1*54925bf6Swillf /*-
2*54925bf6Swillf * Copyright (c) 1991, 1993, 1994
3*54925bf6Swillf * The Regents of the University of California. All rights reserved.
4*54925bf6Swillf *
5*54925bf6Swillf * Redistribution and use in source and binary forms, with or without
6*54925bf6Swillf * modification, are permitted provided that the following conditions
7*54925bf6Swillf * are met:
8*54925bf6Swillf * 1. Redistributions of source code must retain the above copyright
9*54925bf6Swillf * notice, this list of conditions and the following disclaimer.
10*54925bf6Swillf * 2. Redistributions in binary form must reproduce the above copyright
11*54925bf6Swillf * notice, this list of conditions and the following disclaimer in the
12*54925bf6Swillf * documentation and/or other materials provided with the distribution.
13*54925bf6Swillf * 3. All advertising materials mentioning features or use of this software
14*54925bf6Swillf * must display the following acknowledgement:
15*54925bf6Swillf * This product includes software developed by the University of
16*54925bf6Swillf * California, Berkeley and its contributors.
17*54925bf6Swillf * 4. Neither the name of the University nor the names of its contributors
18*54925bf6Swillf * may be used to endorse or promote products derived from this software
19*54925bf6Swillf * without specific prior written permission.
20*54925bf6Swillf *
21*54925bf6Swillf * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22*54925bf6Swillf * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23*54925bf6Swillf * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24*54925bf6Swillf * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25*54925bf6Swillf * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26*54925bf6Swillf * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27*54925bf6Swillf * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28*54925bf6Swillf * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29*54925bf6Swillf * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30*54925bf6Swillf * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31*54925bf6Swillf * SUCH DAMAGE.
32*54925bf6Swillf */
33*54925bf6Swillf
34*54925bf6Swillf #if defined(LIBC_SCCS) && !defined(lint)
35*54925bf6Swillf static char sccsid[] = "@(#)rec_seq.c 8.3 (Berkeley) 7/14/94";
36*54925bf6Swillf #endif /* not lint */
37*54925bf6Swillf
38*54925bf6Swillf #include <sys/types.h>
39*54925bf6Swillf
40*54925bf6Swillf #include <errno.h>
41*54925bf6Swillf #include <limits.h>
42*54925bf6Swillf #include <stdio.h>
43*54925bf6Swillf #include <string.h>
44*54925bf6Swillf
45*54925bf6Swillf #include "db-int.h"
46*54925bf6Swillf #include "recno.h"
47*54925bf6Swillf
48*54925bf6Swillf /*
49*54925bf6Swillf * __REC_SEQ -- Recno sequential scan interface.
50*54925bf6Swillf *
51*54925bf6Swillf * Parameters:
52*54925bf6Swillf * dbp: pointer to access method
53*54925bf6Swillf * key: key for positioning and return value
54*54925bf6Swillf * data: data return value
55*54925bf6Swillf * flags: R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV.
56*54925bf6Swillf *
57*54925bf6Swillf * Returns:
58*54925bf6Swillf * RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
59*54925bf6Swillf */
60*54925bf6Swillf int
__rec_seq(dbp,key,data,flags)61*54925bf6Swillf __rec_seq(dbp, key, data, flags)
62*54925bf6Swillf const DB *dbp;
63*54925bf6Swillf DBT *key, *data;
64*54925bf6Swillf u_int flags;
65*54925bf6Swillf {
66*54925bf6Swillf BTREE *t;
67*54925bf6Swillf EPG *e;
68*54925bf6Swillf recno_t nrec;
69*54925bf6Swillf int status;
70*54925bf6Swillf
71*54925bf6Swillf t = dbp->internal;
72*54925bf6Swillf
73*54925bf6Swillf /* Toss any page pinned across calls. */
74*54925bf6Swillf if (t->bt_pinned != NULL) {
75*54925bf6Swillf mpool_put(t->bt_mp, t->bt_pinned, 0);
76*54925bf6Swillf t->bt_pinned = NULL;
77*54925bf6Swillf }
78*54925bf6Swillf
79*54925bf6Swillf switch(flags) {
80*54925bf6Swillf case R_CURSOR:
81*54925bf6Swillf if ((nrec = *(recno_t *)key->data) == 0)
82*54925bf6Swillf goto einval;
83*54925bf6Swillf break;
84*54925bf6Swillf case R_NEXT:
85*54925bf6Swillf if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
86*54925bf6Swillf nrec = t->bt_cursor.rcursor + 1;
87*54925bf6Swillf break;
88*54925bf6Swillf }
89*54925bf6Swillf /* FALLTHROUGH */
90*54925bf6Swillf case R_FIRST:
91*54925bf6Swillf nrec = 1;
92*54925bf6Swillf break;
93*54925bf6Swillf case R_PREV:
94*54925bf6Swillf if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
95*54925bf6Swillf if ((nrec = t->bt_cursor.rcursor - 1) == 0)
96*54925bf6Swillf return (RET_SPECIAL);
97*54925bf6Swillf break;
98*54925bf6Swillf }
99*54925bf6Swillf /* FALLTHROUGH */
100*54925bf6Swillf case R_LAST:
101*54925bf6Swillf if (!F_ISSET(t, R_EOF | R_INMEM) &&
102*54925bf6Swillf t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
103*54925bf6Swillf return (RET_ERROR);
104*54925bf6Swillf nrec = t->bt_nrecs;
105*54925bf6Swillf break;
106*54925bf6Swillf default:
107*54925bf6Swillf einval: errno = EINVAL;
108*54925bf6Swillf return (RET_ERROR);
109*54925bf6Swillf }
110*54925bf6Swillf
111*54925bf6Swillf if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) {
112*54925bf6Swillf if (!F_ISSET(t, R_EOF | R_INMEM) &&
113*54925bf6Swillf (status = t->bt_irec(t, nrec)) != RET_SUCCESS)
114*54925bf6Swillf return (status);
115*54925bf6Swillf if (t->bt_nrecs == 0 || nrec > t->bt_nrecs)
116*54925bf6Swillf return (RET_SPECIAL);
117*54925bf6Swillf }
118*54925bf6Swillf
119*54925bf6Swillf if ((e = __rec_search(t, nrec - 1, SEARCH)) == NULL)
120*54925bf6Swillf return (RET_ERROR);
121*54925bf6Swillf
122*54925bf6Swillf F_SET(&t->bt_cursor, CURS_INIT);
123*54925bf6Swillf t->bt_cursor.rcursor = nrec;
124*54925bf6Swillf
125*54925bf6Swillf status = __rec_ret(t, e, nrec, key, data);
126*54925bf6Swillf if (F_ISSET(t, B_DB_LOCK))
127*54925bf6Swillf mpool_put(t->bt_mp, e->page, 0);
128*54925bf6Swillf else
129*54925bf6Swillf t->bt_pinned = e->page;
130*54925bf6Swillf return (status);
131*54925bf6Swillf }
132