Add Cython utils needed for zero-copy import and export.

[eriknw]

I'd like to add a few tests for this code, but it may be sufficient if grblas tests pass.

[eriknw]

This allows grblas to be a pure Python package: python-graphblas/python-graphblas#84

I still want to move some initialization logic for calling GxB_init to suitesparse_graphblas so that pygraphblas and grblas don't both try to initialize GraphBLAS.

[michelp]

This can also be done defensively, call GxB_Global_Option_get() and if it GrB_PANICs then the library is not initialized.

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On Thu, Apr 22, 2021 at 5:07 PM Erik Welch ***@***.***> wrote: This allows grblas to be a pure Python package: python-graphblas/python-graphblas#84 <python-graphblas/python-graphblas#84> I still want to move some initialization logic for calling GxB_init to suitesparse_graphblas so that pygraphblas and grblas don't both try to initialize GraphBLAS. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#9 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAA6BCKQ6J2VSAEORE6CXFLTKC23VANCNFSM43NDJYBQ> .

[eriknw]

Whoops, I just saw your comment @michelp! Yeah, each library could check using such a mechanism. I defined initialize and is_initialized functions in ssgb (my current abbreviation for this package) instead. Thanks for the trick!

initialize allows one to choose between using numpy's memory allocators or not. I'm curious to do benchmarking to see if it makes a difference.

I think this is ready for final review and merging.