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git/fetch-pack.c
Junio C Hamano 33b8303466 fetch-pack: start multi-head pulling.
This is a beginning of resurrecting the multi-head pulling support
for git-fetch-pack command.  The git-fetch-script wrapper still
only knows about fetching a single head, without renaming, so it is
not very useful unless you directly call git-fetch-pack itself yet.

It also fixes a longstanding obsolete description of how the command
discovers the list of local commits.
2005-08-12 10:38:21 -07:00

168 lines
3.7 KiB
C

#include "cache.h"
#include "refs.h"
#include "pkt-line.h"
#include <sys/wait.h>
static int quiet;
static int verbose;
static const char fetch_pack_usage[] =
"git-fetch-pack [-q] [-v] [--exec=upload-pack] [host:]directory <refs>...";
static const char *exec = "git-upload-pack";
static int find_common(int fd[2], unsigned char *result_sha1,
struct ref *refs)
{
static char line[1000];
int count = 0, flushes = 0, retval;
FILE *revs;
revs = popen("git-rev-list $(git-rev-parse --all)", "r");
if (!revs)
die("unable to run 'git-rev-list'");
while (refs) {
unsigned char *remote = refs->old_sha1;
if (verbose)
fprintf(stderr,
"want %s (%s)\n", sha1_to_hex(remote),
refs->name);
packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
refs = refs->next;
}
packet_flush(fd[1]);
flushes = 1;
retval = -1;
while (fgets(line, sizeof(line), revs) != NULL) {
unsigned char sha1[20];
if (get_sha1_hex(line, sha1))
die("git-fetch-pack: expected object name, got crud");
packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
if (verbose)
fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
if (!(31 & ++count)) {
packet_flush(fd[1]);
flushes++;
/*
* We keep one window "ahead" of the other side, and
* will wait for an ACK only on the next one
*/
if (count == 32)
continue;
if (get_ack(fd[0], result_sha1)) {
flushes = 0;
retval = 0;
if (verbose)
fprintf(stderr, "got ack\n");
break;
}
flushes--;
}
}
pclose(revs);
packet_write(fd[1], "done\n");
if (verbose)
fprintf(stderr, "done\n");
while (flushes) {
flushes--;
if (get_ack(fd[0], result_sha1)) {
if (verbose)
fprintf(stderr, "got ack\n");
return 0;
}
}
return retval;
}
static int fetch_pack(int fd[2], int nr_match, char **match)
{
struct ref *ref;
unsigned char sha1[20];
int status;
pid_t pid;
get_remote_heads(fd[0], &ref, nr_match, match);
if (!ref) {
packet_flush(fd[1]);
die("no matching remote head");
}
if (find_common(fd, sha1, ref) < 0)
fprintf(stderr, "warning: no common commits\n");
pid = fork();
if (pid < 0)
die("git-fetch-pack: unable to fork off git-unpack-objects");
if (!pid) {
dup2(fd[0], 0);
close(fd[0]);
close(fd[1]);
execlp("git-unpack-objects", "git-unpack-objects",
quiet ? "-q" : NULL, NULL);
die("git-unpack-objects exec failed");
}
close(fd[0]);
close(fd[1]);
while (waitpid(pid, &status, 0) < 0) {
if (errno != EINTR)
die("waiting for git-unpack-objects: %s", strerror(errno));
}
if (WIFEXITED(status)) {
int code = WEXITSTATUS(status);
if (code)
die("git-unpack-objects died with error code %d", code);
while (ref) {
printf("%s %s\n",
sha1_to_hex(ref->old_sha1), ref->name);
ref = ref->next;
}
return 0;
}
if (WIFSIGNALED(status)) {
int sig = WTERMSIG(status);
die("git-unpack-objects died of signal %d", sig);
}
die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
}
int main(int argc, char **argv)
{
int i, ret, nr_heads;
char *dest = NULL, **heads;
int fd[2];
pid_t pid;
nr_heads = 0;
heads = NULL;
for (i = 1; i < argc; i++) {
char *arg = argv[i];
if (*arg == '-') {
if (!strncmp("--exec=", arg, 7)) {
exec = arg + 7;
continue;
}
if (!strcmp("-q", arg)) {
quiet = 1;
continue;
}
if (!strcmp("-v", arg)) {
verbose = 1;
continue;
}
usage(fetch_pack_usage);
}
dest = arg;
heads = argv + i + 1;
nr_heads = argc - i - 1;
break;
}
if (!dest)
usage(fetch_pack_usage);
pid = git_connect(fd, dest, exec);
if (pid < 0)
return 1;
ret = fetch_pack(fd, nr_heads, heads);
close(fd[0]);
close(fd[1]);
finish_connect(pid);
return ret;
}