60 lines
1.5 KiB
Python
60 lines
1.5 KiB
Python
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from gzip import GzipFile
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# 256K buffer to Gzip
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GZIP_BUFFER_SIZE = 1024 * 256
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class GzipWrap(object):
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def __init__(self, input, filename=None, compresslevel=1):
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self.input = iter(input)
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self.buffer = ''
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self.zipper = GzipFile(filename, mode='wb', fileobj=self, compresslevel=compresslevel, mtime=0)
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self.is_done = False
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def read(self, size=-1):
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if size is None or size < 0:
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raise Exception('Call to GzipWrap with unbound size will result in poor performance')
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# If the buffer already has enough bytes, then simply pop them off of
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# the beginning and return them.
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if len(self.buffer) >= size or self.is_done:
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ret = self.buffer[0:size]
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self.buffer = self.buffer[size:]
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return ret
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# Otherwise, zip the input until we have enough bytes.
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while True:
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# Attempt to retrieve the next bytes to write.
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is_done = False
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input_size = 0
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input_buffer = ''
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while input_size < GZIP_BUFFER_SIZE:
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try:
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s = self.input.next()
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input_buffer += s
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input_size = input_size + len(s)
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except StopIteration:
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is_done = True
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break
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self.zipper.write(input_buffer)
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if is_done:
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self.zipper.flush()
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self.zipper.close()
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self.is_done = True
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if len(self.buffer) >= size or is_done:
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ret = self.buffer[0:size]
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self.buffer = self.buffer[size:]
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return ret
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def flush(self):
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pass
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def write(self, data):
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self.buffer += data
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def close(self):
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self.input.close()
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