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 <pv/globalsettings.hpp>
  27 #include <pv/session.hpp>
  28 #include <pv/data/analogsegment.hpp>
  29 #include <pv/data/signalbase.hpp>
  30
  31 using std::dynamic_pointer_cast;
  32 using std::make_shared;
  33 using std::min;
  34 using std::unique_lock;
  35
  36 namespace pv {
  37 namespace data {
  38
  39 const int64_t MathSignal::ChunkLength = 256 * 1024;
  40
  41
  42 template<typename T>
  43 struct sig_sample : public exprtk::igeneric_function<T>
  44 {
  45         typedef typename exprtk::igeneric_function<T>::parameter_list_t parameter_list_t;
  46         typedef typename exprtk::igeneric_function<T>::generic_type generic_type;
  47         typedef typename generic_type::scalar_view scalar_t;
  48         typedef typename generic_type::string_view string_t;
  49
  50         sig_sample(MathSignal& owner) :
  51                 exprtk::igeneric_function<T>("ST"),  // Require channel name and sample number
  52                 owner_(owner),
  53                 sig_data(nullptr)
  54         {
  55         }
  56
  57         T operator()(parameter_list_t parameters)
  58         {
  59                 const string_t exprtk_sig_name = string_t(parameters[0]);
  60                 const scalar_t exprtk_sample_num = scalar_t(parameters[1]);
  61
  62                 const std::string str_sig_name = to_str(exprtk_sig_name);
  63                 const double sample_num = exprtk_sample_num();
  64
  65                 if (!sig_data)
  66                         sig_data = owner_.signal_from_name(str_sig_name);
  67
  68                 assert(sig_data);
  69                 owner_.update_signal_sample(sig_data, current_segment, sample_num);
  70
  71                 return T(sig_data->sample_value);
  72         }
  73
  74         MathSignal& owner_;
  75         uint32_t current_segment;
  76         signal_data* sig_data;
  77 };
  78
  79
  80 MathSignal::MathSignal(pv::Session &session) :
  81         SignalBase(nullptr, SignalBase::MathChannel),
  82         session_(session),
  83         use_custom_sample_rate_(false),
  84         use_custom_sample_count_(false),
  85         expression_(""),
  86         error_message_(""),
  87         exprtk_unknown_symbol_table_(nullptr),
  88         exprtk_symbol_table_(nullptr),
  89         exprtk_expression_(nullptr),
  90         exprtk_parser_(nullptr),
  91         fnc_sig_sample_(nullptr)
  92 {
  93         set_name(QString(tr("Math%1")).arg(session_.get_next_signal_index(MathChannel)));
  94
  95         shared_ptr<Analog> data(new data::Analog());
  96         set_data(data);
  97
  98         connect(&session_, SIGNAL(capture_state_changed(int)),
  99                 this, SLOT(on_capture_state_changed(int)));
 100         connect(&session_, SIGNAL(data_received()),
 101                 this, SLOT(on_data_received()));
 102
 103         expression_ = "sin(2 * pi * t) + cos(t / 2 * pi)";
 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                                 const uint32_t last_segment = (a->analog_segments().size() - 1);
 184                                 if (segment_id > last_segment)
 185                                         continue;
 186                                 const shared_ptr<AnalogSegment> segment = a->analog_segments()[segment_id];
 187                                 result = min(result, (int64_t)segment->get_sample_count());
 188                         }
 189                 } else
 190                         result = session_.get_segment_sample_count(segment_id);
 191         }
 192
 193         return result;
 194 }
 195
 196 void MathSignal::reset_generation()
 197 {
 198         if (gen_thread_.joinable()) {
 199                 gen_interrupt_ = true;
 200                 gen_input_cond_.notify_one();
 201                 gen_thread_.join();
 202         }
 203
 204         data_->clear();
 205         input_signals_.clear();
 206
 207         if (exprtk_parser_) {
 208                 delete exprtk_parser_;
 209                 exprtk_parser_ = nullptr;
 210         }
 211
 212         if (exprtk_expression_) {
 213                 delete exprtk_expression_;
 214                 exprtk_expression_ = nullptr;
 215         }
 216
 217         if (exprtk_symbol_table_) {
 218                 delete exprtk_symbol_table_;
 219                 exprtk_symbol_table_ = nullptr;
 220         }
 221
 222         if (exprtk_unknown_symbol_table_) {
 223                 delete exprtk_unknown_symbol_table_;
 224                 exprtk_unknown_symbol_table_ = nullptr;
 225         }
 226
 227         if (fnc_sig_sample_) {
 228                 delete fnc_sig_sample_;
 229                 fnc_sig_sample_ = nullptr;
 230         }
 231
 232         if (!error_message_.isEmpty()) {
 233                 error_message_ = QString();
 234                 // TODO Emulate noquote()
 235                 qDebug().nospace() << name() << ": Error cleared";
 236         }
 237 }
 238
 239 void MathSignal::begin_generation()
 240 {
 241         reset_generation();
 242
 243         if (expression_.isEmpty()) {
 244                 set_error_message(tr("No expression defined, nothing to do"));
 245                 return;
 246         }
 247
 248         fnc_sig_sample_ = new sig_sample<double>(*this);
 249
 250         exprtk_unknown_symbol_table_ = new exprtk::symbol_table<double>();
 251
 252         exprtk_symbol_table_ = new exprtk::symbol_table<double>();
 253         exprtk_symbol_table_->add_function("sig_sample", *fnc_sig_sample_);
 254         exprtk_symbol_table_->add_variable("t", exprtk_current_time_);
 255         exprtk_symbol_table_->add_variable("s", exprtk_current_sample_);
 256         exprtk_symbol_table_->add_constants();
 257
 258         exprtk_expression_ = new exprtk::expression<double>();
 259         exprtk_expression_->register_symbol_table(*exprtk_unknown_symbol_table_);
 260         exprtk_expression_->register_symbol_table(*exprtk_symbol_table_);
 261
 262         exprtk_parser_ = new exprtk::parser<double>();
 263         exprtk_parser_->enable_unknown_symbol_resolver();
 264
 265         if (!exprtk_parser_->compile(expression_.toStdString(), *exprtk_expression_)) {
 266                 set_error_message(tr("Error in expression"));
 267         } else {
 268                 // Resolve unknown scalars to signals and add them to the input signal list
 269                 vector<string> unknowns;
 270                 exprtk_unknown_symbol_table_->get_variable_list(unknowns);
 271                 for (string& unknown : unknowns) {
 272                         signal_data* sig_data = signal_from_name(unknown);
 273                         const shared_ptr<SignalBase> signal = (sig_data) ? (sig_data->sb) : nullptr;
 274                         if (!signal || (!signal->analog_data())) {
 275                                 set_error_message(QString(tr("%1 isn't a valid signal")).arg(
 276                                         QString::fromStdString(unknown)));
 277                         } else
 278                                 sig_data->ref = &(exprtk_unknown_symbol_table_->variable_ref(unknown));
 279                 }
 280         }
 281
 282         if (error_message_.isEmpty()) {
 283                 gen_interrupt_ = false;
 284                 gen_thread_ = std::thread(&MathSignal::generation_proc, this);
 285         }
 286 }
 287
 288 void MathSignal::generate_samples(uint32_t segment_id, const uint64_t start_sample,
 289         const int64_t sample_count)
 290 {
 291         shared_ptr<Analog> analog = dynamic_pointer_cast<Analog>(data_);
 292         shared_ptr<AnalogSegment> segment = analog->analog_segments().at(segment_id);
 293
 294         // Keep the math functions segment IDs in sync
 295         fnc_sig_sample_->current_segment = segment_id;
 296
 297         const double sample_rate = data_->get_samplerate();
 298
 299         exprtk_current_sample_ = start_sample;
 300
 301         float *sample_data = new float[sample_count];
 302
 303         for (int64_t i = 0; i < sample_count; i++) {
 304                 exprtk_current_time_ = exprtk_current_sample_ / sample_rate;
 305
 306                 for (auto& entry : input_signals_) {
 307                         signal_data* sig_data  = &(entry.second);
 308                         update_signal_sample(sig_data, segment_id, exprtk_current_sample_);
 309                 }
 310
 311                 double value = exprtk_expression_->value();
 312                 sample_data[i] = value;
 313                 exprtk_current_sample_ += 1;
 314         }
 315
 316         segment->append_interleaved_samples(sample_data, sample_count, 1);
 317
 318         delete[] sample_data;
 319 }
 320
 321 void MathSignal::generation_proc()
 322 {
 323         uint32_t segment_id = 0;
 324
 325         // Don't do anything until we have a valid sample rate
 326         do {
 327                 if (use_custom_sample_rate_)
 328                         data_->set_samplerate(custom_sample_rate_);
 329                 else
 330                         data_->set_samplerate(session_.get_samplerate());
 331
 332                 if (data_->get_samplerate() == 1) {
 333                         unique_lock<mutex> gen_input_lock(input_mutex_);
 334                         gen_input_cond_.wait(gen_input_lock);
 335                 }
 336         } while ((!gen_interrupt_) && (data_->get_samplerate() == 1));
 337
 338         if (gen_interrupt_)
 339                 return;
 340
 341         shared_ptr<Analog> analog = dynamic_pointer_cast<Analog>(data_);
 342
 343         // Create initial analog segment
 344         shared_ptr<AnalogSegment> output_segment =
 345                 make_shared<AnalogSegment>(*analog.get(), segment_id, analog->get_samplerate());
 346         analog->push_segment(output_segment);
 347
 348         // Create analog samples
 349         do {
 350                 const uint64_t input_sample_count = get_working_sample_count(segment_id);
 351                 const uint64_t output_sample_count = output_segment->get_sample_count();
 352
 353                 const uint64_t samples_to_process =
 354                         (input_sample_count > output_sample_count) ?
 355                         (input_sample_count - output_sample_count) : 0;
 356
 357                 // Process the samples if necessary...
 358                 if (samples_to_process > 0) {
 359                         const uint64_t chunk_sample_count = ChunkLength;
 360
 361                         uint64_t processed_samples = 0;
 362                         do {
 363                                 const uint64_t start_sample = output_sample_count + processed_samples;
 364                                 const uint64_t sample_count =
 365                                         min(samples_to_process - processed_samples,     chunk_sample_count);
 366
 367                                 generate_samples(segment_id, start_sample, sample_count);
 368                                 processed_samples += sample_count;
 369
 370                                 // Notify consumers of this signal's data
 371                                 // TODO Does this work when a conversion is active?
 372                                 samples_added(segment_id, start_sample, start_sample + processed_samples);
 373                         } while (!gen_interrupt_ && (processed_samples < samples_to_process));
 374                 }
 375
 376                 if (samples_to_process == 0) {
 377                         if (segment_id < session_.get_highest_segment_id()) {
 378                                 // Process next segment
 379                                 segment_id++;
 380
 381                                 output_segment =
 382                                         make_shared<AnalogSegment>(*analog.get(), segment_id, analog->get_samplerate());
 383                                 analog->push_segment(output_segment);
 384                         } else {
 385                                 // All segments have been processed, wait for more input
 386                                 unique_lock<mutex> gen_input_lock(input_mutex_);
 387                                 gen_input_cond_.wait(gen_input_lock);
 388                         }
 389                 }
 390
 391         } while (!gen_interrupt_);
 392 }
 393
 394 signal_data* MathSignal::signal_from_name(const std::string& name)
 395 {
 396         // Look up signal in the map and if it doesn't exist yet, add it for future use
 397
 398         auto element = input_signals_.find(name);
 399
 400         if (element != input_signals_.end()) {
 401                 return &(element->second);
 402         } else {
 403                 const vector< shared_ptr<SignalBase> > signalbases = session_.signalbases();
 404                 const QString sig_name = QString::fromStdString(name);
 405
 406                 for (const shared_ptr<SignalBase>& sb : signalbases)
 407                         if (sb->name() == sig_name)
 408                                 return &(input_signals_.insert({name, signal_data(sb)}).first->second);
 409         }
 410
 411         return nullptr;
 412 }
 413
 414 void MathSignal::update_signal_sample(signal_data* sig_data, uint32_t segment_id, uint64_t sample_num)
 415 {
 416         assert(sig_data);
 417
 418         // Update the value only if a different sample is requested
 419         if (sig_data->sample_num == sample_num)
 420                 return;
 421
 422         assert(sig_data->sb);
 423         const shared_ptr<pv::data::Analog> analog = sig_data->sb->analog_data();
 424         assert(analog);
 425
 426         assert(segment_id < analog->analog_segments().size());
 427
 428         const shared_ptr<AnalogSegment> segment = analog->analog_segments().at(segment_id);
 429
 430         sig_data->sample_num = sample_num;
 431         sig_data->sample_value = segment->get_sample(sample_num);
 432
 433         // We only have a reference if this signal is used as a scalar,
 434         // if it's used by a function, it's null
 435         if (sig_data->ref)
 436                 *(sig_data->ref) = sig_data->sample_value;
 437 }
 438
 439 void MathSignal::on_capture_state_changed(int state)
 440 {
 441         if (state == Session::Running)
 442                 begin_generation();
 443 }
 444
 445 void MathSignal::on_data_received()
 446 {
 447         gen_input_cond_.notify_one();
 448 }
 449
 450 } // namespace data
 451 } // namespace pv