file_utils.hpp

/*
 * SPDX-FileCopyrightText: Copyright (c) 2025, NVIDIA CORPORATION.
 * SPDX-License-Identifier: Apache-2.0
 */
#pragma once
 
#include <optional>
#include <string>
 
#include <kvikio/shim/cufile_h_wrapper.hpp>
 
namespace kvikio {
class FileWrapper {
 private:
  int _fd{-1};
 
 public:
  FileWrapper(std::string const& file_path, std::string const& flags, bool o_direct, mode_t mode);
 
  FileWrapper() noexcept = default;
 
  ~FileWrapper() noexcept;
  FileWrapper(FileWrapper const&)            = delete;
  FileWrapper& operator=(FileWrapper const&) = delete;
  FileWrapper(FileWrapper&& o) noexcept;
  FileWrapper& operator=(FileWrapper&& o) noexcept;
 
  void open(std::string const& file_path, std::string const& flags, bool o_direct, mode_t mode);
 
  bool opened() const noexcept;
 
  void close() noexcept;
 
  int fd() const noexcept;
};
 
class CUFileHandleWrapper {
 private:
  CUfileHandle_t _handle{};
  bool _registered{false};
 
 public:
  CUFileHandleWrapper() noexcept = default;
  ~CUFileHandleWrapper() noexcept;
  CUFileHandleWrapper(CUFileHandleWrapper const&)            = delete;
  CUFileHandleWrapper& operator=(CUFileHandleWrapper const&) = delete;
  CUFileHandleWrapper(CUFileHandleWrapper&& o) noexcept;
  CUFileHandleWrapper& operator=(CUFileHandleWrapper&& o) noexcept;
 
  std::optional<CUfileError_t> register_handle(int fd) noexcept;
 
  bool registered() const noexcept;
 
  CUfileHandle_t handle() const noexcept;
 
  void unregister_handle() noexcept;
};
 
int open_fd_parse_flags(std::string const& flags, bool o_direct);
 
int open_fd(std::string const& file_path, std::string const& flags, bool o_direct, mode_t mode);
 
[[nodiscard]] int open_flags(int fd);
 
[[nodiscard]] std::size_t get_file_size(std::string const& file_path);
 
[[nodiscard]] std::size_t get_file_size(int file_descriptor);
 
std::pair<std::size_t, std::size_t> get_page_cache_info(std::string const& file_path);
 
std::pair<std::size_t, std::size_t> get_page_cache_info(int fd);
 
bool clear_page_cache(bool reclaim_dentries_and_inodes = true, bool clear_dirty_pages = true);
}  // namespace kvikio