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prop_bool.c revision 1.13 
      1 /*	$NetBSD: prop_bool.c,v 1.13 2008/01/04 21:35:18 xtraeme 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  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *      This product includes software developed by the NetBSD
     21  *      Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/simplelock.h>
     40 
     41 #include <prop/prop_bool.h>
     42 #include "prop_object_impl.h"
     43 
     44 struct _prop_bool {
     45 	struct _prop_object	pb_obj;
     46 	bool		pb_value;
     47 };
     48 
     49 static struct _prop_bool _prop_bool_true;
     50 static struct _prop_bool _prop_bool_false;
     51 
     52 _PROP_MUTEX_DECL_STATIC(_prop_bool_initialized_mutex)
     53 static bool	_prop_bool_initialized;
     54 
     55 static int		_prop_bool_free(prop_stack_t, prop_object_t *);
     56 static bool	_prop_bool_externalize(
     57 				struct _prop_object_externalize_context *,
     58 				void *);
     59 static bool	_prop_bool_equals(prop_object_t, prop_object_t,
     60 				  void **, void **,
     61 				  prop_object_t *, prop_object_t *);
     62 
     63 static const struct _prop_object_type _prop_object_type_bool = {
     64 	.pot_type	=	PROP_TYPE_BOOL,
     65 	.pot_free	=	_prop_bool_free,
     66 	.pot_extern	=	_prop_bool_externalize,
     67 	.pot_equals	=	_prop_bool_equals,
     68 };
     69 
     70 #define	prop_object_is_bool(x)		\
     71 	((x) != NULL && (x)->pb_obj.po_type == &_prop_object_type_bool)
     72 
     73 /* ARGSUSED */
     74 static int
     75 _prop_bool_free(prop_stack_t stack, prop_object_t *obj)
     76 {
     77 	/*
     78 	 * This should never happen as we "leak" our initial reference
     79 	 * count.
     80 	 */
     81 
     82 	/* XXX forced assertion failure? */
     83 	return (_PROP_OBJECT_FREE_DONE);
     84 }
     85 
     86 static bool
     87 _prop_bool_externalize(struct _prop_object_externalize_context *ctx,
     88 		       void *v)
     89 {
     90 	prop_bool_t pb = v;
     91 
     92 	return (_prop_object_externalize_empty_tag(ctx,
     93 	    pb->pb_value ? "true" : "false"));
     94 }
     95 
     96 /* ARGSUSED */
     97 static bool
     98 _prop_bool_equals(prop_object_t v1, prop_object_t v2,
     99     void **stored_pointer1, void **stored_pointer2,
    100     prop_object_t *next_obj1, prop_object_t *next_obj2)
    101 {
    102 	prop_bool_t b1 = v1;
    103 	prop_bool_t b2 = v2;
    104 
    105 	if (! (prop_object_is_bool(b1) &&
    106 	       prop_object_is_bool(b2)))
    107 		return (_PROP_OBJECT_EQUALS_FALSE);
    108 
    109 	/*
    110 	 * Since we only ever allocate one true and one false,
    111 	 * save ourselves a couple of memory operations.
    112 	 */
    113 	if (b1 == b2)
    114 		return (_PROP_OBJECT_EQUALS_TRUE);
    115 	else
    116 		return (_PROP_OBJECT_EQUALS_FALSE);
    117 }
    118 
    119 static prop_bool_t
    120 _prop_bool_alloc(bool val)
    121 {
    122 	prop_bool_t pb;
    123 
    124 	if (! _prop_bool_initialized) {
    125 		_PROP_MUTEX_LOCK(_prop_bool_initialized_mutex);
    126 		if (! _prop_bool_initialized) {
    127 			_prop_object_init(&_prop_bool_true.pb_obj,
    128 					  &_prop_object_type_bool);
    129 			_prop_bool_true.pb_value = true;
    130 
    131 			_prop_object_init(&_prop_bool_false.pb_obj,
    132 					  &_prop_object_type_bool);
    133 			_prop_bool_false.pb_value = false;
    134 
    135 			_prop_bool_initialized = true;
    136 		}
    137 		_PROP_MUTEX_UNLOCK(_prop_bool_initialized_mutex);
    138 	}
    139 
    140 	pb = val ? &_prop_bool_true : &_prop_bool_false;
    141 	prop_object_retain(pb);
    142 
    143 	return (pb);
    144 }
    145 
    146 /*
    147  * prop_bool_create --
    148  *	Create a prop_bool_t and initialize it with the
    149  *	provided boolean value.
    150  */
    151 prop_bool_t
    152 prop_bool_create(bool val)
    153 {
    154 
    155 	return (_prop_bool_alloc(val));
    156 }
    157 
    158 /*
    159  * prop_bool_copy --
    160  *	Copy a prop_bool_t.
    161  */
    162 prop_bool_t
    163 prop_bool_copy(prop_bool_t opb)
    164 {
    165 
    166 	if (! prop_object_is_bool(opb))
    167 		return (NULL);
    168 
    169 	/*
    170 	 * Because we only ever allocate one true and one false, this
    171 	 * can be reduced to a simple retain operation.
    172 	 */
    173 	prop_object_retain(opb);
    174 	return (opb);
    175 }
    176 
    177 /*
    178  * prop_bool_true --
    179  *	Get the value of a prop_bool_t.
    180  */
    181 bool
    182 prop_bool_true(prop_bool_t pb)
    183 {
    184 
    185 	if (! prop_object_is_bool(pb))
    186 		return (false);
    187 
    188 	return (pb->pb_value);
    189 }
    190 
    191 /*
    192  * prop_bool_equals --
    193  *	Return true if the boolean values are equivalent.
    194  */
    195 bool
    196 prop_bool_equals(prop_bool_t b1, prop_bool_t b2)
    197 {
    198 	if (!prop_object_is_bool(b1) || !prop_object_is_bool(b2))
    199 		return (false);
    200 
    201 	return (prop_object_equals(b1, b2));
    202 }
    203 
    204 /*
    205  * _prop_bool_internalize --
    206  *	Parse a <true/> or <false/> and return the object created from
    207  *	the external representation.
    208  */
    209 
    210 /* ARGSUSED */
    211 bool
    212 _prop_bool_internalize(prop_stack_t stack, prop_object_t *obj,
    213     struct _prop_object_internalize_context *ctx)
    214 {
    215 	bool val;
    216 
    217 	/* No attributes, and it must be an empty element. */
    218 	if (ctx->poic_tagattr != NULL ||
    219 	    ctx->poic_is_empty_element == false)
    220 	    	return (true);
    221 
    222 	if (_PROP_TAG_MATCH(ctx, "true"))
    223 		val = true;
    224 	else {
    225 		_PROP_ASSERT(_PROP_TAG_MATCH(ctx, "false"));
    226 		val = false;
    227 	}
    228 	*obj = prop_bool_create(val);
    229 	return (true);
    230 }
    231