1 from __future__ import division
7 from twisted.internet import defer
8 from twisted.python import log
11 from p2pool import skiplists
12 from p2pool.bitcoin import data as bitcoin_data, script
13 from p2pool.util import memoize, expiring_dict, math, deferral
16 merkle_branch_type = bitcoin_data.ListType(bitcoin_data.ComposedType([
17 ('side', bitcoin_data.StructType('<B')), # enum?
18 ('hash', bitcoin_data.HashType()),
22 share_data_type = bitcoin_data.ComposedType([
23 ('previous_share_hash', bitcoin_data.PossiblyNone(0, bitcoin_data.HashType())),
24 ('target', bitcoin_data.FloatingIntegerType()),
25 ('nonce', bitcoin_data.VarStrType()),
29 coinbase_type = bitcoin_data.ComposedType([
30 ('identifier', bitcoin_data.FixedStrType(8)),
31 ('share_data', share_data_type),
34 share_info_type = bitcoin_data.ComposedType([
35 ('share_data', share_data_type),
36 ('new_script', bitcoin_data.VarStrType()),
37 ('subsidy', bitcoin_data.StructType('<Q')),
41 share1a_type = bitcoin_data.ComposedType([
42 ('header', bitcoin_data.block_header_type),
43 ('share_info', share_info_type),
44 ('merkle_branch', merkle_branch_type),
47 share1b_type = bitcoin_data.ComposedType([
48 ('header', bitcoin_data.block_header_type),
49 ('share_info', share_info_type),
50 ('other_txs', bitcoin_data.ListType(bitcoin_data.tx_type)),
53 def calculate_merkle_branch(txs, index):
54 hash_list = [(bitcoin_data.tx_type.hash256(tx), i == index, []) for i, tx in enumerate(txs)]
56 while len(hash_list) > 1:
59 bitcoin_data.merkle_record_type.hash256(dict(left=left, right=right)),
61 (left_l if left_f else right_l) + [dict(side=1, hash=right) if left_f else dict(side=0, hash=left)],
63 for (left, left_f, left_l), (right, right_f, right_l) in
64 zip(hash_list[::2], hash_list[1::2] + [hash_list[::2][-1]])
67 assert hash_list[0][1]
68 assert check_merkle_branch(txs[index], hash_list[0][2]) == hash_list[0][0]
70 return hash_list[0][2]
72 def check_merkle_branch(tx, branch):
73 hash_ = bitcoin_data.tx_type.hash256(tx)
76 hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=step['hash'], right=hash_))
78 hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=hash_, right=step['hash']))
81 def gentx_to_share_info(gentx):
83 share_data=coinbase_type.unpack(gentx['tx_ins'][0]['script'])['share_data'],
84 subsidy=sum(tx_out['value'] for tx_out in gentx['tx_outs']),
85 new_script=gentx['tx_outs'][-1]['script'],
88 def share_info_to_gentx(share_info, block_target, tracker, net):
89 return generate_transaction(
91 previous_share_hash=share_info['share_data']['previous_share_hash'],
92 new_script=share_info['new_script'],
93 subsidy=share_info['subsidy'],
94 nonce=share_info['share_data']['nonce'],
95 block_target=block_target,
101 def from_block(cls, block):
102 return cls(block['header'], gentx_to_share_info(block['txs'][0]), other_txs=block['txs'][1:])
105 def from_share1a(cls, share1a):
106 return cls(**share1a)
109 def from_share1b(cls, share1b):
110 return cls(**share1b)
112 __slots__ = 'header previous_block share_info merkle_branch other_txs timestamp share_data new_script subsidy previous_hash previous_share_hash target nonce bitcoin_hash hash time_seen shared peer'.split(' ')
114 def __init__(self, header, share_info, merkle_branch=None, other_txs=None):
115 if merkle_branch is None and other_txs is None:
116 raise ValueError('need either merkle_branch or other_txs')
117 if other_txs is not None:
118 new_merkle_branch = calculate_merkle_branch([dict(version=0, tx_ins=[], tx_outs=[], lock_time=0)] + other_txs, 0)
119 if merkle_branch is not None:
120 if merke_branch != new_merkle_branch:
121 raise ValueError('invalid merkle_branch and other_txs')
122 merkle_branch = new_merkle_branch
124 if len(merkle_branch) > 16:
125 raise ValueError('merkle_branch too long!')
128 self.previous_block = header['previous_block']
129 self.share_info = share_info
130 self.merkle_branch = merkle_branch
131 self.other_txs = other_txs
133 self.timestamp = self.header['timestamp']
135 self.share_data = self.share_info['share_data']
136 self.new_script = self.share_info['new_script']
137 self.subsidy = self.share_info['subsidy']
139 if len(self.new_script) > 100:
140 raise ValueError('new_script too long!')
142 self.previous_hash = self.previous_share_hash = self.share_data['previous_share_hash']
143 self.target = self.share_data['target']
144 self.nonce = self.share_data['nonce']
146 if len(self.nonce) > 100:
147 raise ValueError('nonce too long!')
149 self.bitcoin_hash = bitcoin_data.block_header_type.hash256(header)
150 self.hash = share1a_type.hash256(self.as_share1a())
152 if self.bitcoin_hash > self.target:
153 print 'hash', hex(self.bitcoin_hash)
154 print 'targ', hex(self.target)
155 raise ValueError('not enough work!')
157 if script.get_sigop_count(self.new_script) > 1:
158 raise ValueError('too many sigops!')
161 self.time_seen = time.time()
165 def as_block(self, tracker, net):
166 if self.other_txs is None:
167 raise ValueError('share does not contain all txs')
169 gentx = share_info_to_gentx(self.share_info, self.header['target'], tracker, net)
171 return dict(header=self.header, txs=[gentx] + self.other_txs)
173 def as_share1a(self):
174 return dict(header=self.header, share_info=self.share_info, merkle_branch=self.merkle_branch)
176 def as_share1b(self):
177 return dict(header=self.header, share_info=self.share_info, other_txs=self.other_txs)
179 def check(self, tracker, now, net):
181 if self.previous_share_hash is not None:
182 if self.header['timestamp'] <= math.median((s.timestamp for s in itertools.islice(tracker.get_chain_to_root(self.previous_share_hash), 11)), use_float=False):
183 raise ValueError('share from too far in the past!')
185 if self.header['timestamp'] > now + 2*60*60:
186 raise ValueError('share from too far in the future!')
188 gentx = share_info_to_gentx(self.share_info, self.header['target'], tracker, net)
190 if len(gentx['tx_ins'][0]['script']) > 100:
191 raise ValueError('''coinbase too large!''')
193 if check_merkle_branch(gentx, self.merkle_branch) != self.header['merkle_root']:
194 raise ValueError('''gentx doesn't match header via merkle_branch''')
196 if self.other_txs is not None:
197 if bitcoin_data.merkle_hash([gentx] + self.other_txs) != self.header['merkle_root']:
198 raise ValueError('''gentx doesn't match header via other_txs''')
200 if len(bitcoin_data.block_type.pack(dict(header=self.header, txs=[gentx] + self.other_txs))) > 1000000 - 1000:
201 raise ValueError('''block size too large''')
203 def flag_shared(self):
207 return '<Share %s>' % (' '.join('%s=%r' % (k, v) for k, v in self.__dict__.iteritems()),)
209 def get_pool_attempts_per_second(tracker, previous_share_hash, net, dist=None):
211 dist = net.TARGET_LOOKBEHIND
212 near = tracker.shares[previous_share_hash]
213 far = tracker.shares[tracker.get_nth_parent_hash(previous_share_hash, dist - 1)]
214 attempts = tracker.get_work(near.hash) - tracker.get_work(far.hash)
215 time = near.timestamp - far.timestamp
218 return attempts//time
220 def generate_transaction(tracker, previous_share_hash, new_script, subsidy, nonce, block_target, net):
221 height, last = tracker.get_height_and_last(previous_share_hash)
222 if height < net.TARGET_LOOKBEHIND:
223 target = bitcoin_data.FloatingIntegerType().truncate_to(2**256//2**20 - 1)
225 attempts_per_second = get_pool_attempts_per_second(tracker, previous_share_hash, net)
226 pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1
227 previous_share = tracker.shares[previous_share_hash] if previous_share_hash is not None else None
228 pre_target2 = math.clip(pre_target, (previous_share.target*9//10, previous_share.target*11//10))
229 pre_target3 = math.clip(pre_target2, (0, net.MAX_TARGET))
230 target = bitcoin_data.FloatingIntegerType().truncate_to(pre_target3)
232 attempts_to_block = bitcoin_data.target_to_average_attempts(block_target)
233 max_weight = net.SPREAD * attempts_to_block
236 class fake_share(object):
238 fake_share.new_script = new_script
239 fake_share.target = target
243 for share in itertools.chain([fake_share], itertools.islice(tracker.get_chain_to_root(previous_share_hash), net.CHAIN_LENGTH)):
244 weight = bitcoin_data.target_to_average_attempts(share.target)
245 if weight > max_weight - total_weight:
246 weight = max_weight - total_weight
248 dest_weights[share.new_script] = dest_weights.get(share.new_script, 0) + weight
249 total_weight += weight
251 if total_weight == max_weight:
255 this_weight = min(bitcoin_data.target_to_average_attempts(target), max_weight)
256 other_weights, other_weights_total = tracker.get_cumulative_weights(previous_share_hash, min(height, net.CHAIN_LENGTH), max(0, max_weight - this_weight))
257 dest_weights, total_weight = math.add_dicts([{new_script: this_weight}, other_weights]), this_weight + other_weights_total
258 total_weight = sum(dest_weights.itervalues())
260 amounts = dict((script, subsidy*(396*weight)//(400*total_weight)) for (script, weight) in dest_weights.iteritems())
261 amounts[new_script] = amounts.get(new_script, 0) + subsidy*2//400
262 amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy*2//400
263 amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy - sum(amounts.itervalues()) # collect any extra
264 if sum(amounts.itervalues()) != subsidy:
266 if any(x < 0 for x in amounts.itervalues()):
269 pre_dests = sorted(amounts.iterkeys(), key=lambda script: (amounts[script], script))
270 pre_dests = pre_dests[-4000:] # block length limit, unlikely to ever be hit
272 dests = sorted(pre_dests, key=lambda script: (script == new_script, script))
273 assert dests[-1] == new_script
278 previous_output=None,
280 script=coinbase_type.pack(dict(
281 identifier=net.IDENTIFIER,
283 previous_share_hash=previous_share_hash,
289 tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script]],
295 class OkayTracker(bitcoin_data.Tracker):
296 def __init__(self, net):
297 bitcoin_data.Tracker.__init__(self)
299 self.verified = bitcoin_data.Tracker()
301 self.get_cumulative_weights = skiplists.WeightsSkipList(self)
303 def attempt_verify(self, share, now):
304 if share.hash in self.verified.shares:
306 height, last = self.get_height_and_last(share.hash)
307 if height < self.net.CHAIN_LENGTH and last is not None:
308 raise AssertionError()
310 share.check(self, now, self.net)
312 log.err(None, 'Share check failed:')
315 self.verified.add(share)
318 def think(self, ht, previous_block, now):
322 # make 'unverified heads' set?
323 # for each overall head, attempt verification
324 # if it fails, attempt on parent, and repeat
325 # if no successful verification because of lack of parents, request parent
327 for head in set(self.heads) - set(self.verified.heads):
328 head_height, last = self.get_height_and_last(head)
330 for share in itertools.islice(self.get_chain_known(head), None if last is None else min(5, max(0, head_height - self.net.CHAIN_LENGTH))):
331 if self.attempt_verify(share, now):
333 if share.hash in self.heads:
337 desired.add((self.shares[random.choice(list(self.reverse_shares[last]))].peer, last))
339 assert bad not in self.verified.shares
340 assert bad in self.heads
343 # try to get at least CHAIN_LENGTH height for each verified head, requesting parents if needed
344 for head in list(self.verified.heads):
345 head_height, last_hash = self.verified.get_height_and_last(head)
346 last_height, last_last_hash = self.get_height_and_last(last_hash)
347 # XXX review boundary conditions
348 want = max(self.net.CHAIN_LENGTH - head_height, 0)
349 can = max(last_height - 1 - self.net.CHAIN_LENGTH, 0) if last_last_hash is not None else last_height
351 #print 'Z', head_height, last_hash is None, last_height, last_last_hash is None, want, can, get
352 for share in itertools.islice(self.get_chain_known(last_hash), get):
353 if not self.attempt_verify(share, now):
355 if head_height < self.net.CHAIN_LENGTH and last_last_hash is not None:
356 desired.add((self.verified.shares[random.choice(list(self.verified.reverse_shares[last_hash]))].peer, last_last_hash))
359 best_tail = max(self.verified.tails, key=lambda h: self.score(max(self.verified.tails[h], key=self.verified.get_height), ht)) if self.verified.tails else None
360 # decide best verified head
361 scores = sorted(self.verified.tails.get(best_tail, []), key=lambda h: (
362 self.verified.get_work(self.verified.get_nth_parent_hash(h, min(5, self.verified.get_height(h)))),
363 ht.get_min_height(self.verified.shares[h].previous_block),
364 self.verified.shares[h].peer is None,
365 -self.verified.shares[h].time_seen
370 print len(self.verified.tails.get(best_tail, []))
372 print ' ', format_hash(h), format_hash(self.verified.shares[h].previous_hash), (
373 self.verified.get_work(self.verified.get_nth_parent_hash(h, min(5, self.verified.get_height(h)))),
374 ht.get_min_height(self.verified.shares[h].previous_block),
375 self.verified.shares[h].peer is None,
376 -self.verified.shares[h].time_seen
382 for share_hash in list(self.heads):
383 if share_hash in scores[-5:]:
385 if self.shares[share_hash].time_seen > time.time() - 30:
387 self.remove(share_hash)
388 if share_hash in self.verified.shares:
389 self.verified.remove(share_hash)
397 # if removed from this, it must be removed from verified
398 for tail, heads in list(self.tails.iteritems()):
399 if min(self.get_height(head) for head in heads) < 2*self.net.CHAIN_LENGTH + 10:
402 for aftertail in list(self.reverse_shares.get(tail, set())):
403 self.remove(aftertail)
404 if tail in self.verified.shares:
405 self.verified.remove(aftertail)
408 print "removed! %x %f" % (tail, end - start)
412 best = scores[-1] if scores else None
415 best_share = self.verified.shares[best]
416 if ht.get_min_height(best_share.header['previous_block']) < ht.get_min_height(previous_block) and best_share.bitcoin_hash != previous_block and best_share.peer is not None:
418 print 'Stale detected!'
419 best = best_share.previous_hash
423 @memoize.memoize_with_backing(expiring_dict.ExpiringDict(5, get_touches=False))
424 def score(self, share_hash, ht):
425 head_height, last = self.verified.get_height_and_last(share_hash)
429 # XXX should only look past a certain share, not at recent ones
430 share2_hash = self.verified.get_nth_parent_hash(share_hash, min(self.net.CHAIN_LENGTH//2, head_height//2)) if last is not None else share_hash
431 # XXX this must go in the opposite direction for max_height to make sense
432 for share in reversed(list(itertools.islice(self.verified.get_chain_known(share2_hash), self.net.CHAIN_LENGTH))):
433 max_height = max(max_height, ht.get_min_height(share.header['previous_block']))
434 attempts += bitcoin_data.target_to_average_attempts(share.target)
435 this_score = attempts//(ht.get_highest_height() - max_height + 1)
436 if this_score > score2:
438 return min(head_height, self.net.CHAIN_LENGTH), score2
443 return '%08x' % (x % 2**32)
445 class Mainnet(bitcoin_data.Mainnet):
446 SHARE_PERIOD = 5 # seconds
447 CHAIN_LENGTH = 24*60*60//5 # shares
448 TARGET_LOOKBEHIND = 200 # shares
450 SCRIPT = '4104ffd03de44a6e11b9917f3a29f9443283d9871c9d743ef30d5eddcd37094b64d1b3d8090496b53256786bf5c82932ec23c3b74d9f05a6f95a8b5529352656664bac'.decode('hex')
451 IDENTIFIER = 'fc70035c7a81bc6f'.decode('hex')
452 PREFIX = '2472ef181efcd37b'.decode('hex')
453 ADDRS_TABLE = 'addrs'
455 MAX_TARGET = 2**256//2**32 - 1
458 class Testnet(bitcoin_data.Testnet):
459 SHARE_PERIOD = 1 # seconds
460 CHAIN_LENGTH = 24*60*60//5 # shares
461 TARGET_LOOKBEHIND = 200 # shares
463 SCRIPT = '410403ad3dee8ab3d8a9ce5dd2abfbe7364ccd9413df1d279bf1a207849310465b0956e5904b1155ecd17574778f9949589ebfd4fb33ce837c241474a225cf08d85dac'.decode('hex')
464 IDENTIFIER = '5fc2be2d4f0d6bfb'.decode('hex')
465 PREFIX = '3f6057a15036f441'.decode('hex')
466 ADDRS_TABLE = 'addrs_testnet'
468 MAX_TARGET = 2**256//2**20 - 1