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#include "cache.h"
#include "commit.h"
#include "tag.h"
#include "refs.h"
#define SEEN (1u << 0)
static const char describe_usage[] = "git-describe [--all] <committish>*";
static int all = 0; /* Default to annotated tags only */
static int names = 0, allocs = 0;
static struct commit_name {
const struct commit *commit;
char path[];
} **name_array = NULL;
static struct commit_name *match(struct commit *cmit)
{
int i = names;
struct commit_name **p = name_array;
while (i-- > 0) {
struct commit_name *n = *p++;
if (n->commit == cmit)
return n;
}
return NULL;
}
static void add_to_known_names(const char *path, const struct commit *commit)
{
int idx;
int len = strlen(path)+1;
struct commit_name *name = xmalloc(sizeof(struct commit_name) + len);
name->commit = commit;
memcpy(name->path, path, len);
idx = names;
if (idx >= allocs) {
allocs = (idx + 50) * 3 / 2;
name_array = xrealloc(name_array, allocs*sizeof(*name_array));
}
name_array[idx] = name;
names = ++idx;
}
static int get_name(const char *path, const unsigned char *sha1)
{
struct commit *commit = lookup_commit_reference_gently(sha1, 1);
if (!commit)
return 0;
if (!all) {
struct object *object;
if (strncmp(path, "refs/tags/", 10))
return 0;
object = parse_object(sha1);
if (object->type != tag_type)
return 0;
}
add_to_known_names(all ? path : path + 10, commit);
return 0;
}
static int compare_names(const void *_a, const void *_b)
{
struct commit_name *a = *(struct commit_name **)_a;
struct commit_name *b = *(struct commit_name **)_b;
unsigned long a_date = a->commit->date;
unsigned long b_date = b->commit->date;
return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
}
static void describe(struct commit *cmit)
{
struct commit_list *list;
static int initialized = 0;
struct commit_name *n;
if (!initialized) {
initialized = 1;
for_each_ref(get_name);
qsort(name_array, names, sizeof(*name_array), compare_names);
}
n = match(cmit);
if (n) {
printf("%s\n", n->path);
return;
}
list = NULL;
commit_list_insert(cmit, &list);
while (list) {
struct commit *c = pop_most_recent_commit(&list, SEEN);
n = match(c);
if (n) {
printf("%s-g%.8s\n", n->path, sha1_to_hex(cmit->object.sha1));
return;
}
}
}
int main(int argc, char **argv)
{
int i;
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
unsigned char sha1[20];
struct commit *cmit;
if (!strcmp(arg, "--all")) {
all = 1;
continue;
}
if (get_sha1(arg, sha1) < 0)
usage(describe_usage);
cmit = lookup_commit_reference(sha1);
if (!cmit)
usage(describe_usage);
describe(cmit);
}
return 0;
}
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