1 /*- 2 * Copyright (c) 1991, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)rec_seq.c 8.3 (Berkeley) 7/14/94 30 * $FreeBSD: head/lib/libc/db/recno/rec_seq.c 189327 2009-03-04 00:58:04Z delphij $ 31 */ 32 33 #include <sys/types.h> 34 35 #include <errno.h> 36 #include <limits.h> 37 #include <stdio.h> 38 #include <string.h> 39 40 #include <db.h> 41 #include "recno.h" 42 43 /* 44 * __REC_SEQ -- Recno sequential scan interface. 45 * 46 * Parameters: 47 * dbp: pointer to access method 48 * key: key for positioning and return value 49 * data: data return value 50 * flags: R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV. 51 * 52 * Returns: 53 * RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key. 54 */ 55 int 56 __rec_seq(const DB *dbp, DBT *key, DBT *data, unsigned int flags) 57 { 58 BTREE *t; 59 EPG *e; 60 recno_t nrec; 61 int status; 62 63 t = dbp->internal; 64 65 /* Toss any page pinned across calls. */ 66 if (t->bt_pinned != NULL) { 67 mpool_put(t->bt_mp, t->bt_pinned, 0); 68 t->bt_pinned = NULL; 69 } 70 71 switch(flags) { 72 case R_CURSOR: 73 if ((nrec = *(recno_t *)key->data) == 0) 74 goto einval; 75 break; 76 case R_NEXT: 77 if (F_ISSET(&t->bt_cursor, CURS_INIT)) { 78 nrec = t->bt_cursor.rcursor + 1; 79 break; 80 } 81 /* FALLTHROUGH */ 82 case R_FIRST: 83 nrec = 1; 84 break; 85 case R_PREV: 86 if (F_ISSET(&t->bt_cursor, CURS_INIT)) { 87 if ((nrec = t->bt_cursor.rcursor - 1) == 0) 88 return (RET_SPECIAL); 89 break; 90 } 91 /* FALLTHROUGH */ 92 case R_LAST: 93 if (!F_ISSET(t, R_EOF | R_INMEM) && 94 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 95 return (RET_ERROR); 96 nrec = t->bt_nrecs; 97 break; 98 default: 99 einval: errno = EINVAL; 100 return (RET_ERROR); 101 } 102 103 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) { 104 if (!F_ISSET(t, R_EOF | R_INMEM) && 105 (status = t->bt_irec(t, nrec)) != RET_SUCCESS) 106 return (status); 107 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) 108 return (RET_SPECIAL); 109 } 110 111 if ((e = __rec_search(t, nrec - 1, SEARCH)) == NULL) 112 return (RET_ERROR); 113 114 F_SET(&t->bt_cursor, CURS_INIT); 115 t->bt_cursor.rcursor = nrec; 116 117 status = __rec_ret(t, e, nrec, key, data); 118 if (F_ISSET(t, B_DB_LOCK)) 119 mpool_put(t->bt_mp, e->page, 0); 120 else 121 t->bt_pinned = e->page; 122 return (status); 123 } 124