Merge git://git.kernel.org/pub/scm/gitk/gitk
[git] / lockfile.c
1 /*
2  * Copyright (c) 2005, Junio C Hamano
3  */
4 #include <signal.h>
5 #include "cache.h"
6
7 static struct lock_file *lock_file_list;
8
9 static void remove_lock_file(void)
10 {
11         while (lock_file_list) {
12                 if (lock_file_list->filename[0])
13                         unlink(lock_file_list->filename);
14                 lock_file_list = lock_file_list->next;
15         }
16 }
17
18 static void remove_lock_file_on_signal(int signo)
19 {
20         remove_lock_file();
21         signal(SIGINT, SIG_DFL);
22         raise(signo);
23 }
24
25 int hold_lock_file_for_update(struct lock_file *lk, const char *path)
26 {
27         int fd;
28         sprintf(lk->filename, "%s.lock", path);
29         fd = open(lk->filename, O_RDWR | O_CREAT | O_EXCL, 0666);
30         if (fd >=0 && !lk->next) {
31                 lk->next = lock_file_list;
32                 lock_file_list = lk;
33                 signal(SIGINT, remove_lock_file_on_signal);
34                 atexit(remove_lock_file);
35         }
36         return fd;
37 }
38
39 int commit_lock_file(struct lock_file *lk)
40 {
41         char result_file[PATH_MAX];
42         int i;
43         strcpy(result_file, lk->filename);
44         i = strlen(result_file) - 5; /* .lock */
45         result_file[i] = 0;
46         i = rename(lk->filename, result_file);
47         lk->filename[0] = 0;
48         return i;
49 }
50
51 void rollback_lock_file(struct lock_file *lk)
52 {
53         if (lk->filename[0])
54                 unlink(lk->filename);
55         lk->filename[0] = 0;
56 }
57