| 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 | |
| 100 | /* |
| 101 | Local Variables: |
| 102 | c-basic-offset:2 |
| 103 | comment-column:40 |
| 104 | fill-column:79 |
| 105 | indent-tabs-mode:nil |
| 106 | End: |
| 107 | */ |