db/hsearch/hsearch.c

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996, 1997, 1998
 *  Sleepycat Software.  All rights reserved.
 */
/*
 * Copyright (c) 1990, 1993
 *  Margo Seltzer.  All rights reserved.
 */
/*
 * Copyright (c) 1990, 1993
 *  The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Margo Seltzer.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *  This product includes software developed by the University of
 *  California, Berkeley and its contributors.
 * 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.
 */

#include "config.h"

#ifndef lint
static const char sccsid[] = "@(#)hsearch.c 10.9 (Sleepycat) 4/18/98";
#endif /* not lint */

#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>

#include <errno.h>
#include <string.h>
#endif

#define DB_DBM_HSEARCH  1
#include "db_int.h"

static DB   *dbp;
static ENTRY     retval;

int
__db_hcreate(nel)
    size_t nel;
{
    DB_INFO dbinfo;

    memset(&dbinfo, 0, sizeof(dbinfo));
    dbinfo.db_pagesize = 512;
    dbinfo.h_ffactor = 16;
    dbinfo.h_nelem = (u_int32_t)nel;    /* XXX: Possible overflow. */

    errno = db_open(NULL,
        DB_HASH, DB_CREATE, __db_omode("rw----"), NULL, &dbinfo, &dbp);
    return (errno == 0 ? 1 : 0);
}

ENTRY *
__db_hsearch(item, action)
    ENTRY item;
    ACTION action;
{
    DBT key, val;

    if (dbp == NULL) {
        errno = EINVAL;
        return (NULL);
    }
    memset(&key, 0, sizeof(key));
    memset(&val, 0, sizeof(val));
    key.data = item.key;
    key.size = strlen(item.key) + 1;

    switch (action) {
    case ENTER:
        val.data = item.data;
        val.size = strlen(item.data) + 1;

        /*
         * Try and add the key to the database.  If we fail because
         * the key already exists, return the existing key.
         */
        if ((errno =
            dbp->put(dbp, NULL, &key, &val, DB_NOOVERWRITE)) == 0)
            break;
        if (errno != DB_KEYEXIST)
            return (NULL);
        if ((errno = dbp->get(dbp, NULL, &key, &val, 0)) == 0)
            break;

        if (errno == DB_NOTFOUND)   /* XXX: can't happen. */
            errno = EINVAL;
        break;
    case FIND:
        if ((errno = dbp->get(dbp, NULL, &key, &val, 0)) != 0) {
            if (errno == DB_NOTFOUND)
                errno = 0;
            return (NULL);
        }
        item.data = (char *)val.data;
        break;
    default:
        errno = EINVAL;
        return (NULL);
    }
    retval.key = item.key;
    retval.data = item.data;
    return (&retval);
}

void
__db_hdestroy()
{
    if (dbp != NULL) {
        (void)dbp->close(dbp, 0);
        dbp = NULL;
    }
}