| /* |
| * Copyright (c) 2018, The OpenThread Authors. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. Neither the name of the copyright holder nor the |
| * names of its contributors may be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE |
| * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** |
| * @file |
| * This file defines OpenThread String class. |
| */ |
| |
| #ifndef STRING_HPP_ |
| #define STRING_HPP_ |
| |
| #include "openthread-core-config.h" |
| |
| #include <stdarg.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| |
| #include <openthread/error.h> |
| |
| #include "common/code_utils.hpp" |
| |
| namespace ot { |
| |
| /** |
| * @addtogroup core-string |
| * |
| * @brief |
| * This module includes definitions for OpenThread String class. |
| * |
| * @{ |
| * |
| */ |
| |
| /** |
| * This function returns the number of characters that precede the terminating nullptr character. |
| * |
| * @param[in] aString A pointer to the string. |
| * @param[in] aMaxLength The maximum length in bytes. |
| * |
| * @returns The number of characters that precede the terminating nullptr character or @p aMaxLength, whichever is |
| * smaller. |
| * |
| */ |
| uint16_t StringLength(const char *aString, uint16_t aMaxLength); |
| |
| /** |
| * This class defines the base class for `String`. |
| * |
| */ |
| class StringBase |
| { |
| protected: |
| /** |
| * This method appends `printf()` style formatted data to a given character string buffer. |
| * |
| * @param[in] aBuffer A pointer to buffer containing the string. |
| * @param[in] aSize The size of the buffer (in bytes). |
| * @param[inout] aLength A reference to variable containing current length of string. On exit length is updated. |
| * @param[in] aFormat A pointer to the format string. |
| * @param[in] aArgs Arguments for the format specification. |
| * |
| * @retval OT_ERROR_NONE Updated the string successfully. |
| * @retval OT_ERROR_NO_BUFS String could not fit in the storage. |
| * @retval OT_ERROR_INVALID_ARGS Arguments do not match the format string. |
| */ |
| static otError Write(char *aBuffer, uint16_t aSize, uint16_t &aLength, const char *aFormat, va_list aArgs); |
| }; |
| |
| /** |
| * This class defines a fixed-size string. |
| * |
| */ |
| template <uint16_t SIZE> class String : private StringBase |
| { |
| public: |
| enum |
| { |
| kSize = SIZE, ///< Size (number of characters) in the buffer storage for the string. |
| }; |
| |
| /** |
| * This constructor initializes the `String` object as empty. |
| * |
| */ |
| String(void) |
| : mLength(0) |
| { |
| mBuffer[0] = 0; |
| } |
| |
| /** |
| * This constructor initializes the `String` object using `printf()` style formatted data. |
| * |
| * @param[in] aFormat A pointer to the format string. |
| * @param[in] ... Arguments for the format specification. |
| * |
| */ |
| explicit String(const char *aFormat, ...) |
| : mLength(0) |
| { |
| va_list args; |
| va_start(args, aFormat); |
| IgnoreError(Write(mBuffer, kSize, mLength, aFormat, args)); |
| va_end(args); |
| } |
| |
| /** |
| * This method clears the string. |
| * |
| */ |
| void Clear(void) |
| { |
| mBuffer[0] = 0; |
| mLength = 0; |
| } |
| |
| /** |
| * This method gets the length of the string. |
| * |
| * Similar to `strlen()` the length does not include the null character at the end of the string. |
| * |
| * @returns The string length. |
| * |
| */ |
| uint16_t GetLength(void) const { return mLength; } |
| |
| /** |
| * This method returns the size (number of chars) in the buffer storage for the string. |
| * |
| * @returns The size of the buffer storage for the string. |
| * |
| */ |
| uint16_t GetSize(void) const { return kSize; } |
| |
| /** |
| * This method returns the string as a null-terminated C string. |
| * |
| * @returns The null-terminated C string. |
| * |
| */ |
| const char *AsCString(void) const { return mBuffer; } |
| |
| /** |
| * This method sets the string using `printf()` style formatted data. |
| * |
| * @param[in] aFormat A pointer to the format string. |
| * @param[in] ... Arguments for the format specification. |
| * |
| * @retval OT_ERROR_NONE Updated the string successfully. |
| * @retval OT_ERROR_NO_BUFS String could not fit in the storage. |
| * @retval OT_ERROR_INVALID_ARGS Arguments do not match the format string. |
| * |
| */ |
| otError Set(const char *aFormat, ...) |
| { |
| va_list args; |
| otError error; |
| |
| va_start(args, aFormat); |
| mLength = 0; |
| error = Write(mBuffer, kSize, mLength, aFormat, args); |
| va_end(args); |
| |
| return error; |
| } |
| |
| /** |
| * This method appends `printf()` style formatted data to the `String` object. |
| * |
| * @param[in] aFormat A pointer to the format string. |
| * @param[in] ... Arguments for the format specification. |
| * |
| * @retval OT_ERROR_NONE Updated the string successfully. |
| * @retval OT_ERROR_NO_BUFS String could not fit in the storage. |
| * @retval OT_ERROR_INVALID_ARGS Arguments do not match the format string. |
| * |
| */ |
| otError Append(const char *aFormat, ...) |
| { |
| va_list args; |
| otError error; |
| |
| va_start(args, aFormat); |
| error = Write(mBuffer, kSize, mLength, aFormat, args); |
| va_end(args); |
| |
| return error; |
| } |
| |
| /** |
| * This method appends an array of bytes in hex representation (using "%02x" style) to the `String` object. |
| * |
| * @param[in] aBytes A pointer to buffer containing the bytes to append. |
| * @param[in] aLength The length of @p aBytes buffer (in bytes). |
| * |
| * @retval OT_ERROR_NONE Updated the string successfully. |
| * @retval OT_ERROR_NO_BUFS String could not fit in the storage. |
| * |
| */ |
| otError AppendHexBytes(const uint8_t *aBytes, uint16_t aLength) |
| { |
| otError error = OT_ERROR_NONE; |
| |
| while (aLength--) |
| { |
| SuccessOrExit(error = Append("%02x", *aBytes++)); |
| } |
| |
| exit: |
| return error; |
| } |
| |
| private: |
| uint16_t mLength; |
| char mBuffer[kSize]; |
| }; |
| |
| /** |
| * @} |
| * |
| */ |
| |
| } // namespace ot |
| |
| #endif // STRING_HPP_ |