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  • Committer: John Arbash Meinel
  • Date: 2009-06-12 18:05:15 UTC
  • mto: (4371.4.5 vila-better-heads)
  • mto: This revision was merged to the branch mainline in revision 4449.
  • Revision ID: john@arbash-meinel.com-20090612180515-t0cwbjsnve094oik
Add a failing test for handling nodes that are in the same linear chain.

It fails because the ancestry skipping causes us to miss the fact that the two nodes
are actually directly related. We could check at the beginning, as the 
code used to do, but I think that will be incomplete for the more-than-two
heads cases.

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bzrlib/tuned_gzip.py
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    width=-zlib.MAX_WBITS, mem=zlib.DEF_MEM_LEVEL,
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    crc32=zlib.crc32):
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    """Create a gzip file containing bytes and return its content."""
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    return chunks_to_gzip([bytes])
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def chunks_to_gzip(chunks, factory=zlib.compressobj,
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    level=zlib.Z_DEFAULT_COMPRESSION, method=zlib.DEFLATED,
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    width=-zlib.MAX_WBITS, mem=zlib.DEF_MEM_LEVEL,
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    crc32=zlib.crc32):
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    """Create a gzip file containing chunks and return its content.
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    :param chunks: An iterable of strings. Each string can have arbitrary
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        layout.
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    """
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    result = [
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        '\037\213'  # self.fileobj.write('\037\213')  # magic header
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        '\010'      # self.fileobj.write('\010')      # compression method
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    # using a compressobj avoids a small header and trailer that the compress()
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    # utility function adds.
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    compress = factory(level, method, width, mem, 0)
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    crc = 0
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    total_len = 0
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    for chunk in chunks:
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        crc = crc32(chunk, crc)
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        total_len += len(chunk)
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        zbytes = compress.compress(chunk)
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        if zbytes:
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            result.append(zbytes)
 
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    result.append(compress.compress(bytes))
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    result.append(compress.flush())
 
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    result.append(struct.pack("<L", LOWU32(crc32(bytes))))
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    # size may exceed 2GB, or even 4GB
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    result.append(struct.pack("<LL", LOWU32(crc), LOWU32(total_len)))
 
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    result.append(struct.pack("<L", LOWU32(len(bytes))))
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    return ''.join(result)
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