From: Junio C Hamano <gitster@pobox•com>
To: "Nguyễn Thái Ngọc Duy" <pclouds@gmail•com>
Cc: git@vger•kernel.org, worley@alum•mit.edu
Subject: Re: [PATCH v3 6/6] diff: shortcut for diff'ing two binary SHA-1 objects
Date: Thu, 14 Aug 2014 10:17:45 -0700 [thread overview]
Message-ID: <xmqqy4ur0z46.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <1407927454-9268-7-git-send-email-pclouds@gmail.com> ("Nguyễn Thái Ngọc Duy"'s message of "Wed, 13 Aug 2014 17:57:34 +0700")
Nguyễn Thái Ngọc Duy <pclouds@gmail•com> writes:
> If we are given two SHA-1 and asked to determine if they are different
> (but not _what_ differences), we know right away by comparing SHA-1.
>
> A side effect of this patch is, because large files are marked binary,
> diff-tree will not need to unpack them. 'diff-index --cached' will not
> either. But 'diff-files' still does.
>
> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail•com>
> ---
> diff.c | 13 +++++++++++++
> t/t1050-large.sh | 8 ++++++++
> 2 files changed, 21 insertions(+)
>
> diff --git a/diff.c b/diff.c
> index d381a6f..b85bcfb 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -2324,6 +2324,19 @@ static void builtin_diff(const char *name_a,
> } else if (!DIFF_OPT_TST(o, TEXT) &&
> ( (!textconv_one && diff_filespec_is_binary(one)) ||
> (!textconv_two && diff_filespec_is_binary(two)) )) {
> + if (!one->data && !two->data &&
> + S_ISREG(one->mode) && S_ISREG(two->mode) &&
> + !DIFF_OPT_TST(o, BINARY)) {
> + if (!hashcmp(one->sha1, two->sha1)) {
> + if (must_show_header)
> + fprintf(o->file, "%s", header.buf);
> + goto free_ab_and_return;
> + }
> + fprintf(o->file, "%s", header.buf);
> + fprintf(o->file, "%sBinary files %s and %s differ\n",
> + line_prefix, lbl[0], lbl[1]);
> + goto free_ab_and_return;
> + }
A tangent.
I think one and two can point at the same object only when this
filepair is involved in rename/copy. In other words, one and two
with the same <mode,sha1,name> would not be given to this code. And
must-show-header would be set to true long before we get here in
fill-metainfo in such a case.
I think this new code and the original below which you copied this
one from can probably be simplified. It already felt wrong to see
two copies of "fprintf(o->file "%s", header.buf)" and now we have
four of them. Because this is a copy-and-paste of the identical
logic from below, I do not want you to attempt fixing this tangent
in this patch, though.
Thanks.
> if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
> die("unable to read files to diff");
> /* Quite common confusing case */
> diff --git a/t/t1050-large.sh b/t/t1050-large.sh
> index 711f22c..b294963 100755
> --- a/t/t1050-large.sh
> +++ b/t/t1050-large.sh
> @@ -116,6 +116,14 @@ test_expect_success 'diff --stat' '
> git diff --stat HEAD^ HEAD
> '
>
> +test_expect_success 'diff' '
> + git diff HEAD^ HEAD
> +'
> +
> +test_expect_success 'diff --cached' '
> + git diff --cached HEAD^
> +'
> +
> test_expect_success 'hash-object' '
> git hash-object large1
> '
next prev parent reply other threads:[~2014-08-14 17:18 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-27 16:47 Git chokes on large file Dale R. Worley
2014-05-28 13:32 ` Duy Nguyen
2014-05-28 17:10 ` Junio C Hamano
2014-05-28 18:18 ` Dale R. Worley
2014-05-28 18:15 ` Dale R. Worley
2014-05-28 18:23 ` David Lang
2014-05-28 18:47 ` Dale R. Worley
2014-05-28 19:05 ` David Lang
2014-05-29 19:12 ` Dale R. Worley
2014-05-28 18:54 ` Junio C Hamano
2014-05-28 19:09 ` David Lang
2014-05-29 12:57 ` [PATCH 1/4] wrapper.c: introduce gentle xmallocz that does not die() Nguyễn Thái Ngọc Duy
2014-05-29 12:57 ` [PATCH 2/4] fsck: do not die when not enough memory to examine a pack entry Nguyễn Thái Ngọc Duy
2014-05-29 12:57 ` [PATCH 3/4] diff.c: allow to pass more flags to diff_populate_filespec Nguyễn Thái Ngọc Duy
2014-05-29 12:57 ` [PATCH 4/4] diff: mark any file larger than core.bigfilethreshold binary Nguyễn Thái Ngọc Duy
2014-06-19 12:27 ` Thomas Braun
2014-06-23 12:18 ` Duy Nguyen
2014-06-23 19:21 ` Thomas Braun
2014-06-24 11:45 ` [PATCH v2 1/4] wrapper.c: introduce gentle xmallocz that does not die() Nguyễn Thái Ngọc Duy
2014-06-24 11:45 ` [PATCH v2 2/4] fsck: do not die when not enough memory to examine a pack entry Nguyễn Thái Ngọc Duy
2014-06-26 18:09 ` Junio C Hamano
2014-06-29 0:40 ` Duy Nguyen
2014-06-24 11:45 ` [PATCH v2 3/4] diff.c: allow to pass more flags to diff_populate_filespec Nguyễn Thái Ngọc Duy
2014-06-24 11:45 ` [PATCH v2 4/4] diff: mark any file larger than core.bigfilethreshold binary Nguyễn Thái Ngọc Duy
2014-06-26 17:55 ` Junio C Hamano
2014-06-27 18:56 ` Thomas Braun
2014-06-29 1:11 ` Duy Nguyen
2014-08-13 10:57 ` [PATCH v3 0/6] Large file improvements Nguyễn Thái Ngọc Duy
2014-08-13 10:57 ` [PATCH v3 1/6] wrapper.c: introduce gentle xmalloc(z) that does not die() Nguyễn Thái Ngọc Duy
2014-08-14 16:38 ` Junio C Hamano
2014-08-13 10:57 ` [PATCH v3 2/6] sha1_file.c: do not die failing to malloc in unpack_compressed_entry Nguyễn Thái Ngọc Duy
2014-08-13 21:13 ` Junio C Hamano
2014-08-13 10:57 ` [PATCH v3 3/6] unpack-objects: continue when fail to malloc due to large objects Nguyễn Thái Ngọc Duy
2014-08-14 16:58 ` Junio C Hamano
2014-08-15 5:24 ` Duy Nguyen
2014-08-13 10:57 ` [PATCH v3 4/6] diff.c: allow to pass more flags to diff_populate_filespec Nguyễn Thái Ngọc Duy
2014-08-13 10:57 ` [PATCH v3 5/6] diff --stat: mark any file larger than core.bigfilethreshold binary Nguyễn Thái Ngọc Duy
2014-08-13 19:32 ` Eric Sunshine
2014-08-13 10:57 ` [PATCH v3 6/6] diff: shortcut for diff'ing two binary SHA-1 objects Nguyễn Thái Ngọc Duy
2014-08-14 17:00 ` Junio C Hamano
2014-08-15 12:11 ` Duy Nguyen
2014-08-14 17:17 ` Junio C Hamano [this message]
2014-08-16 3:08 ` [PATCH v4 0/5] Large file improvements Nguyễn Thái Ngọc Duy
2014-08-16 3:08 ` [PATCH v4 1/5] wrapper.c: introduce gentle xmallocz that does not die() Nguyễn Thái Ngọc Duy
2014-08-16 3:08 ` [PATCH v4 2/5] sha1_file.c: do not die failing to malloc in unpack_compressed_entry Nguyễn Thái Ngọc Duy
2014-08-16 3:08 ` [PATCH v4 3/5] diff.c: allow to pass more flags to diff_populate_filespec Nguyễn Thái Ngọc Duy
2014-08-16 3:08 ` [PATCH v4 4/5] diff --stat: mark any file larger than core.bigfilethreshold binary Nguyễn Thái Ngọc Duy
2014-08-16 3:08 ` [PATCH v4 5/5] diff: shortcut for diff'ing two binary SHA-1 objects Nguyễn Thái Ngọc Duy
2014-05-28 15:05 ` Git chokes on large file Thomas Braun
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