prop_stack.c revision 1.1 
1/* $NetBSD: prop_stack.c,v 1.1 2007/08/16 21:44:08 joerg Exp $ */
2
3/*-
4 * Copyright (c) 2007 Joerg Sonnenberger <joerg@NetBSD.org>.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in
15 *    the documentation and/or other materials provided with the
16 *    distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
22 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
24 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
28 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include "prop_stack.h"
33#include "prop_object_impl.h"
34
35void
36_prop_stack_init(prop_stack_t stack)
37{
38	stack->used_intern_elems = 0;
39	SLIST_INIT(&stack->extern_elems);
40}
41
42bool
43_prop_stack_push(prop_stack_t stack, prop_object_t obj, void *obj_data, void *iter)
44{
45	struct _prop_stack_extern_elem *eelem;
46	struct _prop_stack_intern_elem *ielem;
47
48	if (stack->used_intern_elems == PROP_STACK_INTERN_ELEMS) {
49		eelem = _PROP_MALLOC(sizeof(*eelem), M_TEMP);
50
51		if (eelem == NULL)
52			return false;
53
54		eelem->object = obj;
55		eelem->object_data = obj_data;
56		eelem->iterator = iter;
57
58		SLIST_INSERT_HEAD(&stack->extern_elems, eelem, stack_link);
59
60		return true;
61	}
62
63	_PROP_ASSERT(stack->used_intern_elems < PROP_STACK_INTERN_ELEMS);
64	_PROP_ASSERT(SLIST_EMPTY(&stack->extern_elems));
65
66	ielem = &stack->intern_elems[stack->used_intern_elems];
67	ielem->object = obj;
68	ielem->object_data = obj_data;
69	ielem->iterator = iter;
70
71	++stack->used_intern_elems;
72
73	return true;
74}
75
76bool
77_prop_stack_pop(prop_stack_t stack, prop_object_t *obj, void **obj_data, void **iter)
78{
79	struct _prop_stack_extern_elem *eelem;
80	struct _prop_stack_intern_elem *ielem;
81
82	if (stack->used_intern_elems == 0)
83		return false;
84
85	if ((eelem = SLIST_FIRST(&stack->extern_elems)) != NULL) {
86		_PROP_ASSERT(stack->used_intern_elems == PROP_STACK_INTERN_ELEMS);
87
88		SLIST_REMOVE_HEAD(&stack->extern_elems, stack_link);
89		*obj = eelem->object;
90		*obj_data = eelem->object_data;
91		*iter = eelem->iterator;
92		_PROP_FREE(eelem, M_TEMP);
93		return true;
94	}
95
96	--stack->used_intern_elems;
97	ielem = &stack->intern_elems[stack->used_intern_elems];
98
99	*obj = ielem->object;
100	*obj_data = ielem->object_data;
101	*iter = ielem->iterator;
102
103	return true;
104}
105