git/fetch-pack.c
Junio C Hamano dfeff66ed9 revamp git-clone.
This does two things.

 * A new flag --reference can be used to name a local repository
   that is to be used as an alternate.  This is in response to
   an inquiry by James Cloos in the message on the list
   <m3r74ykue7.fsf@lugabout.cloos.reno.nv.us>.

 * A new flag --use-separate-remote stops contaminating local
   branch namespace by upstream branch names.  The upstream
   branch heads are copied in .git/refs/remotes/ instead of
   .git/refs/heads/ and .git/remotes/origin file is set up to
   reflect this as well.  It requires to have fetch/pull update
   to understand .git/refs/remotes by Eric Wong to further
   update the repository cloned this way.

For the former change, git-fetch-pack is taught a new flag --all
to fetch from all the remote heads.  Nobody uses the git-clone-pack
with this change, so we could deprecate the command, but removal
of the command will be left to a separate round.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-20 00:21:10 -08:00

477 lines
10 KiB
C

#include "cache.h"
#include "refs.h"
#include "pkt-line.h"
#include "commit.h"
#include "tag.h"
static int keep_pack;
static int quiet;
static int verbose;
static int fetch_all;
static const char fetch_pack_usage[] =
"git-fetch-pack [--all] [-q] [-v] [-k] [--thin] [--exec=upload-pack] [host:]directory <refs>...";
static const char *exec = "git-upload-pack";
#define COMPLETE (1U << 0)
#define COMMON (1U << 1)
#define COMMON_REF (1U << 2)
#define SEEN (1U << 3)
#define POPPED (1U << 4)
static struct commit_list *rev_list = NULL;
static int non_common_revs = 0, multi_ack = 0, use_thin_pack = 0;
static void rev_list_push(struct commit *commit, int mark)
{
if (!(commit->object.flags & mark)) {
commit->object.flags |= mark;
if (!(commit->object.parsed))
parse_commit(commit);
insert_by_date(commit, &rev_list);
if (!(commit->object.flags & COMMON))
non_common_revs++;
}
}
static int rev_list_insert_ref(const char *path, const unsigned char *sha1)
{
struct object *o = deref_tag(parse_object(sha1), path, 0);
if (o && o->type == commit_type)
rev_list_push((struct commit *)o, SEEN);
return 0;
}
/*
This function marks a rev and its ancestors as common.
In some cases, it is desirable to mark only the ancestors (for example
when only the server does not yet know that they are common).
*/
static void mark_common(struct commit *commit,
int ancestors_only, int dont_parse)
{
if (commit != NULL && !(commit->object.flags & COMMON)) {
struct object *o = (struct object *)commit;
if (!ancestors_only)
o->flags |= COMMON;
if (!(o->flags & SEEN))
rev_list_push(commit, SEEN);
else {
struct commit_list *parents;
if (!ancestors_only && !(o->flags & POPPED))
non_common_revs--;
if (!o->parsed && !dont_parse)
parse_commit(commit);
for (parents = commit->parents;
parents;
parents = parents->next)
mark_common(parents->item, 0, dont_parse);
}
}
}
/*
Get the next rev to send, ignoring the common.
*/
static const unsigned char* get_rev(void)
{
struct commit *commit = NULL;
while (commit == NULL) {
unsigned int mark;
struct commit_list* parents;
if (rev_list == NULL || non_common_revs == 0)
return NULL;
commit = rev_list->item;
if (!(commit->object.parsed))
parse_commit(commit);
commit->object.flags |= POPPED;
if (!(commit->object.flags & COMMON))
non_common_revs--;
parents = commit->parents;
if (commit->object.flags & COMMON) {
/* do not send "have", and ignore ancestors */
commit = NULL;
mark = COMMON | SEEN;
} else if (commit->object.flags & COMMON_REF)
/* send "have", and ignore ancestors */
mark = COMMON | SEEN;
else
/* send "have", also for its ancestors */
mark = SEEN;
while (parents) {
if (!(parents->item->object.flags & SEEN))
rev_list_push(parents->item, mark);
if (mark & COMMON)
mark_common(parents->item, 1, 0);
parents = parents->next;
}
rev_list = rev_list->next;
}
return commit->object.sha1;
}
static int find_common(int fd[2], unsigned char *result_sha1,
struct ref *refs)
{
int fetching;
int count = 0, flushes = 0, retval;
const unsigned char *sha1;
for_each_ref(rev_list_insert_ref);
fetching = 0;
for ( ; refs ; refs = refs->next) {
unsigned char *remote = refs->old_sha1;
struct object *o;
/*
* If that object is complete (i.e. it is an ancestor of a
* local ref), we tell them we have it but do not have to
* tell them about its ancestors, which they already know
* about.
*
* We use lookup_object here because we are only
* interested in the case we *know* the object is
* reachable and we have already scanned it.
*/
if (((o = lookup_object(remote)) != NULL) &&
(o->flags & COMPLETE)) {
continue;
}
packet_write(fd[1], "want %s%s%s\n", sha1_to_hex(remote),
(multi_ack ? " multi_ack" : ""),
(use_thin_pack ? " thin-pack" : ""));
fetching++;
}
packet_flush(fd[1]);
if (!fetching)
return 1;
flushes = 0;
retval = -1;
while ((sha1 = get_rev())) {
packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
if (verbose)
fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
if (!(31 & ++count)) {
int ack;
packet_flush(fd[1]);
flushes++;
/*
* We keep one window "ahead" of the other side, and
* will wait for an ACK only on the next one
*/
if (count == 32)
continue;
do {
ack = get_ack(fd[0], result_sha1);
if (verbose && ack)
fprintf(stderr, "got ack %d %s\n", ack,
sha1_to_hex(result_sha1));
if (ack == 1) {
flushes = 0;
multi_ack = 0;
retval = 0;
goto done;
} else if (ack == 2) {
struct commit *commit =
lookup_commit(result_sha1);
mark_common(commit, 0, 1);
retval = 0;
}
} while (ack);
flushes--;
}
}
done:
packet_write(fd[1], "done\n");
if (verbose)
fprintf(stderr, "done\n");
if (retval != 0) {
multi_ack = 0;
flushes++;
}
while (flushes || multi_ack) {
int ack = get_ack(fd[0], result_sha1);
if (ack) {
if (verbose)
fprintf(stderr, "got ack (%d) %s\n", ack,
sha1_to_hex(result_sha1));
if (ack == 1)
return 0;
multi_ack = 1;
continue;
}
flushes--;
}
return retval;
}
static struct commit_list *complete = NULL;
static int mark_complete(const char *path, const unsigned char *sha1)
{
struct object *o = parse_object(sha1);
while (o && o->type == tag_type) {
struct tag *t = (struct tag *) o;
if (!t->tagged)
break; /* broken repository */
o->flags |= COMPLETE;
o = parse_object(t->tagged->sha1);
}
if (o && o->type == commit_type) {
struct commit *commit = (struct commit *)o;
commit->object.flags |= COMPLETE;
insert_by_date(commit, &complete);
}
return 0;
}
static void mark_recent_complete_commits(unsigned long cutoff)
{
while (complete && cutoff <= complete->item->date) {
if (verbose)
fprintf(stderr, "Marking %s as complete\n",
sha1_to_hex(complete->item->object.sha1));
pop_most_recent_commit(&complete, COMPLETE);
}
}
static void filter_refs(struct ref **refs, int nr_match, char **match)
{
struct ref *prev, *current, *next;
for (prev = NULL, current = *refs; current; current = next) {
next = current->next;
if ((!memcmp(current->name, "refs/", 5) &&
check_ref_format(current->name + 5)) ||
(!fetch_all &&
!path_match(current->name, nr_match, match))) {
if (prev == NULL)
*refs = next;
else
prev->next = next;
free(current);
} else
prev = current;
}
}
static int everything_local(struct ref **refs, int nr_match, char **match)
{
struct ref *ref;
int retval;
unsigned long cutoff = 0;
track_object_refs = 0;
save_commit_buffer = 0;
for (ref = *refs; ref; ref = ref->next) {
struct object *o;
o = parse_object(ref->old_sha1);
if (!o)
continue;
/* We already have it -- which may mean that we were
* in sync with the other side at some time after
* that (it is OK if we guess wrong here).
*/
if (o->type == commit_type) {
struct commit *commit = (struct commit *)o;
if (!cutoff || cutoff < commit->date)
cutoff = commit->date;
}
}
for_each_ref(mark_complete);
if (cutoff)
mark_recent_complete_commits(cutoff);
/*
* Mark all complete remote refs as common refs.
* Don't mark them common yet; the server has to be told so first.
*/
for (ref = *refs; ref; ref = ref->next) {
struct object *o = deref_tag(lookup_object(ref->old_sha1),
NULL, 0);
if (!o || o->type != commit_type || !(o->flags & COMPLETE))
continue;
if (!(o->flags & SEEN)) {
rev_list_push((struct commit *)o, COMMON_REF | SEEN);
mark_common((struct commit *)o, 1, 1);
}
}
filter_refs(refs, nr_match, match);
for (retval = 1, ref = *refs; ref ; ref = ref->next) {
const unsigned char *remote = ref->old_sha1;
unsigned char local[20];
struct object *o;
o = lookup_object(remote);
if (!o || !(o->flags & COMPLETE)) {
retval = 0;
if (!verbose)
continue;
fprintf(stderr,
"want %s (%s)\n", sha1_to_hex(remote),
ref->name);
continue;
}
memcpy(ref->new_sha1, local, 20);
if (!verbose)
continue;
fprintf(stderr,
"already have %s (%s)\n", sha1_to_hex(remote),
ref->name);
}
return retval;
}
static int fetch_pack(int fd[2], int nr_match, char **match)
{
struct ref *ref;
unsigned char sha1[20];
int status;
get_remote_heads(fd[0], &ref, 0, NULL, 0);
if (server_supports("multi_ack")) {
if (verbose)
fprintf(stderr, "Server supports multi_ack\n");
multi_ack = 1;
}
if (!ref) {
packet_flush(fd[1]);
die("no matching remote head");
}
if (everything_local(&ref, nr_match, match)) {
packet_flush(fd[1]);
goto all_done;
}
if (find_common(fd, sha1, ref) < 0)
if (!keep_pack)
/* When cloning, it is not unusual to have
* no common commit.
*/
fprintf(stderr, "warning: no common commits\n");
if (keep_pack)
status = receive_keep_pack(fd, "git-fetch-pack", quiet);
else
status = receive_unpack_pack(fd, "git-fetch-pack", quiet);
if (status)
die("git-fetch-pack: fetch failed.");
all_done:
while (ref) {
printf("%s %s\n",
sha1_to_hex(ref->old_sha1), ref->name);
ref = ref->next;
}
return 0;
}
int main(int argc, char **argv)
{
int i, ret, nr_heads;
char *dest = NULL, **heads;
int fd[2];
pid_t pid;
setup_git_directory();
nr_heads = 0;
heads = NULL;
for (i = 1; i < argc; i++) {
char *arg = argv[i];
if (*arg == '-') {
if (!strncmp("--exec=", arg, 7)) {
exec = arg + 7;
continue;
}
if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
quiet = 1;
continue;
}
if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
keep_pack = 1;
continue;
}
if (!strcmp("--thin", arg)) {
use_thin_pack = 1;
continue;
}
if (!strcmp("--all", arg)) {
fetch_all = 1;
continue;
}
if (!strcmp("-v", arg)) {
verbose = 1;
continue;
}
usage(fetch_pack_usage);
}
dest = arg;
heads = argv + i + 1;
nr_heads = argc - i - 1;
break;
}
if (!dest)
usage(fetch_pack_usage);
if (keep_pack)
use_thin_pack = 0;
pid = git_connect(fd, dest, exec);
if (pid < 0)
return 1;
ret = fetch_pack(fd, nr_heads, heads);
close(fd[0]);
close(fd[1]);
finish_connect(pid);
if (!ret && nr_heads) {
/* If the heads to pull were given, we should have
* consumed all of them by matching the remote.
* Otherwise, 'git-fetch remote no-such-ref' would
* silently succeed without issuing an error.
*/
for (i = 0; i < nr_heads; i++)
if (heads[i] && heads[i][0]) {
error("no such remote ref %s", heads[i]);
ret = 1;
}
}
return ret;
}