1 /* $NetBSD: rec_seq.c,v 1.10 2000/09/13 22:32:27 msaitoh 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)rec_seq.c 8.3 (Berkeley) 7/14/94"; 40 #else 41 __RCSID("$NetBSD: rec_seq.c,v 1.10 2000/09/13 22:32:27 msaitoh Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include "namespace.h" 46 #include <sys/types.h> 47 48 #include <errno.h> 49 #include <limits.h> 50 #include <stdio.h> 51 #include <string.h> 52 53 #include <db.h> 54 #include "recno.h" 55 56 /* 57 * __REC_SEQ -- Recno sequential scan interface. 58 * 59 * Parameters: 60 * dbp: pointer to access method 61 * key: key for positioning and return value 62 * data: data return value 63 * flags: R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV. 64 * 65 * Returns: 66 * RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key. 67 */ 68 int 69 __rec_seq(dbp, key, data, flags) 70 const DB *dbp; 71 DBT *key, *data; 72 u_int flags; 73 { 74 BTREE *t; 75 EPG *e; 76 recno_t nrec; 77 int status; 78 79 t = dbp->internal; 80 81 /* Toss any page pinned across calls. */ 82 if (t->bt_pinned != NULL) { 83 mpool_put(t->bt_mp, t->bt_pinned, 0); 84 t->bt_pinned = NULL; 85 } 86 87 switch(flags) { 88 case R_CURSOR: 89 if ((nrec = *(recno_t *)key->data) == 0) 90 goto einval; 91 break; 92 case R_NEXT: 93 if (F_ISSET(&t->bt_cursor, CURS_INIT)) { 94 nrec = t->bt_cursor.rcursor + 1; 95 break; 96 } 97 /* FALLTHROUGH */ 98 case R_FIRST: 99 nrec = 1; 100 break; 101 case R_PREV: 102 if (F_ISSET(&t->bt_cursor, CURS_INIT)) { 103 if ((nrec = t->bt_cursor.rcursor - 1) == 0) 104 return (RET_SPECIAL); 105 break; 106 } 107 /* FALLTHROUGH */ 108 case R_LAST: 109 if (!F_ISSET(t, R_EOF | R_INMEM) && 110 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 111 return (RET_ERROR); 112 nrec = t->bt_nrecs; 113 break; 114 default: 115 einval: errno = EINVAL; 116 return (RET_ERROR); 117 } 118 119 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) { 120 if (!F_ISSET(t, R_EOF | R_INMEM) && 121 (status = t->bt_irec(t, nrec)) != RET_SUCCESS) 122 return (status); 123 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) 124 return (RET_SPECIAL); 125 } 126 127 if ((e = __rec_search(t, nrec - 1, SEARCH)) == NULL) 128 return (RET_ERROR); 129 130 F_SET(&t->bt_cursor, CURS_INIT); 131 t->bt_cursor.rcursor = nrec; 132 133 status = __rec_ret(t, e, nrec, key, data); 134 if (F_ISSET(t, B_DB_LOCK)) 135 mpool_put(t->bt_mp, e->page, 0); 136 else 137 t->bt_pinned = e->page; 138 return (status); 139 } 140