1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1991, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #ifndef lint
34 /* XXX use __SCCSID */
35 static char sccsid[] __unused = "@(#)rec_seq.c 8.3 (Berkeley) 7/14/94";
36 #endif /* not lint */
37 __FBSDID("$FreeBSD$");
38
39 #include <sys/types.h>
40
41 #include <errno.h>
42 #include <limits.h>
43 #include <stdio.h>
44 #include <string.h>
45
46 #include <db.h>
47 #include "recno.h"
48
49 /*
50 * __REC_SEQ -- Recno sequential scan interface.
51 *
52 * Parameters:
53 * dbp: pointer to access method
54 * key: key for positioning and return value
55 * data: data return value
56 * flags: R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV.
57 *
58 * Returns:
59 * RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
60 */
61 int
__rec_seq(const DB * dbp,DBT * key,DBT * data,u_int flags)62 __rec_seq(const DB *dbp, DBT *key, DBT *data, u_int flags)
63 {
64 BTREE *t;
65 EPG *e;
66 recno_t nrec;
67 int status;
68
69 t = dbp->internal;
70
71 /* Toss any page pinned across calls. */
72 if (t->bt_pinned != NULL) {
73 mpool_put(t->bt_mp, t->bt_pinned, 0);
74 t->bt_pinned = NULL;
75 }
76
77 switch(flags) {
78 case R_CURSOR:
79 if ((nrec = *(recno_t *)key->data) == 0)
80 goto einval;
81 break;
82 case R_NEXT:
83 if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
84 nrec = t->bt_cursor.rcursor + 1;
85 break;
86 }
87 /* FALLTHROUGH */
88 case R_FIRST:
89 nrec = 1;
90 break;
91 case R_PREV:
92 if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
93 if ((nrec = t->bt_cursor.rcursor - 1) == 0)
94 return (RET_SPECIAL);
95 break;
96 }
97 /* FALLTHROUGH */
98 case R_LAST:
99 if (!F_ISSET(t, R_EOF | R_INMEM) &&
100 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
101 return (RET_ERROR);
102 nrec = t->bt_nrecs;
103 break;
104 default:
105 einval: errno = EINVAL;
106 return (RET_ERROR);
107 }
108
109 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) {
110 if (!F_ISSET(t, R_EOF | R_INMEM) &&
111 (status = t->bt_irec(t, nrec)) != RET_SUCCESS)
112 return (status);
113 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs)
114 return (RET_SPECIAL);
115 }
116
117 if ((e = __rec_search(t, nrec - 1, SEARCH)) == NULL)
118 return (RET_ERROR);
119
120 F_SET(&t->bt_cursor, CURS_INIT);
121 t->bt_cursor.rcursor = nrec;
122
123 status = __rec_ret(t, e, nrec, key, data);
124 if (F_ISSET(t, B_DB_LOCK))
125 mpool_put(t->bt_mp, e->page, 0);
126 else
127 t->bt_pinned = e->page;
128 return (status);
129 }
130