Re: [PATCH 1/3] revision: complicated pathspecs disable filters
- From
Derrick Stolee <stolee@gmail.com>
- Date
- Apr 13, 2020, 11:54 UTC
- Message-ID
- <4a3af6a9-50ef-1759-7e4c-56f6c5af542a@gmail.com>
- In-Reply-To
- <20200413000748.GA55122@syl.local>
On 4/12/2020 8:07 PM, Taylor Blau wrote:
Show 22 quoted lines
> On Sun, Apr 12, 2020 at 03:30:07PM -0700, Junio C Hamano wrote: >> Taylor Blau <me@ttaylorr.com> writes: >> >>> I certainly wouldn't complain about a comment here explaining these >>> three checks, but I suppose that the rationale is only a 'git blame' >>> away (and I guess that is faster now after this series ;-)). >>> >>>> + if (revs->prune_data.has_wildcard) >>>> + return; >>>> + if (revs->prune_data.nr > 1) >>>> + return; >>>> + if (revs->prune_data.magic || >>>> + (revs->prune_data.nr && >>>> + revs->prune_data.items[0].magic)) >> >> This says "any magic", but it is overly pessimistic to disable the >> optimization for "literal" magic. That magic is the one that lets >> well written scripts to say "I have in a '$variable' that the user >> gave me as a pathname (not pathspec), and it may have a wildcard >> letter in it, but please treat it as a literal string" by prefixing >> ":(literal)" before that user-supplied data, so it is punishing well >> disciplined folks.
This is a good point. I'm unfamiliar with these advanced pathspec tricks.
Show 27 quoted lines
> I hadn't thought of that, but it makes sense to me. How about something
> like this squashed into this patch? I moved the if-chain that Stolee
> introduced out to its own function, at least since they seem
> well-contained and related to one another. I figure that this simplifies
> the implementation of 'prepare_to_use_bloom_filter' by giving the reader
> less to think about up-front.
>
> diff --git a/revision.c b/revision.c
> index 534c0bf996..15bf4ccff5 100644
> --- a/revision.c
> +++ b/revision.c
> @@ -654,6 +654,18 @@ static void trace2_bloom_filter_statistics_atexit(void)
> jw_release(&jw);
> }
>
> +static int has_bloom_key(struct pathspec *spec)
> +{
> + if (spec->has_wildcard)
> + return 0;
> + if (spec->nr > 1)
> + return 0;
> + if ((spec->magic & ~PATHSPEC_LITERAL) ||
> + (spec->nr && spec->items[0].magic & ~PATHSPEC_LITERAL))
> + return 0;
> + return 1;
> +}
> +Perhaps flip this on its head?
+static int forbids_bloom_key(struct pathspec *spec)
+{
+ if (spec->has_wildcard)
+ return 1;
+ if (spec->nr > 1)
+ return 1;
+ if (spec->magic & ~PATHSPEC_LITERAL)
+ return 1;
+ if (spec->nr && (spec->items[0].magic & ~PATHSPEC_LITERAL))
+ return 1;
+ return 0;
+}
+Show 16 quoted lines
> static void prepare_to_use_bloom_filter(struct rev_info *revs)
> {
> struct pathspec_item *pi;
> @@ -665,13 +677,7 @@ static void prepare_to_use_bloom_filter(struct rev_info *revs)
> if (!revs->commits)
> return;
>
> - if (revs->prune_data.has_wildcard)
> - return;
> - if (revs->prune_data.nr > 1)
> - return;
> - if (revs->prune_data.magic ||
> - (revs->prune_data.nr &&
> - revs->prune_data.items[0].magic))
> + if (!has_bloom_key(&revs->prune_data))
> return;Then this would be "if (forbids_bloom_key(&revs->prune_data))"
Generally, I like pulling this stuff out as a method to isolate and label its purpose. If we wanted to allow certain :(icase) things later, then we know what to modify in order to "allow" it.
Thanks, -Stolee