[pulseview.git] / pv / data / mathsignal.cpp

/*
 * This file is part of the PulseView project.
 *
 * Copyright (C) 2020 Soeren Apel <soeren@apelpie.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include <limits>

#include <QDebug>

#include "mathsignal.hpp"

#include <extdef.h>
#include <pv/globalsettings.hpp>
#include <pv/session.hpp>
#include <pv/data/analogsegment.hpp>
#include <pv/data/signalbase.hpp>

using std::dynamic_pointer_cast;
using std::make_shared;
using std::min;
using std::unique_lock;

namespace pv {
namespace data {

const int64_t MathSignal::ChunkLength = 256 * 1024;


template<typename T>
struct sig_sample : public exprtk::igeneric_function<T>
{
	typedef typename exprtk::igeneric_function<T>::parameter_list_t parameter_list_t;
	typedef typename exprtk::igeneric_function<T>::generic_type generic_type;
	typedef typename generic_type::scalar_view scalar_t;
	typedef typename generic_type::string_view string_t;

	sig_sample(MathSignal& owner) :
		exprtk::igeneric_function<T>("ST"),  // Require channel name and sample number
		owner_(owner),
		sig_data(nullptr)
	{
	}

	T operator()(parameter_list_t parameters)
	{
		const string_t exprtk_sig_name = string_t(parameters[0]);
		const scalar_t exprtk_sample_num = scalar_t(parameters[1]);

		const std::string str_sig_name = to_str(exprtk_sig_name);
		const double sample_num = exprtk_sample_num();

		if (!sig_data)
			sig_data = owner_.signal_from_name(str_sig_name);

		assert(sig_data);
		owner_.update_signal_sample(sig_data, current_segment, sample_num);

		return T(sig_data->sample_value);
	}

	MathSignal& owner_;
	uint32_t current_segment;
	signal_data* sig_data;
};


MathSignal::MathSignal(pv::Session &session) :
	SignalBase(nullptr, SignalBase::MathChannel),
	session_(session),
	use_custom_sample_rate_(false),
	use_custom_sample_count_(false),
	expression_(""),
	exprtk_unknown_symbol_table_(nullptr),
	exprtk_symbol_table_(nullptr),
	exprtk_expression_(nullptr),
	exprtk_parser_(nullptr),
	fnc_sig_sample_(nullptr)
{
	uint32_t sig_idx = session_.get_next_signal_index(MathChannel);
	set_name(QString(tr("Math%1")).arg(sig_idx));
	set_color(AnalogSignalColors[(sig_idx - 1) % countof(AnalogSignalColors)]);

	set_data(std::make_shared<data::Analog>());

	connect(&session_, SIGNAL(capture_state_changed(int)),
		this, SLOT(on_capture_state_changed(int)));
}

MathSignal::~MathSignal()
{
	reset_generation();

	if (fnc_sig_sample_)
		delete fnc_sig_sample_;
}

void MathSignal::save_settings(QSettings &settings) const
{
	settings.setValue("expression", expression_);

	settings.setValue("custom_sample_rate", (qulonglong)custom_sample_rate_);
	settings.setValue("custom_sample_count", (qulonglong)custom_sample_count_);
	settings.setValue("use_custom_sample_rate", use_custom_sample_rate_);
	settings.setValue("use_custom_sample_count", use_custom_sample_count_);
}

void MathSignal::restore_settings(QSettings &settings)
{
	if (settings.contains("expression"))
		expression_ = settings.value("expression").toString();

	if (settings.contains("custom_sample_rate"))
		custom_sample_rate_ = settings.value("custom_sample_rate").toULongLong();

	if (settings.contains("custom_sample_count"))
		custom_sample_count_ = settings.value("custom_sample_count").toULongLong();

	if (settings.contains("use_custom_sample_rate"))
		use_custom_sample_rate_ = settings.value("use_custom_sample_rate").toBool();

	if (settings.contains("use_custom_sample_count"))
		use_custom_sample_count_ = settings.value("use_custom_sample_count").toBool();
}

QString MathSignal::get_expression() const
{
	return expression_;
}

void MathSignal::set_expression(QString expression)
{
	expression_ = expression;

	begin_generation();
}

void MathSignal::set_error_message(QString msg)
{
	error_message_ = msg;
	// TODO Emulate noquote()
	qDebug().nospace() << name() << ": " << msg << "(Expression: '" << expression_ << "')";

	error_message_changed(msg);
}

uint64_t MathSignal::get_working_sample_count(uint32_t segment_id) const
{
	// The working sample count is the highest sample number for
	// which all used signals have data available, so go through all
	// channels and use the lowest overall sample count of the segment

	int64_t result = std::numeric_limits<int64_t>::max();

	if (use_custom_sample_count_)
		// A custom sample count implies that only one segment will be created
		result = (segment_id == 0) ? custom_sample_count_ : 0;
	else {
		if (input_signals_.size() > 0) {
			for (auto input_signal : input_signals_) {
				const shared_ptr<SignalBase>& sb = input_signal.second.sb;

				shared_ptr<Analog> a = sb->analog_data();
				auto analog_segments = a->analog_segments();

				if (analog_segments.size() == 0) {
					result = 0;
					continue;
				}

				const uint32_t highest_segment_id = (analog_segments.size() - 1);
				if (segment_id > highest_segment_id)
					continue;

				const shared_ptr<AnalogSegment> segment = analog_segments.at(segment_id);
				result = min(result, (int64_t)segment->get_sample_count());
			}
		} else
			result = session_.get_segment_sample_count(segment_id);
	}

	return result;
}

void MathSignal::update_completeness(uint32_t segment_id, uint64_t output_sample_count)
{
	bool output_complete = true;

	if (input_signals_.size() > 0) {
		for (auto input_signal : input_signals_) {
			const shared_ptr<SignalBase>& sb = input_signal.second.sb;

			shared_ptr<Analog> a = sb->analog_data();
			auto analog_segments = a->analog_segments();

			if (analog_segments.size() == 0) {
				output_complete = false;
				continue;
			}

			const uint32_t highest_segment_id = (analog_segments.size() - 1);
			if (segment_id > highest_segment_id) {
				output_complete = false;
				continue;
			}

			const shared_ptr<AnalogSegment> segment = analog_segments.at(segment_id);
			if (!segment->is_complete()) {
				output_complete = false;
				continue;
			}

			if (output_sample_count < segment->get_sample_count())
				output_complete = false;
		}
	} else {
		// We're done when we generated as many samples as the stopped session is long
		if ((session_.get_capture_state() != Session::Stopped) ||
			(output_sample_count < session_.get_segment_sample_count(segment_id)))
			output_complete = false;
	}

	if (output_complete)
		analog_data()->analog_segments().at(segment_id)->set_complete();
}

void MathSignal::reset_generation()
{
	if (gen_thread_.joinable()) {
		gen_interrupt_ = true;
		gen_input_cond_.notify_one();
		gen_thread_.join();
	}

	data_->clear();
	input_signals_.clear();

	if (exprtk_parser_) {
		delete exprtk_parser_;
		exprtk_parser_ = nullptr;
	}

	if (exprtk_expression_) {
		delete exprtk_expression_;
		exprtk_expression_ = nullptr;
	}

	if (exprtk_symbol_table_) {
		delete exprtk_symbol_table_;
		exprtk_symbol_table_ = nullptr;
	}

	if (exprtk_unknown_symbol_table_) {
		delete exprtk_unknown_symbol_table_;
		exprtk_unknown_symbol_table_ = nullptr;
	}

	if (fnc_sig_sample_) {
		delete fnc_sig_sample_;
		fnc_sig_sample_ = nullptr;
	}

	if (!error_message_.isEmpty()) {
		error_message_ = QString();
		// TODO Emulate noquote()
		qDebug().nospace() << name() << ": Error cleared";
	}
}

void MathSignal::begin_generation()
{
	reset_generation();

	if (expression_.isEmpty()) {
		set_error_message(tr("No expression defined, nothing to do"));
		return;
	}

	disconnect(this, SLOT(on_data_received()));

	fnc_sig_sample_ = new sig_sample<double>(*this);

	exprtk_unknown_symbol_table_ = new exprtk::symbol_table<double>();

	exprtk_symbol_table_ = new exprtk::symbol_table<double>();
	exprtk_symbol_table_->add_function("sig_sample", *fnc_sig_sample_);
	exprtk_symbol_table_->add_variable("t", exprtk_current_time_);
	exprtk_symbol_table_->add_variable("s", exprtk_current_sample_);
	exprtk_symbol_table_->add_constants();

	exprtk_expression_ = new exprtk::expression<double>();
	exprtk_expression_->register_symbol_table(*exprtk_unknown_symbol_table_);
	exprtk_expression_->register_symbol_table(*exprtk_symbol_table_);

	exprtk_parser_ = new exprtk::parser<double>();
	exprtk_parser_->enable_unknown_symbol_resolver();

	if (!exprtk_parser_->compile(expression_.toStdString(), *exprtk_expression_)) {
		QString error_details;
		size_t error_count = exprtk_parser_->error_count();

		for (size_t i = 0; i < error_count; i++) {
			typedef exprtk::parser_error::type error_t;
			error_t error = exprtk_parser_->get_error(i);
			exprtk::parser_error::update_error(error, expression_.toStdString());

			QString error_detail = tr("%1 at line %2, column %3: %4");
			if ((error_count > 1) && (i < (error_count - 1)))
				error_detail += "\n";

			error_details += error_detail \
				.arg(exprtk::parser_error::to_str(error.mode).c_str()) \
				.arg(error.line_no) \
				.arg(error.column_no) \
				.arg(error.diagnostic.c_str());
		}
		set_error_message(error_details);
	} else {
		// Resolve unknown scalars to signals and add them to the input signal list
		vector<string> unknowns;
		exprtk_unknown_symbol_table_->get_variable_list(unknowns);
		for (string& unknown : unknowns) {
			signal_data* sig_data = signal_from_name(unknown);
			const shared_ptr<SignalBase> signal = (sig_data) ? (sig_data->sb) : nullptr;
			if (!signal || (!signal->analog_data())) {
				set_error_message(QString(tr("%1 isn't a valid analog signal")).arg(
					QString::fromStdString(unknown)));
			} else
				sig_data->ref = &(exprtk_unknown_symbol_table_->variable_ref(unknown));
		}
	}

	if (error_message_.isEmpty()) {
		// Connect to the session data notification if we have no input signals
		if (input_signals_.empty())
			connect(&session_, SIGNAL(data_received()),
				this, SLOT(on_data_received()));

		gen_interrupt_ = false;
		gen_thread_ = std::thread(&MathSignal::generation_proc, this);
	}
}

void MathSignal::generate_samples(uint32_t segment_id, const uint64_t start_sample,
	const int64_t sample_count)
{
	shared_ptr<Analog> analog = dynamic_pointer_cast<Analog>(data_);
	shared_ptr<AnalogSegment> segment = analog->analog_segments().at(segment_id);

	// Keep the math functions segment IDs in sync
	fnc_sig_sample_->current_segment = segment_id;

	const double sample_rate = data_->get_samplerate();

	exprtk_current_sample_ = start_sample;

	float *sample_data = new float[sample_count];

	for (int64_t i = 0; i < sample_count; i++) {
		exprtk_current_time_ = exprtk_current_sample_ / sample_rate;

		for (auto& entry : input_signals_) {
			signal_data* sig_data  = &(entry.second);
			update_signal_sample(sig_data, segment_id, exprtk_current_sample_);
		}

		double value = exprtk_expression_->value();
		sample_data[i] = value;
		exprtk_current_sample_ += 1;
	}

	segment->append_interleaved_samples(sample_data, sample_count, 1);

	delete[] sample_data;
}

void MathSignal::generation_proc()
{
	// Don't do anything until we have a valid sample rate
	do {
		if (use_custom_sample_rate_)
			data_->set_samplerate(custom_sample_rate_);
		else
			data_->set_samplerate(session_.get_samplerate());

		if (data_->get_samplerate() == 1) {
			unique_lock<mutex> gen_input_lock(input_mutex_);
			gen_input_cond_.wait(gen_input_lock);
		}
	} while ((!gen_interrupt_) && (data_->get_samplerate() == 1));

	if (gen_interrupt_)
		return;

	uint32_t segment_id = 0;
	shared_ptr<Analog> analog = analog_data();

	// Create initial analog segment
	shared_ptr<AnalogSegment> output_segment =
		make_shared<AnalogSegment>(*analog.get(), segment_id, analog->get_samplerate());
	analog->push_segment(output_segment);

	// Create analog samples
	do {
		const uint64_t input_sample_count = get_working_sample_count(segment_id);
		const uint64_t output_sample_count = output_segment->get_sample_count();

		const uint64_t samples_to_process =
			(input_sample_count > output_sample_count) ?
			(input_sample_count - output_sample_count) : 0;

		// Process the samples if necessary...
		if (samples_to_process > 0) {
			const uint64_t chunk_sample_count = ChunkLength;

			uint64_t processed_samples = 0;
			do {
				const uint64_t start_sample = output_sample_count + processed_samples;
				const uint64_t sample_count =
					min(samples_to_process - processed_samples,	chunk_sample_count);

				generate_samples(segment_id, start_sample, sample_count);
				processed_samples += sample_count;

				// Notify consumers of this signal's data
				samples_added(segment_id, start_sample, start_sample + processed_samples);
			} while (!gen_interrupt_ && (processed_samples < samples_to_process));
		}

		update_completeness(segment_id, output_sample_count);

		if (output_segment->is_complete() && (segment_id < session_.get_highest_segment_id())) {
				// Process next segment
				segment_id++;

				output_segment =
					make_shared<AnalogSegment>(*analog.get(), segment_id, analog->get_samplerate());
				analog->push_segment(output_segment);
		}

		if (!gen_interrupt_ && (samples_to_process == 0)) {
			// Wait for more input
			unique_lock<mutex> gen_input_lock(input_mutex_);
			gen_input_cond_.wait(gen_input_lock);
		}
	} while (!gen_interrupt_);
}

signal_data* MathSignal::signal_from_name(const std::string& name)
{
	// Look up signal in the map and if it doesn't exist yet, add it for future use

	auto element = input_signals_.find(name);

	if (element != input_signals_.end()) {
		return &(element->second);
	} else {
		const vector< shared_ptr<SignalBase> > signalbases = session_.signalbases();
		const QString sig_name = QString::fromStdString(name);

		for (const shared_ptr<SignalBase>& sb : signalbases)
			if (sb->name() == sig_name) {
				if (!sb->analog_data())
					continue;

				connect(sb->analog_data().get(), SIGNAL(samples_added(SharedPtrToSegment, uint64_t, uint64_t)),
					this, SLOT(on_data_received()));
				connect(sb->analog_data().get(), SIGNAL(segment_completed()),
					this, SLOT(on_data_received()));

				return &(input_signals_.insert({name, signal_data(sb)}).first->second);
			}
	}

	return nullptr;
}

void MathSignal::update_signal_sample(signal_data* sig_data, uint32_t segment_id, uint64_t sample_num)
{
	assert(sig_data);

	// Update the value only if a different sample is requested
	if (sig_data->sample_num == sample_num)
		return;

	assert(sig_data->sb);
	const shared_ptr<pv::data::Analog> analog = sig_data->sb->analog_data();
	assert(analog);

	assert(segment_id < analog->analog_segments().size());

	const shared_ptr<AnalogSegment> segment = analog->analog_segments().at(segment_id);

	sig_data->sample_num = sample_num;
	sig_data->sample_value = segment->get_sample(sample_num);

	// We only have a reference if this signal is used as a scalar;
	// if it's used by a function, it's null
	if (sig_data->ref)
		*(sig_data->ref) = sig_data->sample_value;
}

void MathSignal::on_capture_state_changed(int state)
{
	if (state == Session::Running)
		begin_generation();

	// Make sure we don't miss any input samples, just in case
	if (state == Session::Stopped)
		gen_input_cond_.notify_one();
}

void MathSignal::on_data_received()
{
	gen_input_cond_.notify_one();
}

} // namespace data
} // namespace pv
Commit	Line	Data
b0773a8a SA	1	/*
	2	* This file is part of the PulseView project.
	3	*
	4	* Copyright (C) 2020 Soeren Apel <soeren@apelpie.net>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, see <http://www.gnu.org/licenses/>.
	18	*/
	19
	20	#include <limits>
	21
	22	#include <QDebug>
	23
	24	#include "mathsignal.hpp"
	25
516b0c41	26	#include <extdef.h>
b0773a8a SA	27	#include <pv/globalsettings.hpp>
	28	#include <pv/session.hpp>
	29	#include <pv/data/analogsegment.hpp>
	30	#include <pv/data/signalbase.hpp>
	31
4640a84e	32	using std::dynamic_pointer_cast;
b0773a8a	33	using std::make_shared;
4640a84e SA	34	using std::min;
4640a84e SA	35	using std::unique_lock;
b0773a8a SA	36
	37	namespace pv {
	38	namespace data {
	39
	40	const int64_t MathSignal::ChunkLength = 256 * 1024;
	41
	42
3f1f6295 SA	43	template<typename T>
	44	struct sig_sample : public exprtk::igeneric_function<T>
	45	{
	46	typedef typename exprtk::igeneric_function<T>::parameter_list_t parameter_list_t;
	47	typedef typename exprtk::igeneric_function<T>::generic_type generic_type;
	48	typedef typename generic_type::scalar_view scalar_t;
	49	typedef typename generic_type::string_view string_t;
	50
	51	sig_sample(MathSignal& owner) :
	52	exprtk::igeneric_function<T>("ST"), // Require channel name and sample number
	53	owner_(owner),
	54	sig_data(nullptr)
	55	{
	56	}
	57
	58	T operator()(parameter_list_t parameters)
	59	{
	60	const string_t exprtk_sig_name = string_t(parameters[0]);
	61	const scalar_t exprtk_sample_num = scalar_t(parameters[1]);
	62
	63	const std::string str_sig_name = to_str(exprtk_sig_name);
	64	const double sample_num = exprtk_sample_num();
	65
	66	if (!sig_data)
	67	sig_data = owner_.signal_from_name(str_sig_name);
	68
	69	assert(sig_data);
	70	owner_.update_signal_sample(sig_data, current_segment, sample_num);
	71
	72	return T(sig_data->sample_value);
	73	}
	74
	75	MathSignal& owner_;
	76	uint32_t current_segment;
	77	signal_data* sig_data;
	78	};
	79
	80
b0773a8a SA	81	MathSignal::MathSignal(pv::Session &session) :
b0773a8a SA	82	SignalBase(nullptr, SignalBase::MathChannel),
4640a84e SA	83	session_(session),
	84	use_custom_sample_rate_(false),
	85	use_custom_sample_count_(false),
	86	expression_(""),
3f1f6295	87	exprtk_unknown_symbol_table_(nullptr),
4640a84e SA	88	exprtk_symbol_table_(nullptr),
4640a84e SA	89	exprtk_expression_(nullptr),
3f1f6295 SA	90	exprtk_parser_(nullptr),
3f1f6295 SA	91	fnc_sig_sample_(nullptr)
b0773a8a	92	{
516b0c41 SA	93	uint32_t sig_idx = session_.get_next_signal_index(MathChannel);
	94	set_name(QString(tr("Math%1")).arg(sig_idx));
	95	set_color(AnalogSignalColors[(sig_idx - 1) % countof(AnalogSignalColors)]);
4640a84e	96
5eb9d1c4	97	set_data(std::make_shared<data::Analog>());
b0773a8a	98
4640a84e SA	99	connect(&session_, SIGNAL(capture_state_changed(int)),
4640a84e SA	100	this, SLOT(on_capture_state_changed(int)));
b0773a8a SA	101	}
	102
	103	MathSignal::~MathSignal()
	104	{
4640a84e	105	reset_generation();
3f1f6295 SA	106
	107	if (fnc_sig_sample_)
	108	delete fnc_sig_sample_;
b0773a8a SA	109	}
	110
	111	void MathSignal::save_settings(QSettings &settings) const
	112	{
4640a84e SA	113	settings.setValue("expression", expression_);
	114
	115	settings.setValue("custom_sample_rate", (qulonglong)custom_sample_rate_);
	116	settings.setValue("custom_sample_count", (qulonglong)custom_sample_count_);
	117	settings.setValue("use_custom_sample_rate", use_custom_sample_rate_);
	118	settings.setValue("use_custom_sample_count", use_custom_sample_count_);
b0773a8a SA	119	}
	120
	121	void MathSignal::restore_settings(QSettings &settings)
	122	{
4640a84e SA	123	if (settings.contains("expression"))
	124	expression_ = settings.value("expression").toString();
	125
	126	if (settings.contains("custom_sample_rate"))
	127	custom_sample_rate_ = settings.value("custom_sample_rate").toULongLong();
	128
	129	if (settings.contains("custom_sample_count"))
	130	custom_sample_count_ = settings.value("custom_sample_count").toULongLong();
	131
	132	if (settings.contains("use_custom_sample_rate"))
	133	use_custom_sample_rate_ = settings.value("use_custom_sample_rate").toBool();
	134
	135	if (settings.contains("use_custom_sample_count"))
	136	use_custom_sample_count_ = settings.value("use_custom_sample_count").toBool();
	137	}
	138
4640a84e SA	139	QString MathSignal::get_expression() const
	140	{
	141	return expression_;
	142	}
	143
	144	void MathSignal::set_expression(QString expression)
	145	{
	146	expression_ = expression;
	147
	148	begin_generation();
	149	}
	150
	151	void MathSignal::set_error_message(QString msg)
	152	{
	153	error_message_ = msg;
	154	// TODO Emulate noquote()
d203009f	155	qDebug().nospace() << name() << ": " << msg << "(Expression: '" << expression_ << "')";
f6a93932 SA	156
f6a93932 SA	157	error_message_changed(msg);
4640a84e SA	158	}
	159
	160	uint64_t MathSignal::get_working_sample_count(uint32_t segment_id) const
	161	{
	162	// The working sample count is the highest sample number for
	163	// which all used signals have data available, so go through all
	164	// channels and use the lowest overall sample count of the segment
	165
	166	int64_t result = std::numeric_limits<int64_t>::max();
	167
	168	if (use_custom_sample_count_)
	169	// A custom sample count implies that only one segment will be created
	170	result = (segment_id == 0) ? custom_sample_count_ : 0;
	171	else {
	172	if (input_signals_.size() > 0) {
3f1f6295 SA	173	for (auto input_signal : input_signals_) {
	174	const shared_ptr<SignalBase>& sb = input_signal.second.sb;
	175
4640a84e	176	shared_ptr<Analog> a = sb->analog_data();
bee54d9e SA	177	auto analog_segments = a->analog_segments();
	178
	179	if (analog_segments.size() == 0) {
	180	result = 0;
	181	continue;
	182	}
	183
	184	const uint32_t highest_segment_id = (analog_segments.size() - 1);
	185	if (segment_id > highest_segment_id)
4640a84e	186	continue;
bee54d9e SA	187
bee54d9e SA	188	const shared_ptr<AnalogSegment> segment = analog_segments.at(segment_id);
4640a84e SA	189	result = min(result, (int64_t)segment->get_sample_count());
	190	}
	191	} else
	192	result = session_.get_segment_sample_count(segment_id);
	193	}
	194
	195	return result;
	196	}
	197
144e72c9	198	void MathSignal::update_completeness(uint32_t segment_id, uint64_t output_sample_count)
bee54d9e SA	199	{
	200	bool output_complete = true;
	201
	202	if (input_signals_.size() > 0) {
	203	for (auto input_signal : input_signals_) {
	204	const shared_ptr<SignalBase>& sb = input_signal.second.sb;
	205
	206	shared_ptr<Analog> a = sb->analog_data();
	207	auto analog_segments = a->analog_segments();
	208
	209	if (analog_segments.size() == 0) {
	210	output_complete = false;
	211	continue;
	212	}
	213
	214	const uint32_t highest_segment_id = (analog_segments.size() - 1);
	215	if (segment_id > highest_segment_id) {
	216	output_complete = false;
	217	continue;
	218	}
	219
	220	const shared_ptr<AnalogSegment> segment = analog_segments.at(segment_id);
144e72c9 SA	221	if (!segment->is_complete()) {
	222	output_complete = false;
	223	continue;
	224	}
	225
	226	if (output_sample_count < segment->get_sample_count())
bee54d9e SA	227	output_complete = false;
bee54d9e SA	228	}
144e72c9 SA	229	} else {
	230	// We're done when we generated as many samples as the stopped session is long
	231	if ((session_.get_capture_state() != Session::Stopped) \|\|
	232	(output_sample_count < session_.get_segment_sample_count(segment_id)))
	233	output_complete = false;
bee54d9e SA	234	}
	235
	236	if (output_complete)
	237	analog_data()->analog_segments().at(segment_id)->set_complete();
	238	}
	239
4640a84e SA	240	void MathSignal::reset_generation()
	241	{
	242	if (gen_thread_.joinable()) {
	243	gen_interrupt_ = true;
	244	gen_input_cond_.notify_one();
	245	gen_thread_.join();
	246	}
	247
	248	data_->clear();
3f1f6295	249	input_signals_.clear();
4640a84e	250
3f1f6295 SA	251	if (exprtk_parser_) {
	252	delete exprtk_parser_;
	253	exprtk_parser_ = nullptr;
4640a84e SA	254	}
	255
	256	if (exprtk_expression_) {
	257	delete exprtk_expression_;
	258	exprtk_expression_ = nullptr;
	259	}
	260
3f1f6295 SA	261	if (exprtk_symbol_table_) {
	262	delete exprtk_symbol_table_;
	263	exprtk_symbol_table_ = nullptr;
	264	}
	265
	266	if (exprtk_unknown_symbol_table_) {
	267	delete exprtk_unknown_symbol_table_;
	268	exprtk_unknown_symbol_table_ = nullptr;
	269	}
	270
	271	if (fnc_sig_sample_) {
	272	delete fnc_sig_sample_;
	273	fnc_sig_sample_ = nullptr;
4640a84e SA	274	}
	275
	276	if (!error_message_.isEmpty()) {
	277	error_message_ = QString();
	278	// TODO Emulate noquote()
	279	qDebug().nospace() << name() << ": Error cleared";
	280	}
	281	}
	282
	283	void MathSignal::begin_generation()
	284	{
	285	reset_generation();
	286
	287	if (expression_.isEmpty()) {
	288	set_error_message(tr("No expression defined, nothing to do"));
	289	return;
	290	}
	291
144e72c9 SA	292	disconnect(this, SLOT(on_data_received()));
144e72c9 SA	293
3f1f6295 SA	294	fnc_sig_sample_ = new sig_sample<double>(*this);
	295
	296	exprtk_unknown_symbol_table_ = new exprtk::symbol_table<double>();
	297
4640a84e	298	exprtk_symbol_table_ = new exprtk::symbol_table<double>();
3f1f6295	299	exprtk_symbol_table_->add_function("sig_sample", *fnc_sig_sample_);
4640a84e SA	300	exprtk_symbol_table_->add_variable("t", exprtk_current_time_);
	301	exprtk_symbol_table_->add_variable("s", exprtk_current_sample_);
	302	exprtk_symbol_table_->add_constants();
	303
	304	exprtk_expression_ = new exprtk::expression<double>();
3f1f6295	305	exprtk_expression_->register_symbol_table(*exprtk_unknown_symbol_table_);
4640a84e SA	306	exprtk_expression_->register_symbol_table(*exprtk_symbol_table_);
	307
	308	exprtk_parser_ = new exprtk::parser<double>();
3f1f6295 SA	309	exprtk_parser_->enable_unknown_symbol_resolver();
3f1f6295 SA	310
d203009f	311	if (!exprtk_parser_->compile(expression_.toStdString(), *exprtk_expression_)) {
f6a93932 SA	312	QString error_details;
	313	size_t error_count = exprtk_parser_->error_count();
	314
	315	for (size_t i = 0; i < error_count; i++) {
	316	typedef exprtk::parser_error::type error_t;
	317	error_t error = exprtk_parser_->get_error(i);
	318	exprtk::parser_error::update_error(error, expression_.toStdString());
	319
	320	QString error_detail = tr("%1 at line %2, column %3: %4");
	321	if ((error_count > 1) && (i < (error_count - 1)))
	322	error_detail += "\n";
	323
	324	error_details += error_detail \
	325	.arg(exprtk::parser_error::to_str(error.mode).c_str()) \
	326	.arg(error.line_no) \
	327	.arg(error.column_no) \
	328	.arg(error.diagnostic.c_str());
	329	}
	330	set_error_message(error_details);
d203009f	331	} else {
3f1f6295 SA	332	// Resolve unknown scalars to signals and add them to the input signal list
	333	vector<string> unknowns;
	334	exprtk_unknown_symbol_table_->get_variable_list(unknowns);
	335	for (string& unknown : unknowns) {
	336	signal_data* sig_data = signal_from_name(unknown);
	337	const shared_ptr<SignalBase> signal = (sig_data) ? (sig_data->sb) : nullptr;
	338	if (!signal \|\| (!signal->analog_data())) {
bee54d9e	339	set_error_message(QString(tr("%1 isn't a valid analog signal")).arg(
3f1f6295 SA	340	QString::fromStdString(unknown)));
	341	} else
	342	sig_data->ref = &(exprtk_unknown_symbol_table_->variable_ref(unknown));
	343	}
	344	}
	345
	346	if (error_message_.isEmpty()) {
144e72c9 SA	347	// Connect to the session data notification if we have no input signals
	348	if (input_signals_.empty())
	349	connect(&session_, SIGNAL(data_received()),
	350	this, SLOT(on_data_received()));
	351
d203009f SA	352	gen_interrupt_ = false;
	353	gen_thread_ = std::thread(&MathSignal::generation_proc, this);
	354	}
4640a84e SA	355	}
	356
	357	void MathSignal::generate_samples(uint32_t segment_id, const uint64_t start_sample,
	358	const int64_t sample_count)
	359	{
	360	shared_ptr<Analog> analog = dynamic_pointer_cast<Analog>(data_);
	361	shared_ptr<AnalogSegment> segment = analog->analog_segments().at(segment_id);
	362
3f1f6295 SA	363	// Keep the math functions segment IDs in sync
	364	fnc_sig_sample_->current_segment = segment_id;
	365
4640a84e SA	366	const double sample_rate = data_->get_samplerate();
	367
	368	exprtk_current_sample_ = start_sample;
	369
	370	float *sample_data = new float[sample_count];
	371
	372	for (int64_t i = 0; i < sample_count; i++) {
4640a84e	373	exprtk_current_time_ = exprtk_current_sample_ / sample_rate;
3f1f6295 SA	374
	375	for (auto& entry : input_signals_) {
	376	signal_data* sig_data = &(entry.second);
	377	update_signal_sample(sig_data, segment_id, exprtk_current_sample_);
	378	}
	379
4640a84e SA	380	double value = exprtk_expression_->value();
4640a84e SA	381	sample_data[i] = value;
3f1f6295	382	exprtk_current_sample_ += 1;
4640a84e SA	383	}
	384
	385	segment->append_interleaved_samples(sample_data, sample_count, 1);
	386
	387	delete[] sample_data;
	388	}
	389
	390	void MathSignal::generation_proc()
	391	{
4640a84e SA	392	// Don't do anything until we have a valid sample rate
	393	do {
	394	if (use_custom_sample_rate_)
	395	data_->set_samplerate(custom_sample_rate_);
	396	else
	397	data_->set_samplerate(session_.get_samplerate());
	398
	399	if (data_->get_samplerate() == 1) {
	400	unique_lock<mutex> gen_input_lock(input_mutex_);
	401	gen_input_cond_.wait(gen_input_lock);
	402	}
	403	} while ((!gen_interrupt_) && (data_->get_samplerate() == 1));
	404
	405	if (gen_interrupt_)
	406	return;
	407
144e72c9	408	uint32_t segment_id = 0;
5eb9d1c4	409	shared_ptr<Analog> analog = analog_data();
4640a84e SA	410
	411	// Create initial analog segment
	412	shared_ptr<AnalogSegment> output_segment =
	413	make_shared<AnalogSegment>(*analog.get(), segment_id, analog->get_samplerate());
	414	analog->push_segment(output_segment);
	415
	416	// Create analog samples
	417	do {
	418	const uint64_t input_sample_count = get_working_sample_count(segment_id);
	419	const uint64_t output_sample_count = output_segment->get_sample_count();
	420
	421	const uint64_t samples_to_process =
	422	(input_sample_count > output_sample_count) ?
	423	(input_sample_count - output_sample_count) : 0;
	424
	425	// Process the samples if necessary...
	426	if (samples_to_process > 0) {
	427	const uint64_t chunk_sample_count = ChunkLength;
	428
	429	uint64_t processed_samples = 0;
	430	do {
	431	const uint64_t start_sample = output_sample_count + processed_samples;
	432	const uint64_t sample_count =
	433	min(samples_to_process - processed_samples, chunk_sample_count);
	434
	435	generate_samples(segment_id, start_sample, sample_count);
	436	processed_samples += sample_count;
	437
	438	// Notify consumers of this signal's data
4640a84e SA	439	samples_added(segment_id, start_sample, start_sample + processed_samples);
	440	} while (!gen_interrupt_ && (processed_samples < samples_to_process));
	441	}
	442
144e72c9	443	update_completeness(segment_id, output_sample_count);
5eb9d1c4	444
144e72c9	445	if (output_segment->is_complete() && (segment_id < session_.get_highest_segment_id())) {
4640a84e SA	446	// Process next segment
	447	segment_id++;
	448
	449	output_segment =
	450	make_shared<AnalogSegment>(*analog.get(), segment_id, analog->get_samplerate());
	451	analog->push_segment(output_segment);
4640a84e SA	452	}
4640a84e SA	453
144e72c9 SA	454	if (!gen_interrupt_ && (samples_to_process == 0)) {
	455	// Wait for more input
	456	unique_lock<mutex> gen_input_lock(input_mutex_);
	457	gen_input_cond_.wait(gen_input_lock);
	458	}
4640a84e SA	459	} while (!gen_interrupt_);
	460	}
	461
3f1f6295 SA	462	signal_data* MathSignal::signal_from_name(const std::string& name)
	463	{
	464	// Look up signal in the map and if it doesn't exist yet, add it for future use
	465
	466	auto element = input_signals_.find(name);
	467
	468	if (element != input_signals_.end()) {
	469	return &(element->second);
	470	} else {
	471	const vector< shared_ptr<SignalBase> > signalbases = session_.signalbases();
	472	const QString sig_name = QString::fromStdString(name);
	473
	474	for (const shared_ptr<SignalBase>& sb : signalbases)
bee54d9e SA	475	if (sb->name() == sig_name) {
	476	if (!sb->analog_data())
	477	continue;
	478
144e72c9 SA	479	connect(sb->analog_data().get(), SIGNAL(samples_added(SharedPtrToSegment, uint64_t, uint64_t)),
144e72c9 SA	480	this, SLOT(on_data_received()));
bee54d9e SA	481	connect(sb->analog_data().get(), SIGNAL(segment_completed()),
	482	this, SLOT(on_data_received()));
	483
3f1f6295	484	return &(input_signals_.insert({name, signal_data(sb)}).first->second);
bee54d9e	485	}
3f1f6295 SA	486	}
	487
	488	return nullptr;
	489	}
	490
	491	void MathSignal::update_signal_sample(signal_data* sig_data, uint32_t segment_id, uint64_t sample_num)
	492	{
	493	assert(sig_data);
	494
	495	// Update the value only if a different sample is requested
	496	if (sig_data->sample_num == sample_num)
	497	return;
	498
	499	assert(sig_data->sb);
	500	const shared_ptr<pv::data::Analog> analog = sig_data->sb->analog_data();
	501	assert(analog);
	502
	503	assert(segment_id < analog->analog_segments().size());
	504
	505	const shared_ptr<AnalogSegment> segment = analog->analog_segments().at(segment_id);
	506
	507	sig_data->sample_num = sample_num;
	508	sig_data->sample_value = segment->get_sample(sample_num);
	509
144e72c9	510	// We only have a reference if this signal is used as a scalar;
3f1f6295 SA	511	// if it's used by a function, it's null
	512	if (sig_data->ref)
	513	*(sig_data->ref) = sig_data->sample_value;
	514	}
	515
4640a84e SA	516	void MathSignal::on_capture_state_changed(int state)
	517	{
	518	if (state == Session::Running)
	519	begin_generation();
5eb9d1c4	520
144e72c9 SA	521	// Make sure we don't miss any input samples, just in case
	522	if (state == Session::Stopped)
	523	gen_input_cond_.notify_one();
4640a84e SA	524	}
	525
	526	void MathSignal::on_data_received()
	527	{
	528	gen_input_cond_.notify_one();
b0773a8a SA	529	}
	530
	531	} // namespace data
	532	} // namespace pv