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diff --git a/blog/2020/gsoc/article/4.md b/blog/2020/gsoc/article/4.md new file mode 100644 index 0000000..43738a7 --- /dev/null +++ b/blog/2020/gsoc/article/4.md @@ -0,0 +1,84 @@ ++++ +rss = "GSoC 2020: I've Walked 500 Miles..." +date = Date(2020, 7, 20) ++++ +@def tags = ["pip", "gsoc"] + +# I've Walked 500 Miles... + +> ... and I would walk 500 more\ +> Just to be the man who walks a thousand miles\ +> To fall down at your door +> +>  + +\toc + +## The Main Road + +Hi, have you met `fast-deps`? It's (going to be) the name of `pip`'s +experimental feature that may improve the speed of dependency resolution +of the new resolver. By avoid downloading whole wheels to just +obtain metadata, it is especially helpful when `pip` has to do +heavy backtracking to resolve conflicts. + +Thanks to {{pip 8532#discussion_r453990728 "Chris Hunt's review on GH-8537"}}, +my mentor Pradyun Gedam and I worked out a less hacky approach to inteject +the call to lazy wheel during the resolution process. A new PR {{pip 8588}} +was filed to implement it—I could have *just* worked on top of the old PR +and rebased, but my `git` skill is far from gud enuff to confidently do it. + +Testing this one has been a lot of fun though. At first, integration tests +were added as a rerun of the tests for the new resolver, with an additional flag +to use feature `fast-deps`. It indeed made me feel guilty towards [Travis][], +who has to work around 30 minutes more every run. Per Chris Hunt's suggestion, +in the new PR, I instead write a few functional tests for the area relating +the most to the feature, namely `pip`'s subcommands `wheel`, +`download` and `install`. + +It was also suggested that a mock server with HTTP range requests support +might be better (in term of performance and reliablilty) than for testing. +However, {{pip 8584#issuecomment-659227702 "I have yet to be able to make +Werkzeug do it"}}. + +Why did I say I'm half way there? With the parallel utilities merged and a way +to quickly get the list of distribution to be downloaded being really close, +what left is *only* to figure out a way to properly download them in parallel. +With no distribution to be added during the download progress, the model of this +will fit very well with the architecture in [my original proposal][]. +A batch downloader can be implemented to track the progress of each download +and thus report them cleanly as e.g. progress bar or percentage. This is +the part I am second-most excited about of my GSoC project this summer +(after the synchronization of downloads written in my proposal, which was then +superseded by `fast-deps`) and I can't wait to do it! + +## The Side Quests + +As usual, I make sure that I complete every side quest I see during the journey: + +* {{pip 8568}}: Declare constants in `configuration.py` as such +* {{pip 8571}}: Clean up `Configuration.unset_value` + and nit the class' `__init__` +* {{pip 8578}}: Allow verbose/quite level + to be specified via config file and env var +* {{pip 8599}}: Replace tabs by spaces for consistency + +## Snap Back to Reality + +A bit about me, I actually walked 500 meters earlier today to a bank +and walked 500 more to another to prepare my Visa card for purchasing +the upcoming Pinephone prototype. It's one of the first smartphones +to fully support a GNU/Linux distribution, where one can run desktop apps +(including proper terminals) as well as traditional services like SSH, +HTTP server and IPFS node because why not? Just a few hours ago, +I pre-ordered the [postmarketOS community edition][] with additional hardware +for convergence. + +If you did not come here for a Pinephone ad, please take my apologies though d-; +and to ones reading this, I hope you all can become the person who walks +a thousand miles to fall down at the door opening to all +what you ever wished for! + +[Travis]: https://travis-ci.com +[my original proposal]: /assets/pip-parallel-dl.pdf +[postmarketOS community edition]: https://postmarketos.org/blog/2020/07/15/pinephone-ce-preorder/ |