pv/data/mathsignal.cpp

   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
  26 #include <extdef.h>
  27 #include <pv/globalsettings.hpp>
  28 #include <pv/session.hpp>
  29 #include <pv/data/analogsegment.hpp>
  30 #include <pv/data/signalbase.hpp>
  31
  32 using std::dynamic_pointer_cast;
  33 using std::make_shared;
  34 using std::min;
  35 using std::unique_lock;
  36
  37 namespace pv {
  38 namespace data {
  39
  40 const int64_t MathSignal::ChunkLength = 256 * 1024;
  41
  42
  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
  81 MathSignal::MathSignal(pv::Session &session) :
  82         SignalBase(nullptr, SignalBase::MathChannel),
  83         session_(session),
  84         use_custom_sample_rate_(false),
  85         use_custom_sample_count_(false),
  86         expression_(""),
  87         error_message_(""),
  88         exprtk_unknown_symbol_table_(nullptr),
  89         exprtk_symbol_table_(nullptr),
  90         exprtk_expression_(nullptr),
  91         exprtk_parser_(nullptr),
  92         fnc_sig_sample_(nullptr)
  93 {
  94         uint32_t sig_idx = session_.get_next_signal_index(MathChannel);
  95         set_name(QString(tr("Math%1")).arg(sig_idx));
  96         set_color(AnalogSignalColors[(sig_idx - 1) % countof(AnalogSignalColors)]);
  97
  98         set_data(std::make_shared<data::Analog>());
  99
 100         connect(&session_, SIGNAL(capture_state_changed(int)),
 101                 this, SLOT(on_capture_state_changed(int)));
 102         connect(&session_, SIGNAL(data_received()),
 103                 this, SLOT(on_data_received()));
 104
 105         expression_ = "sin(2 * pi * t) + cos(t / 2 * pi)";
 106 }
 107
 108 MathSignal::~MathSignal()
 109 {
 110         reset_generation();
 111
 112         if (fnc_sig_sample_)
 113                 delete fnc_sig_sample_;
 114 }
 115
 116 void MathSignal::save_settings(QSettings &settings) const
 117 {
 118         settings.setValue("expression", expression_);
 119
 120         settings.setValue("custom_sample_rate", (qulonglong)custom_sample_rate_);
 121         settings.setValue("custom_sample_count", (qulonglong)custom_sample_count_);
 122         settings.setValue("use_custom_sample_rate", use_custom_sample_rate_);
 123         settings.setValue("use_custom_sample_count", use_custom_sample_count_);
 124 }
 125
 126 void MathSignal::restore_settings(QSettings &settings)
 127 {
 128         if (settings.contains("expression"))
 129                 expression_ = settings.value("expression").toString();
 130
 131         if (settings.contains("custom_sample_rate"))
 132                 custom_sample_rate_ = settings.value("custom_sample_rate").toULongLong();
 133
 134         if (settings.contains("custom_sample_count"))
 135                 custom_sample_count_ = settings.value("custom_sample_count").toULongLong();
 136
 137         if (settings.contains("use_custom_sample_rate"))
 138                 use_custom_sample_rate_ = settings.value("use_custom_sample_rate").toBool();
 139
 140         if (settings.contains("use_custom_sample_count"))
 141                 use_custom_sample_count_ = settings.value("use_custom_sample_count").toBool();
 142 }
 143
 144 QString MathSignal::error_message() const
 145 {
 146         return error_message_;
 147 }
 148
 149 QString MathSignal::get_expression() const
 150 {
 151         return expression_;
 152 }
 153
 154 void MathSignal::set_expression(QString expression)
 155 {
 156         expression_ = expression;
 157
 158         begin_generation();
 159 }
 160
 161 void MathSignal::set_error_message(QString msg)
 162 {
 163         error_message_ = msg;
 164         // TODO Emulate noquote()
 165         qDebug().nospace() << name() << ": " << msg << "(Expression: '" << expression_ << "')";
 166 }
 167
 168 uint64_t MathSignal::get_working_sample_count(uint32_t segment_id) const
 169 {
 170         // The working sample count is the highest sample number for
 171         // which all used signals have data available, so go through all
 172         // channels and use the lowest overall sample count of the segment
 173
 174         int64_t result = std::numeric_limits<int64_t>::max();
 175
 176         if (use_custom_sample_count_)
 177                 // A custom sample count implies that only one segment will be created
 178                 result = (segment_id == 0) ? custom_sample_count_ : 0;
 179         else {
 180                 if (input_signals_.size() > 0) {
 181                         for (auto input_signal : input_signals_) {
 182                                 const shared_ptr<SignalBase>& sb = input_signal.second.sb;
 183
 184                                 shared_ptr<Analog> a = sb->analog_data();
 185                                 const uint32_t last_segment = (a->analog_segments().size() - 1);
 186                                 if (segment_id > last_segment)
 187                                         continue;
 188                                 const shared_ptr<AnalogSegment> segment = a->analog_segments()[segment_id];
 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
 198 void MathSignal::reset_generation()
 199 {
 200         if (gen_thread_.joinable()) {
 201                 gen_interrupt_ = true;
 202                 gen_input_cond_.notify_one();
 203                 gen_thread_.join();
 204         }
 205
 206         data_->clear();
 207         input_signals_.clear();
 208
 209         if (exprtk_parser_) {
 210                 delete exprtk_parser_;
 211                 exprtk_parser_ = nullptr;
 212         }
 213
 214         if (exprtk_expression_) {
 215                 delete exprtk_expression_;
 216                 exprtk_expression_ = nullptr;
 217         }
 218
 219         if (exprtk_symbol_table_) {
 220                 delete exprtk_symbol_table_;
 221                 exprtk_symbol_table_ = nullptr;
 222         }
 223
 224         if (exprtk_unknown_symbol_table_) {
 225                 delete exprtk_unknown_symbol_table_;
 226                 exprtk_unknown_symbol_table_ = nullptr;
 227         }
 228
 229         if (fnc_sig_sample_) {
 230                 delete fnc_sig_sample_;
 231                 fnc_sig_sample_ = nullptr;
 232         }
 233
 234         if (!error_message_.isEmpty()) {
 235                 error_message_ = QString();
 236                 // TODO Emulate noquote()
 237                 qDebug().nospace() << name() << ": Error cleared";
 238         }
 239 }
 240
 241 void MathSignal::begin_generation()
 242 {
 243         reset_generation();
 244
 245         if (expression_.isEmpty()) {
 246                 set_error_message(tr("No expression defined, nothing to do"));
 247                 return;
 248         }
 249
 250         fnc_sig_sample_ = new sig_sample<double>(*this);
 251
 252         exprtk_unknown_symbol_table_ = new exprtk::symbol_table<double>();
 253
 254         exprtk_symbol_table_ = new exprtk::symbol_table<double>();
 255         exprtk_symbol_table_->add_function("sig_sample", *fnc_sig_sample_);
 256         exprtk_symbol_table_->add_variable("t", exprtk_current_time_);
 257         exprtk_symbol_table_->add_variable("s", exprtk_current_sample_);
 258         exprtk_symbol_table_->add_constants();
 259
 260         exprtk_expression_ = new exprtk::expression<double>();
 261         exprtk_expression_->register_symbol_table(*exprtk_unknown_symbol_table_);
 262         exprtk_expression_->register_symbol_table(*exprtk_symbol_table_);
 263
 264         exprtk_parser_ = new exprtk::parser<double>();
 265         exprtk_parser_->enable_unknown_symbol_resolver();
 266
 267         if (!exprtk_parser_->compile(expression_.toStdString(), *exprtk_expression_)) {
 268                 set_error_message(tr("Error in expression"));
 269         } else {
 270                 // Resolve unknown scalars to signals and add them to the input signal list
 271                 vector<string> unknowns;
 272                 exprtk_unknown_symbol_table_->get_variable_list(unknowns);
 273                 for (string& unknown : unknowns) {
 274                         signal_data* sig_data = signal_from_name(unknown);
 275                         const shared_ptr<SignalBase> signal = (sig_data) ? (sig_data->sb) : nullptr;
 276                         if (!signal || (!signal->analog_data())) {
 277                                 set_error_message(QString(tr("%1 isn't a valid signal")).arg(
 278                                         QString::fromStdString(unknown)));
 279                         } else
 280                                 sig_data->ref = &(exprtk_unknown_symbol_table_->variable_ref(unknown));
 281                 }
 282         }
 283
 284         if (error_message_.isEmpty()) {
 285                 gen_interrupt_ = false;
 286                 gen_thread_ = std::thread(&MathSignal::generation_proc, this);
 287         }
 288 }
 289
 290 void MathSignal::generate_samples(uint32_t segment_id, const uint64_t start_sample,
 291         const int64_t sample_count)
 292 {
 293         shared_ptr<Analog> analog = dynamic_pointer_cast<Analog>(data_);
 294         shared_ptr<AnalogSegment> segment = analog->analog_segments().at(segment_id);
 295
 296         // Keep the math functions segment IDs in sync
 297         fnc_sig_sample_->current_segment = segment_id;
 298
 299         const double sample_rate = data_->get_samplerate();
 300
 301         exprtk_current_sample_ = start_sample;
 302
 303         float *sample_data = new float[sample_count];
 304
 305         for (int64_t i = 0; i < sample_count; i++) {
 306                 exprtk_current_time_ = exprtk_current_sample_ / sample_rate;
 307
 308                 for (auto& entry : input_signals_) {
 309                         signal_data* sig_data  = &(entry.second);
 310                         update_signal_sample(sig_data, segment_id, exprtk_current_sample_);
 311                 }
 312
 313                 double value = exprtk_expression_->value();
 314                 sample_data[i] = value;
 315                 exprtk_current_sample_ += 1;
 316         }
 317
 318         segment->append_interleaved_samples(sample_data, sample_count, 1);
 319
 320         delete[] sample_data;
 321 }
 322
 323 void MathSignal::generation_proc()
 324 {
 325         uint32_t segment_id = 0;
 326
 327         // Don't do anything until we have a valid sample rate
 328         do {
 329                 if (use_custom_sample_rate_)
 330                         data_->set_samplerate(custom_sample_rate_);
 331                 else
 332                         data_->set_samplerate(session_.get_samplerate());
 333
 334                 if (data_->get_samplerate() == 1) {
 335                         unique_lock<mutex> gen_input_lock(input_mutex_);
 336                         gen_input_cond_.wait(gen_input_lock);
 337                 }
 338         } while ((!gen_interrupt_) && (data_->get_samplerate() == 1));
 339
 340         if (gen_interrupt_)
 341                 return;
 342
 343         shared_ptr<Analog> analog = analog_data();
 344
 345         // Create initial analog segment
 346         shared_ptr<AnalogSegment> output_segment =
 347                 make_shared<AnalogSegment>(*analog.get(), segment_id, analog->get_samplerate());
 348         analog->push_segment(output_segment);
 349
 350         // Create analog samples
 351         do {
 352                 const uint64_t input_sample_count = get_working_sample_count(segment_id);
 353                 const uint64_t output_sample_count = output_segment->get_sample_count();
 354
 355                 const uint64_t samples_to_process =
 356                         (input_sample_count > output_sample_count) ?
 357                         (input_sample_count - output_sample_count) : 0;
 358
 359                 // Process the samples if necessary...
 360                 if (samples_to_process > 0) {
 361                         const uint64_t chunk_sample_count = ChunkLength;
 362
 363                         uint64_t processed_samples = 0;
 364                         do {
 365                                 const uint64_t start_sample = output_sample_count + processed_samples;
 366                                 const uint64_t sample_count =
 367                                         min(samples_to_process - processed_samples,     chunk_sample_count);
 368
 369                                 generate_samples(segment_id, start_sample, sample_count);
 370                                 processed_samples += sample_count;
 371
 372                                 // Notify consumers of this signal's data
 373                                 // TODO Does this work when a conversion is active?
 374                                 samples_added(segment_id, start_sample, start_sample + processed_samples);
 375                         } while (!gen_interrupt_ && (processed_samples < samples_to_process));
 376                 }
 377
 378                 if (samples_to_process == 0) {
 379                         if (segment_id < session_.get_highest_segment_id()) {
 380                                 analog->analog_segments().back()->set_complete();
 381
 382                                 // Process next segment
 383                                 segment_id++;
 384
 385                                 output_segment =
 386                                         make_shared<AnalogSegment>(*analog.get(), segment_id, analog->get_samplerate());
 387                                 analog->push_segment(output_segment);
 388                         } else {
 389                                 // All segments have been processed, wait for more input
 390                                 unique_lock<mutex> gen_input_lock(input_mutex_);
 391                                 gen_input_cond_.wait(gen_input_lock);
 392                         }
 393                 }
 394
 395         } while (!gen_interrupt_);
 396 }
 397
 398 signal_data* MathSignal::signal_from_name(const std::string& name)
 399 {
 400         // Look up signal in the map and if it doesn't exist yet, add it for future use
 401
 402         auto element = input_signals_.find(name);
 403
 404         if (element != input_signals_.end()) {
 405                 return &(element->second);
 406         } else {
 407                 const vector< shared_ptr<SignalBase> > signalbases = session_.signalbases();
 408                 const QString sig_name = QString::fromStdString(name);
 409
 410                 for (const shared_ptr<SignalBase>& sb : signalbases)
 411                         if (sb->name() == sig_name)
 412                                 return &(input_signals_.insert({name, signal_data(sb)}).first->second);
 413         }
 414
 415         return nullptr;
 416 }
 417
 418 void MathSignal::update_signal_sample(signal_data* sig_data, uint32_t segment_id, uint64_t sample_num)
 419 {
 420         assert(sig_data);
 421
 422         // Update the value only if a different sample is requested
 423         if (sig_data->sample_num == sample_num)
 424                 return;
 425
 426         assert(sig_data->sb);
 427         const shared_ptr<pv::data::Analog> analog = sig_data->sb->analog_data();
 428         assert(analog);
 429
 430         assert(segment_id < analog->analog_segments().size());
 431
 432         const shared_ptr<AnalogSegment> segment = analog->analog_segments().at(segment_id);
 433
 434         sig_data->sample_num = sample_num;
 435         sig_data->sample_value = segment->get_sample(sample_num);
 436
 437         // We only have a reference if this signal is used as a scalar,
 438         // if it's used by a function, it's null
 439         if (sig_data->ref)
 440                 *(sig_data->ref) = sig_data->sample_value;
 441 }
 442
 443 void MathSignal::on_capture_state_changed(int state)
 444 {
 445         if (state == Session::Running)
 446                 begin_generation();
 447
 448         if (state == Session::Stopped) {
 449                 shared_ptr<Analog> analog = analog_data();
 450                 analog->analog_segments().back()->set_complete();
 451         }
 452 }
 453
 454 void MathSignal::on_data_received()
 455 {
 456         gen_input_cond_.notify_one();
 457 }
 458
 459 } // namespace data
 460 } // namespace pv