Re: [PATCH v1 3/5] list-objects-filter: implement composite filters

From: Jeff Hostetler <git@jeffhostetler.com>
Date: May 30, 2019, 14:01 UTC
Message-ID: <0d8973e7-5b29-fb09-a435-3bf2ec23269f@jeffhostetler.com>
In-Reply-To: <20190529232746.GE4700@comcast.net>

On 5/29/2019 7:27 PM, Matthew DeVore wrote:

Show 28 quoted lines

> On Wed, May 29, 2019 at 05:29:14PM -0400, Jeff Hostetler wrote:
>> Was sparse:path filter the only reason for needing all the URL encoding?
>> The sparse:oid form allows values <ref>:<path> and these (or at least
>> the <path> portion) may contain special characters.  So don't we need to
>> URL encode this form too?
> 
> Oh, I missed this. I was only thinking an oid was allowed after "sparse:". So as
> I suspected I was overlooking something obvious.
> 
> Now I just want to understand the objection to URL encoding a little better. I
> haven't worked with in a project that requires a lot of boilerplate before, so I
> may be asking obvious things again. If so, sorry in advance.
> 
> So the objections, as I interpret them so far, are that:
> 
>   a the URL encoding/decoding complicates the code base
>   b explaining the URL encoding, while it allows for future expansion, requires
>     some verbose documentation in git-rev-list that is potentially distracting or
>     confusing
>   c there may be a better way to allow for future expansion that does not require
>     URL encoding
>   d the URL encoding is unpleasant to use (note that my patchset makes it
>     optional for the user to use and it is only mandatory in sending it over the
>     wire)
> 
> I think these are reasonable and I'm willing to stop digging my heels in :) Does
> the above sum everything up?
>

My primary concern was how awkward it would be to use the URL encoding syntax on the command line, but as you say, that can be avoided by using the multiple --filter args.

And to be honest, the wire format is hidden from user view, so it doesn't really matter there. So either approach is fine. I was hoping that the "filters (plural)" approach would let us avoid URL encoding, but that comes with its own baggage as you suggested. And besides, URL encoding is well-understood.

And I don't want to prematurely complicate this with ANDs ORs and XORs as you mention in another thread.

So don't let me stop this effort.

BTW, I don't think I've seen this mentioned anywhere and I don't remember if this got into the code or not. But we discussed having a repo-local config setting to remember the filter-spec used by the partial clone that would be inherited by a subsequent (partial) fetch. Or would be set by the first partial fetch following a normal clone. Having a single composite filter spec would help with this.

Jeff