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1 | /* |
2 | * This file is part of DisOrder |
3 | * Copyright (C) 2006 Richard Kettlewell |
4 | * |
5 | * This program is free software; you can redistribute it and/or modify |
6 | * it under the terms of the GNU General Public License as published by |
7 | * the Free Software Foundation; either version 2 of the License, or |
8 | * (at your option) any later version. |
9 | * |
10 | * This program is distributed in the hope that it will be useful, but |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | * General Public License for more details. |
14 | * |
15 | * You should have received a copy of the GNU General Public License |
16 | * along with this program; if not, write to the Free Software |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 |
18 | * USA |
19 | */ |
20 | |
21 | #include <config.h> |
22 | #include "types.h" |
23 | |
24 | #include <time.h> |
25 | |
26 | #include "hash.h" |
27 | #include "mem.h" |
28 | #include "log.h" |
29 | #include "cache.h" |
30 | |
31 | static hash *h; |
32 | |
33 | struct cache_entry { |
34 | const struct cache_type *type; |
35 | const void *value; |
36 | time_t birth; |
37 | }; |
38 | |
39 | static int expired(const struct cache_entry *c, time_t now) { |
40 | return now - c->birth > c->type->lifetime; |
41 | } |
42 | |
43 | void cache_put(const struct cache_type *type, |
44 | const char *key, const void *value) { |
45 | struct cache_entry *c; |
46 | |
47 | if(!h) |
48 | h = hash_new(sizeof (struct cache_entry)); |
49 | c = xmalloc(sizeof *c); |
50 | c->type = type; |
51 | c->value = value; |
52 | time(&c->birth); |
53 | hash_add(h, key, c, HASH_INSERT_OR_REPLACE); |
54 | } |
55 | |
56 | const void *cache_get(const struct cache_type *type, const char *key) { |
57 | const struct cache_entry *c; |
58 | |
59 | if(h |
60 | && (c = hash_find(h, key)) |
61 | && c->type == type |
62 | && !expired(c, time(0))) |
63 | return c->value; |
64 | else |
65 | return 0; |
66 | } |
67 | |
68 | static int expiry_callback(const char *key, void *value, void *u) { |
69 | const struct cache_entry *c = value; |
70 | const time_t *now = u; |
71 | |
72 | if(expired(c, *now)) |
73 | hash_remove(h, key); |
74 | return 0; |
75 | } |
76 | |
77 | void cache_expire(void) { |
78 | time_t now; |
79 | |
80 | if(h) { |
81 | time(&now); |
82 | hash_foreach(h, expiry_callback, &now); |
83 | } |
84 | } |
85 | |
86 | static int clean_callback(const char *key, void *value, void *u) { |
87 | const struct cache_entry *c = value; |
88 | const struct cache_type *type = u; |
89 | |
90 | if(!type || c->type == type) |
91 | hash_remove(h, key); |
92 | return 0; |
93 | } |
94 | |
95 | void cache_clean(const struct cache_type *type) { |
96 | if(h) |
97 | hash_foreach(h, clean_callback, (void *)type); |
98 | } |
99 | |
0b7c8909 |
100 | size_t cache_count(void) { |
101 | return h ? hash_count(h) : 0; |
102 | } |
103 | |
460b9539 |
104 | /* |
105 | Local Variables: |
106 | c-basic-offset:2 |
107 | comment-column:40 |
108 | fill-column:79 |
109 | indent-tabs-mode:nil |
110 | End: |
111 | */ |