[RFC PATCH v2 1/9] diffcore-rename: no point trying to find a match better than exact
- From
Elijah Newren <newren@gmail.com>
- Date
- Nov 20, 2017, 22:19 UTC
- Message-ID
- <20171120221944.15431-2-newren@gmail.com>
- In-Reply-To
- <20171120221944.15431-1-newren@gmail.com>
diffcore_rename() had some code to avoid having destination paths that already had an exact rename detected from being re-checked for other renames. Source paths, however, were re-checked because we wanted to allow the possibility of detecting copies. But if copy detection isn't turned on, then this merely amounts to attempting to find a better-than-exact match, which naturally ends up being an expensive no-op. In particular, copy detection is never turned on by the merge recursive machinery.
In a large repository (~50k files, about 60% of which was java) that had a number of high level directories involved in renames, this cut the time necessary for a cherry-pick down by about 50% (from around 9 minutes to 4.5 minutes).
Signed-off-by: Elijah Newren <newren@gmail.com> --- diffcore-rename.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/diffcore-rename.c b/diffcore-rename.c index 9ca0eaec70..fe37e3b861 100644 --- a/diffcore-rename.c +++ b/diffcore-rename.c @@ -377,11 +377,10 @@ static void record_if_better(struct diff_score m[], struct diff_score *o) * 1 if we need to disable inexact rename detection; * 2 if we would be under the limit if we were given -C instead of -C -C. */ -static int too_many_rename_candidates(int num_create, +static int too_many_rename_candidates(int num_create, int num_src, struct diff_options *options) { int rename_limit = options->rename_limit; - int num_src = rename_src_nr; int i; options->needed_rename_limit = 0; @@ -446,7 +445,7 @@ void diffcore_rename(struct diff_options *options) struct diff_queue_struct outq; struct diff_score *mx; int i, j, rename_count, skip_unmodified = 0; - int num_create, dst_cnt; + int num_create, dst_cnt, num_src; struct progress *progress = NULL; if (!minimum_score) @@ -512,12 +511,14 @@ void diffcore_rename(struct diff_options *options) * files still remain as options for rename/copies!) */ num_create = (rename_dst_nr - rename_count); + num_src = (detect_rename == DIFF_DETECT_COPY ? + rename_src_nr : rename_src_nr - rename_count); /* All done? */ if (!num_create) goto cleanup; - switch (too_many_rename_candidates(num_create, options)) { + switch (too_many_rename_candidates(num_create, num_src, options)) { case 1: goto cleanup; case 2: @@ -531,7 +532,7 @@ void diffcore_rename(struct diff_options *options) if (options->show_rename_progress) { progress = start_delayed_progress( _("Performing inexact rename detection"), - (uint64_t)rename_dst_nr * (uint64_t)rename_src_nr); + (uint64_t)num_create * (uint64_t)num_src); } mx = xcalloc(st_mult(NUM_CANDIDATE_PER_DST, num_create), sizeof(*mx)); @@ -550,6 +551,10 @@ void diffcore_rename(struct diff_options *options) struct diff_filespec *one = rename_src[j].p->one; struct diff_score this_src; + if (one->rename_used && + detect_rename != DIFF_DETECT_COPY) + continue; + if (skip_unmodified && diff_unmodified_pair(rename_src[j].p)) continue; @@ -568,7 +573,7 @@ void diffcore_rename(struct diff_options *options) diff_free_filespec_blob(two); } dst_cnt++; - display_progress(progress, (uint64_t)(i+1)*(uint64_t)rename_src_nr); + display_progress(progress, (uint64_t)dst_cnt*(uint64_t)num_src); } stop_progress(&progress);
-- 2.15.0.323.g31fe956618