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26 lines
537 B
Python
26 lines
537 B
Python
# this is the rolling hash Epic uses, it appears to be a variation on CRC-64-ECMA
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hash_poly = 0xC96C5795D7870F42
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hash_table = []
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def _init():
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for i in range(256):
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for _ in range(8):
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if i & 1:
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i >>= 1
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i ^= hash_poly
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else:
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i >>= 1
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hash_table.append(i)
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def get_hash(data):
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if not hash_table:
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_init()
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h = 0
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for i in range(len(data)):
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h = ((h << 1 | h >> 63) ^ hash_table[data[i]]) & 0xffffffffffffffff
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return h
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