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CLK/Storage/Tape/Parsers/Commodore.hpp
2021-03-07 20:48:51 -05:00

139 lines
4.1 KiB
C++

//
// Commodore.hpp
// Clock Signal
//
// Created by Thomas Harte on 06/11/2016.
// Copyright 2016 Thomas Harte. All rights reserved.
//
#ifndef Storage_Tape_Parsers_Commodore_hpp
#define Storage_Tape_Parsers_Commodore_hpp
#include "TapeParser.hpp"
#include <memory>
#include <string>
namespace Storage {
namespace Tape {
namespace Commodore {
enum class WaveType {
Short, Medium, Long, Unrecognised
};
enum class SymbolType {
One, Zero, Word, EndOfBlock, LeadIn
};
struct Header {
enum {
RelocatableProgram,
NonRelocatableProgram,
DataSequenceHeader,
DataBlock,
EndOfTape,
Unknown
} type;
std::vector<uint8_t> data;
std::wstring name;
std::vector<uint8_t> raw_name;
uint16_t starting_address;
uint16_t ending_address;
bool parity_was_valid;
bool duplicate_matched;
/*!
Writes a byte serialised version of this header to @c target, writing at most
@c length bytes.
*/
void serialise(uint8_t *target, uint16_t length);
};
struct Data {
std::vector<uint8_t> data;
bool parity_was_valid;
bool duplicate_matched;
};
class Parser: public Storage::Tape::PulseClassificationParser<WaveType, SymbolType> {
public:
Parser();
/*!
Advances to the next block on the tape, treating it as a header, then consumes, parses, and returns it.
Returns @c nullptr if any wave-encoding level errors are encountered.
*/
std::unique_ptr<Header> get_next_header(const std::shared_ptr<Storage::Tape::Tape> &tape);
/*!
Advances to the next block on the tape, treating it as data, then consumes, parses, and returns it.
Returns @c nullptr if any wave-encoding level errors are encountered.
*/
std::unique_ptr<Data> get_next_data(const std::shared_ptr<Storage::Tape::Tape> &tape);
private:
/*!
Template for the logic in selecting which of two copies of something to consider authoritative,
including setting the duplicate_matched flag.
*/
template<class ObjectType>
std::unique_ptr<ObjectType> duplicate_match(std::unique_ptr<ObjectType> first_copy, std::unique_ptr<ObjectType> second_copy);
std::unique_ptr<Header> get_next_header_body(const std::shared_ptr<Storage::Tape::Tape> &tape, bool is_original);
std::unique_ptr<Data> get_next_data_body(const std::shared_ptr<Storage::Tape::Tape> &tape, bool is_original);
/*!
Finds and completes the next landing zone.
*/
void proceed_to_landing_zone(const std::shared_ptr<Storage::Tape::Tape> &tape, bool is_original);
/*!
Swallows the next byte; sets the error flag if it is not equal to @c value.
*/
void expect_byte(const std::shared_ptr<Storage::Tape::Tape> &tape, uint8_t value);
uint8_t parity_byte_ = 0;
void reset_parity_byte();
uint8_t get_parity_byte();
void add_parity_byte(uint8_t byte);
/*!
Proceeds to the next word marker then returns the result of @c get_next_byte_contents.
*/
uint8_t get_next_byte(const std::shared_ptr<Storage::Tape::Tape> &tape);
/*!
Reads the next nine symbols and applies a binary test to each to differentiate between ::One and not-::One.
Returns a byte composed of the first eight of those as bits; sets the error flag if any symbol is not
::One and not ::Zero, or if the ninth bit is not equal to the odd parity of the other eight.
*/
uint8_t get_next_byte_contents(const std::shared_ptr<Storage::Tape::Tape> &tape);
/*!
Returns the result of two consecutive @c get_next_byte calls, arranged in little-endian format.
*/
uint16_t get_next_short(const std::shared_ptr<Storage::Tape::Tape> &tape);
/*!
Per the contract with Analyser::Static::TapeParser; sums time across pulses. If this pulse
indicates a high to low transition, inspects the time since the last transition, to produce
a long, medium, short or unrecognised wave period.
*/
void process_pulse(const Storage::Tape::Tape::Pulse &pulse) override;
bool previous_was_high_ = false;
float wave_period_ = 0.0f;
/*!
Per the contract with Analyser::Static::TapeParser; produces any of a word marker, an end-of-block marker,
a zero, a one or a lead-in symbol based on the currently captured waves.
*/
void inspect_waves(const std::vector<WaveType> &waves) override;
};
}
}
}
#endif /* Commodore_hpp */