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/*
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 * Copyright © 2008 Chris Wilson <chris@chris-wilson.co.uk>
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 *
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 * This library is free software; you can redistribute it and/or
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 * modify it either under the terms of the GNU Lesser General Public
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 * License version 2.1 as published by the Free Software Foundation
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 * (the "LGPL") or, at your option, under the terms of the Mozilla
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 * Public License Version 1.1 (the "MPL"). If you do not alter this
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 * notice, a recipient may use your version of this file under either
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 * the MPL or the LGPL.
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 *
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 * You should have received a copy of the LGPL along with this library
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 * in the file COPYING-LGPL-2.1; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
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 * You should have received a copy of the MPL along with this library
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 * in the file COPYING-MPL-1.1
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 *
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 * The contents of this file are subject to the Mozilla Public License
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 * Version 1.1 (the "License"); you may not use this file except in
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 * compliance with the License. You may obtain a copy of the License at
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 * http://www.mozilla.org/MPL/
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 *
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 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
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 * OF ANY KIND, either express or implied. See the LGPL or the MPL for
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 * the specific language governing rights and limitations.
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 *
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 * The Original Code is the cairo graphics library.
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 *
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 * The Initial Developer of the Original Code is Chris Wilson.
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 *
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 * Contributor(s):
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 *	Chris Wilson <chris@chris-wilson.co.uk>
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 */
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#include "config.h"
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#include "cairo-script-private.h"
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#include <limits.h> /* INT_MAX */
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#include <string.h>
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csi_status_t
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_csi_stack_init (csi_t *ctx, csi_stack_t *stack, csi_integer_t size)
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{
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    csi_status_t status = CSI_STATUS_SUCCESS;
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    stack->len = 0;
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    stack->size = size;
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    /* assert ((unsigned) size < INT_MAX / sizeof (csi_object_t)); */
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    stack->objects = _csi_alloc (ctx, size * sizeof (csi_object_t));
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    if (_csi_unlikely (stack->objects == NULL))
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	status = _csi_error (CSI_STATUS_NO_MEMORY);
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    return status;
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}
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void
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_csi_stack_fini (csi_t *ctx, csi_stack_t *stack)
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{
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    csi_integer_t n;
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    for (n = 0; n < stack->len; n++)
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	csi_object_free (ctx, &stack->objects[n]);
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    _csi_free (ctx, stack->objects);
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}
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csi_status_t
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_csi_stack_roll (csi_t *ctx,
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		 csi_stack_t *stack,
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		 csi_integer_t mod, csi_integer_t n)
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{
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    csi_object_t stack_copy[128];
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    csi_object_t *copy;
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    csi_integer_t last, i, len;
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    switch (mod) { /* special cases */
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    case 1:
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	last = stack->len - 1;
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	stack_copy[0] = stack->objects[last];
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	for (i = last; --n; i--)
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	    stack->objects[i] = stack->objects[i-1];
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	stack->objects[i] = stack_copy[0];
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	return CSI_STATUS_SUCCESS;
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    case -1:
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	last = stack->len - 1;
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	stack_copy[0] = stack->objects[i = last - n + 1];
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	for (; --n; i++)
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	    stack->objects[i] = stack->objects[i+1];
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	stack->objects[i] = stack_copy[0];
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	return CSI_STATUS_SUCCESS;
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    }
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    /* fall back to a copy */
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    if (n > ARRAY_LENGTH (stack_copy)) {
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	if (_csi_unlikely ((unsigned) n > INT_MAX / sizeof (csi_object_t)))
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	    return _csi_error (CSI_STATUS_NO_MEMORY);
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	copy = _csi_alloc (ctx, n * sizeof (csi_object_t));
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	if (copy == NULL)
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	    return _csi_error (CSI_STATUS_NO_MEMORY);
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    } else
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	copy = stack_copy;
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    i = stack->len - n;
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    memcpy (copy, stack->objects + i, n * sizeof (csi_object_t));
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    mod = -mod;
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    if (mod < 0)
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	mod += n;
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    last = mod;
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    for (len = n; n--; i++) {
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	stack->objects[i] = copy[last];
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	if (++last == len)
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	    last = 0;
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    }
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    if (copy != stack_copy)
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	_csi_free (ctx, copy);
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    return CSI_STATUS_SUCCESS;
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}
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csi_status_t
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_csi_stack_grow (csi_t *ctx, csi_stack_t *stack, csi_integer_t cnt)
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{
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    csi_integer_t newsize;
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    csi_object_t *newstack;
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    if (_csi_likely (cnt <= stack->size))
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	return CSI_STATUS_SUCCESS;
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    if (_csi_unlikely ((unsigned) cnt >= INT_MAX / sizeof (csi_object_t)))
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	return _csi_error (CSI_STATUS_NO_MEMORY);
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    newsize = stack->size;
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    do {
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	newsize *= 2;
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    } while (newsize <= cnt);
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    newstack = _csi_realloc (ctx,
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			     stack->objects,
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			     newsize * sizeof (csi_object_t));
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    if (_csi_unlikely (newstack == NULL))
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	return _csi_error (CSI_STATUS_NO_MEMORY);
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    stack->objects = newstack;
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    stack->size  = newsize;
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    return CSI_STATUS_SUCCESS;
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}
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csi_status_t
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_csi_stack_push_internal (csi_t *ctx, csi_stack_t *stack,
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			  const csi_object_t *obj)
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{
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    csi_status_t status;
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    status = _csi_stack_grow (ctx, stack, stack->size + 1);
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    if (_csi_unlikely (status))
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	return status;
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    stack->objects[stack->len++] = *obj;
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    return CSI_STATUS_SUCCESS;
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}
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csi_object_t *
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_csi_stack_peek (csi_stack_t *stack, csi_integer_t i)
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{
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    if (_csi_unlikely (stack->len < i))
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	return NULL;
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    return &stack->objects[stack->len - i -1];
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}
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void
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_csi_stack_pop (csi_t *ctx, csi_stack_t *stack, csi_integer_t count)
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{
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    if (_csi_unlikely (stack->len < count))
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	count = stack->len;
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    while (count--)
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	csi_object_free (ctx, &stack->objects[--stack->len]);
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}
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csi_status_t
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_csi_stack_exch (csi_stack_t *stack)
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{
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    csi_object_t tmp;
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    csi_integer_t n;
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    if (_csi_unlikely (stack->len < 2))
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	return _csi_error (CSI_STATUS_INVALID_SCRIPT);
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    n = stack->len - 1;
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    tmp = stack->objects[n];
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    stack->objects[n] = stack->objects[n - 1];
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    stack->objects[n - 1] = tmp;
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    return CSI_STATUS_SUCCESS;
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}