1 /*
2 * Copyright (c) 2023, 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
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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 implements methods for a signed preference value and its 2-bit unsigned representation.
32 */
33
34 #include "preference.hpp"
35
36 namespace ot {
37
To2BitUint(int8_t aPrf)38 uint8_t Preference::To2BitUint(int8_t aPrf) { return (aPrf == 0) ? k2BitMedium : ((aPrf > 0) ? k2BitHigh : k2BitLow); }
39
From2BitUint(uint8_t a2BitUint)40 int8_t Preference::From2BitUint(uint8_t a2BitUint)
41 {
42 static const int8_t kPreferences[] = {
43 /* 0 (00) -> */ kMedium,
44 /* 1 (01) -> */ kHigh,
45 /* 2 (10) -> */ kMedium, // Per RFC-4191, the reserved value (10) MUST be treated as (00)
46 /* 3 (11) -> */ kLow,
47 };
48
49 return kPreferences[a2BitUint & k2BitMask];
50 }
51
IsValid(int8_t aPrf)52 bool Preference::IsValid(int8_t aPrf) { return (aPrf == kHigh) || (aPrf == kMedium) || (aPrf == kLow); }
53
ToString(int8_t aPrf)54 const char *Preference::ToString(int8_t aPrf) { return (aPrf == 0) ? "medium" : ((aPrf > 0) ? "high" : "low"); }
55
56 } // namespace ot
57