liuhongqiang
56 lines
1.6 KiB
Python
56 lines
1.6 KiB
Python
import re
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# skeleton from https://github.com/simon-engledew/python-chunks/blob/master/chunks/__init__.py
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def _from_pattern(pattern, type, *args):
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def coerce(value):
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value = str(value)
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match = pattern.search(value)
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if match is not None:
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return type(match.group(1), *args)
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raise ValueError('unable to coerce "%s" into a %s' %
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(value, type.__name__))
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return coerce
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to_megabytes = lambda n: n * 1024 * 1024
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to_hex = _from_pattern(re.compile('([-+]?[0-9A-F]+)', re.IGNORECASE), int, 16)
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def decode(fileobj, chunk_limit=to_megabytes(5)):
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""" Removes chunked encoding from fileobj """
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hexsizestr = ''
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len_size_bytes = 0
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while True:
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firstbyte = fileobj.read(1)
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if firstbyte == '\r':
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nextbyte = fileobj.read(1)
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assert nextbyte == '\n'
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else:
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len_size_bytes += 1
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hexsizestr += firstbyte
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if len_size_bytes > 100:
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raise OverflowError('too many digits...')
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continue
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length = to_hex(hexsizestr)
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hexsizestr = ''
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len_size_bytes = 0
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if length > chunk_limit:
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raise OverflowError(
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'invalid chunk size of "%d" requested, max is "%d"' % (length, chunk_limit))
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value = fileobj.read(length)
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assert len(value) == length
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yield value
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tail = fileobj.read(2)
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if not tail:
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raise ValueError('missing \\r\\n after chunk')
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assert tail == '\r\n', 'unexpected characters "%s" after chunk' % tail
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if not length:
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return
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