[issue41486] Add _BlocksOutputBuffer for bz2/lzma/zlib module

[Ma Lin]

Ma Lin <malincns at 163.com> added the comment:

I modify lzma module to use different growth factors, see attached picture different_factors.png

1.5x should be the growth factor of _PyBytesWriter under Windows.

So if change _PyBytesWriter to use memory blocks, maybe there will be no performance improvement.

Over allocate factor of _PyBytesWriter:

    # ifdef MS_WINDOWS
        # define OVERALLOCATE_FACTOR 2
    # else
        # define OVERALLOCATE_FACTOR 4
    # endif

(I'm using Windows 10)

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Added file: https://bugs.python.org/file49544/different_factors.png

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