compat_mode.hpp

/*
 * Copyright (c) 2025, NVIDIA CORPORATION.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * https://apache.ac.cn/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include <cstdint>
#include <string>

#include <kvikio/file_utils.hpp>

namespace kvikio {
enum class CompatMode : uint8_t {
 OFF,
 ON,
 AUTO,
};

namespace detail {
CompatMode parse_compat_mode_str(std::string_view compat_mode_str);

} // namespace detail

// Forward declaration.
class FileHandle;

class CompatModeManager {
 private
 CompatMode _compat_mode_requested{CompatMode::AUTO};
 bool _is_compat_mode_preferred{true};
 bool _is_compat_mode_preferred_for_async{true};

 public
 CompatModeManager() noexcept = default;

 CompatModeManager(std::string const& file_path,
 std::string const& flags,
 mode_t mode,
 CompatMode compat_mode_requested,
 FileHandle* file_handle);

 ~CompatModeManager() noexcept = default;
 CompatModeManager(const CompatModeManager&) = default;
 CompatModeManager& operator=(const CompatModeManager&) = default;
 CompatModeManager(CompatModeManager&&) noexcept = default;
 CompatModeManager& operator=(CompatModeManager&&) noexcept = default;

 CompatMode infer_compat_mode_if_auto(CompatMode compat_mode) noexcept;

 bool is_compat_mode_preferred(CompatMode compat_mode) noexcept;

 bool is_compat_mode_preferred() const noexcept;

 bool is_compat_mode_preferred_for_async() const noexcept;

 CompatMode compat_mode_requested() const noexcept;

 void validate_compat_mode_for_async() const;
};

} // namespace kvikio