@matheusbsbs / matheus-bagliano / commits / 05e95155a1

upload-pack: send keepalive packets during pack computation

When upload-pack has started pack-objects, there may be a quiet period while pack-objects prepares the pack (i.e., counting objects and delta compression). Normally we would see (and send to the client) progress information, but if "--quiet" is in effect, pack-objects will produce nothing at all until the pack data is ready. On a large repository, this can take tens of seconds (or even minutes if the system is loaded or the repository is badly packed). Clients or intermediate proxies can sometimes give up in this situation, assuming that the server or connection has hung. This patch introduces a "keepalive" option; if upload-pack sees no data from pack-objects for a certain number of seconds, it will send an empty sideband data packet to let the other side know that we are still working on it. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Sep 8, 2013 at 05:01 UTC 05e95155a10fab3d3c495076e51b2ce79fa26cf3
2 files changed +35 -1
Documentation/config.txt
+11
@@ -2164,6 +2164,17 @@ uploadpack.allowtipsha1inwant::
2164 of a hidden ref (by default, such a request is rejected).
2165 see also `uploadpack.hiderefs`.
2166
2167 +uploadpack.keepalive::
2168 + When `upload-pack` has started `pack-objects`, there may be a
2169 + quiet period while `pack-objects` prepares the pack. Normally
2170 + it would output progress information, but if `--quiet` was used
2171 + for the fetch, `pack-objects` will output nothing at all until
2172 + the pack data begins. Some clients and networks may consider
2173 + the server to be hung and give up. Setting this option instructs
2174 + `upload-pack` to send an empty keepalive packet every
2175 + `uploadpack.keepalive` seconds. Setting this option to 0
2176 + disables keepalive packets entirely. The default is 0.
2177 +
2178 url.<base>.insteadOf::
2179 Any URL that starts with this value will be rewritten to
2180 start, instead, with <base>. In cases where some site serves a
upload-pack.c
+24 -1
@@ -40,6 +40,7 @@ static struct object_array have_obj;
40 static struct object_array want_obj;
41 static struct object_array extra_edge_obj;
42 static unsigned int timeout;
43 +static int keepalive = -1;
44 /* 0 for no sideband,
45 * otherwise maximum packet size (up to 65520 bytes).
46 */
@@ -200,6 +201,7 @@ static void create_pack_file(void)
201 while (1) {
202 struct pollfd pfd[2];
203 int pe, pu, pollsize;
204 + int ret;
205
206 reset_timeout();
207
@@ -222,7 +224,8 @@ static void create_pack_file(void)
224 if (!pollsize)
225 break;
226
225 - if (poll(pfd, pollsize, -1) < 0) {
227 + ret = poll(pfd, pollsize, 1000 * keepalive);
228 + if (ret < 0) {
229 if (errno != EINTR) {
230 error("poll failed, resuming: %s",
231 strerror(errno));
@@ -284,6 +287,21 @@ static void create_pack_file(void)
287 if (sz < 0)
288 goto fail;
289 }
290 +
291 + /*
292 + * We hit the keepalive timeout without saying anything; send
293 + * an empty message on the data sideband just to let the other
294 + * side know we're still working on it, but don't have any data
295 + * yet.
296 + *
297 + * If we don't have a sideband channel, there's no room in the
298 + * protocol to say anything, so those clients are just out of
299 + * luck.
300 + */
301 + if (!ret && use_sideband) {
302 + static const char buf[] = "0005\1";
303 + write_or_die(1, buf, 5);
304 + }
305 }
306
307 if (finish_command(&pack_objects)) {
@@ -785,6 +803,11 @@ static int upload_pack_config(const char *var, const char *value, void *unused)
803 {
804 if (!strcmp("uploadpack.allowtipsha1inwant", var))
805 allow_tip_sha1_in_want = git_config_bool(var, value);
806 + else if (!strcmp("uploadpack.keepalive", var)) {
807 + keepalive = git_config_int(var, value);
808 + if (!keepalive)
809 + keepalive = -1;
810 + }
811 return parse_hide_refs_config(var, value, "uploadpack");
812 }
813