Merge git://repo.or.cz/git-gui into maint
[git] / lockfile.c
1 /*
2  * Copyright (c) 2005, Junio C Hamano
3  */
4 #include "cache.h"
5
6 static struct lock_file *lock_file_list;
7
8 static void remove_lock_file(void)
9 {
10         while (lock_file_list) {
11                 if (lock_file_list->filename[0])
12                         unlink(lock_file_list->filename);
13                 lock_file_list = lock_file_list->next;
14         }
15 }
16
17 static void remove_lock_file_on_signal(int signo)
18 {
19         remove_lock_file();
20         signal(SIGINT, SIG_DFL);
21         raise(signo);
22 }
23
24 static int lock_file(struct lock_file *lk, const char *path)
25 {
26         int fd;
27         sprintf(lk->filename, "%s.lock", path);
28         fd = open(lk->filename, O_RDWR | O_CREAT | O_EXCL, 0666);
29         if (0 <= fd) {
30                 if (!lk->on_list) {
31                         lk->next = lock_file_list;
32                         lock_file_list = lk;
33                         lk->on_list = 1;
34                 }
35                 if (lock_file_list) {
36                         signal(SIGINT, remove_lock_file_on_signal);
37                         atexit(remove_lock_file);
38                 }
39                 if (adjust_shared_perm(lk->filename))
40                         return error("cannot fix permission bits on %s",
41                                      lk->filename);
42         }
43         else
44                 lk->filename[0] = 0;
45         return fd;
46 }
47
48 int hold_lock_file_for_update(struct lock_file *lk, const char *path, int die_on_error)
49 {
50         int fd = lock_file(lk, path);
51         if (fd < 0 && die_on_error)
52                 die("unable to create '%s.lock': %s", path, strerror(errno));
53         return fd;
54 }
55
56 int commit_lock_file(struct lock_file *lk)
57 {
58         char result_file[PATH_MAX];
59         int i;
60         strcpy(result_file, lk->filename);
61         i = strlen(result_file) - 5; /* .lock */
62         result_file[i] = 0;
63         i = rename(lk->filename, result_file);
64         lk->filename[0] = 0;
65         return i;
66 }
67
68 void rollback_lock_file(struct lock_file *lk)
69 {
70         if (lk->filename[0])
71                 unlink(lk->filename);
72         lk->filename[0] = 0;
73 }
74