Merge branch 'jc/name-rev-lw-tag' into maint

"git describe --contains" penalized light-weight tags so much that
they were almost never considered.  Instead, give them about the
same chance to be considered as an annotated tag that is the same
age as the underlying commit would.

* jc/name-rev-lw-tag:
  name-rev: favor describing with tags and use committer date to tiebreak
  name-rev: refactor logic to see if a new candidate is a better name
This commit is contained in:
Junio C Hamano 2017-06-24 15:29:27 -07:00
commit e8d9d8b0bd
2 changed files with 53 additions and 8 deletions

View File

@ -13,6 +13,7 @@ typedef struct rev_name {
unsigned long taggerdate;
int generation;
int distance;
int from_tag;
} rev_name;
static long cutoff = LONG_MAX;
@ -20,9 +21,47 @@ static long cutoff = LONG_MAX;
/* How many generations are maximally preferred over _one_ merge traversal? */
#define MERGE_TRAVERSAL_WEIGHT 65535
static int is_better_name(struct rev_name *name,
const char *tip_name,
unsigned long taggerdate,
int generation,
int distance,
int from_tag)
{
/*
* When comparing names based on tags, prefer names
* based on the older tag, even if it is farther away.
*/
if (from_tag && name->from_tag)
return (name->taggerdate > taggerdate ||
(name->taggerdate == taggerdate &&
name->distance > distance));
/*
* We know that at least one of them is a non-tag at this point.
* favor a tag over a non-tag.
*/
if (name->from_tag != from_tag)
return from_tag;
/*
* We are now looking at two non-tags. Tiebreak to favor
* shorter hops.
*/
if (name->distance != distance)
return name->distance > distance;
/* ... or tiebreak to favor older date */
if (name->taggerdate != taggerdate)
return name->taggerdate > taggerdate;
/* keep the current one if we cannot decide */
return 0;
}
static void name_rev(struct commit *commit,
const char *tip_name, unsigned long taggerdate,
int generation, int distance,
int generation, int distance, int from_tag,
int deref)
{
struct rev_name *name = (struct rev_name *)commit->util;
@ -46,14 +85,14 @@ static void name_rev(struct commit *commit,
name = xmalloc(sizeof(rev_name));
commit->util = name;
goto copy_data;
} else if (name->taggerdate > taggerdate ||
(name->taggerdate == taggerdate &&
name->distance > distance)) {
} else if (is_better_name(name, tip_name, taggerdate,
generation, distance, from_tag)) {
copy_data:
name->tip_name = tip_name;
name->taggerdate = taggerdate;
name->generation = generation;
name->distance = distance;
name->from_tag = from_tag;
} else {
free(to_free);
return;
@ -75,10 +114,12 @@ copy_data:
parent_number);
name_rev(parents->item, new_name, taggerdate, 0,
distance + MERGE_TRAVERSAL_WEIGHT, 0);
distance + MERGE_TRAVERSAL_WEIGHT,
from_tag, 0);
} else {
name_rev(parents->item, tip_name, taggerdate,
generation + 1, distance + 1, 0);
generation + 1, distance + 1,
from_tag, 0);
}
}
}
@ -209,9 +250,13 @@ static int name_ref(const char *path, const struct object_id *oid, int flags, vo
}
if (o && o->type == OBJ_COMMIT) {
struct commit *commit = (struct commit *)o;
int from_tag = starts_with(path, "refs/tags/");
if (taggerdate == ULONG_MAX)
taggerdate = ((struct commit *)o)->date;
path = name_ref_abbrev(path, can_abbreviate_output);
name_rev(commit, xstrdup(path), taggerdate, 0, 0, deref);
name_rev(commit, xstrdup(path), taggerdate, 0, 0,
from_tag, deref);
}
return 0;
}

View File

@ -399,7 +399,7 @@ cat > expect <<\EOF
| |
| | Merge branch 'side'
| |
| * commit side
| * commit tags/side-2
| | Author: A U Thor <author@example.com>
| |
| | side-2