1/* $NetBSD: rec_seq.c,v 1.13 2008/09/10 17:52:36 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 1.13 2008/09/10 17:52:36 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 */ 63int 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: 107einval: 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