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/types.h>
33
34 #include <errno.h>
35 #include <limits.h>
36 #include <stdio.h>
37 #include <string.h>
38
39 #include <db.h>
40 #include "recno.h"
41
42 /*
43 * __REC_SEQ -- Recno sequential scan interface.
44 *
45 * Parameters:
46 * dbp: pointer to access method
47 * key: key for positioning and return value
48 * data: data return value
49 * flags: R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV.
50 *
51 * Returns:
52 * RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
53 */
54 int
__rec_seq(const DB * dbp,DBT * key,DBT * data,u_int flags)55 __rec_seq(const DB *dbp, DBT *key, DBT *data, u_int flags)
56 {
57 BTREE *t;
58 EPG *e;
59 recno_t nrec;
60 int status;
61
62 t = dbp->internal;
63
64 /* Toss any page pinned across calls. */
65 if (t->bt_pinned != NULL) {
66 mpool_put(t->bt_mp, t->bt_pinned, 0);
67 t->bt_pinned = NULL;
68 }
69
70 switch(flags) {
71 case R_CURSOR:
72 if ((nrec = *(recno_t *)key->data) == 0)
73 goto einval;
74 break;
75 case R_NEXT:
76 if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
77 nrec = t->bt_cursor.rcursor + 1;
78 break;
79 }
80 /* FALLTHROUGH */
81 case R_FIRST:
82 nrec = 1;
83 break;
84 case R_PREV:
85 if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
86 if ((nrec = t->bt_cursor.rcursor - 1) == 0)
87 return (RET_SPECIAL);
88 break;
89 }
90 /* FALLTHROUGH */
91 case R_LAST:
92 if (!F_ISSET(t, R_EOF | R_INMEM) &&
93 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
94 return (RET_ERROR);
95 nrec = t->bt_nrecs;
96 break;
97 default:
98 einval: errno = EINVAL;
99 return (RET_ERROR);
100 }
101
102 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) {
103 if (!F_ISSET(t, R_EOF | R_INMEM) &&
104 (status = t->bt_irec(t, nrec)) != RET_SUCCESS)
105 return (status);
106 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs)
107 return (RET_SPECIAL);
108 }
109
110 if ((e = __rec_search(t, nrec - 1, SEARCH)) == NULL)
111 return (RET_ERROR);
112
113 F_SET(&t->bt_cursor, CURS_INIT);
114 t->bt_cursor.rcursor = nrec;
115
116 status = __rec_ret(t, e, nrec, key, data);
117 if (F_ISSET(t, B_DB_LOCK))
118 mpool_put(t->bt_mp, e->page, 0);
119 else
120 t->bt_pinned = e->page;
121 return (status);
122 }
123