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# MIT License |
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# |
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# Copyright (c) 2017 Matt Boyer |
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# |
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# Permission is hereby granted, free of charge, to any person obtaining a copy |
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# of this software and associated documentation files (the "Software"), to deal |
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# in the Software without restriction, including without limitation the rights |
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# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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# copies of the Software, and to permit persons to whom the Software is |
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# furnished to do so, subject to the following conditions: |
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# |
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# The above copyright notice and this permission notice shall be included in |
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# all copies or substantial portions of the Software. |
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# |
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
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# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
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# SOFTWARE. |
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View Code Duplication |
class Varint(object): |
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def __init__(self, varint_bytes): |
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self._bytes = varint_bytes |
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self._len = 0 |
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self._value = 0 |
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varint_bits = [] |
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for b in self._bytes: |
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self._len += 1 |
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if b & 0x80: |
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varint_bits.append(b & 0x7F) |
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else: |
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varint_bits.append(b) |
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break |
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varint_twos_complement = 0 |
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for position, b in enumerate(varint_bits[::-1]): |
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varint_twos_complement += b * (1 << (7*position)) |
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self._value = decode_twos_complement( |
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int.to_bytes(varint_twos_complement, 4, byteorder='big'), 64 |
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) |
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def __int__(self): |
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return self._value |
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def __len__(self): |
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return self._len |
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def __repr__(self): |
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return "<Varint {} ({} bytes)>".format(int(self), len(self)) |
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class IndexDict(dict): |
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def __iter__(self): |
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for k in sorted(self.keys()): |
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yield k |
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def decode_twos_complement(encoded, bit_length): |
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assert(0 == bit_length % 8) |
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encoded_int = int.from_bytes(encoded, byteorder='big') |
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mask = 2**(bit_length - 1) |
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value = -(encoded_int & mask) + (encoded_int & ~mask) |
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return value |
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mattboyer /
sqbrite
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