src/common/file-descriptor.hpp

   1 /*
   2  * Copyright (C) 2023 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7
   8 #ifndef LTTNG_FILE_DESCRIPTOR_HPP
   9 #define LTTNG_FILE_DESCRIPTOR_HPP
  10
  11 #include <cstddef>
  12
  13 namespace lttng {
  14
  15 /* RAII wrapper around a UNIX file descriptor. */
  16 class file_descriptor {
  17 public:
  18         file_descriptor() noexcept = default;
  19
  20         explicit file_descriptor(int raw_fd) noexcept;
  21         file_descriptor(const file_descriptor&) = delete;
  22         file_descriptor& operator=(const file_descriptor&) = delete;
  23
  24         file_descriptor(file_descriptor&& other) noexcept;
  25
  26         file_descriptor& operator=(file_descriptor&& other) noexcept;
  27
  28         ~file_descriptor() noexcept;
  29
  30         /*
  31          * Read `size` bytes from the underlying file descriptor, assuming
  32          * raw_fd behaves as a blocking device.
  33          *
  34          * Throws an exception if the requested amount of bytes couldn't be read.
  35          */
  36         void read(void *buffer, std::size_t size);
  37         /*
  38          * Write `size` bytes to the underlying file descriptor, assuming
  39          * raw_fd behaves as a blocking device.
  40          *
  41          * Throws an exception if the requested amount of bytes couldn't be written.
  42          */
  43         void write(const void *buffer, std::size_t size);
  44
  45         int fd() const noexcept;
  46
  47 protected:
  48         void _cleanup() noexcept;
  49
  50 private:
  51         int _raw_fd = -1;
  52 };
  53
  54 } /* namespace lttng */
  55
  56 #endif /* LTTNG_FILE_DESCRIPTOR_HPP */