git/builtin-send-pack.c
Andy Whitcroft 28b9d6e548 Teach send-pack a mirror mode
Existing "git push --all" is almost perfect for backing up to
another repository, except that "--all" only means "all
branches" in modern git, and it does not delete old branches and
tags that exist at the back-up repository that you have removed
from your local repository.

This teaches "git-send-pack" a new "--mirror" option.  The
difference from the "--all" option are that (1) it sends all
refs, not just branches, and (2) it deletes old refs you no
longer have on the local side from the remote side.

Original patch by Junio C Hamano.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-11-09 21:14:10 -08:00

540 lines
13 KiB
C

#include "cache.h"
#include "commit.h"
#include "tag.h"
#include "refs.h"
#include "pkt-line.h"
#include "run-command.h"
#include "remote.h"
#include "send-pack.h"
static const char send_pack_usage[] =
"git-send-pack [--all | --mirror] [--dry-run] [--force] [--receive-pack=<git-receive-pack>] [--verbose] [--thin] [<host>:]<directory> [<ref>...]\n"
" --all and explicit <ref> specification are mutually exclusive.";
static struct send_pack_args args = {
/* .receivepack = */ "git-receive-pack",
};
/*
* Make a pack stream and spit it out into file descriptor fd
*/
static int pack_objects(int fd, struct ref *refs)
{
/*
* The child becomes pack-objects --revs; we feed
* the revision parameters to it via its stdin and
* let its stdout go back to the other end.
*/
const char *argv[] = {
"pack-objects",
"--all-progress",
"--revs",
"--stdout",
NULL,
NULL,
};
struct child_process po;
if (args.use_thin_pack)
argv[4] = "--thin";
memset(&po, 0, sizeof(po));
po.argv = argv;
po.in = -1;
po.out = fd;
po.git_cmd = 1;
if (start_command(&po))
die("git-pack-objects failed (%s)", strerror(errno));
/*
* We feed the pack-objects we just spawned with revision
* parameters by writing to the pipe.
*/
while (refs) {
char buf[42];
if (!is_null_sha1(refs->old_sha1) &&
has_sha1_file(refs->old_sha1)) {
memcpy(buf + 1, sha1_to_hex(refs->old_sha1), 40);
buf[0] = '^';
buf[41] = '\n';
if (!write_or_whine(po.in, buf, 42,
"send-pack: send refs"))
break;
}
if (!is_null_sha1(refs->new_sha1)) {
memcpy(buf, sha1_to_hex(refs->new_sha1), 40);
buf[40] = '\n';
if (!write_or_whine(po.in, buf, 41,
"send-pack: send refs"))
break;
}
refs = refs->next;
}
if (finish_command(&po))
return error("pack-objects died with strange error");
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 != OBJ_COMMIT)
return 0;
old = (struct commit *) o;
o = deref_tag(parse_object(new_sha1), NULL, 0);
if (!o || o->type != OBJ_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, int flag, void *cb_data)
{
struct ref *ref;
int len = strlen(refname) + 1;
ref = xcalloc(1, sizeof(*ref) + len);
hashcpy(ref->new_sha1, sha1);
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, NULL);
}
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 void update_tracking_ref(struct remote *remote, struct ref *ref)
{
struct refspec rs;
int will_delete_ref;
rs.src = ref->name;
rs.dst = NULL;
if (!ref->peer_ref)
return;
will_delete_ref = is_null_sha1(ref->peer_ref->new_sha1);
if (!will_delete_ref &&
!hashcmp(ref->old_sha1, ref->peer_ref->new_sha1))
return;
if (!remote_find_tracking(remote, &rs)) {
if (args.verbose)
fprintf(stderr, "updating local tracking ref '%s'\n", rs.dst);
if (is_null_sha1(ref->peer_ref->new_sha1)) {
if (delete_ref(rs.dst, NULL))
error("Failed to delete");
} else
update_ref("update by push", rs.dst,
ref->new_sha1, NULL, 0, 0);
free(rs.dst);
}
}
static const char *prettify_ref(const char *name)
{
return name + (
!prefixcmp(name, "refs/heads/") ? 11 :
!prefixcmp(name, "refs/tags/") ? 10 :
!prefixcmp(name, "refs/remotes/") ? 13 :
0);
}
#define SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3)
static int do_send_pack(int in, int out, struct remote *remote, const char *dest, int nr_refspec, const char **refspec)
{
struct ref *ref;
int new_refs;
int ret = 0;
int ask_for_status_report = 0;
int allow_deleting_refs = 0;
int expect_status_report = 0;
int shown_dest = 0;
int flags = MATCH_REFS_NONE;
if (args.send_all)
flags |= MATCH_REFS_ALL;
if (args.send_mirror)
flags |= MATCH_REFS_MIRROR;
/* No funny business with the matcher */
remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, REF_NORMAL);
get_local_heads();
/* Does the other end support the reporting? */
if (server_supports("report-status"))
ask_for_status_report = 1;
if (server_supports("delete-refs"))
allow_deleting_refs = 1;
/* match them up */
if (!remote_tail)
remote_tail = &remote_refs;
if (match_refs(local_refs, remote_refs, &remote_tail,
nr_refspec, refspec, flags))
return -1;
if (!remote_refs) {
fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
"Perhaps you should specify a branch such as 'master'.\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;
int will_delete_ref;
const char *pretty_ref;
const char *pretty_peer = NULL; /* only used when not deleting */
const unsigned char *new_sha1;
if (!ref->peer_ref) {
if (!args.send_mirror)
continue;
new_sha1 = null_sha1;
}
else
new_sha1 = ref->peer_ref->new_sha1;
if (!shown_dest) {
fprintf(stderr, "To %s\n", dest);
shown_dest = 1;
}
will_delete_ref = is_null_sha1(new_sha1);
pretty_ref = prettify_ref(ref->name);
if (!will_delete_ref)
pretty_peer = prettify_ref(ref->peer_ref->name);
if (will_delete_ref && !allow_deleting_refs) {
fprintf(stderr, " ! %-*s %s (remote does not support deleting refs)\n",
SUMMARY_WIDTH, "[rejected]", pretty_ref);
ret = -2;
continue;
}
if (!will_delete_ref &&
!hashcmp(ref->old_sha1, new_sha1)) {
if (args.verbose)
fprintf(stderr, " = %-*s %s -> %s\n",
SUMMARY_WIDTH, "[up to date]",
pretty_peer, pretty_ref);
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.
*
* (4) regardless of all of the above, removing :B is
* always allowed.
*/
if (!args.force_update &&
!will_delete_ref &&
!is_null_sha1(ref->old_sha1) &&
!ref->force) {
if (!has_sha1_file(ref->old_sha1) ||
!ref_newer(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.
*/
fprintf(stderr, " ! %-*s %s -> %s (non-fast forward)\n",
SUMMARY_WIDTH, "[rejected]",
pretty_peer, pretty_ref);
ret = -2;
continue;
}
}
hashcpy(ref->new_sha1, new_sha1);
if (!will_delete_ref)
new_refs++;
strcpy(old_hex, sha1_to_hex(ref->old_sha1));
new_hex = sha1_to_hex(ref->new_sha1);
if (!args.dry_run) {
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);
}
if (will_delete_ref)
fprintf(stderr, " - %-*s %s\n",
SUMMARY_WIDTH, "[deleting]",
pretty_ref);
else if (is_null_sha1(ref->old_sha1)) {
const char *msg;
if (!prefixcmp(ref->name, "refs/tags/"))
msg = "[new tag]";
else
msg = "[new branch]";
fprintf(stderr, " * %-*s %s -> %s\n",
SUMMARY_WIDTH, msg,
pretty_peer, pretty_ref);
}
else {
char quickref[83];
char type = ' ';
const char *msg = "";
const char *old_abb;
old_abb = find_unique_abbrev(ref->old_sha1, DEFAULT_ABBREV);
strcpy(quickref, old_abb ? old_abb : old_hex);
if (ref_newer(ref->peer_ref->new_sha1, ref->old_sha1))
strcat(quickref, "..");
else {
strcat(quickref, "...");
type = '+';
msg = " (forced update)";
}
strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
fprintf(stderr, " %c %-*s %s -> %s%s\n",
type,
SUMMARY_WIDTH, quickref,
pretty_peer, pretty_ref,
msg);
}
}
packet_flush(out);
if (new_refs && !args.dry_run)
ret = pack_objects(out, remote_refs);
close(out);
if (expect_status_report) {
if (receive_status(in))
ret = -4;
}
if (!args.dry_run && remote && ret == 0) {
for (ref = remote_refs; ref; ref = ref->next)
update_tracking_ref(remote, ref);
}
if (!new_refs && ret == 0)
fprintf(stderr, "Everything up-to-date\n");
return ret;
}
static void verify_remote_names(int nr_heads, const char **heads)
{
int i;
for (i = 0; i < nr_heads; i++) {
const char *remote = strchr(heads[i], ':');
remote = remote ? (remote + 1) : heads[i];
switch (check_ref_format(remote)) {
case 0: /* ok */
case -2: /* ok but a single level -- that is fine for
* a match pattern.
*/
case -3: /* ok but ends with a pattern-match character */
continue;
}
die("remote part of refspec is not a valid name in %s",
heads[i]);
}
}
int cmd_send_pack(int argc, const char **argv, const char *prefix)
{
int i, nr_heads = 0;
const char **heads = NULL;
const char *remote_name = NULL;
struct remote *remote = NULL;
const char *dest = NULL;
argv++;
for (i = 1; i < argc; i++, argv++) {
const char *arg = *argv;
if (*arg == '-') {
if (!prefixcmp(arg, "--receive-pack=")) {
args.receivepack = arg + 15;
continue;
}
if (!prefixcmp(arg, "--exec=")) {
args.receivepack = arg + 7;
continue;
}
if (!prefixcmp(arg, "--remote=")) {
remote_name = arg + 9;
continue;
}
if (!strcmp(arg, "--all")) {
args.send_all = 1;
continue;
}
if (!strcmp(arg, "--dry-run")) {
args.dry_run = 1;
continue;
}
if (!strcmp(arg, "--mirror")) {
args.send_mirror = 1;
continue;
}
if (!strcmp(arg, "--force")) {
args.force_update = 1;
continue;
}
if (!strcmp(arg, "--verbose")) {
args.verbose = 1;
continue;
}
if (!strcmp(arg, "--thin")) {
args.use_thin_pack = 1;
continue;
}
usage(send_pack_usage);
}
if (!dest) {
dest = arg;
continue;
}
heads = (const char **) argv;
nr_heads = argc - i;
break;
}
if (!dest)
usage(send_pack_usage);
/*
* --all and --mirror are incompatible; neither makes sense
* with any refspecs.
*/
if ((heads && (args.send_all || args.send_mirror)) ||
(args.send_all && args.send_mirror))
usage(send_pack_usage);
if (remote_name) {
remote = remote_get(remote_name);
if (!remote_has_url(remote, dest)) {
die("Destination %s is not a uri for %s",
dest, remote_name);
}
}
return send_pack(&args, dest, remote, nr_heads, heads);
}
int send_pack(struct send_pack_args *my_args,
const char *dest, struct remote *remote,
int nr_heads, const char **heads)
{
int fd[2], ret;
struct child_process *conn;
memcpy(&args, my_args, sizeof(args));
verify_remote_names(nr_heads, heads);
conn = git_connect(fd, dest, args.receivepack, args.verbose ? CONNECT_VERBOSE : 0);
ret = do_send_pack(fd[0], fd[1], remote, dest, nr_heads, heads);
close(fd[0]);
close(fd[1]);
ret |= finish_connect(conn);
return !!ret;
}