skip list implementation
[p2pool.git] / p2pool / data.py
1 from __future__ import division
2
3 import itertools
4 import random
5
6 from twisted.python import log
7
8 from p2pool.util import math
9 from p2pool.bitcoin import data as bitcoin_data
10
11 class CompressedList(bitcoin_data.Type):
12     def __init__(self, inner):
13         self.inner = inner
14     
15     def read(self, file):
16         values, file = bitcoin_data.ListType(self.inner).read(file)
17         if values != sorted(set(values)):
18             raise ValueError("invalid values")
19         references, file = bitcoin_data.ListType(bitcoin_data.VarIntType()).read(file)
20         return [values[reference] for reference in references], file
21     
22     def write(self, file, item):
23         values = sorted(set(item))
24         values_map = dict((value, i) for i, value in enumerate(values))
25         file = bitcoin_data.ListType(self.inner).write(file, values)
26         return bitcoin_data.ListType(bitcoin_data.VarIntType()).write(file, [values_map[subitem] for subitem in item])
27
28
29 merkle_branch_type = bitcoin_data.ListType(bitcoin_data.ComposedType([
30     ('side', bitcoin_data.StructType('<B')), # enum?
31     ('hash', bitcoin_data.HashType()),
32 ]))
33
34
35 share_data_type = bitcoin_data.ComposedType([
36     ('previous_share_hash', bitcoin_data.PossiblyNone(0, bitcoin_data.HashType())),
37     ('previous_shares_hash', bitcoin_data.HashType()),
38     ('target2', bitcoin_data.FloatingIntegerType()),
39     ('nonce', bitcoin_data.VarStrType()),
40 ])
41
42
43 coinbase_type = bitcoin_data.ComposedType([
44     ('identifier', bitcoin_data.FixedStrType(8)),
45     ('share_data', share_data_type),
46 ])
47
48 share_info_type = bitcoin_data.ComposedType([
49     ('share_data', share_data_type),
50     ('new_script', bitcoin_data.VarStrType()),
51     ('subsidy', bitcoin_data.StructType('<Q')),
52 ])
53
54
55 share1a_type = bitcoin_data.ComposedType([
56     ('header', bitcoin_data.block_header_type), # merkle_header not completely needed
57     ('share_info', share_info_type),
58     ('merkle_branch', merkle_branch_type),
59 ])
60
61 share1b_type = bitcoin_data.ComposedType([
62     ('header', bitcoin_data.block_header_type),
63     ('share_info', share_info_type),
64     ('other_txs', bitcoin_data.ListType(bitcoin_data.tx_type)),
65 ])
66
67 shares_type = CompressedList(bitcoin_data.VarStrType())
68
69 def calculate_merkle_branch(txs, index):
70     hash_list = [(bitcoin_data.tx_type.hash256(tx), i == index, []) for i, tx in enumerate(txs)]
71     
72     while len(hash_list) > 1:
73         hash_list = [
74             (
75                 bitcoin_data.merkle_record_type.hash256(dict(left=left, right=right)),
76                 left_f or right_f,
77                 (left_l if left_f else right_l) + [dict(side=1, hash=right) if left_f else dict(side=0, hash=left)],
78             )
79             for (left, left_f, left_l), (right, right_f, right_l) in
80                 zip(hash_list[::2], hash_list[1::2] + [hash_list[::2][-1]])
81         ]
82     
83     assert hash_list[0][1]
84     assert check_merkle_branch(txs[index], hash_list[0][2]) == hash_list[0][0]
85     
86     return hash_list[0][2]
87
88 def check_merkle_branch(tx, branch):
89     hash_ = bitcoin_data.tx_type.hash256(tx)
90     for step in branch:
91         if not step['side']:
92             hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=step['hash'], right=hash_))
93         else:
94             hash_ = bitcoin_data.merkle_record_type.hash256(dict(left=hash_, right=step['hash']))
95     return hash_
96
97 def gentx_to_share_info(gentx):
98     return dict(
99         share_data=coinbase_type.unpack(gentx['tx_ins'][0]['script'])['share_data'],
100         subsidy=sum(tx_out['value'] for tx_out in gentx['tx_outs']),
101         new_script=gentx['tx_outs'][-1]['script'],
102     )
103
104 def share_info_to_gentx(share_info, block_target, tracker, net):
105     return generate_transaction(
106         tracker=tracker,
107         previous_share_hash=share_info['share_data']['previous_share_hash'],
108         new_script=share_info['new_script'],
109         subsidy=share_info['subsidy'],
110         nonce=share_info['share_data']['nonce'],
111         block_target=block_target,
112         net=net,
113     )
114
115 class Share(object):
116     peer = None
117     gentx = None
118     
119     @classmethod
120     def from_block(cls, block):
121         return cls(block['header'], gentx_to_share_info(block['txs'][0]), other_txs=block['txs'][1:])
122     
123     @classmethod
124     def from_share1a(cls, share1a):
125         return cls(**share1a)
126     
127     @classmethod
128     def from_share1b(cls, share1b):
129         return cls(**share1b)
130     
131     def __init__(self, header, share_info, merkle_branch=None, other_txs=None):
132         if merkle_branch is None and other_txs is None:
133             raise ValueError('need either merkle_branch or other_txs')
134         if other_txs is not None:
135             new_merkle_branch = calculate_merkle_branch([dict(version=0, tx_ins=[], tx_outs=[], lock_time=0)] + other_txs, 0)
136             if merkle_branch is not None:
137                 if merke_branch != new_merkle_branch:
138                     raise ValueError('invalid merkle_branch and other_txs')
139             merkle_branch = new_merkle_branch
140         
141         self.header = header
142         self.share_info = share_info
143         self.merkle_branch = merkle_branch
144         self.other_txs = other_txs
145         
146         self.timestamp = self.header['timestamp']
147         
148         self.share_data = self.share_info['share_data']
149         self.new_script = self.share_info['new_script']
150         self.subsidy = self.share_info['subsidy']
151         
152         self.previous_hash = self.previous_share_hash = self.share_data['previous_share_hash']
153         self.previous_shares_hash = self.share_data['previous_shares_hash']
154         self.target2 = self.share_data['target2']
155         
156         self.hash = bitcoin_data.block_header_type.hash256(header)
157         
158         if self.hash > self.target2:
159             print "hash", hex(self.hash)
160             print "targ", hex(self.target2)
161             raise ValueError('not enough work!')
162         
163         
164         self.shared = False
165     
166     def as_block(self):
167         if self.other_txs is None:
168             raise ValueError('share does not contain all txs')
169         
170         return dict(header=self.header, txs=[self.gentx] + self.other_txs)
171     
172     def as_share1a(self):
173         return dict(header=self.header, share_info=self.share_info, merkle_branch=self.merkle_branch)
174     
175     def as_share1b(self):
176         return dict(header=self.header, share_info=self.share_info, other_txs=self.other_txs)
177     
178     def check(self, tracker, net):
179         import time
180         if self.previous_share_hash is not None:
181             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):
182                 raise ValueError('share from too far in the past!')
183         
184         # XXX use adjusted time
185         if self.header['timestamp'] > time.time() + 2*60*60:
186             raise ValueError('share from too far in the future!')
187         
188         gentx = share_info_to_gentx(self.share_info, self.header['target'], tracker, net)
189         
190         if check_merkle_branch(gentx, self.merkle_branch) != self.header['merkle_root']:
191             raise ValueError("gentx doesn't match header via merkle_branch")
192         
193         if self.other_txs is not None:
194             if bitcoin_data.merkle_hash([gentx] + self.other_txs) != self.header['merkle_root']:
195                 raise ValueError("gentx doesn't match header via other_txs")
196         
197         self.gentx = gentx
198         
199         return Share2(self)
200     
201     def flag_shared(self):
202         self.shared = True
203     
204     def __repr__(self):
205         return '<Share %s>' % (' '.join('%s=%r' % (k, v) for k, v in self.__dict__.iteritems()),)
206
207 class Share2(object):
208     '''Share with associated data'''
209     
210     def __init__(self, share):
211         self.share = share
212         
213         self.shared = False
214     
215     def flag_shared(self):
216         self.shared = True
217
218 def generate_transaction(tracker, previous_share_hash, new_script, subsidy, nonce, block_target, net):
219     previous_share2 = tracker.shares[previous_share_hash] if previous_share_hash is not None else None
220     #previous_share2 = chain.shares
221     #previous_shares
222     #shares =
223     #shares = (previous_share2.shares if previous_share2 is not None else [net.SCRIPT]*net.SPREAD)[1:-1] + [new_script, new_script]
224     
225     lookbehind = 200
226     chain = list(itertools.islice(tracker.get_chain_to_root(previous_share_hash), lookbehind))
227     if len(chain) < lookbehind:
228         target2 = bitcoin_data.FloatingIntegerType().truncate_to(2**256//2**24 - 1)
229     else:
230         attempts = sum(bitcoin_data.target_to_average_attempts(share.target2) for share in chain[:-1])
231         time = chain[0].timestamp - chain[-1].timestamp
232         if time == 0:
233             time = 1
234         attempts_per_second = attempts//time
235         pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1
236         pre_target2 = math.clip(pre_target, (previous_share2.target2*9//10, previous_share2.target2*11//10))
237         pre_target3 = math.clip(pre_target2, (0, 2**256//2**24 - 1))
238         target2 = bitcoin_data.FloatingIntegerType().truncate_to(pre_target3)
239         print attempts_per_second//1000, "KHASH"
240         #print "TARGET", 2**256//target2, 2**256/pre_target
241         #print "ATT", bitcoin_data.target_to_average_attempts(target2)//1000
242     
243     
244     attempts_to_block = bitcoin_data.target_to_average_attempts(block_target)
245     max_weight = net.SPREAD * attempts_to_block
246     total_weight = 0
247     
248     class fake_share(object):
249         pass
250     fake_share.new_script = new_script
251     fake_share.target2 = target2
252     
253     dest_weights = {}
254     for i, share in enumerate(itertools.chain([fake_share], itertools.islice(tracker.get_chain_to_root(previous_share_hash), net.CHAIN_LENGTH))):
255         weight = bitcoin_data.target_to_average_attempts(share.target2)
256         if weight > max_weight - total_weight:
257             weight = max_weight - total_weight
258         
259         dest_weights[share.new_script] = dest_weights.get(share.new_script, 0) + weight
260         total_weight += weight
261         
262         if total_weight == max_weight:
263             break
264     
265     amounts = dict((script, subsidy*(199*weight)//(200*total_weight)) for (script, weight) in dest_weights.iteritems())
266     amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy*1//200
267     amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy - sum(amounts.itervalues()) # collect any extra
268     
269     dests = sorted(amounts.iterkeys(), key=lambda script: (script == new_script, script))
270     assert dests[-1] == new_script
271     
272     previous_shares = [] # XXX
273     
274     return dict(
275         version=1,
276         tx_ins=[dict(
277             previous_output=None,
278             sequence=None,
279             script=coinbase_type.pack(dict(
280                 identifier=net.IDENTIFIER,
281                 share_data=dict(
282                     previous_share_hash=previous_share_hash,
283                     previous_shares_hash=shares_type.hash256(previous_shares),
284                     nonce=nonce,
285                     target2=target2,
286                 ),
287             )),
288         )],
289         tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script]],
290         lock_time=0,
291     )
292
293
294
295 class OkayTracker(bitcoin_data.Tracker):
296     def __init__(self, net):
297         bitcoin_data.Tracker.__init__(self)
298         self.net = net
299         self.verified = bitcoin_data.Tracker()
300     """
301         self.okay_cache = {} # hash -> height
302     
303     def is_okay(self, start, _height_after=0):
304         '''
305         Returns:
306             {'result': 'okay', verified_height: ...} # if share has an okay parent or if share has CHAIN_LENGTH children and CHAIN_LENTH parents that it verified with
307             {'result': 'needs_share', 'share_hash': ...} # if share doesn't have CHAIN_LENGTH parents
308             #{'result': 'needs_share_shares', 'share_hash': ...} # if share has CHAIN_LENGTH children and needs its shares to
309             {'result': 'not_okay'} # if the share has a not okay parent or if the share has an okay parent and failed validation
310         '''
311         
312         if start in self.okay_cache:
313             return dict(result='okay', verified_height=self.okay_cache['start'])
314         
315         share = self.shares[start]
316         if start not in self.shares:
317             return dict(result='needs_share', share_hash=start)
318         
319         length = len
320         to_end_rev = []
321         for share in itertools.islice(self.get_chain(start), self.net.CHAIN_LENGTH):
322             if share in self.okay_cache:
323                 return validate(share, to_end_rev[::-1])
324             to_end_rev.append(share)
325         # picking up last share from for loop, ew
326         self.okay_cache.add(share)
327         return validate(share, to_end_rev[::-1])
328     """
329     def attempt_verify(self, share):
330         height, last = self.get_height_and_last(share.hash)
331         if height < self.net.CHAIN_LENGTH and last is not None:
332             raise AssertionError()
333         if share.hash in self.verified.shares:
334             return True
335         try:
336             share.check(self, self.net)
337         except:
338             print
339             print "Share check failed:"
340             log.err()
341             print
342             return False
343         else:
344             self.verified.add(share)
345             return True
346     
347     def think(self, ht):
348         desired = set()
349         
350         # O(len(self.heads))
351         #   make 'unverified heads' set?
352         # for each overall head, attempt verification
353         # if it fails, attempt on parent, and repeat
354         # if no successful verification because of lack of parents, request parent
355         for head in self.heads:
356             head_height, last = self.get_height_and_last(head)
357             
358             for share in itertools.islice(self.get_chain_known(head), None if last is None else head_height - self.net.CHAIN_LENGTH):
359                 if self.attempt_verify(share):
360                     break
361             else:
362                 desired.add((self.shares[random.choice(list(self.reverse_shares[last]))].peer, last))
363         
364         # try to get at least CHAIN_LENGTH height for each verified head, requesting parents if needed
365         for head in self.verified.heads:
366             head_height, last_hash = self.verified.get_height_and_last(head)
367             last_height, last_last_hash = self.get_height_and_last(last_hash)
368             # XXX review boundary conditions
369             want = self.net.CHAIN_LENGTH - head_height
370             can = max(last_height - 1 - self.net.CHAIN_LENGTH, 0) if last_last_hash is not None else last_height
371             if want > can:
372                 get = can
373             else:
374                 get = want
375             #print "Z", head_height, last_hash is None, last_height, last_last_hash is None, want, can, get
376             for share in itertools.islice(self.get_chain_known(last_hash), get):
377                 if not self.attempt_verify(share):
378                     break
379             if head_height < self.net.CHAIN_LENGTH and last_last_hash is not None:
380                 desired.add((self.verified.shares[random.choice(list(self.verified.reverse_shares[last_hash]))].peer, last_last_hash))
381         
382         # decide best verified head
383         def score(share_hash):
384             head_height, last = self.verified.get_height_and_last(share_hash)
385             score2 = 0
386             attempts = 0
387             max_height = 0
388             # XXX should only look past a certain share, not at recent ones
389             share2_hash = self.verified.get_nth_parent(share_hash, self.net.CHAIN_LENGTH//2)
390             for share in itertools.islice(self.verified.get_chain_known(share2_hash), self.net.CHAIN_LENGTH):
391                 max_height = max(max_height, ht.get_min_height(share.header['previous_block']))
392                 attempts += bitcoin_data.target_to_average_attempts(share.target2)
393                 this_score = attempts//(ht.get_highest_height() - max_height + 1)
394                 if this_score > score2:
395                     score2 = this_score
396             res = (min(head_height, self.net.CHAIN_LENGTH), score2)
397             print res
398             return res
399         best = max(self.verified.heads, key=score) if self.verified.heads else None
400         
401         return best, desired
402
403
404 class Mainnet(bitcoin_data.Mainnet):
405     SHARE_PERIOD = 5 # seconds
406     CHAIN_LENGTH = 24*60*60//5 # shares
407     SPREAD = 3 # blocks
408     SCRIPT = '4104ffd03de44a6e11b9917f3a29f9443283d9871c9d743ef30d5eddcd37094b64d1b3d8090496b53256786bf5c82932ec23c3b74d9f05a6f95a8b5529352656664bac'.decode('hex')
409     IDENTIFIER = '7452839666e1f8f8'.decode('hex')
410     PREFIX = '2d4224bf18c87b87'.decode('hex')
411     ADDRS_TABLE = 'addrs'
412     P2P_PORT = 9333
413
414 class Testnet(bitcoin_data.Testnet):
415     SHARE_PERIOD = 5 # seconds
416     CHAIN_LENGTH = 24*60*60//5 # shares
417     SPREAD = 3 # blocks
418     SCRIPT = '410403ad3dee8ab3d8a9ce5dd2abfbe7364ccd9413df1d279bf1a207849310465b0956e5904b1155ecd17574778f9949589ebfd4fb33ce837c241474a225cf08d85dac'.decode('hex')
419     IDENTIFIER = '1ae3479e4eb6700a'.decode('hex')
420     PREFIX = 'd19778c812754854'.decode('hex')
421     ADDRS_TABLE = 'addrs_testnet'
422     P2P_PORT = 19333