src/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 _PROP_MUTEX_DECL_STATIC(_prop_bool_initialized_mutex)
  44 static bool     _prop_bool_initialized;
  45
  46 static _prop_object_free_rv_t
  47                 _prop_bool_free(prop_stack_t, prop_object_t *);
  48 static bool     _prop_bool_externalize(
  49                                 struct _prop_object_externalize_context *,
  50                                 void *);
  51 static _prop_object_equals_rv_t
  52                 _prop_bool_equals(prop_object_t, prop_object_t,
  53                                   void **, void **,
  54                                   prop_object_t *, prop_object_t *);
  55
  56 static const struct _prop_object_type _prop_object_type_bool = {
  57         .pot_type       =       PROP_TYPE_BOOL,
  58         .pot_free       =       _prop_bool_free,
  59         .pot_extern     =       _prop_bool_externalize,
  60         .pot_equals     =       _prop_bool_equals,
  61 };
  62
  63 #define prop_object_is_bool(x)          \
  64         ((x) != NULL && (x)->pb_obj.po_type == &_prop_object_type_bool)
  65
  66 /* ARGSUSED */
  67 static _prop_object_free_rv_t
  68 _prop_bool_free(prop_stack_t stack, prop_object_t *obj)
  69 {
  70         /*
  71          * This should never happen as we "leak" our initial reference
  72          * count.
  73          */
  74
  75         /* XXX forced assertion failure? */
  76         return (_PROP_OBJECT_FREE_DONE);
  77 }
  78
  79 static bool
  80 _prop_bool_externalize(struct _prop_object_externalize_context *ctx,
  81                        void *v)
  82 {
  83         prop_bool_t pb = v;
  84
  85         return (_prop_object_externalize_empty_tag(ctx,
  86             pb->pb_value ? "true" : "false"));
  87 }
  88
  89 /* ARGSUSED */
  90 static _prop_object_equals_rv_t
  91 _prop_bool_equals(prop_object_t v1, prop_object_t v2,
  92     void **stored_pointer1, void **stored_pointer2,
  93     prop_object_t *next_obj1, prop_object_t *next_obj2)
  94 {
  95         prop_bool_t b1 = v1;
  96         prop_bool_t b2 = v2;
  97
  98         if (! (prop_object_is_bool(b1) &&
  99                prop_object_is_bool(b2)))
 100                 return (_PROP_OBJECT_EQUALS_FALSE);
 101
 102         /*
 103          * Since we only ever allocate one true and one false,
 104          * save ourselves a couple of memory operations.
 105          */
 106         if (b1 == b2)
 107                 return (_PROP_OBJECT_EQUALS_TRUE);
 108         else
 109                 return (_PROP_OBJECT_EQUALS_FALSE);
 110 }
 111
 112 static prop_bool_t
 113 _prop_bool_alloc(bool val)
 114 {
 115         prop_bool_t pb;
 116
 117         if (! _prop_bool_initialized) {
 118                 _PROP_MUTEX_LOCK(_prop_bool_initialized_mutex);
 119                 if (! _prop_bool_initialized) {
 120                         _prop_object_init(&_prop_bool_true.pb_obj,
 121                                           &_prop_object_type_bool);
 122                         _prop_bool_true.pb_value = true;
 123
 124                         _prop_object_init(&_prop_bool_false.pb_obj,
 125                                           &_prop_object_type_bool);
 126                         _prop_bool_false.pb_value = false;
 127
 128                         _prop_bool_initialized = true;
 129                 }
 130                 _PROP_MUTEX_UNLOCK(_prop_bool_initialized_mutex);
 131         }
 132
 133         pb = val ? &_prop_bool_true : &_prop_bool_false;
 134         prop_object_retain(pb);
 135
 136         return (pb);
 137 }
 138
 139 /*
 140  * prop_bool_create --
 141  *      Create a prop_bool_t and initialize it with the
 142  *      provided boolean value.
 143  */
 144 prop_bool_t
 145 prop_bool_create(bool val)
 146 {
 147
 148         return (_prop_bool_alloc(val));
 149 }
 150
 151 /*
 152  * prop_bool_copy --
 153  *      Copy a prop_bool_t.
 154  */
 155 prop_bool_t
 156 prop_bool_copy(prop_bool_t opb)
 157 {
 158
 159         if (! prop_object_is_bool(opb))
 160                 return (NULL);
 161
 162         /*
 163          * Because we only ever allocate one true and one false, this
 164          * can be reduced to a simple retain operation.
 165          */
 166         prop_object_retain(opb);
 167         return (opb);
 168 }
 169
 170 /*
 171  * prop_bool_true --
 172  *      Get the value of a prop_bool_t.
 173  */
 174 bool
 175 prop_bool_true(prop_bool_t pb)
 176 {
 177
 178         if (! prop_object_is_bool(pb))
 179                 return (false);
 180
 181         return (pb->pb_value);
 182 }
 183
 184 /*
 185  * prop_bool_equals --
 186  *      Return true if the boolean values are equivalent.
 187  */
 188 bool
 189 prop_bool_equals(prop_bool_t b1, prop_bool_t b2)
 190 {
 191         if (!prop_object_is_bool(b1) || !prop_object_is_bool(b2))
 192                 return (false);
 193
 194         return (prop_object_equals(b1, b2));
 195 }
 196
 197 /*
 198  * _prop_bool_internalize --
 199  *      Parse a <true/> or <false/> and return the object created from
 200  *      the external representation.
 201  */
 202
 203 /* ARGSUSED */
 204 bool
 205 _prop_bool_internalize(prop_stack_t stack, prop_object_t *obj,
 206     struct _prop_object_internalize_context *ctx)
 207 {
 208         bool val;
 209
 210         /* No attributes, and it must be an empty element. */
 211         if (ctx->poic_tagattr != NULL ||
 212             ctx->poic_is_empty_element == false)
 213                 return (true);
 214
 215         if (_PROP_TAG_MATCH(ctx, "true"))
 216                 val = true;
 217         else {
 218                 _PROP_ASSERT(_PROP_TAG_MATCH(ctx, "false"));
 219                 val = false;
 220         }
 221         *obj = prop_bool_create(val);
 222         return (true);
 223 }