Re: [PATCH] diff: don't read index when --no-index is given
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Dec 9, 2013, 20:30 UTC
- Message-ID
- <xmqqwqjdydga.fsf@gitster.dls.corp.google.com>
- In-Reply-To
- <1386590745-4412-1-git-send-email-t.gummerer@gmail.com>
Thomas Gummerer <t.gummerer@gmail.com> writes:
Show 39 quoted lines
> git diff --no-index ... currently reads the index, during setup, when
> calling gitmodules_config(). In the usual case this gives us some
> performance drawbacks, but it's especially annoying if there is a broken
> index file.
>
> Avoid calling the unnecessary gitmodules_config() when the --no-index
> option is given. Also add a test to guard against similar breakages in the future.
>
> Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
> ---
> builtin/diff.c | 13 +++++++++++--
> t/t4053-diff-no-index.sh | 6 ++++++
> 2 files changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/builtin/diff.c b/builtin/diff.c
> index adb93a9..47c0833 100644
> --- a/builtin/diff.c
> +++ b/builtin/diff.c
> @@ -257,7 +257,7 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
> int blobs = 0, paths = 0;
> const char *path = NULL;
> struct blobinfo blob[2];
> - int nongit;
> + int nongit, no_index = 0;
> int result = 0;
>
> /*
> @@ -282,9 +282,18 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
> *
> * Other cases are errors.
> */
> + for (i = 1; i < argc; i++) {
> + if (!strcmp(argv[i], "--"))
> + break;
> + if (!strcmp(argv[i], "--no-index")) {
> + no_index = 1;
> + break;
> + }
> + }This seems to duplicate only half the logic at the beginning of diff_no_index(), right? E.g., running "git diff /var/tmp/[12]" inside a working tree that is controlled by a Git repository when /var/tmp/ is outside, we do want to behave as if the command line were "git diff --no-index /var/tmp/[12]", but this half duplication makes these two behave differently, no?
I think the issue you are trying to address is worth tackling, but I wonder if a bit of preparatory refactoring is necessary to avoid the partial duplication.
Show 22 quoted lines
> prefix = setup_git_directory_gently(&nongit); > - gitmodules_config(); > + if (!no_index) > + gitmodules_config(); > git_config(git_diff_ui_config, NULL); > > init_revisions(&rev, prefix); > diff --git a/t/t4053-diff-no-index.sh b/t/t4053-diff-no-index.sh > index 979e983..a24ae4d 100755 > --- a/t/t4053-diff-no-index.sh > +++ b/t/t4053-diff-no-index.sh > @@ -29,4 +29,10 @@ test_expect_success 'git diff --no-index relative path outside repo' ' > ) > ' > > +test_expect_success 'git diff --no-index with broken index' ' > + cd repo && > + echo broken >.git/index && > + test_expect_code 0 git diff --no-index a ../non/git/a > +' > + > test_done