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