src/cpp-common/bt2c/read-fixed-len-int.hpp

   1 /*
   2  * Copyright (c) 2022 Philippe Proulx <pproulx@efficios.com>
   3  *
   4  * SPDX-License-Identifier: MIT
   5  */
   6
   7 #ifndef BABELTRACE_CPP_COMMON_BT2C_READ_FIXED_LEN_INT_HPP
   8 #define BABELTRACE_CPP_COMMON_BT2C_READ_FIXED_LEN_INT_HPP
   9
  10 #include <cstdint>
  11 #include <cstring>
  12 #include <type_traits>
  13
  14 #include "endian.hpp"
  15
  16 namespace bt2c {
  17
  18 /*
  19  * Reads a fixed-length integer of unknown byte order into a value of integral
  20  * type `IntT` from the buffer `buf` and returns it.
  21  */
  22 template <typename IntT>
  23 IntT readFixedLenInt(const std::uint8_t * const buf)
  24 {
  25     static_assert(std::is_integral<IntT>::value, "`IntT` is an integral type.");
  26
  27     IntT val;
  28
  29     std::memcpy(&val, buf, sizeof(val));
  30     return val;
  31 }
  32
  33 /*
  34  * Reads a fixed-length little-endian integer into a value of integral
  35  * type `IntT` from the buffer `buf` and returns it.
  36  */
  37 template <typename IntT>
  38 IntT readFixedLenIntLe(const std::uint8_t * const buf)
  39 {
  40     return bt2c::littleEndianToNative(readFixedLenInt<IntT>(buf));
  41 }
  42
  43 /*
  44  * Reads a fixed-length big-endian integer into a value of integral
  45  * type `IntT` from the buffer `buf` and returns it.
  46  */
  47 template <typename IntT>
  48 IntT readFixedLenIntBe(const std::uint8_t * const buf)
  49 {
  50     return bt2c::bigEndianToNative(readFixedLenInt<IntT>(buf));
  51 }
  52
  53 } /* namespace bt2c */
  54
  55 #endif /* BABELTRACE_CPP_COMMON_BT2C_READ_FIXED_LEN_INT_HPP */