/*
    vmem utilities.  Manipulate allocated object optimized for 
    long-term persistence over raw speed.

    Copyright (C) 2003 Robert Lipe, robertlipe@usa.net

    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 2 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, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111 USA

 */

#include "defs.h"
#include <stdlib.h>

vmem_t 
vmem_alloc(size_t size, int flags)
{
        vmem_t vm;
        /*
         * By default, zero the allocated thingy.
         */
        if (flags & VMFL_NOZERO)
                vm.mem = xmalloc(size);
        else
                vm.mem = xcalloc(size, 1);
        vm.size = size;
        return vm;
}

void
vmem_free(vmem_t *vm)
{
        if (vm->mem) xfree(vm->mem);
        vm->mem = NULL;
        vm->size = 0;
        return;
}

/*
 * We never shrink a vmem object on the premise that over time, object
 * will only grow for a while then reach a steady state.
 */
void
vmem_realloc(vmem_t *vm, size_t size)
{
        /*
         * Reallocate only if we must.
         */
        if (size > vm->size) {
                vm->mem = xrealloc(vm->mem, size);
                vm->size = size;
        }
        return;
}