1 /* dcache.c: BetaFTPD directory listing cache
2 Copyright (C) 2000 Steinar H. Gunderson
4 This program is is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License, version 2 of the
6 License as published by the Free Software Foundation.
8 This program is distributed in the hope that it will be useful,
9 but WITHOUT ANY WARRANTY; without even the implied warranty of
10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 GNU General Public License for more details.
13 You should have received a copy of the GNU General Public License
14 along with this program; if not, write to the Free Software
15 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
42 extern struct dcache *first_dcache;
46 * Allocates a new directory cache entry (type `struct dcache'),
47 * and adds it to the linked list.
49 struct dcache *alloc_new_dcache()
51 struct dcache *d = (struct dcache *)(malloc(sizeof(struct dcache)));
53 if (d == NULL) return d;
57 strcpy(d->dir_name, "");
60 add_to_linked_list((struct list_element *)first_dcache,
61 (struct list_element *)d);
68 * Destroy a directory listing cache entry, remove it from the
69 * linked list, and clean up after it.
71 * If you free a cache entry that is in use (use_count > 0),
72 * BetaFTPD will most likely crash (later). The thing you're supposed
73 * to do when you're done with a dcache entry, is to decrement
74 * its use_count, and let the timeout functions do the destroying
75 * when it's time to do so.
77 void destroy_dcache(struct dcache * const d)
79 if (d == NULL) return;
81 if (d->dir_data != NULL) free(d->dir_data);
82 remove_from_linked_list((struct list_element *)d);
87 * Time out expired directory listing cache entries.
88 * Uses much of the same code as time_out_sockets().
90 void time_out_dcache()
92 struct dcache *d = NULL, *next = first_dcache->next_dcache;
93 time_t now = time(NULL);
95 /* run through the linked list */
96 while (next != NULL) {
98 next = d->next_dcache;
100 if (d->use_count == 0 && (now - d->last_used > 900)) {
108 * Add a new entry in the dcache, using information from
109 * the given file transfer object, and the current directory
112 void populate_dcache(struct ftran * const f, const char * const cwd,
113 const char * const pattern, const struct list_options * const lo)
116 struct dcache *d = alloc_new_dcache();
117 if (d != NULL && stat(cwd, &buf) > -1) {
120 d->dir_data = f->file_data;
121 d->dir_size = f->size;
122 d->generated = buf.st_mtime;
124 strcpy(d->dir_name, cwd);
125 strncpy(d->pattern, pattern, 255);
133 * Check if there is an existing dcache object matching our
136 struct dcache *find_dcache(const char * const cwd, const char * const pattern,
137 const struct list_options * const lo)
139 struct dcache *d = NULL, *next = first_dcache->next_dcache;
142 if (stat(cwd, &buf) > -1) {
143 /* run through the linked list */
144 while (next != NULL) {
146 next = d->next_dcache;
148 if (buf.st_mtime <= d->generated &&
149 strcmp(d->dir_name, cwd) == 0 &&
150 strcmp(d->pattern, pattern) == 0 &&
151 memcmp(&(d->lo), lo, sizeof(struct list_options)) == 0) {
158 #endif /* WANT_DCACHE */