public inbox for git@vger.kernel.org 
 help / color / mirror / Atom feed
From: Junio C Hamano <gitster@pobox•com>
To: git@vger•kernel.org
Subject: Re: [PATCH v3 07/18] rerere: stop looping unnecessarily
Date: Fri, 24 Jul 2015 13:06:49 -0700	[thread overview]
Message-ID: <xmqq380dmiau.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <1437171880-21590-8-git-send-email-gitster@pobox.com> (Junio C. Hamano's message of "Fri, 17 Jul 2015 15:24:29 -0700")

Junio C Hamano <gitster@pobox•com> writes:

> handle_cache() loops 3 times starting from an index entry that is
> unmerged, while ignoring an entry for a path that is different from
> what we are looking for.
>
> As the index is sorted, once we see a different path, we know we saw
> all stages for the path we are interested in.  Just loop while we
> see the same path and then break, instead of continuing for 3 times.
>
> Signed-off-by: Junio C Hamano <gitster@pobox•com>
> ---
>  rerere.c | 17 +++++++----------
>  1 file changed, 7 insertions(+), 10 deletions(-)
>
> diff --git a/rerere.c b/rerere.c
> index 4c45f55..7b1419c 100644
> --- a/rerere.c
> +++ b/rerere.c
> @@ -329,24 +329,21 @@ static int handle_cache(const char *path, unsigned char *sha1, const char *outpu
>  		return -1;
>  	pos = -pos - 1;
>  
> -	for (i = 0; i < 3; i++) {
> +	while (pos < active_nr) {
>  		enum object_type type;
>  		unsigned long size;
> -		int j;
>  
> -		if (active_nr <= pos)
> -			break;
>  		ce = active_cache[pos++];
>  		if (ce_namelen(ce) != len || memcmp(ce->name, path, len))
> -			continue;
> -		j = ce_stage(ce) - 1;
> -		mmfile[j].ptr = read_sha1_file(ce->sha1, &type, &size);
> -		mmfile[j].size = size;
> +			break;
> +		i = ce_stage(ce) - 1;
> +		mmfile[i].ptr = read_sha1_file(ce->sha1, &type, &size);
> +		mmfile[i].size = size;

If the conflicted index has multiple stage #1 entries, this will leak
what was previously read.  As the array is initialized to NULLs, perhaps


	i = ce_stage(ce) - 1;
        if (!mmfile[i].ptr) {
		mmfile[i].ptr = read_sha1_file(ce->sha1, &type, &size);
                mmfile[i].size = size;
	}

should be sufficient.  This does change the semantics, in that we
used to use the last stage #1 entry as the common ancestor when
doing the plain-vanilla three-way merge, but with the leak fix, we
will use the first stage #1 entry.  But it does not change it in
any meaningful way---we are using only one of multiple stage #1
entries arbitrarily picked either way.

>  	}
> -	for (i = 0; i < 3; i++) {
> +	for (i = 0; i < 3; i++)
>  		if (!mmfile[i].ptr && !mmfile[i].size)
>  			mmfile[i].ptr = xstrdup("");
> -	}
> +
>  	/*
>  	 * NEEDSWORK: handle conflicts from merges with
>  	 * merge.renormalize set, too

  reply	other threads:[~2015-07-24 20:06 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-01  6:04 [PATCH v2 00/13] "rerere" minor clean-up Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 01/13] rerere: fix an off-by-one non-bug Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 02/13] rerere: plug conflict ID leaks Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 03/13] rerere: lift PATH_MAX limitation Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 04/13] rerere: write out each record of MERGE_RR in one go Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 05/13] rerere: report autoupdated paths only after actually updating them Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 06/13] rerere: drop want_sp parameter from is_cmarker() Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 07/13] rerere: stop looping unnecessarily Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 08/13] rerere: explain the rerere I/O abstraction Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 09/13] rerere: explain MERGE_RR management helpers Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 10/13] rerere: explain the primary codepath Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 11/13] rerere: explain "rerere forget" codepath Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 12/13] rerere: explain the remainder Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 13/13] rerere: refactor "replay" part of do_plain_rerere() Junio C Hamano
2015-07-17 22:24 ` [PATCH v3 00/18] "rerere" preparatory clean-up Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 01/18] rerere: fix an off-by-one non-bug Junio C Hamano
2015-07-24 19:46     ` Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 02/18] rerere: plug conflict ID leaks Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 03/18] rerere: lift PATH_MAX limitation Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 04/18] rerere: write out each record of MERGE_RR in one go Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 05/18] rerere: report autoupdated paths only after actually updating them Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 06/18] rerere: drop want_sp parameter from is_cmarker() Junio C Hamano
2015-07-18  8:24     ` Philip Oakley
2015-07-18  8:47       ` Eric Sunshine
2015-07-17 22:24   ` [PATCH v3 07/18] rerere: stop looping unnecessarily Junio C Hamano
2015-07-24 20:06     ` Junio C Hamano [this message]
2015-07-17 22:24   ` [PATCH v3 08/18] rerere: explain the rerere I/O abstraction Junio C Hamano
2015-07-24 20:42     ` Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 09/18] rerere: explain MERGE_RR management helpers Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 10/18] rerere: explain the primary codepath Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 11/18] rerere: explain "rerere forget" codepath Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 12/18] rerere: explain the remainder Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 13/18] rerere: refactor "replay" part of do_plain_rerere() Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 14/18] rerere: further de-dent do_plain_rerere() Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 15/18] rerere: further clarify do_rerere_one_path() Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 16/18] rerere: call conflict-ids IDs Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 17/18] rerere: use "struct rerere_id" instead of "char *" for conflict ID Junio C Hamano
2015-07-18  8:47     ` Eric Sunshine
2015-07-17 22:24   ` [PATCH v3 18/18] rerere: un-nest merge() further Junio C Hamano

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=xmqq380dmiau.fsf@gitster.dls.corp.google.com \
    --to=gitster@pobox$(echo .)com \
    --cc=git@vger$(echo .)kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox