1#pragma ident	"%Z%%M%	%I%	%E% SMI"
2
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. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by the University of
18 *	California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#if defined(LIBC_SCCS) && !defined(lint)
37static char sccsid[] = "@(#)rec_seq.c	8.3 (Berkeley) 7/14/94";
38#endif /* not lint */
39
40#include <sys/types.h>
41
42#include <errno.h>
43#include <limits.h>
44#include <stdio.h>
45#include <string.h>
46
47#include "db-int.h"
48#include "recno.h"
49
50/*
51 * __REC_SEQ -- Recno sequential scan interface.
52 *
53 * Parameters:
54 *	dbp:	pointer to access method
55 *	key:	key for positioning and return value
56 *	data:	data return value
57 *	flags:	R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV.
58 *
59 * Returns:
60 *	RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
61 */
62int
63__rec_seq(dbp, key, data, flags)
64	const DB *dbp;
65	DBT *key, *data;
66	u_int flags;
67{
68	BTREE *t;
69	EPG *e;
70	recno_t nrec;
71	int status;
72
73	t = dbp->internal;
74
75	/* Toss any page pinned across calls. */
76	if (t->bt_pinned != NULL) {
77		mpool_put(t->bt_mp, t->bt_pinned, 0);
78		t->bt_pinned = NULL;
79	}
80
81	switch(flags) {
82	case R_CURSOR:
83		if ((nrec = *(recno_t *)key->data) == 0)
84			goto einval;
85		break;
86	case R_NEXT:
87		if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
88			nrec = t->bt_cursor.rcursor + 1;
89			break;
90		}
91		/* FALLTHROUGH */
92	case R_FIRST:
93		nrec = 1;
94		break;
95	case R_PREV:
96		if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
97			if ((nrec = t->bt_cursor.rcursor - 1) == 0)
98				return (RET_SPECIAL);
99			break;
100		}
101		/* FALLTHROUGH */
102	case R_LAST:
103		if (!F_ISSET(t, R_EOF | R_INMEM) &&
104		    t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
105			return (RET_ERROR);
106		nrec = t->bt_nrecs;
107		break;
108	default:
109einval:		errno = EINVAL;
110		return (RET_ERROR);
111	}
112
113	if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) {
114		if (!F_ISSET(t, R_EOF | R_INMEM) &&
115		    (status = t->bt_irec(t, nrec)) != RET_SUCCESS)
116			return (status);
117		if (t->bt_nrecs == 0 || nrec > t->bt_nrecs)
118			return (RET_SPECIAL);
119	}
120
121	if ((e = __rec_search(t, nrec - 1, SEARCH)) == NULL)
122		return (RET_ERROR);
123
124	F_SET(&t->bt_cursor, CURS_INIT);
125	t->bt_cursor.rcursor = nrec;
126
127	status = __rec_ret(t, e, nrec, key, data);
128	if (F_ISSET(t, B_DB_LOCK))
129		mpool_put(t->bt_mp, e->page, 0);
130	else
131		t->bt_pinned = e->page;
132	return (status);
133}
134