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 #ifndef lint 35 static char sccsid[] = "@(#)rec_seq.c 8.3 (Berkeley) 7/14/94"; 36 #endif /* not lint */ 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include <sys/types.h> 41 42 #include <errno.h> 43 #include <limits.h> 44 #include <stdio.h> 45 #include <string.h> 46 47 #include <db.h> 48 #include "recno.h" 49 50 /* 51 * __REC_SEQ -- Recno sequential scan interface. 52 * 53 * Parameters: 54 * dbp: pointer to access method 55 * key: key for positioning and return value 56 * data: data return value 57 * flags: R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV. 58 * 59 * Returns: 60 * RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key. 61 */ 62 int 63 __rec_seq(dbp, key, data, flags) 64 const DB *dbp; 65 DBT *key, *data; 66 u_int flags; 67 { 68 BTREE *t; 69 EPG *e; 70 recno_t nrec; 71 int status; 72 73 t = dbp->internal; 74 75 /* Toss any page pinned across calls. */ 76 if (t->bt_pinned != NULL) { 77 mpool_put(t->bt_mp, t->bt_pinned, 0); 78 t->bt_pinned = NULL; 79 } 80 81 switch(flags) { 82 case R_CURSOR: 83 if ((nrec = *(recno_t *)key->data) == 0) 84 goto einval; 85 break; 86 case R_NEXT: 87 if (F_ISSET(&t->bt_cursor, CURS_INIT)) { 88 nrec = t->bt_cursor.rcursor + 1; 89 break; 90 } 91 /* FALLTHROUGH */ 92 case R_FIRST: 93 nrec = 1; 94 break; 95 case R_PREV: 96 if (F_ISSET(&t->bt_cursor, CURS_INIT)) { 97 if ((nrec = t->bt_cursor.rcursor - 1) == 0) 98 return (RET_SPECIAL); 99 break; 100 } 101 /* FALLTHROUGH */ 102 case R_LAST: 103 if (!F_ISSET(t, R_EOF | R_INMEM) && 104 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 105 return (RET_ERROR); 106 nrec = t->bt_nrecs; 107 break; 108 default: 109 einval: errno = EINVAL; 110 return (RET_ERROR); 111 } 112 113 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) { 114 if (!F_ISSET(t, R_EOF | R_INMEM) && 115 (status = t->bt_irec(t, nrec)) != RET_SUCCESS) 116 return (status); 117 if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) 118 return (RET_SPECIAL); 119 } 120 121 if ((e = __rec_search(t, nrec - 1, SEARCH)) == NULL) 122 return (RET_ERROR); 123 124 F_SET(&t->bt_cursor, CURS_INIT); 125 t->bt_cursor.rcursor = nrec; 126 127 status = __rec_ret(t, e, nrec, key, data); 128 if (F_ISSET(t, B_DB_LOCK)) 129 mpool_put(t->bt_mp, e->page, 0); 130 else 131 t->bt_pinned = e->page; 132 return (status); 133 } 134