 506                 (previous_share.timestamp + net.SHARE_PERIOD) + (net.SHARE_PERIOD - 1),
 507             )) if previous_share is not None else desired_timestamp,
 508             new_transaction_hashes=new_transaction_hashes,
 509             transaction_hash_refs=transaction_hash_refs,
 510         )
 511
 512         gentx = dict(
 513             version=1,
 514             tx_ins=[dict(
 515                 previous_output=None,
 516                 sequence=None,
 517                 script=share_data['coinbase'],
 518             )],
 519             tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT] + [dict(
 520                 value=0,
 521                 script='\x24' + cls.get_ref_hash(net, share_info, ref_merkle_link) + pack.IntType(32).pack(last_txout_nonce),
 522             )],
 523             lock_time=0,
 524         )
 525
 526         def get_share(header, last_txout_nonce=last_txout_nonce):
 527             min_header = dict(header); del min_header['merkle_root']
 528             share = cls(net, None, dict(
 529                 min_header=min_header,
 530                 share_info=share_info,
 531                 ref_merkle_link=dict(branch=[], index=0),
 532                 last_txout_nonce=last_txout_nonce,
 533                 hash_link=prefix_to_hash_link(bitcoin_data.tx_type.pack(gentx)[:-32-4-4], cls.gentx_before_refhash),
 534                 merkle_link=bitcoin_data.calculate_merkle_link([None] + other_transaction_hashes, 0),
 535             ))
 536             assert share.header == header # checks merkle_root
 537             return share
 538
 539         return share_info, gentx, other_transaction_hashes, get_share
 540
 541     @classmethod
 542     def get_ref_hash(cls, net, share_info, ref_merkle_link):
 543         return pack.IntType(256).pack(bitcoin_data.check_merkle_link(bitcoin_data.hash256(cls.ref_type.pack(dict(
 544             identifier=net.IDENTIFIER,
 545             share_info=share_info,
 546         ))), ref_merkle_link))
 547
 548     __slots__ = 'net peer_addr 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(' ')
 549
 550     def __init__(self, net, peer_addr, contents):
 551         self.net = net
 552         self.peer_addr = peer_addr
 553         self.contents = contents
 554
 555         self.min_header = contents['min_header']
 556         self.share_info = contents['share_info']
 557         self.hash_link = contents['hash_link']
 558         self.merkle_link = contents['merkle_link']
 559
 560         if not (2 <= len(self.share_info['share_data']['coinbase']) <= 100):
 561             raise ValueError('''bad coinbase size! %i bytes''' % (len(self.share_info['share_data']['coinbase']),))
 562
 563         if len(self.merkle_link['branch']) > 16:
 564             raise ValueError('merkle branch too long!')
 565
 566         assert not self.hash_link['extra_data'], repr(self.hash_link['extra_data'])
 567
 568         self.share_data = self.share_info['share_data']
 569         self.max_target = self.share_info['max_bits'].target
 570         self.target = self.share_info['bits'].target
 571         self.timestamp = self.share_info['timestamp']
 572         self.previous_hash = self.share_data['previous_share_hash']
 573         self.new_script = bitcoin_data.pubkey_hash_to_script2(self.share_data['pubkey_hash'])
 574         self.desired_version = self.share_data['desired_version']
 575
 576         n = set()
 577         for share_count, tx_count in self.iter_transaction_hash_refs():
 578             assert share_count < 110
 579             if share_count == 0:
 580                 n.add(tx_count)
 581         assert n == set(range(len(self.share_info['new_transaction_hashes'])))
 582
 583         self.gentx_hash = check_hash_link(
 584             self.hash_link,
 585             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),
 586             self.gentx_before_refhash,
 587         )
 588         merkle_root = bitcoin_data.check_merkle_link(self.gentx_hash, self.merkle_link)
 589         self.header = dict(self.min_header, merkle_root=merkle_root)
 590         self.pow_hash = net.PARENT.POW_FUNC(bitcoin_data.block_header_type.pack(self.header))
 591         self.hash = self.header_hash = bitcoin_data.hash256(bitcoin_data.block_header_type.pack(self.header))
 592
 593         if self.target > net.MAX_TARGET:
 594             from p2pool import p2p
 595             raise p2p.PeerMisbehavingError('share target invalid')
 596
 597         if self.pow_hash > self.target:
 598             from p2pool import p2p
 599             raise p2p.PeerMisbehavingError('share PoW invalid')
 600
 601         self.new_transaction_hashes = self.share_info['new_transaction_hashes']
 602
 603         # XXX eww
 604         self.time_seen = time.time()
 605
 606     def __repr__(self):
 607         return 'Share' + repr((self.net, self.peer_addr, self.contents))
 608
 609     def as_share(self):
 610         return dict(type=self.VERSION, contents=self.share_type.pack(self.contents))
 611
 612     def iter_transaction_hash_refs(self):
 613         return zip(self.share_info['transaction_hash_refs'][::2], self.share_info['transaction_hash_refs'][1::2])
 614
 615     def check(self, tracker):
 616         from p2pool import p2p
 617         if self.share_data['previous_share_hash'] is not None:
 618             previous_share = tracker.items[self.share_data['previous_share_hash']]
 619             if type(self) is type(previous_share):
 620                 pass
 621             elif type(self) is type(previous_share).SUCCESSOR:
 622                 if tracker.get_height(previous_share.hash) < self.net.CHAIN_LENGTH:
 623                     from p2pool import p2p
 624                     raise p2p.PeerMisbehavingError('switch without enough history')
 625
 626                 # switch only valid if 85% of hashes in [self.net.CHAIN_LENGTH*9//10, self.net.CHAIN_LENGTH] for new version
 627                 counts = get_desired_version_counts(tracker,
 628                     tracker.get_nth_parent_hash(previous_share.hash, self.net.CHAIN_LENGTH*9//10), self.net.CHAIN_LENGTH//10)
 629                 if counts.get(self.VERSION, 0) < sum(counts.itervalues())*85//100:
 630                     raise p2p.PeerMisbehavingError('switch without enough hash power upgraded')
 631             else:
 632                 raise p2p.PeerMisbehavingError('''%s can't follow %s''' % (type(self).__name__, type(previous_share).__name__))
 633
 634         other_tx_hashes = [tracker.items[tracker.get_nth_parent_hash(self.hash, share_count)].share_info['new_transaction_hashes'][tx_count] for share_count, tx_count in self.iter_transaction_hash_refs()]
 635
 636         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'], [(h, None) for h in other_tx_hashes], self.net, last_txout_nonce=self.contents['last_txout_nonce'])
 637         assert other_tx_hashes2 == other_tx_hashes
 638         if share_info != self.share_info:
 639             raise ValueError('share_info invalid')
 640         if bitcoin_data.hash256(bitcoin_data.tx_type.pack(gentx)) != self.gentx_hash:
 641             raise ValueError('''gentx doesn't match hash_link''')
 642
 643         if bitcoin_data.calculate_merkle_link([None] + other_tx_hashes, 0) != self.merkle_link:
 644             raise ValueError('merkle_link and other_tx_hashes do not match')
 645
 646         return gentx # only used by as_block
 647
 648     def get_other_tx_hashes(self, tracker):
 649         parents_needed = max(share_count for share_count, tx_count in self.iter_transaction_hash_refs()) if self.share_info['transaction_hash_refs'] else 0
 650         parents = tracker.get_height(self.hash) - 1
 651         if parents < parents_needed:
 652             return None
 653         last_shares = list(tracker.get_chain(self.hash, parents_needed + 1))
 654         return [last_shares[share_count].share_info['new_transaction_hashes'][tx_count] for share_count, tx_count in self.iter_transaction_hash_refs()]
 655
 656     def _get_other_txs(self, tracker, known_txs):
 657         other_tx_hashes = self.get_other_tx_hashes(tracker)
 658         if other_tx_hashes is None:
 659             return None # not all parents present
 660
 661         if not all(tx_hash in known_txs for tx_hash in other_tx_hashes):
 662             return None # not all txs present
 663
 664         return [known_txs[tx_hash] for tx_hash in other_tx_hashes]
 665
 666     def should_punish_reason(self, previous_block, bits, tracker, known_txs):
 667         if (self.header['previous_block'], self.header['bits']) != (previous_block, bits) and self.header_hash != previous_block and self.peer_addr is not None:
 668             return True, 'Block-stale detected! %x < %x' % (self.header['previous_block'], previous_block)
 669
 670         if self.pow_hash <= self.header['bits'].target:
 671             return -1, 'block solution'
 672
 673         other_txs = self._get_other_txs(tracker, known_txs)
 674         if other_txs is None:
 675             if self.time_seen != 0: # ignore if loaded from ShareStore
 676                 return True, 'not all txs present'
 677         else:
 678             all_txs_size = sum(bitcoin_data.tx_type.packed_size(tx) for tx in other_txs)
 679             if all_txs_size > 1000000:
 680                 return True, 'txs over block size limit'
 681
 682             new_txs_size = sum(bitcoin_data.tx_type.packed_size(known_txs[tx_hash]) for tx_hash in self.share_info['new_transaction_hashes'])
 683             if new_txs_size > 50000:
 684                 return True, 'new txs over limit'
 685
 686         return False, None
 687
 688     def as_block(self, tracker, known_txs):
 689         other_txs = self._get_other_txs(tracker, known_txs)
 690         if other_txs is None:
 691             return None # not all txs present
 692         return dict(header=self.header, txs=[self.check(tracker)] + other_txs)
 693
 694
 695
 696 class WeightsSkipList(forest.TrackerSkipList):
 697     # share_count, weights, total_weight
 698
 699     def get_delta(self, element):
 700         from p2pool.bitcoin import data as bitcoin_data
 701         share = self.tracker.items[element]
 702         att = bitcoin_data.target_to_average_attempts(share.target)
 703         return 1, {share.new_script: att*(65535-share.share_data['donation'])}, att*65535, att*share.share_data['donation']
 704
 705     def combine_deltas(self, (share_count1, weights1, total_weight1, total_donation_weight1), (share_count2, weights2, total_weight2, total_donation_weight2)):
 706         return share_count1 + share_count2, math.add_dicts(weights1, weights2), total_weight1 + total_weight2, total_donation_weight1 + total_donation_weight2
 707
 708     def initial_solution(self, start, (max_shares, desired_weight)):
 709         assert desired_weight % 65535 == 0, divmod(desired_weight, 65535)
 710         return 0, None, 0, 0
 711
 712     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)):
 713         if total_weight1 + total_weight2 > desired_weight and share_count2 == 1:
 714             assert (desired_weight - total_weight1) % 65535 == 0
 715             script, = weights2.iterkeys()
 716             new_weights = {script: (desired_weight - total_weight1)//65535*weights2[script]//(total_weight2//65535)}
 717             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)
 718         return share_count1 + share_count2, (weights_list, weights2), total_weight1 + total_weight2, total_donation_weight1 + total_donation_weight2
 719
 720     def judge(self, (share_count, weights_list, total_weight, total_donation_weight), (max_shares, desired_weight)):
 721         if share_count > max_shares or total_weight > desired_weight:
 722             return 1
 723         elif share_count == max_shares or total_weight == desired_weight:
 724             return 0
 725         else:
 726             return -1
 727
 728     def finalize(self, (share_count, weights_list, total_weight, total_donation_weight), (max_shares, desired_weight)):
 729         assert share_count <= max_shares and total_weight <= desired_weight
 730         assert share_count == max_shares or total_weight == desired_weight
 731         return math.add_dicts(*math.flatten_linked_list(weights_list)), total_weight, total_donation_weight
 732
 733 class OkayTracker(forest.Tracker):
 734     def __init__(self, net):
 735         forest.Tracker.__init__(self, delta_type=forest.get_attributedelta_type(dict(forest.AttributeDelta.attrs,
 736             work=lambda share: bitcoin_data.target_to_average_attempts(share.target),
 737             min_work=lambda share: bitcoin_data.target_to_average_attempts(share.max_target),
 738         )))
 739         self.net = net
 740         self.verified = forest.SubsetTracker(delta_type=forest.get_attributedelta_type(dict(forest.AttributeDelta.attrs,
 741             work=lambda share: bitcoin_data.target_to_average_attempts(share.target),
 742         )), subset_of=self)
 743         self.get_cumulative_weights = WeightsSkipList(self)
 744
 745     def attempt_verify(self, share):
 746         if share.hash in self.verified.items:
 747             return True
 748         height, last = self.get_height_and_last(share.hash)
 749         if height < self.net.CHAIN_LENGTH + 1 and last is not None:
 750             raise AssertionError()
 751         try:
 752             share.check(self)
 753         except:
 754             log.err(None, 'Share check failed:')
 755             return False
 756         else:
 757             self.verified.add(share)
 758             return True
 759
 760     def think(self, block_rel_height_func, previous_block, bits, known_txs):
 761         desired = set()
 762
 763         # O(len(self.heads))
 764         #   make 'unverified heads' set?
 765         # for each overall head, attempt verification
 766         # if it fails, attempt on parent, and repeat
 767         # if no successful verification because of lack of parents, request parent
 768         bads = set()
 769         for head in set(self.heads) - set(self.verified.heads):
 770             head_height, last = self.get_height_and_last(head)
 771
 772             for share in self.get_chain(head, head_height if last is None else min(5, max(0, head_height - self.net.CHAIN_LENGTH))):
 773                 if self.attempt_verify(share):
 774                     break
 775                 if share.hash in self.heads:
 776                     bads.add(share.hash)
 777             else:
 778                 if last is not None:
 779                     desired.add((
 780                         self.items[random.choice(list(self.reverse[last]))].peer_addr,
 781                         last,
 782                         max(x.timestamp for x in self.get_chain(head, min(head_height, 5))),
 783                         min(x.target for x in self.get_chain(head, min(head_height, 5))),
 784                     ))
 785         for bad in bads:
 786             assert bad not in self.verified.items
 787             assert bad in self.heads
 788             if p2pool.DEBUG:
 789                 print "BAD", bad
 790             self.remove(bad)
 791
 792         # try to get at least CHAIN_LENGTH height for each verified head, requesting parents if needed
 793         for head in list(self.verified.heads):
 794             head_height, last_hash = self.verified.get_height_and_last(head)
 795             last_height, last_last_hash = self.get_height_and_last(last_hash)
 796             # XXX review boundary conditions
 797             want = max(self.net.CHAIN_LENGTH - head_height, 0)
 798             can = max(last_height - 1 - self.net.CHAIN_LENGTH, 0) if last_last_hash is not None else last_height
 799             get = min(want, can)
 800             #print 'Z', head_height, last_hash is None, last_height, last_last_hash is None, want, can, get
 801             for share in self.get_chain(last_hash, get):
 802                 if not self.attempt_verify(share):
 803                     break
 804             if head_height < self.net.CHAIN_LENGTH and last_last_hash is not None:
 805                 desired.add((
 806                     self.items[random.choice(list(self.verified.reverse[last_hash]))].peer_addr,
 807                     last_last_hash,
 808                     max(x.timestamp for x in self.get_chain(head, min(head_height, 5))),
 809                     min(x.target for x in self.get_chain(head, min(head_height, 5))),
 810                 ))
 811
 812         # decide best tree
 813         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)
 814         if p2pool.DEBUG:
 815             print len(decorated_tails), 'tails:'
 816             for score, tail_hash in decorated_tails:
 817                 print format_hash(tail_hash), score
 818         best_tail_score, best_tail = decorated_tails[-1] if decorated_tails else (None, None)
 819
 820         # decide best verified head
 821         decorated_heads = sorted(((
 822             self.verified.get_work(self.verified.get_nth_parent_hash(h, min(5, self.verified.get_height(h)))),
 823             #self.items[h].peer_addr is None,
 824             -self.items[h].should_punish_reason(previous_block, bits, self, known_txs)[0],
 825             -self.items[h].time_seen,
 826         ), h) for h in self.verified.tails.get(best_tail, []))
 827         if p2pool.DEBUG:
 828             print len(decorated_heads), 'heads. Top 10:'
 829             for score, head_hash in decorated_heads[-10:]:
 830                 print '   ', format_hash(head_hash), format_hash(self.items[head_hash].previous_hash), score
 831         best_head_score, best = decorated_heads[-1] if decorated_heads else (None, None)
 832
 833         if best is not None:
 834             best_share = self.items[best]
 835             punish, punish_reason = best_share.should_punish_reason(previous_block, bits, self, known_txs)
 836             if punish > 0:
 837                 print 'Punishing share for %r! Jumping from %s to %s!' % (punish_reason, format_hash(best), format_hash(best_share.previous_hash))
 838                 best = best_share.previous_hash
 839
 840             timestamp_cutoff = min(int(time.time()), best_share.timestamp) - 3600
 841             target_cutoff = int(2**256//(self.net.SHARE_PERIOD*best_tail_score[1] + 1) * 2 + .5) if best_tail_score[1] is not None else 2**256-1
 842         else:
 843             timestamp_cutoff = int(time.time()) - 24*60*60
 844             target_cutoff = 2**256-1
 845
 846         if p2pool.DEBUG:
 847             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))
 848             for peer_addr, hash, ts, targ in desired:
 849                 print '   ', None if peer_addr is None else '%s:%i' % peer_addr, format_hash(hash), math.format_dt(time.time() - ts), bitcoin_data.target_to_difficulty(targ), ts >= timestamp_cutoff, targ <= target_cutoff
 850
 851         return best, [(peer_addr, hash) for peer_addr, hash, ts, targ in desired if ts >= timestamp_cutoff], decorated_heads
 852
 853     def score(self, share_hash, block_rel_height_func):
 854         # returns approximate lower bound on chain's hashrate in the last self.net.CHAIN_LENGTH*15//16*self.net.SHARE_PERIOD time
 855
 856         head_height = self.verified.get_height(share_hash)
 857         if head_height < self.net.CHAIN_LENGTH:
 858             return head_height, None
 859
 860         end_point = self.verified.get_nth_parent_hash(share_hash, self.net.CHAIN_LENGTH*15//16)
 861
 862         block_height = max(block_rel_height_func(share.header['previous_block']) for share in
 863             self.verified.get_chain(end_point, self.net.CHAIN_LENGTH//16))
 864
 865         return self.net.CHAIN_LENGTH, self.verified.get_delta(share_hash, end_point).work/((0 - block_height + 1)*self.net.PARENT.BLOCK_PERIOD)
 866
 867 def get_pool_attempts_per_second(tracker, previous_share_hash, dist, min_work=False, integer=False):
 868     assert dist >= 2
 869     near = tracker.items[previous_share_hash]
 870     far = tracker.items[tracker.get_nth_parent_hash(previous_share_hash, dist - 1)]
 871     attempts = tracker.get_delta(near.hash, far.hash).work if not min_work else tracker.get_delta(near.hash, far.hash).min_work
 872     time = near.timestamp - far.timestamp
 873     if time <= 0:
 874         time = 1
 875     if integer:
 876         return attempts//time
 877     return attempts/time
 878
 879 def get_average_stale_prop(tracker, share_hash, lookbehind):
 880     stales = sum(1 for share in tracker.get_chain(share_hash, lookbehind) if share.share_data['stale_info'] is not None)
 881     return stales/(lookbehind + stales)
 882
 883 def get_stale_counts(tracker, share_hash, lookbehind, rates=False):
 884     res = {}
 885     for share in tracker.get_chain(share_hash, lookbehind - 1):
 886         res['good'] = res.get('good', 0) + bitcoin_data.target_to_average_attempts(share.target)
 887         s = share.share_data['stale_info']
 888         if s is not None:
 889             res[s] = res.get(s, 0) + bitcoin_data.target_to_average_attempts(share.target)
 890     if rates:
 891         dt = tracker.items[share_hash].timestamp - tracker.items[tracker.get_nth_parent_hash(share_hash, lookbehind - 1)].timestamp
 892         res = dict((k, v/dt) for k, v in res.iteritems())
 893     return res
 894
 895 def get_user_stale_props(tracker, share_hash, lookbehind):
 896     res = {}
 897     for share in tracker.get_chain(share_hash, lookbehind - 1):
 898         stale, total = res.get(share.share_data['pubkey_hash'], (0, 0))
 899         total += 1
 900         if share.share_data['stale_info'] is not None:
 901             stale += 1
 902             total += 1
 903         res[share.share_data['pubkey_hash']] = stale, total
 904     return dict((pubkey_hash, stale/total) for pubkey_hash, (stale, total) in res.iteritems())
 905
 906 def get_expected_payouts(tracker, best_share_hash, block_target, subsidy, net):
 907     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))
 908     res = dict((script, subsidy*weight//total_weight) for script, weight in weights.iteritems())
 909     res[DONATION_SCRIPT] = res.get(DONATION_SCRIPT, 0) + subsidy - sum(res.itervalues())
 910     return res
 911
 912 def get_desired_version_counts(tracker, best_share_hash, dist):
 913     res = {}
 914     for share in tracker.get_chain(best_share_hash, dist):
 915         res[share.desired_version] = res.get(share.desired_version, 0) + bitcoin_data.target_to_average_attempts(share.target)
 916     return res
 917
 918 def get_warnings(tracker, best_share, net, bitcoind_warning, bitcoind_work_value):
 919     res = []
 920
 921     desired_version_counts = get_desired_version_counts(tracker, best_share,
 922         min(net.CHAIN_LENGTH, 60*60//net.SHARE_PERIOD, tracker.get_height(best_share)))
 923     majority_desired_version = max(desired_version_counts, key=lambda k: desired_version_counts[k])
 924     if majority_desired_version > (Share.SUCCESSOR if Share.SUCCESSOR is not None else Share).VOTING_VERSION and desired_version_counts[majority_desired_version] > sum(desired_version_counts.itervalues())/2:
 925         res.append('A MAJORITY OF SHARES CONTAIN A VOTE FOR AN UNSUPPORTED SHARE IMPLEMENTATION! (v%i with %i%% support)\n'
 926             'An upgrade is likely necessary. Check http://p2pool.forre.st/ for more information.' % (
 927                 majority_desired_version, 100*desired_version_counts[majority_desired_version]/sum(desired_version_counts.itervalues())))
 928
 929     if bitcoind_warning is not None:
 930         if 'This is a pre-release test build' not in bitcoind_warning:
 931             res.append('(from bitcoind) %s' % (bitcoind_warning,))
 932
 933     if time.time() > bitcoind_work_value['last_update'] + 60:
 934         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']),))
 935
 936     return res
 937
 938 def format_hash(x):
 939     if x is None:
 940         return 'xxxxxxxx'
 941     return '%08x' % (x % 2**32)
 942
 943 class ShareStore(object):
 944     def __init__(self, prefix, net):
 945         self.filename = prefix
 946         self.dirname = os.path.dirname(os.path.abspath(prefix))
 947         self.filename = os.path.basename(os.path.abspath(prefix))
 948         self.net = net
 949         self.known = None # will be filename -> set of share hashes, set of verified hashes
 950         self.known_desired = None
 951
 952     def get_shares(self):
 953         if self.known is not None:
 954             raise AssertionError()
 955         known = {}
 956         filenames, next = self.get_filenames_and_next()
 957         for filename in filenames:
 958             share_hashes, verified_hashes = known.setdefault(filename, (set(), set()))
 959             with open(filename, 'rb') as f:
 960                 for line in f:
 961                     try:
 962                         type_id_str, data_hex = line.strip().split(' ')
 963                         type_id = int(type_id_str)
 964                         if type_id == 0:
 965                             pass
 966                         elif type_id == 1:
 967                             pass
 968                         elif type_id == 2:
 969                             verified_hash = int(data_hex, 16)
 970                             yield 'verified_hash', verified_hash
 971                             verified_hashes.add(verified_hash)
 972                         elif type_id == 5:
 973                             raw_share = share_type.unpack(data_hex.decode('hex'))
 974                             if raw_share['type'] in [0, 1, 2, 3, 4, 5, 6, 7, 8]:
 975                                 continue
 976                             share = load_share(raw_share, self.net, None)
 977                             yield 'share', share
 978                             share_hashes.add(share.hash)
 979                         else:
 980                             raise NotImplementedError("share type %i" % (type_id,))
 981                     except Exception:
 982                         log.err(None, "HARMLESS error while reading saved shares, continuing where left off:")
 983         self.known = known
 984         self.known_desired = dict((k, (set(a), set(b))) for k, (a, b) in known.iteritems())
 985
 986     def _add_line(self, line):
 987         filenames, next = self.get_filenames_and_next()
 988         if filenames and os.path.getsize(filenames[-1]) < 10e6:
 989             filename = filenames[-1]
 990         else:
 991             filename = next
 992
 993         with open(filename, 'ab') as f:
 994             f.write(line + '\n')
 995
 996         return filename
 997
 998     def add_share(self, share):
 999         for filename, (share_hashes, verified_hashes) in self.known.iteritems():
1000             if share.hash in share_hashes:
1001                 break
1002         else:
1003             filename = self._add_line("%i %s" % (5, share_type.pack(share.as_share()).encode('hex')))
1004             share_hashes, verified_hashes = self.known.setdefault(filename, (set(), set()))
1005             share_hashes.add(share.hash)
1006         share_hashes, verified_hashes = self.known_desired.setdefault(filename, (set(), set()))
1007         share_hashes.add(share.hash)
1008
1009     def add_verified_hash(self, share_hash):
1010         for filename, (share_hashes, verified_hashes) in self.known.iteritems():
1011             if share_hash in verified_hashes:
1012                 break
1013         else:
1014             filename = self._add_line("%i %x" % (2, share_hash))
1015             share_hashes, verified_hashes = self.known.setdefault(filename, (set(), set()))
1016             verified_hashes.add(share_hash)
1017         share_hashes, verified_hashes = self.known_desired.setdefault(filename, (set(), set()))
1018         verified_hashes.add(share_hash)
1019
1020     def get_filenames_and_next(self):
1021         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())
1022         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)))
1023
1024     def forget_share(self, share_hash):
1025         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
1026             if share_hash in share_hashes:
1027                 share_hashes.remove(share_hash)
1028         self.check_remove()
1029
1030     def forget_verified_share(self, share_hash):
1031         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
1032             if share_hash in verified_hashes:
1033                 verified_hashes.remove(share_hash)
1034         self.check_remove()
1035
1036     def check_remove(self):
1037         to_remove = set()
1038         for filename, (share_hashes, verified_hashes) in self.known_desired.iteritems():
1039             #print filename, len(share_hashes) + len(verified_hashes)
1040             if not share_hashes and not verified_hashes:
1041                 to_remove.add(filename)
1042         for filename in to_remove:
1043             self.known.pop(filename)
1044             self.known_desired.pop(filename)
1045             os.remove(filename)
1046             print "REMOVED", filename