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. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 #ifndef lint 36 /* XXX use __SCCSID */ 37 static char sccsid[] __unused = "@(#)rec_seq.c 8.3 (Berkeley) 7/14/94"; 38 #endif /* not lint */ 39 __FBSDID("$FreeBSD$"); 40 41 #include <sys/types.h> 42 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 */ 63 int 64 __rec_seq(dbp, key, data, flags) 65 const DB *dbp; 66 DBT *key, *data; 67 u_int flags; 68 { 69 BTREE *t; 70 EPG *e; 71 recno_t nrec; 72 int status; 73 74 t = dbp->internal; 75 76 /* Toss any page pinned across calls. */ 77 if (t->bt_pinned != NULL) { 78 mpool_put(t->bt_mp, t->bt_pinned, 0); 79 t->bt_pinned = NULL; 80 } 81 82 switch(flags) { 83 case R_CURSOR: 84 if ((nrec = *(recno_t *)key->data) == 0) 85 goto einval; 86 break; 87 case R_NEXT: 88 if (F_ISSET(&t->bt_cursor, CURS_INIT)) { 89 nrec = t->bt_cursor.rcursor + 1; 90 break; 91 } 92 /* FALLTHROUGH */ 93 case R_FIRST: 94 nrec = 1; 95 break; 96 case R_PREV: 97 if (F_ISSET(&t->bt_cursor, CURS_INIT)) { 98 if ((nrec = t->bt_cursor.rcursor - 1) == 0) 99 return (RET_SPECIAL); 100 break; 101 } 102 /* FALLTHROUGH */ 103 case R_LAST: 104 if (!F_ISSET(t, R_EOF | R_INMEM) && 105 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 106 return (RET_ERROR); 107 nrec = t->bt_nrecs; 108 break; 109 default: 110 einval: errno = EINVAL; 111 return (RET_ERROR); 112 } 113 114 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) { 115 if (!F_ISSET(t, R_EOF | R_INMEM) && 116 (status = t->bt_irec(t, nrec)) != RET_SUCCESS) 117 return (status); 118 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) 119 return (RET_SPECIAL); 120 } 121 122 if ((e = __rec_search(t, nrec - 1, SEARCH)) == NULL) 123 return (RET_ERROR); 124 125 F_SET(&t->bt_cursor, CURS_INIT); 126 t->bt_cursor.rcursor = nrec; 127 128 status = __rec_ret(t, e, nrec, key, data); 129 if (F_ISSET(t, B_DB_LOCK)) 130 mpool_put(t->bt_mp, e->page, 0); 131 else 132 t->bt_pinned = e->page; 133 return (status); 134 } 135