common/lib/libprop/prop_bool.c

   1 /*      $NetBSD: prop_bool.c,v 1.16 2008/08/03 04:00:12 thorpej 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 static _prop_object_free_rv_t
  44                 _prop_bool_free(prop_stack_t, prop_object_t *);
  45 static bool     _prop_bool_externalize(
  46                                 struct _prop_object_externalize_context *,
  47                                 void *);
  48 static _prop_object_equals_rv_t
  49                 _prop_bool_equals(prop_object_t, prop_object_t,
  50                                   void **, void **,
  51                                   prop_object_t *, prop_object_t *);
  52
  53 static const struct _prop_object_type _prop_object_type_bool = {
  54         .pot_type       =       PROP_TYPE_BOOL,
  55         .pot_free       =       _prop_bool_free,
  56         .pot_extern     =       _prop_bool_externalize,
  57         .pot_equals     =       _prop_bool_equals,
  58 };
  59
  60 #define prop_object_is_bool(x)          \
  61         ((x) != NULL && (x)->pb_obj.po_type == &_prop_object_type_bool)
  62
  63 /* ARGSUSED */
  64 static _prop_object_free_rv_t
  65 _prop_bool_free(prop_stack_t stack, prop_object_t *obj)
  66 {
  67         /*
  68          * This should never happen as we "leak" our initial reference
  69          * count.
  70          */
  71
  72         /* XXX forced assertion failure? */
  73         return (_PROP_OBJECT_FREE_DONE);
  74 }
  75
  76 static bool
  77 _prop_bool_externalize(struct _prop_object_externalize_context *ctx,
  78                        void *v)
  79 {
  80         prop_bool_t pb = v;
  81
  82         return (_prop_object_externalize_empty_tag(ctx,
  83             pb->pb_value ? "true" : "false"));
  84 }
  85
  86 /* ARGSUSED */
  87 static _prop_object_equals_rv_t
  88 _prop_bool_equals(prop_object_t v1, prop_object_t v2,
  89     void **stored_pointer1, void **stored_pointer2,
  90     prop_object_t *next_obj1, prop_object_t *next_obj2)
  91 {
  92         prop_bool_t b1 = v1;
  93         prop_bool_t b2 = v2;
  94
  95         if (! (prop_object_is_bool(b1) &&
  96                prop_object_is_bool(b2)))
  97                 return (_PROP_OBJECT_EQUALS_FALSE);
  98
  99         /*
 100          * Since we only ever allocate one true and one false,
 101          * save ourselves a couple of memory operations.
 102          */
 103         if (b1 == b2)
 104                 return (_PROP_OBJECT_EQUALS_TRUE);
 105         else
 106                 return (_PROP_OBJECT_EQUALS_FALSE);
 107 }
 108
 109 _PROP_ONCE_DECL(_prop_bool_init_once)
 110
 111 static int
 112 _prop_bool_init(void)
 113 {
 114
 115         _prop_object_init(&_prop_bool_true.pb_obj,
 116             &_prop_object_type_bool);
 117         _prop_bool_true.pb_value = true;
 118
 119         _prop_object_init(&_prop_bool_false.pb_obj,
 120             &_prop_object_type_bool);
 121         _prop_bool_false.pb_value = false;
 122
 123         return 0;
 124 }
 125
 126 static prop_bool_t
 127 _prop_bool_alloc(bool val)
 128 {
 129         prop_bool_t pb;
 130
 131         _PROP_ONCE_RUN(_prop_bool_init_once, _prop_bool_init);
 132         pb = val ? &_prop_bool_true : &_prop_bool_false;
 133         prop_object_retain(pb);
 134
 135         return (pb);
 136 }
 137
 138 /*
 139  * prop_bool_create --
 140  *      Create a prop_bool_t and initialize it with the
 141  *      provided boolean value.
 142  */
 143 prop_bool_t
 144 prop_bool_create(bool val)
 145 {
 146
 147         return (_prop_bool_alloc(val));
 148 }
 149
 150 /*
 151  * prop_bool_copy --
 152  *      Copy a prop_bool_t.
 153  */
 154 prop_bool_t
 155 prop_bool_copy(prop_bool_t opb)
 156 {
 157
 158         if (! prop_object_is_bool(opb))
 159                 return (NULL);
 160
 161         /*
 162          * Because we only ever allocate one true and one false, this
 163          * can be reduced to a simple retain operation.
 164          */
 165         prop_object_retain(opb);
 166         return (opb);
 167 }
 168
 169 /*
 170  * prop_bool_true --
 171  *      Get the value of a prop_bool_t.
 172  */
 173 bool
 174 prop_bool_true(prop_bool_t pb)
 175 {
 176
 177         if (! prop_object_is_bool(pb))
 178                 return (false);
 179
 180         return (pb->pb_value);
 181 }
 182
 183 /*
 184  * prop_bool_equals --
 185  *      Return true if the boolean values are equivalent.
 186  */
 187 bool
 188 prop_bool_equals(prop_bool_t b1, prop_bool_t b2)
 189 {
 190         if (!prop_object_is_bool(b1) || !prop_object_is_bool(b2))
 191                 return (false);
 192
 193         return (prop_object_equals(b1, b2));
 194 }
 195
 196 /*
 197  * _prop_bool_internalize --
 198  *      Parse a <true/> or <false/> and return the object created from
 199  *      the external representation.
 200  */
 201
 202 /* ARGSUSED */
 203 bool
 204 _prop_bool_internalize(prop_stack_t stack, prop_object_t *obj,
 205     struct _prop_object_internalize_context *ctx)
 206 {
 207         bool val;
 208
 209         /* No attributes, and it must be an empty element. */
 210         if (ctx->poic_tagattr != NULL ||
 211             ctx->poic_is_empty_element == false)
 212                 return (true);
 213
 214         if (_PROP_TAG_MATCH(ctx, "true"))
 215                 val = true;
 216         else {
 217                 _PROP_ASSERT(_PROP_TAG_MATCH(ctx, "false"));
 218                 val = false;
 219         }
 220         *obj = prop_bool_create(val);
 221         return (true);
 222 }