prop_stack.c revision 1.1.2.1 
1/* $NetBSD: prop_stack.c,v 1.1.2.1 2007/11/06 23:07:28 matt 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 *data1,
44    void *data2, void *data3)
45{
46	struct _prop_stack_extern_elem *eelem;
47	struct _prop_stack_intern_elem *ielem;
48
49	if (stack->used_intern_elems == PROP_STACK_INTERN_ELEMS) {
50		eelem = _PROP_MALLOC(sizeof(*eelem), M_TEMP);
51
52		if (eelem == NULL)
53			return false;
54
55		eelem->object = obj;
56		eelem->object_data[0] = data1;
57		eelem->object_data[1] = data2;
58		eelem->object_data[2] = data3;
59
60		SLIST_INSERT_HEAD(&stack->extern_elems, eelem, stack_link);
61
62		return true;
63	}
64
65	_PROP_ASSERT(stack->used_intern_elems < PROP_STACK_INTERN_ELEMS);
66	_PROP_ASSERT(SLIST_EMPTY(&stack->extern_elems));
67
68	ielem = &stack->intern_elems[stack->used_intern_elems];
69	ielem->object = obj;
70	ielem->object_data[0] = data1;
71	ielem->object_data[1] = data2;
72	ielem->object_data[2] = data3;
73
74	++stack->used_intern_elems;
75
76	return true;
77}
78
79bool
80_prop_stack_pop(prop_stack_t stack, prop_object_t *obj, void **data1,
81    void **data2, void **data3)
82{
83	struct _prop_stack_extern_elem *eelem;
84	struct _prop_stack_intern_elem *ielem;
85
86	if (stack->used_intern_elems == 0)
87		return false;
88
89	if ((eelem = SLIST_FIRST(&stack->extern_elems)) != NULL) {
90		_PROP_ASSERT(stack->used_intern_elems == PROP_STACK_INTERN_ELEMS);
91
92		SLIST_REMOVE_HEAD(&stack->extern_elems, stack_link);
93		if (obj)
94			*obj = eelem->object;
95		if (data1)
96			*data1 = eelem->object_data[0];
97		if (data2)
98			*data2 = eelem->object_data[1];
99		if (data3)
100			*data3 = eelem->object_data[2];
101		_PROP_FREE(eelem, M_TEMP);
102		return true;
103	}
104
105	--stack->used_intern_elems;
106	ielem = &stack->intern_elems[stack->used_intern_elems];
107
108	if (obj)
109		*obj = ielem->object;
110	if (data1)
111		*data1 = ielem->object_data[0];
112	if (data2)
113		*data2 = ielem->object_data[1];
114	if (data3)
115		*data3 = ielem->object_data[2];
116
117	return true;
118}
119