Revision d699676dda5fdf0996601006c3bac2a9c077a862 authored by Linus Torvalds on 10 August 2007, 19:31:20 UTC, committed by Junio C Hamano on 10 August 2007, 21:00:25 UTC
This trivially optimizes the two-way merge case of git-read-tree too, which affects switching branches. When you have tons and tons of files in your repository, but there are only small differences in the branches (maybe just a couple of files changed), the biggest cost of the branch switching was actually just the index calculations. This fixes it (timings for switching between the "testing" and "master" branches in the 100,000 file testing-repo-from-hell, where the branches only differ in one small file). Before: [torvalds@woody bummer]$ time git checkout master real 0m9.919s user 0m8.461s sys 0m0.264s After: [torvalds@woody bummer]$ time git checkout testing real 0m0.576s user 0m0.348s sys 0m0.228s so it's easily an order of magnitude different. This concludes the series. I think we could/should do the three-way merge too (to speed up merges), but I'm lazy. Somebody else can do it. The rule is very simple: you need to remove the old entry if: - you want to remove the file entirely - you replace it with a "merge conflict" entry (ie a non-stage-0 entry) and you can avoid removing it if you either - keep the old one - or resolve it to a new one. and these rules should all be valid for the three-way case too. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 288f072
builtin-pack-refs.c
#include "builtin.h"
#include "cache.h"
#include "refs.h"
#include "object.h"
#include "tag.h"
static const char builtin_pack_refs_usage[] =
"git-pack-refs [--all] [--prune | --no-prune]";
struct ref_to_prune {
struct ref_to_prune *next;
unsigned char sha1[20];
char name[FLEX_ARRAY];
};
#define PACK_REFS_PRUNE 0x0001
#define PACK_REFS_ALL 0x0002
struct pack_refs_cb_data {
unsigned int flags;
struct ref_to_prune *ref_to_prune;
FILE *refs_file;
};
static int do_not_prune(int flags)
{
/* If it is already packed or if it is a symref,
* do not prune it.
*/
return (flags & (REF_ISSYMREF|REF_ISPACKED));
}
static int handle_one_ref(const char *path, const unsigned char *sha1,
int flags, void *cb_data)
{
struct pack_refs_cb_data *cb = cb_data;
int is_tag_ref;
/* Do not pack the symbolic refs */
if ((flags & REF_ISSYMREF))
return 0;
is_tag_ref = !prefixcmp(path, "refs/tags/");
/* ALWAYS pack refs that were already packed or are tags */
if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref && !(flags & REF_ISPACKED))
return 0;
fprintf(cb->refs_file, "%s %s\n", sha1_to_hex(sha1), path);
if (is_tag_ref) {
struct object *o = parse_object(sha1);
if (o->type == OBJ_TAG) {
o = deref_tag(o, path, 0);
if (o)
fprintf(cb->refs_file, "^%s\n",
sha1_to_hex(o->sha1));
}
}
if ((cb->flags & PACK_REFS_PRUNE) && !do_not_prune(flags)) {
int namelen = strlen(path) + 1;
struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
hashcpy(n->sha1, sha1);
strcpy(n->name, path);
n->next = cb->ref_to_prune;
cb->ref_to_prune = n;
}
return 0;
}
/* make sure nobody touched the ref, and unlink */
static void prune_ref(struct ref_to_prune *r)
{
struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
if (lock) {
unlink(git_path("%s", r->name));
unlock_ref(lock);
}
}
static void prune_refs(struct ref_to_prune *r)
{
while (r) {
prune_ref(r);
r = r->next;
}
}
static struct lock_file packed;
static int pack_refs(unsigned int flags)
{
int fd;
struct pack_refs_cb_data cbdata;
memset(&cbdata, 0, sizeof(cbdata));
cbdata.flags = flags;
fd = hold_lock_file_for_update(&packed, git_path("packed-refs"), 1);
cbdata.refs_file = fdopen(fd, "w");
if (!cbdata.refs_file)
die("unable to create ref-pack file structure (%s)",
strerror(errno));
/* perhaps other traits later as well */
fprintf(cbdata.refs_file, "# pack-refs with: peeled \n");
for_each_ref(handle_one_ref, &cbdata);
if (ferror(cbdata.refs_file))
die("failed to write ref-pack file");
if (fflush(cbdata.refs_file) || fsync(fd) || fclose(cbdata.refs_file))
die("failed to write ref-pack file (%s)", strerror(errno));
if (commit_lock_file(&packed) < 0)
die("unable to overwrite old ref-pack file (%s)", strerror(errno));
if (cbdata.flags & PACK_REFS_PRUNE)
prune_refs(cbdata.ref_to_prune);
return 0;
}
int cmd_pack_refs(int argc, const char **argv, const char *prefix)
{
int i;
unsigned int flags;
flags = PACK_REFS_PRUNE;
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (!strcmp(arg, "--prune")) {
flags |= PACK_REFS_PRUNE; /* now the default */
continue;
}
if (!strcmp(arg, "--no-prune")) {
flags &= ~PACK_REFS_PRUNE;
continue;
}
if (!strcmp(arg, "--all")) {
flags |= PACK_REFS_ALL;
continue;
}
/* perhaps other parameters later... */
break;
}
if (i != argc)
usage(builtin_pack_refs_usage);
return pack_refs(flags);
}
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...