/* $Id: dba_array.c,v 1.2 2020/06/22 19:20:40 schwarze Exp $ */
/*
 * Copyright (c) 2016 Ingo Schwarze <schwarze@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Allocation-based arrays for the mandoc database, for read-write access.
 * The interface is defined in "dba_array.h".
 */
#include "config.h"

#include <assert.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include "mandoc_aux.h"
#include "dba_write.h"
#include "dba_array.h"

struct dba_array {
        void    **ep;   /* Array of entries. */
        int32_t  *em;   /* Array of map positions. */
        int       flags;
        int32_t   ea;   /* Entries allocated. */
        int32_t   eu;   /* Entries used (including deleted). */
        int32_t   ed;   /* Entries deleted. */
        int32_t   ec;   /* Currently active entry. */
        int32_t   pos;  /* Map position of this array. */
};


struct dba_array *
dba_array_new(int32_t ea, int flags)
{
        struct dba_array        *array;

        assert(ea > 0);
        array = mandoc_malloc(sizeof(*array));
        array->ep = mandoc_reallocarray(NULL, ea, sizeof(*array->ep));
        array->em = mandoc_reallocarray(NULL, ea, sizeof(*array->em));
        array->ea = ea;
        array->eu = 0;
        array->ed = 0;
        array->ec = 0;
        array->flags = flags;
        array->pos = 0;
        return array;
}

void
dba_array_free(struct dba_array *array)
{
        int32_t  ie;

        if (array == NULL)
                return;
        if (array->flags & DBA_STR)
                for (ie = 0; ie < array->eu; ie++)
                        free(array->ep[ie]);
        free(array->ep);
        free(array->em);
        free(array);
}

void
dba_array_set(struct dba_array *array, int32_t ie, void *entry)
{
        assert(ie >= 0);
        assert(ie < array->ea);
        assert(ie <= array->eu);
        if (ie == array->eu)
                array->eu++;
        if (array->flags & DBA_STR)
                entry = mandoc_strdup(entry);
        array->ep[ie] = entry;
        array->em[ie] = 0;
}

void
dba_array_add(struct dba_array *array, void *entry)
{
        if (array->eu == array->ea) {
                assert(array->flags & DBA_GROW);
                array->ep = mandoc_reallocarray(array->ep,
                    2, sizeof(*array->ep) * array->ea);
                array->em = mandoc_reallocarray(array->em,
                    2, sizeof(*array->em) * array->ea);
                array->ea *= 2;
        }
        dba_array_set(array, array->eu, entry);
}

void *
dba_array_get(struct dba_array *array, int32_t ie)
{
        if (ie < 0 || ie >= array->eu || array->em[ie] == -1)
                return NULL;
        return array->ep[ie];
}

void
dba_array_start(struct dba_array *array)
{
        array->ec = array->eu;
}

void *
dba_array_next(struct dba_array *array)
{
        if (array->ec < array->eu)
                array->ec++;
        else
                array->ec = 0;
        while (array->ec < array->eu && array->em[array->ec] == -1)
                array->ec++;
        return array->ec < array->eu ? array->ep[array->ec] : NULL;
}

void
dba_array_del(struct dba_array *array)
{
        if (array->ec < array->eu && array->em[array->ec] != -1) {
                array->em[array->ec] = -1;
                array->ed++;
        }
}

void
dba_array_undel(struct dba_array *array)
{
        memset(array->em, 0, sizeof(*array->em) * array->eu);
}

void
dba_array_setpos(struct dba_array *array, int32_t ie, int32_t pos)
{
        array->em[ie] = pos;
}

int32_t
dba_array_getpos(struct dba_array *array)
{
        return array->pos;
}

void
dba_array_sort(struct dba_array *array, dba_compare_func func)
{
        assert(array->ed == 0);
        qsort(array->ep, array->eu, sizeof(*array->ep), func);
}

int32_t
dba_array_writelen(struct dba_array *array, int32_t nmemb)
{
        dba_int_write(array->eu - array->ed);
        return dba_skip(nmemb, array->eu - array->ed);
}

void
dba_array_writepos(struct dba_array *array)
{
        int32_t  ie;

        array->pos = dba_tell();
        for (ie = 0; ie < array->eu; ie++)
                if (array->em[ie] != -1)
                        dba_int_write(array->em[ie]);
}

void
dba_array_writelst(struct dba_array *array)
{
        const char      *str;

        dba_array_FOREACH(array, str)
                dba_str_write(str);
        dba_char_write('\0');
}