7aa57f5cee
Add parameters to exercise placeholder for variable-length-quantity. Also changed variable naming from bytes to bytes_ to avoid shadowing python's bytes Fixes: #651
35 lines
639 B
Python
35 lines
639 B
Python
EIGHTBITMASK = 0x80
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SEVENBITSMASK = 0x7f
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def encode_single(n):
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bytes_ = [n & SEVENBITSMASK]
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n >>= 7
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while n > 0:
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bytes_.append(n & SEVENBITSMASK | EIGHTBITMASK)
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n >>= 7
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return bytes_[::-1]
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def encode(numbers):
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return sum((encode_single(n) for n in numbers), [])
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def decode(bytes_):
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values = []
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n = 0
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for i, byte in enumerate(bytes_):
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n <<= 7
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n += (byte & SEVENBITSMASK)
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if byte & EIGHTBITMASK == 0:
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values.append(n)
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n = 0
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elif i == len(bytes_) - 1:
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raise ValueError('incomplete byte sequence')
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return values
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