git-commit-vandalism/name-rev.c
Linus Torvalds 1f1e895fcc Add "named object array" concept
We've had this notion of a "object_list" for a long time, which eventually
grew a "name" member because some users (notably git-rev-list) wanted to
name each object as it is generated.

That object_list is great for some things, but it isn't all that wonderful
for others, and the "name" member is generally not used by everybody.

This patch splits the users of the object_list array up into two: the
traditional list users, who want the list-like format, and who don't
actually use or want the name. And another class of users that really used
the list as an extensible array, and generally wanted to name the objects.

The patch is fairly straightforward, but it's also biggish. Most of it
really just cleans things up: switching the revision parsing and listing
over to the array makes things like the builtin-diff usage much simpler
(we now see exactly how many members the array has, and we don't get the
objects reversed from the order they were on the command line).

One of the main reasons for doing this at all is that the malloc overhead
of the simple object list was actually pretty high, and the array is just
a lot denser. So this patch brings down memory usage by git-rev-list by
just under 3% (on top of all the other memory use optimizations) on the
mozilla archive.

It does add more lines than it removes, and more importantly, it adds a
whole new infrastructure for maintaining lists of objects, but on the
other hand, the new dynamic array code is pretty obvious. The change to
builtin-diff-tree.c shows a fairly good example of why an array interface
is sometimes more natural, and just much simpler for everybody.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-19 18:45:48 -07:00

254 lines
5.3 KiB
C

#include <stdlib.h>
#include "cache.h"
#include "commit.h"
#include "tag.h"
#include "refs.h"
static const char name_rev_usage[] =
"git-name-rev [--tags] ( --all | --stdin | commitish [commitish...] )\n";
typedef struct rev_name {
const char *tip_name;
int merge_traversals;
int generation;
} rev_name;
static long cutoff = LONG_MAX;
static void name_rev(struct commit *commit,
const char *tip_name, int merge_traversals, int generation,
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->merge_traversals > merge_traversals ||
(name->merge_traversals == merge_traversals &&
name->generation > generation)) {
copy_data:
name->tip_name = tip_name;
name->merge_traversals = merge_traversals;
name->generation = generation;
} else
return;
for (parents = commit->parents;
parents;
parents = parents->next, parent_number++) {
if (parent_number > 1) {
char *new_name = xmalloc(strlen(tip_name)+8);
if (generation > 0)
sprintf(new_name, "%s~%d^%d", tip_name,
generation, parent_number);
else
sprintf(new_name, "%s^%d", tip_name, parent_number);
name_rev(parents->item, new_name,
merge_traversals + 1 , 0, 0);
} else {
name_rev(parents->item, tip_name, merge_traversals,
generation + 1, 0);
}
}
}
static int tags_only = 0;
static int name_ref(const char *path, const unsigned char *sha1)
{
struct object *o = parse_object(sha1);
int deref = 0;
if (tags_only && strncmp(path, "refs/tags/", 10))
return 0;
while (o && o->type == TYPE_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 == TYPE_COMMIT) {
struct commit *commit = (struct commit *)o;
if (!strncmp(path, "refs/heads/", 11))
path = path + 11;
else if (!strncmp(path, "refs/", 5))
path = path + 5;
name_rev(commit, strdup(path), 0, 0, deref);
}
return 0;
}
/* returns a static buffer */
static const char* get_rev_name(struct object *o)
{
static char buffer[1024];
struct rev_name *n;
struct commit *c;
if (o->type != TYPE_COMMIT)
return "undefined";
c = (struct commit *) o;
n = c->util;
if (!n)
return "undefined";
if (!n->generation)
return n->tip_name;
snprintf(buffer, sizeof(buffer), "%s~%d", n->tip_name, n->generation);
return buffer;
}
int main(int argc, char **argv)
{
struct object_array revs = { 0, 0, NULL };
int as_is = 0, all = 0, transform_stdin = 0;
setup_git_directory();
git_config(git_default_config);
if (argc < 2)
usage(name_rev_usage);
for (--argc, ++argv; argc; --argc, ++argv) {
unsigned char sha1[20];
struct object *o;
struct commit *commit;
if (!as_is && (*argv)[0] == '-') {
if (!strcmp(*argv, "--")) {
as_is = 1;
continue;
} else if (!strcmp(*argv, "--tags")) {
tags_only = 1;
continue;
} else if (!strcmp(*argv, "--all")) {
if (argc > 1)
die("Specify either a list, or --all, not both!");
all = 1;
cutoff = 0;
continue;
} else if (!strcmp(*argv, "--stdin")) {
if (argc > 1)
die("Specify either a list, or --stdin, not both!");
transform_stdin = 1;
cutoff = 0;
continue;
}
usage(name_rev_usage);
}
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 != TYPE_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);
}
for_each_ref(name_ref);
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 = "undefined";
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 (!strcmp(name, "undefined"))
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;
for (i = 0; i < obj_allocs; i++)
if (objs[i])
printf("%s %s\n", sha1_to_hex(objs[i]->sha1),
get_rev_name(objs[i]));
} else {
int i;
for (i = 0; i < revs.nr; i++)
printf("%s %s\n",
revs.objects[i].name,
get_rev_name(revs.objects[i].item));
}
return 0;
}