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 */
35static 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 */
61int
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:
105einval:		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