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#include "cache.h"
#include "refs.h"
#include "pkt-line.h"
#include <sys/wait.h>
static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
static const char *unpacker = "git-unpack-objects";
static int show_ref(const char *path, const unsigned char *sha1)
{
packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
return 0;
}
static void write_head_info(void)
{
for_each_ref(show_ref);
}
struct command {
struct command *next;
unsigned char old_sha1[20];
unsigned char new_sha1[20];
char ref_name[0];
};
static struct command *commands = NULL;
static int is_all_zeroes(const char *hex)
{
int i;
for (i = 0; i < 40; i++)
if (*hex++ != '0')
return 0;
return 1;
}
static int verify_old_ref(const char *name, char *hex_contents)
{
int fd, ret;
char buffer[60];
if (is_all_zeroes(hex_contents))
return 0;
fd = open(name, O_RDONLY);
if (fd < 0)
return -1;
ret = read(fd, buffer, 40);
close(fd);
if (ret != 40)
return -1;
if (memcmp(buffer, hex_contents, 40))
return -1;
return 0;
}
static void update(const char *name, unsigned char *old_sha1, unsigned char *new_sha1)
{
char new_hex[60], *old_hex, *lock_name;
int newfd, namelen, written;
namelen = strlen(name);
lock_name = xmalloc(namelen + 10);
memcpy(lock_name, name, namelen);
memcpy(lock_name + namelen, ".lock", 6);
strcpy(new_hex, sha1_to_hex(new_sha1));
old_hex = sha1_to_hex(old_sha1);
if (!has_sha1_file(new_sha1))
die("unpack should have generated %s, but I can't find it!", new_hex);
newfd = open(lock_name, O_CREAT | O_EXCL | O_WRONLY, 0644);
if (newfd < 0)
die("unable to create %s (%s)", lock_name, strerror(errno));
/* Write the ref with an ending '\n' */
new_hex[40] = '\n';
new_hex[41] = 0;
written = write(newfd, new_hex, 41);
/* Remove the '\n' again */
new_hex[40] = 0;
close(newfd);
if (written != 41) {
unlink(lock_name);
die("unable to write %s", lock_name);
}
if (verify_old_ref(name, old_hex) < 0) {
unlink(lock_name);
die("%s changed during push", name);
}
if (rename(lock_name, name) < 0) {
unlink(lock_name);
die("unable to replace %s", name);
}
fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
}
/*
* This gets called after(if) we've successfully
* unpacked the data payload.
*/
static void execute_commands(void)
{
struct command *cmd = commands;
while (cmd) {
update(cmd->ref_name, cmd->old_sha1, cmd->new_sha1);
cmd = cmd->next;
}
}
static void read_head_info(void)
{
struct command **p = &commands;
for (;;) {
static char line[1000];
unsigned char old_sha1[20], new_sha1[20];
struct command *cmd;
int len;
len = packet_read_line(0, line, sizeof(line));
if (!len)
break;
if (line[len-1] == '\n')
line[--len] = 0;
if (len < 83 ||
line[40] != ' ' ||
line[81] != ' ' ||
get_sha1_hex(line, old_sha1) ||
get_sha1_hex(line + 41, new_sha1))
die("protocol error: expected old/new/ref, got '%s'", line);
cmd = xmalloc(sizeof(struct command) + len - 80);
memcpy(cmd->old_sha1, old_sha1, 20);
memcpy(cmd->new_sha1, new_sha1, 20);
memcpy(cmd->ref_name, line + 82, len - 81);
cmd->next = NULL;
*p = cmd;
p = &cmd->next;
}
}
static void unpack(void)
{
pid_t pid = fork();
if (pid < 0)
die("unpack fork failed");
if (!pid) {
execlp(unpacker, unpacker, NULL);
die("unpack execute failed");
}
for (;;) {
int status, code;
int retval = waitpid(pid, &status, 0);
if (retval < 0) {
if (errno == EINTR)
continue;
die("waitpid failed (%s)", strerror(retval));
}
if (retval != pid)
die("waitpid is confused");
if (WIFSIGNALED(status))
die("%s died of signal %d", unpacker, WTERMSIG(status));
if (!WIFEXITED(status))
die("%s died out of really strange complications", unpacker);
code = WEXITSTATUS(status);
if (code)
die("%s exited with error code %d", unpacker, code);
return;
}
}
int main(int argc, char **argv)
{
int i;
const char *dir = NULL;
argv++;
for (i = 1; i < argc; i++) {
const char *arg = *argv++;
if (*arg == '-') {
/* Do flag handling here */
usage(receive_pack_usage);
}
if (dir)
usage(receive_pack_usage);
dir = arg;
}
if (!dir)
usage(receive_pack_usage);
/* chdir to the directory. If that fails, try appending ".git" */
if (chdir(dir) < 0) {
static char path[PATH_MAX];
snprintf(path, sizeof(path), "%s.git", dir);
if (chdir(path) < 0)
die("unable to cd to %s", dir);
}
/* If we have a ".git" directory, chdir to it */
chdir(".git");
setenv("GIT_DIR", ".", 1);
if (access("objects", X_OK) < 0 || access("refs/heads", X_OK) < 0)
die("%s doesn't appear to be a git directory", dir);
write_head_info();
/* EOF */
packet_flush(1);
read_head_info();
if (commands) {
unpack();
execute_commands();
}
return 0;
}
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