Home | History | Annotate | Line # | Download | only in libprop
prop_stack.c revision 1.2 
      1 /* $NetBSD: prop_stack.c,v 1.2 2007/08/30 12:23:54 joerg Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2007 Joerg Sonnenberger <joerg (at) 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 
     35 void
     36 _prop_stack_init(prop_stack_t stack)
     37 {
     38 	stack->used_intern_elems = 0;
     39 	SLIST_INIT(&stack->extern_elems);
     40 }
     41 
     42 bool
     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 
     79 bool
     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