git-commit-vandalism/builtin-send-pack.c
Junio C Hamano 40c155ff14 push: prepare sender to receive extended ref information from the receiver
"git push" enhancement allows the receiving end to report not only its own
refs but refs in repositories it borrows from via the alternate object
store mechanism.  By telling the sender that objects reachable from these
extra refs are already complete in the receiving end, the number of
objects that need to be transfered can be cut down.

These entries are sent over the wire with string ".have", instead of the
actual names of the refs.  This string was chosen so that they are ignored
by older programs at the sending end.  If we sent some random but valid
looking refnames for these entries, "matching refs" rule (triggered when
running "git push" without explicit refspecs, where the sender learns what
refs the receiver has, and updates only the ones with the names of the
refs the sender also has) and "delete missing" rule (triggered when "git
push --mirror" is used, where the sender tells the receiver to delete the
refs it itself does not have) would try to update/delete them, which is
not what we want.

This prepares the send-pack (and "push" that runs native protocol) to
accept extended existing ref information and make use of it.  The ".have"
entries are excluded from ref matching rules, and are exempt from deletion
rule while pushing with --mirror option, but are still used for pack
generation purposes by providing more "bottom" range commits.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-09 09:27:46 -07:00

674 lines
15 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, struct extra_have_objects *extra)
{
/*
* 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;
int i;
char buf[42];
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.
*/
for (i = 0; i < extra->nr; i++) {
memcpy(buf + 1, sha1_to_hex(&extra->array[i][0]), 40);
buf[0] = '^';
buf[41] = '\n';
if (!write_or_whine(po.in, buf, 42, "send-pack: send refs"))
break;
}
while (refs) {
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;
}
close(po.in);
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, struct ref *refs)
{
struct ref *hint;
char line[1000];
int ret = 0;
int len = packet_read_line(in, line, sizeof(line));
if (len < 10 || memcmp(line, "unpack ", 7))
return error("did not receive remote status");
if (memcmp(line, "unpack ok\n", 10)) {
char *p = line + strlen(line) - 1;
if (*p == '\n')
*p = '\0';
error("unpack failed: %s", line + 7);
ret = -1;
}
hint = NULL;
while (1) {
char *refname;
char *msg;
len = packet_read_line(in, line, sizeof(line));
if (!len)
break;
if (len < 3 ||
(memcmp(line, "ok ", 3) && memcmp(line, "ng ", 3))) {
fprintf(stderr, "protocol error: %s\n", line);
ret = -1;
break;
}
line[strlen(line)-1] = '\0';
refname = line + 3;
msg = strchr(refname, ' ');
if (msg)
*msg++ = '\0';
/* first try searching at our hint, falling back to all refs */
if (hint)
hint = find_ref_by_name(hint, refname);
if (!hint)
hint = find_ref_by_name(refs, refname);
if (!hint) {
warning("remote reported status on unknown ref: %s",
refname);
continue;
}
if (hint->status != REF_STATUS_EXPECTING_REPORT) {
warning("remote reported status on unexpected ref: %s",
refname);
continue;
}
if (line[0] == 'o' && line[1] == 'k')
hint->status = REF_STATUS_OK;
else {
hint->status = REF_STATUS_REMOTE_REJECT;
ret = -1;
}
if (msg)
hint->remote_status = xstrdup(msg);
/* start our next search from the next ref */
hint = hint->next;
}
return ret;
}
static void update_tracking_ref(struct remote *remote, struct ref *ref)
{
struct refspec rs;
if (ref->status != REF_STATUS_OK)
return;
rs.src = ref->name;
rs.dst = NULL;
if (!remote_find_tracking(remote, &rs)) {
if (args.verbose)
fprintf(stderr, "updating local tracking ref '%s'\n", rs.dst);
if (ref->deletion) {
delete_ref(rs.dst, NULL);
} else
update_ref("update by push", rs.dst,
ref->new_sha1, NULL, 0, 0);
free(rs.dst);
}
}
static const char *prettify_ref(const struct ref *ref)
{
const char *name = ref->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 void print_ref_status(char flag, const char *summary, struct ref *to, struct ref *from, const char *msg)
{
fprintf(stderr, " %c %-*s ", flag, SUMMARY_WIDTH, summary);
if (from)
fprintf(stderr, "%s -> %s", prettify_ref(from), prettify_ref(to));
else
fputs(prettify_ref(to), stderr);
if (msg) {
fputs(" (", stderr);
fputs(msg, stderr);
fputc(')', stderr);
}
fputc('\n', stderr);
}
static const char *status_abbrev(unsigned char sha1[20])
{
return find_unique_abbrev(sha1, DEFAULT_ABBREV);
}
static void print_ok_ref_status(struct ref *ref)
{
if (ref->deletion)
print_ref_status('-', "[deleted]", ref, NULL, NULL);
else if (is_null_sha1(ref->old_sha1))
print_ref_status('*',
(!prefixcmp(ref->name, "refs/tags/") ? "[new tag]" :
"[new branch]"),
ref, ref->peer_ref, NULL);
else {
char quickref[84];
char type;
const char *msg;
strcpy(quickref, status_abbrev(ref->old_sha1));
if (ref->nonfastforward) {
strcat(quickref, "...");
type = '+';
msg = "forced update";
} else {
strcat(quickref, "..");
type = ' ';
msg = NULL;
}
strcat(quickref, status_abbrev(ref->new_sha1));
print_ref_status(type, quickref, ref, ref->peer_ref, msg);
}
}
static int print_one_push_status(struct ref *ref, const char *dest, int count)
{
if (!count)
fprintf(stderr, "To %s\n", dest);
switch(ref->status) {
case REF_STATUS_NONE:
print_ref_status('X', "[no match]", ref, NULL, NULL);
break;
case REF_STATUS_REJECT_NODELETE:
print_ref_status('!', "[rejected]", ref, NULL,
"remote does not support deleting refs");
break;
case REF_STATUS_UPTODATE:
print_ref_status('=', "[up to date]", ref,
ref->peer_ref, NULL);
break;
case REF_STATUS_REJECT_NONFASTFORWARD:
print_ref_status('!', "[rejected]", ref, ref->peer_ref,
"non-fast forward");
break;
case REF_STATUS_REMOTE_REJECT:
print_ref_status('!', "[remote rejected]", ref,
ref->deletion ? NULL : ref->peer_ref,
ref->remote_status);
break;
case REF_STATUS_EXPECTING_REPORT:
print_ref_status('!', "[remote failure]", ref,
ref->deletion ? NULL : ref->peer_ref,
"remote failed to report status");
break;
case REF_STATUS_OK:
print_ok_ref_status(ref);
break;
}
return 1;
}
static void print_push_status(const char *dest, struct ref *refs)
{
struct ref *ref;
int n = 0;
if (args.verbose) {
for (ref = refs; ref; ref = ref->next)
if (ref->status == REF_STATUS_UPTODATE)
n += print_one_push_status(ref, dest, n);
}
for (ref = refs; ref; ref = ref->next)
if (ref->status == REF_STATUS_OK)
n += print_one_push_status(ref, dest, n);
for (ref = refs; ref; ref = ref->next) {
if (ref->status != REF_STATUS_NONE &&
ref->status != REF_STATUS_UPTODATE &&
ref->status != REF_STATUS_OK)
n += print_one_push_status(ref, dest, n);
}
}
static int refs_pushed(struct ref *ref)
{
for (; ref; ref = ref->next) {
switch(ref->status) {
case REF_STATUS_NONE:
case REF_STATUS_UPTODATE:
break;
default:
return 1;
}
}
return 0;
}
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 ask_for_status_report = 0;
int allow_deleting_refs = 0;
int expect_status_report = 0;
int flags = MATCH_REFS_NONE;
int ret;
struct extra_have_objects extra_have;
memset(&extra_have, 0, sizeof(extra_have));
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,
&extra_have);
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)) {
close(out);
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");
close(out);
return 0;
}
/*
* Finally, tell the other end!
*/
new_refs = 0;
for (ref = remote_refs; ref; ref = ref->next) {
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;
ref->deletion = is_null_sha1(new_sha1);
if (ref->deletion && !allow_deleting_refs) {
ref->status = REF_STATUS_REJECT_NODELETE;
continue;
}
if (!ref->deletion &&
!hashcmp(ref->old_sha1, new_sha1)) {
ref->status = REF_STATUS_UPTODATE;
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.
*/
ref->nonfastforward =
!ref->deletion &&
!is_null_sha1(ref->old_sha1) &&
(!has_sha1_file(ref->old_sha1)
|| !ref_newer(new_sha1, ref->old_sha1));
if (ref->nonfastforward && !ref->force && !args.force_update) {
ref->status = REF_STATUS_REJECT_NONFASTFORWARD;
continue;
}
hashcpy(ref->new_sha1, new_sha1);
if (!ref->deletion)
new_refs++;
if (!args.dry_run) {
char *old_hex = sha1_to_hex(ref->old_sha1);
char *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);
}
ref->status = expect_status_report ?
REF_STATUS_EXPECTING_REPORT :
REF_STATUS_OK;
}
packet_flush(out);
if (new_refs && !args.dry_run) {
if (pack_objects(out, remote_refs, &extra_have) < 0)
return -1;
}
else
close(out);
if (expect_status_report)
ret = receive_status(in, remote_refs);
else
ret = 0;
print_push_status(dest, remote_refs);
if (!args.dry_run && remote) {
for (ref = remote_refs; ref; ref = ref->next)
update_tracking_ref(remote, ref);
}
if (!refs_pushed(remote_refs))
fprintf(stderr, "Everything up-to-date\n");
if (ret < 0)
return ret;
for (ref = remote_refs; ref; ref = ref->next) {
switch (ref->status) {
case REF_STATUS_NONE:
case REF_STATUS_UPTODATE:
case REF_STATUS_OK:
break;
default:
return -1;
}
}
return 0;
}
static void verify_remote_names(int nr_heads, const char **heads)
{
int i;
for (i = 0; i < nr_heads; i++) {
const char *local = heads[i];
const char *remote = strrchr(heads[i], ':');
if (*local == '+')
local++;
/* A matching refspec is okay. */
if (remote == local && remote[1] == '\0')
continue;
remote = remote ? (remote + 1) : local;
switch (check_ref_format(remote)) {
case 0: /* ok */
case CHECK_REF_FORMAT_ONELEVEL:
/* ok but a single level -- that is fine for
* a match pattern.
*/
case CHECK_REF_FORMAT_WILDCARD:
/* 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]);
/* do_send_pack always closes fd[1] */
ret |= finish_connect(conn);
return !!ret;
}