/* This file is part of the cqual.
   Copyright (C) 2000-2001 The Regents of the University of California.

cqual 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, or (at your option)
any later version.

cqual 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 cqual; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include <regions.h>
#include <assert.h>
#include <limits.h>
#include "array.h"

struct array {
  region sameregion r;
  void *sameregion data;
  size_t elemsize;
  type_t elemtype;
  size_t nelems, nalloc;
};

struct array *new_array(region r, size_t initialsize,
			size_t typesize, type_t typeinfo)
{
  struct array *a = ralloc(r, struct array);

  a->r = r;
  a->data = typed_rarrayalloc(r, initialsize, typesize, typeinfo);
  a->elemsize = typesize;
  a->elemtype = typeinfo;
  a->nelems = 0;
  a->nalloc = initialsize;

  return a;
}

void *array_extend(struct array *a, int by)
{
  size_t oldelems = a->nelems;

  if (by < 0)
    assert(-by <= a->nelems && by != INT_MIN);
  else if (a->nelems + by > a->nalloc)
    {
      size_t newsize = a->nalloc * 2 + by;
      void *newdata = typed_rarrayalloc(a->r, newsize, a->elemsize, a->elemtype);

      /* XXX: could work harder to support really large array sizes
	 (this code will fail for a->nalloc >= (max(size_t)-by)/2) */
      assert(newsize > a->nalloc); /* die when we get really big */
      typed_rarraycopy(newdata, a->data, a->nelems, a->elemsize, a->elemtype);
      a->data = newdata;
      a->nalloc = newsize;
    }
  a->nelems += by;

  return (char *)a->data + a->elemsize * oldelems;
}

void array_reset(struct array *a)
{
  a->nelems = 0;
}

size_t array_length(struct array *a)
{
  return a->nelems;
}

void *array_data(struct array *a)
{
  return a->data;
}

