1/* $OpenBSD: hashed_db.c,v 1.2 2023/10/17 09:52:09 nicm Exp $ */
2
3/****************************************************************************
4 * Copyright 2019,2020 Thomas E. Dickey                                     *
5 * Copyright 2006-2011,2013 Free Software Foundation, Inc.                  *
6 *                                                                          *
7 * Permission is hereby granted, free of charge, to any person obtaining a  *
8 * copy of this software and associated documentation files (the            *
9 * "Software"), to deal in the Software without restriction, including      *
10 * without limitation the rights to use, copy, modify, merge, publish,      *
11 * distribute, distribute with modifications, sublicense, and/or sell       *
12 * copies of the Software, and to permit persons to whom the Software is    *
13 * furnished to do so, subject to the following conditions:                 *
14 *                                                                          *
15 * The above copyright notice and this permission notice shall be included  *
16 * in all copies or substantial portions of the Software.                   *
17 *                                                                          *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
21 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
24 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
25 *                                                                          *
26 * Except as contained in this notice, the name(s) of the above copyright   *
27 * holders shall not be used in advertising or otherwise to promote the     *
28 * sale, use or other dealings in this Software without prior written       *
29 * authorization.                                                           *
30 ****************************************************************************/
31
32/****************************************************************************
33 *  Author: Thomas E. Dickey                        2006-on                 *
34 ****************************************************************************/
35
36#include <curses.priv.h>
37#include <tic.h>
38#include <hashed_db.h>
39
40#if USE_HASHED_DB
41
42MODULE_ID("$Id: hashed_db.c,v 1.2 2023/10/17 09:52:09 nicm Exp $")
43
44#if HASHED_DB_API >= 2
45static DBC *cursor;
46#endif
47
48typedef struct _myconn {
49    struct _myconn *next;
50    DB *db;
51    char *path;
52    bool modify;
53} MYCONN;
54
55static MYCONN *connections;
56
57static void
58cleanup(void)
59{
60    while (connections != 0) {
61	_nc_db_close(connections->db);
62    }
63}
64
65static DB *
66find_connection(const char *path, bool modify)
67{
68    DB *result = 0;
69    MYCONN *p;
70
71    for (p = connections; p != 0; p = p->next) {
72	if (!strcmp(p->path, path) && p->modify == modify) {
73	    result = p->db;
74	    break;
75	}
76    }
77
78    return result;
79}
80
81static void
82drop_connection(DB * db)
83{
84    MYCONN *p, *q;
85
86    for (p = connections, q = 0; p != 0; q = p, p = p->next) {
87	if (p->db == db) {
88	    if (q != 0)
89		q->next = p->next;
90	    else
91		connections = p->next;
92	    free(p->path);
93	    free(p);
94	    break;
95	}
96    }
97}
98
99static void
100make_connection(DB * db, const char *path, bool modify)
101{
102    MYCONN *p = typeCalloc(MYCONN, 1);
103
104    if (p != 0) {
105	p->db = db;
106	p->path = strdup(path);
107	p->modify = modify;
108	if (p->path != 0) {
109	    p->next = connections;
110	    connections = p;
111	} else {
112	    free(p);
113	}
114    }
115}
116
117/*
118 * Open the database.
119 */
120NCURSES_EXPORT(DB *)
121_nc_db_open(const char *path, bool modify)
122{
123    DB *result = 0;
124    int code;
125
126    if (connections == 0)
127	atexit(cleanup);
128
129    if ((result = find_connection(path, modify)) == 0) {
130
131#if HASHED_DB_API >= 4
132	db_create(&result, NULL, 0);
133	if ((code = result->open(result,
134				 NULL,
135				 path,
136				 NULL,
137				 DB_HASH,
138				 modify ? DB_CREATE : DB_RDONLY,
139				 0644)) != 0) {
140	    result = 0;
141	}
142#elif HASHED_DB_API >= 3
143	db_create(&result, NULL, 0);
144	if ((code = result->open(result,
145				 path,
146				 NULL,
147				 DB_HASH,
148				 modify ? DB_CREATE : DB_RDONLY,
149				 0644)) != 0) {
150	    result = 0;
151	}
152#elif HASHED_DB_API >= 2
153	if ((code = db_open(path,
154			    DB_HASH,
155			    modify ? DB_CREATE : DB_RDONLY,
156			    0644,
157			    (DB_ENV *) 0,
158			    (DB_INFO *) 0,
159			    &result)) != 0) {
160	    result = 0;
161	}
162#else
163	if ((result = dbopen(path,
164			     modify ? (O_CREAT | O_RDWR) : O_RDONLY,
165			     0644,
166			     DB_HASH,
167			     NULL)) == 0) {
168	    code = errno;
169	}
170#endif
171	if (result != 0) {
172	    make_connection(result, path, modify);
173	    T(("opened %s", path));
174	} else {
175	    T(("cannot open %s: %s", path, strerror(code)));
176	}
177    }
178    return result;
179}
180
181/*
182 * Close the database.  Do not attempt to use the 'db' handle after this call.
183 */
184NCURSES_EXPORT(int)
185_nc_db_close(DB * db)
186{
187    int result;
188
189    drop_connection(db);
190#if HASHED_DB_API >= 2
191    result = db->close(db, 0);
192#else
193    result = db->close(db);
194#endif
195    return result;
196}
197
198/*
199 * Write a record to the database.
200 *
201 * Returns 0 on success.
202 *
203 * FIXME:  the FreeBSD cap_mkdb program assumes the database could have
204 * duplicates.  There appears to be no good reason for that (review/fix).
205 */
206NCURSES_EXPORT(int)
207_nc_db_put(DB * db, DBT * key, DBT * data)
208{
209    int result;
210#if HASHED_DB_API >= 2
211    /* remove any pre-existing value, since we do not want duplicates */
212    (void) db->del(db, NULL, key, 0);
213    result = db->put(db, NULL, key, data, DB_NOOVERWRITE);
214#else
215    result = db->put(db, key, data, R_NOOVERWRITE);
216#endif
217    return result;
218}
219
220/*
221 * Read a record from the database.
222 *
223 * Returns 0 on success.
224 */
225NCURSES_EXPORT(int)
226_nc_db_get(DB * db, DBT * key, DBT * data)
227{
228    int result;
229
230    memset(data, 0, sizeof(*data));
231#if HASHED_DB_API >= 2
232    result = db->get(db, NULL, key, data, 0);
233#else
234    result = db->get(db, key, data, 0);
235#endif
236    return result;
237}
238
239/*
240 * Read the first record from the database, ignoring order.
241 *
242 * Returns 0 on success.
243 */
244NCURSES_EXPORT(int)
245_nc_db_first(DB * db, DBT * key, DBT * data)
246{
247    int result;
248
249    memset(key, 0, sizeof(*key));
250    memset(data, 0, sizeof(*data));
251#if HASHED_DB_API >= 2
252    if ((result = db->cursor(db, NULL, &cursor, 0)) == 0) {
253	result = cursor->c_get(cursor, key, data, DB_FIRST);
254    }
255#else
256    result = db->seq(db, key, data, 0);
257#endif
258    return result;
259}
260
261/*
262 * Read the next record from the database, ignoring order.
263 *
264 * Returns 0 on success.
265 */
266NCURSES_EXPORT(int)
267_nc_db_next(DB * db, DBT * key, DBT * data)
268{
269    int result;
270
271#if HASHED_DB_API >= 2
272    (void) db;
273    if (cursor != 0) {
274	result = cursor->c_get(cursor, key, data, DB_NEXT);
275    } else {
276	result = -1;
277    }
278#else
279    result = db->seq(db, key, data, R_NEXT);
280#endif
281    return result;
282}
283
284/*
285 * Check if a record is a terminfo index record.  Index records are those that
286 * contain only an alias pointing to a list of aliases.
287 */
288NCURSES_EXPORT(bool)
289_nc_db_have_index(DBT * key, DBT * data, char **buffer, int *size)
290{
291    bool result = FALSE;
292    int used = (int) data->size - 1;
293    char *have = (char *) data->data;
294
295    (void) key;
296    if (*have++ == 2) {
297	result = TRUE;
298    }
299    /*
300     * Update params in any case for consistency with _nc_db_have_data().
301     */
302    *buffer = have;
303    *size = used;
304    return result;
305}
306
307/*
308 * Check if a record is the terminfo data record.  Ignore index records, e.g.,
309 * those that contain only an alias pointing to a list of aliases.
310 */
311NCURSES_EXPORT(bool)
312_nc_db_have_data(DBT * key, DBT * data, char **buffer, int *size)
313{
314    bool result = FALSE;
315    int used = (int) data->size - 1;
316    char *have = (char *) data->data;
317
318    if (*have++ == 0) {
319	if (data->size > key->size
320	    && IS_TIC_MAGIC(have)) {
321	    result = TRUE;
322	}
323    }
324    /*
325     * Update params in any case to make it simple to follow a index record
326     * to the data record.
327     */
328    *buffer = have;
329    *size = used;
330    return result;
331}
332
333#else
334
335extern
336NCURSES_EXPORT(void)
337_nc_hashed_db(void);
338
339NCURSES_EXPORT(void)
340_nc_hashed_db(void)
341{
342}
343
344#endif /* USE_HASHED_DB */
345