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/*
* Copyright (c) 2005, Junio C Hamano
*/
#include "cache.h"
static struct lock_file *lock_file_list;
static const char *alternate_index_output;
static void remove_lock_file(void)
{
pid_t me = getpid();
while (lock_file_list) {
if (lock_file_list->owner == me &&
lock_file_list->filename[0])
unlink(lock_file_list->filename);
lock_file_list = lock_file_list->next;
}
}
static void remove_lock_file_on_signal(int signo)
{
remove_lock_file();
signal(SIGINT, SIG_DFL);
raise(signo);
}
static int lock_file(struct lock_file *lk, const char *path)
{
int fd;
sprintf(lk->filename, "%s.lock", path);
fd = open(lk->filename, O_RDWR | O_CREAT | O_EXCL, 0666);
if (0 <= fd) {
lk->owner = getpid();
if (!lk->on_list) {
lk->next = lock_file_list;
lock_file_list = lk;
lk->on_list = 1;
}
if (lock_file_list) {
signal(SIGINT, remove_lock_file_on_signal);
atexit(remove_lock_file);
}
if (adjust_shared_perm(lk->filename))
return error("cannot fix permission bits on %s",
lk->filename);
}
else
lk->filename[0] = 0;
return fd;
}
int hold_lock_file_for_update(struct lock_file *lk, const char *path, int die_on_error)
{
int fd = lock_file(lk, path);
if (fd < 0 && die_on_error)
die("unable to create '%s.lock': %s", path, strerror(errno));
return fd;
}
int commit_lock_file(struct lock_file *lk)
{
char result_file[PATH_MAX];
int i;
strcpy(result_file, lk->filename);
i = strlen(result_file) - 5; /* .lock */
result_file[i] = 0;
i = rename(lk->filename, result_file);
lk->filename[0] = 0;
return i;
}
int hold_locked_index(struct lock_file *lk, int die_on_error)
{
return hold_lock_file_for_update(lk, get_index_file(), die_on_error);
}
void set_alternate_index_output(const char *name)
{
alternate_index_output = name;
}
int commit_locked_index(struct lock_file *lk)
{
if (alternate_index_output) {
int result = rename(lk->filename, alternate_index_output);
lk->filename[0] = 0;
return result;
}
else
return commit_lock_file(lk);
}
void rollback_lock_file(struct lock_file *lk)
{
if (lk->filename[0])
unlink(lk->filename);
lk->filename[0] = 0;
}
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