31 lines
726 B
Python
31 lines
726 B
Python
# external imports
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import sha3
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class LogBloom:
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"""Helper for Ethereum receipt log bloom filters.
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"""
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def __init__(self):
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self.content = bytearray(256)
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def add(self, element):
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"""Add topic element to filter.
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:param element: Topic element
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:type element: bytes
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"""
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if not isinstance(element, bytes):
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raise ValueError('element must be bytes')
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h = sha3.keccak_256()
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h.update(element)
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z = h.digest()
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for j in range(3):
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c = j * 2
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v = int.from_bytes(z[c:c+2], byteorder='big')
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v &= 0x07ff
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m = 255 - int(v / 8)
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n = v % 8
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self.content[m] |= (1 << n)
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