Merge branch 'js/color-diff'
[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 static int lock_file(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 (0 <= fd) {
31                 if (!lk->next) {
32                         lk->next = lock_file_list;
33                         lock_file_list = lk;
34                         signal(SIGINT, remove_lock_file_on_signal);
35                         atexit(remove_lock_file);
36                 }
37                 if (adjust_shared_perm(lk->filename))
38                         return error("cannot fix permission bits on %s",
39                                      lk->filename);
40         }
41         return fd;
42 }
43
44 int hold_lock_file_for_update(struct lock_file *lk, const char *path, int die_on_error)
45 {
46         int fd = lock_file(lk, path);
47         if (fd < 0 && die_on_error)
48                 die("unable to create '%s': %s", path, strerror(errno));
49         return fd;
50 }
51
52 int commit_lock_file(struct lock_file *lk)
53 {
54         char result_file[PATH_MAX];
55         int i;
56         strcpy(result_file, lk->filename);
57         i = strlen(result_file) - 5; /* .lock */
58         result_file[i] = 0;
59         i = rename(lk->filename, result_file);
60         lk->filename[0] = 0;
61         return i;
62 }
63
64 void rollback_lock_file(struct lock_file *lk)
65 {
66         if (lk->filename[0])
67                 unlink(lk->filename);
68         lk->filename[0] = 0;
69 }
70