mirror of
https://github.com/TomHarte/CLK.git
synced 2024-11-03 08:05:40 +00:00
e384c50580
Thereby opens a route for file format implementations such as that appearing for CPC DSK that create an in-memory copy and perform a full rewrite.
114 lines
3.0 KiB
C++
114 lines
3.0 KiB
C++
//
|
|
// HFE.cpp
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 17/08/2017.
|
|
// Copyright © 2017 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#include "HFE.hpp"
|
|
|
|
#include "../../Track/PCMTrack.hpp"
|
|
#include "../../Track/TrackSerialiser.hpp"
|
|
#include "../../../Data/BitReverse.hpp"
|
|
|
|
using namespace Storage::Disk;
|
|
|
|
HFE::HFE(const char *file_name) :
|
|
file_(file_name) {
|
|
if(!file_.check_signature("HXCPICFE")) throw ErrorNotHFE;
|
|
|
|
if(file_.get8()) throw ErrorNotHFE;
|
|
track_count_ = file_.get8();
|
|
head_count_ = file_.get8();
|
|
|
|
file_.seek(7, SEEK_CUR);
|
|
track_list_offset_ = static_cast<long>(file_.get16le()) << 9;
|
|
}
|
|
|
|
HFE::~HFE() {
|
|
}
|
|
|
|
int HFE::get_head_position_count() {
|
|
return track_count_;
|
|
}
|
|
|
|
int HFE::get_head_count() {
|
|
return head_count_;
|
|
}
|
|
|
|
/*!
|
|
Seeks to the beginning of the track at @c position underneath @c head,
|
|
returning its length in bytes.
|
|
|
|
To read the track, start from the current file position, read 256 bytes,
|
|
skip 256 bytes, read 256 bytes, skip 256 bytes, etc.
|
|
*/
|
|
uint16_t HFE::seek_track(Track::Address address) {
|
|
// Get track position and length from the lookup table; data is then always interleaved
|
|
// based on an assumption of two heads.
|
|
file_.seek(track_list_offset_ + address.position * 4, SEEK_SET);
|
|
|
|
long track_offset = static_cast<long>(file_.get16le()) << 9;
|
|
uint16_t track_length = file_.get16le();
|
|
|
|
file_.seek(track_offset, SEEK_SET);
|
|
if(address.head) file_.seek(256, SEEK_CUR);
|
|
|
|
return track_length / 2;
|
|
}
|
|
|
|
std::shared_ptr<Track> HFE::get_track_at_position(Track::Address address) {
|
|
PCMSegment segment;
|
|
{
|
|
std::lock_guard<std::mutex> lock_guard(file_.get_file_access_mutex());
|
|
uint16_t track_length = seek_track(address);
|
|
|
|
segment.data.resize(track_length);
|
|
segment.number_of_bits = track_length * 8;
|
|
|
|
uint16_t c = 0;
|
|
while(c < track_length) {
|
|
uint16_t length = static_cast<uint16_t>(std::min(256, track_length - c));
|
|
file_.read(&segment.data[c], length);
|
|
c += length;
|
|
file_.seek(256, SEEK_CUR);
|
|
}
|
|
}
|
|
|
|
// Flip bytes; HFE's preference is that the least-significant bit
|
|
// is serialised first, but PCMTrack posts the most-significant first.
|
|
Storage::Data::BitReverse::reverse(segment.data);
|
|
|
|
std::shared_ptr<Track> track(new PCMTrack(segment));
|
|
return track;
|
|
}
|
|
|
|
void HFE::set_tracks(const std::map<Track::Address, std::shared_ptr<Track>> &tracks) {
|
|
for(auto &track : tracks) {
|
|
std::unique_lock<std::mutex> lock_guard(file_.get_file_access_mutex());
|
|
uint16_t track_length = seek_track(track.first);
|
|
lock_guard.unlock();
|
|
|
|
PCMSegment segment = Storage::Disk::track_serialisation(*track.second, Storage::Time(1, track_length * 8));
|
|
Storage::Data::BitReverse::reverse(segment.data);
|
|
uint16_t data_length = std::min(static_cast<uint16_t>(segment.data.size()), track_length);
|
|
|
|
lock_guard.lock();
|
|
seek_track(track.first);
|
|
|
|
uint16_t c = 0;
|
|
while(c < data_length) {
|
|
uint16_t length = static_cast<uint16_t>(std::min(256, data_length - c));
|
|
file_.write(&segment.data[c], length);
|
|
c += length;
|
|
file_.seek(256, SEEK_CUR);
|
|
}
|
|
lock_guard.unlock();
|
|
}
|
|
}
|
|
|
|
bool HFE::get_is_read_only() {
|
|
return file_.get_is_known_read_only();
|
|
}
|