[PATCH] match: adding non-recursive directory matching

Thu Jan 26 20:27:17 EST 2017

All sounds very reasonable, and "filesin:" or "rootfilesin:" LGTM.

On Thu, Jan 26, 2017 at 11:24 AM, Martin von Zweigbergk <
martinvonz at google.com> wrote:

> On Thu, Jan 26, 2017 at 11:19 AM, FUJIWARA Katsunori
> <foozy at lares.dti.ne.jp> wrote:
> >
> > At Wed, 25 Jan 2017 20:54:37 -0800,
> > Martin von Zweigbergk wrote:
> >>
> >> On Mon, Jan 23, 2017 at 5:02 PM, Rodrigo Damazio via Mercurial-devel
> >> <mercurial-devel at mercurial-scm.org> wrote:
> >> > Getting back to this after the end-of-year hiatus (yes, I know it
> happens to
> >> > be during another code freeze :) I seem to have good timing).
> >> >
> >> > On Tue, Dec 27, 2016 at 2:14 AM, Pierre-Yves David
> >> > <pierre-yves.david at ens-lyon.org> wrote:
> >> >>
> >> >>
> >> >>
> >> >> On 12/21/2016 04:21 AM, Rodrigo Damazio wrote:
> >> >>>
> >> >>>     If I got these two pieces right, it looks like we could just
> apply
> >> >>>     the improvement to 'visitdir' to 'set:your/glob/*' and have your
> >> >>>     usecase filled while not jumping into UI changes. Would that
> work
> >> >>>     for you ?
> >> >>>
> >> >>>
> >> >>> Not without a third set of changes, since set expansion doesn't use
> >> >>> visitdir (or the matcher being built) at all - the dependency is
> that
> >> >>> building the matcher depends on expanding the set (and thus the set
> >> >>> can't depend on the matcher).
> >> >>> It would technically be doable for re:, but I'm wary of getting
> into the
> >> >>> business of parsing and special-casing regexes to assume what they
> match
> >> >>> or don't.
> >> >>
> >> >>
> >> >> Rodrigo and I chatted directly about this a couple of days ago. Here
> is a
> >> >> quick summary of my new understanding of the situation.
> >> >>
> >> >> Fileset
> >> >> -------
> >> >>
> >> >> Fileset (behind "set:") can give the right result, but it is powered
> by
> >> >> not very modern code, it follow the old revset principle of "get
> everything
> >> >> and then run filters on that everything". That does not fit Rodrigo
> needs at
> >> >> all. It was easy to make 'set:' a bit smarter in the simple case but
> then we
> >> >> get into the issue that the matcher class is using 'set:' in a
> strange,
> >> >> non-lazy, way that does not use all the 'visitdir' feature
> Rodrigo/Google
> >> >> needs.
> >> >>
> >> >> So in short, fileset needs a rework before being usable in a
> demanding
> >> >> context.
> >> >>
> >> >>
> >> >> Current path restriction capability
> >> >> -----------------------------------
> >> >>
> >> >> The 'Match' class already have logic to restrict the path visited
> >> >> (implemented in the 'visitdir' method). To clarify, this logic as no
> effect
> >> >> on the returned match but is only an optimization for the directory
> we
> >> >> visit. It seems to only kicks in when treemanifest is used.
> >> >> This logic already works with a couple of patterns type (all pattern
> use
> >> >> the same class). However, that logic currently do not support the
> case were
> >> >> one want to select some subdirectory and skips the rest of the
> subtrees
> >> >> under it.
> >> >
> >> >
> >> > That is correct.
> >> >
> >> >> note: Rodrigo, you seems to have a good understanding of the logic.
> Do you
> >> >> think you could document the involved attributes (_includeroots,
> >> >> _includedirs, _excluderoots, etc) That would help a lot the next
> poor souls
> >> >> looking at the code.
> >> >
> >> >
> >> > Sure. It took me a while to understand that "roots" means "recursive
> >> > directories" and "dirs" means "non-recursive directories" in that
> code - it
> >> > all became much more clear after that. I'll be sure to add comments
> in my
> >> > patch and/or rename the attributes.
> >> >
> >> >>
> >> >>
> >> >> Way forward
> >> >> -----------
> >> >>
> >> >> That limitation in the matcher class optimization is the main
> blocker for
> >> >> Rodrigo/Google needs. The optimization is independent of the UI part
> we
> >> >> actually provides to user as all patterns use the same matcher class
> and
> >> >> some existing class could already benefit from this optimization.
> >> >>
> >> >> Rodrigo seems to have a patch to update the matcher code to track and
> >> >> optimize the "subdir-but-not-subtree" case. He has not submitted
> this patch
> >> >> yet. Submitting that patches seems the next step to me. It will get
> the
> >> >> matcher code in a state that can actually be used for the
> >> >> narrowhg+treemanifest usecase.
> >> >>
> >> >> Once that code is in, it seems easy to make sure various patterns
> use it
> >> >> basic, easily recognizable cases. We poked at updating the code to
> have
> >> >> basic regexp matching a subtree recognized as such and that was
> quite easy.
> >> >>
> >> >>
> >> >> Rodrigo, does that match your current understanding of the situation?
> >> >
> >> >
> >> > It does.
> >> > And just to clarify on the patches - I sent an initial patch, then
> after
> >> > comments changes it significantly, so those are two different changes:
> >> >
> >> > The first implements a "files:" matcher which matches all files
> inside a
> >> > directory, non-recursively. This has no wildcards, so special-casing
> it in
> >> > visitdir and any other places needed results in clean and simple code
> ("if
> >> > it's files:, don't recurse").
> >> > The second implements "rootglob:" which allows any number of
> wildcards at
> >> > point in the path, and is part of Foozy's plan for the new set of
> matchers.
> >> > This adds some complexity in splitting dirs and roots (mentioned
> above) by
> >> > having to parse the wildcards, and then the visitdir change looks
> less clean
> >> > ("if it's a rootglob that has a single /* wildcard at the end, then
> don't
> >> > recurse" - other cases are possible but start to get more complex).
> >> >
> >> > For these reasons, I'd still prefer to get "files:" or similar in,
> but I'm
> >> > open for doing it either way. Please advise on the preferred way and
> I'll
> >> > send an updated patch (2 patches really - one for the matcher, one
> for the
> >> > visitdir optimization which makes it work with narrow).
> >>
> >> I'm fine with not doing rootglob:, but if I read foozy's proposal
> >> right, the proposed files: will be what he would call rootfiles:. I
> >> liked his proposal for a systematic naming, and if I got that right, I
> >> think we should call it that from the beginning so we don't end up
> >> with more aliases.
> >
> > Yeah, we should avoid confusion of naming !
> >
> >> I'd also like "rootfiles:foo" to *not* match the
> >> file "foo", but only files in the directory "foo/". I mention that
> >> because last I heard, he was unsure about that himself. Foozy, do you
> >> agree?
> >
> > I don't have strong opinion against mode "XXX:", which matches against
> > both "just this file" and "files directly under this directory"
> >
> > Therefore, I agree with adding new mode "XXX:", if it is needed (and
> > Rodrigo/Google think so).
> >
> > But, name "files:" doesn't seem to suit for "XXX:" mode (at least, for
> > me).
> >
> > Even if it matches against only "files directly under this directory",
> > "files:" doesn't yet.
> >
> > Maybe, root cause of my bad feel is that "foo" of "files:foo" should
> > be the directory in both cases, even though mode name "files:" has
> > less "(under) this directory" flavor.
> >
> > If it is possible to combine 2 modes below for solving issues of
> > Rodrigo/Google, I'm +1 for splitting "XXX:" into them, because naming
> > "YYY:" should be easier than naming "XXX:".
> >
> >   - "file:" matching against "just this file"
> >   - "YYY:" matching against "files directly under this directory"
> >
> > Are there any better (and short enough) names for "XXX:" or "YYY:"
> > than "files:" ?
> >
> >   - "filesin:" (Files-In) for "YYY:" (<=> "files under" as "dir:") ?
> >   - "fileorin:" (File-Or-(Files-)In) for "XXX:" ?
> >
> > Of course, I'm also OK with naming "XXX:" or "YYY:" as "files:", to go
> > forward :-)
>
> I like "file:" and "filesin:" for those two cases. But we should add
> the "root" prefix so we don't have to do that later, right?
>
> >
> >>
> >> >
> >> > Thanks
> >> > Rodrigo
> >> >
> >> >
> >> > _______________________________________________
> >> > Mercurial-devel mailing list
> >> > Mercurial-devel at mercurial-scm.org
> >> > https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel
> >> >
> >>
> >
> > --
> > ----------------------------------------------------------------------
> > [FUJIWARA Katsunori]                             foozy at lares.dti.ne.jp
>
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