/*
 *      dnsutl - utilities to make DNS easier to configure
 *      Copyright (C) 1991-1993, 1995, 1999, 2006, 2007 Peter Miller
 *
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 3 of the License, or
 *      (at your option) any later version.
 *
 *      This program is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *      GNU General Public License for more details.
 *
 *      You should have received a copy of the GNU General Public License
 *      along with this program. If not, see
 *      <http://www.gnu.org/licenses/>.
 */

#include <ac/errno.h>
#include <ac/stddef.h>
#include <ac/stdlib.h>
#include <ac/string.h>

#include <error.h>
#include <mem.h>


/*
 * NAME
 *      memory_error - diagnostic
 *
 * SYNOPSIS
 *      void memory_error(void);
 *
 * DESCRIPTION
 *      The memory_error function is used to report fatal problems with the
 *      memory allocator.
 *
 * RETURNS
 *      The memory_error function does not return.
 */

static void
memory_error(void)
{
#ifdef DEBUG
    nerror("memory allocator");
    abort();
#else
    nfatal("memory allocator");
#endif
}


/*
 * NAME
 *      mem_alloc - allocate and clear memory
 *
 * SYNOPSIS
 *      char *mem_alloc(size_t n);
 *
 * DESCRIPTION
 *      Mem_alloc uses malloc to allocate the required sized chunk of memory.
 *      If any error is returned from malloc() an fatal diagnostic is issued.
 *      The memory is zeroed befor it is returned.
 *
 * CAVEAT
 *      It is the responsibility of the caller to ensure that the space is
 *      freed when finished with, by a call to free().
 */

void *
mem_alloc(size_t n)
{
    void            *cp;

    if (n < 1)
        n = 1;
    errno = 0;
    cp = malloc(n);
    if (!cp)
    {
        if (!errno)
            errno = ENOMEM;
        memory_error();
    }
    return cp;
}


void *
mem_change_size(void *cp, size_t n)
{
    if (!cp)
        return mem_alloc(n);
    if (n < 1)
        n = 1;
    errno = 0;
    cp = realloc(cp, n);
    if (!cp)
    {
        if (!errno)
            errno = ENOMEM;
        memory_error();
    }
    return cp;
}


void
mem_free(void *cp)
{
    free(cp);
}


char *
mem_copy_string(const char *s)
{
    char            *cp;

    cp = mem_alloc(strlen(s) + 1);
    strcpy(cp, s);
    return cp;
}