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CLK/Storage/Disk/Formats/SSD.cpp

82 lines
1.9 KiB
C++

//
// SSD.cpp
// Clock Signal
//
// Created by Thomas Harte on 18/09/2016.
// Copyright © 2016 Thomas Harte. All rights reserved.
//
#include "SSD.hpp"
#include <sys/stat.h>
#include "../Encodings/MFM.hpp"
using namespace Storage::Disk;
SSD::SSD(const char *file_name) : _file(nullptr)
{
struct stat file_stats;
stat(file_name, &file_stats);
// very loose validation: the file needs to be a multiple of 256 bytes
// and not ungainly large
if(file_stats.st_size & 255) throw ErrorNotSSD;
if(file_stats.st_size < 512) throw ErrorNotSSD;
if(file_stats.st_size > 800*256) throw ErrorNotSSD;
_file = fopen(file_name, "rb");
if(!_file) throw ErrorCantOpen;
// this has two heads if the suffix is .dsd, one if it's .ssd
_head_count = (tolower(file_name[strlen(file_name) - 3]) == 'd') ? 2 : 1;
_track_count = (unsigned int)(file_stats.st_size / (256 * 10));
if(_track_count < 40) _track_count = 40;
else if(_track_count < 80) _track_count = 80;
}
SSD::~SSD()
{
if(_file) fclose(_file);
}
unsigned int SSD::get_head_position_count()
{
return _track_count;
}
unsigned int SSD::get_head_count()
{
return _head_count;
}
std::shared_ptr<Track> SSD::get_track_at_position(unsigned int head, unsigned int position)
{
std::shared_ptr<Track> track;
if(head >= _head_count) return track;
long file_offset = (position * _head_count + head) * 256 * 10;
fseek(_file, file_offset, SEEK_SET);
std::vector<Storage::Encodings::MFM::Sector> sectors;
for(int sector = 0; sector < 10; sector++)
{
Storage::Encodings::MFM::Sector new_sector;
new_sector.track = (uint8_t)position;
new_sector.side = 0;
new_sector.sector = (uint8_t)sector;
new_sector.data.resize(256);
fread(&new_sector.data[0], 1, 256, _file);
if(feof(_file))
break;
sectors.push_back(std::move(new_sector));
}
if(sectors.size()) return Storage::Encodings::MFM::GetFMTrackWithSectors(sectors);
return track;
}