From: Junio C Hamano <gitster@pobox.com>
To: "Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com>
Cc: git@vger.kernel.org, Derrick Stolee <dstolee@microsoft.com>,
Jonathan Tan <jonathantanmy@google.com>,
Taylor Blau <me@ttaylorr.com>, Jeff King <peff@peff.net>,
Elijah Newren <newren@gmail.com>,
Derrick Stolee <stolee@gmail.com>
Subject: Re: [PATCH v3 2/5] diffcore-rename: compute basenames of all source and dest candidates
Date: Fri, 12 Feb 2021 17:32:59 -0800 [thread overview]
Message-ID: <xmqqy2fsu4z8.fsf@gitster.c.googlers.com> (raw)
In-Reply-To: <4fff9b1ff57b62587b1cbec2031f96199a214702.1612970140.git.gitgitgadget@gmail.com> (Elijah Newren via GitGitGadget's message of "Wed, 10 Feb 2021 15:15:37 +0000")
"Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com> writes:
> +MAYBE_UNUSED
> +static int find_basename_matches(struct diff_options *options,
> + int minimum_score,
> + int num_src)
> +{
> + int i;
> + struct strintmap sources;
> + struct strintmap dests;
> +
> + /* Create maps of basename -> fullname(s) for sources and dests */
> + strintmap_init_with_options(&sources, -1, NULL, 0);
> + strintmap_init_with_options(&dests, -1, NULL, 0);
> + for (i = 0; i < num_src; ++i) {
> + char *filename = rename_src[i].p->one->path;
> + const char *base;
> +
> + /* exact renames removed in remove_unneeded_paths_from_src() */
> + assert(!rename_src[i].p->one->rename_used);
> +
> + /* Record index within rename_src (i) if basename is unique */
> + base = get_basename(filename);
> + if (strintmap_contains(&sources, base))
> + strintmap_set(&sources, base, -1);
> + else
> + strintmap_set(&sources, base, i);
> + }
> + for (i = 0; i < rename_dst_nr; ++i) {
> + char *filename = rename_dst[i].p->two->path;
> + const char *base;
> +
> + if (rename_dst[i].is_rename)
> + continue; /* involved in exact match already. */
> +
> + /* Record index within rename_dst (i) if basename is unique */
> + base = get_basename(filename);
> + if (strintmap_contains(&dests, base))
> + strintmap_set(&dests, base, -1);
> + else
> + strintmap_set(&dests, base, i);
> + }
> +
> + /* TODO: Make use of basenames source and destination basenames */
;-)
So at this point sources and dests can be used to quickly look up,
given a filename, if there is a single src among all sources, and a
single dst among all dests, that have the filename.
I wonder if the second loop over destinations can be "optimized"
further by using the sources map, though. The reason you quash
entries with -1 when you see second instance of the same name is
because you intend to limit the heuristics only to a uniquely named
file among the removed files going to a uniquely named file among
the added files, right? So even if a name is unique among dests,
if that name has duplicates on the source side, there is no point
recording its location. i.e.
/* record index within dst if it is unique in both dst and src */
base = get_basename(filename);
if (strintmap_contains(&sources, base) ||
strintmap_contains(&dests, base))
strintmap_set(&dests, base, -1);
else
strintmap_set(&dests, base, i);
perhaps?
I guess it depends on what actually will be written in this "TODO"
space how effective such a change would be. Presumably, you'd
iterate over &sources while skipping entries that record -1, to
learn (basename, i), and use the basename found there to consult
&dests to see if it yields a non-negative integer j, to notice that
rename_src[i] is a good candidate to match rename_dst[j]. If that
is the case, then such a change won't help as an optimization at
all, as we'd need to consult &dests map with the basename anyway,
so let's scratch the above idea.
In any case, after we walk over rename_src[] and rename_dst[] once,
the number of entries in &sources would be smaller than rename_src[]
so iterating over &sources, hunting for entries that record
non-negative index into rename_src[] would hopefully be cheaper than
the naive loop we've been working with. I like the idea of using the
strintmap for this part of the code.
Thanks.
> + strintmap_clear(&sources);
> + strintmap_clear(&dests);
> +
> + return 0;
> +}
> +
> #define NUM_CANDIDATE_PER_DST 4
> static void record_if_better(struct diff_score m[], struct diff_score *o)
> {
next prev parent reply other threads:[~2021-02-13 1:34 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-06 22:52 [PATCH 0/3] Optimization batch 7: use file basenames to guide rename detection Elijah Newren via GitGitGadget
2021-02-06 22:52 ` [PATCH 1/3] diffcore-rename: compute basenames of all source and dest candidates Elijah Newren via GitGitGadget
2021-02-06 22:52 ` [PATCH 2/3] diffcore-rename: complete find_basename_matches() Elijah Newren via GitGitGadget
2021-02-06 22:52 ` [PATCH 3/3] diffcore-rename: guide inexact rename detection based on basenames Elijah Newren via GitGitGadget
2021-02-07 14:38 ` Derrick Stolee
2021-02-07 19:51 ` Junio C Hamano
2021-02-08 8:38 ` Elijah Newren
2021-02-08 11:43 ` Derrick Stolee
2021-02-08 16:25 ` Elijah Newren
2021-02-08 17:37 ` Junio C Hamano
2021-02-08 22:00 ` Elijah Newren
2021-02-08 23:43 ` Junio C Hamano
2021-02-08 23:52 ` Elijah Newren
2021-02-08 8:27 ` Elijah Newren
2021-02-08 11:31 ` Derrick Stolee
2021-02-08 16:09 ` Elijah Newren
2021-02-07 5:19 ` [PATCH 0/3] Optimization batch 7: use file basenames to guide rename detection Junio C Hamano
2021-02-07 6:05 ` Elijah Newren
2021-02-09 11:32 ` [PATCH v2 0/4] " Elijah Newren via GitGitGadget
2021-02-09 11:32 ` [PATCH v2 1/4] diffcore-rename: compute basenames of all source and dest candidates Elijah Newren via GitGitGadget
2021-02-09 13:17 ` Derrick Stolee
2021-02-09 16:56 ` Elijah Newren
2021-02-09 17:02 ` Derrick Stolee
2021-02-09 17:42 ` Elijah Newren
2021-02-09 11:32 ` [PATCH v2 2/4] diffcore-rename: complete find_basename_matches() Elijah Newren via GitGitGadget
2021-02-09 13:25 ` Derrick Stolee
2021-02-09 17:17 ` Elijah Newren
2021-02-09 17:34 ` Derrick Stolee
2021-02-09 11:32 ` [PATCH v2 3/4] diffcore-rename: guide inexact rename detection based on basenames Elijah Newren via GitGitGadget
2021-02-09 13:33 ` Derrick Stolee
2021-02-09 17:41 ` Elijah Newren
2021-02-09 18:59 ` Junio C Hamano
2021-02-09 11:32 ` [PATCH v2 4/4] gitdiffcore doc: mention new preliminary step for rename detection Elijah Newren via GitGitGadget
2021-02-09 12:59 ` Derrick Stolee
2021-02-09 17:03 ` Junio C Hamano
2021-02-09 17:44 ` Elijah Newren
2021-02-10 15:15 ` [PATCH v3 0/5] Optimization batch 7: use file basenames to guide " Elijah Newren via GitGitGadget
2021-02-10 15:15 ` [PATCH v3 1/5] t4001: add a test comparing basename similarity and content similarity Elijah Newren via GitGitGadget
2021-02-13 1:15 ` Junio C Hamano
2021-02-13 4:50 ` Elijah Newren
2021-02-13 23:56 ` Junio C Hamano
2021-02-14 1:24 ` Elijah Newren
2021-02-14 1:32 ` Junio C Hamano
2021-02-14 3:14 ` Elijah Newren
2021-02-10 15:15 ` [PATCH v3 2/5] diffcore-rename: compute basenames of all source and dest candidates Elijah Newren via GitGitGadget
2021-02-13 1:32 ` Junio C Hamano [this message]
2021-02-10 15:15 ` [PATCH v3 3/5] diffcore-rename: complete find_basename_matches() Elijah Newren via GitGitGadget
2021-02-13 1:48 ` Junio C Hamano
2021-02-13 18:34 ` Elijah Newren
2021-02-13 23:55 ` Junio C Hamano
2021-02-14 3:08 ` Elijah Newren
2021-02-10 15:15 ` [PATCH v3 4/5] diffcore-rename: guide inexact rename detection based on basenames Elijah Newren via GitGitGadget
2021-02-13 1:49 ` Junio C Hamano
2021-02-10 15:15 ` [PATCH v3 5/5] gitdiffcore doc: mention new preliminary step for rename detection Elijah Newren via GitGitGadget
2021-02-10 16:41 ` Junio C Hamano
2021-02-10 17:20 ` Elijah Newren
2021-02-11 8:15 ` [PATCH v4 0/6] Optimization batch 7: use file basenames to guide " Elijah Newren via GitGitGadget
2021-02-11 8:15 ` [PATCH v4 1/6] t4001: add a test comparing basename similarity and content similarity Elijah Newren via GitGitGadget
2021-02-11 8:15 ` [PATCH v4 2/6] diffcore-rename: compute basenames of all source and dest candidates Elijah Newren via GitGitGadget
2021-02-11 8:15 ` [PATCH v4 3/6] diffcore-rename: complete find_basename_matches() Elijah Newren via GitGitGadget
2021-02-11 8:15 ` [PATCH v4 4/6] diffcore-rename: guide inexact rename detection based on basenames Elijah Newren via GitGitGadget
2021-02-11 8:15 ` [PATCH v4 5/6] gitdiffcore doc: mention new preliminary step for rename detection Elijah Newren via GitGitGadget
2021-02-11 8:15 ` [PATCH v4 6/6] merge-ort: call diffcore_rename() directly Elijah Newren via GitGitGadget
2021-02-13 1:53 ` [PATCH v4 0/6] Optimization batch 7: use file basenames to guide rename detection Junio C Hamano
2021-02-14 7:51 ` [PATCH v5 " Elijah Newren via GitGitGadget
2021-02-14 7:51 ` [PATCH v5 1/6] t4001: add a test comparing basename similarity and content similarity Elijah Newren via GitGitGadget
2021-02-14 7:51 ` [PATCH v5 2/6] diffcore-rename: compute basenames of source and dest candidates Elijah Newren via GitGitGadget
2021-02-14 7:51 ` [PATCH v5 3/6] diffcore-rename: complete find_basename_matches() Elijah Newren via GitGitGadget
2021-02-14 7:51 ` [PATCH v5 4/6] diffcore-rename: guide inexact rename detection based on basenames Elijah Newren via GitGitGadget
2021-02-14 7:51 ` [PATCH v5 5/6] gitdiffcore doc: mention new preliminary step for rename detection Elijah Newren via GitGitGadget
2021-02-14 7:51 ` [PATCH v5 6/6] merge-ort: call diffcore_rename() directly Elijah Newren via GitGitGadget
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