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git/upload-pack.c
Junio C Hamano 3fbe2d54d7 Merge branch 'jc/upload-pack' 
* jc/upload-pack:
  upload-pack: stop the other side when they have more roots than we do.
2006-11-24 02:34:27 -08:00

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#include <signal.h>
#include <sys/wait.h>
#include <sys/poll.h>
#include "cache.h"
#include "refs.h"
#include "pkt-line.h"
#include "sideband.h"
#include "tag.h"
#include "object.h"
#include "commit.h"
#include "exec_cmd.h"
static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
/* bits #0..7 in revision.h, #8..10 in commit.c */
#define THEY_HAVE (1u << 11)
#define OUR_REF (1u << 12)
#define WANTED (1u << 13)
#define COMMON_KNOWN (1u << 14)
#define REACHABLE (1u << 15)
static unsigned long oldest_have;
static int multi_ack, nr_our_refs;
static int use_thin_pack, use_ofs_delta;
static struct object_array have_obj;
static struct object_array want_obj;
static unsigned int timeout;
/* 0 for no sideband,
* otherwise maximum packet size (up to 65520 bytes).
*/
static int use_sideband;
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 ssize_t send_client_data(int fd, const char *data, ssize_t sz)
{
if (use_sideband)
return send_sideband(1, fd, data, sz, use_sideband);
if (fd == 3)
/* emergency quit */
fd = 2;
if (fd == 2) {
xwrite(fd, data, sz);
return sz;
}
return safe_write(fd, data, sz);
}
static void create_pack_file(void)
{
/* Pipes between rev-list to pack-objects, pack-objects to us
* and pack-objects error stream for progress bar.
*/
int lp_pipe[2], pu_pipe[2], pe_pipe[2];
pid_t pid_rev_list, pid_pack_objects;
int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
char data[8193], progress[128];
char abort_msg[] = "aborting due to possible repository "
"corruption on the remote side.";
int buffered = -1;
if (pipe(lp_pipe) < 0)
die("git-upload-pack: unable to create pipe");
pid_rev_list = fork();
if (pid_rev_list < 0)
die("git-upload-pack: unable to fork git-rev-list");
if (!pid_rev_list) {
int i;
int args;
const char **argv;
const char **p;
char *buf;
if (create_full_pack) {
args = 10;
use_thin_pack = 0; /* no point doing it */
}
else
args = have_obj.nr + want_obj.nr + 5;
p = xmalloc(args * sizeof(char *));
argv = (const char **) p;
buf = xmalloc(args * 45);
dup2(lp_pipe[1], 1);
close(0);
close(lp_pipe[0]);
close(lp_pipe[1]);
*p++ = "rev-list";
*p++ = use_thin_pack ? "--objects-edge" : "--objects";
if (create_full_pack)
*p++ = "--all";
else {
for (i = 0; i < want_obj.nr; i++) {
struct object *o = want_obj.objects[i].item;
*p++ = buf;
memcpy(buf, sha1_to_hex(o->sha1), 41);
buf += 41;
}
}
if (!create_full_pack)
for (i = 0; i < have_obj.nr; i++) {
struct object *o = have_obj.objects[i].item;
*p++ = buf;
*buf++ = '^';
memcpy(buf, sha1_to_hex(o->sha1), 41);
buf += 41;
}
*p++ = NULL;
execv_git_cmd(argv);
die("git-upload-pack: unable to exec git-rev-list");
}
if (pipe(pu_pipe) < 0)
die("git-upload-pack: unable to create pipe");
if (pipe(pe_pipe) < 0)
die("git-upload-pack: unable to create pipe");
pid_pack_objects = fork();
if (pid_pack_objects < 0) {
/* daemon sets things up to ignore TERM */
kill(pid_rev_list, SIGKILL);
die("git-upload-pack: unable to fork git-pack-objects");
}
if (!pid_pack_objects) {
dup2(lp_pipe[0], 0);
dup2(pu_pipe[1], 1);
dup2(pe_pipe[1], 2);
close(lp_pipe[0]);
close(lp_pipe[1]);
close(pu_pipe[0]);
close(pu_pipe[1]);
close(pe_pipe[0]);
close(pe_pipe[1]);
execl_git_cmd("pack-objects", "--stdout", "--progress",
use_ofs_delta ? "--delta-base-offset" : NULL,
NULL);
kill(pid_rev_list, SIGKILL);
die("git-upload-pack: unable to exec git-pack-objects");
}
close(lp_pipe[0]);
close(lp_pipe[1]);
/* We read from pe_pipe[0] to capture stderr output for
* progress bar, and pu_pipe[0] to capture the pack data.
*/
close(pe_pipe[1]);
close(pu_pipe[1]);
while (1) {
const char *who;
struct pollfd pfd[2];
pid_t pid;
int status;
ssize_t sz;
int pe, pu, pollsize;
reset_timeout();
pollsize = 0;
pe = pu = -1;
if (0 <= pu_pipe[0]) {
pfd[pollsize].fd = pu_pipe[0];
pfd[pollsize].events = POLLIN;
pu = pollsize;
pollsize++;
}
if (0 <= pe_pipe[0]) {
pfd[pollsize].fd = pe_pipe[0];
pfd[pollsize].events = POLLIN;
pe = pollsize;
pollsize++;
}
if (pollsize) {
if (poll(pfd, pollsize, -1) < 0) {
if (errno != EINTR) {
error("poll failed, resuming: %s",
strerror(errno));
sleep(1);
}
continue;
}
if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
/* Data ready; we keep the last byte
* to ourselves in case we detect
* broken rev-list, so that we can
* leave the stream corrupted. This
* is unfortunate -- unpack-objects
* would happily accept a valid pack
* data with trailing garbage, so
* appending garbage after we pass all
* the pack data is not good enough to
* signal breakage to downstream.
*/
char *cp = data;
ssize_t outsz = 0;
if (0 <= buffered) {
*cp++ = buffered;
outsz++;
}
sz = read(pu_pipe[0], cp,
sizeof(data) - outsz);
if (0 < sz)
;
else if (sz == 0) {
close(pu_pipe[0]);
pu_pipe[0] = -1;
}
else
goto fail;
sz += outsz;
if (1 < sz) {
buffered = data[sz-1] & 0xFF;
sz--;
}
else
buffered = -1;
sz = send_client_data(1, data, sz);
if (sz < 0)
goto fail;
}
if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
/* Status ready; we ship that in the side-band
* or dump to the standard error.
*/
sz = read(pe_pipe[0], progress,
sizeof(progress));
if (0 < sz)
send_client_data(2, progress, sz);
else if (sz == 0) {
close(pe_pipe[0]);
pe_pipe[0] = -1;
}
else
goto fail;
}
}
/* See if the children are still there */
if (pid_rev_list || pid_pack_objects) {
pid = waitpid(-1, &status, WNOHANG);
if (!pid)
continue;
who = ((pid == pid_rev_list) ? "git-rev-list" :
(pid == pid_pack_objects) ? "git-pack-objects" :
NULL);
if (!who) {
if (pid < 0) {
error("git-upload-pack: %s",
strerror(errno));
goto fail;
}
error("git-upload-pack: we weren't "
"waiting for %d", pid);
continue;
}
if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
error("git-upload-pack: %s died with error.",
who);
goto fail;
}
if (pid == pid_rev_list)
pid_rev_list = 0;
if (pid == pid_pack_objects)
pid_pack_objects = 0;
if (pid_rev_list || pid_pack_objects)
continue;
}
/* both died happily */
if (pollsize)
continue;
/* flush the data */
if (0 <= buffered) {
data[0] = buffered;
sz = send_client_data(1, data, 1);
if (sz < 0)
goto fail;
fprintf(stderr, "flushed.\n");
}
if (use_sideband)
packet_flush(1);
return;
}
fail:
if (pid_pack_objects)
kill(pid_pack_objects, SIGKILL);
if (pid_rev_list)
kill(pid_rev_list, SIGKILL);
send_client_data(3, abort_msg, sizeof(abort_msg));
die("git-upload-pack: %s", abort_msg);
}
static int got_sha1(char *hex, unsigned char *sha1)
{
struct object *o;
int we_knew_they_have = 0;
if (get_sha1_hex(hex, sha1))
die("git-upload-pack: expected SHA1 object, got '%s'", hex);
if (!has_sha1_file(sha1))
return -1;
o = lookup_object(sha1);
if (!(o && o->parsed))
o = parse_object(sha1);
if (!o)
die("oops (%s)", sha1_to_hex(sha1));
if (o->type == OBJ_COMMIT) {
struct commit_list *parents;
struct commit *commit = (struct commit *)o;
if (o->flags & THEY_HAVE)
we_knew_they_have = 1;
else
o->flags |= THEY_HAVE;
if (!oldest_have || (commit->date < oldest_have))
oldest_have = commit->date;
for (parents = commit->parents;
parents;
parents = parents->next)
parents->item->object.flags |= THEY_HAVE;
}
if (!we_knew_they_have) {
add_object_array(o, NULL, &have_obj);
return 1;
}
return 0;
}
static int reachable(struct commit *want)
{
struct commit_list *work = NULL;
insert_by_date(want, &work);
while (work) {
struct commit_list *list = work->next;
struct commit *commit = work->item;
free(work);
work = list;
if (commit->object.flags & THEY_HAVE) {
want->object.flags |= COMMON_KNOWN;
break;
}
if (!commit->object.parsed)
parse_object(commit->object.sha1);
if (commit->object.flags & REACHABLE)
continue;
commit->object.flags |= REACHABLE;
if (commit->date < oldest_have)
continue;
for (list = commit->parents; list; list = list->next) {
struct commit *parent = list->item;
if (!(parent->object.flags & REACHABLE))
insert_by_date(parent, &work);
}
}
want->object.flags |= REACHABLE;
clear_commit_marks(want, REACHABLE);
free_commit_list(work);
return (want->object.flags & COMMON_KNOWN);
}
static int ok_to_give_up(void)
{
int i;
if (!have_obj.nr)
return 0;
for (i = 0; i < want_obj.nr; i++) {
struct object *want = want_obj.objects[i].item;
if (want->flags & COMMON_KNOWN)
continue;
want = deref_tag(want, "a want line", 0);
if (!want || want->type != OBJ_COMMIT) {
/* no way to tell if this is reachable by
* looking at the ancestry chain alone, so
* leave a note to ourselves not to worry about
* this object anymore.
*/
want_obj.objects[i].item->flags |= COMMON_KNOWN;
continue;
}
if (!reachable((struct commit *)want))
return 0;
}
return 1;
}
static int get_common_commits(void)
{
static char line[1000];
unsigned char sha1[20];
char hex[41], last_hex[41];
int len;
track_object_refs = 0;
save_commit_buffer = 0;
for(;;) {
len = packet_read_line(0, line, sizeof(line));
reset_timeout();
if (!len) {
if (have_obj.nr == 0 || multi_ack)
packet_write(1, "NAK\n");
continue;
}
len = strip(line, len);
if (!strncmp(line, "have ", 5)) {
switch (got_sha1(line+5, sha1)) {
case -1: /* they have what we do not */
if (multi_ack && ok_to_give_up())
packet_write(1, "ACK %s continue\n",
sha1_to_hex(sha1));
break;
default:
memcpy(hex, sha1_to_hex(sha1), 41);
if (multi_ack) {
const char *msg = "ACK %s continue\n";
packet_write(1, msg, hex);
memcpy(last_hex, hex, 41);
}
else if (have_obj.nr == 1)
packet_write(1, "ACK %s\n", hex);
break;
}
continue;
}
if (!strcmp(line, "done")) {
if (have_obj.nr > 0) {
if (multi_ack)
packet_write(1, "ACK %s\n", last_hex);
return 0;
}
packet_write(1, "NAK\n");
return -1;
}
die("git-upload-pack: expected SHA1 list, got '%s'", line);
}
}
static void receive_needs(void)
{
static char line[1000];
int len;
for (;;) {
struct object *o;
unsigned char sha1_buf[20];
len = packet_read_line(0, line, sizeof(line));
reset_timeout();
if (!len)
return;
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;
if (strstr(line+45, "thin-pack"))
use_thin_pack = 1;
if (strstr(line+45, "ofs-delta"))
use_ofs_delta = 1;
if (strstr(line+45, "side-band-64k"))
use_sideband = LARGE_PACKET_MAX;
else if (strstr(line+45, "side-band"))
use_sideband = DEFAULT_PACKET_MAX;
/* 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;
add_object_array(o, NULL, &want_obj);
}
}
}
static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
{
static const char *capabilities = "multi_ack thin-pack side-band side-band-64k ofs-delta";
struct object *o = parse_object(sha1);
if (!o)
die("git-upload-pack: cannot find object %s:", sha1_to_hex(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 == OBJ_TAG) {
o = deref_tag(o, refname, 0);
packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
}
return 0;
}
static void upload_pack(void)
{
reset_timeout();
head_ref(send_ref, NULL);
for_each_ref(send_ref, NULL);
packet_flush(1);
receive_needs();
if (want_obj.nr) {
get_common_commits();
create_pack_file();
}
}
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;
}
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