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