2006/9/10, Junio C Hamano <junkio@xxxxxxx>:
Using the refactored sideband code from existing upload-pack protocol,
this lets the error condition and status output sent from the remote
process to be shown locally.
Signed-off-by: Junio C Hamano <junkio@xxxxxxx>
---
* This does it in a "stupid" way. Ideally, write(2) to fd 1
and 2 in each archiver backend could be wrapped with
something like upload-pack.c::send_client_data() that does
straight write(2) to the original destination when it is not
driven by upload-pack, or use send_sideband() when it is, and
that way we can lose two pipes and the multiplexer process.
Well I started that part the same way you do because I liked the fact
that archiver backend implementation needn't to know how to send out
data. It's totaly transparent for it. It just need to write its
payload on stdout.
builtin-archive.c | 24 ++++++++++--
builtin-upload-archive.c | 92 +++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 108 insertions(+), 8 deletions(-)
[snip]
+int cmd_upload_archive(int argc, const char **argv, const char *prefix)
+{
+ pid_t writer;
+ int fd1[2], fd2[2];
+ /*
+ * Set up sideband subprocess.
+ *
+ * We (parent) monitor and read from child, sending its fd#1 and fd#2
+ * multiplexed out to our fd#1. If the child dies, we tell the other
+ * end over channel #3.
+ */
+ if (pipe(fd1) < 0 || pipe(fd2) < 0) {
+ int err = errno;
+ packet_write(1, "NACK pipe failed on the remote side\n");
+ die("upload-archive: %s", strerror(err));
+ }
+ writer = fork();
+ if (writer < 0) {
+ int err = errno;
+ packet_write(1, "NACK fork failed on the remote side\n");
+ die("upload-archive: %s", strerror(err));
+ }
+ if (!writer) {
+ /* child - connect fd#1 and fd#2 to the pipe */
+ dup2(fd1[1], 1);
+ dup2(fd2[1], 2);
+ close(fd1[1]); close(fd2[1]);
+ close(fd1[0]); close(fd2[0]); /* we do not read from pipe */
+
+ exit(run_upload_archive(argc, argv, prefix));
+ }
+
+ /* parent - read from child, multiplex and send out to fd#1 */
+ close(fd1[1]); close(fd2[1]); /* we do not write to pipe */
packet_write(1, "ACK\n");
packet_flush(1);
- return ar.write_archive(&ar.args);
-}
+ while (1) {
+ struct pollfd pfd[2];
+ char buf[16384];
+ ssize_t sz;
+ pid_t pid;
+ int status;
+
+ pfd[0].fd = fd1[0];
+ pfd[0].events = POLLIN;
+ pfd[1].fd = fd2[0];
+ pfd[1].events = POLLIN;
+ if (poll(pfd, 2, -1) < 0) {
+ if (errno != EINTR) {
+ error("poll failed resuming: %s",
+ strerror(errno));
+ sleep(1);
+ }
+ continue;
+ }
+ if (pfd[0].revents & (POLLIN|POLLHUP)) {
+ /* Data stream ready */
+ sz = read(pfd[0].fd, buf, sizeof(buf));
+ send_sideband(1, 1, buf, sz, DEFAULT_PACKET_MAX);
+ }
+ if (pfd[1].revents & (POLLIN|POLLHUP)) {
+ /* Status stream ready */
+ sz = read(pfd[1].fd, buf, sizeof(buf));
+ send_sideband(1, 2, buf, sz, DEFAULT_PACKET_MAX);
+ }
+ if (((pfd[0].revents | pfd[1].revents) & POLLHUP) == 0)
+ continue;
+ /* did it die? */
+ pid = waitpid(writer, &status, WNOHANG);
+ if (!pid) {
+ fprintf(stderr, "Hmph, HUP?\n");
+ continue;
+ }
+ if (!WIFEXITED(status) || WEXITSTATUS(status) > 0)
+ send_sideband(1, 3, deadchild, strlen(deadchild),
+ DEFAULT_PACKET_MAX);
+ packet_flush(1);
+ break;
+ }
+ return 0;
+}
Why all of this is part of upload-archive ? Shouldn't we put that code
in daemon.c ?
We could use a new service flag to ask daemon.c to start the service
with the sideband multiplexer process already setup and plugged with
the sercive is going to start ? Hence others future services could use
it.
--
Franck
-
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