From: Jeff Hostetler <git@jeffhostetler.com>
Date: Fri, 19 May 2017 12:25:05 GMT
Subject: Re: [WIP/RFC 00/23] repository object
Message-ID: <623e5473-9fb0-07e4-0ac1-adabdc652c74@jeffhostetler.com>
In-Reply-To: <20170518232134.163059-1-bmwill@google.com>



On 5/18/2017 7:21 PM, Brandon Williams wrote:
> When I first started working on the git project I found it very difficult to
> understand parts of the code base because of the inherently global nature of
> our code.  It also made working on submodules very difficult.  Since we can
> only open up a single repository per process, you need to launch a child
> process in order to process a submodule.  But you also need to be able to
> communicate other stateful information to the children processes so that the
> submodules know how best to format their output or match against a
> pathspec...it ends up feeling like layering on hack after hack.  What I would
> really like to do, is to have the ability to have a repository object so that I
> can open a submodule in-process.
> 
> Before this becomes a reality for all commands, much of the library code would
> need to be refactored in order to work purely on handles instead of global
> state.  As it turned out, ls-files is a pretty simple command and doesn't have
> *too* many dependencies.  The biggest thing that needed to be changed was
> piping through an index into a couple library routines so that they don't
> inherently rely on 'the_index'.  A few of these changes I've sent out and can
> be found at 'origin/bw/pathspec-sans-the-index' and
> 'origin/bw/dir-c-stops-relying-on-the-index' which this series is based on.
> 
> Patches 1-16 are refactorings to prepare either library code or ls-files itself
> to be ready to handle passing around an index struct.  Patches 17-22 introduce
> a repository struct and change a couple of things about how submodule caches
> work (getting submodule information from .gitmodules).  And Patch 23 converts
> ls-files to use a repository struct.
> 
> The most interesting part of the series is from 17-23.  And 1-16 could be taken
> as is without the rest of the series.
> 
> This is still very much in a WIP state, though it does pass all tests.  What
> I'm hoping for here is to get a discussion started about the feasibility of a
> change like this and hopefully to get the ball rolling.  Is this a direction we
> want to move in?  Is it worth the pain?
> 
> Thanks for taking the time to look at this and entertain my insane ideas :)

Very nice and thanks for starting this.
Jeff