xref: /dragonfly/sbin/hammer/cycle.c (revision 9db4b353)
1 /*
2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $DragonFly: src/sbin/hammer/cycle.c,v 1.2 2008/05/12 21:17:16 dillon Exp $
35  */
36 
37 #include "hammer.h"
38 
39 int64_t
40 hammer_get_cycle(int64_t default_obj_id)
41 {
42 	int64_t obj_id;
43 	FILE *fp;
44 
45 	if (CyclePath && (fp = fopen(CyclePath, "r")) != NULL) {
46 		if (fscanf(fp, "%llx\n", &obj_id) != 1) {
47 			obj_id = default_obj_id;
48 			fprintf(stderr, "Warning: malformed obj_id in %s\n",
49 				CyclePath);
50 		}
51 		fclose(fp);
52 	} else {
53 		obj_id = default_obj_id;
54 	}
55 	return(obj_id);
56 }
57 
58 void
59 hammer_set_cycle(int64_t obj_id)
60 {
61 	FILE *fp;
62 
63 	if ((fp = fopen(CyclePath, "w")) != NULL) {
64 		fprintf(fp, "%016llx\n", obj_id);
65 		fclose(fp);
66 	} else {
67 		fprintf(stderr, "Warning: Unable to write to %s: %s\n",
68 			CyclePath, strerror(errno));
69 	}
70 }
71 
72 void
73 hammer_reset_cycle(void)
74 {
75 	remove(CyclePath);
76 }
77 
78