[apple/libc.git] / db / recno / FreeBSD / rec_utils.c

/*-
 * Copyright (c) 1990, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)rec_utils.c 8.6 (Berkeley) 7/16/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/db/recno/rec_utils.c,v 1.6 2009/03/05 00:57:01 delphij Exp $");

#include <sys/param.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <db.h>
#include "recno.h"

/*
 * __rec_ret --
 *      Build return data.
 *
 * Parameters:
 *      t:      tree
 *      e:      key/data pair to be returned
 *   nrec:      record number
 *    key:      user's key structure
 *   data:      user's data structure
 *
 * Returns:
 *      RET_SUCCESS, RET_ERROR.
 */
int
__rec_ret(BTREE *t, EPG *e, recno_t nrec, DBT *key, DBT *data)
{
        RLEAF *rl;
        void *p;

        if (key == NULL)
                goto dataonly;

        /* We have to copy the key, it's not on the page. */
        if (sizeof(recno_t) > t->bt_rkey.size) {
                p = realloc(t->bt_rkey.data, sizeof(recno_t));
                if (p == NULL)
                        return (RET_ERROR);
                t->bt_rkey.data = p;
                t->bt_rkey.size = sizeof(recno_t);
        }
        memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
        key->size = sizeof(recno_t);
        key->data = t->bt_rkey.data;

dataonly:
        if (data == NULL)
                return (RET_SUCCESS);

        /*
         * We must copy big keys/data to make them contigous.  Otherwise,
         * leave the page pinned and don't copy unless the user specified
         * concurrent access.
         */
        rl = GETRLEAF(e->page, e->index);
        if (rl->flags & P_BIGDATA) {
                if (__ovfl_get(t, rl->bytes,
                    &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
                        return (RET_ERROR);
                data->data = t->bt_rdata.data;
        } else if (F_ISSET(t, B_DB_LOCK)) {
                /* Use +1 in case the first record retrieved is 0 length. */
                if (rl->dsize + 1 > t->bt_rdata.size) {
                        p = realloc(t->bt_rdata.data, rl->dsize + 1);
                        if (p == NULL)
                                return (RET_ERROR);
                        t->bt_rdata.data = p;
                        t->bt_rdata.size = rl->dsize + 1;
                }
                memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
                data->size = rl->dsize;
                data->data = t->bt_rdata.data;
        } else {
                data->size = rl->dsize;
                data->data = rl->bytes;
        }
        return (RET_SUCCESS);
}