[pypy-issue] [issue1695] complexity of bytearray operations

[Johannes Baiter]

Johannes Baiter <johannes.baiter at gmail.com> added the comment:

I got bitten by this when running my jpegtran bindings under PyPy.
To extract EXIF data from JPEG images, I'm using indexed access on bytearrays a lot.
To illustrate the issue, the following (using IPython):

[1] import jpegtran
[2] %timeit -n10 -r5 jpegtran.JPEGImage('someimage.jpg').exif_thumbnail.as_blob()

gives 49.1ms as a 'best case' on CPython while it's ~2570ms on PyPy.
The source for the module can be found here:
https://github.com/jbaiter/jpegtran-cffi/blob/master/jpegtran/lib.py#L150

I also attached profiling data for PyPy.

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nosy: +jbaiter
status: unread -> chatting

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