1 /* $NetBSD: rec_seq.c,v 1.14 2008/09/11 12:58:00 joerg Exp $ */
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. 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 #if HAVE_NBTOOL_CONFIG_H
33 #include "nbtool_config.h"
34 #endif
35
36 #include <sys/cdefs.h>
37 __RCSID("$NetBSD: rec_seq.c,v 1.14 2008/09/11 12:58:00 joerg Exp $");
38
39 #include "namespace.h"
40 #include <sys/types.h>
41
42 #include <assert.h>
43 #include <errno.h>
44 #include <limits.h>
45 #include <stdio.h>
46 #include <string.h>
47
48 #include <db.h>
49 #include "recno.h"
50
51 /*
52 * __REC_SEQ -- Recno sequential scan interface.
53 *
54 * Parameters:
55 * dbp: pointer to access method
56 * key: key for positioning and return value
57 * data: data return value
58 * flags: R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV.
59 *
60 * Returns:
61 * RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
62 */
63 int
__rec_seq(const DB * dbp,DBT * key,DBT * data,u_int flags)64 __rec_seq(const DB *dbp, DBT *key, DBT *data, u_int flags)
65 {
66 BTREE *t;
67 EPG *e;
68 recno_t nrec;
69 int status;
70
71 t = dbp->internal;
72
73 /* Toss any page pinned across calls. */
74 if (t->bt_pinned != NULL) {
75 mpool_put(t->bt_mp, t->bt_pinned, 0);
76 t->bt_pinned = NULL;
77 }
78
79 switch(flags) {
80 case R_CURSOR:
81 if ((nrec = *(recno_t *)key->data) == 0)
82 goto einval;
83 break;
84 case R_NEXT:
85 if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
86 nrec = t->bt_cursor.rcursor + 1;
87 break;
88 }
89 /* FALLTHROUGH */
90 case R_FIRST:
91 nrec = 1;
92 break;
93 case R_PREV:
94 if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
95 if ((nrec = t->bt_cursor.rcursor - 1) == 0)
96 return (RET_SPECIAL);
97 break;
98 }
99 /* FALLTHROUGH */
100 case R_LAST:
101 if (!F_ISSET(t, R_EOF | R_INMEM) &&
102 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
103 return (RET_ERROR);
104 nrec = t->bt_nrecs;
105 break;
106 default:
107 einval: errno = EINVAL;
108 return (RET_ERROR);
109 }
110
111 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) {
112 if (!F_ISSET(t, R_EOF | R_INMEM) &&
113 (status = t->bt_irec(t, nrec)) != RET_SUCCESS)
114 return (status);
115 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs)
116 return (RET_SPECIAL);
117 }
118
119 if ((e = __rec_search(t, nrec - 1, SEARCH)) == NULL)
120 return (RET_ERROR);
121
122 F_SET(&t->bt_cursor, CURS_INIT);
123 t->bt_cursor.rcursor = nrec;
124
125 status = __rec_ret(t, e, nrec, key, data);
126 if (F_ISSET(t, B_DB_LOCK))
127 mpool_put(t->bt_mp, e->page, 0);
128 else
129 t->bt_pinned = e->page;
130 return (status);
131 }
132