ndbm.c

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/*-
 * 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.
 */
 
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)ndbm.c  8.4 (Berkeley) 7/21/94";
#endif /* LIBC_SCCS and not lint */
 
/*
 * This package provides a dbm compatible interface to the new hashing
 * package described in db(3).
 */
 
#include <sys/param.h>
 
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
 
#include <ndbm.h>
#include "hash.h"
 
/*
 * Returns:
 *  *DBM on success
 *   NULL on failure
 */
extern DBM *
dbm_open(file, flags, mode)
    const char *file;
    int flags, mode;
{
    DBM *db;
    HASHINFO info;
    const size_t len = strlen(file) + sizeof (DBM_SUFFIX);
#ifdef __GNUC__
    char path[len];
#else
    char *path = malloc(len);
    if (path == NULL)
        return NULL;
#endif
 
    info.bsize = 4096;
    info.ffactor = 40;
    info.nelem = 1;
    info.cachesize = 0;
    info.hash = NULL;
    info.lorder = 0;
    snprintf(path, len, "%s%s", file, DBM_SUFFIX);
    db = (DBM *)__hash_open(path, flags, mode, &info, 0);
#ifndef __GNUC__
    free(path);
#endif
    return db;
}
 
extern void
dbm_close(db)
    DBM *db;
{
    (void)(db->close)(db);
}
 
/*
 * Returns:
 *  DATUM on success
 *  NULL on failure
 */
extern datum
dbm_fetch(db, key)
    DBM *db;
    datum key;
{
    datum retdata;
    int status;
    DBT dbtkey, dbtretdata;
 
    dbtkey.data = key.dptr;
    dbtkey.size = key.dsize;
    status = (db->get)(db, &dbtkey, &dbtretdata, 0);
    if (status) {
        dbtretdata.data = NULL;
        dbtretdata.size = 0;
    }
    retdata.dptr = dbtretdata.data;
    retdata.dsize = dbtretdata.size;
    return (retdata);
}
 
/*
 * Returns:
 *  DATUM on success
 *  NULL on failure
 */
extern datum
dbm_firstkey(db)
    DBM *db;
{
    int status;
    datum retkey;
    DBT dbtretkey, dbtretdata;
 
    status = (db->seq)(db, &dbtretkey, &dbtretdata, R_FIRST);
    if (status)
        dbtretkey.data = NULL;
    retkey.dptr = dbtretkey.data;
    retkey.dsize = dbtretkey.size;
    return (retkey);
}
 
/*
 * Returns:
 *  DATUM on success
 *  NULL on failure
 */
extern datum
dbm_nextkey(db)
    DBM *db;
{
    int status;
    datum retkey;
    DBT dbtretkey, dbtretdata;
 
    status = (db->seq)(db, &dbtretkey, &dbtretdata, R_NEXT);
    if (status)
        dbtretkey.data = NULL;
    retkey.dptr = dbtretkey.data;
    retkey.dsize = dbtretkey.size;
    return (retkey);
}
/*
 * Returns:
 *   0 on success
 *  <0 failure
 */
extern int
dbm_delete(db, key)
    DBM *db;
    datum key;
{
    int status;
    DBT dbtkey;
 
    dbtkey.data = key.dptr;
    dbtkey.size = key.dsize;
    status = (db->del)(db, &dbtkey, 0);
    if (status)
        return (-1);
    else
        return (0);
}
 
/*
 * Returns:
 *   0 on success
 *  <0 failure
 *   1 if DBM_INSERT and entry exists
 */
extern int
dbm_store(db, key, data, flags)
    DBM *db;
    datum key, data;
    int flags;
{
    DBT dbtkey, dbtdata;
 
    dbtkey.data = key.dptr;
    dbtkey.size = key.dsize;
    dbtdata.data = data.dptr;
    dbtdata.size = data.dsize;
    return ((db->put)(db, &dbtkey, &dbtdata,
        (flags == DBM_INSERT) ? R_NOOVERWRITE : 0));
}
 
extern int
dbm_error(db)
    DBM *db;
{
    HTAB *hp;
 
    hp = (HTAB *)db->internal;
    return (hp->errnum);
}
 
extern int
dbm_clearerr(db)
    DBM *db;
{
    HTAB *hp;
 
    hp = (HTAB *)db->internal;
    hp->errnum = 0;
    return (0);
}
 
extern int
dbm_dirfno(db)
    DBM *db;
{
    return(((HTAB *)db->internal)->fp);
}