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On 02/23/2018 06:58 PM, Daniel Robbins wrote: |
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> Hi there, |
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> |
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> Zac Medico and I would like to discuss the following at the next council |
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> meeting: moving Portage to support only python3.6+. One of the primary |
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> benefits of this change is that it will allow us to use python's native |
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> async implementation as we look to make Portage faster at a critical |
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> time when we are looking to improve Portage performance. As we approach |
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> the stabilization of python3.6 in Gentoo, it seems like a good time to |
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> discuss the process of jettisoning 2.7 support and standardizing on 3.6 |
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> for Portage. |
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> |
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> Right now, a custom 'asyncio-like' set of classes is used for async in |
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> Portage. This limits interoperability with other async-friendly python |
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> modules and produces additional maintenance overhead for the project. |
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> |
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> Maybe even more importantly, 3.6+ compatibility also gives us the |
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> ability to use many other new language features and reduce the |
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> maintenance overhead of having 2.7 compatibility for the extensive |
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> Portage code-base. We expect that this will improve the velocity of |
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> Portage development, provide opportunities to improve Portage |
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> functionality and also allow us clean up a lot of unnecessarily complex |
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> code (and eliminate code) that is there only to ensure compatibility |
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> with 2.7. |
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> |
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> Best, |
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> |
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> Daniel |
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|
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In portage-2.3.30, portage's python API includes an asyncio event loop |
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policy that is compatible with PEP 492 coroutines using async and await |
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syntax [1]. This is possible while still maintaining backward |
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compatibility with python2.7, though obviously you need to use a newer |
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python if you want to use async and await syntax. |
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|
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I've posted a code example that is compatible with python2.7 and uses |
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portage's event loop policy to do the same thing as emerge --regen, |
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complete with --jobs and --load-average options [2]. |
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|
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[1] https://www.python.org/dev/peps/pep-0492/ |
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[2] |
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https://blogs.gentoo.org/zmedico/2018/04/17/portage-api-asyncio-event-loop/ |
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-- |
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Thanks, |
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Zac |
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