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
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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 
44 namespace ot {
45 
46 /**
47  * @addtogroup core-bit-vector
48  *
49  * @brief
50  *   This module includes definitions for bit-vector.
51  *
52  * @{
53  *
54  */
55 
56 /**
57  * This class represents a bit-vector.
58  *
59  * @tparam N  Specifies the number of bits.
60  *
61  */
62 template <uint16_t N> class BitVector : public Equatable<BitVector<N>>, public Clearable<BitVector<N>>
63 {
64 public:
65     /**
66      * This method indicates whether a given index is included in the mask.
67      *
68      * @param[in] aIndex  The index.
69      *
70      * @retval TRUE   If the given index is set.
71      * @retval FALSE  If the given index is clear.
72      *
73      */
Get(uint16_t aIndex) const74     bool Get(uint16_t aIndex) const
75     {
76         OT_ASSERT(aIndex < N);
77         return (mMask[aIndex / 8] & (0x80 >> (aIndex % 8))) != 0;
78     }
79 
80     /**
81      * This method sets the mask of a given index.
82      *
83      * @param[in] aIndex  The index.
84      * @param[in] aValue  TRUE to set the mask, or FALSE to clear the mask.
85      *
86      */
Set(uint16_t aIndex,bool aValue)87     void Set(uint16_t aIndex, bool aValue)
88     {
89         OT_ASSERT(aIndex < N);
90 
91         if (aValue)
92         {
93             mMask[aIndex / 8] |= 0x80 >> (aIndex % 8);
94         }
95         else
96         {
97             mMask[aIndex / 8] &= ~(0x80 >> (aIndex % 8));
98         };
99     }
100 
101     /**
102      * This method returns if any mask is set.
103      *
104      * @retval TRUE   If any index is set.
105      * @retval FALSE  If all indexes are clear.
106      *
107      */
HasAny(void) const108     bool HasAny(void) const
109     {
110         bool rval = false;
111 
112         for (uint8_t b : mMask)
113         {
114             if (b != 0)
115             {
116                 ExitNow(rval = true);
117             }
118         }
119 
120     exit:
121         return rval;
122     }
123 
124 private:
125     uint8_t mMask[BitVectorBytes(N)];
126 };
127 
128 /**
129  * @}
130  *
131  */
132 
133 } // namespace ot
134 
135 #endif // BIT_VECTOR_HPP_
136