git/builtin-name-rev.c
Junio C Hamano da2478dbb0 describe --always: fall back to showing an abbreviated object name
Some callers may find it useful if "git describe" always gave back a
string that can be used as a shorter name for a commit object, rather than
checking its exit status (while squelching its error message, which could
potentially talk about more grave errors that should not be squelched) and
implementing a fallback themselves.

This teaches describe/name-rev a new option, --always, to use an
abbreviated object name when no tags or refs to use is found.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-03-03 00:52:17 -08:00

295 lines
6.9 KiB
C

#include "builtin.h"
#include "cache.h"
#include "commit.h"
#include "tag.h"
#include "refs.h"
#include "parse-options.h"
#define CUTOFF_DATE_SLOP 86400 /* one day */
typedef struct rev_name {
const char *tip_name;
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 generation, int distance,
int deref)
{
struct rev_name *name = (struct rev_name *)commit->util;
struct commit_list *parents;
int parent_number = 1;
if (!commit->object.parsed)
parse_commit(commit);
if (commit->date < cutoff)
return;
if (deref) {
char *new_name = xmalloc(strlen(tip_name)+3);
strcpy(new_name, tip_name);
strcat(new_name, "^0");
tip_name = new_name;
if (generation)
die("generation: %d, but deref?", generation);
}
if (name == NULL) {
name = xmalloc(sizeof(rev_name));
commit->util = name;
goto copy_data;
} else if (name->distance > distance) {
copy_data:
name->tip_name = tip_name;
name->generation = generation;
name->distance = distance;
} else
return;
for (parents = commit->parents;
parents;
parents = parents->next, parent_number++) {
if (parent_number > 1) {
int len = strlen(tip_name);
char *new_name = xmalloc(len +
1 + decimal_length(generation) + /* ~<n> */
1 + 2 + /* ^NN */
1);
if (len > 2 && !strcmp(tip_name + len - 2, "^0"))
len -= 2;
if (generation > 0)
sprintf(new_name, "%.*s~%d^%d", len, tip_name,
generation, parent_number);
else
sprintf(new_name, "%.*s^%d", len, tip_name,
parent_number);
name_rev(parents->item, new_name, 0,
distance + MERGE_TRAVERSAL_WEIGHT, 0);
} else {
name_rev(parents->item, tip_name, generation + 1,
distance + 1, 0);
}
}
}
struct name_ref_data {
int tags_only;
int name_only;
const char *ref_filter;
};
static int name_ref(const char *path, const unsigned char *sha1, int flags, void *cb_data)
{
struct object *o = parse_object(sha1);
struct name_ref_data *data = cb_data;
int deref = 0;
if (data->tags_only && prefixcmp(path, "refs/tags/"))
return 0;
if (data->ref_filter && fnmatch(data->ref_filter, path, 0))
return 0;
while (o && o->type == OBJ_TAG) {
struct tag *t = (struct tag *) o;
if (!t->tagged)
break; /* broken repository */
o = parse_object(t->tagged->sha1);
deref = 1;
}
if (o && o->type == OBJ_COMMIT) {
struct commit *commit = (struct commit *)o;
if (!prefixcmp(path, "refs/heads/"))
path = path + 11;
else if (data->tags_only
&& data->name_only
&& !prefixcmp(path, "refs/tags/"))
path = path + 10;
else if (!prefixcmp(path, "refs/"))
path = path + 5;
name_rev(commit, xstrdup(path), 0, 0, deref);
}
return 0;
}
/* returns a static buffer */
static const char *get_rev_name(const struct object *o)
{
static char buffer[1024];
struct rev_name *n;
struct commit *c;
if (o->type != OBJ_COMMIT)
return NULL;
c = (struct commit *) o;
n = c->util;
if (!n)
return NULL;
if (!n->generation)
return n->tip_name;
else {
int len = strlen(n->tip_name);
if (len > 2 && !strcmp(n->tip_name + len - 2, "^0"))
len -= 2;
snprintf(buffer, sizeof(buffer), "%.*s~%d", len, n->tip_name,
n->generation);
return buffer;
}
}
static void show_name(const struct object *obj,
const char *caller_name,
int always, int allow_undefined, int name_only)
{
const char *name;
const unsigned char *sha1 = obj->sha1;
if (!name_only)
printf("%s ", caller_name ? caller_name : sha1_to_hex(sha1));
name = get_rev_name(obj);
if (name)
printf("%s\n", name);
else if (allow_undefined)
printf("undefined\n");
else if (always)
printf("%s\n", find_unique_abbrev(sha1, DEFAULT_ABBREV));
else
die("cannot describe '%s'", sha1_to_hex(sha1));
}
static char const * const name_rev_usage[] = {
"git-name-rev [options] ( --all | --stdin | <commit>... )",
NULL
};
int cmd_name_rev(int argc, const char **argv, const char *prefix)
{
struct object_array revs = { 0, 0, NULL };
int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0;
struct name_ref_data data = { 0, 0, NULL };
struct option opts[] = {
OPT_BOOLEAN(0, "name-only", &data.name_only, "print only names (no SHA-1)"),
OPT_BOOLEAN(0, "tags", &data.tags_only, "only use tags to name the commits"),
OPT_STRING(0, "refs", &data.ref_filter, "pattern",
"only use refs matching <pattern>"),
OPT_GROUP(""),
OPT_BOOLEAN(0, "all", &all, "list all commits reachable from all refs"),
OPT_BOOLEAN(0, "stdin", &transform_stdin, "read from stdin"),
OPT_BOOLEAN(0, "undefined", &allow_undefined, "allow to print `undefined` names"),
OPT_BOOLEAN(0, "always", &always,
"show abbreviated commit object as fallback"),
OPT_END(),
};
git_config(git_default_config);
argc = parse_options(argc, argv, opts, name_rev_usage, 0);
if (!!all + !!transform_stdin + !!argc > 1) {
error("Specify either a list, or --all, not both!");
usage_with_options(name_rev_usage, opts);
}
if (all || transform_stdin)
cutoff = 0;
for (; argc; argc--, argv++) {
unsigned char sha1[20];
struct object *o;
struct commit *commit;
if (get_sha1(*argv, sha1)) {
fprintf(stderr, "Could not get sha1 for %s. Skipping.\n",
*argv);
continue;
}
o = deref_tag(parse_object(sha1), *argv, 0);
if (!o || o->type != OBJ_COMMIT) {
fprintf(stderr, "Could not get commit for %s. Skipping.\n",
*argv);
continue;
}
commit = (struct commit *)o;
if (cutoff > commit->date)
cutoff = commit->date;
add_object_array((struct object *)commit, *argv, &revs);
}
if (cutoff)
cutoff = cutoff - CUTOFF_DATE_SLOP;
for_each_ref(name_ref, &data);
if (transform_stdin) {
char buffer[2048];
char *p, *p_start;
while (!feof(stdin)) {
int forty = 0;
p = fgets(buffer, sizeof(buffer), stdin);
if (!p)
break;
for (p_start = p; *p; p++) {
#define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f'))
if (!ishex(*p))
forty = 0;
else if (++forty == 40 &&
!ishex(*(p+1))) {
unsigned char sha1[40];
const char *name = NULL;
char c = *(p+1);
forty = 0;
*(p+1) = 0;
if (!get_sha1(p - 39, sha1)) {
struct object *o =
lookup_object(sha1);
if (o)
name = get_rev_name(o);
}
*(p+1) = c;
if (!name)
continue;
fwrite(p_start, p - p_start + 1, 1, stdout);
printf(" (%s)", name);
p_start = p + 1;
}
}
/* flush */
if (p_start != p)
fwrite(p_start, p - p_start, 1, stdout);
}
} else if (all) {
int i, max;
max = get_max_object_index();
for (i = 0; i < max; i++)
show_name(get_indexed_object(i), NULL,
always, allow_undefined, data.name_only);
} else {
int i;
for (i = 0; i < revs.nr; i++)
show_name(revs.objects[i].item, revs.objects[i].name,
always, allow_undefined, data.name_only);
}
return 0;
}