/*

 * Copyright © 2008 Chris Wilson <chris@chris-wilson.co.uk>

 *

 * This library is free software; you can redistribute it and/or

 * modify it either under the terms of the GNU Lesser General Public

 * License version 2.1 as published by the Free Software Foundation

 * (the "LGPL") or, at your option, under the terms of the Mozilla

 * Public License Version 1.1 (the "MPL"). If you do not alter this

 * notice, a recipient may use your version of this file under either

 * the MPL or the LGPL.

 *

 * You should have received a copy of the LGPL along with this library

 * in the file COPYING-LGPL-2.1; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA

 * You should have received a copy of the MPL along with this library

 * in the file COPYING-MPL-1.1

 *

 * The contents of this file are subject to the Mozilla Public License

 * Version 1.1 (the "License"); you may not use this file except in

 * compliance with the License. You may obtain a copy of the License at

 * http://www.mozilla.org/MPL/

 *

 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY

 * OF ANY KIND, either express or implied. See the LGPL or the MPL for

 * the specific language governing rights and limitations.

 *

 * The Original Code is the cairo graphics library.

 *

 * The Initial Developer of the Original Code is Chris Wilson.

 *

 * Contributor(s):

 *  Chris Wilson <chris@chris-wilson.co.uk>

 */

#include "config.h"

#include "cairo-script-private.h"

#include <limits.h> /* INT_MAX */

#include <string.h>

csi_status_t

_csi_stack_init (csi_t *ctx, csi_stack_t *stack, csi_integer_t size)

{

    csi_status_t status = CSI_STATUS_SUCCESS;

    stack->len = 0;

    stack->size = size;

    /* assert ((unsigned) size < INT_MAX / sizeof (csi_object_t)); */

    stack->objects = _csi_alloc (ctx, size * sizeof (csi_object_t));

    if (_csi_unlikely (stack->objects == NULL))

  status = _csi_error (CSI_STATUS_NO_MEMORY);

    return status;

}

void

_csi_stack_fini (csi_t *ctx, csi_stack_t *stack)

{

    csi_integer_t n;

    for (n = 0; n < stack->len; n++)

  csi_object_free (ctx, &stack->objects[n]);

    _csi_free (ctx, stack->objects);

}

csi_status_t

_csi_stack_roll (csi_t *ctx,

     csi_stack_t *stack,

     csi_integer_t mod, csi_integer_t n)

{

    csi_object_t stack_copy[128];

    csi_object_t *copy;

    csi_integer_t last, i, len;

    switch (mod) { /* special cases */

    case 1:

  last = stack->len - 1;

  stack_copy[0] = stack->objects[last];

  for (i = last; --n; i--)

      stack->objects[i] = stack->objects[i-1];

  stack->objects[i] = stack_copy[0];

  return CSI_STATUS_SUCCESS;

    case -1:

  last = stack->len - 1;

  stack_copy[0] = stack->objects[i = last - n + 1];

  for (; --n; i++)

      stack->objects[i] = stack->objects[i+1];

  stack->objects[i] = stack_copy[0];

  return CSI_STATUS_SUCCESS;

    }

    /* fall back to a copy */

    if (n > ARRAY_LENGTH (stack_copy)) {

  if (_csi_unlikely ((unsigned) n > INT_MAX / sizeof (csi_object_t)))

      return _csi_error (CSI_STATUS_NO_MEMORY);

  copy = _csi_alloc (ctx, n * sizeof (csi_object_t));

  if (copy == NULL)

      return _csi_error (CSI_STATUS_NO_MEMORY);

    } else

  copy = stack_copy;

    i = stack->len - n;

    memcpy (copy, stack->objects + i, n * sizeof (csi_object_t));

    mod = -mod;

    if (mod < 0)

  mod += n;

    last = mod;

    for (len = n; n--; i++) {

  stack->objects[i] = copy[last];

  if (++last == len)

      last = 0;

    }

    if (copy != stack_copy)

  _csi_free (ctx, copy);

    return CSI_STATUS_SUCCESS;

}

csi_status_t

_csi_stack_grow (csi_t *ctx, csi_stack_t *stack, csi_integer_t cnt)

{

    csi_integer_t newsize;

    csi_object_t *newstack;

    if (_csi_likely (cnt <= stack->size))

  return CSI_STATUS_SUCCESS;

    if (_csi_unlikely ((unsigned) cnt >= INT_MAX / sizeof (csi_object_t)))

  return _csi_error (CSI_STATUS_NO_MEMORY);

    newsize = stack->size;

    do {

  newsize *= 2;

    } while (newsize <= cnt);

    newstack = _csi_realloc (ctx,

           stack->objects,

           newsize * sizeof (csi_object_t));

    if (_csi_unlikely (newstack == NULL))

  return _csi_error (CSI_STATUS_NO_MEMORY);

    stack->objects = newstack;

    stack->size  = newsize;

    return CSI_STATUS_SUCCESS;

}

csi_status_t

_csi_stack_push_internal (csi_t *ctx, csi_stack_t *stack,

        const csi_object_t *obj)

{

    csi_status_t status;

    status = _csi_stack_grow (ctx, stack, stack->size + 1);

    if (_csi_unlikely (status))

  return status;

    stack->objects[stack->len++] = *obj;

    return CSI_STATUS_SUCCESS;

}

csi_object_t *

_csi_stack_peek (csi_stack_t *stack, csi_integer_t i)

{

    if (_csi_unlikely (stack->len < i))

  return NULL;

    return &stack->objects[stack->len - i -1];

}

void

_csi_stack_pop (csi_t *ctx, csi_stack_t *stack, csi_integer_t count)

{

    if (_csi_unlikely (stack->len < count))

  count = stack->len;

    while (count--)

  csi_object_free (ctx, &stack->objects[--stack->len]);

}

csi_status_t

_csi_stack_exch (csi_stack_t *stack)

{

    csi_object_t tmp;

    csi_integer_t n;

    if (_csi_unlikely (stack->len < 2))

  return _csi_error (CSI_STATUS_INVALID_SCRIPT);

    n = stack->len - 1;

    tmp = stack->objects[n];

    stack->objects[n] = stack->objects[n - 1];

    stack->objects[n - 1] = tmp;

    return CSI_STATUS_SUCCESS;

}