/*-
 * Copyright (c) 2015 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Christos Zoulas.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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 <sys/cdefs.h>
__RCSID("$NetBSD: h_lfsr.c,v 1.2 2017/06/24 10:25:23 gson Exp $");

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <err.h>
#include <string.h>
#include <unistd.h>
#include <db.h>

#define MAXKEY 1000
#ifdef DEBUG
#define DPRINTF(...)    printf(__VA_ARGS__)
#else
#define DPRINTF(...)
#endif

static uint16_t
next(uint16_t *cur)
{
        uint16_t lsb = *cur & 1;
        *cur >>= 1;
        *cur ^= (-lsb) & 0xB400u;
        return *cur;
}

int
main(int argc, char *argv[])
{
        char buf[65536];
        char kb[256];
        DBT key, val;
        DB *db;
        HASHINFO hi;
        uint8_t c;
        uint16_t len;
        uint32_t pagesize = atoi(argv[1]);

        memset(&hi, 0, sizeof(hi));
        memset(buf, 'a', sizeof(buf));
        hi.bsize = pagesize;
        hi.nelem = 65536;
        hi.ffactor = 128;

        key.data = kb;
        val.data = buf;

        db = dbopen(NULL, O_CREAT|O_TRUNC|O_RDWR, 0, DB_HASH, &hi);
        if (db == NULL)
                err(EXIT_FAILURE, "dbopen");

        len = 0xaec1;
        for (size_t i = 0; i < MAXKEY; i++) {
                key.size = (len & 0xff) + 1;
                c = len >> 8;
                memset(kb, c, key.size);
                val.size = (next(&len) & 0xff) + 1;
                switch ((*db->put)(db, &key, &val, R_NOOVERWRITE)) {
                case 0:
                        DPRINTF("put %zu %zu %#x\n",
                            key.size, val.size, c);
                        break;
                case -1:
                        err(EXIT_FAILURE, "put error %zu %zu %#x",
                            key.size, val.size, c);
                case 1:
                        errx(EXIT_FAILURE, "put overwrite %zu %zu %#x",
                            key.size, val.size, c);
                default:
                        abort();
                }
        }

        len = 0xaec1;
        for (size_t i = 0; i < MAXKEY; i++) {
                key.size = (len & 0xff) + 1;
                c = len >> 8;
                memset(kb, c, key.size);
                next(&len);
                switch ((*db->get)(db, &key, &val, 0)) {
                case 0:
                        DPRINTF("get %zu %zu %#x\n",
                            key.size, val.size, c);
                        break;
                case -1:
                        err(EXIT_FAILURE, "get %zu %zu %#x",
                            key.size, val.size, c);
                case 1:
                        errx(EXIT_FAILURE, "get not found %zu %zu %#x",
                            key.size, val.size, c);
                default:
                        abort();
                }
                if (memcmp(key.data, kb, key.size) != 0)
                        errx(EXIT_FAILURE, "get badkey %zu %zu %#x",
                            key.size, val.size, c);
                if (val.size != (len & 0xff) + 1U)
                        errx(EXIT_FAILURE, "get badvallen %zu %zu %#x",
                            key.size, val.size, c);
                if (memcmp(val.data, buf, val.size) != 0)
                        errx(EXIT_FAILURE, "get badval %zu %zu %#x",
                            key.size, val.size, c);
        }
        
        len = 0xaec1;
        for (size_t i = 0; i < MAXKEY; i++) {
                key.size = (len & 0xff) + 1;
                c = len >> 8;
                memset(kb, c, key.size);
                next(&len);
                switch ((*db->del)(db, &key, 0)) {
                case 0:
                        DPRINTF("del %zu %zu %#x\n",
                            key.size, val.size, c);
                        break;
                case -1:
                        err(EXIT_FAILURE, "del %zu %zu %#x", key.size,
                            val.size, c);
                case 1:
                        errx(EXIT_FAILURE, "del not found %zu %zu %#x",
                            key.size, val.size, c);
                default:
                        abort();
                }
        }

        len = 0xaec1;
        for (size_t i = 0; i < MAXKEY; i++) {
                key.size = (len & 0xff) + 1;
                c = len >> 8;
                memset(kb, c, key.size);
                next(&len);
                switch ((*db->get)(db, &key, &val, 0)) {
                case 0:
                        errx(EXIT_FAILURE, "get2 found %zu %zu %#x",
                            key.size, val.size, c);
                        break;
                case -1:
                        err(EXIT_FAILURE, "get2 %zu %zu %#x",
                            key.size, val.size, c);
                case 1:
                        DPRINTF("get2 %zu %zu %#x\n",
                            key.size, val.size, c);
                        break;
                default:
                        abort();
                }
        }
        return 0;
}