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prop_bool.c revision 1.15 
      1 /*	$NetBSD: prop_bool.c,v 1.15 2008/04/28 20:22:53 martin Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2006 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <prop/prop_bool.h>
     33 #include "prop_object_impl.h"
     34 
     35 struct _prop_bool {
     36 	struct _prop_object	pb_obj;
     37 	bool		pb_value;
     38 };
     39 
     40 static struct _prop_bool _prop_bool_true;
     41 static struct _prop_bool _prop_bool_false;
     42 
     43 _PROP_MUTEX_DECL_STATIC(_prop_bool_initialized_mutex)
     44 static bool	_prop_bool_initialized;
     45 
     46 static int		_prop_bool_free(prop_stack_t, prop_object_t *);
     47 static bool	_prop_bool_externalize(
     48 				struct _prop_object_externalize_context *,
     49 				void *);
     50 static bool	_prop_bool_equals(prop_object_t, prop_object_t,
     51 				  void **, void **,
     52 				  prop_object_t *, prop_object_t *);
     53 
     54 static const struct _prop_object_type _prop_object_type_bool = {
     55 	.pot_type	=	PROP_TYPE_BOOL,
     56 	.pot_free	=	_prop_bool_free,
     57 	.pot_extern	=	_prop_bool_externalize,
     58 	.pot_equals	=	_prop_bool_equals,
     59 };
     60 
     61 #define	prop_object_is_bool(x)		\
     62 	((x) != NULL && (x)->pb_obj.po_type == &_prop_object_type_bool)
     63 
     64 /* ARGSUSED */
     65 static int
     66 _prop_bool_free(prop_stack_t stack, prop_object_t *obj)
     67 {
     68 	/*
     69 	 * This should never happen as we "leak" our initial reference
     70 	 * count.
     71 	 */
     72 
     73 	/* XXX forced assertion failure? */
     74 	return (_PROP_OBJECT_FREE_DONE);
     75 }
     76 
     77 static bool
     78 _prop_bool_externalize(struct _prop_object_externalize_context *ctx,
     79 		       void *v)
     80 {
     81 	prop_bool_t pb = v;
     82 
     83 	return (_prop_object_externalize_empty_tag(ctx,
     84 	    pb->pb_value ? "true" : "false"));
     85 }
     86 
     87 /* ARGSUSED */
     88 static bool
     89 _prop_bool_equals(prop_object_t v1, prop_object_t v2,
     90     void **stored_pointer1, void **stored_pointer2,
     91     prop_object_t *next_obj1, prop_object_t *next_obj2)
     92 {
     93 	prop_bool_t b1 = v1;
     94 	prop_bool_t b2 = v2;
     95 
     96 	if (! (prop_object_is_bool(b1) &&
     97 	       prop_object_is_bool(b2)))
     98 		return (_PROP_OBJECT_EQUALS_FALSE);
     99 
    100 	/*
    101 	 * Since we only ever allocate one true and one false,
    102 	 * save ourselves a couple of memory operations.
    103 	 */
    104 	if (b1 == b2)
    105 		return (_PROP_OBJECT_EQUALS_TRUE);
    106 	else
    107 		return (_PROP_OBJECT_EQUALS_FALSE);
    108 }
    109 
    110 static prop_bool_t
    111 _prop_bool_alloc(bool val)
    112 {
    113 	prop_bool_t pb;
    114 
    115 	if (! _prop_bool_initialized) {
    116 		_PROP_MUTEX_LOCK(_prop_bool_initialized_mutex);
    117 		if (! _prop_bool_initialized) {
    118 			_prop_object_init(&_prop_bool_true.pb_obj,
    119 					  &_prop_object_type_bool);
    120 			_prop_bool_true.pb_value = true;
    121 
    122 			_prop_object_init(&_prop_bool_false.pb_obj,
    123 					  &_prop_object_type_bool);
    124 			_prop_bool_false.pb_value = false;
    125 
    126 			_prop_bool_initialized = true;
    127 		}
    128 		_PROP_MUTEX_UNLOCK(_prop_bool_initialized_mutex);
    129 	}
    130 
    131 	pb = val ? &_prop_bool_true : &_prop_bool_false;
    132 	prop_object_retain(pb);
    133 
    134 	return (pb);
    135 }
    136 
    137 /*
    138  * prop_bool_create --
    139  *	Create a prop_bool_t and initialize it with the
    140  *	provided boolean value.
    141  */
    142 prop_bool_t
    143 prop_bool_create(bool val)
    144 {
    145 
    146 	return (_prop_bool_alloc(val));
    147 }
    148 
    149 /*
    150  * prop_bool_copy --
    151  *	Copy a prop_bool_t.
    152  */
    153 prop_bool_t
    154 prop_bool_copy(prop_bool_t opb)
    155 {
    156 
    157 	if (! prop_object_is_bool(opb))
    158 		return (NULL);
    159 
    160 	/*
    161 	 * Because we only ever allocate one true and one false, this
    162 	 * can be reduced to a simple retain operation.
    163 	 */
    164 	prop_object_retain(opb);
    165 	return (opb);
    166 }
    167 
    168 /*
    169  * prop_bool_true --
    170  *	Get the value of a prop_bool_t.
    171  */
    172 bool
    173 prop_bool_true(prop_bool_t pb)
    174 {
    175 
    176 	if (! prop_object_is_bool(pb))
    177 		return (false);
    178 
    179 	return (pb->pb_value);
    180 }
    181 
    182 /*
    183  * prop_bool_equals --
    184  *	Return true if the boolean values are equivalent.
    185  */
    186 bool
    187 prop_bool_equals(prop_bool_t b1, prop_bool_t b2)
    188 {
    189 	if (!prop_object_is_bool(b1) || !prop_object_is_bool(b2))
    190 		return (false);
    191 
    192 	return (prop_object_equals(b1, b2));
    193 }
    194 
    195 /*
    196  * _prop_bool_internalize --
    197  *	Parse a <true/> or <false/> and return the object created from
    198  *	the external representation.
    199  */
    200 
    201 /* ARGSUSED */
    202 bool
    203 _prop_bool_internalize(prop_stack_t stack, prop_object_t *obj,
    204     struct _prop_object_internalize_context *ctx)
    205 {
    206 	bool val;
    207 
    208 	/* No attributes, and it must be an empty element. */
    209 	if (ctx->poic_tagattr != NULL ||
    210 	    ctx->poic_is_empty_element == false)
    211 	    	return (true);
    212 
    213 	if (_PROP_TAG_MATCH(ctx, "true"))
    214 		val = true;
    215 	else {
    216 		_PROP_ASSERT(_PROP_TAG_MATCH(ctx, "false"));
    217 		val = false;
    218 	}
    219 	*obj = prop_bool_create(val);
    220 	return (true);
    221 }
    222