git/upload-pack.c

181 lines
3.7 KiB
C
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#include "cache.h"
#include "refs.h"
#include "pkt-line.h"
static const char upload_pack_usage[] = "git-upload-pack <dir>";
#define MAX_HAS (16)
#define MAX_NEEDS (16)
static int nr_has = 0, nr_needs = 0;
static unsigned char has_sha1[MAX_HAS][20];
static unsigned char needs_sha1[MAX_NEEDS][20];
static int strip(char *line, int len)
{
if (len && line[len-1] == '\n')
line[--len] = 0;
return len;
}
static void create_pack_file(void)
{
int fd[2];
pid_t pid;
if (pipe(fd) < 0)
die("git-upload-pack: unable to create pipe");
pid = fork();
if (pid < 0)
die("git-upload-pack: unable to fork git-rev-list");
if (!pid) {
int i;
int args = nr_has + nr_needs + 5;
char **argv = xmalloc(args * sizeof(char *));
char *buf = xmalloc(args * 45);
char **p = argv;
dup2(fd[1], 1);
close(0);
close(fd[0]);
close(fd[1]);
*p++ = "git-rev-list";
*p++ = "--objects";
for (i = 0; i < nr_needs; i++) {
*p++ = buf;
memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
buf += 41;
}
for (i = 0; i < nr_has; i++) {
*p++ = buf;
*buf++ = '^';
memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
buf += 41;
}
*p++ = NULL;
execvp("git-rev-list", argv);
die("git-upload-pack: unable to exec git-rev-list");
}
dup2(fd[0], 0);
close(fd[0]);
close(fd[1]);
execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
die("git-upload-pack: unable to exec git-pack-objects");
}
static int got_sha1(char *hex, unsigned char *sha1)
{
int nr;
if (get_sha1_hex(hex, sha1))
die("git-upload-pack: expected SHA1 object, got '%s'", hex);
if (!has_sha1_file(sha1))
return 0;
nr = nr_has;
if (nr < MAX_HAS) {
memcpy(has_sha1[nr], sha1, 20);
nr_has = nr+1;
}
return 1;
}
static int get_common_commits(void)
{
static char line[1000];
unsigned char sha1[20];
int len;
for(;;) {
len = packet_read_line(0, line, sizeof(line));
if (!len) {
packet_write(1, "NAK\n");
continue;
}
len = strip(line, len);
if (!strncmp(line, "have ", 5)) {
if (got_sha1(line+5, sha1)) {
packet_write(1, "ACK %s\n", sha1_to_hex(sha1));
break;
}
continue;
}
if (!strcmp(line, "done")) {
packet_write(1, "NAK\n");
return -1;
}
die("git-upload-pack: expected SHA1 list, got '%s'", line);
}
for (;;) {
len = packet_read_line(0, line, sizeof(line));
if (!len)
continue;
len = strip(line, len);
if (!strncmp(line, "have ", 5)) {
got_sha1(line+5, sha1);
continue;
}
if (!strcmp(line, "done"))
break;
die("git-upload-pack: expected SHA1 list, got '%s'", line);
}
return 0;
}
static int receive_needs(void)
{
static char line[1000];
int len, needs;
needs = 0;
for (;;) {
len = packet_read_line(0, line, sizeof(line));
if (!len)
return needs;
/*
* This is purely theoretical right now: git-fetch-pack only
* ever asks for a single HEAD
*/
if (needs >= MAX_NEEDS)
die("I'm only doing a max of %d requests", MAX_NEEDS);
if (strncmp("want ", line, 5) || get_sha1_hex(line+5, needs_sha1[needs]))
die("git-upload-pack: protocol error, expected to get sha, not '%s'", line);
needs++;
}
}
static int send_ref(const char *refname, const unsigned char *sha1)
{
packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
return 0;
}
static int upload_pack(void)
{
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)
{
const char *dir;
if (argc != 2)
usage(upload_pack_usage);
dir = argv[1];
if (chdir(dir))
die("git-upload-pack unable to chdir to %s", dir);
chdir(".git");
if (access("objects", X_OK) || access("refs", X_OK))
die("git-upload-pack: %s doesn't seem to be a git archive", dir);
setenv("GIT_DIR", ".", 1);
upload_pack();
return 0;
}