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 | */ |
12 | |
13 | #include "qemu/osdep.h" |
14 | #include "qemu/ctype.h" |
15 | #include "qemu/id.h" |
16 | |
17 | bool id_wellformed(const char *id) |
18 | { |
19 | int i; |
20 | |
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; |
30 | } |
31 | |
32 | #define ID_SPECIAL_CHAR '#' |
33 | |
34 | static const char *const id_subsys_str[ID_MAX] = { |
35 | [ID_QDEV] = "qdev" , |
36 | [ID_BLOCK] = "block" , |
37 | }; |
38 | |
39 | /* |
40 | * Generates an ID of the form PREFIX SUBSYSTEM NUMBER |
41 | * where: |
42 | * |
43 | * - PREFIX is the reserved character '#' |
44 | * - SUBSYSTEM identifies the subsystem creating the ID |
45 | * - NUMBER is a decimal number unique within SUBSYSTEM. |
46 | * |
47 | * Example: "#block146" |
48 | * |
49 | * Note that these IDs do not satisfy id_wellformed(). |
50 | * |
51 | * The caller is responsible for freeing the returned string with g_free() |
52 | */ |
53 | char *id_generate(IdSubSystems id) |
54 | { |
55 | static uint64_t id_counters[ID_MAX]; |
56 | uint32_t rnd; |
57 | |
58 | assert(id < ARRAY_SIZE(id_subsys_str)); |
59 | assert(id_subsys_str[id]); |
60 | |
61 | rnd = g_random_int_range(0, 100); |
62 | |
63 | return g_strdup_printf("%c%s%" PRIu64 "%02" PRId32, ID_SPECIAL_CHAR, |
64 | id_subsys_str[id], |
65 | id_counters[id]++, |
66 | rnd); |
67 | } |
68 | |