git/upload-pack.c
Junio C Hamano 583b7ea31b upload-pack/fetch-pack: support side-band communication
This implements a protocol extension between fetch-pack and
upload-pack to allow stderr stream from upload-pack (primarily
used for the progress bar display) to be passed back.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-21 02:50:32 -07:00

516 lines
11 KiB
C

#include "cache.h"
#include "refs.h"
#include "pkt-line.h"
#include "tag.h"
#include "object.h"
#include "commit.h"
#include "exec_cmd.h"
#include <signal.h>
#include <sys/poll.h>
#include <sys/wait.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 int use_thin_pack = 0;
static unsigned char has_sha1[MAX_HAS][20];
static unsigned char needs_sha1[MAX_NEEDS][20];
static unsigned int timeout = 0;
static int use_sideband = 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;
}
#define PACKET_MAX 1000
static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
{
ssize_t ssz;
const char *p;
if (!data) {
if (!use_sideband)
return 0;
packet_flush(1);
}
if (!use_sideband) {
if (fd == 3)
/* emergency quit */
fd = 2;
return safe_write(fd, data, sz);
}
p = data;
ssz = sz;
while (sz) {
unsigned n;
char hdr[5];
n = sz;
if (PACKET_MAX - 5 < n)
n = PACKET_MAX - 5;
sprintf(hdr, "%04x", n + 5);
hdr[4] = fd;
safe_write(1, hdr, 5);
safe_write(1, p, n);
p += n;
sz -= n;
}
return ssz;
}
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 == nr_needs && !nr_has);
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;
char *buf;
char **p;
if (create_full_pack) {
args = 10;
use_thin_pack = 0; /* no point doing it */
}
else
args = nr_has + nr_needs + 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 || 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;
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", 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;
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");
}
send_client_data(1, NULL, 0);
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)
{
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 == TYPE_COMMIT) {
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;
if (strstr(line+45, "thin-pack"))
use_thin_pack = 1;
if (strstr(line+45, "side-band"))
use_sideband = 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 thin-pack side-band";
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 == TYPE_TAG) {
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;
}