p2pool/bitcoin/getwork.py

   1 '''
   2 Representation of a getwork request/reply
   3 '''
   4
   5 from __future__ import division
   6
   7 from . import data as bitcoin_data
   8 from . import sha256
   9
  10 def _swap4(s):
  11     if len(s) % 4:
  12         raise ValueError()
  13     return ''.join(s[x:x+4][::-1] for x in xrange(0, len(s), 4))
  14
  15 class BlockAttempt(object):
  16     def __init__(self, version, previous_block, merkle_root, timestamp, block_target, share_target):
  17         self.version, self.previous_block, self.merkle_root, self.timestamp, self.block_target, self.share_target = version, previous_block, merkle_root, timestamp, block_target, share_target
  18
  19     def __hash__(self):
  20         return hash((self.version, self.previous_block, self.merkle_root, self.timestamp, self.block_target, self.share_target))
  21
  22     def __eq__(self, other):
  23         if not isinstance(other, BlockAttempt):
  24             raise ValueError('comparisons only valid with other BlockAttempts')
  25         return self.__dict__ == other.__dict__
  26
  27     def __ne__(self, other):
  28         return not (self == other)
  29
  30     def __repr__(self):
  31         return 'BlockAttempt(%s)' % (', '.join('%s=%r' % (k, v) for k, v in self.__dict__.iteritems()),)
  32
  33     def getwork(self, _check=False, **extra):
  34         if 'data' in extra or 'hash1' in extra or 'target' in extra or 'midstate' in extra:
  35             raise ValueError()
  36
  37         block_data = bitcoin_data.block_header_type.pack(dict(
  38             version=self.version,
  39             previous_block=self.previous_block,
  40             merkle_root=self.merkle_root,
  41             timestamp=self.timestamp,
  42             target=self.block_target,
  43             nonce=0,
  44         ))
  45
  46         getwork = {
  47             'data': _swap4(block_data).encode('hex') + '000000800000000000000000000000000000000000000000000000000000000000000000000000000000000080020000',
  48             'hash1': '00000000000000000000000000000000000000000000000000000000000000000000008000000000000000000000000000000000000000000000000000010000',
  49             'target': bitcoin_data.HashType().pack(self.share_target).encode('hex'),
  50             'midstate': _swap4(sha256.process(block_data[:64])).encode('hex'),
  51         }
  52
  53         if _check:
  54             self_check = self.__class__.from_getwork(getwork, _check=False)
  55             if self_check != self:
  56                 raise AssertionError('failed check - input invalid or implementation error')
  57
  58         getwork = dict(getwork)
  59         getwork.update(extra)
  60
  61         return getwork
  62
  63     @classmethod
  64     def from_getwork(cls, getwork, _check=True):
  65         attrs = decode_data(getwork['data'])
  66
  67         ba = cls(
  68             version=attrs['version'],
  69             previous_block=attrs['previous_block'],
  70             merkle_root=attrs['merkle_root'],
  71             timestamp=attrs['timestamp'],
  72             block_target=attrs['target'],
  73             share_target=bitcoin_data.HashType().unpack(getwork['target'].decode('hex')),
  74         )
  75
  76         if _check:
  77             extra = dict(getwork)
  78             del extra['data'], extra['hash1'], extra['target']
  79             extra.pop('midstate', None)
  80             getwork_check = ba.getwork(_check=False, **extra)
  81             if getwork_check != getwork and dict((k, v) for k, v in getwork_check.iteritems() if k != 'midstate') != getwork:
  82                 raise AssertionError('failed check - input invalid or implementation error')
  83
  84         return ba
  85
  86     def update(self, **kwargs):
  87         d = self.__dict__.copy()
  88         d.update(kwargs)
  89         return self.__class__(**d)
  90
  91 def decode_data(data):
  92     return bitcoin_data.block_header_type.unpack(_swap4(data.decode('hex'))[:80])