1 /*
2  *  Copyright (c) 2020, The OpenThread Authors.
3  *  All rights reserved.
4  *
5  *  Redistribution and use in source and binary forms, with or without
6  *  modification, are permitted provided that the following conditions are met:
7  *  1. Redistributions of source code must retain the above copyright
8  *     notice, this list of conditions and the following disclaimer.
9  *  2. Redistributions in binary form must reproduce the above copyright
10  *     notice, this list of conditions and the following disclaimer in the
11  *     documentation and/or other materials provided with the distribution.
12  *  3. Neither the name of the copyright holder nor the
13  *     names of its contributors may be used to endorse or promote products
14  *     derived from this software without specific prior written permission.
15  *
16  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20  *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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25  *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  *  POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /**
30  * @file
31  *   This file includes definitions for a bit-vector.
32  */
33 
34 #ifndef BIT_VECTOR_HPP_
35 #define BIT_VECTOR_HPP_
36 
37 #include "openthread-core-config.h"
38 
39 #include "common/code_utils.hpp"
40 #include "common/debug.hpp"
41 #include "common/encoding.hpp"
42 #include "common/equatable.hpp"
43 #include "common/numeric_limits.hpp"
44 
45 namespace ot {
46 
47 /**
48  * @addtogroup core-bit-vector
49  *
50  * @brief
51  *   This module includes definitions for bit-vector.
52  *
53  * @{
54  *
55  */
56 
57 /**
58  * Represents a bit-vector.
59  *
60  * @tparam N  Specifies the number of bits.
61  *
62  */
63 template <uint16_t N> class BitVector : public Equatable<BitVector<N>>, public Clearable<BitVector<N>>
64 {
65 public:
66     /**
67      * Indicates whether a given index is included in the mask.
68      *
69      * @param[in] aIndex  The index.
70      *
71      * @retval TRUE   If the given index is set.
72      * @retval FALSE  If the given index is clear.
73      *
74      */
Get(uint16_t aIndex) const75     bool Get(uint16_t aIndex) const
76     {
77         OT_ASSERT(aIndex < N);
78         return (mMask[aIndex / 8] & (0x80 >> (aIndex % 8))) != 0;
79     }
80 
81     /**
82      * Sets the mask of a given index.
83      *
84      * @param[in] aIndex  The index.
85      * @param[in] aValue  TRUE to set the mask, or FALSE to clear the mask.
86      *
87      */
Set(uint16_t aIndex,bool aValue)88     void Set(uint16_t aIndex, bool aValue)
89     {
90         OT_ASSERT(aIndex < N);
91 
92         if (aValue)
93         {
94             mMask[aIndex / 8] |= 0x80 >> (aIndex % 8);
95         }
96         else
97         {
98             mMask[aIndex / 8] &= ~(0x80 >> (aIndex % 8));
99         };
100     }
101 
102     /**
103      * Returns if any mask is set.
104      *
105      * @retval TRUE   If any index is set.
106      * @retval FALSE  If all indexes are clear.
107      *
108      */
HasAny(void) const109     bool HasAny(void) const
110     {
111         bool rval = false;
112 
113         for (uint8_t b : mMask)
114         {
115             if (b != 0)
116             {
117                 ExitNow(rval = true);
118             }
119         }
120 
121     exit:
122         return rval;
123     }
124 
125 private:
126     uint8_t mMask[BytesForBitSize(N)];
127 };
128 
129 /**
130  * @}
131  *
132  */
133 
134 } // namespace ot
135 
136 #endif // BIT_VECTOR_HPP_
137