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Annotation of src/lib/libc/db/recno/rec_seq.c, Revision 1.14

1.14    ! joerg       1: /*     $NetBSD: rec_seq.c,v 1.13 2008/09/10 17:52:36 joerg Exp $       */
1.6       cgd         2:
1.1       cgd         3: /*-
1.7       cgd         4:  * Copyright (c) 1991, 1993, 1994
1.1       cgd         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.
1.11      agc        15:  * 3. Neither the name of the University nor the names of its contributors
1.1       cgd        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:
1.14    ! joerg      32: #if HAVE_NBTOOL_CONFIG_H
        !            33: #include "nbtool_config.h"
        !            34: #endif
        !            35:
1.8       christos   36: #include <sys/cdefs.h>
1.14    ! joerg      37: __RCSID("$NetBSD: rec_seq.c,v 1.13 2008/09/10 17:52:36 joerg Exp $");
1.1       cgd        38:
1.9       jtc        39: #include "namespace.h"
1.1       cgd        40: #include <sys/types.h>
                     41:
1.12      christos   42: #include <assert.h>
1.1       cgd        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
1.12      christos   64: __rec_seq(const DB *dbp, DBT *key, DBT *data, u_int flags)
1.1       cgd        65: {
                     66:        BTREE *t;
                     67:        EPG *e;
                     68:        recno_t nrec;
                     69:        int status;
                     70:
                     71:        t = dbp->internal;
1.4       cgd        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:
1.1       cgd        79:        switch(flags) {
                     80:        case R_CURSOR:
                     81:                if ((nrec = *(recno_t *)key->data) == 0)
                     82:                        goto einval;
                     83:                break;
                     84:        case R_NEXT:
1.7       cgd        85:                if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
                     86:                        nrec = t->bt_cursor.rcursor + 1;
1.1       cgd        87:                        break;
                     88:                }
                     89:                /* FALLTHROUGH */
                     90:        case R_FIRST:
                     91:                nrec = 1;
                     92:                break;
                     93:        case R_PREV:
1.7       cgd        94:                if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
                     95:                        if ((nrec = t->bt_cursor.rcursor - 1) == 0)
1.1       cgd        96:                                return (RET_SPECIAL);
                     97:                        break;
                     98:                }
                     99:                /* FALLTHROUGH */
                    100:        case R_LAST:
1.7       cgd       101:                if (!F_ISSET(t, R_EOF | R_INMEM) &&
1.1       cgd       102:                    t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
                    103:                        return (RET_ERROR);
                    104:                nrec = t->bt_nrecs;
                    105:                break;
                    106:        default:
                    107: einval:                errno = EINVAL;
                    108:                return (RET_ERROR);
                    109:        }
                    110:
                    111:        if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) {
1.7       cgd       112:                if (!F_ISSET(t, R_EOF | R_INMEM) &&
1.1       cgd       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:
1.7       cgd       122:        F_SET(&t->bt_cursor, CURS_INIT);
                    123:        t->bt_cursor.rcursor = nrec;
1.1       cgd       124:
                    125:        status = __rec_ret(t, e, nrec, key, data);
1.7       cgd       126:        if (F_ISSET(t, B_DB_LOCK))
1.4       cgd       127:                mpool_put(t->bt_mp, e->page, 0);
                    128:        else
                    129:                t->bt_pinned = e->page;
1.1       cgd       130:        return (status);
                    131: }