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 * 4. 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 30 #include <sys/cdefs.h> 31 #ifndef lint 32 /* XXX use __SCCSID */ 33 static char sccsid[] __unused = "@(#)rec_seq.c 8.3 (Berkeley) 7/14/94"; 34 #endif /* not lint */ 35 __FBSDID("$FreeBSD$"); 36 37 #include <sys/types.h> 38 39 #include <errno.h> 40 #include <limits.h> 41 #include <stdio.h> 42 #include <string.h> 43 44 #include <db.h> 45 #include "recno.h" 46 47 /* 48 * __REC_SEQ -- Recno sequential scan interface. 49 * 50 * Parameters: 51 * dbp: pointer to access method 52 * key: key for positioning and return value 53 * data: data return value 54 * flags: R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV. 55 * 56 * Returns: 57 * RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key. 58 */ 59 int 60 __rec_seq(const DB *dbp, DBT *key, DBT *data, u_int flags) 61 { 62 BTREE *t; 63 EPG *e; 64 recno_t nrec; 65 int status; 66 67 t = dbp->internal; 68 69 /* Toss any page pinned across calls. */ 70 if (t->bt_pinned != NULL) { 71 mpool_put(t->bt_mp, t->bt_pinned, 0); 72 t->bt_pinned = NULL; 73 } 74 75 switch(flags) { 76 case R_CURSOR: 77 if ((nrec = *(recno_t *)key->data) == 0) 78 goto einval; 79 break; 80 case R_NEXT: 81 if (F_ISSET(&t->bt_cursor, CURS_INIT)) { 82 nrec = t->bt_cursor.rcursor + 1; 83 break; 84 } 85 /* FALLTHROUGH */ 86 case R_FIRST: 87 nrec = 1; 88 break; 89 case R_PREV: 90 if (F_ISSET(&t->bt_cursor, CURS_INIT)) { 91 if ((nrec = t->bt_cursor.rcursor - 1) == 0) 92 return (RET_SPECIAL); 93 break; 94 } 95 /* FALLTHROUGH */ 96 case R_LAST: 97 if (!F_ISSET(t, R_EOF | R_INMEM) && 98 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 99 return (RET_ERROR); 100 nrec = t->bt_nrecs; 101 break; 102 default: 103 einval: errno = EINVAL; 104 return (RET_ERROR); 105 } 106 107 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) { 108 if (!F_ISSET(t, R_EOF | R_INMEM) && 109 (status = t->bt_irec(t, nrec)) != RET_SUCCESS) 110 return (status); 111 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) 112 return (RET_SPECIAL); 113 } 114 115 if ((e = __rec_search(t, nrec - 1, SEARCH)) == NULL) 116 return (RET_ERROR); 117 118 F_SET(&t->bt_cursor, CURS_INIT); 119 t->bt_cursor.rcursor = nrec; 120 121 status = __rec_ret(t, e, nrec, key, data); 122 if (F_ISSET(t, B_DB_LOCK)) 123 mpool_put(t->bt_mp, e->page, 0); 124 else 125 t->bt_pinned = e->page; 126 return (status); 127 } 128