Revision 9de0834663f28bee9e6b2c4647ed6128241ed26f authored by Linus Torvalds on 17 October 2006, 02:58:54 UTC, committed by Junio C Hamano on 17 October 2006, 04:27:44 UTC
Jim Mayering noticed that xdiff library took insanely long time when comparing files with many identical lines. This was because the hash function used in the library is broken on 64-bit architectures and caused too many collisions. http://thread.gmane.org/gmane.comp.version-control.git/28962/focus=28994 Acked-by: Davide Libenzi <davidel@xmaliserver.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
1 parent 6fe5b7f
describe.c
#include "cache.h"
#include "commit.h"
#include "tag.h"
#include "refs.h"
#define SEEN (1u << 0)
static const char describe_usage[] =
"git-describe [--all] [--tags] [--abbrev=<n>] <committish>*";
static int all = 0; /* Default to annotated tags only */
static int tags = 0; /* But allow any tags if --tags is specified */
static int abbrev = DEFAULT_ABBREV;
static int names = 0, allocs = 0;
static struct commit_name {
const struct commit *commit;
int prio; /* annotated tag = 2, tag = 1, head = 0 */
char path[FLEX_ARRAY]; /* more */
} **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 prio)
{
int idx;
int len = strlen(path)+1;
struct commit_name *name = xmalloc(sizeof(struct commit_name) + len);
name->commit = commit;
name->prio = prio;
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);
struct object *object;
int prio;
if (!commit)
return 0;
object = parse_object(sha1);
/* If --all, then any refs are used.
* If --tags, then any tags are used.
* Otherwise only annotated tags are used.
*/
if (!strncmp(path, "refs/tags/", 10)) {
if (object->type == OBJ_TAG)
prio = 2;
else
prio = 1;
}
else
prio = 0;
if (!all) {
if (!prio)
return 0;
if (!tags && prio < 2)
return 0;
}
add_to_known_names(all ? path + 5 : path + 10, commit, prio);
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;
if (a->prio != b->prio)
return b->prio - a->prio;
return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
}
static void describe(const char *arg, int last_one)
{
unsigned char sha1[20];
struct commit *cmit;
struct commit_list *list;
static int initialized = 0;
struct commit_name *n;
if (get_sha1(arg, sha1))
die("Not a valid object name %s", arg);
cmit = lookup_commit_reference(sha1);
if (!cmit)
die("%s is not a valid '%s' object", arg, commit_type);
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%s\n", n->path,
find_unique_abbrev(cmit->object.sha1, abbrev));
if (!last_one)
clear_commit_marks(cmit, SEEN);
return;
}
}
die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
}
int main(int argc, char **argv)
{
int i;
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (*arg != '-')
break;
else if (!strcmp(arg, "--all"))
all = 1;
else if (!strcmp(arg, "--tags"))
tags = 1;
else if (!strncmp(arg, "--abbrev=", 9)) {
abbrev = strtoul(arg + 9, NULL, 10);
if (abbrev < MINIMUM_ABBREV || 40 <= abbrev)
abbrev = DEFAULT_ABBREV;
}
else
usage(describe_usage);
}
if (i == argc)
describe("HEAD", 1);
else
while (i < argc) {
describe(argv[i], (i == argc - 1));
i++;
}
return 0;
}
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