serenity/Kernel/Devices/NullDevice.h
2021-08-03 10:36:48 +02:00

36 lines
1.1 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <Kernel/Devices/CharacterDevice.h>
namespace Kernel {
class NullDevice final : public CharacterDevice {
AK_MAKE_ETERNAL
public:
NullDevice();
virtual ~NullDevice() override;
static void initialize();
static NullDevice& the();
// ^Device
virtual mode_t required_mode() const override { return 0666; }
virtual String device_name() const override { return "null"; }
private:
// ^CharacterDevice
virtual KResultOr<size_t> read(FileDescription&, u64, UserOrKernelBuffer&, size_t) override;
virtual KResultOr<size_t> write(FileDescription&, u64, const UserOrKernelBuffer&, size_t) override;
virtual bool can_write(const FileDescription&, size_t) const override { return true; }
virtual bool can_read(const FileDescription&, size_t) const override;
virtual StringView class_name() const override { return "NullDevice"; }
virtual bool is_seekable() const override { return true; }
};
}