Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging
[qemu/ar7.git] / util / id.c
blobded41c5025e4a0a1c3422469ff723b91d8c210c2
1 /*
2  * Dealing with identifiers
3  *
4  * Copyright (C) 2014 Red Hat, Inc.
5  *
6  * Authors:
7  *  Markus Armbruster <armbru@redhat.com>,
8  *
9  * This work is licensed under the terms of the GNU LGPL, version 2.1
10  * or later.  See the COPYING.LIB file in the top-level directory.
11  */
13 #include "qemu/osdep.h"
14 #include "qemu/ctype.h"
15 #include "qemu/id.h"
17 bool id_wellformed(const char *id)
19     int i;
21     if (!qemu_isalpha(id[0])) {
22         return false;
23     }
24     for (i = 1; id[i]; i++) {
25         if (!qemu_isalnum(id[i]) && !strchr("-._", id[i])) {
26             return false;
27         }
28     }
29     return true;
32 #define ID_SPECIAL_CHAR '#'
34 static const char *const id_subsys_str[ID_MAX] = {
35     [ID_QDEV]  = "qdev",
36     [ID_BLOCK] = "block",
37     [ID_CHR] = "chr",
38     [ID_NET] = "net",
42  *  Generates an ID of the form PREFIX SUBSYSTEM NUMBER
43  *  where:
44  *
45  *  - PREFIX is the reserved character '#'
46  *  - SUBSYSTEM identifies the subsystem creating the ID
47  *  - NUMBER is a decimal number unique within SUBSYSTEM.
48  *
49  *    Example: "#block146"
50  *
51  * Note that these IDs do not satisfy id_wellformed().
52  *
53  * The caller is responsible for freeing the returned string with g_free()
54  */
55 char *id_generate(IdSubSystems id)
57     static uint64_t id_counters[ID_MAX];
58     uint32_t rnd;
60     assert(id < ARRAY_SIZE(id_subsys_str));
61     assert(id_subsys_str[id]);
63     rnd = g_random_int_range(0, 100);
65     return g_strdup_printf("%c%s%" PRIu64 "%02" PRId32, ID_SPECIAL_CHAR,
66                                                         id_subsys_str[id],
67                                                         id_counters[id]++,
68                                                         rnd);