mirror of
https://github.com/TomHarte/CLK.git
synced 2024-08-17 07:29:04 +00:00
91 lines
2.6 KiB
C++
91 lines
2.6 KiB
C++
//
|
|
// Disk.hpp
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 10/07/2016.
|
|
// Copyright © 2016 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#ifndef Disk_hpp
|
|
#define Disk_hpp
|
|
|
|
#include <memory>
|
|
#include "../Storage.hpp"
|
|
|
|
namespace Storage {
|
|
namespace Disk {
|
|
|
|
/*!
|
|
Models a single track on a disk as a series of events, each event being of arbitrary length
|
|
and resulting in either a flux transition or the sensing of an index hole.
|
|
|
|
Subclasses should implement @c get_next_event.
|
|
*/
|
|
class Track {
|
|
public:
|
|
/*!
|
|
Describes a detectable track event — either a flux transition or the passing of the index hole,
|
|
along with the length of time between the previous event and its occurance.
|
|
|
|
The sum of all lengths of time across an entire track should be 1 — if an event is said to be
|
|
1/3 away then that means 1/3 of a rotation.
|
|
*/
|
|
struct Event {
|
|
enum {
|
|
IndexHole, FluxTransition
|
|
} type;
|
|
Time length;
|
|
};
|
|
|
|
/*!
|
|
@returns the next event that will be detected during rotation of this disk.
|
|
*/
|
|
virtual Event get_next_event() = 0;
|
|
|
|
/*!
|
|
Jumps to the event latest offset that is less than or equal to the input time.
|
|
|
|
@returns the time jumped to.
|
|
*/
|
|
virtual Time seek_to(Time time_since_index_hole) = 0;
|
|
};
|
|
|
|
/*!
|
|
Models a disk as a collection of tracks, providing a range of possible track positions and allowing
|
|
a point sampling of the track beneath any of those positions (if any).
|
|
|
|
The intention is not that tracks necessarily be evenly spaced; a head_position_count of 3 wih track
|
|
A appearing in positions 0 and 1, and track B appearing in position 2 is an appropriate use of this API
|
|
if it matches the media.
|
|
|
|
The track returned is point sampled only; if a particular disk drive has a sufficiently large head to
|
|
pick up multiple tracks at once then the drive responsible for asking for multiple tracks and for
|
|
merging the results.
|
|
*/
|
|
class Disk {
|
|
public:
|
|
|
|
/*!
|
|
Returns the number of discrete positions that this disk uses to model its complete surface area.
|
|
|
|
This is not necessarily a track count. There is no implicit guarantee that every position will
|
|
return a distinct track, or — if the media is holeless — will return any track at all.
|
|
*/
|
|
virtual unsigned int get_head_position_count() = 0;
|
|
|
|
/*!
|
|
Returns the number of heads (and, therefore, impliedly surfaces) available on this disk.
|
|
*/
|
|
virtual unsigned int get_head_count() { return 1; }
|
|
|
|
/*!
|
|
Returns the @c Track at @c position if there are any detectable events there; returns @c nullptr otherwise.
|
|
*/
|
|
virtual std::shared_ptr<Track> get_track_at_position(unsigned int head, unsigned int position) = 0;
|
|
};
|
|
|
|
}
|
|
}
|
|
|
|
#endif /* Disk_hpp */
|