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
 106 MathSignal::~MathSignal()
 107 {
 108         reset_generation();
 109
 110         if (fnc_sig_sample_)
 111                 delete fnc_sig_sample_;
 112 }
 113
 114 void MathSignal::save_settings(QSettings &settings) const
 115 {
 116         settings.setValue("expression", expression_);
 117
 118         settings.setValue("custom_sample_rate", (qulonglong)custom_sample_rate_);
 119         settings.setValue("custom_sample_count", (qulonglong)custom_sample_count_);
 120         settings.setValue("use_custom_sample_rate", use_custom_sample_rate_);
 121         settings.setValue("use_custom_sample_count", use_custom_sample_count_);
 122 }
 123
 124 void MathSignal::restore_settings(QSettings &settings)
 125 {
 126         if (settings.contains("expression"))
 127                 expression_ = settings.value("expression").toString();
 128
 129         if (settings.contains("custom_sample_rate"))
 130                 custom_sample_rate_ = settings.value("custom_sample_rate").toULongLong();
 131
 132         if (settings.contains("custom_sample_count"))
 133                 custom_sample_count_ = settings.value("custom_sample_count").toULongLong();
 134
 135         if (settings.contains("use_custom_sample_rate"))
 136                 use_custom_sample_rate_ = settings.value("use_custom_sample_rate").toBool();
 137
 138         if (settings.contains("use_custom_sample_count"))
 139                 use_custom_sample_count_ = settings.value("use_custom_sample_count").toBool();
 140 }
 141
 142 QString MathSignal::error_message() const
 143 {
 144         return error_message_;
 145 }
 146
 147 QString MathSignal::get_expression() const
 148 {
 149         return expression_;
 150 }
 151
 152 void MathSignal::set_expression(QString expression)
 153 {
 154         expression_ = expression;
 155
 156         begin_generation();
 157 }
 158
 159 void MathSignal::set_error_message(QString msg)
 160 {
 161         error_message_ = msg;
 162         // TODO Emulate noquote()
 163         qDebug().nospace() << name() << ": " << msg << "(Expression: '" << expression_ << "')";
 164 }
 165
 166 uint64_t MathSignal::get_working_sample_count(uint32_t segment_id) const
 167 {
 168         // The working sample count is the highest sample number for
 169         // which all used signals have data available, so go through all
 170         // channels and use the lowest overall sample count of the segment
 171
 172         int64_t result = std::numeric_limits<int64_t>::max();
 173
 174         if (use_custom_sample_count_)
 175                 // A custom sample count implies that only one segment will be created
 176                 result = (segment_id == 0) ? custom_sample_count_ : 0;
 177         else {
 178                 if (input_signals_.size() > 0) {
 179                         for (auto input_signal : input_signals_) {
 180                                 const shared_ptr<SignalBase>& sb = input_signal.second.sb;
 181
 182                                 shared_ptr<Analog> a = sb->analog_data();
 183                                 auto analog_segments = a->analog_segments();
 184
 185                                 if (analog_segments.size() == 0) {
 186                                         result = 0;
 187                                         continue;
 188                                 }
 189
 190                                 const uint32_t highest_segment_id = (analog_segments.size() - 1);
 191                                 if (segment_id > highest_segment_id)
 192                                         continue;
 193
 194                                 const shared_ptr<AnalogSegment> segment = analog_segments.at(segment_id);
 195                                 result = min(result, (int64_t)segment->get_sample_count());
 196                         }
 197                 } else
 198                         result = session_.get_segment_sample_count(segment_id);
 199         }
 200
 201         return result;
 202 }
 203
 204 void MathSignal::update_completeness(uint32_t segment_id)
 205 {
 206         bool output_complete = true;
 207
 208         if (input_signals_.size() > 0) {
 209                 for (auto input_signal : input_signals_) {
 210                         const shared_ptr<SignalBase>& sb = input_signal.second.sb;
 211
 212                         shared_ptr<Analog> a = sb->analog_data();
 213                         auto analog_segments = a->analog_segments();
 214
 215                         if (analog_segments.size() == 0) {
 216                                 output_complete = false;
 217                                 continue;
 218                         }
 219
 220                         const uint32_t highest_segment_id = (analog_segments.size() - 1);
 221                         if (segment_id > highest_segment_id) {
 222                                 output_complete = false;
 223                                 continue;
 224                         }
 225
 226                         const shared_ptr<AnalogSegment> segment = analog_segments.at(segment_id);
 227                         if (!segment->is_complete())
 228                                 output_complete = false;
 229                 }
 230         }
 231
 232         if (output_complete)
 233                 analog_data()->analog_segments().at(segment_id)->set_complete();
 234 }
 235
 236 void MathSignal::reset_generation()
 237 {
 238         if (gen_thread_.joinable()) {
 239                 gen_interrupt_ = true;
 240                 gen_input_cond_.notify_one();
 241                 gen_thread_.join();
 242         }
 243
 244         data_->clear();
 245         input_signals_.clear();
 246
 247         if (exprtk_parser_) {
 248                 delete exprtk_parser_;
 249                 exprtk_parser_ = nullptr;
 250         }
 251
 252         if (exprtk_expression_) {
 253                 delete exprtk_expression_;
 254                 exprtk_expression_ = nullptr;
 255         }
 256
 257         if (exprtk_symbol_table_) {
 258                 delete exprtk_symbol_table_;
 259                 exprtk_symbol_table_ = nullptr;
 260         }
 261
 262         if (exprtk_unknown_symbol_table_) {
 263                 delete exprtk_unknown_symbol_table_;
 264                 exprtk_unknown_symbol_table_ = nullptr;
 265         }
 266
 267         if (fnc_sig_sample_) {
 268                 delete fnc_sig_sample_;
 269                 fnc_sig_sample_ = nullptr;
 270         }
 271
 272         if (!error_message_.isEmpty()) {
 273                 error_message_ = QString();
 274                 // TODO Emulate noquote()
 275                 qDebug().nospace() << name() << ": Error cleared";
 276         }
 277 }
 278
 279 void MathSignal::begin_generation()
 280 {
 281         reset_generation();
 282
 283         if (expression_.isEmpty()) {
 284                 set_error_message(tr("No expression defined, nothing to do"));
 285                 return;
 286         }
 287
 288         fnc_sig_sample_ = new sig_sample<double>(*this);
 289
 290         exprtk_unknown_symbol_table_ = new exprtk::symbol_table<double>();
 291
 292         exprtk_symbol_table_ = new exprtk::symbol_table<double>();
 293         exprtk_symbol_table_->add_function("sig_sample", *fnc_sig_sample_);
 294         exprtk_symbol_table_->add_variable("t", exprtk_current_time_);
 295         exprtk_symbol_table_->add_variable("s", exprtk_current_sample_);
 296         exprtk_symbol_table_->add_constants();
 297
 298         exprtk_expression_ = new exprtk::expression<double>();
 299         exprtk_expression_->register_symbol_table(*exprtk_unknown_symbol_table_);
 300         exprtk_expression_->register_symbol_table(*exprtk_symbol_table_);
 301
 302         exprtk_parser_ = new exprtk::parser<double>();
 303         exprtk_parser_->enable_unknown_symbol_resolver();
 304
 305         if (!exprtk_parser_->compile(expression_.toStdString(), *exprtk_expression_)) {
 306                 set_error_message(tr("Error in expression"));
 307         } else {
 308                 // Resolve unknown scalars to signals and add them to the input signal list
 309                 vector<string> unknowns;
 310                 exprtk_unknown_symbol_table_->get_variable_list(unknowns);
 311                 for (string& unknown : unknowns) {
 312                         signal_data* sig_data = signal_from_name(unknown);
 313                         const shared_ptr<SignalBase> signal = (sig_data) ? (sig_data->sb) : nullptr;
 314                         if (!signal || (!signal->analog_data())) {
 315                                 set_error_message(QString(tr("%1 isn't a valid analog signal")).arg(
 316                                         QString::fromStdString(unknown)));
 317                         } else
 318                                 sig_data->ref = &(exprtk_unknown_symbol_table_->variable_ref(unknown));
 319                 }
 320         }
 321
 322         if (error_message_.isEmpty()) {
 323                 gen_interrupt_ = false;
 324                 gen_thread_ = std::thread(&MathSignal::generation_proc, this);
 325         }
 326 }
 327
 328 void MathSignal::generate_samples(uint32_t segment_id, const uint64_t start_sample,
 329         const int64_t sample_count)
 330 {
 331         shared_ptr<Analog> analog = dynamic_pointer_cast<Analog>(data_);
 332         shared_ptr<AnalogSegment> segment = analog->analog_segments().at(segment_id);
 333
 334         // Keep the math functions segment IDs in sync
 335         fnc_sig_sample_->current_segment = segment_id;
 336
 337         const double sample_rate = data_->get_samplerate();
 338
 339         exprtk_current_sample_ = start_sample;
 340
 341         float *sample_data = new float[sample_count];
 342
 343         for (int64_t i = 0; i < sample_count; i++) {
 344                 exprtk_current_time_ = exprtk_current_sample_ / sample_rate;
 345
 346                 for (auto& entry : input_signals_) {
 347                         signal_data* sig_data  = &(entry.second);
 348                         update_signal_sample(sig_data, segment_id, exprtk_current_sample_);
 349                 }
 350
 351                 double value = exprtk_expression_->value();
 352                 sample_data[i] = value;
 353                 exprtk_current_sample_ += 1;
 354         }
 355
 356         segment->append_interleaved_samples(sample_data, sample_count, 1);
 357
 358         delete[] sample_data;
 359 }
 360
 361 void MathSignal::generation_proc()
 362 {
 363         uint32_t segment_id = 0;
 364
 365         // Don't do anything until we have a valid sample rate
 366         do {
 367                 if (use_custom_sample_rate_)
 368                         data_->set_samplerate(custom_sample_rate_);
 369                 else
 370                         data_->set_samplerate(session_.get_samplerate());
 371
 372                 if (data_->get_samplerate() == 1) {
 373                         unique_lock<mutex> gen_input_lock(input_mutex_);
 374                         gen_input_cond_.wait(gen_input_lock);
 375                 }
 376         } while ((!gen_interrupt_) && (data_->get_samplerate() == 1));
 377
 378         if (gen_interrupt_)
 379                 return;
 380
 381         shared_ptr<Analog> analog = analog_data();
 382
 383         // Create initial analog segment
 384         shared_ptr<AnalogSegment> output_segment =
 385                 make_shared<AnalogSegment>(*analog.get(), segment_id, analog->get_samplerate());
 386         analog->push_segment(output_segment);
 387
 388         // Create analog samples
 389         do {
 390                 const uint64_t input_sample_count = get_working_sample_count(segment_id);
 391                 const uint64_t output_sample_count = output_segment->get_sample_count();
 392
 393                 const uint64_t samples_to_process =
 394                         (input_sample_count > output_sample_count) ?
 395                         (input_sample_count - output_sample_count) : 0;
 396
 397                 // Process the samples if necessary...
 398                 if (samples_to_process > 0) {
 399                         const uint64_t chunk_sample_count = ChunkLength;
 400
 401                         uint64_t processed_samples = 0;
 402                         do {
 403                                 const uint64_t start_sample = output_sample_count + processed_samples;
 404                                 const uint64_t sample_count =
 405                                         min(samples_to_process - processed_samples,     chunk_sample_count);
 406
 407                                 generate_samples(segment_id, start_sample, sample_count);
 408                                 processed_samples += sample_count;
 409
 410                                 // Notify consumers of this signal's data
 411                                 // TODO Does this work when a conversion is active?
 412                                 samples_added(segment_id, start_sample, start_sample + processed_samples);
 413                         } while (!gen_interrupt_ && (processed_samples < samples_to_process));
 414                 }
 415
 416                 if (samples_to_process == 0) {
 417                         update_completeness(segment_id);
 418
 419                         if (segment_id < session_.get_highest_segment_id()) {
 420                                 // Process next segment
 421                                 segment_id++;
 422
 423                                 output_segment =
 424                                         make_shared<AnalogSegment>(*analog.get(), segment_id, analog->get_samplerate());
 425                                 analog->push_segment(output_segment);
 426                         } else {
 427                                 // All segments have been processed, wait for more input
 428                                 unique_lock<mutex> gen_input_lock(input_mutex_);
 429                                 gen_input_cond_.wait(gen_input_lock);
 430                         }
 431                 }
 432
 433         } while (!gen_interrupt_);
 434 }
 435
 436 signal_data* MathSignal::signal_from_name(const std::string& name)
 437 {
 438         // Look up signal in the map and if it doesn't exist yet, add it for future use
 439
 440         auto element = input_signals_.find(name);
 441
 442         if (element != input_signals_.end()) {
 443                 return &(element->second);
 444         } else {
 445                 const vector< shared_ptr<SignalBase> > signalbases = session_.signalbases();
 446                 const QString sig_name = QString::fromStdString(name);
 447
 448                 for (const shared_ptr<SignalBase>& sb : signalbases)
 449                         if (sb->name() == sig_name) {
 450                                 if (!sb->analog_data())
 451                                         continue;
 452
 453                                 connect(sb->analog_data().get(), SIGNAL(segment_completed()),
 454                                         this, SLOT(on_data_received()));
 455
 456                                 return &(input_signals_.insert({name, signal_data(sb)}).first->second);
 457                         }
 458         }
 459
 460         return nullptr;
 461 }
 462
 463 void MathSignal::update_signal_sample(signal_data* sig_data, uint32_t segment_id, uint64_t sample_num)
 464 {
 465         assert(sig_data);
 466
 467         // Update the value only if a different sample is requested
 468         if (sig_data->sample_num == sample_num)
 469                 return;
 470
 471         assert(sig_data->sb);
 472         const shared_ptr<pv::data::Analog> analog = sig_data->sb->analog_data();
 473         assert(analog);
 474
 475         assert(segment_id < analog->analog_segments().size());
 476
 477         const shared_ptr<AnalogSegment> segment = analog->analog_segments().at(segment_id);
 478
 479         sig_data->sample_num = sample_num;
 480         sig_data->sample_value = segment->get_sample(sample_num);
 481
 482         // We only have a reference if this signal is used as a scalar,
 483         // if it's used by a function, it's null
 484         if (sig_data->ref)
 485                 *(sig_data->ref) = sig_data->sample_value;
 486 }
 487
 488 void MathSignal::on_capture_state_changed(int state)
 489 {
 490         if (state == Session::Running)
 491                 begin_generation();
 492
 493         if (state == Session::Stopped) {
 494                 // If we have input signals, we use those as the indicators
 495                 if (input_signals_.empty()) {
 496                         shared_ptr<Analog> analog = analog_data();
 497                         if (!analog->analog_segments().empty())
 498                                 analog->analog_segments().back()->set_complete();
 499                 }
 500         }
 501 }
 502
 503 void MathSignal::on_data_received()
 504 {
 505         gen_input_cond_.notify_one();
 506 }
 507
 508 } // namespace data
 509 } // namespace pv