/*      $NetBSD: citrus_db_factory.c,v 1.10 2013/09/14 13:05:51 joerg Exp $     */

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c)2003 Citrus Project,
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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/types.h>
#include <sys/queue.h>

#include <arpa/inet.h>
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "citrus_namespace.h"
#include "citrus_region.h"
#include "citrus_db_file.h"
#include "citrus_db_factory.h"

struct _citrus_db_factory_entry {
        STAILQ_ENTRY(_citrus_db_factory_entry)   de_entry;
        struct _citrus_db_factory_entry         *de_next;
        uint32_t                                 de_hashvalue;
        struct _region                           de_key;
        int                                      de_key_free;
        struct _region                           de_data;
        int                                      de_data_free;
        int                                     de_idx;
};

struct _citrus_db_factory {
        size_t                                   df_num_entries;
        STAILQ_HEAD(, _citrus_db_factory_entry)  df_entries;
        size_t                                   df_total_key_size;
        size_t                                   df_total_data_size;
        uint32_t (*df_hashfunc)(struct _citrus_region *);
        void                                    *df_hashfunc_closure;
};

#define DB_ALIGN 16

int
_citrus_db_factory_create(struct _citrus_db_factory **rdf,
    _citrus_db_hash_func_t hashfunc, void *hashfunc_closure)
{
        struct _citrus_db_factory *df;

        df = malloc(sizeof(*df));
        if (df == NULL)
                return (errno);
        df->df_num_entries = 0;
        df->df_total_key_size = df->df_total_data_size = 0;
        STAILQ_INIT(&df->df_entries);
        df->df_hashfunc = hashfunc;
        df->df_hashfunc_closure = hashfunc_closure;

        *rdf = df;

        return (0);
}

void
_citrus_db_factory_free(struct _citrus_db_factory *df)
{
        struct _citrus_db_factory_entry *de;

        while ((de = STAILQ_FIRST(&df->df_entries)) != NULL) {
                STAILQ_REMOVE_HEAD(&df->df_entries, de_entry);
                if (de->de_key_free)
                        free(_region_head(&de->de_key));
                if (de->de_data_free)
                        free(_region_head(&de->de_data));
                free(de);
        }
        free(df);
}

static __inline size_t
ceilto(size_t sz)
{
        return ((sz + DB_ALIGN - 1) & ~(DB_ALIGN - 1));
}

int
_citrus_db_factory_add(struct _citrus_db_factory *df, struct _region *key,
    int keyfree, struct _region *data, int datafree)
{
        struct _citrus_db_factory_entry *de;

        de = malloc(sizeof(*de));
        if (de == NULL)
                return (-1);

        de->de_hashvalue = df->df_hashfunc(key);
        de->de_key = *key;
        de->de_key_free = keyfree;
        de->de_data = *data;
        de->de_data_free = datafree;
        de->de_idx = -1;

        STAILQ_INSERT_TAIL(&df->df_entries, de, de_entry);
        df->df_total_key_size += _region_size(key);
        df->df_total_data_size += ceilto(_region_size(data));
        df->df_num_entries++;

        return (0);

}

int
_citrus_db_factory_add_by_string(struct _citrus_db_factory *df,
    const char *key, struct _citrus_region *data, int datafree)
{
        struct _region r;
        char *tmp;

        tmp = strdup(key);
        if (tmp == NULL)
                return (errno);
        _region_init(&r, tmp, strlen(key));
        return _citrus_db_factory_add(df, &r, 1, data, datafree);
}

int
_citrus_db_factory_add8_by_string(struct _citrus_db_factory *df,
    const char *key, uint8_t val)
{
        struct _region r;
        uint8_t *p;

        p = malloc(sizeof(*p));
        if (p == NULL)
                return (errno);
        *p = val;
        _region_init(&r, p, 1);
        return (_citrus_db_factory_add_by_string(df, key, &r, 1));
}

int
_citrus_db_factory_add16_by_string(struct _citrus_db_factory *df,
    const char *key, uint16_t val)
{
        struct _region r;
        uint16_t *p;

        p = malloc(sizeof(*p));
        if (p == NULL)
                return (errno);
        *p = htons(val);
        _region_init(&r, p, 2);
        return (_citrus_db_factory_add_by_string(df, key, &r, 1));
}

int
_citrus_db_factory_add32_by_string(struct _citrus_db_factory *df,
    const char *key, uint32_t val)
{
        struct _region r;
        uint32_t *p;

        p = malloc(sizeof(*p));
        if (p == NULL)
                return (errno);
        *p = htonl(val);
        _region_init(&r, p, 4);
        return (_citrus_db_factory_add_by_string(df, key, &r, 1));
}

int
_citrus_db_factory_add_string_by_string(struct _citrus_db_factory *df,
    const char *key, const char *data)
{
        char *p;
        struct _region r;

        p = strdup(data);
        if (p == NULL)
                return (errno);
        _region_init(&r, p, strlen(p) + 1);
        return (_citrus_db_factory_add_by_string(df, key, &r, 1));
}

size_t
_citrus_db_factory_calc_size(struct _citrus_db_factory *df)
{
        size_t sz;

        sz = ceilto(_CITRUS_DB_HEADER_SIZE);
        sz += ceilto(_CITRUS_DB_ENTRY_SIZE * df->df_num_entries);
        sz += ceilto(df->df_total_key_size);
        sz += df->df_total_data_size;

        return (sz);
}

static __inline void
put8(struct _region *r, size_t *rofs, uint8_t val)
{

        *(uint8_t *)_region_offset(r, *rofs) = val;
        *rofs += 1;
}

static __inline void
put32(struct _region *r, size_t *rofs, uint32_t val)
{

        val = htonl(val);
        memcpy(_region_offset(r, *rofs), &val, 4);
        *rofs += 4;
}

static __inline void
putpad(struct _region *r, size_t *rofs)
{
        size_t i;

        for (i = ceilto(*rofs) - *rofs; i > 0; i--)
                put8(r, rofs, 0);
}

static __inline void
dump_header(struct _region *r, const char *magic, size_t *rofs,
    size_t num_entries)
{

        while (*rofs<_CITRUS_DB_MAGIC_SIZE)
                put8(r, rofs, *magic++);
        put32(r, rofs, num_entries);
        put32(r, rofs, _CITRUS_DB_HEADER_SIZE);
}

int
_citrus_db_factory_serialize(struct _citrus_db_factory *df, const char *magic,
    struct _region *r)
{
        struct _citrus_db_factory_entry *de, **depp, *det;
        size_t dataofs, i, keyofs, nextofs, ofs;

        ofs = 0;
        /* check whether more than 0 entries exist */
        if (df->df_num_entries == 0) {
                dump_header(r, magic, &ofs, 0);
                return (0);
        }
        /* allocate hash table */
        depp = calloc(df->df_num_entries, sizeof(*depp));
        if (depp == NULL)
                return (-1);

        /* step1: store the entries which are not conflicting */
        STAILQ_FOREACH(de, &df->df_entries, de_entry) {
                de->de_hashvalue %= df->df_num_entries;
                de->de_idx = -1;
                de->de_next = NULL;
                if (depp[de->de_hashvalue] == NULL) {
                        depp[de->de_hashvalue] = de;
                        de->de_idx = (int)de->de_hashvalue;
                }
        }

        /* step2: resolve conflicts */
        i = 0;
        STAILQ_FOREACH(de, &df->df_entries, de_entry) {
                if (de->de_idx == -1) {
                        det = depp[de->de_hashvalue];
                        while (det->de_next != NULL)
                                det = det->de_next;
                        det->de_next = de;
                        while (depp[i] != NULL)
                                i++;
                        depp[i] = de;
                        de->de_idx = (int)i;
                }
        }

        keyofs = _CITRUS_DB_HEADER_SIZE +
            ceilto(df->df_num_entries*_CITRUS_DB_ENTRY_SIZE);
        dataofs = keyofs + ceilto(df->df_total_key_size);

        /* dump header */
        dump_header(r, magic, &ofs, df->df_num_entries);

        /* dump entries */
        for (i = 0; i < df->df_num_entries; i++) {
                de = depp[i];
                nextofs = 0;
                if (de->de_next) {
                        nextofs = _CITRUS_DB_HEADER_SIZE +
                            de->de_next->de_idx * _CITRUS_DB_ENTRY_SIZE;
                }
                put32(r, &ofs, de->de_hashvalue);
                put32(r, &ofs, nextofs);
                put32(r, &ofs, keyofs);
                put32(r, &ofs, _region_size(&de->de_key));
                put32(r, &ofs, dataofs);
                put32(r, &ofs, _region_size(&de->de_data));
                memcpy(_region_offset(r, keyofs),
                    _region_head(&de->de_key), _region_size(&de->de_key));
                keyofs += _region_size(&de->de_key);
                memcpy(_region_offset(r, dataofs),
                    _region_head(&de->de_data), _region_size(&de->de_data));
                dataofs += _region_size(&de->de_data);
                putpad(r, &dataofs);
        }
        putpad(r, &ofs);
        putpad(r, &keyofs);
        free(depp);

        return (0);
}