ladybird/Kernel/Devices/Device.h
Sergey Bugaev acccf9ccda Kernel: Move device lookup to Device class itself
Previously, VFS stored a list of all devices, and devices had to
register and unregister themselves with it. This cleans up things
a bit.
2019-08-18 15:59:59 +02:00

48 lines
1.3 KiB
C++

#pragma once
// Device is the base class of everything that lives in the /dev directory.
//
// To expose a Device to the filesystem, simply pass two unique numbers to the constructor,
// and then mknod a file in /dev with those numbers.
//
// There are two main subclasses:
// - BlockDevice (random access)
// - CharacterDevice (sequential)
#include <AK/Function.h>
#include <AK/HashMap.h>
#include <Kernel/FileSystem/File.h>
#include <Kernel/UnixTypes.h>
class Device : public File {
public:
virtual ~Device() override;
unsigned major() const { return m_major; }
unsigned minor() const { return m_minor; }
virtual String absolute_path(const FileDescription&) const override;
virtual String absolute_path() const;
uid_t uid() const { return m_uid; }
uid_t gid() const { return m_gid; }
virtual bool is_device() const override { return true; }
virtual bool is_disk_device() const { return false; }
static void for_each(Function<void(Device&)>);
static Device* get_device(unsigned major, unsigned minor);
protected:
Device(unsigned major, unsigned minor);
void set_uid(uid_t uid) { m_uid = uid; }
void set_gid(gid_t gid) { m_gid = gid; }
static HashMap<u32, Device*>& all_devices();
private:
unsigned m_major { 0 };
unsigned m_minor { 0 };
uid_t m_uid { 0 };
gid_t m_gid { 0 };
};