shithub: sdbm

ref: 64e312636599ea2c86f21dc1176dca7da77bd74a
dir: /dbm.c/

/*
 * Copyright (c) 1985 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include <u.h>
#include <libc.h>

#include    "dbm.h"

#define    NODB    ((DBM *)0)

static DBM *cur_db = NODB;

static char no_db[] = "dbm: no open database\n";

int
dbminit(char *file)
{
    if (cur_db != NODB)
        dbm_close(cur_db);

    cur_db = dbm_open(file, 2, 0, 0);
    if (cur_db == NODB) {
        cur_db = dbm_open(file, 0, 0, 0);
        if (cur_db == NODB)
            return (-1);
    }
    return (0);
}

long
forder(datum key)
{
    if (cur_db == NODB) {
        print(no_db);
        return (0L);
    }
    return (dbm_forder(cur_db, key));
}

datum
fetch(datum key)
{
    datum item;

    if (cur_db == NODB) {
        print(no_db);
        item.dptr = 0;
        return (item);
    }
    return (dbm_fetch(cur_db, key));
}

delete(datum key)
{
    if (cur_db == NODB) {
        print(no_db);
        return (-1);
    }
    if (dbm_rdonly(cur_db))
        return (-1);
    return (dbm_delete(cur_db, key));
}

store(key, dat)
datum key, dat;
{
    if (cur_db == NODB) {
        print(no_db);
        return (-1);
    }
    if (dbm_rdonly(cur_db))
        return (-1);

    return (dbm_store(cur_db, key, dat, DBM_REPLACE));
}

datum
firstkey()
{
    datum item;

    if (cur_db == NODB) {
        print(no_db);
        item.dptr = 0;
        return (item);
    }
    return (dbm_firstkey(cur_db));
}

datum
nextkey(datum key)
{
    datum item;

    if (cur_db == NODB) {
        print(no_db);
        item.dptr = 0;
        return (item);
    }
    return (dbm_nextkey(cur_db));
}