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Switch to new-style callbacks

See original GitHub issue

See: https://cffi.readthedocs.io/en/latest/using.html#extern-python-new-style-callbacks

The original callbacks are slower to invoke and have the same issue as libffi’s callbacks; notably, see the warning. The new style described in the present section does not use libffi’s callbacks at all.

Occurrences of ffi.callback: https://github.com/libvips/pyvips/blob/1dc365a3beb6484d609d3aa725cd871c68af2ef0/pyvips/gvalue.py#L23 (Seems no longer used ?)

https://github.com/libvips/pyvips/blob/52e218462af9261766f5aebf60b8a39ef0c3e2c2/pyvips/__init__.py#L134 (Used by the log handler)

https://github.com/libvips/pyvips/blob/52e218462af9261766f5aebf60b8a39ef0c3e2c2/pyvips/base.py#L87 (Used by the documentation generator)

https://github.com/libvips/pyvips/blob/1dc365a3beb6484d609d3aa725cd871c68af2ef0/pyvips/voperation.py#L106 (Hot path code, used by almost all pyvips operations. Perhaps we should use vips_object_get_args for libvips 8.7+. See the lua-vips implementation)

This comment can also be solved using the new style callbacks.

After this has been resolved, we should look at https://github.com/libvips/pyvips/issues/21 again and benchmark it under cffi’s API mode (the Pillow performance test suite still depends on an older version of pyvips which doesn’t support the API mode).

Issue Analytics

State:
Created 5 years ago
Comments:21 (17 by maintainers)

Top GitHub Comments

1reaction

ollie-bellcommented, Dec 23, 2021

If I do a conda install libvips cffi pkgconfig followed by pip install pyvips then it does correctly build pyvips in API mode, and is using the conda libvips binaries. Just for whatever reason, a conda install pyvips will build in ABI mode. I’ll open an issue on the conda-forge pyvips feedstock page for that.

0reactions

jcupittcommented, Dec 23, 2021

I think mixing conda and homebrew binaries in one process is not really supported and it likely to bite you at some point. My understanding (maybe wrong) is that you are supposed to use the conda libvips binaries with conda python.

(I use homebrew for everything on macos, fwiw)

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