From: Junio C Hamano <gitster@pobox•com>
To: Kirill Smelkov <kirr@mns•spb.ru>
Cc: git@vger•kernel.org
Subject: Re: [PATCH v2 16/19] tree-diff: reuse base str(buf) memory on sub-tree recursion
Date: Mon, 24 Mar 2014 14:43:36 -0700 [thread overview]
Message-ID: <xmqq61n3p913.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <301eb2377e0c5f670ffc26bda085d14dbee4f431.1393257006.git.kirr@mns.spb.ru> (Kirill Smelkov's message of "Mon, 24 Feb 2014 20:21:48 +0400")
Kirill Smelkov <kirr@mns•spb.ru> writes:
> instead of allocating it all the time for every subtree in
> __diff_tree_sha1, let's allocate it once in diff_tree_sha1, and then all
> callee just use it in stacking style, without memory allocations.
>
> This should be faster, and for me this change gives the following
> slight speedups for
>
> git log --raw --no-abbrev --no-renames --format='%H'
>
> navy.git linux.git v3.10..v3.11
>
> before 0.618s 1.903s
> after 0.611s 1.889s
> speedup 1.1% 0.7%
>
> Signed-off-by: Kirill Smelkov <kirr@mns•spb.ru>
> ---
>
> Changes since v1:
>
> - don't need to touch diff.h, as the function we are changing became static.
>
> tree-diff.c | 36 ++++++++++++++++++------------------
> 1 file changed, 18 insertions(+), 18 deletions(-)
>
> diff --git a/tree-diff.c b/tree-diff.c
> index aea0297..c76821d 100644
> --- a/tree-diff.c
> +++ b/tree-diff.c
> @@ -115,7 +115,7 @@ static void show_path(struct strbuf *base, struct diff_options *opt,
> if (recurse) {
> strbuf_addch(base, '/');
> __diff_tree_sha1(t1 ? t1->entry.sha1 : NULL,
> - t2 ? t2->entry.sha1 : NULL, base->buf, opt);
> + t2 ? t2->entry.sha1 : NULL, base, opt);
> }
>
> strbuf_setlen(base, old_baselen);
I was scratching my head for a while, after seeing that there does
not seem to be any *new* code added by this patch in order to
store-away the original length and restore the singleton base buffer
to the original length after using addch/addstr to extend it.
But I see that the code has already been prepared to do this
conversion. I wonder why we didn't do this earlier ;-)
Looks good. Thanks.
> @@ -138,12 +138,10 @@ static void skip_uninteresting(struct tree_desc *t, struct strbuf *base,
> }
>
> static int __diff_tree_sha1(const unsigned char *old, const unsigned char *new,
> - const char *base_str, struct diff_options *opt)
> + struct strbuf *base, struct diff_options *opt)
> {
> struct tree_desc t1, t2;
> void *t1tree, *t2tree;
> - struct strbuf base;
> - int baselen = strlen(base_str);
>
> t1tree = fill_tree_descriptor(&t1, old);
> t2tree = fill_tree_descriptor(&t2, new);
> @@ -151,17 +149,14 @@ static int __diff_tree_sha1(const unsigned char *old, const unsigned char *new,
> /* Enable recursion indefinitely */
> opt->pathspec.recursive = DIFF_OPT_TST(opt, RECURSIVE);
>
> - strbuf_init(&base, PATH_MAX);
> - strbuf_add(&base, base_str, baselen);
> -
> for (;;) {
> int cmp;
>
> if (diff_can_quit_early(opt))
> break;
> if (opt->pathspec.nr) {
> - skip_uninteresting(&t1, &base, opt);
> - skip_uninteresting(&t2, &base, opt);
> + skip_uninteresting(&t1, base, opt);
> + skip_uninteresting(&t2, base, opt);
> }
> if (!t1.size && !t2.size)
> break;
> @@ -173,7 +168,7 @@ static int __diff_tree_sha1(const unsigned char *old, const unsigned char *new,
> if (DIFF_OPT_TST(opt, FIND_COPIES_HARDER) ||
> hashcmp(t1.entry.sha1, t2.entry.sha1) ||
> (t1.entry.mode != t2.entry.mode))
> - show_path(&base, opt, &t1, &t2);
> + show_path(base, opt, &t1, &t2);
>
> update_tree_entry(&t1);
> update_tree_entry(&t2);
> @@ -181,18 +176,17 @@ static int __diff_tree_sha1(const unsigned char *old, const unsigned char *new,
>
> /* t1 < t2 */
> else if (cmp < 0) {
> - show_path(&base, opt, &t1, /*t2=*/NULL);
> + show_path(base, opt, &t1, /*t2=*/NULL);
> update_tree_entry(&t1);
> }
>
> /* t1 > t2 */
> else {
> - show_path(&base, opt, /*t1=*/NULL, &t2);
> + show_path(base, opt, /*t1=*/NULL, &t2);
> update_tree_entry(&t2);
> }
> }
>
> - strbuf_release(&base);
> free(t2tree);
> free(t1tree);
> return 0;
> @@ -209,7 +203,7 @@ static inline int diff_might_be_rename(void)
> !DIFF_FILE_VALID(diff_queued_diff.queue[0]->one);
> }
>
> -static void try_to_follow_renames(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt)
> +static void try_to_follow_renames(const unsigned char *old, const unsigned char *new, struct strbuf *base, struct diff_options *opt)
> {
> struct diff_options diff_opts;
> struct diff_queue_struct *q = &diff_queued_diff;
> @@ -306,13 +300,19 @@ static void try_to_follow_renames(const unsigned char *old, const unsigned char
> q->nr = 1;
> }
>
> -int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt)
> +int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base_str, struct diff_options *opt)
> {
> + struct strbuf base;
> int retval;
>
> - retval = __diff_tree_sha1(old, new, base, opt);
> - if (!*base && DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename())
> - try_to_follow_renames(old, new, base, opt);
> + strbuf_init(&base, PATH_MAX);
> + strbuf_addstr(&base, base_str);
> +
> + retval = __diff_tree_sha1(old, new, &base, opt);
> + if (!*base_str && DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename())
> + try_to_follow_renames(old, new, &base, opt);
> +
> + strbuf_release(&base);
>
> return retval;
> }
next prev parent reply other threads:[~2014-03-24 21:43 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-24 16:21 [PATCH v2 00/19] Multiparent diff tree-walker + combine-diff speedup Kirill Smelkov
2014-02-24 16:21 ` [PATCH 01/19] combine-diff: move show_log_first logic/action out of paths scanning Kirill Smelkov
2014-02-24 16:21 ` [PATCH 02/19] combine-diff: move changed-paths scanning logic into its own function Kirill Smelkov
2014-02-24 16:21 ` [PATCH 03/19] tree-diff: no need to manually verify that there is no mode change for a path Kirill Smelkov
2014-02-24 16:21 ` [PATCH 04/19] tree-diff: no need to pass match to skip_uninteresting() Kirill Smelkov
2014-02-24 16:21 ` [PATCH 05/19] tree-diff: show_tree() is not needed Kirill Smelkov
2014-02-24 16:21 ` [PATCH 06/19] tree-diff: consolidate code for emitting diffs and recursion in one place Kirill Smelkov
2014-02-24 16:21 ` [PATCH 07/19] tree-diff: don't assume compare_tree_entry() returns -1,0,1 Kirill Smelkov
2014-02-24 16:21 ` [PATCH 08/19] tree-diff: move all action-taking code out of compare_tree_entry() Kirill Smelkov
2014-02-24 16:21 ` [PATCH 09/19] tree-diff: rename compare_tree_entry -> tree_entry_pathcmp Kirill Smelkov
2014-02-24 16:21 ` [PATCH 10/19] tree-diff: show_path prototype is not needed anymore Kirill Smelkov
2014-02-24 16:21 ` [PATCH 11/19] tree-diff: simplify tree_entry_pathcmp Kirill Smelkov
2014-03-24 21:25 ` Junio C Hamano
2014-03-25 9:23 ` Kirill Smelkov
2014-02-24 16:21 ` [PATCH 12/19] tree-diff: remove special-case diff-emitting code for empty-tree cases Kirill Smelkov
2014-03-24 21:18 ` Junio C Hamano
2014-03-25 9:20 ` Kirill Smelkov
2014-03-25 17:45 ` Junio C Hamano
2014-03-26 18:32 ` Kirill Smelkov
2014-03-25 22:07 ` Junio C Hamano
2014-02-24 16:21 ` [PATCH 13/19] tree-diff: diff_tree() should now be static Kirill Smelkov
2014-02-24 16:21 ` [PATCH v2 14/19] tree-diff: rework diff_tree interface to be sha1 based Kirill Smelkov
2014-03-24 21:36 ` Junio C Hamano
2014-03-25 9:22 ` Kirill Smelkov
2014-03-25 17:46 ` Junio C Hamano
2014-03-26 19:52 ` Kirill Smelkov
2014-03-26 21:34 ` Junio C Hamano
2014-03-27 14:24 ` Kirill Smelkov
2014-03-27 18:48 ` Junio C Hamano
2014-03-27 19:43 ` Kirill Smelkov
2014-03-28 6:52 ` Johannes Sixt
2014-03-28 17:06 ` Junio C Hamano
2014-03-28 17:46 ` Johannes Sixt
2014-03-28 18:36 ` Junio C Hamano
2014-03-28 19:08 ` Johannes Sixt
2014-03-28 19:27 ` Junio C Hamano
2014-02-24 16:21 ` [PATCH 15/19] tree-diff: no need to call "full" diff_tree_sha1 from show_path() Kirill Smelkov
2014-03-27 14:21 ` Kirill Smelkov
2014-02-24 16:21 ` [PATCH v2 16/19] tree-diff: reuse base str(buf) memory on sub-tree recursion Kirill Smelkov
2014-03-24 21:43 ` Junio C Hamano [this message]
2014-03-25 9:23 ` Kirill Smelkov
2014-03-27 14:22 ` Kirill Smelkov
2014-02-24 16:21 ` [PATCH 17/19] Portable alloca for Git Kirill Smelkov
2014-02-28 10:58 ` Thomas Schwinge
2014-02-28 13:44 ` Erik Faye-Lund
2014-02-28 13:50 ` Erik Faye-Lund
2014-02-28 17:00 ` Kirill Smelkov
2014-02-28 17:19 ` Erik Faye-Lund
2014-03-05 9:31 ` Kirill Smelkov
2014-03-24 21:47 ` Junio C Hamano
2014-03-27 14:22 ` Kirill Smelkov
2014-04-09 12:48 ` Kirill Smelkov
2014-04-09 13:01 ` Erik Faye-Lund
2014-04-10 17:30 ` Junio C Hamano
2014-02-24 16:21 ` [PATCH v2 18/19] tree-diff: rework diff_tree() to generate diffs for multiparent cases as well Kirill Smelkov
2014-03-27 14:23 ` Kirill Smelkov
2014-04-04 18:42 ` Junio C Hamano
2014-04-06 21:46 ` Kirill Smelkov
2014-04-07 17:29 ` Junio C Hamano
2014-04-07 20:26 ` Kirill Smelkov
2014-04-07 18:07 ` Junio C Hamano
2014-02-24 16:21 ` [PATCH 19/19] combine-diff: speed it up, by using multiparent diff tree-walker directly Kirill Smelkov
2014-02-24 23:43 ` [PATCH v2 00/19] Multiparent diff tree-walker + combine-diff speedup Duy Nguyen
2014-02-25 10:38 ` Kirill Smelkov
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