1 /* 2 * Copyright (c) 2021, 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 includes definitions for `Heap::Data` (heap allocated data). 32 */ 33 34 #ifndef HEAP_DATA_HPP_ 35 #define HEAP_DATA_HPP_ 36 37 #include "openthread-core-config.h" 38 39 #include "common/data.hpp" 40 #include "common/heap.hpp" 41 #include "common/message.hpp" 42 43 namespace ot { 44 namespace Heap { 45 46 /** 47 * Represents a heap allocated data. 48 * 49 */ 50 class Data 51 { 52 public: 53 /** 54 * Initializes the `Heap::Data` as empty. 55 * 56 */ Data(void)57 Data(void) { mData.Init(nullptr, 0); } 58 59 /** 60 * This is the move constructor for `Heap::Data`. 61 * 62 * `Heap::Data` is non-copyable (copy constructor is deleted) but move constructor is provided to allow it to to be 63 * used as return type (return by value) from functions/methods (which will then use move semantics). 64 * 65 * @param[in] aData An rvalue reference to another `Heap::Data` to move from. 66 * 67 */ Data(Data && aData)68 Data(Data &&aData) { TakeFrom(aData); } 69 70 /** 71 * This is the destructor for `Heap::Data` object. 72 * 73 */ ~Data(void)74 ~Data(void) { Free(); } 75 76 /** 77 * Indicates whether or not the `Heap::Data` is null (i.e., it was never successfully set or it was 78 * freed). 79 * 80 * @retval TRUE The `Heap::Data` is null. 81 * @retval FALSE The `Heap::Data` is not null. 82 * 83 */ IsNull(void) const84 bool IsNull(void) const { return (mData.GetBytes() == nullptr); } 85 86 /** 87 * Returns a pointer to the `Heap::Data` bytes buffer. 88 * 89 * @returns A pointer to data buffer or `nullptr` if the `Heap::Data` is null (never set or freed). 90 * 91 */ GetBytes(void) const92 const uint8_t *GetBytes(void) const { return mData.GetBytes(); } 93 94 /** 95 * Returns the `Heap::Data` length. 96 * 97 * @returns The data length (number of bytes) or zero if the `HeapData` is null. 98 * 99 */ GetLength(void) const100 uint16_t GetLength(void) const { return mData.GetLength(); } 101 102 /** 103 * Sets the `Heap::Data` from the content of a given buffer. 104 * 105 * @param[in] aBuffer The buffer to copy bytes from. 106 * @param[in] aLength The buffer length (number of bytes). 107 * 108 * @retval kErrorNone Successfully set the `Heap::Data`. 109 * @retval kErrorNoBufs Failed to allocate buffer. 110 * 111 */ 112 Error SetFrom(const uint8_t *aBuffer, uint16_t aLength); 113 114 /** 115 * Sets the `Heap::Data` from the content of a given message. 116 * 117 * The bytes are copied from current offset in @p aMessage till the end of the message. 118 * 119 * @param[in] aMessage The message to copy bytes from (starting from offset till the end of message). 120 * 121 * @retval kErrorNone Successfully set the `Heap::Data`. 122 * @retval kErrorNoBufs Failed to allocate buffer. 123 * 124 */ 125 Error SetFrom(const Message &aMessage); 126 127 /** 128 * Sets the `Heap::Data` from the content of a given message read at a given offset up to a given 129 * length. 130 * 131 * @param[in] aMessage The message to read and copy bytes from. 132 * @param[in] aOffset The offset into the message to start reading the bytes from. 133 * @param[in] aLength The number of bytes to read from message. If @p aMessage contains fewer bytes than 134 * requested, then `Heap::Data` is cleared and this method returns `kErrorParse`. 135 * 136 * @retval kErrorNone Successfully set the `Heap::Data`. 137 * @retval kErrorNoBufs Failed to allocate buffer. 138 * @retval kErrorParse Not enough bytes in @p aMessage to read the requested @p aLength bytes. 139 * 140 */ 141 Error SetFrom(const Message &aMessage, uint16_t aOffset, uint16_t aLength); 142 143 /** 144 * Sets the `Heap::Data` from another one (move semantics). 145 * 146 * @param[in] aData The other `Heap::Data` to set from (rvalue reference). 147 * 148 */ 149 void SetFrom(Data &&aData); 150 151 /** 152 * Appends the bytes from `Heap::Data` to a given message. 153 * 154 * @param[in] aMessage The message to append the bytes into. 155 * 156 * @retval kErrorNone Successfully copied the bytes from `Heap::Data` into @p aMessage. 157 * @retval kErrorNoBufs Failed to allocate buffer. 158 * 159 */ CopyBytesTo(Message & aMessage) const160 Error CopyBytesTo(Message &aMessage) const { return aMessage.AppendBytes(mData.GetBytes(), mData.GetLength()); } 161 162 /** 163 * Copies the bytes from `Heap::Data` into a given buffer. 164 * 165 * It is up to the caller to ensure that @p aBuffer has enough space for the current data length. 166 * 167 * @param[in] aBuffer A pointer to buffer to copy the bytes into. 168 * 169 */ CopyBytesTo(uint8_t * aBuffer) const170 void CopyBytesTo(uint8_t *aBuffer) const { return mData.CopyBytesTo(aBuffer); } 171 172 /** 173 * Compares the `Data` content with the bytes from a given buffer. 174 * 175 * @param[in] aBuffer A pointer to a buffer to compare with the data. 176 * @param[in] aLength The length of @p aBuffer. 177 * 178 * @retval TRUE The `Data` content matches the bytes in @p aBuffer. 179 * @retval FALSE The `Data` content does not match the byes in @p aBuffer. 180 * 181 */ 182 bool Matches(const uint8_t *aBuffer, uint16_t aLength) const; 183 184 /** 185 * Overloads operator `==` to compare the `Data` content with the content from another one. 186 * 187 * @param[in] aOtherData The other `Data` to compare with. 188 * 189 * @retval TRUE The two `Data` instances have matching content (same length and same bytes). 190 * @retval FALSE The two `Data` instances do not have matching content. 191 * 192 */ operator ==(const Data & aOtherData) const193 bool operator==(const Data &aOtherData) const { return mData == aOtherData.mData; } 194 195 /** 196 * Frees any buffer allocated by the `Heap::Data`. 197 * 198 * The `Heap::Data` destructor will automatically call `Free()`. This method allows caller to free the buffer 199 * explicitly. 200 * 201 */ 202 void Free(void); 203 204 Data(const Data &) = delete; 205 Data &operator=(const Data &) = delete; 206 207 private: 208 Error UpdateBuffer(uint16_t aNewLength); 209 void TakeFrom(Data &aData); 210 211 MutableData<kWithUint16Length> mData; 212 }; 213 214 } // namespace Heap 215 } // namespace ot 216 217 #endif // HEAP_DATA_HPP_ 218
