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