Revision 2408cff9f738459019709c8c12d0bd8a5605566f authored by Linus Torvalds on 14 July 2005, 00:27:48 UTC, committed by Linus Torvalds on 14 July 2005, 00:27:48 UTC
We should always have unlinked any old ones before, but this just makes sure that we never over-write any old file. A quick "grep" now shows that all the core tools that open files for writing use O_EXCL, ie we never overwrite an existing file in place.
1 parent 1b66834
clone-pack.c
#include "cache.h"
#include "refs.h"
#include "pkt-line.h"
#include <sys/wait.h>
static int quiet;
static const char clone_pack_usage[] = "git-clone-pack [host:]directory [heads]*";
static const char *exec = "git-upload-pack";
struct ref {
struct ref *next;
unsigned char sha1[20];
char name[0];
};
static struct ref *get_remote_refs(int fd, int nr_match, char **match)
{
struct ref *ref_list = NULL, **next_ref = &ref_list;
for (;;) {
static char line[1000];
unsigned char sha1[20];
struct ref *ref;
char *refname;
int len;
len = packet_read_line(fd, line, sizeof(line));
if (!len)
break;
if (line[len-1] == '\n')
line[--len] = 0;
if (len < 42 || get_sha1_hex(line, sha1))
die("git-fetch-pack: protocol error - expected ref descriptor, got '%s¤'", line);
refname = line+41;
len = len-40;
if (nr_match && !path_match(refname, nr_match, match))
continue;
ref = xmalloc(sizeof(struct ref) + len);
ref->next = NULL;
memcpy(ref->sha1, sha1, 20);
memcpy(ref->name, refname, len);
*next_ref = ref;
next_ref = &ref->next;
}
return ref_list;
}
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->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(ref->name);
int fd;
char *hex;
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->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;
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->sha1, head->sha1, 20)) {
if (!head_ptr || ref == master_ref)
head_ptr = ref;
}
write_one_ref(ref);
ref = ref->next;
}
if (!head)
return;
head_path = 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);
return;
}
/* We reset to the master branch if it's available */
if (master_ref)
return;
/*
* Uhhuh. Other end didn't have master. We start HEAD off with
* the first branch with the same value.
*/
unlink(head_path);
if (symlink(head_ptr->name, head_path) < 0)
die("unable to link HEAD to %s", head_ptr->name);
}
static int clone_pack(int fd[2], int nr_match, char **match)
{
struct ref *refs;
int status;
pid_t pid;
refs = get_remote_refs(fd[0], nr_match, match);
if (!refs) {
packet_flush(fd[1]);
die("no matching remote head");
}
clone_handshake(fd, refs);
pid = fork();
if (pid < 0)
die("git-clone-pack: unable to fork off git-unpack-objects");
if (!pid) {
close(fd[1]);
dup2(fd[0], 0);
close(fd[0]);
execlp("git-unpack-objects", "git-unpack-objects",
quiet ? "-q" : NULL, NULL);
die("git-unpack-objects exec failed");
}
close(fd[0]);
close(fd[1]);
while (waitpid(pid, &status, 0) < 0) {
if (errno != EINTR)
die("waiting for git-unpack-objects: %s", strerror(errno));
}
if (WIFEXITED(status)) {
int code = WEXITSTATUS(status);
if (code)
die("git-unpack-objects died with error code %d", code);
write_refs(refs);
return 0;
}
if (WIFSIGNALED(status)) {
int sig = WTERMSIG(status);
die("git-unpack-objects died of signal %d", sig);
}
die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
}
int main(int argc, char **argv)
{
int i, ret, nr_heads;
char *dest = NULL, **heads;
int fd[2];
pid_t pid;
nr_heads = 0;
heads = NULL;
for (i = 1; i < argc; i++) {
char *arg = argv[i];
if (*arg == '-') {
if (!strcmp("-q", arg)) {
quiet = 1;
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;
}
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...