name-rev: Fix non-shortest description

Uwe Kleine-König noticed that under certain circumstances, name-rev
picked a non-optimal tag.  Jeff King analyzed that name-rev only
takes into account the number of merge traversals, and then the
_last_ number in the description.

As an easy way to fix it, use a weighting factor for merge traversals:
A merge traversal is now made 65535 times more expensive than a
first-parent traversal.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Acked-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Johannes Schindelin 2007-08-27 12:37:33 +01:00 коммит произвёл Junio C Hamano
Родитель 2b9232cc23
Коммит ac076c29ae
1 изменённых файлов: 11 добавлений и 10 удалений

Просмотреть файл

@ -11,14 +11,17 @@ static const char name_rev_usage[] =
typedef struct rev_name {
const char *tip_name;
int merge_traversals;
int generation;
int distance;
} rev_name;
static long cutoff = LONG_MAX;
/* How many generations are maximally preferred over _one_ merge traversal? */
#define MERGE_TRAVERSAL_WEIGHT 65535
static void name_rev(struct commit *commit,
const char *tip_name, int merge_traversals, int generation,
const char *tip_name, int generation, int distance,
int deref)
{
struct rev_name *name = (struct rev_name *)commit->util;
@ -45,13 +48,11 @@ static void name_rev(struct commit *commit,
name = xmalloc(sizeof(rev_name));
commit->util = name;
goto copy_data;
} else if (name->merge_traversals > merge_traversals ||
(name->merge_traversals == merge_traversals &&
name->generation > generation)) {
} else if (name->distance > distance) {
copy_data:
name->tip_name = tip_name;
name->merge_traversals = merge_traversals;
name->generation = generation;
name->distance = distance;
} else
return;
@ -74,11 +75,11 @@ copy_data:
sprintf(new_name, "%.*s^%d", len, tip_name,
parent_number);
name_rev(parents->item, new_name,
merge_traversals + 1 , 0, 0);
name_rev(parents->item, new_name, 0,
distance + MERGE_TRAVERSAL_WEIGHT, 0);
} else {
name_rev(parents->item, tip_name, merge_traversals,
generation + 1, 0);
name_rev(parents->item, tip_name, generation + 1,
distance + 1, 0);
}
}
}