upload-pack.c
#include "cache.h"
#include "refs.h"
#include "pkt-line.h"
#include "tag.h"
#include "object.h"
#include "commit.h"
static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
#define THEY_HAVE (1U << 0)
#define OUR_REF (1U << 1)
#define WANTED (1U << 2)
#define MAX_HAS 256
#define MAX_NEEDS 256
static int nr_has = 0, nr_needs = 0, multi_ack = 0, nr_our_refs = 0;
static unsigned char has_sha1[MAX_HAS][20];
static unsigned char needs_sha1[MAX_NEEDS][20];
static unsigned int timeout = 0;
static void reset_timeout(void)
{
alarm(timeout);
}
static int strip(char *line, int len)
{
if (len && line[len-1] == '\n')
line[--len] = 0;
return len;
}
static void create_pack_file(void)
{
int fd[2];
pid_t pid;
int create_full_pack = (nr_our_refs == nr_needs && !nr_has);
if (pipe(fd) < 0)
die("git-upload-pack: unable to create pipe");
pid = fork();
if (pid < 0)
die("git-upload-pack: unable to fork git-rev-list");
if (!pid) {
int i;
int args;
char **argv;
char *buf;
char **p;
if (create_full_pack)
args = 10;
else
args = nr_has + nr_needs + 5;
argv = xmalloc(args * sizeof(char *));
buf = xmalloc(args * 45);
p = argv;
dup2(fd[1], 1);
close(0);
close(fd[0]);
close(fd[1]);
*p++ = "git-rev-list";
*p++ = "--objects";
if (create_full_pack || MAX_NEEDS <= nr_needs)
*p++ = "--all";
else {
for (i = 0; i < nr_needs; i++) {
*p++ = buf;
memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
buf += 41;
}
}
if (!create_full_pack)
for (i = 0; i < nr_has; i++) {
*p++ = buf;
*buf++ = '^';
memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
buf += 41;
}
*p++ = NULL;
execvp("git-rev-list", argv);
die("git-upload-pack: unable to exec git-rev-list");
}
dup2(fd[0], 0);
close(fd[0]);
close(fd[1]);
execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
die("git-upload-pack: unable to exec git-pack-objects");
}
static int got_sha1(char *hex, unsigned char *sha1)
{
if (get_sha1_hex(hex, sha1))
die("git-upload-pack: expected SHA1 object, got '%s'", hex);
if (!has_sha1_file(sha1))
return 0;
if (nr_has < MAX_HAS) {
struct object *o = lookup_object(sha1);
if (!(o && o->parsed))
o = parse_object(sha1);
if (!o)
die("oops (%s)", sha1_to_hex(sha1));
if (o->type == commit_type) {
struct commit_list *parents;
if (o->flags & THEY_HAVE)
return 0;
o->flags |= THEY_HAVE;
for (parents = ((struct commit*)o)->parents;
parents;
parents = parents->next)
parents->item->object.flags |= THEY_HAVE;
}
memcpy(has_sha1[nr_has++], sha1, 20);
}
return 1;
}
static int get_common_commits(void)
{
static char line[1000];
unsigned char sha1[20], last_sha1[20];
int len;
track_object_refs = 0;
save_commit_buffer = 0;
for(;;) {
len = packet_read_line(0, line, sizeof(line));
reset_timeout();
if (!len) {
if (nr_has == 0 || multi_ack)
packet_write(1, "NAK\n");
continue;
}
len = strip(line, len);
if (!strncmp(line, "have ", 5)) {
if (got_sha1(line+5, sha1) &&
(multi_ack || nr_has == 1)) {
if (nr_has >= MAX_HAS)
multi_ack = 0;
packet_write(1, "ACK %s%s\n",
sha1_to_hex(sha1),
multi_ack ? " continue" : "");
if (multi_ack)
memcpy(last_sha1, sha1, 20);
}
continue;
}
if (!strcmp(line, "done")) {
if (nr_has > 0) {
if (multi_ack)
packet_write(1, "ACK %s\n",
sha1_to_hex(last_sha1));
return 0;
}
packet_write(1, "NAK\n");
return -1;
}
die("git-upload-pack: expected SHA1 list, got '%s'", line);
}
}
static int receive_needs(void)
{
static char line[1000];
int len, needs;
needs = 0;
for (;;) {
struct object *o;
unsigned char dummy[20], *sha1_buf;
len = packet_read_line(0, line, sizeof(line));
reset_timeout();
if (!len)
return needs;
sha1_buf = dummy;
if (needs == MAX_NEEDS) {
fprintf(stderr,
"warning: supporting only a max of %d requests. "
"sending everything instead.\n",
MAX_NEEDS);
}
else if (needs < MAX_NEEDS)
sha1_buf = needs_sha1[needs];
if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
die("git-upload-pack: protocol error, "
"expected to get sha, not '%s'", line);
if (strstr(line+45, "multi_ack"))
multi_ack = 1;
/* We have sent all our refs already, and the other end
* should have chosen out of them; otherwise they are
* asking for nonsense.
*
* Hmph. We may later want to allow "want" line that
* asks for something like "master~10" (symbolic)...
* would it make sense? I don't know.
*/
o = lookup_object(sha1_buf);
if (!o || !(o->flags & OUR_REF))
die("git-upload-pack: not our ref %s", line+5);
if (!(o->flags & WANTED)) {
o->flags |= WANTED;
needs++;
}
}
}
static int send_ref(const char *refname, const unsigned char *sha1)
{
static char *capabilities = "multi_ack";
struct object *o = parse_object(sha1);
if (capabilities)
packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
0, capabilities);
else
packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
capabilities = NULL;
if (!(o->flags & OUR_REF)) {
o->flags |= OUR_REF;
nr_our_refs++;
}
if (o->type == tag_type) {
o = deref_tag(o, refname, 0);
packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
}
return 0;
}
static int upload_pack(void)
{
reset_timeout();
head_ref(send_ref);
for_each_ref(send_ref);
packet_flush(1);
nr_needs = receive_needs();
if (!nr_needs)
return 0;
get_common_commits();
create_pack_file();
return 0;
}
int main(int argc, char **argv)
{
char *dir;
int i;
int strict = 0;
for (i = 1; i < argc; i++) {
char *arg = argv[i];
if (arg[0] != '-')
break;
if (!strcmp(arg, "--strict")) {
strict = 1;
continue;
}
if (!strncmp(arg, "--timeout=", 10)) {
timeout = atoi(arg+10);
continue;
}
if (!strcmp(arg, "--")) {
i++;
break;
}
}
if (i != argc-1)
usage(upload_pack_usage);
dir = argv[i];
if (!enter_repo(dir, strict))
die("'%s': unable to chdir or not a git archive", dir);
upload_pack();
return 0;
}