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git/send-pack.c
Linus Torvalds 885a86abe2 Shrink "struct object" a bit
This shrinks "struct object" by a small amount, by getting rid of the
"struct type *" pointer and replacing it with a 3-bit bitfield instead.

In addition, we merge the bitfields and the "flags" field, which
incidentally should also remove a useless 4-byte padding from the object
when in 64-bit mode.

Now, our "struct object" is still too damn large, but it's now less
obviously bloated, and of the remaining fields, only the "util" (which is
not used by most things) is clearly something that should be eventually
discarded.

This shrinks the "git-rev-list --all" memory use by about 2.5% on the
kernel archive (and, perhaps more importantly, on the larger mozilla
archive). That may not sound like much, but I suspect it's more on a
64-bit platform.

There are other remaining inefficiencies (the parent lists, for example,
probably have horrible malloc overhead), but this was pretty obvious.

Most of the patch is just changing the comparison of the "type" pointer
from one of the constant string pointers to the appropriate new TYPE_xxx
small integer constant.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-17 18:49:18 -07:00

415 lines
9.2 KiB
C

#include "cache.h"
#include "commit.h"
#include "tag.h"
#include "refs.h"
#include "pkt-line.h"
#include "exec_cmd.h"
static const char send_pack_usage[] =
"git-send-pack [--all] [--exec=git-receive-pack] <remote> [<head>...]\n"
" --all and explicit <head> specification are mutually exclusive.";
static const char *exec = "git-receive-pack";
static int verbose = 0;
static int send_all = 0;
static int force_update = 0;
static int use_thin_pack = 0;
static int is_zero_sha1(const unsigned char *sha1)
{
int i;
for (i = 0; i < 20; i++) {
if (*sha1++)
return 0;
}
return 1;
}
static void exec_pack_objects(void)
{
static const char *args[] = {
"pack-objects",
"--stdout",
NULL
};
execv_git_cmd(args);
die("git-pack-objects exec failed (%s)", strerror(errno));
}
static void exec_rev_list(struct ref *refs)
{
struct ref *ref;
static const char *args[1000];
int i = 0, j;
args[i++] = "rev-list"; /* 0 */
if (use_thin_pack) /* 1 */
args[i++] = "--objects-edge";
else
args[i++] = "--objects";
/* First send the ones we care about most */
for (ref = refs; ref; ref = ref->next) {
if (900 < i)
die("git-rev-list environment overflow");
if (!is_zero_sha1(ref->new_sha1)) {
char *buf = malloc(100);
args[i++] = buf;
snprintf(buf, 50, "%s", sha1_to_hex(ref->new_sha1));
buf += 50;
if (!is_zero_sha1(ref->old_sha1) &&
has_sha1_file(ref->old_sha1)) {
args[i++] = buf;
snprintf(buf, 50, "^%s",
sha1_to_hex(ref->old_sha1));
}
}
}
/* Then a handful of the remainder
* NEEDSWORK: we would be better off if used the newer ones first.
*/
for (ref = refs, j = i + 16;
i < 900 && i < j && ref;
ref = ref->next) {
if (is_zero_sha1(ref->new_sha1) &&
!is_zero_sha1(ref->old_sha1) &&
has_sha1_file(ref->old_sha1)) {
char *buf = malloc(42);
args[i++] = buf;
snprintf(buf, 42, "^%s", sha1_to_hex(ref->old_sha1));
}
}
args[i] = NULL;
execv_git_cmd(args);
die("git-rev-list exec failed (%s)", strerror(errno));
}
static void rev_list(int fd, struct ref *refs)
{
int pipe_fd[2];
pid_t pack_objects_pid;
if (pipe(pipe_fd) < 0)
die("rev-list setup: pipe failed");
pack_objects_pid = fork();
if (!pack_objects_pid) {
dup2(pipe_fd[0], 0);
dup2(fd, 1);
close(pipe_fd[0]);
close(pipe_fd[1]);
close(fd);
exec_pack_objects();
die("pack-objects setup failed");
}
if (pack_objects_pid < 0)
die("pack-objects fork failed");
dup2(pipe_fd[1], 1);
close(pipe_fd[0]);
close(pipe_fd[1]);
close(fd);
exec_rev_list(refs);
}
static int pack_objects(int fd, struct ref *refs)
{
pid_t rev_list_pid;
rev_list_pid = fork();
if (!rev_list_pid) {
rev_list(fd, refs);
die("rev-list setup failed");
}
if (rev_list_pid < 0)
die("rev-list fork failed");
/*
* We don't wait for the rev-list pipeline in the parent:
* we end up waiting for the other end instead
*/
return 0;
}
static void unmark_and_free(struct commit_list *list, unsigned int mark)
{
while (list) {
struct commit_list *temp = list;
temp->item->object.flags &= ~mark;
list = temp->next;
free(temp);
}
}
static int ref_newer(const unsigned char *new_sha1,
const unsigned char *old_sha1)
{
struct object *o;
struct commit *old, *new;
struct commit_list *list, *used;
int found = 0;
/* Both new and old must be commit-ish and new is descendant of
* old. Otherwise we require --force.
*/
o = deref_tag(parse_object(old_sha1), NULL, 0);
if (!o || o->type != TYPE_COMMIT)
return 0;
old = (struct commit *) o;
o = deref_tag(parse_object(new_sha1), NULL, 0);
if (!o || o->type != TYPE_COMMIT)
return 0;
new = (struct commit *) o;
if (parse_commit(new) < 0)
return 0;
used = list = NULL;
commit_list_insert(new, &list);
while (list) {
new = pop_most_recent_commit(&list, 1);
commit_list_insert(new, &used);
if (new == old) {
found = 1;
break;
}
}
unmark_and_free(list, 1);
unmark_and_free(used, 1);
return found;
}
static struct ref *local_refs, **local_tail;
static struct ref *remote_refs, **remote_tail;
static int one_local_ref(const char *refname, const unsigned char *sha1)
{
struct ref *ref;
int len = strlen(refname) + 1;
ref = xcalloc(1, sizeof(*ref) + len);
memcpy(ref->new_sha1, sha1, 20);
memcpy(ref->name, refname, len);
*local_tail = ref;
local_tail = &ref->next;
return 0;
}
static void get_local_heads(void)
{
local_tail = &local_refs;
for_each_ref(one_local_ref);
}
static int receive_status(int in)
{
char line[1000];
int ret = 0;
int len = packet_read_line(in, line, sizeof(line));
if (len < 10 || memcmp(line, "unpack ", 7)) {
fprintf(stderr, "did not receive status back\n");
return -1;
}
if (memcmp(line, "unpack ok\n", 10)) {
fputs(line, stderr);
ret = -1;
}
while (1) {
len = packet_read_line(in, line, sizeof(line));
if (!len)
break;
if (len < 3 ||
(memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
fprintf(stderr, "protocol error: %s\n", line);
ret = -1;
break;
}
if (!memcmp(line, "ok", 2))
continue;
fputs(line, stderr);
ret = -1;
}
return ret;
}
static int send_pack(int in, int out, int nr_refspec, char **refspec)
{
struct ref *ref;
int new_refs;
int ret = 0;
int ask_for_status_report = 0;
int expect_status_report = 0;
/* No funny business with the matcher */
remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, 1);
get_local_heads();
/* Does the other end support the reporting? */
if (server_supports("report-status"))
ask_for_status_report = 1;
/* match them up */
if (!remote_tail)
remote_tail = &remote_refs;
if (match_refs(local_refs, remote_refs, &remote_tail,
nr_refspec, refspec, send_all))
return -1;
if (!remote_refs) {
fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
return 0;
}
/*
* Finally, tell the other end!
*/
new_refs = 0;
for (ref = remote_refs; ref; ref = ref->next) {
char old_hex[60], *new_hex;
if (!ref->peer_ref)
continue;
if (!memcmp(ref->old_sha1, ref->peer_ref->new_sha1, 20)) {
if (verbose)
fprintf(stderr, "'%s': up-to-date\n", ref->name);
continue;
}
/* This part determines what can overwrite what.
* The rules are:
*
* (0) you can always use --force or +A:B notation to
* selectively force individual ref pairs.
*
* (1) if the old thing does not exist, it is OK.
*
* (2) if you do not have the old thing, you are not allowed
* to overwrite it; you would not know what you are losing
* otherwise.
*
* (3) if both new and old are commit-ish, and new is a
* descendant of old, it is OK.
*/
if (!force_update &&
!is_zero_sha1(ref->old_sha1) &&
!ref->force) {
if (!has_sha1_file(ref->old_sha1) ||
!ref_newer(ref->peer_ref->new_sha1,
ref->old_sha1)) {
/* We do not have the remote ref, or
* we know that the remote ref is not
* an ancestor of what we are trying to
* push. Either way this can be losing
* commits at the remote end and likely
* we were not up to date to begin with.
*/
error("remote '%s' is not a strict "
"subset of local ref '%s'. "
"maybe you are not up-to-date and "
"need to pull first?",
ref->name,
ref->peer_ref->name);
ret = -2;
continue;
}
}
memcpy(ref->new_sha1, ref->peer_ref->new_sha1, 20);
if (is_zero_sha1(ref->new_sha1)) {
error("cannot happen anymore");
ret = -3;
continue;
}
new_refs++;
strcpy(old_hex, sha1_to_hex(ref->old_sha1));
new_hex = sha1_to_hex(ref->new_sha1);
if (ask_for_status_report) {
packet_write(out, "%s %s %s%c%s",
old_hex, new_hex, ref->name, 0,
"report-status");
ask_for_status_report = 0;
expect_status_report = 1;
}
else
packet_write(out, "%s %s %s",
old_hex, new_hex, ref->name);
fprintf(stderr, "updating '%s'", ref->name);
if (strcmp(ref->name, ref->peer_ref->name))
fprintf(stderr, " using '%s'", ref->peer_ref->name);
fprintf(stderr, "\n from %s\n to %s\n", old_hex, new_hex);
}
packet_flush(out);
if (new_refs)
pack_objects(out, remote_refs);
close(out);
if (expect_status_report) {
if (receive_status(in))
ret = -4;
}
if (!new_refs && ret == 0)
fprintf(stderr, "Everything up-to-date\n");
return ret;
}
int main(int argc, char **argv)
{
int i, nr_heads = 0;
char *dest = NULL;
char **heads = NULL;
int fd[2], ret;
pid_t pid;
setup_git_directory();
git_config(git_default_config);
argv++;
for (i = 1; i < argc; i++, argv++) {
char *arg = *argv;
if (*arg == '-') {
if (!strncmp(arg, "--exec=", 7)) {
exec = arg + 7;
continue;
}
if (!strcmp(arg, "--all")) {
send_all = 1;
continue;
}
if (!strcmp(arg, "--force")) {
force_update = 1;
continue;
}
if (!strcmp(arg, "--verbose")) {
verbose = 1;
continue;
}
if (!strcmp(arg, "--thin")) {
use_thin_pack = 1;
continue;
}
usage(send_pack_usage);
}
if (!dest) {
dest = arg;
continue;
}
heads = argv;
nr_heads = argc - i;
break;
}
if (!dest)
usage(send_pack_usage);
if (heads && send_all)
usage(send_pack_usage);
pid = git_connect(fd, dest, exec);
if (pid < 0)
return 1;
ret = send_pack(fd[0], fd[1], nr_heads, heads);
close(fd[0]);
close(fd[1]);
finish_connect(pid);
return ret;
}