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#include "cache.h"
#include "refs.h"
#include "pkt-line.h"
static const char fetch_pack_usage[] = "git-fetch-pack [host:]directory [heads]* < mycommitlist";
static const char *exec = "git-upload-pack";
static int get_ack(int fd, unsigned char *result_sha1)
{
static char line[1000];
int len = packet_read_line(fd, line, sizeof(line));
if (!len)
die("git-fetch-pack: expected ACK/NAK, got EOF");
if (line[len-1] == '\n')
line[--len] = 0;
if (!strcmp(line, "NAK"))
return 0;
if (!strncmp(line, "ACK ", 3)) {
if (!get_sha1_hex(line+4, result_sha1))
return 1;
}
die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
}
static int find_common(int fd[2], unsigned char *result_sha1, unsigned char *remote)
{
static char line[1000];
int count = 0, flushes = 0;
packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
packet_flush(fd[1]);
while (fgets(line, sizeof(line), stdin) != 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 (!(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))
return 0;
flushes--;
}
}
flushes++;
packet_flush(fd[1]);
while (flushes) {
flushes--;
if (get_ack(fd[0], result_sha1))
return 0;
}
return -1;
}
static int get_old_sha1(const char *refname, unsigned char *sha1)
{
static char pathname[PATH_MAX];
const char *git_dir;
int fd, ret;
git_dir = gitenv(GIT_DIR_ENVIRONMENT) ? : DEFAULT_GIT_DIR_ENVIRONMENT;
snprintf(pathname, sizeof(pathname), "%s/%s", git_dir, refname);
fd = open(pathname, O_RDONLY);
ret = -1;
if (fd >= 0) {
char buffer[60];
if (read(fd, buffer, sizeof(buffer)) >= 40)
ret = get_sha1_hex(buffer, sha1);
close(fd);
}
return ret;
}
static int check_ref(const char *refname, const unsigned char *sha1)
{
unsigned char mysha1[20];
char oldhex[41];
if (get_old_sha1(refname, mysha1) < 0)
memset(mysha1, 0, 20);
if (!memcmp(sha1, mysha1, 20)) {
printf("%s: unchanged\n", refname);
return 0;
}
memcpy(oldhex, sha1_to_hex(mysha1), 41);
printf("%s: %s (%s)\n", refname, sha1_to_hex(sha1), oldhex);
return 1;
}
static int get_remote_heads(int fd, int nr_match, char **match, unsigned char *result)
{
int count = 0;
for (;;) {
static char line[1000];
unsigned char sha1[20];
char *refname;
int len;
len = packet_read_line(fd, line, sizeof(line));
if (!len)
break;
if (line[len-1] == '\n')
line[--len] = 0;
if (len < 42 || get_sha1_hex(line, sha1))
die("git-fetch-pack: protocol error - expected ref descriptor, got '%sä'", line);
refname = line+41;
if (nr_match && !path_match(refname, nr_match, match))
continue;
if (check_ref(refname, sha1)) {
count++;
memcpy(result, sha1, 20);
}
}
return count;
}
static int fetch_pack(int fd[2], int nr_match, char **match)
{
unsigned char sha1[20], remote[20];
int heads;
heads = get_remote_heads(fd[0], nr_match, match, remote);
if (heads != 1) {
packet_flush(fd[1]);
die(heads ? "multiple remote heads" : "no matching remote head");
}
if (find_common(fd, sha1, remote) < 0)
die("git-fetch-pack: no common commits");
close(fd[1]);
dup2(fd[0], 0);
close(fd[0]);
execlp("git-unpack-objects", "git-unpack-objects", NULL);
die("git-unpack-objects exec failed");
}
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 == '-') {
/* Arguments go here */
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;
}
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