1 /*
2 * Copyright (c) 2024, 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 helper method for an offset range.
32 */
33
34 #include "offset_range.hpp"
35
36 #include "common/code_utils.hpp"
37 #include "common/message.hpp"
38 #include "common/num_utils.hpp"
39 #include "common/numeric_limits.hpp"
40
41 namespace ot {
42
Init(uint16_t aOffset,uint16_t aLength)43 void OffsetRange::Init(uint16_t aOffset, uint16_t aLength)
44 {
45 uint16_t maxLength = NumericLimits<uint16_t>::kMax - aOffset;
46
47 mOffset = aOffset;
48 mLength = Min(aLength, maxLength);
49 }
50
InitFromRange(uint16_t aStartOffset,uint16_t aEndOffset)51 void OffsetRange::InitFromRange(uint16_t aStartOffset, uint16_t aEndOffset)
52 {
53 Init(aStartOffset, Max(aStartOffset, aEndOffset) - aStartOffset);
54 }
55
InitFromMessageOffsetToEnd(const Message & aMessage)56 void OffsetRange::InitFromMessageOffsetToEnd(const Message &aMessage)
57 {
58 InitFromRange(aMessage.GetOffset(), aMessage.GetLength());
59 }
60
InitFromMessageFullLength(const Message & aMessage)61 void OffsetRange::InitFromMessageFullLength(const Message &aMessage) { Init(0, aMessage.GetLength()); }
62
AdvanceOffset(uint32_t aLength)63 void OffsetRange::AdvanceOffset(uint32_t aLength)
64 {
65 uint16_t length = static_cast<uint16_t>(Min<uint32_t>(aLength, mLength));
66
67 mOffset += length;
68 mLength -= length;
69 }
70
ShrinkLength(uint16_t aLength)71 void OffsetRange::ShrinkLength(uint16_t aLength) { mLength = Min(mLength, aLength); }
72
73 } // namespace ot
74
