git/clone-pack.c

308 строки
6.6 KiB
C

#include "cache.h"
#include "refs.h"
#include "pkt-line.h"
#include <sys/wait.h>
static const char clone_pack_usage[] =
"git-clone-pack [--exec=<git-upload-pack>] [<host>:]<directory> [<heads>]*";
static const char *exec = "git-upload-pack";
static void clone_handshake(int fd[2], struct ref *ref)
{
unsigned char sha1[20];
while (ref) {
packet_write(fd[1], "want %s\n", sha1_to_hex(ref->old_sha1));
ref = ref->next;
}
packet_flush(fd[1]);
/* We don't have nuttin' */
packet_write(fd[1], "done\n");
if (get_ack(fd[0], sha1))
error("Huh! git-clone-pack got positive ack for %s", sha1_to_hex(sha1));
}
static int is_master(struct ref *ref)
{
return !strcmp(ref->name, "refs/heads/master");
}
static void write_one_ref(struct ref *ref)
{
char *path = git_path("%s", ref->name);
int fd;
char *hex;
if (!strncmp(ref->name, "refs/", 5) &&
check_ref_format(ref->name + 5)) {
error("refusing to create funny ref '%s' locally", ref->name);
return;
}
if (safe_create_leading_directories(path))
die("unable to create leading directory for %s", ref->name);
fd = open(path, O_CREAT | O_EXCL | O_WRONLY, 0666);
if (fd < 0)
die("unable to create ref %s", ref->name);
hex = sha1_to_hex(ref->old_sha1);
hex[40] = '\n';
if (write(fd, hex, 41) != 41)
die("unable to write ref %s", ref->name);
close(fd);
}
static void write_refs(struct ref *ref)
{
struct ref *head = NULL, *head_ptr, *master_ref;
char *head_path;
/* Upload-pack must report HEAD first */
if (!strcmp(ref->name, "HEAD")) {
head = ref;
ref = ref->next;
}
head_ptr = NULL;
master_ref = NULL;
while (ref) {
if (is_master(ref))
master_ref = ref;
if (head &&
!memcmp(ref->old_sha1, head->old_sha1, 20) &&
!strncmp(ref->name, "refs/heads/",11) &&
(!head_ptr || ref == master_ref))
head_ptr = ref;
write_one_ref(ref);
ref = ref->next;
}
if (!head) {
fprintf(stderr, "No HEAD in remote.\n");
return;
}
head_path = strdup(git_path("HEAD"));
if (!head_ptr) {
/*
* If we had a master ref, and it wasn't HEAD, we need to undo the
* symlink, and write a standalone HEAD. Give a warning, because that's
* really really wrong.
*/
if (master_ref) {
error("HEAD doesn't point to any refs! Making standalone HEAD");
unlink(head_path);
}
write_one_ref(head);
free(head_path);
return;
}
/* We reset to the master branch if it's available */
if (master_ref)
return;
fprintf(stderr, "Setting HEAD to %s\n", head_ptr->name);
/*
* Uhhuh. Other end didn't have master. We start HEAD off with
* the first branch with the same value.
*/
if (create_symref(head_path, head_ptr->name) < 0)
die("unable to link HEAD to %s", head_ptr->name);
free(head_path);
}
static int finish_pack(const char *pack_tmp_name)
{
int pipe_fd[2];
pid_t pid;
char idx[PATH_MAX];
char final[PATH_MAX];
char hash[41];
unsigned char sha1[20];
char *cp;
int err = 0;
if (pipe(pipe_fd) < 0)
die("git-clone-pack: unable to set up pipe");
strcpy(idx, pack_tmp_name); /* ".git/objects/pack-XXXXXX" */
cp = strrchr(idx, '/');
memcpy(cp, "/pidx", 5);
pid = fork();
if (pid < 0)
die("git-clone-pack: unable to fork off git-index-pack");
if (!pid) {
close(0);
dup2(pipe_fd[1], 1);
close(pipe_fd[0]);
close(pipe_fd[1]);
execlp("git-index-pack","git-index-pack",
"-o", idx, pack_tmp_name, NULL);
error("cannot exec git-index-pack <%s> <%s>",
idx, pack_tmp_name);
exit(1);
}
close(pipe_fd[1]);
if (read(pipe_fd[0], hash, 40) != 40) {
error("git-clone-pack: unable to read from git-index-pack");
err = 1;
}
close(pipe_fd[0]);
for (;;) {
int status, code;
int retval = waitpid(pid, &status, 0);
if (retval < 0) {
if (errno == EINTR)
continue;
error("waitpid failed (%s)", strerror(retval));
goto error_die;
}
if (WIFSIGNALED(status)) {
int sig = WTERMSIG(status);
error("git-index-pack died of signal %d", sig);
goto error_die;
}
if (!WIFEXITED(status)) {
error("git-index-pack died of unnatural causes %d",
status);
goto error_die;
}
code = WEXITSTATUS(status);
if (code) {
error("git-index-pack died with error code %d", code);
goto error_die;
}
if (err)
goto error_die;
break;
}
hash[40] = 0;
if (get_sha1_hex(hash, sha1)) {
error("git-index-pack reported nonsense '%s'", hash);
goto error_die;
}
/* Now we have pack in pack_tmp_name[], and
* idx in idx[]; rename them to their final names.
*/
snprintf(final, sizeof(final),
"%s/pack/pack-%s.pack", get_object_directory(), hash);
move_temp_to_file(pack_tmp_name, final);
chmod(final, 0444);
snprintf(final, sizeof(final),
"%s/pack/pack-%s.idx", get_object_directory(), hash);
move_temp_to_file(idx, final);
chmod(final, 0444);
return 0;
error_die:
unlink(idx);
unlink(pack_tmp_name);
exit(1);
}
static int clone_without_unpack(int fd[2])
{
char tmpfile[PATH_MAX];
int ofd, ifd;
ifd = fd[0];
snprintf(tmpfile, sizeof(tmpfile),
"%s/pack/tmp-XXXXXX", get_object_directory());
ofd = mkstemp(tmpfile);
if (ofd < 0)
return error("unable to create temporary file %s", tmpfile);
while (1) {
char buf[8192];
ssize_t sz, wsz, pos;
sz = read(ifd, buf, sizeof(buf));
if (sz == 0)
break;
if (sz < 0) {
error("error reading pack (%s)", strerror(errno));
close(ofd);
unlink(tmpfile);
return -1;
}
pos = 0;
while (pos < sz) {
wsz = write(ofd, buf + pos, sz - pos);
if (wsz < 0) {
error("error writing pack (%s)",
strerror(errno));
close(ofd);
unlink(tmpfile);
return -1;
}
pos += wsz;
}
}
close(ofd);
return finish_pack(tmpfile);
}
static int clone_pack(int fd[2], int nr_match, char **match)
{
struct ref *refs;
int status;
get_remote_heads(fd[0], &refs, nr_match, match, 1);
if (!refs) {
packet_flush(fd[1]);
die("no matching remote head");
}
clone_handshake(fd, refs);
status = clone_without_unpack(fd);
if (!status)
write_refs(refs);
return status;
}
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 (!strcmp("-q", arg))
continue;
if (!strncmp("--exec=", arg, 7)) {
exec = arg + 7;
continue;
}
if (!strcmp("--keep", arg))
continue;
usage(clone_pack_usage);
}
dest = arg;
heads = argv + i + 1;
nr_heads = argc - i - 1;
break;
}
if (!dest)
usage(clone_pack_usage);
pid = git_connect(fd, dest, exec);
if (pid < 0)
return 1;
ret = clone_pack(fd, nr_heads, heads);
close(fd[0]);
close(fd[1]);
finish_connect(pid);
return ret;
}