Merge branch 'jwmelto-feature/signal_source_interface' into next

docs/changelog.md

@@ -36,6 +36,9 @@ SPDX-FileCopyrightText: 2011-2021 Carles Fernandez-Prades <carles.fernandez@cttc
   asking them to sign the CLA document).
 - Improved handling of change in GNU Radio 3.9 FFT API.
 - Improved handling of the filesystem library.
+- Added an abstract class `SignalSourceInterface` and a common base class
+  `SignalSourceBase`, which allow to remove a lot of duplicated code in Signal
+  Source blocks, and further abstract file-based interfaces behind them.
 - Do not apply clang-tidy fixes to protobuf-generated headers.
 - Refactored private implementation of flow graph connection and disconnection
   for improved source code readability.

src/algorithms/libs/CMakeLists.txt

@@ -31,6 +31,7 @@ set(GNSS_SPLIBS_SOURCES
     item_type_helpers.cc
     pass_through.cc
     short_x2_to_cshort.cc
+    gnss_sdr_string_literals.cc
 )
 
 set(GNSS_SPLIBS_HEADERS
@@ -61,6 +62,7 @@ set(GNSS_SPLIBS_HEADERS
     item_type_helpers.h
     pass_through.h
     short_x2_to_cshort.h
+    gnss_sdr_string_literals.h
 )
 
 if(ENABLE_OPENCL)

src/algorithms/libs/gnss_sdr_string_literals.cc

@@ -0,0 +1,37 @@
+/*!
+ * \file gnss_sdr_string_literals.cc
+ * \brief This file implements the ""s operator for std::string in C++11, and
+ * puts it into the std::string_literals namespace. This is already implemented
+ * in C++14, so this is only compiled when using C++11. The .cc file is required
+ * for avoiding the duplication of symbols.
+ *
+ * \author Carles Fernandez-Prades, 2021. cfernandez(at)cttc.es
+ *
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
+ * This file is part of GNSS-SDR.
+ *
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * -----------------------------------------------------------------------------
+ */
+
+#include "gnss_sdr_string_literals.h"
+
+#if __cplusplus == 201103L
+
+namespace std
+{
+namespace string_literals
+{
+std::string operator"" s(const char* str, std::size_t len)
+{
+    return std::string(str, len);
+};
+}  // namespace string_literals
+}  // namespace std
+
+#endif  // __cplusplus == 201103L

src/algorithms/libs/gnss_sdr_string_literals.h

@@ -0,0 +1,48 @@
+/*!
+ * \file gnss_sdr_string_literals.h
+ * \brief This file implements the ""s operator for std::string in C++11, and
+ * puts it into the std::string_literals namespace. This is already implemented
+ * in C++14, so this is only compiled when using C++11. The .cc file is required
+ * for avoiding the duplication of symbols.
+ *
+ * \author Carles Fernandez-Prades, 2021. cfernandez(at)cttc.es
+ *
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
+ * This file is part of GNSS-SDR.
+ *
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * -----------------------------------------------------------------------------
+ */
+
+#ifndef GNSS_SDR_STRING_LITERALS_H
+#define GNSS_SDR_STRING_LITERALS_H
+
+/** \addtogroup Algorithms_Library
+ * \{ */
+/** \addtogroup Algorithm_libs algorithms_libs
+ * \{ */
+
+#if __cplusplus == 201103L
+
+#include <cstddef>
+#include <string>
+
+namespace std
+{
+namespace string_literals
+{
+std::string operator"" s(const char* str, std::size_t len);
+}  // namespace string_literals
+}  // namespace std
+
+#endif  // __cplusplus == 201103L
+
+/** \} */
+/** \} */
+
+#endif  // GNSS_SDR_STRING_LITERALS_H

src/algorithms/signal_source/adapters/CMakeLists.txt

@@ -92,6 +92,8 @@ endif()
 
 
 set(SIGNAL_SOURCE_ADAPTER_SOURCES
+    signal_source_base.cc
+    file_source_base.cc
     file_signal_source.cc
     multichannel_file_signal_source.cc
     gen_signal_source.cc
@@ -106,6 +108,8 @@ set(SIGNAL_SOURCE_ADAPTER_SOURCES
 )
 
 set(SIGNAL_SOURCE_ADAPTER_HEADERS
+    signal_source_base.h
+    file_source_base.h
     file_signal_source.h
     multichannel_file_signal_source.h
     gen_signal_source.h
@@ -156,6 +160,7 @@ target_link_libraries(signal_source_adapters
         Gnuradio::blocks
         signal_source_gr_blocks
     PRIVATE
+        algorithms_libs
         gnss_sdr_flags
         core_system_parameters
         Glog::glog

src/algorithms/signal_source/adapters/ad9361_fpga_signal_source.cc

@@ -25,6 +25,7 @@
 #include "ad9361_manager.h"
 #include "configuration_interface.h"
 #include "gnss_sdr_flags.h"
+#include "gnss_sdr_string_literals.h"
 #include "uio_fpga.h"
 #include <glog/logging.h>
 #include <iio.h>
@@ -42,9 +43,12 @@
 #include <vector>
 
 
+using namespace std::string_literals;
+
 Ad9361FpgaSignalSource::Ad9361FpgaSignalSource(const ConfigurationInterface *configuration,
     const std::string &role, unsigned int in_stream, unsigned int out_stream,
-    Concurrent_Queue<pmt::pmt_t> *queue __attribute__((unused))) : role_(role), in_stream_(in_stream), out_stream_(out_stream)
+    Concurrent_Queue<pmt::pmt_t> *queue __attribute__((unused)))
+    : SignalSourceBase(configuration, role, "Ad9361_Fpga_Signal_Source"s), in_stream_(in_stream), out_stream_(out_stream)
 {
     const std::string default_gain_mode("slow_attack");
     const double default_tx_attenuation_db = -10.0;

src/algorithms/signal_source/adapters/ad9361_fpga_signal_source.h

@@ -23,6 +23,7 @@
 #include "fpga_dynamic_bit_selection.h"
 #include "fpga_switch.h"
 #include "gnss_block_interface.h"
+#include "signal_source_base.h"
 #include <pmt/pmt.h>
 #include <cstdint>
 #include <memory>
@@ -39,7 +40,7 @@
 
 class ConfigurationInterface;
 
-class Ad9361FpgaSignalSource : public GNSSBlockInterface
+class Ad9361FpgaSignalSource : public SignalSourceBase
 {
 public:
     Ad9361FpgaSignalSource(const ConfigurationInterface *configuration,
@@ -50,19 +51,6 @@ public:
 
     void start() override;
 
-    inline std::string role() override
-    {
-        return role_;
-    }
-
-    /*!
-     * \brief Returns "Ad9361_Fpga_Signal_Source"
-     */
-    inline std::string implementation() override
-    {
-        return "Ad9361_Fpga_Signal_Source";
-    }
-
     inline size_t item_size() override
     {
         return item_size_;
@@ -100,8 +88,6 @@ private:
     std::shared_ptr<Fpga_dynamic_bit_selection> dynamic_bit_selection_fpga;
     std::shared_ptr<Fpga_buffer_monitor> buffer_monitor_fpga;
 
-    std::string role_;
-
     // Front-end settings
     std::string gain_mode_rx1_;
     std::string gain_mode_rx2_;

src/algorithms/signal_source/adapters/custom_udp_signal_source.cc

@@ -17,13 +17,17 @@
 
 #include "custom_udp_signal_source.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 #include <iostream>
 
 
+using namespace std::string_literals;
+
 CustomUDPSignalSource::CustomUDPSignalSource(const ConfigurationInterface* configuration,
     const std::string& role, unsigned int in_stream, unsigned int out_stream,
-    Concurrent_Queue<pmt::pmt_t>* queue __attribute__((unused))) : role_(role), in_stream_(in_stream), out_stream_(out_stream)
+    Concurrent_Queue<pmt::pmt_t>* queue __attribute__((unused)))
+    : SignalSourceBase(configuration, role, "Custom_UDP_Signal_Source"s), in_stream_(in_stream), out_stream_(out_stream)
 {
     // DUMP PARAMETERS
     const std::string default_dump_file("./data/signal_source.dat");

src/algorithms/signal_source/adapters/custom_udp_signal_source.h

@@ -19,8 +19,8 @@
 #define GNSS_SDR_CUSTOM_UDP_SIGNAL_SOURCE_H
 
 #include "concurrent_queue.h"
-#include "gnss_block_interface.h"
 #include "gr_complex_ip_packet_source.h"
+#include "signal_source_base.h"
 #include <gnuradio/blocks/file_sink.h>
 #include <gnuradio/blocks/null_sink.h>
 #include <pmt/pmt.h>
@@ -40,7 +40,7 @@ class ConfigurationInterface;
  * \brief This class reads from UDP packets, which streams interleaved
  * I/Q samples over a network.
  */
-class CustomUDPSignalSource : public GNSSBlockInterface
+class CustomUDPSignalSource : public SignalSourceBase
 {
 public:
     CustomUDPSignalSource(const ConfigurationInterface* configuration,
@@ -49,19 +49,6 @@ public:
 
     ~CustomUDPSignalSource() = default;
 
-    inline std::string role() override
-    {
-        return role_;
-    }
-
-    /*!
-     * \brief Returns "Custom_UDP_Signal_Source"
-     */
-    inline std::string implementation() override
-    {
-        return "Custom_UDP_Signal_Source";
-    }
-
     inline size_t item_size() override
     {
         return item_size_;
@@ -78,7 +65,6 @@ private:
     std::vector<gnss_shared_ptr<gr::block>> null_sinks_;
     std::vector<gnss_shared_ptr<gr::block>> file_sink_;
 
-    std::string role_;
     std::string item_type_;
     std::string dump_filename_;
 

src/algorithms/signal_source/adapters/file_signal_source.cc

@@ -10,343 +10,29 @@
  * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
  * This file is part of GNSS-SDR.
  *
- * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
  * -----------------------------------------------------------------------------
  */
 
 #include "file_signal_source.h"
-#include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
-#include "gnss_sdr_flags.h"
-#include "gnss_sdr_valve.h"
 #include <glog/logging.h>
-#include <exception>
-#include <fstream>
-#include <iomanip>
-#include <iostream>  // for std::cerr
-#include <utility>
 
+using namespace std::string_literals;
 
-FileSignalSource::FileSignalSource(const ConfigurationInterface* configuration,
+FileSignalSource::FileSignalSource(ConfigurationInterface const* configuration,
-    const std::string& role, unsigned int in_streams, unsigned int out_streams,
+    std::string const& role, unsigned int in_streams, unsigned int out_streams,
-    Concurrent_Queue<pmt::pmt_t>* queue) : role_(role), in_streams_(in_streams), out_streams_(out_streams)
+    Concurrent_Queue<pmt::pmt_t>* queue)
+    : FileSourceBase(configuration, role, "File_Signal_Source"s, queue, "short"s)
 {
-    const std::string default_filename("./example_capture.dat");
+    if (in_streams > 0)
-    const std::string default_item_type("short");
-    const std::string default_dump_filename("./my_capture.dat");
-
-    const double default_seconds_to_skip = 0.0;
-
-    samples_ = configuration->property(role + ".samples", static_cast<uint64_t>(0));
-    sampling_frequency_ = configuration->property(role + ".sampling_frequency", static_cast<int64_t>(0));
-    filename_ = configuration->property(role + ".filename", default_filename);
-
-    // override value with commandline flag, if present
-    if (FLAGS_signal_source != "-")
-        {
-            filename_ = FLAGS_signal_source;
-        }
-    if (FLAGS_s != "-")
-        {
-            filename_ = FLAGS_s;
-        }
-
-    item_type_ = configuration->property(role + ".item_type", default_item_type);
-    repeat_ = configuration->property(role + ".repeat", false);
-    dump_ = configuration->property(role + ".dump", false);
-    dump_filename_ = configuration->property(role + ".dump_filename", default_dump_filename);
-    enable_throttle_control_ = configuration->property(role + ".enable_throttle_control", false);
-
-    const double seconds_to_skip = configuration->property(role + ".seconds_to_skip", default_seconds_to_skip);
-    const size_t header_size = configuration->property(role + ".header_size", 0);
-    int64_t samples_to_skip = 0;
-
-    bool is_complex = false;
-
-    if (item_type_ == "gr_complex")
-        {
-            item_size_ = sizeof(gr_complex);
-        }
-    else if (item_type_ == "float")
-        {
-            item_size_ = sizeof(float);
-        }
-    else if (item_type_ == "short")
-        {
-            item_size_ = sizeof(int16_t);
-        }
-    else if (item_type_ == "ishort")
-        {
-            item_size_ = sizeof(int16_t);
-            is_complex = true;
-        }
-    else if (item_type_ == "byte")
-        {
-            item_size_ = sizeof(int8_t);
-        }
-    else if (item_type_ == "ibyte")
-        {
-            item_size_ = sizeof(int8_t);
-            is_complex = true;
-        }
-    else
-        {
-            LOG(WARNING) << item_type_
-                         << " unrecognized item type. Using gr_complex.";
-            item_size_ = sizeof(gr_complex);
-        }
-    try
-        {
-            file_source_ = gr::blocks::file_source::make(item_size_, filename_.c_str(), repeat_);
-
-            if (seconds_to_skip > 0)
-                {
-                    samples_to_skip = static_cast<int64_t>(seconds_to_skip * sampling_frequency_);
-
-                    if (is_complex)
-                        {
-                            samples_to_skip *= 2;
-                        }
-                }
-            if (header_size > 0)
-                {
-                    samples_to_skip += header_size;
-                }
-
-            if (samples_to_skip > 0)
-                {
-                    LOG(INFO) << "Skipping " << samples_to_skip << " samples of the input file";
-                    if (not file_source_->seek(samples_to_skip, SEEK_SET))
-                        {
-                            LOG(INFO) << "Error skipping bytes!";
-                        }
-                }
-        }
-    catch (const std::exception& e)
-        {
-            if (filename_ == default_filename)
-                {
-                    std::cerr
-                        << "The configuration file has not been found.\n"
-                        << "Please create a configuration file based on the examples at the 'conf/' folder\n"
-                        << "and then generate your own GNSS Software Defined Receiver by doing:\n"
-                        << "$ gnss-sdr --config_file=/path/to/my_GNSS_SDR_configuration.conf\n";
-                }
-            else
-                {
-                    std::cerr
-                        << "The receiver was configured to work with a file signal source\n"
-                        << "but the specified file is unreachable by GNSS-SDR.\n"
-                        << "Please modify your configuration file\n"
-                        << "and point SignalSource.filename to a valid raw data file. Then:\n"
-                        << "$ gnss-sdr --config_file=/path/to/my_GNSS_SDR_configuration.conf\n"
-                        << "Examples of configuration files available at:\n"
-                        << GNSSSDR_INSTALL_DIR "/share/gnss-sdr/conf/\n";
-                }
-
-            LOG(INFO) << "file_signal_source: Unable to open the samples file "
-                      << filename_.c_str() << ", exiting the program.";
-            throw(e);
-        }
-
-    DLOG(INFO) << "file_source(" << file_source_->unique_id() << ")";
-
-    if (samples_ == 0)  // read all file
-        {
-            /*!
-             * BUG workaround: The GNU Radio file source does not stop the receiver after reaching the End of File.
-             * A possible solution is to compute the file length in samples using file size, excluding the last 100 milliseconds, and enable always the
-             * valve block
-             */
-            std::ifstream file(filename_.c_str(), std::ios::in | std::ios::binary | std::ios::ate);
-            std::ifstream::pos_type size;
-
-            if (file.is_open())
-                {
-                    size = file.tellg();
-                    DLOG(INFO) << "Total samples in the file= " << floor(static_cast<double>(size) / static_cast<double>(item_size_));
-                }
-            else
-                {
-                    std::cout << "file_signal_source: Unable to open the samples file " << filename_.c_str() << '\n';
-                    LOG(ERROR) << "file_signal_source: Unable to open the samples file " << filename_.c_str();
-                }
-            std::streamsize ss = std::cout.precision();
-            std::cout << std::setprecision(16);
-            std::cout << "Processing file " << filename_ << ", which contains " << static_cast<double>(size) << " [bytes]\n";
-            std::cout.precision(ss);
-
-            if (size > 0)
-                {
-                    const int64_t bytes_to_skip = samples_to_skip * item_size_;
-                    const int64_t bytes_to_process = static_cast<int64_t>(size) - bytes_to_skip;
-                    samples_ = floor(static_cast<double>(bytes_to_process) / static_cast<double>(item_size_) - ceil(0.002 * static_cast<double>(sampling_frequency_)));  // process all the samples available in the file excluding at least the last 1 ms
-                }
-        }
-
-    CHECK(samples_ > 0) << "File does not contain enough samples to process.";
-    double signal_duration_s = static_cast<double>(samples_) * (1 / static_cast<double>(sampling_frequency_));
-
-    if (is_complex)
-        {
-            signal_duration_s /= 2.0;
-        }
-
-    DLOG(INFO) << "Total number samples to be processed= " << samples_ << " GNSS signal duration= " << signal_duration_s << " [s]";
-    std::cout << "GNSS signal recorded time to be processed: " << signal_duration_s << " [s]\n";
-
-    valve_ = gnss_sdr_make_valve(item_size_, samples_, queue);
-    DLOG(INFO) << "valve(" << valve_->unique_id() << ")";
-
-    if (dump_)
-        {
-            sink_ = gr::blocks::file_sink::make(item_size_, dump_filename_.c_str());
-            DLOG(INFO) << "file_sink(" << sink_->unique_id() << ")";
-        }
-
-    if (enable_throttle_control_)
-        {
-            throttle_ = gr::blocks::throttle::make(item_size_, sampling_frequency_);
-        }
-
-    DLOG(INFO) << "File source filename " << filename_;
-    DLOG(INFO) << "Samples " << samples_;
-    DLOG(INFO) << "Sampling frequency " << sampling_frequency_;
-    DLOG(INFO) << "Item type " << item_type_;
-    DLOG(INFO) << "Item size " << item_size_;
-    DLOG(INFO) << "Repeat " << repeat_;
-    DLOG(INFO) << "Dump " << dump_;
-    DLOG(INFO) << "Dump filename " << dump_filename_;
-    if (in_streams_ > 0)
         {
             LOG(ERROR) << "A signal source does not have an input stream";
         }
-    if (out_streams_ > 1)
+    if (out_streams > 1)
         {
             LOG(ERROR) << "This implementation only supports one output stream";
         }
 }
-
-
-void FileSignalSource::connect(gr::top_block_sptr top_block)
-{
-    if (samples_ > 0)
-        {
-            if (enable_throttle_control_ == true)
-                {
-                    top_block->connect(file_source_, 0, throttle_, 0);
-                    DLOG(INFO) << "connected file source to throttle";
-                    top_block->connect(throttle_, 0, valve_, 0);
-                    DLOG(INFO) << "connected throttle to valve";
-                    if (dump_)
-                        {
-                            top_block->connect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "connected valve to file sink";
-                        }
-                }
-            else
-                {
-                    top_block->connect(file_source_, 0, valve_, 0);
-                    DLOG(INFO) << "connected file source to valve";
-                    if (dump_)
-                        {
-                            top_block->connect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "connected valve to file sink";
-                        }
-                }
-        }
-    else
-        {
-            if (enable_throttle_control_ == true)
-                {
-                    top_block->connect(file_source_, 0, throttle_, 0);
-                    DLOG(INFO) << "connected file source to throttle";
-                    if (dump_)
-                        {
-                            top_block->connect(file_source_, 0, sink_, 0);
-                            DLOG(INFO) << "connected file source to sink";
-                        }
-                }
-            else
-                {
-                    if (dump_)
-                        {
-                            top_block->connect(file_source_, 0, sink_, 0);
-                            DLOG(INFO) << "connected file source to sink";
-                        }
-                }
-        }
-}
-
-
-void FileSignalSource::disconnect(gr::top_block_sptr top_block)
-{
-    if (samples_ > 0)
-        {
-            if (enable_throttle_control_ == true)
-                {
-                    top_block->disconnect(file_source_, 0, throttle_, 0);
-                    DLOG(INFO) << "disconnected file source to throttle";
-                    top_block->disconnect(throttle_, 0, valve_, 0);
-                    DLOG(INFO) << "disconnected throttle to valve";
-                    if (dump_)
-                        {
-                            top_block->disconnect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected valve to file sink";
-                        }
-                }
-            else
-                {
-                    top_block->disconnect(file_source_, 0, valve_, 0);
-                    DLOG(INFO) << "disconnected file source to valve";
-                    if (dump_)
-                        {
-                            top_block->disconnect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected valve to file sink";
-                        }
-                }
-        }
-    else
-        {
-            if (enable_throttle_control_ == true)
-                {
-                    top_block->disconnect(file_source_, 0, throttle_, 0);
-                    DLOG(INFO) << "disconnected file source to throttle";
-                    if (dump_)
-                        {
-                            top_block->disconnect(file_source_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected file source to sink";
-                        }
-                }
-            else
-                {
-                    if (dump_)
-                        {
-                            top_block->disconnect(file_source_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected file source to sink";
-                        }
-                }
-        }
-}
-
-
-gr::basic_block_sptr FileSignalSource::get_left_block()
-{
-    LOG(WARNING) << "Left block of a signal source should not be retrieved";
-    return gr::blocks::file_source::sptr();
-}
-
-
-gr::basic_block_sptr FileSignalSource::get_right_block()
-{
-    if (samples_ > 0)
-        {
-            return valve_;
-        }
-    if (enable_throttle_control_ == true)
-        {
-            return throttle_;
-        }
-    return file_source_;
-}

src/algorithms/signal_source/adapters/file_signal_source.h

@@ -21,15 +21,7 @@
 #ifndef GNSS_SDR_FILE_SIGNAL_SOURCE_H
 #define GNSS_SDR_FILE_SIGNAL_SOURCE_H
 
-#include "concurrent_queue.h"
+#include "file_source_base.h"
-#include "gnss_block_interface.h"
-#include <gnuradio/blocks/file_sink.h>
-#include <gnuradio/blocks/file_source.h>
-#include <gnuradio/blocks/throttle.h>
-#include <gnuradio/hier_block2.h>
-#include <pmt/pmt.h>
-#include <cstdint>
-#include <string>
 
 /** \addtogroup Signal_Source Signal Source
  * Classes for Signal Source management.
@@ -45,84 +37,16 @@ class ConfigurationInterface;
  * \brief Class that reads signals samples from a file
  * and adapts it to a SignalSourceInterface
  */
-class FileSignalSource : public GNSSBlockInterface
+class FileSignalSource : public FileSourceBase
 {
 public:
-    FileSignalSource(const ConfigurationInterface* configuration, const std::string& role,
+    FileSignalSource(ConfigurationInterface const* configuration, std::string const& role,
         unsigned int in_streams, unsigned int out_streams,
         Concurrent_Queue<pmt::pmt_t>* queue);
 
     ~FileSignalSource() = default;
 
-    inline std::string role() override
-    {
-        return role_;
-    }
-
-    /*!
-     * \brief Returns "File_Signal_Source".
-     */
-    inline std::string implementation() override
-    {
-        return "File_Signal_Source";
-    }
-
-    inline size_t item_size() override
-    {
-        return item_size_;
-    }
-
-    void connect(gr::top_block_sptr top_block) override;
-    void disconnect(gr::top_block_sptr top_block) override;
-    gr::basic_block_sptr get_left_block() override;
-    gr::basic_block_sptr get_right_block() override;
-
-    inline std::string filename() const
-    {
-        return filename_;
-    }
-
-    inline std::string item_type() const
-    {
-        return item_type_;
-    }
-
-    inline bool repeat() const
-    {
-        return repeat_;
-    }
-
-    inline int64_t sampling_frequency() const
-    {
-        return sampling_frequency_;
-    }
-
-    inline uint64_t samples() const
-    {
-        return samples_;
-    }
-
 private:
-    gr::blocks::file_source::sptr file_source_;
-    gnss_shared_ptr<gr::block> valve_;
-    gr::blocks::file_sink::sptr sink_;
-    gr::blocks::throttle::sptr throttle_;
-
-    std::string role_;
-    std::string item_type_;
-    std::string filename_;
-    std::string dump_filename_;
-
-    uint64_t samples_;
-    int64_t sampling_frequency_;
-    size_t item_size_;
-
-    uint32_t in_streams_;
-    uint32_t out_streams_;
-
-    bool enable_throttle_control_;
-    bool repeat_;
-    bool dump_;
 };
 
 

src/algorithms/signal_source/adapters/file_source_base.cc

@@ -0,0 +1,506 @@
+/*!
+ * \file file_source_base.cc
+ * \brief Implementation of the base class for file-oriented signal_source GNSS blocks
+ * \author Jim Melton, 2021. jim.melton(at)sncorp.com
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
+ * This file is part of GNSS-SDR.
+ *
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * -----------------------------------------------------------------------------
+ */
+
+#include "file_source_base.h"
+#include "configuration_interface.h"
+#include "gnss_sdr_filesystem.h"
+#include "gnss_sdr_flags.h"
+#include "gnss_sdr_string_literals.h"
+#include "gnss_sdr_valve.h"
+#include <glog/logging.h>
+#include <cmath>  // ceil, floor
+#include <fstream>
+#include <utility>  // move
+
+
+using namespace std::string_literals;
+
+FileSourceBase::FileSourceBase(ConfigurationInterface const* configuration, std::string const& role, std::string impl,
+    Concurrent_Queue<pmt::pmt_t>* queue,
+    std::string default_item_type)
+    : SignalSourceBase(configuration, role, std::move(impl)), filename_(configuration->property(role + ".filename"s, "../data/example_capture.dat"s)),
+
+      file_source_(),  // NOLINT
+
+      item_type_(configuration->property(role + ".item_type"s, default_item_type)),  // NOLINT
+      item_size_(0),
+      is_complex_(false),
+
+      // apparently, MacOS (LLVM) finds 0UL ambiguous with bool, int64_t, uint64_t, int32_t, int16_t, uint16_t,... float, double
+      header_size_(configuration->property(role + ".header_size"s, uint64_t(0))),
+      seconds_to_skip_(configuration->property(role + ".seconds_to_skip"s, 0.0)),
+      repeat_(configuration->property(role + ".repeat"s, false)),
+
+      samples_(configuration->property(role + ".samples"s, uint64_t(0))),
+      sampling_frequency_(configuration->property(role + ".sampling_frequency"s, int64_t(0))),
+      valve_(),  // NOLINT
+      queue_(queue),
+
+      enable_throttle_control_(configuration->property(role + ".enable_throttle_control"s, false)),
+      throttle_(),  // NOLINT
+
+      dump_(configuration->property(role + ".dump"s, false)),
+      dump_filename_(configuration->property(role + ".dump_filename"s, "../data/my_capture.dat"s)),
+      sink_()  // NOLINT
+{
+    // override value with commandline flag, if present
+    if (FLAGS_signal_source != "-")
+        {
+            filename_ = FLAGS_signal_source;
+        }
+    if (FLAGS_s != "-")
+        {
+            filename_ = FLAGS_s;
+        }
+}
+
+
+void FileSourceBase::init()
+{
+    create_file_source();
+
+    // At this point, we know that the file exists
+    samples_ = computeSamplesInFile();
+    auto signal_duration_s = 1.0 * samples_ / sampling_frequency_;
+
+    if (is_complex())
+        {
+            signal_duration_s /= 2.0;
+        }
+
+    DLOG(INFO) << "Total number samples to be processed= " << samples_ << " GNSS signal duration= " << signal_duration_s << " [s]";
+    std::cout << "GNSS signal recorded time to be processed: " << signal_duration_s << " [s]\n";
+
+    DLOG(INFO) << "File source filename " << filename_;
+    DLOG(INFO) << "Samples " << samples_;
+    DLOG(INFO) << "Sampling frequency " << sampling_frequency_;
+    DLOG(INFO) << "Item type " << item_type_;
+    DLOG(INFO) << "Item size " << item_size_;
+    DLOG(INFO) << "Repeat " << repeat_;
+
+    DLOG(INFO) << "Dump " << dump_;
+    DLOG(INFO) << "Dump filename " << dump_filename_;
+
+    create_throttle();
+    create_valve();
+    create_sink();
+}
+
+
+void FileSourceBase::connect(gr::top_block_sptr top_block)
+{
+    init();
+    pre_connect_hook(top_block);
+
+    auto input = gr::basic_block_sptr();
+    auto output = gr::basic_block_sptr();
+
+    // THROTTLE
+    if (throttle())
+        {
+            // if we are throttling...
+            top_block->connect(source(), 0, throttle(), 0);
+            DLOG(INFO) << "connected file source to throttle";
+
+            input = throttle();
+        }
+    else
+        {
+            // no throttle; let 'er rip
+            input = source();
+        }
+
+    // VALVE
+    if (valve())
+        {
+            top_block->connect(input, 0, valve(), 0);
+            DLOG(INFO) << "connected source to valve";
+
+            output = valve();
+        }
+    else
+        {
+            // TODO: dumping a file source is unlikely, but should this be the raw file source or the
+            // throttle if there is one?  I'm leaning towards "output=input"
+            output = source();  // output = input;
+        }
+
+    // DUMP
+    if (sink())
+        {
+            top_block->connect(output, 0, sink(), 0);
+            DLOG(INFO) << "connected output to file sink";
+        }
+
+    post_connect_hook(top_block);
+}
+
+
+void FileSourceBase::disconnect(gr::top_block_sptr top_block)
+{
+    auto input = gr::basic_block_sptr();
+    auto output = gr::basic_block_sptr();
+
+    pre_disconnect_hook(top_block);
+
+    // THROTTLE
+    if (throttle())
+        {
+            // if we are throttling...
+            top_block->disconnect(source(), 0, throttle(), 0);
+            DLOG(INFO) << "disconnected file source from throttle";
+
+            input = throttle();
+        }
+    else
+        {
+            // no throttle; let 'er rip
+            input = source();
+        }
+
+    // VALVE
+    if (valve())
+        {
+            top_block->disconnect(input, 0, valve(), 0);
+            DLOG(INFO) << "disconnected source to valve";
+
+            output = valve();
+        }
+    else
+        {
+            // TODO: dumping a file source is unlikely, but should this be the raw file source or the
+            // throttle if there is one?  I'm leaning towards "output=input"
+            output = source();  // output = input;
+        }
+
+    // DUMP
+    if (sink())
+        {
+            top_block->disconnect(output, 0, sink(), 0);
+            DLOG(INFO) << "disconnected output to file sink";
+        }
+
+    post_disconnect_hook(top_block);
+}
+
+
+gr::basic_block_sptr FileSourceBase::get_left_block()
+{
+    // TODO: is this right? Shouldn't the left block be a nullptr?
+    LOG(WARNING) << "Left block of a signal source should not be retrieved";
+    return gr::blocks::file_source::sptr();
+}
+
+
+gr::basic_block_sptr FileSourceBase::get_right_block()
+{
+    // clang-tidy wants braces around the if-conditions. clang-format wants to break the braces into
+    // multiple line blocks. It's much more readable this way
+    // clang-format off
+    if (valve_) { return valve_; }
+    if (throttle_) { return throttle_; }
+    return source();
+    // clang-format on
+}
+
+
+std::string FileSourceBase::filename() const
+{
+    return filename_;
+}
+
+
+std::string FileSourceBase::item_type() const
+{
+    return item_type_;
+}
+
+
+size_t FileSourceBase::item_size()
+{
+    return item_size_;
+}
+
+
+size_t FileSourceBase::item_size() const
+{
+    return item_size_;
+}
+
+
+bool FileSourceBase::repeat() const
+{
+    return repeat_;
+}
+
+
+int64_t FileSourceBase::sampling_frequency() const
+{
+    return sampling_frequency_;
+}
+
+
+uint64_t FileSourceBase::samples() const
+{
+    return samples_;
+}
+
+
+std::tuple<size_t, bool> FileSourceBase::itemTypeToSize()
+{
+    auto is_complex_t = false;
+    auto item_size = size_t(0);
+
+    if (item_type_ == "gr_complex")
+        {
+            item_size = sizeof(gr_complex);
+        }
+    else if (item_type_ == "float")
+        {
+            item_size = sizeof(float);
+        }
+    else if (item_type_ == "short")
+        {
+            item_size = sizeof(int16_t);
+        }
+    else if (item_type_ == "ishort")
+        {
+            item_size = sizeof(int16_t);
+            is_complex_t = true;
+        }
+    else if (item_type_ == "byte")
+        {
+            item_size = sizeof(int8_t);
+        }
+    else if (item_type_ == "ibyte")
+        {
+            item_size = sizeof(int8_t);
+            is_complex_t = true;
+        }
+    else
+        {
+            LOG(WARNING) << item_type_
+                         << " unrecognized item type. Using gr_complex.";
+            item_size = sizeof(gr_complex);
+        }
+
+    return std::make_tuple(item_size, is_complex_t);
+}
+
+
+// Default case is one decoded packet per one read sample
+double FileSourceBase::packetsPerSample() const { return 1.0; }
+
+
+size_t FileSourceBase::samplesToSkip() const
+{
+    auto samples_to_skip = size_t(0);
+
+    if (seconds_to_skip_ > 0)
+        {
+            // sampling_frequency is in terms of actual samples (output packets). If this source is
+            // compressed, there may be multiple packets per file (read) sample. First compute the
+            // actual number of samples to skip (function of time and sample rate)
+            samples_to_skip = static_cast<size_t>(seconds_to_skip_ * sampling_frequency_);
+
+            // convert from sample to input items, scaling this value to input item space
+            // (rounding up)
+            samples_to_skip = std::ceil(samples_to_skip / packetsPerSample());
+
+            // complex inputs require two input items for one sample (arguably, packetsPerSample could be scaled by 0.5)
+            if (is_complex())
+                {
+                    samples_to_skip *= 2;
+                }
+        }
+
+    if (header_size_ > 0)
+        {
+            samples_to_skip += header_size_;
+        }
+
+    return samples_to_skip;
+}
+
+
+size_t FileSourceBase::computeSamplesInFile() const
+{
+    auto n_samples = size_t(samples());
+
+    // if configured with 0 samples (read the whole file), figure out how many samples are in the file, and go from there
+    if (n_samples == 0)
+        {
+            // this could throw, but the existence of the file has been proven before we get here.
+            auto size = fs::file_size(filename());
+
+            // if there is some kind of compression/encoding, figure out the uncompressed number of samples
+            n_samples = std::floor(packetsPerSample() * size / item_size());
+
+            auto to_skip = samplesToSkip();
+
+            /*!
+	     * BUG workaround: The GNU Radio file source does not stop the receiver after reaching the End of File.
+	     * A possible solution is to compute the file length in samples using file size, excluding at least
+	     * the last 2 milliseconds, and enable always the valve block
+	     */
+            auto tail = static_cast<size_t>(std::ceil(0.002 * sampling_frequency()));
+
+            DLOG(INFO) << "Total samples in the file= " << n_samples;
+            std::cout << "Processing file " << filename() << ", which contains " << n_samples << " samples (" << size << " bytes)\n";
+
+            if (n_samples > (to_skip + tail))
+                {
+                    // process all the samples available in the file excluding up to the last 2 ms
+                    n_samples -= to_skip + tail;
+                }
+            else
+                {
+                    // this will terminate the program
+                    LOG(FATAL) << "Skipping " << to_skip << " samples from the front and truncating 2ms (" << tail << " samples)\n"
+                               << "is greater than the number of samples in the file (" << n_samples << ")";
+                }
+        }
+
+    return n_samples;
+}
+
+
+size_t FileSourceBase::source_item_size() const
+{
+    // delegate the size of the source to the source() object, so sub-classes have less work to do
+    DLOG(INFO) << "source_item_size is " << source()->output_signature()->sizeof_stream_item(0);
+    return source()->output_signature()->sizeof_stream_item(0);
+}
+
+
+bool FileSourceBase::is_complex() const { return is_complex_; }
+
+
+// Simple accessors
+gnss_shared_ptr<gr::block> FileSourceBase::source() const { return file_source(); }
+gnss_shared_ptr<gr::block> FileSourceBase::file_source() const { return file_source_; }
+gnss_shared_ptr<gr::block> FileSourceBase::valve() const { return valve_; }
+gnss_shared_ptr<gr::block> FileSourceBase::throttle() const { return throttle_; }
+gnss_shared_ptr<gr::block> FileSourceBase::sink() const { return sink_; }
+
+
+gr::blocks::file_source::sptr FileSourceBase::create_file_source()
+{
+    auto item_tuple = itemTypeToSize();
+    item_size_ = std::get<0>(item_tuple);
+    is_complex_ = std::get<1>(item_tuple);
+
+    try
+        {
+            // TODO: why are we manually seeking, instead of passing the samples_to_skip to the file_source factory?
+            auto samples_to_skip = samplesToSkip();
+
+            file_source_ = gr::blocks::file_source::make(item_size(), filename().data(), repeat());
+
+            if (samples_to_skip > 0)
+                {
+                    LOG(INFO) << "Skipping " << samples_to_skip << " samples of the input file";
+                    if (not file_source_->seek(samples_to_skip, SEEK_SET))
+                        {
+                            LOG(ERROR) << "Error skipping bytes!";
+                        }
+                }
+        }
+    catch (const std::exception& e)
+        {
+            std::cerr
+                << "The receiver was configured to work with a file-based signal source\n"
+                << "but the specified file is unreachable by GNSS-SDR.\n"
+                << "[" << filename() << "]\n"
+                << "\n"
+                << "Please modify your configuration file\n"
+                << "and point SignalSource.filename to a valid raw data file. Then:\n"
+                << "$ gnss-sdr --config_file=/path/to/my_GNSS_SDR_configuration.conf\n"
+                << "Examples of configuration files available at:\n"
+                << GNSSSDR_INSTALL_DIR "/share/gnss-sdr/conf/\n"
+                << std::endl;
+
+            LOG(ERROR) << "file_signal_source: Unable to open the samples file "
+                       << filename() << ", exiting the program.";
+            throw;
+        }
+
+    DLOG(INFO) << implementation() << "(" << file_source_->unique_id() << ")";
+
+    // enable subclass hooks
+    create_file_source_hook();
+
+    return file_source_;
+}
+
+
+gr::blocks::throttle::sptr FileSourceBase::create_throttle()
+{
+    if (enable_throttle_control_)
+        {
+            // if we are throttling...
+            throttle_ = gr::blocks::throttle::make(source_item_size(), sampling_frequency());
+            DLOG(INFO) << "throttle(" << throttle_->unique_id() << ")";
+
+            // enable subclass hooks
+            create_throttle_hook();
+        }
+    return throttle_;
+}
+
+
+gnss_shared_ptr<gr::block> FileSourceBase::create_valve()
+{
+    if (samples() > 0)
+        {
+            // if a number of samples is specified, honor it by creating a valve
+            // In practice, this is always true
+            valve_ = gnss_sdr_make_valve(source_item_size(), samples(), queue_);
+            DLOG(INFO) << "valve(" << valve_->unique_id() << ")";
+
+            // enable subclass hooks
+            create_valve_hook();
+        }
+    return valve_;
+}
+
+
+gr::blocks::file_sink::sptr FileSourceBase::create_sink()
+{
+    if (dump_)
+        {
+            sink_ = gr::blocks::file_sink::make(source_item_size(), dump_filename_.c_str());
+            DLOG(INFO) << "file_sink(" << sink_->unique_id() << ")";
+
+            // enable subclass hooks
+            create_sink_hook();
+        }
+    return sink_;
+}
+
+
+// Subclass hooks to augment created objects, as required
+void FileSourceBase::create_file_source_hook() {}
+void FileSourceBase::create_throttle_hook() {}
+void FileSourceBase::create_valve_hook() {}
+void FileSourceBase::create_sink_hook() {}
+
+
+// Subclass hooks for connection/disconnectino
+void FileSourceBase::pre_connect_hook(gr::top_block_sptr top_block [[maybe_unused]]) {}
+void FileSourceBase::post_connect_hook(gr::top_block_sptr top_block [[maybe_unused]]) {}
+void FileSourceBase::pre_disconnect_hook(gr::top_block_sptr top_block [[maybe_unused]]) {}
+void FileSourceBase::post_disconnect_hook(gr::top_block_sptr top_block [[maybe_unused]]) {}

src/algorithms/signal_source/adapters/file_source_base.h

@@ -0,0 +1,186 @@
+/*!
+ * \file file_source_base.h
+ * \brief Header file of the base class to file-oriented signal_source GNSS blocks.
+ * \author Jim Melton, 2021. jim.melton(at)sncorp.com
+ *
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
+ * This file is part of GNSS-SDR.
+ *
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * -----------------------------------------------------------------------------
+ */
+
+#ifndef GNSS_SDR_FILE_SOURCE_BASE_H
+#define GNSS_SDR_FILE_SOURCE_BASE_H
+
+#include "concurrent_queue.h"
+#include "signal_source_base.h"
+#include <gnuradio/blocks/file_source.h>
+#include <gnuradio/blocks/throttle.h>
+#include <pmt/pmt.h>
+#include <tuple>
+
+// for dump
+#include <gnuradio/blocks/file_sink.h>
+#include <cstddef>
+#include <string>
+
+
+class ConfigurationInterface;
+
+
+//! \brief Base class to file-oriented SignalSourceBase GNSS blocks.
+//!
+//! This class supports the following properties:
+//!
+//!   .filename - the path to the input file
+//!             - may be overridden by the -signal_source or -s command-line arguments
+//!
+//!   .samples  - number of samples to process (default 0)
+//!             - if not specified or 0, read the entire file; otherwise stop after that many samples
+//!
+//!   .sampling_frequency - the frequency of the sampled data (samples/second)
+//!
+//!   .item_type - data type of the samples (default "short")
+//!
+//!   .header_size - the size of a prefixed header to skip in "samples" (default 0)
+//!
+//!   .seconds_to_skip - number of seconds of lead-in data to skip over (default 0)
+//!
+//!   .enable_throttle_control - whether to stop reading if the upstream buffer is full (default false)
+//!
+//!   .repeat   - whether to rewind and continue at end of file (default false)
+//!
+//! (probably abstracted to the base class)
+//!
+//!   .dump     - whether to archive input data
+//!
+//!   .dump_filename - if dumping, path to file for output
+
+
+class FileSourceBase : public SignalSourceBase
+{
+public:
+    // Virtual overrides
+    void connect(gr::top_block_sptr top_block) override;
+    void disconnect(gr::top_block_sptr top_block) override;
+    gr::basic_block_sptr get_left_block() override;
+    gr::basic_block_sptr get_right_block() override;
+
+    //! The file to read
+    std::string filename() const;
+
+    //! The item type
+    std::string item_type() const;
+
+    //! The configured size of each item
+    size_t item_size() override;
+    virtual size_t item_size() const;  // what the interface **should** have declared
+
+    //! Whether to repeat reading after end-of-file
+    bool repeat() const;
+
+    //! The sampling frequency of the source file
+    int64_t sampling_frequency() const;
+
+    //! The number of samples in the file
+    uint64_t samples() const;
+
+protected:
+    //! \brief Constructor
+    //!
+    //! Subclasses may want to assert default item types that are appropriate to the specific file
+    //! type supported. Rather than require the item type to be specified in the config file, allow
+    //! sub-classes to impose their will
+    FileSourceBase(ConfigurationInterface const* configuration, std::string const& role, std::string impl,
+        Concurrent_Queue<pmt::pmt_t>* queue,
+        std::string default_item_type = "short");
+
+    //! Perform post-construction initialization
+    void init();
+
+    //! Compute the item size, from the item_type(). Subclasses may constrain types that don't make
+    //  sense. The return of this method is a tuple of item_size and is_complex
+    virtual std::tuple<size_t, bool> itemTypeToSize();
+
+    //! The number of (possibly unpacked) samples in a (raw) file sample (default=1)
+    virtual double packetsPerSample() const;
+
+    //! Compute the number of samples to skip
+    virtual size_t samplesToSkip() const;
+
+    //! Compute the number of samples in the file
+    size_t computeSamplesInFile() const;
+
+    //! Abstracted front-end source. Sub-classes may override if they create specialized chains to
+    //! decode source files into a usable format
+    virtual gnss_shared_ptr<gr::block> source() const;
+
+    //! For complex source chains, the size of the file item may not be the same as the size of the
+    // "source" (decoded) item. This method allows subclasses to handle these differences
+    virtual size_t source_item_size() const;
+    bool is_complex() const;
+
+    // Generic access to created objects
+    gnss_shared_ptr<gr::block> file_source() const;
+    gnss_shared_ptr<gr::block> valve() const;
+    gnss_shared_ptr<gr::block> throttle() const;
+    gnss_shared_ptr<gr::block> sink() const;
+
+    // The methods create the various blocks, if enabled, and return access to them. The created
+    // object is also held in this class
+    gr::blocks::file_source::sptr create_file_source();
+    gr::blocks::throttle::sptr create_throttle();
+    gnss_shared_ptr<gr::block> create_valve();
+    gr::blocks::file_sink::sptr create_sink();
+
+    // Subclass hooks to augment created objects, as required
+    virtual void create_file_source_hook();
+    virtual void create_throttle_hook();
+    virtual void create_valve_hook();
+    virtual void create_sink_hook();
+
+    // Subclass hooks for connection/disconnection
+    virtual void pre_connect_hook(gr::top_block_sptr top_block);
+    virtual void post_connect_hook(gr::top_block_sptr top_block);
+    virtual void pre_disconnect_hook(gr::top_block_sptr top_block);
+    virtual void post_disconnect_hook(gr::top_block_sptr top_block);
+
+private:
+    std::string filename_;
+    gr::blocks::file_source::sptr file_source_;
+
+    std::string item_type_;
+    size_t item_size_;
+    bool is_complex_;  // a misnomer; if I/Q are interleaved as integer values
+
+    size_t header_size_;  // length (in samples) of the header (if any)
+    double seconds_to_skip_;
+    bool repeat_;
+
+    // The valve allows only the configured number of samples through, then it closes.
+
+    // The framework passes the queue as a naked pointer, rather than a shared pointer, so this
+    // class has two choices: construct the valve in the ctor, or hold onto the pointer, possibly
+    // beyond its lifetime. Fortunately, the queue is only used to create the valve, so the
+    // likelihood of holding a stale pointer is mitigated
+    uint64_t samples_;
+    int64_t sampling_frequency_;  // why is this signed
+    gnss_shared_ptr<gr::block> valve_;
+    Concurrent_Queue<pmt::pmt_t>* queue_;
+
+    bool enable_throttle_control_;
+    gr::blocks::throttle::sptr throttle_;
+
+    bool dump_;
+    std::string dump_filename_;
+    gr::blocks::file_sink::sptr sink_;
+};
+
+
+#endif

src/algorithms/signal_source/adapters/flexiband_signal_source.cc

@@ -18,17 +18,21 @@
 
 #include "flexiband_signal_source.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 #include <gnuradio/blocks/file_sink.h>
 #include <teleorbit/frontend.h>
 #include <utility>
 
+using namespace std::string_literals;
+
 
 FlexibandSignalSource::FlexibandSignalSource(const ConfigurationInterface* configuration,
     const std::string& role,
     unsigned int in_stream,
     unsigned int out_stream,
-    Concurrent_Queue<pmt::pmt_t>* queue __attribute__((unused))) : role_(role), in_stream_(in_stream), out_stream_(out_stream)
+    Concurrent_Queue<pmt::pmt_t>* queue __attribute__((unused)))
+    : SignalSourceBase(configuration, role, "Flexiband_Signal_Source"s), in_stream_(in_stream), out_stream_(out_stream)
 {
     const std::string default_item_type("byte");
     item_type_ = configuration->property(role + ".item_type", default_item_type);

src/algorithms/signal_source/adapters/flexiband_signal_source.h

@@ -21,7 +21,7 @@
 #define GNSS_SDR_FLEXIBAND_SIGNAL_SOURCE_H
 
 #include "concurrent_queue.h"
-#include "gnss_block_interface.h"
+#include "signal_source_base.h"
 #include <gnuradio/blocks/char_to_float.h>
 #include <gnuradio/blocks/file_sink.h>
 #include <gnuradio/blocks/float_to_complex.h>
@@ -45,7 +45,7 @@ class ConfigurationInterface;
  * \brief This class configures and reads samples from Teleorbit Flexiband front-end.
  * This software requires a Flexiband GNU Radio driver installed (not included with GNSS-SDR).
  */
-class FlexibandSignalSource : public GNSSBlockInterface
+class FlexibandSignalSource : public SignalSourceBase
 {
 public:
     FlexibandSignalSource(const ConfigurationInterface* configuration,
@@ -54,19 +54,6 @@ public:
 
     ~FlexibandSignalSource() = default;
 
-    inline std::string role() override
-    {
-        return role_;
-    }
-
-    /*!
-     * \brief Returns "Flexiband_Signal_Source".
-     */
-    inline std::string implementation() override
-    {
-        return "Flexiband_Signal_Source";
-    }
-
     inline size_t item_size() override
     {
         return item_size_;
@@ -85,7 +72,6 @@ private:
     std::vector<boost::shared_ptr<gr::block>> float_to_complex_;
     std::vector<gr::blocks::null_sink::sptr> null_sinks_;
 
-    std::string role_;
     std::string item_type_;
     std::string firmware_filename_;
     std::string signal_file;

src/algorithms/signal_source/adapters/fmcomms2_signal_source.cc

@@ -22,6 +22,7 @@
 #include "ad9361_manager.h"
 #include "configuration_interface.h"
 #include "gnss_sdr_flags.h"
+#include "gnss_sdr_string_literals.h"
 #include "gnss_sdr_valve.h"
 #include <glog/logging.h>
 #include <algorithm>  // for max
@@ -29,10 +30,12 @@
 #include <iostream>
 #include <utility>
 
+using namespace std::string_literals;
 
 Fmcomms2SignalSource::Fmcomms2SignalSource(const ConfigurationInterface *configuration,
     const std::string &role, unsigned int in_stream, unsigned int out_stream,
-    Concurrent_Queue<pmt::pmt_t> *queue) : role_(role), in_stream_(in_stream), out_stream_(out_stream)
+    Concurrent_Queue<pmt::pmt_t> *queue)
+    : SignalSourceBase(configuration, role, "Fmcomms2_Signal_Source"s), in_stream_(in_stream), out_stream_(out_stream)
 {
     const std::string default_item_type("gr_complex");
     const std::string default_dump_file("./data/signal_source.dat");

src/algorithms/signal_source/adapters/fmcomms2_signal_source.h

@@ -20,7 +20,7 @@
 #ifndef GNSS_SDR_FMCOMMS2_SIGNAL_SOURCE_H
 #define GNSS_SDR_FMCOMMS2_SIGNAL_SOURCE_H
 
-#include "gnss_block_interface.h"
+#include "signal_source_base.h"
 #include <gnuradio/blocks/file_sink.h>
 #if GRIIO_INCLUDE_HAS_GNURADIO
 #include <gnuradio/iio/fmcomms2_source.h>
@@ -41,7 +41,7 @@
 
 class ConfigurationInterface;
 
-class Fmcomms2SignalSource : public GNSSBlockInterface
+class Fmcomms2SignalSource : public SignalSourceBase
 {
 public:
     Fmcomms2SignalSource(const ConfigurationInterface* configuration,
@@ -50,19 +50,6 @@ public:
 
     ~Fmcomms2SignalSource();
 
-    inline std::string role() override
-    {
-        return role_;
-    }
-
-    /*!
-     * \brief Returns "Fmcomms2_Signal_Source"
-     */
-    inline std::string implementation() override
-    {
-        return "Fmcomms2_Signal_Source";
-    }
-
     inline size_t item_size() override
     {
         return item_size_;
@@ -78,7 +65,6 @@ private:
     gnss_shared_ptr<gr::block> valve_;
     gr::blocks::file_sink::sptr file_sink_;
 
-    std::string role_;
     std::string item_type_;
     std::string dump_filename_;
 

src/algorithms/signal_source/adapters/gen_signal_source.h

@@ -22,6 +22,7 @@
 
 #include "concurrent_queue.h"
 #include "gnss_block_interface.h"
+#include "signal_source_interface.h"
 #include <pmt/pmt.h>
 #include <memory>
 #include <string>
@@ -37,16 +38,13 @@
  * \brief This class wraps blocks that generates synthesized GNSS signal and
  * filters the signal.
  */
-class GenSignalSource : public GNSSBlockInterface
+class GenSignalSource : public SignalSourceInterface
 {
 public:
     //! Constructor
     GenSignalSource(std::shared_ptr<GNSSBlockInterface> signal_generator, std::shared_ptr<GNSSBlockInterface> filter,
         std::string role, Concurrent_Queue<pmt::pmt_t> *queue);
 
-    //! Virtual destructor
-    virtual ~GenSignalSource() = default;
-
     void connect(gr::top_block_sptr top_block) override;
     void disconnect(gr::top_block_sptr top_block) override;
     gr::basic_block_sptr get_left_block() override;
@@ -56,6 +54,8 @@ public:
     //! Returns "Signal Source"
     inline std::string implementation() override { return "Signal Source"; }
     inline size_t item_size() override { return 0; }
+    inline size_t getRfChannels() const final { return 0; }
+
     inline std::shared_ptr<GNSSBlockInterface> signal_generator() const { return signal_generator_; }
 
 private:

src/algorithms/signal_source/adapters/gn3s_signal_source.cc

@@ -16,16 +16,20 @@
 
 #include "gn3s_signal_source.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 #include <gnuradio/blocks/file_sink.h>
 #include <gn3s/gn3s_source_cc.h>
 
+using namespace std::string_literals;
+
 
 Gn3sSignalSource::Gn3sSignalSource(const ConfigurationInterface* configuration,
     std::string role,
     unsigned int in_stream,
     unsigned int out_stream,
-    Concurrent_Queue<pmt::pmt_t>* queue) : role_(role), in_stream_(in_stream), out_stream_(out_stream)
+    Concurrent_Queue<pmt::pmt_t>* queue)
+    : SignalSourceBase(configuration, role, "Gn3s_Signal_Source"s), in_stream_(in_stream), out_stream_(out_stream)
 {
     const std::string default_item_type("short");
     const std::string default_dump_file("./data/gn3s_source.dat");

src/algorithms/signal_source/adapters/gn3s_signal_source.h

@@ -19,7 +19,7 @@
 #define GNSS_SDR_GN3S_SIGNAL_SOURCE_H
 
 #include "concurrent_queue.h"
-#include "gnss_block_interface.h"
+#include "signal_source_base.h"
 #include <gnuradio/blocks/file_sink.h>
 #include <gnuradio/hier_block2.h>
 #include <pmt/pmt.h>
@@ -38,7 +38,7 @@ class ConfigurationInterface;
 /*!
  * \brief This class reads samples from a GN3S USB dongle, a RF front-end signal sampler
  */
-class Gn3sSignalSource : public GNSSBlockInterface
+class Gn3sSignalSource : public SignalSourceBase
 {
 public:
     Gn3sSignalSource(const ConfigurationInterface* configuration,
@@ -47,19 +47,6 @@ public:
 
     ~Gn3sSignalSource() = default;
 
-    inline std::string role() override
-    {
-        return role_;
-    }
-
-    /*!
-     * \brief Returns "Gn3s_Signal_Source".
-     */
-    inline std::string implementation() override
-    {
-        return "Gn3s_Signal_Source";
-    }
-
     inline size_t item_size() override
     {
         return item_size_;
@@ -73,11 +60,10 @@ public:
 private:
     gr::block_sptr gn3s_source_;
     gr::blocks::file_sink::sptr file_sink_;
-    std::string role_;
     std::string item_type_;
     std::string dump_filename_;
     size_t item_size_;
-    int64_t samples_;
+    [[maybe_unused]] int64_t samples_;
     unsigned int in_stream_;
     unsigned int out_stream_;
     bool dump_;

src/algorithms/signal_source/adapters/labsat_signal_source.cc

@@ -16,14 +16,15 @@
 
 #include "labsat_signal_source.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include "labsat23_source.h"
 #include <glog/logging.h>
-#include <cstdint>
-#include <utility>
 
+using namespace std::string_literals;
 
 LabsatSignalSource::LabsatSignalSource(const ConfigurationInterface* configuration,
-    const std::string& role, unsigned int in_stream, unsigned int out_stream, Concurrent_Queue<pmt::pmt_t>* queue) : role_(role), in_stream_(in_stream), out_stream_(out_stream)
+    const std::string& role, unsigned int in_stream, unsigned int out_stream, Concurrent_Queue<pmt::pmt_t>* queue)
+    : SignalSourceBase(configuration, role, "Labsat_Signal_Source"s), in_stream_(in_stream), out_stream_(out_stream)
 {
     const std::string default_item_type("gr_complex");
     const std::string default_dump_file("./labsat_output.dat");

src/algorithms/signal_source/adapters/labsat_signal_source.h

@@ -20,6 +20,7 @@
 
 #include "concurrent_queue.h"
 #include "gnss_block_interface.h"
+#include "signal_source_base.h"
 #include <gnuradio/blocks/file_sink.h>
 #include <gnuradio/blocks/throttle.h>
 #include <gnuradio/hier_block2.h>
@@ -38,7 +39,7 @@ class ConfigurationInterface;
 /*!
  * \brief This class reads samples stored by a LabSat 2 or LabSat 3 device
  */
-class LabsatSignalSource : public GNSSBlockInterface
+class LabsatSignalSource : public SignalSourceBase
 {
 public:
     LabsatSignalSource(const ConfigurationInterface* configuration,
@@ -47,19 +48,6 @@ public:
 
     ~LabsatSignalSource() = default;
 
-    inline std::string role() override
-    {
-        return role_;
-    }
-
-    /*!
-     * \brief Returns "Labsat_Signal_Source".
-     */
-    inline std::string implementation() override
-    {
-        return "Labsat_Signal_Source";
-    }
-
     inline size_t item_size() override
     {
         return item_size_;
@@ -75,7 +63,6 @@ private:
     gr::blocks::file_sink::sptr file_sink_;
     gr::blocks::throttle::sptr throttle_;
 
-    std::string role_;
     std::string item_type_;
     std::string filename_;
     std::string dump_filename_;

src/algorithms/signal_source/adapters/multichannel_file_signal_source.cc

@@ -18,6 +18,7 @@
 #include "multichannel_file_signal_source.h"
 #include "configuration_interface.h"
 #include "gnss_sdr_flags.h"
+#include "gnss_sdr_string_literals.h"
 #include "gnss_sdr_valve.h"
 #include <glog/logging.h>
 #include <exception>
@@ -27,18 +28,21 @@
 #include <utility>
 
 
+using namespace std::string_literals;
+
 MultichannelFileSignalSource::MultichannelFileSignalSource(const ConfigurationInterface* configuration,
     const std::string& role, unsigned int in_streams, unsigned int out_streams,
-    Concurrent_Queue<pmt::pmt_t>* queue) : role_(role), in_streams_(in_streams), out_streams_(out_streams)
+    Concurrent_Queue<pmt::pmt_t>* queue)
+    : SignalSourceBase(configuration, role, "Multichannel_File_Signal_Source"s), in_streams_(in_streams), out_streams_(out_streams)
 {
-    const std::string default_filename("./example_capture.dat");
+    const std::string default_filename("./example_capture.dat"s);
-    const std::string default_item_type("short");
+    const std::string default_item_type("short"s);
-    const std::string default_dump_filename("./my_capture.dat");
+    const std::string default_dump_filename("./my_capture.dat"s);
 
     const double default_seconds_to_skip = 0.0;
-    samples_ = configuration->property(role + ".samples", static_cast<uint64_t>(0));
+    samples_ = configuration->property(role + ".samples"s, static_cast<uint64_t>(0));
-    sampling_frequency_ = configuration->property(role + ".sampling_frequency", static_cast<int64_t>(0));
+    sampling_frequency_ = configuration->property(role + ".sampling_frequency"s, static_cast<int64_t>(0));
-    n_channels_ = configuration->property(role + ".total_channels", 1);
+    n_channels_ = configuration->property(role + ".total_channels"s, 1);
 
     for (int32_t n = 0; n < n_channels_; n++)
         {

src/algorithms/signal_source/adapters/multichannel_file_signal_source.h

@@ -23,6 +23,7 @@
 
 #include "concurrent_queue.h"
 #include "gnss_block_interface.h"
+#include "signal_source_base.h"
 #include <gnuradio/blocks/file_sink.h>
 #include <gnuradio/blocks/file_source.h>
 #include <gnuradio/blocks/throttle.h>
@@ -45,7 +46,7 @@ class ConfigurationInterface;
  * \brief Class that reads signals samples from files at different frequency bands
  * and adapts it to a SignalSourceInterface
  */
-class MultichannelFileSignalSource : public GNSSBlockInterface
+class MultichannelFileSignalSource : public SignalSourceBase
 {
 public:
     MultichannelFileSignalSource(const ConfigurationInterface* configuration, const std::string& role,
@@ -54,19 +55,6 @@ public:
 
     ~MultichannelFileSignalSource() = default;
 
-    inline std::string role() override
-    {
-        return role_;
-    }
-
-    /*!
-     * \brief Returns "Multichannel_File_Signal_Source".
-     */
-    inline std::string implementation() override
-    {
-        return "Multichannel_File_Signal_Source";
-    }
-
     inline size_t item_size() override
     {
         return item_size_;
@@ -109,7 +97,6 @@ private:
     std::vector<gr::blocks::throttle::sptr> throttle_vec_;
     std::vector<std::string> filename_vec_;
     std::string item_type_;
-    std::string role_;
     uint64_t samples_;
     int64_t sampling_frequency_;
     size_t item_size_;

src/algorithms/signal_source/adapters/nsr_file_signal_source.cc

@@ -10,286 +10,69 @@
  * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
  * This file is part of GNSS-SDR.
  *
- * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
  * -----------------------------------------------------------------------------
  */
 
 #include "nsr_file_signal_source.h"
-#include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
-#include "gnss_sdr_flags.h"
-#include "gnss_sdr_valve.h"
 #include <glog/logging.h>
-#include <exception>
-#include <fstream>
-#include <iomanip>
-#include <iostream>
-#include <utility>
 
+using namespace std::string_literals;
 
 NsrFileSignalSource::NsrFileSignalSource(const ConfigurationInterface* configuration,
     const std::string& role, unsigned int in_streams, unsigned int out_streams,
-    Concurrent_Queue<pmt::pmt_t>* queue) : role_(role), in_streams_(in_streams), out_streams_(out_streams)
+    Concurrent_Queue<pmt::pmt_t>* queue)
+    : FileSourceBase(configuration, role, "Nsr_File_Signal_Source"s, queue, "byte"s)
 {
-    const std::string default_filename("../data/my_capture.dat");
+    if (in_streams > 0)
-    const std::string default_item_type("byte");
-    const std::string default_dump_filename("../data/my_capture_dump.dat");
-
-    samples_ = configuration->property(role + ".samples", static_cast<uint64_t>(0));
-    sampling_frequency_ = configuration->property(role + ".sampling_frequency", static_cast<int64_t>(0));
-    filename_ = configuration->property(role + ".filename", default_filename);
-
-    // override value with commandline flag, if present
-    if (FLAGS_signal_source != "-")
-        {
-            filename_ = FLAGS_signal_source;
-        }
-    if (FLAGS_s != "-")
-        {
-            filename_ = FLAGS_s;
-        }
-
-    item_type_ = configuration->property(role + ".item_type", default_item_type);
-    repeat_ = configuration->property(role + ".repeat", false);
-    dump_ = configuration->property(role + ".dump", false);
-    dump_filename_ = configuration->property(role + ".dump_filename", default_dump_filename);
-    enable_throttle_control_ = configuration->property(role + ".enable_throttle_control", false);
-
-    if (item_type_ == "byte")
-        {
-            item_size_ = sizeof(char);
-        }
-    else
-        {
-            LOG(WARNING) << item_type_ << " unrecognized item type. Using byte.";
-            item_size_ = sizeof(char);
-        }
-    try
-        {
-            file_source_ = gr::blocks::file_source::make(item_size_, filename_.c_str(), repeat_);
-            unpack_byte_ = make_unpack_byte_2bit_samples();
-        }
-    catch (const std::exception& e)
-        {
-            std::cerr
-                << "The receiver was configured to work with a file signal source\n"
-                << "but the specified file is unreachable by GNSS-SDR.\n"
-                << "Please modify your configuration file\n"
-                << "and point SignalSource.filename to a valid raw data file. Then:\n"
-                << "$ gnss-sdr --config_file=/path/to/my_GNSS_SDR_configuration.conf\n"
-                << "Examples of configuration files available at:\n"
-                << GNSSSDR_INSTALL_DIR "/share/gnss-sdr/conf/\n";
-
-            LOG(WARNING) << "file_signal_source: Unable to open the samples file "
-                         << filename_.c_str() << ", exiting the program.";
-            throw(e);
-        }
-
-    DLOG(INFO) << "file_source(" << file_source_->unique_id() << ")";
-
-    if (samples_ == 0)  // read all file
-        {
-            /*!
-             * BUG workaround: The GNU Radio file source does not stop the receiver after reaching the End of File.
-             * A possible solution is to compute the file length in samples using file size, excluding the last 2 milliseconds, and enable always the
-             * valve block
-             */
-            std::ifstream file(filename_.c_str(), std::ios::in | std::ios::binary | std::ios::ate);
-            std::ifstream::pos_type size;
-
-            if (file.is_open())
-                {
-                    size = file.tellg();
-                    LOG(INFO) << "Total samples in the file= " << floor(static_cast<double>(size) / static_cast<double>(item_size()));
-                }
-            else
-                {
-                    std::cout << "file_signal_source: Unable to open the samples file " << filename_.c_str() << '\n';
-                    LOG(ERROR) << "file_signal_source: Unable to open the samples file " << filename_.c_str();
-                }
-            std::streamsize ss = std::cout.precision();
-            std::cout << std::setprecision(16);
-            std::cout << "Processing file " << filename_ << ", which contains " << size << " [bytes]\n";
-            std::cout.precision(ss);
-
-            if (size > 0)
-                {
-                    int sample_packet_factor = 4;  // 1 byte -> 4 samples
-                    samples_ = floor(static_cast<double>(size) / static_cast<double>(item_size())) * sample_packet_factor;
-                    samples_ = samples_ - ceil(0.002 * static_cast<double>(sampling_frequency_));  // process all the samples available in the file excluding the last 2 ms
-                }
-        }
-
-    CHECK(samples_ > 0) << "File does not contain enough samples to process.";
-    const double signal_duration_s = static_cast<double>(samples_) * (1 / static_cast<double>(sampling_frequency_));
-    LOG(INFO) << "Total number samples to be processed= " << samples_ << " GNSS signal duration= " << signal_duration_s << " [s]";
-    std::cout << "GNSS signal recorded time to be processed: " << signal_duration_s << " [s]\n";
-
-    valve_ = gnss_sdr_make_valve(sizeof(float), samples_, queue);
-    DLOG(INFO) << "valve(" << valve_->unique_id() << ")";
-
-    if (dump_)
-        {
-            // sink_ = gr_make_file_sink(item_size_, dump_filename_.c_str());
-            sink_ = gr::blocks::file_sink::make(sizeof(float), dump_filename_.c_str());
-            DLOG(INFO) << "file_sink(" << sink_->unique_id() << ")";
-        }
-
-    if (enable_throttle_control_)
-        {
-            throttle_ = gr::blocks::throttle::make(sizeof(float), sampling_frequency_);
-        }
-    DLOG(INFO) << "File source filename " << filename_;
-    DLOG(INFO) << "Samples " << samples_;
-    DLOG(INFO) << "Sampling frequency " << sampling_frequency_;
-    DLOG(INFO) << "Item type " << item_type_;
-    DLOG(INFO) << "Item size " << item_size_;
-    DLOG(INFO) << "Repeat " << repeat_;
-    DLOG(INFO) << "Dump " << dump_;
-    DLOG(INFO) << "Dump filename " << dump_filename_;
-    if (in_streams_ > 0)
         {
             LOG(ERROR) << "A signal source does not have an input stream";
         }
-    if (out_streams_ > 1)
+    if (out_streams > 1)
         {
             LOG(ERROR) << "This implementation only supports one output stream";
         }
 }
 
-
+std::tuple<size_t, bool> NsrFileSignalSource::itemTypeToSize()
-void NsrFileSignalSource::connect(gr::top_block_sptr top_block)
 {
-    if (samples_ > 0)
+    auto is_complex = false;
+    auto item_size = size_t(sizeof(char));  // default
+
+    if (item_type() == "byte")
         {
-            if (enable_throttle_control_ == true)
+            item_size = sizeof(char);
-                {
-                    top_block->connect(file_source_, 0, unpack_byte_, 0);
-                    top_block->connect(unpack_byte_, 0, throttle_, 0);
-                    DLOG(INFO) << "connected file source to throttle";
-                    top_block->connect(throttle_, 0, valve_, 0);
-                    DLOG(INFO) << "connected throttle to valve";
-                    if (dump_)
-                        {
-                            top_block->connect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "connected valve to file sink";
-                        }
-                }
-            else
-                {
-                    top_block->connect(file_source_, 0, unpack_byte_, 0);
-                    top_block->connect(unpack_byte_, 0, valve_, 0);
-                    DLOG(INFO) << "connected file source to valve";
-                    if (dump_)
-                        {
-                            top_block->connect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "connected valve to file sink";
-                        }
-                }
         }
     else
         {
-            if (enable_throttle_control_ == true)
+            LOG(WARNING) << item_type() << " unrecognized item type. Using byte.";
-                {
-                    top_block->connect(file_source_, 0, unpack_byte_, 0);
-                    top_block->connect(unpack_byte_, 0, throttle_, 0);
-                    DLOG(INFO) << "connected file source to throttle";
-                    if (dump_)
-                        {
-                            top_block->connect(throttle_, 0, sink_, 0);
-                            DLOG(INFO) << "connected file source to sink";
-                        }
-                }
-            else
-                {
-                    if (dump_)
-                        {
-                            top_block->connect(file_source_, 0, unpack_byte_, 0);
-                            top_block->connect(unpack_byte_, 0, sink_, 0);
-                            DLOG(INFO) << "connected file source to sink";
-                        }
-                }
         }
+
+    return std::make_tuple(item_size, is_complex);
 }
 
+// 1 byte -> 4 samples
+double NsrFileSignalSource::packetsPerSample() const { return 4.0; }
+gnss_shared_ptr<gr::block> NsrFileSignalSource::source() const { return unpack_byte_; }
 
-void NsrFileSignalSource::disconnect(gr::top_block_sptr top_block)
+
+void NsrFileSignalSource::create_file_source_hook()
 {
-    if (samples_ > 0)
+    unpack_byte_ = make_unpack_byte_2bit_samples();
-        {
+    DLOG(INFO) << "unpack_byte_2bit_samples(" << unpack_byte_->unique_id() << ")";
-            if (enable_throttle_control_ == true)
-                {
-                    top_block->disconnect(file_source_, 0, unpack_byte_, 0);
-                    DLOG(INFO) << "disconnected file source to unpack_byte_";
-                    top_block->connect(unpack_byte_, 0, throttle_, 0);
-                    DLOG(INFO) << "disconnected unpack_byte_ to throttle_";
-                    top_block->disconnect(throttle_, 0, valve_, 0);
-                    DLOG(INFO) << "disconnected throttle to valve";
-                    if (dump_)
-                        {
-                            top_block->disconnect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected valve to file sink";
-                        }
-                }
-            else
-                {
-                    top_block->disconnect(file_source_, 0, unpack_byte_, 0);
-                    DLOG(INFO) << "disconnected file source to unpack_byte_";
-                    top_block->disconnect(unpack_byte_, 0, valve_, 0);
-                    DLOG(INFO) << "disconnected unpack_byte_ to valve";
-                    if (dump_)
-                        {
-                            top_block->disconnect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected valve to file sink";
-                        }
-                }
-        }
-    else
-        {
-            if (enable_throttle_control_ == true)
-                {
-                    top_block->disconnect(file_source_, 0, unpack_byte_, 0);
-                    DLOG(INFO) << "disconnected file source to unpack_byte_";
-                    top_block->disconnect(unpack_byte_, 0, throttle_, 0);
-                    DLOG(INFO) << "disconnected unpack_byte_ to throttle";
-                    if (dump_)
-                        {
-                            top_block->disconnect(unpack_byte_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected funpack_byte_ to sink";
-                        }
-                }
-            else
-                {
-                    if (dump_)
-                        {
-                            top_block->disconnect(file_source_, 0, unpack_byte_, 0);
-                            DLOG(INFO) << "disconnected file source to unpack_byte_";
-                            top_block->disconnect(unpack_byte_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected unpack_byte_ to sink";
-                        }
-                }
-        }
 }
 
-
+void NsrFileSignalSource::pre_connect_hook(gr::top_block_sptr top_block)
-gr::basic_block_sptr NsrFileSignalSource::get_left_block()
 {
-    LOG(WARNING) << "Left block of a signal source should not be retrieved";
+    top_block->connect(file_source(), 0, unpack_byte_, 0);
-    // return gr_block_sptr();
+    DLOG(INFO) << "connected file_source to unpacker";
-    return gr::blocks::file_source::sptr();
 }
 
-
+void NsrFileSignalSource::pre_disconnect_hook(gr::top_block_sptr top_block)
-gr::basic_block_sptr NsrFileSignalSource::get_right_block()
 {
-    if (samples_ > 0)
+    top_block->disconnect(file_source(), 0, unpack_byte_, 0);
-        {
+    DLOG(INFO) << "disconnected file_source from unpacker";
-            return valve_;
-        }
-    if (enable_throttle_control_ == true)
-        {
-            return throttle_;
-        }
-    return unpack_byte_;
 }

src/algorithms/signal_source/adapters/nsr_file_signal_source.h

@@ -12,7 +12,7 @@
  * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
  * This file is part of GNSS-SDR.
  *
- * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
  * -----------------------------------------------------------------------------
@@ -21,15 +21,8 @@
 #ifndef GNSS_SDR_NSR_FILE_SIGNAL_SOURCE_H
 #define GNSS_SDR_NSR_FILE_SIGNAL_SOURCE_H
 
-#include "concurrent_queue.h"
+#include "file_source_base.h"
-#include "gnss_block_interface.h"
 #include "unpack_byte_2bit_samples.h"
-#include <gnuradio/blocks/file_sink.h>
-#include <gnuradio/blocks/file_source.h>
-#include <gnuradio/blocks/throttle.h>
-#include <gnuradio/hier_block2.h>
-#include <pmt/pmt.h>
-#include <string>
 
 /** \addtogroup Signal_Source
  * \{ */
@@ -42,7 +35,7 @@ class ConfigurationInterface;
  * \brief Class that reads signals samples from a file
  * and adapts it to a SignalSourceInterface
  */
-class NsrFileSignalSource : public GNSSBlockInterface
+class NsrFileSignalSource : public FileSourceBase
 {
 public:
     NsrFileSignalSource(const ConfigurationInterface* configuration, const std::string& role,
@@ -50,73 +43,17 @@ public:
         Concurrent_Queue<pmt::pmt_t>* queue);
 
     ~NsrFileSignalSource() = default;
-    inline std::string role() override
-    {
-        return role_;
-    }
 
-    /*!
+protected:
-     * \brief Returns "Nsr_File_Signal_Source".
+    std::tuple<size_t, bool> itemTypeToSize() override;
-     */
+    double packetsPerSample() const override;
-    inline std::string implementation() override
+    gnss_shared_ptr<gr::block> source() const override;
-    {
+    void create_file_source_hook() override;
-        return "Nsr_File_Signal_Source";
+    void pre_connect_hook(gr::top_block_sptr top_block) override;
-    }
+    void pre_disconnect_hook(gr::top_block_sptr top_block) override;
-
-    inline size_t item_size() override
-    {
-        return item_size_;
-    }
-
-    void connect(gr::top_block_sptr top_block) override;
-    void disconnect(gr::top_block_sptr top_block) override;
-    gr::basic_block_sptr get_left_block() override;
-    gr::basic_block_sptr get_right_block() override;
-
-    inline std::string filename() const
-    {
-        return filename_;
-    }
-
-    inline std::string item_type() const
-    {
-        return item_type_;
-    }
-
-    inline bool repeat() const
-    {
-        return repeat_;
-    }
-
-    inline int64_t sampling_frequency() const
-    {
-        return sampling_frequency_;
-    }
-
-    inline uint64_t samples() const
-    {
-        return samples_;
-    }
 
 private:
-    gr::blocks::file_source::sptr file_source_;
     unpack_byte_2bit_samples_sptr unpack_byte_;
-    gnss_shared_ptr<gr::block> valve_;
-    gr::blocks::file_sink::sptr sink_;
-    gr::blocks::throttle::sptr throttle_;
-    uint64_t samples_;
-    int64_t sampling_frequency_;
-    size_t item_size_;
-    std::string filename_;
-    std::string item_type_;
-    std::string dump_filename_;
-    std::string role_;
-    uint32_t in_streams_;
-    uint32_t out_streams_;
-    bool repeat_;
-    bool dump_;
-    // Throttle control
-    bool enable_throttle_control_;
 };
 
 

src/algorithms/signal_source/adapters/osmosdr_signal_source.cc

@@ -18,6 +18,7 @@
 #include "osmosdr_signal_source.h"
 #include "GPS_L1_CA.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include "gnss_sdr_valve.h"
 #include <glog/logging.h>
 #include <gnuradio/blocks/file_sink.h>
@@ -25,9 +26,13 @@
 #include <utility>
 
 
+using namespace std::string_literals;
+
+
 OsmosdrSignalSource::OsmosdrSignalSource(const ConfigurationInterface* configuration,
     const std::string& role, unsigned int in_stream, unsigned int out_stream,
-    Concurrent_Queue<pmt::pmt_t>* queue) : role_(role), in_stream_(in_stream), out_stream_(out_stream)
+    Concurrent_Queue<pmt::pmt_t>* queue)
+    : SignalSourceBase(configuration, role, "Osmosdr_Signal_Source"s), in_stream_(in_stream), out_stream_(out_stream)
 {
     // DUMP PARAMETERS
     const std::string empty;

src/algorithms/signal_source/adapters/osmosdr_signal_source.h

@@ -20,7 +20,7 @@
 #define GNSS_SDR_OSMOSDR_SIGNAL_SOURCE_H
 
 #include "concurrent_queue.h"
-#include "gnss_block_interface.h"
+#include "signal_source_base.h"
 #include <gnuradio/blocks/file_sink.h>
 #include <pmt/pmt.h>
 #include <cstdint>
@@ -42,7 +42,7 @@ class ConfigurationInterface;
  * HackRF or Realtek's RTL2832U-based USB dongle DVB-T receivers
  * (see https://osmocom.org/projects/rtl-sdr/wiki)
  */
-class OsmosdrSignalSource : public GNSSBlockInterface
+class OsmosdrSignalSource : public SignalSourceBase
 {
 public:
     OsmosdrSignalSource(const ConfigurationInterface* configuration,
@@ -51,19 +51,6 @@ public:
 
     ~OsmosdrSignalSource() = default;
 
-    inline std::string role() override
-    {
-        return role_;
-    }
-
-    /*!
-     * \brief Returns "Osmosdr_Signal_Source"
-     */
-    inline std::string implementation() override
-    {
-        return "Osmosdr_Signal_Source";
-    }
-
     inline size_t item_size() override
     {
         return item_size_;
@@ -81,7 +68,6 @@ private:
     gnss_shared_ptr<gr::block> valve_;
     gr::blocks::file_sink::sptr file_sink_;
 
-    std::string role_;
     std::string item_type_;
     std::string dump_filename_;
     std::string osmosdr_args_;

src/algorithms/signal_source/adapters/plutosdr_signal_source.cc

@@ -18,15 +18,20 @@
 #include "plutosdr_signal_source.h"
 #include "GPS_L1_CA.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include "gnss_sdr_valve.h"
 #include <glog/logging.h>
 #include <iostream>
 #include <utility>
 
 
+using namespace std::string_literals;
+
+
 PlutosdrSignalSource::PlutosdrSignalSource(const ConfigurationInterface* configuration,
     const std::string& role, unsigned int in_stream, unsigned int out_stream,
-    Concurrent_Queue<pmt::pmt_t>* queue) : role_(role), in_stream_(in_stream), out_stream_(out_stream)
+    Concurrent_Queue<pmt::pmt_t>* queue)
+    : SignalSourceBase(configuration, role, "Plutosdr_Signal_Source"s), in_stream_(in_stream), out_stream_(out_stream)
 {
     const std::string default_item_type("gr_complex");
     const std::string default_dump_file("./data/signal_source.dat");

src/algorithms/signal_source/adapters/plutosdr_signal_source.h

@@ -19,7 +19,7 @@
 #ifndef GNSS_SDR_PLUTOSDR_SIGNAL_SOURCE_H
 #define GNSS_SDR_PLUTOSDR_SIGNAL_SOURCE_H
 
-#include "gnss_block_interface.h"
+#include "signal_source_base.h"
 #include <gnuradio/blocks/file_sink.h>
 #if GRIIO_INCLUDE_HAS_GNURADIO
 #include <gnuradio/iio/pluto_source.h>
@@ -42,7 +42,7 @@ class ConfigurationInterface;
 
 /*!
  */
-class PlutosdrSignalSource : public GNSSBlockInterface
+class PlutosdrSignalSource : public SignalSourceBase
 {
 public:
     PlutosdrSignalSource(const ConfigurationInterface* configuration,
@@ -51,18 +51,6 @@ public:
 
     ~PlutosdrSignalSource() = default;
 
-    std::string role() override
-    {
-        return role_;
-    }
-
-    /*!
-     * \brief Returns "Plutosdr_Signal_Source"
-     */
-    std::string implementation() override
-    {
-        return "Plutosdr_Signal_Source";
-    }
     size_t item_size() override
     {
         return item_size_;
@@ -79,7 +67,6 @@ private:
     gnss_shared_ptr<gr::block> valve_;
     gr::blocks::file_sink::sptr file_sink_;
 
-    std::string role_;
     std::string dump_filename_;
 
     // Front-end settings

src/algorithms/signal_source/adapters/raw_array_signal_source.cc

@@ -17,14 +17,18 @@
 #include "raw_array_signal_source.h"
 #include "concurrent_queue.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 #include <gnuradio/blocks/file_sink.h>
 #include <pmt/pmt.h>
 #include <dbfcttc/raw_array.h>
 
 
+using namespace std::string_literals;
+
 RawArraySignalSource::RawArraySignalSource(const ConfigurationInterface* configuration,
-    std::string role, unsigned int in_stream, unsigned int out_stream, Concurrent_Queue<pmt::pmt_t>* queue) : role_(role), in_stream_(in_stream), out_stream_(out_stream)
+    std::string role, unsigned int in_stream, unsigned int out_stream, Concurrent_Queue<pmt::pmt_t>* queue)
+    : SignalSourceBase(configuration, role, "Raw_Array_Signal_Source"s), in_stream_(in_stream), out_stream_(out_stream)
 {
     const std::string default_item_type("gr_complex");
     const std::string default_dump_file("./data/raw_array_source.dat");

src/algorithms/signal_source/adapters/raw_array_signal_source.h

@@ -19,7 +19,7 @@
 #define GNSS_SDR_RAW_ARRAY_SIGNAL_SOURCE_H
 
 #include "concurrent_queue.h"
-#include "gnss_block_interface.h"
+#include "signal_source_base.h"
 #include <gnuradio/blocks/file_sink.h>
 #include <gnuradio/hier_block2.h>
 #include <pmt/pmt.h>
@@ -39,7 +39,7 @@ class ConfigurationInterface;
 /*!
  * \brief This class reads samples from a GN3S USB dongle, a RF front-end signal sampler
  */
-class RawArraySignalSource : public GNSSBlockInterface
+class RawArraySignalSource : public SignalSourceBase
 {
 public:
     RawArraySignalSource(const ConfigurationInterface* configuration,
@@ -48,19 +48,6 @@ public:
 
     ~RawArraySignalSource() = default;
 
-    inline std::string role() override
-    {
-        return role_;
-    }
-
-    /*!
-     * \brief Returns "RawArraySignalSource".
-     */
-    inline std::string implementation() override
-    {
-        return "Raw_Array_Signal_Source";
-    }
-
     inline size_t item_size() override
     {
         return item_size_;
@@ -74,12 +61,11 @@ public:
 private:
     gr::block_sptr raw_array_source_;
     gr::blocks::file_sink::sptr file_sink_;
-    std::string role_;
     std::string item_type_;
     std::string dump_filename_;
     std::string eth_device_;
     size_t item_size_;
-    int64_t samples_;
+    [[maybe_unused]] int64_t samples_;
     unsigned int in_stream_;
     unsigned int out_stream_;
     bool dump_;

src/algorithms/signal_source/adapters/rtl_tcp_signal_source.cc

@@ -19,20 +19,21 @@
 #include "rtl_tcp_signal_source.h"
 #include "GPS_L1_CA.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include "gnss_sdr_valve.h"
 #include <glog/logging.h>
 #include <cstdint>
 #include <iostream>
 #include <utility>
 
+using namespace std::string_literals;
 
 RtlTcpSignalSource::RtlTcpSignalSource(const ConfigurationInterface* configuration,
     const std::string& role,
     unsigned int in_stream,
     unsigned int out_stream,
-    Concurrent_Queue<pmt::pmt_t>* queue) : role_(role),
+    Concurrent_Queue<pmt::pmt_t>* queue)
-                                           in_stream_(in_stream),
+    : SignalSourceBase(configuration, role, "RtlTcp_Signal_Source"s), in_stream_(in_stream), out_stream_(out_stream)
-                                           out_stream_(out_stream)
 {
     // DUMP PARAMETERS
     const std::string default_dump_file("./data/signal_source.dat");

src/algorithms/signal_source/adapters/rtl_tcp_signal_source.h

@@ -19,8 +19,8 @@
 #define GNSS_SDR_RTL_TCP_SIGNAL_SOURCE_H
 
 #include "concurrent_queue.h"
-#include "gnss_block_interface.h"
 #include "rtl_tcp_signal_source_c.h"
+#include "signal_source_base.h"
 #include <gnuradio/blocks/deinterleave.h>
 #include <gnuradio/blocks/file_sink.h>
 #include <gnuradio/blocks/float_to_complex.h>
@@ -42,7 +42,7 @@ class ConfigurationInterface;
  * I/Q samples over TCP.
  * (see https://osmocom.org/projects/rtl-sdr/wiki)
  */
-class RtlTcpSignalSource : public GNSSBlockInterface
+class RtlTcpSignalSource : public SignalSourceBase
 {
 public:
     RtlTcpSignalSource(const ConfigurationInterface* configuration,
@@ -53,19 +53,6 @@ public:
 
     ~RtlTcpSignalSource() = default;
 
-    inline std::string role() override
-    {
-        return role_;
-    }
-
-    /*!
-     * \brief Returns "RtlTcp_Signal_Source"
-     */
-    inline std::string implementation() override
-    {
-        return "RtlTcp_Signal_Source";
-    }
-
     inline size_t item_size() override
     {
         return item_size_;
@@ -84,7 +71,6 @@ private:
     gnss_shared_ptr<gr::block> valve_;
     gr::blocks::file_sink::sptr file_sink_;
 
-    std::string role_;
     std::string item_type_;
     std::string dump_filename_;
 

src/algorithms/signal_source/adapters/signal_source_base.cc

@@ -0,0 +1,46 @@
+/*!
+ * \file signal_source_base.cc
+ * \brief Base class for signal sources
+ * \author Jim Melton, 2020. jim.melton(at)sncorp.com
+ *
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
+ * This file is part of GNSS-SDR.
+ *
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * -----------------------------------------------------------------------------
+ */
+
+#include "signal_source_base.h"
+#include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
+#include <utility>  // move
+
+using namespace std::string_literals;
+
+std::string SignalSourceBase::role()
+{
+    return role_;
+}
+
+std::string SignalSourceBase::implementation()
+{
+    return implementation_;
+}
+
+size_t SignalSourceBase::getRfChannels() const
+{
+    return rfChannels_;
+}
+
+SignalSourceBase::SignalSourceBase(ConfigurationInterface const* configuration, std::string role, std::string impl)
+    : role_(std::move(role)), implementation_(std::move(impl))
+{
+    // because clang-tidy insists on using std::move for the string arguments, and to avoid
+    // depending on the order of initialization, assign rfChannels_ in the body
+    rfChannels_ = configuration->property(role_ + ".RF_channels"s, uint64_t(1U));
+}

src/algorithms/signal_source/adapters/signal_source_base.h

@@ -0,0 +1,47 @@
+/*!
+ * \file signal_source_base.h
+ * \brief Header file of the base class to signal_source GNSS blocks.
+ * \author Jim Melton, 2020. jim.melton(at)sncorp.com
+ *
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
+ * This file is part of GNSS-SDR.
+ *
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * -----------------------------------------------------------------------------
+ */
+
+#ifndef GNSS_SDR_SIGNAL_SOURCE_BASE_H
+#define GNSS_SDR_SIGNAL_SOURCE_BASE_H
+
+#include "signal_source_interface.h"
+#include <cstddef>
+#include <string>
+
+
+class ConfigurationInterface;
+
+class SignalSourceBase : public SignalSourceInterface
+{
+public:
+    std::string role() final;
+    std::string implementation() final;
+
+    size_t getRfChannels() const override;
+
+protected:
+    //! Constructor
+    SignalSourceBase(ConfigurationInterface const* configuration, std::string role, std::string impl);
+
+private:
+    std::string const role_;
+    std::string const implementation_;
+    size_t rfChannels_;
+};
+
+
+#endif

src/algorithms/signal_source/adapters/spir_file_signal_source.cc

@@ -6,290 +6,74 @@
  *
  * -----------------------------------------------------------------------------
  *
- * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
- *
  * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
- * This file is not part of GNSS-SDR.
+ * This file is part of GNSS-SDR.
  *
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
  * -----------------------------------------------------------------------------
  */
 
 #include "spir_file_signal_source.h"
-#include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
-#include "gnss_sdr_flags.h"
-#include "gnss_sdr_valve.h"
 #include <glog/logging.h>
-#include <exception>
-#include <fstream>
-#include <iomanip>
-#include <iostream>
-#include <utility>
 
 
+using namespace std::string_literals;
+
 SpirFileSignalSource::SpirFileSignalSource(const ConfigurationInterface* configuration,
     const std::string& role, unsigned int in_streams, unsigned int out_streams,
-    Concurrent_Queue<pmt::pmt_t>* queue) : role_(role), in_streams_(in_streams), out_streams_(out_streams)
+    Concurrent_Queue<pmt::pmt_t>* queue)
+    : FileSourceBase(configuration, role, "Spir_File_Signal_Source"s, queue, "int"s)
 {
-    const std::string default_filename("../data/my_capture.dat");
+    if (in_streams > 0)
-    const std::string default_item_type("int");
-    const std::string default_dump_filename("../data/my_capture_dump.dat");
-
-    samples_ = configuration->property(role + ".samples", static_cast<uint64_t>(0));
-    sampling_frequency_ = configuration->property(role + ".sampling_frequency", static_cast<int64_t>(0));
-    filename_ = configuration->property(role + ".filename", default_filename);
-
-    // override value with commandline flag, if present
-    if (FLAGS_signal_source != "-")
-        {
-            filename_ = FLAGS_signal_source;
-        }
-    if (FLAGS_s != "-")
-        {
-            filename_ = FLAGS_s;
-        }
-
-    item_type_ = configuration->property(role + ".item_type", default_item_type);
-    repeat_ = configuration->property(role + ".repeat", false);
-    dump_ = configuration->property(role + ".dump", false);
-    dump_filename_ = configuration->property(role + ".dump_filename", default_dump_filename);
-    enable_throttle_control_ = configuration->property(role + ".enable_throttle_control", false);
-
-    if (item_type_ == "int")
-        {
-            item_size_ = sizeof(int);
-        }
-    else
-        {
-            LOG(WARNING) << item_type_ << " unrecognized item type. Using int.";
-            item_size_ = sizeof(int);
-        }
-    try
-        {
-            file_source_ = gr::blocks::file_source::make(item_size_, filename_.c_str(), repeat_);
-            unpack_intspir_ = make_unpack_intspir_1bit_samples();
-        }
-    catch (const std::exception& e)
-        {
-            std::cerr
-                << "The receiver was configured to work with a file signal source\n"
-                << "but the specified file is unreachable by GNSS-SDR.\n"
-                << "Please modify your configuration file\n"
-                << "and point SignalSource.filename to a valid raw data file. Then:\n"
-                << "$ gnss-sdr --config_file=/path/to/my_GNSS_SDR_configuration.conf\n"
-                << "Examples of configuration files available at:\n"
-                << GNSSSDR_INSTALL_DIR "/share/gnss-sdr/conf/\n";
-
-            LOG(WARNING) << "file_signal_source: Unable to open the samples file "
-                         << filename_.c_str() << ", exiting the program.";
-            throw(e);
-        }
-
-    DLOG(INFO) << "file_source(" << file_source_->unique_id() << ")";
-
-    if (samples_ == 0)  // read all file
-        {
-            /*!
-             * BUG workaround: The GNU Radio file source does not stop the receiver after reaching the End of File.
-             * A possible solution is to compute the file length in samples using file size, excluding the last 100 milliseconds, and enable always the
-             * valve block
-             */
-            std::ifstream file(filename_.c_str(), std::ios::in | std::ios::binary | std::ios::ate);
-            std::ifstream::pos_type size;
-
-            if (file.is_open())
-                {
-                    size = file.tellg();
-                    LOG(INFO) << "Total samples in the file= " << floor(static_cast<double>(size) / static_cast<double>(item_size()));
-                }
-            else
-                {
-                    std::cout << "file_signal_source: Unable to open the samples file " << filename_.c_str() << '\n';
-                    LOG(ERROR) << "file_signal_source: Unable to open the samples file " << filename_.c_str();
-                }
-            std::streamsize ss = std::cout.precision();
-            std::cout << std::setprecision(16);
-            std::cout << "Processing file " << filename_ << ", which contains " << size << " [bytes]\n";
-            std::cout.precision(ss);
-
-            if (size > 0)
-                {
-                    int sample_packet_factor = 1;  // 1 int -> 1 complex sample (I&Q from 1 channel)
-                    samples_ = floor(static_cast<double>(size) / static_cast<double>(item_size())) * sample_packet_factor;
-                    samples_ = samples_ - ceil(0.002 * static_cast<double>(sampling_frequency_));  // process all the samples available in the file excluding the last 2 ms
-                }
-        }
-
-    CHECK(samples_ > 0) << "File does not contain enough samples to process.";
-    double signal_duration_s = static_cast<double>(samples_) * (1 / static_cast<double>(sampling_frequency_));
-    LOG(INFO) << "Total number samples to be processed= " << samples_ << " GNSS signal duration= " << signal_duration_s << " [s]";
-    std::cout << "GNSS signal recorded time to be processed: " << signal_duration_s << " [s]\n";
-
-    valve_ = gnss_sdr_make_valve(sizeof(float), samples_, queue);
-    DLOG(INFO) << "valve(" << valve_->unique_id() << ")";
-
-    if (dump_)
-        {
-            // sink_ = gr_make_file_sink(item_size_, dump_filename_.c_str());
-            sink_ = gr::blocks::file_sink::make(sizeof(float), dump_filename_.c_str());
-            DLOG(INFO) << "file_sink(" << sink_->unique_id() << ")";
-        }
-
-    if (enable_throttle_control_)
-        {
-            throttle_ = gr::blocks::throttle::make(sizeof(float), sampling_frequency_);
-        }
-    DLOG(INFO) << "File source filename " << filename_;
-    DLOG(INFO) << "Samples " << samples_;
-    DLOG(INFO) << "Sampling frequency " << sampling_frequency_;
-    DLOG(INFO) << "Item type " << item_type_;
-    DLOG(INFO) << "Item size " << item_size_;
-    DLOG(INFO) << "Repeat " << repeat_;
-    DLOG(INFO) << "Dump " << dump_;
-    DLOG(INFO) << "Dump filename " << dump_filename_;
-    if (in_streams_ > 0)
         {
             LOG(ERROR) << "A signal source does not have an input stream";
         }
-    if (out_streams_ > 1)
+    if (out_streams > 1)
         {
             LOG(ERROR) << "This implementation only supports one output stream";
         }
 }
 
-
+std::tuple<size_t, bool> SpirFileSignalSource::itemTypeToSize()
-void SpirFileSignalSource::connect(gr::top_block_sptr top_block)
 {
-    if (samples_ > 0)
+    auto is_complex = false;
+    auto item_size = size_t(0);
+
+    if (item_type() == "int")
         {
-            if (enable_throttle_control_ == true)
+            item_size = sizeof(int);
-                {
-                    top_block->connect(file_source_, 0, unpack_intspir_, 0);
-                    top_block->connect(unpack_intspir_, 0, throttle_, 0);
-                    DLOG(INFO) << "connected file source to throttle";
-                    top_block->connect(throttle_, 0, valve_, 0);
-                    DLOG(INFO) << "connected throttle to valve";
-                    if (dump_)
-                        {
-                            top_block->connect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "connected valve to file sink";
-                        }
-                }
-            else
-                {
-                    top_block->connect(file_source_, 0, unpack_intspir_, 0);
-                    top_block->connect(unpack_intspir_, 0, valve_, 0);
-                    DLOG(INFO) << "connected file source to valve";
-                    if (dump_)
-                        {
-                            top_block->connect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "connected valve to file sink";
-                        }
-                }
         }
     else
         {
-            if (enable_throttle_control_ == true)
+            LOG(WARNING) << item_type() << " unsupported item type. Using int.";
-                {
+            item_size = sizeof(int);
-                    top_block->connect(file_source_, 0, unpack_intspir_, 0);
-                    top_block->connect(unpack_intspir_, 0, throttle_, 0);
-                    DLOG(INFO) << "connected file source to throttle";
-                    if (dump_)
-                        {
-                            top_block->connect(throttle_, 0, sink_, 0);
-                            DLOG(INFO) << "connected file source to sink";
-                        }
-                }
-            else
-                {
-                    if (dump_)
-                        {
-                            top_block->connect(file_source_, 0, unpack_intspir_, 0);
-                            top_block->connect(unpack_intspir_, 0, sink_, 0);
-                            DLOG(INFO) << "connected file source to sink";
-                        }
-                }
         }
+
+    return std::make_tuple(item_size, is_complex);
 }
 
+// This class feeds the file data through a decoder to produce samples; for all intents this is the "source"
+gnss_shared_ptr<gr::block> SpirFileSignalSource::source() const { return unpack_intspir_; }
 
-void SpirFileSignalSource::disconnect(gr::top_block_sptr top_block)
+
+void SpirFileSignalSource::create_file_source_hook()
 {
-    if (samples_ > 0)
+    // connect the file to the decoder
-        {
+    unpack_intspir_ = make_unpack_intspir_1bit_samples();
-            if (enable_throttle_control_ == true)
+    DLOG(INFO) << "unpack_intspir_1bit_samples(" << unpack_intspir_->unique_id() << ")";
-                {
-                    top_block->disconnect(file_source_, 0, unpack_intspir_, 0);
-                    DLOG(INFO) << "disconnected file source to unpack_intspir_";
-                    top_block->connect(unpack_intspir_, 0, throttle_, 0);
-                    DLOG(INFO) << "disconnected unpack_intspir_ to throttle_";
-                    top_block->disconnect(throttle_, 0, valve_, 0);
-                    DLOG(INFO) << "disconnected throttle to valve";
-                    if (dump_)
-                        {
-                            top_block->disconnect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected valve to file sink";
-                        }
-                }
-            else
-                {
-                    top_block->disconnect(file_source_, 0, unpack_intspir_, 0);
-                    DLOG(INFO) << "disconnected file source to unpack_intspir_";
-                    top_block->disconnect(unpack_intspir_, 0, valve_, 0);
-                    DLOG(INFO) << "disconnected unpack_intspir_ to valve";
-                    if (dump_)
-                        {
-                            top_block->disconnect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected valve to file sink";
-                        }
-                }
-        }
-    else
-        {
-            if (enable_throttle_control_ == true)
-                {
-                    top_block->disconnect(file_source_, 0, unpack_intspir_, 0);
-                    DLOG(INFO) << "disconnected file source to unpack_intspir_";
-                    top_block->disconnect(unpack_intspir_, 0, throttle_, 0);
-                    DLOG(INFO) << "disconnected unpack_intspir_ to throttle";
-                    if (dump_)
-                        {
-                            top_block->disconnect(unpack_intspir_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected funpack_intspir_ to sink";
-                        }
-                }
-            else
-                {
-                    if (dump_)
-                        {
-                            top_block->disconnect(file_source_, 0, unpack_intspir_, 0);
-                            DLOG(INFO) << "disconnected file source to unpack_intspir_";
-                            top_block->disconnect(unpack_intspir_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected unpack_intspir_ to sink";
-                        }
-                }
-        }
 }
 
-
+void SpirFileSignalSource::pre_connect_hook(gr::top_block_sptr top_block)
-gr::basic_block_sptr SpirFileSignalSource::get_left_block()
 {
-    LOG(WARNING) << "Left block of a signal source should not be retrieved";
+    top_block->connect(file_source(), 0, unpack_intspir_, 0);
-    // return gr_block_sptr();
+    DLOG(INFO) << "connected file_source to unpacker";
-    return gr::blocks::file_source::sptr();
 }
 
-
+void SpirFileSignalSource::post_disconnect_hook(gr::top_block_sptr top_block)
-gr::basic_block_sptr SpirFileSignalSource::get_right_block()
 {
-    if (samples_ > 0)
+    top_block->disconnect(file_source(), 0, unpack_intspir_, 0);
-        {
+    DLOG(INFO) << "disconnected file_source from unpacker";
-            return valve_;
-        }
-    if (enable_throttle_control_ == true)
-        {
-            return throttle_;
-        }
-    return unpack_intspir_;
 }

src/algorithms/signal_source/adapters/spir_file_signal_source.h

@@ -6,13 +6,10 @@
  *
  * -----------------------------------------------------------------------------
  *
- * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
+ * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
- *
+ * This file is part of GNSS-SDR.
- * GNSS-SDR is a software defined Global Navigation
- *          Satellite Systems receiver
- *
- * This file is not part of GNSS-SDR.
  *
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
  * -----------------------------------------------------------------------------
@@ -21,16 +18,8 @@
 #ifndef GNSS_SDR_SPIR_FILE_SIGNAL_SOURCE_H
 #define GNSS_SDR_SPIR_FILE_SIGNAL_SOURCE_H
 
-#include "concurrent_queue.h"
+#include "file_source_base.h"
-#include "gnss_block_interface.h"
 #include "unpack_intspir_1bit_samples.h"
-#include <gnuradio/blocks/file_sink.h>
-#include <gnuradio/blocks/file_source.h>
-#include <gnuradio/blocks/throttle.h>
-#include <gnuradio/hier_block2.h>
-#include <pmt/pmt.h>
-#include <cstdint>
-#include <string>
 
 
 /** \addtogroup Signal_Source
@@ -45,7 +34,7 @@ class ConfigurationInterface;
  * \brief Class that reads signals samples from a file
  * and adapts it to a SignalSourceInterface
  */
-class SpirFileSignalSource : public GNSSBlockInterface
+class SpirFileSignalSource : public FileSourceBase
 {
 public:
     SpirFileSignalSource(const ConfigurationInterface* configuration, const std::string& role,
@@ -54,77 +43,16 @@ public:
 
     ~SpirFileSignalSource() = default;
 
-    inline std::string role() override
+protected:
-    {
+    std::tuple<size_t, bool> itemTypeToSize() override;
-        return role_;
+    gnss_shared_ptr<gr::block> source() const override;
-    }
+    void create_file_source_hook() override;
+    void pre_connect_hook(gr::top_block_sptr top_block) override;
+    void post_disconnect_hook(gr::top_block_sptr top_block) override;
 
-    /*!
-     * \brief Returns "Spir_File_Signal_Source".
-     */
-    inline std::string implementation() override
-    {
-        return "Spir_File_Signal_Source";
-    }
-
-    inline size_t item_size() override
-    {
-        return item_size_;
-    }
-
-    void connect(gr::top_block_sptr top_block) override;
-    void disconnect(gr::top_block_sptr top_block) override;
-    gr::basic_block_sptr get_left_block() override;
-    gr::basic_block_sptr get_right_block() override;
-
-    inline std::string filename() const
-    {
-        return filename_;
-    }
-
-    inline std::string item_type() const
-    {
-        return item_type_;
-    }
-
-    inline bool repeat() const
-    {
-        return repeat_;
-    }
-
-    inline int64_t sampling_frequency() const
-    {
-        return sampling_frequency_;
-    }
-
-    inline uint64_t samples() const
-    {
-        return samples_;
-    }
 
 private:
-    gr::blocks::file_source::sptr file_source_;
     unpack_intspir_1bit_samples_sptr unpack_intspir_;
-    gnss_shared_ptr<gr::block> valve_;
-    gr::blocks::file_sink::sptr sink_;
-    gr::blocks::throttle::sptr throttle_;
-    std::string filename_;
-    std::string item_type_;
-    std::string dump_filename_;
-    std::string role_;
-
-    uint64_t samples_;
-    int64_t sampling_frequency_;
-    size_t item_size_;
-
-    unsigned int in_streams_;
-    unsigned int out_streams_;
-
-    bool repeat_;
-    bool dump_;
-
-    // Throttle control
-    bool enable_throttle_control_;
 };
 
 

src/algorithms/signal_source/adapters/spir_gss6450_file_signal_source.cc

@@ -18,6 +18,7 @@
 
 #include "spir_gss6450_file_signal_source.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 #include <exception>
 #include <fstream>
@@ -25,9 +26,11 @@
 #include <iostream>
 #include <utility>
 
+using namespace std::string_literals;
 
 SpirGSS6450FileSignalSource::SpirGSS6450FileSignalSource(const ConfigurationInterface* configuration,
-    const std::string& role, uint32_t in_streams, uint32_t out_streams, Concurrent_Queue<pmt::pmt_t>* queue) : role_(role), in_streams_(in_streams), out_streams_(out_streams)
+    const std::string& role, uint32_t in_streams, uint32_t out_streams, Concurrent_Queue<pmt::pmt_t>* queue)
+    : SignalSourceBase(configuration, role, "Spir_GSS6450_File_Signal_Source"s), in_streams_(in_streams), out_streams_(out_streams)
 {
     const std::string default_filename("../data/my_capture.dat");
     const std::string default_dump_filename("../data/my_capture_dump.dat");

src/algorithms/signal_source/adapters/spir_gss6450_file_signal_source.h

@@ -22,8 +22,8 @@
 #define GNSS_SDR_SPIR_GSS6450_FILE_SIGNAL_SOURCE_H
 
 #include "concurrent_queue.h"
-#include "gnss_block_interface.h"
 #include "gnss_sdr_valve.h"
+#include "signal_source_base.h"
 #include "unpack_spir_gss6450_samples.h"
 #include <gnuradio/blocks/deinterleave.h>
 #include <gnuradio/blocks/endian_swap.h>
@@ -50,23 +50,12 @@ class ConfigurationInterface;
  * \brief Class that reads signals samples from a file
  * and adapts it to a SignalSourceInterface
  */
-class SpirGSS6450FileSignalSource : public GNSSBlockInterface
+class SpirGSS6450FileSignalSource : public SignalSourceBase
 {
 public:
     SpirGSS6450FileSignalSource(const ConfigurationInterface* configuration, const std::string& role,
         uint32_t in_streams, uint32_t out_streams, Concurrent_Queue<pmt::pmt_t>* queue);
 
-    ~SpirGSS6450FileSignalSource() = default;
-    inline std::string role() override
-    {
-        return role_;
-    }
-
-    inline std::string implementation() override
-    {
-        return "Spir_GSS6450_File_Signal_Source";
-    }
-
     inline size_t item_size() override
     {
         return item_size_;
@@ -114,7 +103,6 @@ private:
     std::vector<gr::blocks::throttle::sptr> throttle_vec_;
     std::string filename_;
     std::string dump_filename_;
-    std::string role_;
     std::string item_type_;
     uint64_t samples_;
     int64_t sampling_frequency_;

src/algorithms/signal_source/adapters/two_bit_cpx_file_signal_source.cc

@@ -9,296 +9,77 @@
  * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
  * This file is part of GNSS-SDR.
  *
- * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
  * -----------------------------------------------------------------------------
  */
 
 #include "two_bit_cpx_file_signal_source.h"
-#include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
-#include "gnss_sdr_flags.h"
-#include "gnss_sdr_valve.h"
 #include <glog/logging.h>
-#include <exception>
+
-#include <fstream>
+using namespace std::string_literals;
-#include <iomanip>
-#include <iostream>
-#include <utility>
 
 
 TwoBitCpxFileSignalSource::TwoBitCpxFileSignalSource(
     const ConfigurationInterface* configuration,
     const std::string& role,
-    unsigned int in_streams,
+    unsigned int in_streams, unsigned int out_streams,
-    unsigned int out_streams,
+    Concurrent_Queue<pmt::pmt_t>* queue)
-    Concurrent_Queue<pmt::pmt_t>* queue) : role_(role),
+    : FileSourceBase(configuration, role, "Two_Bit_Cpx_File_Signal_Source"s, queue, "byte"s)
-                                           in_streams_(in_streams),
-                                           out_streams_(out_streams)
 {
-    const std::string default_filename("../data/my_capture.dat");
+    if (in_streams > 0)
-    const std::string default_item_type("byte");
-    const std::string default_dump_filename("../data/my_capture_dump.dat");
-
-    samples_ = configuration->property(role + ".samples", static_cast<uint64_t>(0));
-    sampling_frequency_ = configuration->property(role + ".sampling_frequency", static_cast<int64_t>(0));
-    filename_ = configuration->property(role + ".filename", default_filename);
-
-    // override value with commandline flag, if present
-    if (FLAGS_signal_source != "-")
-        {
-            filename_ = FLAGS_signal_source;
-        }
-    if (FLAGS_s != "-")
-        {
-            filename_ = FLAGS_s;
-        }
-
-    item_type_ = configuration->property(role + ".item_type", default_item_type);
-    repeat_ = configuration->property(role + ".repeat", false);
-    dump_ = configuration->property(role + ".dump", false);
-    dump_filename_ = configuration->property(role + ".dump_filename", default_dump_filename);
-    enable_throttle_control_ = configuration->property(role + ".enable_throttle_control", false);
-
-    if (item_type_ == "byte")
-        {
-            item_size_ = sizeof(char);
-        }
-    else
-        {
-            LOG(WARNING) << item_type_ << " unrecognized item type. Using byte.";
-            item_size_ = sizeof(char);
-        }
-    try
-        {
-            file_source_ = gr::blocks::file_source::make(item_size_, filename_.c_str(), repeat_);
-            unpack_byte_ = make_unpack_byte_2bit_cpx_samples();
-            inter_shorts_to_cpx_ = gr::blocks::interleaved_short_to_complex::make(false, true);  // I/Q swap enabled
-        }
-    catch (const std::exception& e)
-        {
-            std::cerr
-                << "The receiver was configured to work with a file signal source\n"
-                << "but the specified file is unreachable by GNSS-SDR.\n"
-                << "Please modify your configuration file\n"
-                << "and point SignalSource.filename to a valid raw data file. Then:\n"
-                << "$ gnss-sdr --config_file=/path/to/my_GNSS_SDR_configuration.conf\n"
-                << "Examples of configuration files available at:\n"
-                << GNSSSDR_INSTALL_DIR "/share/gnss-sdr/conf/\n";
-
-            LOG(WARNING) << "file_signal_source: Unable to open the samples file "
-                         << filename_.c_str() << ", exiting the program.";
-            throw(e);
-        }
-
-    DLOG(INFO) << "file_source(" << file_source_->unique_id() << ")";
-
-    if (samples_ == 0)  // read all file
-        {
-            /*!
-             * BUG workaround: The GNU Radio file source does not stop the receiver after reaching the End of File.
-             * A possible solution is to compute the file length in samples using file size, excluding the last 2 milliseconds, and enable always the
-             * valve block
-             */
-            std::ifstream file(filename_.c_str(), std::ios::in | std::ios::binary | std::ios::ate);
-            std::ifstream::pos_type size;
-
-            if (file.is_open())
-                {
-                    size = file.tellg();
-                    LOG(INFO) << "Total samples in the file= " << floor(static_cast<double>(size) / static_cast<double>(item_size()));
-                }
-            else
-                {
-                    std::cout << "file_signal_source: Unable to open the samples file " << filename_.c_str() << '\n';
-                    LOG(ERROR) << "file_signal_source: Unable to open the samples file " << filename_.c_str();
-                }
-            std::streamsize ss = std::cout.precision();
-            std::cout << std::setprecision(16);
-            std::cout << "Processing file " << filename_ << ", which contains " << size << " [bytes]\n";
-            std::cout.precision(ss);
-
-            if (size > 0)
-                {
-                    int sample_packet_factor = 2;  // 1 byte -> 2 samples
-                    samples_ = floor(static_cast<double>(size) / static_cast<double>(item_size())) * sample_packet_factor;
-                    samples_ = samples_ - ceil(0.002 * static_cast<double>(sampling_frequency_));  // process all the samples available in the file excluding the last 2 ms
-                }
-        }
-
-    CHECK(samples_ > 0) << "File does not contain enough samples to process.";
-    const double signal_duration_s = static_cast<double>(samples_) * (1 / static_cast<double>(sampling_frequency_));
-    LOG(INFO) << "Total number samples to be processed= " << samples_ << " GNSS signal duration= " << signal_duration_s << " [s]";
-    std::cout << "GNSS signal recorded time to be processed: " << signal_duration_s << " [s]\n";
-
-    valve_ = gnss_sdr_make_valve(sizeof(gr_complex), samples_, queue);
-    DLOG(INFO) << "valve(" << valve_->unique_id() << ")";
-
-    if (dump_)
-        {
-            // sink_ = gr_make_file_sink(item_size_, dump_filename_.c_str());
-            sink_ = gr::blocks::file_sink::make(sizeof(gr_complex), dump_filename_.c_str());
-            DLOG(INFO) << "file_sink(" << sink_->unique_id() << ")";
-        }
-
-    if (enable_throttle_control_)
-        {
-            throttle_ = gr::blocks::throttle::make(sizeof(gr_complex), sampling_frequency_);
-        }
-    DLOG(INFO) << "File source filename " << filename_;
-    DLOG(INFO) << "Samples " << samples_;
-    DLOG(INFO) << "Sampling frequency " << sampling_frequency_;
-    DLOG(INFO) << "Item type " << item_type_;
-    DLOG(INFO) << "Item size " << item_size_;
-    DLOG(INFO) << "Repeat " << repeat_;
-    DLOG(INFO) << "Dump " << dump_;
-    DLOG(INFO) << "Dump filename " << dump_filename_;
-    if (in_streams_ > 0)
         {
             LOG(ERROR) << "A signal source does not have an input stream";
         }
-    if (out_streams_ > 1)
+    if (out_streams > 1)
         {
             LOG(ERROR) << "This implementation only supports one output stream";
         }
 }
 
 
-void TwoBitCpxFileSignalSource::connect(gr::top_block_sptr top_block)
+std::tuple<size_t, bool> TwoBitCpxFileSignalSource::itemTypeToSize()
 {
-    if (samples_ > 0)
+    auto is_complex = false;
+    auto item_size = size_t(sizeof(char));  // default
+
+    if (item_type() == "byte")
         {
-            if (enable_throttle_control_ == true)
+            item_size = sizeof(char);
-                {
-                    top_block->connect(file_source_, 0, unpack_byte_, 0);
-                    top_block->connect(unpack_byte_, 0, inter_shorts_to_cpx_, 0);
-                    top_block->connect(inter_shorts_to_cpx_, 0, throttle_, 0);
-                    DLOG(INFO) << "connected file source to throttle";
-                    top_block->connect(throttle_, 0, valve_, 0);
-                    DLOG(INFO) << "connected throttle to valve";
-                    if (dump_)
-                        {
-                            top_block->connect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "connected valve to file sink";
-                        }
-                }
-            else
-                {
-                    top_block->connect(file_source_, 0, unpack_byte_, 0);
-                    top_block->connect(unpack_byte_, 0, inter_shorts_to_cpx_, 0);
-                    top_block->connect(inter_shorts_to_cpx_, 0, valve_, 0);
-                    DLOG(INFO) << "connected file source to valve";
-                    if (dump_)
-                        {
-                            top_block->connect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "connected valve to file sink";
-                        }
-                }
         }
     else
         {
-            if (enable_throttle_control_ == true)
+            LOG(WARNING) << item_type() << " unrecognized item type. Using byte.";
-                {
-                    top_block->connect(file_source_, 0, unpack_byte_, 0);
-                    top_block->connect(unpack_byte_, 0, inter_shorts_to_cpx_, 0);
-                    top_block->connect(inter_shorts_to_cpx_, 0, throttle_, 0);
-                    DLOG(INFO) << "connected file source to throttle";
-                    if (dump_)
-                        {
-                            top_block->connect(throttle_, 0, sink_, 0);
-                            DLOG(INFO) << "connected file source to sink";
-                        }
-                }
-            else
-                {
-                    if (dump_)
-                        {
-                            top_block->connect(file_source_, 0, unpack_byte_, 0);
-                            top_block->connect(unpack_byte_, 0, inter_shorts_to_cpx_, 0);
-                            top_block->connect(inter_shorts_to_cpx_, 0, sink_, 0);
-                            DLOG(INFO) << "connected file source to sink";
-                        }
-                }
         }
+
+    return std::make_tuple(item_size, is_complex);
 }
 
+// 1 byte -> 2 samples
+double TwoBitCpxFileSignalSource::packetsPerSample() const { return 2.0; }
+gnss_shared_ptr<gr::block> TwoBitCpxFileSignalSource::source() const { return inter_shorts_to_cpx_; }
 
-void TwoBitCpxFileSignalSource::disconnect(gr::top_block_sptr top_block)
+
+void TwoBitCpxFileSignalSource::create_file_source_hook()
 {
-    if (samples_ > 0)
+    unpack_byte_ = make_unpack_byte_2bit_cpx_samples();
-        {
+    DLOG(INFO) << "unpack_byte_2bit_cpx_samples(" << unpack_byte_->unique_id() << ")";
-            if (enable_throttle_control_ == true)
+    inter_shorts_to_cpx_ = gr::blocks::interleaved_short_to_complex::make(false, true);  // I/Q swap enabled
-                {
+    DLOG(INFO) << "interleaved_short_to_complex(" << inter_shorts_to_cpx_->unique_id() << ")";
-                    top_block->disconnect(file_source_, 0, unpack_byte_, 0);
-                    DLOG(INFO) << "disconnected file source to unpack_byte_";
-                    top_block->connect(unpack_byte_, 0, throttle_, 0);
-                    DLOG(INFO) << "disconnected unpack_byte_ to throttle_";
-                    top_block->disconnect(throttle_, 0, valve_, 0);
-                    DLOG(INFO) << "disconnected throttle to valve";
-                    if (dump_)
-                        {
-                            top_block->disconnect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected valve to file sink";
-                        }
-                }
-            else
-                {
-                    top_block->disconnect(file_source_, 0, unpack_byte_, 0);
-                    DLOG(INFO) << "disconnected file source to unpack_byte_";
-                    top_block->disconnect(unpack_byte_, 0, valve_, 0);
-                    DLOG(INFO) << "disconnected unpack_byte_ to valve";
-                    if (dump_)
-                        {
-                            top_block->disconnect(valve_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected valve to file sink";
-                        }
-                }
-        }
-    else
-        {
-            if (enable_throttle_control_ == true)
-                {
-                    top_block->disconnect(file_source_, 0, unpack_byte_, 0);
-                    DLOG(INFO) << "disconnected file source to unpack_byte_";
-                    top_block->disconnect(unpack_byte_, 0, throttle_, 0);
-                    DLOG(INFO) << "disconnected unpack_byte_ to throttle";
-                    if (dump_)
-                        {
-                            top_block->disconnect(unpack_byte_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected funpack_byte_ to sink";
-                        }
-                }
-            else
-                {
-                    if (dump_)
-                        {
-                            top_block->disconnect(file_source_, 0, unpack_byte_, 0);
-                            DLOG(INFO) << "disconnected file source to unpack_byte_";
-                            top_block->disconnect(unpack_byte_, 0, sink_, 0);
-                            DLOG(INFO) << "disconnected unpack_byte_ to sink";
-                        }
-                }
-        }
 }
 
-
+void TwoBitCpxFileSignalSource::pre_connect_hook(gr::top_block_sptr top_block)
-gr::basic_block_sptr TwoBitCpxFileSignalSource::get_left_block()
 {
-    LOG(WARNING) << "Left block of a signal source should not be retrieved";
+    top_block->connect(file_source(), 0, unpack_byte_, 0);
-    // return gr_block_sptr();
+    top_block->connect(unpack_byte_, 0, inter_shorts_to_cpx_, 0);
-    return gr::blocks::file_source::sptr();
+    DLOG(INFO) << "connected file_source to unpacker";
 }
 
-
+void TwoBitCpxFileSignalSource::pre_disconnect_hook(gr::top_block_sptr top_block)
-gr::basic_block_sptr TwoBitCpxFileSignalSource::get_right_block()
 {
-    if (samples_ > 0)
+    top_block->disconnect(file_source(), 0, unpack_byte_, 0);
-        {
+    top_block->disconnect(unpack_byte_, 0, inter_shorts_to_cpx_, 0);
-            return valve_;
+    DLOG(INFO) << "disconnected file_source from unpacker";
-        }
-    if (enable_throttle_control_ == true)
-        {
-            return throttle_;
-        }
-    return unpack_byte_;
 }

src/algorithms/signal_source/adapters/two_bit_cpx_file_signal_source.h

@@ -11,7 +11,7 @@
  * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
  * This file is part of GNSS-SDR.
  *
- * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
  * -----------------------------------------------------------------------------
@@ -20,17 +20,9 @@
 #ifndef GNSS_SDR_TWO_BIT_CPX_FILE_SIGNAL_SOURCE_H
 #define GNSS_SDR_TWO_BIT_CPX_FILE_SIGNAL_SOURCE_H
 
-#include "concurrent_queue.h"
+#include "file_source_base.h"
-#include "gnss_block_interface.h"
 #include "unpack_byte_2bit_cpx_samples.h"
-#include <gnuradio/blocks/file_sink.h>
-#include <gnuradio/blocks/file_source.h>
 #include <gnuradio/blocks/interleaved_short_to_complex.h>
-#include <gnuradio/blocks/throttle.h>
-#include <gnuradio/hier_block2.h>
-#include <pmt/pmt.h>
-#include <cstdint>
-#include <string>
 
 /** \addtogroup Signal_Source
  * \{ */
@@ -44,7 +36,7 @@ class ConfigurationInterface;
  * \brief Class that reads signals samples from a file
  * and adapts it to a SignalSourceInterface
  */
-class TwoBitCpxFileSignalSource : public GNSSBlockInterface
+class TwoBitCpxFileSignalSource : public FileSourceBase
 {
 public:
     TwoBitCpxFileSignalSource(const ConfigurationInterface* configuration,
@@ -54,74 +46,18 @@ public:
         Concurrent_Queue<pmt::pmt_t>* queue);
 
     ~TwoBitCpxFileSignalSource() = default;
-    inline std::string role() override
-    {
-        return role_;
-    }
 
-    /*!
+protected:
-     * \brief Returns "Two_Bit_Cpx_File_Signal_Source".
+    std::tuple<size_t, bool> itemTypeToSize() override;
-     */
+    double packetsPerSample() const override;
-    inline std::string implementation() override
+    gnss_shared_ptr<gr::block> source() const override;
-    {
+    void create_file_source_hook() override;
-        return "Two_Bit_Cpx_File_Signal_Source";
+    void pre_connect_hook(gr::top_block_sptr top_block) override;
-    }
+    void pre_disconnect_hook(gr::top_block_sptr top_block) override;
-
-    inline size_t item_size() override
-    {
-        return item_size_;
-    }
-
-    void connect(gr::top_block_sptr top_block) override;
-    void disconnect(gr::top_block_sptr top_block) override;
-    gr::basic_block_sptr get_left_block() override;
-    gr::basic_block_sptr get_right_block() override;
-
-    inline std::string filename() const
-    {
-        return filename_;
-    }
-
-    inline std::string item_type() const
-    {
-        return item_type_;
-    }
-
-    inline bool repeat() const
-    {
-        return repeat_;
-    }
-
-    inline int64_t sampling_frequency() const
-    {
-        return sampling_frequency_;
-    }
-
-    inline uint64_t samples() const
-    {
-        return samples_;
-    }
 
 private:
-    gr::blocks::file_source::sptr file_source_;
-    gr::blocks::interleaved_short_to_complex::sptr inter_shorts_to_cpx_;
     unpack_byte_2bit_cpx_samples_sptr unpack_byte_;
-    gnss_shared_ptr<gr::block> valve_;
+    gr::blocks::interleaved_short_to_complex::sptr inter_shorts_to_cpx_;
-    gr::blocks::file_sink::sptr sink_;
-    gr::blocks::throttle::sptr throttle_;
-    std::string filename_;
-    std::string item_type_;
-    std::string dump_filename_;
-    std::string role_;
-    size_t item_size_;
-    uint64_t samples_;
-    int64_t sampling_frequency_;
-    unsigned int in_streams_;
-    unsigned int out_streams_;
-    bool repeat_;
-    bool dump_;
-    // Throttle control
-    bool enable_throttle_control_;
 };
 
 

src/algorithms/signal_source/adapters/two_bit_packed_file_signal_source.cc

@@ -10,7 +10,7 @@
  * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
  * This file is part of GNSS-SDR.
  *
- * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
  * -----------------------------------------------------------------------------
@@ -18,291 +18,122 @@
 
 #include "two_bit_packed_file_signal_source.h"
 #include "configuration_interface.h"
-#include "gnss_sdr_flags.h"
+#include "gnss_sdr_string_literals.h"
-#include "gnss_sdr_valve.h"
 #include <glog/logging.h>
 #include <gnuradio/blocks/char_to_float.h>
-#include <exception>
-#include <fstream>
-#include <iomanip>
-#include <iostream>
-#include <utility>
 
+using namespace std::string_literals;
 
 TwoBitPackedFileSignalSource::TwoBitPackedFileSignalSource(
     const ConfigurationInterface* configuration,
     const std::string& role,
     unsigned int in_streams,
     unsigned int out_streams,
-    Concurrent_Queue<pmt::pmt_t>* queue) : role_(role),
+    Concurrent_Queue<pmt::pmt_t>* queue)
-                                           in_streams_(in_streams),
+    : FileSourceBase(configuration, role, "Two_Bit_Packed_File_Signal_Source"s, queue, "byte"s), sample_type_(configuration->property(role + ".sample_type", "real"s)),  // options: "real", "iq", "qi"
-                                           out_streams_(out_streams)
+      big_endian_items_(configuration->property(role + ".big_endian_items", true)),
+      big_endian_bytes_(configuration->property(role + ".big_endian_bytes", false)),
+      reverse_interleaving_(false)
 {
-    const std::string default_filename("../data/my_capture.dat");
+    if (in_streams > 0)
-    const std::string default_item_type("byte");
-    const std::string default_dump_filename("../data/my_capture_dump.dat");
-    const std::string default_sample_type("real");
-    const double default_seconds_to_skip = 0.0;
-
-    samples_ = configuration->property(role + ".samples", static_cast<uint64_t>(0));
-    sampling_frequency_ = configuration->property(role + ".sampling_frequency", static_cast<int64_t>(0));
-    filename_ = configuration->property(role + ".filename", default_filename);
-
-    // override value with commandline flag, if present
-    if (FLAGS_signal_source != "-")
-        {
-            filename_ = FLAGS_signal_source;
-        }
-    if (FLAGS_s != "-")
-        {
-            filename_ = FLAGS_s;
-        }
-
-    item_type_ = configuration->property(role + ".item_type", default_item_type);
-    big_endian_items_ = configuration->property(role + ".big_endian_items", true);
-    big_endian_bytes_ = configuration->property(role + ".big_endian_bytes", false);
-    sample_type_ = configuration->property(role + ".sample_type", default_sample_type);  // options: "real", "iq", "qi"
-    repeat_ = configuration->property(role + ".repeat", false);
-    dump_ = configuration->property(role + ".dump", false);
-    dump_filename_ = configuration->property(role + ".dump_filename", default_dump_filename);
-    enable_throttle_control_ = configuration->property(role + ".enable_throttle_control", false);
-    const double seconds_to_skip = configuration->property(role + ".seconds_to_skip", default_seconds_to_skip);
-    int64_t bytes_to_skip = 0;
-
-    if (item_type_ == "byte")
-        {
-            item_size_ = sizeof(char);
-        }
-    else if (item_type_ == "short")
-        {
-            // If we have shorts stored in little endian format, might as
-            // well read them in as bytes.
-            if (big_endian_items_)
-                {
-                    item_size_ = sizeof(int16_t);
-                }
-            else
-                {
-                    item_size_ = sizeof(char);
-                }
-        }
-    else
-        {
-            LOG(WARNING) << item_type_ << " unrecognized item type. Using byte.";
-            item_size_ = sizeof(char);
-        }
-
-    reverse_interleaving_ = false;
-    is_complex_ = true;
-    if (sample_type_ == "real")
-        {
-            is_complex_ = false;
-        }
-    else if (sample_type_ == "iq")
-        {
-            is_complex_ = true;
-        }
-    else if (sample_type_ == "qi")
-        {
-            is_complex_ = true;
-            reverse_interleaving_ = true;
-        }
-    else
-        {
-            LOG(WARNING) << sample_type_ << " unrecognized sample type. Assuming: "
-                         << (is_complex_ ? (reverse_interleaving_ ? "qi" : "iq") : "real");
-        }
-    try
-        {
-            file_source_ = gr::blocks::file_source::make(item_size_, filename_.c_str(), repeat_);
-
-            if (seconds_to_skip > 0)
-                {
-                    bytes_to_skip = static_cast<int64_t>(
-                        seconds_to_skip * sampling_frequency_ / 4);
-                    if (is_complex_)
-                        {
-                            bytes_to_skip <<= 1;
-                        }
-                    file_source_->seek(bytes_to_skip, SEEK_SET);
-                }
-
-            unpack_samples_ = make_unpack_2bit_samples(big_endian_bytes_,
-                item_size_, big_endian_items_, reverse_interleaving_);
-            if (is_complex_)
-                {
-                    char_to_float_ =
-                        gr::blocks::interleaved_char_to_complex::make(false);
-                }
-            else
-                {
-                    char_to_float_ =
-                        gr::blocks::char_to_float::make();
-                }
-        }
-    catch (const std::exception& e)
-        {
-            std::cerr
-                << "The receiver was configured to work with a file signal source\n"
-                << "but the specified file is unreachable by GNSS-SDR.\n"
-                << "Please modify your configuration file\n"
-                << "and point SignalSource.filename to a valid raw data file. Then:\n"
-                << "$ gnss-sdr --config_file=/path/to/my_GNSS_SDR_configuration.conf\n"
-                << "Examples of configuration files available at:\n"
-                << GNSSSDR_INSTALL_DIR "/share/gnss-sdr/conf/\n";
-
-            LOG(WARNING) << "file_signal_source: Unable to open the samples file "
-                         << filename_.c_str() << ", exiting the program.";
-            throw(e);
-        }
-
-    DLOG(INFO) << "file_source(" << file_source_->unique_id() << ")";
-
-    const size_t output_item_size = (is_complex_ ? sizeof(gr_complex) : sizeof(float));
-
-    if (samples_ == 0)  // read all file
-        {
-            /*!
-             * BUG workaround: The GNU Radio file source does not stop the receiver after reaching the End of File.
-             * A possible solution is to compute the file length in samples using file size, excluding the last 2 milliseconds, and enable always the
-             * valve block
-             */
-            std::ifstream file(filename_.c_str(), std::ios::in | std::ios::binary | std::ios::ate);
-            std::ifstream::pos_type size;
-
-            if (file.is_open())
-                {
-                    size = file.tellg();
-                    samples_ = floor(static_cast<double>(size) * (is_complex_ ? 2.0 : 4.0));
-                    LOG(INFO) << "Total samples in the file= " << samples_;  // 4 samples per byte
-                    samples_ -= bytes_to_skip;
-
-                    // Also skip the last two milliseconds:
-                    samples_ -= ceil(0.002 * sampling_frequency_ / (is_complex_ ? 2.0 : 4.0));
-                }
-            else
-                {
-                    std::cout << "file_signal_source: Unable to open the samples file " << filename_.c_str() << '\n';
-                    LOG(ERROR) << "file_signal_source: Unable to open the samples file " << filename_.c_str();
-                }
-            std::streamsize ss = std::cout.precision();
-            std::cout << std::setprecision(16);
-            std::cout << "Processing file " << filename_ << ", which contains " << size << " [bytes]\n";
-            std::cout.precision(ss);
-        }
-
-    CHECK(samples_ > 0) << "File does not contain enough samples to process.";
-    double signal_duration_s;
-    signal_duration_s = static_cast<double>(samples_) * (1 / static_cast<double>(sampling_frequency_));
-    LOG(INFO) << "Total number samples to be processed= " << samples_ << " GNSS signal duration= " << signal_duration_s << " [s]";
-    std::cout << "GNSS signal recorded time to be processed: " << signal_duration_s << " [s]\n";
-
-    valve_ = gnss_sdr_make_valve(output_item_size, samples_, queue);
-    DLOG(INFO) << "valve(" << valve_->unique_id() << ")";
-
-    if (dump_)
-        {
-            // sink_ = gr_make_file_sink(item_size_, dump_filename_.c_str());
-            sink_ = gr::blocks::file_sink::make(output_item_size, dump_filename_.c_str());
-            DLOG(INFO) << "file_sink(" << sink_->unique_id() << ")";
-        }
-
-    if (enable_throttle_control_)
-        {
-            throttle_ = gr::blocks::throttle::make(output_item_size, sampling_frequency_);
-        }
-    DLOG(INFO) << "File source filename " << filename_;
-    DLOG(INFO) << "Samples " << samples_;
-    DLOG(INFO) << "Sampling frequency " << sampling_frequency_;
-    DLOG(INFO) << "Item type " << item_type_;
-    DLOG(INFO) << "Item size " << item_size_;
-    DLOG(INFO) << "Repeat " << repeat_;
-    DLOG(INFO) << "Dump " << dump_;
-    DLOG(INFO) << "Dump filename " << dump_filename_;
-    if (in_streams_ > 0)
         {
             LOG(ERROR) << "A signal source does not have an input stream";
         }
-    if (out_streams_ > 1)
+    if (out_streams > 1)
         {
             LOG(ERROR) << "This implementation only supports one output stream";
         }
 }
 
 
-void TwoBitPackedFileSignalSource::connect(gr::top_block_sptr top_block)
+std::tuple<size_t, bool> TwoBitPackedFileSignalSource::itemTypeToSize()
 {
-    gr::basic_block_sptr left_block = file_source_;
+    auto is_complex_t = false;
-    gr::basic_block_sptr right_block = unpack_samples_;
+    auto item_size = size_t(sizeof(char));  // default
 
-    top_block->connect(file_source_, 0, unpack_samples_, 0);
+    if (item_type() == "byte")
-    left_block = right_block;
+        {
+            item_size = sizeof(char);
+        }
+    else if (item_type() == "short")
+        {
+            // If we have shorts stored in little endian format, might as
+            // well read them in as bytes.
+            // TODO: this seems to make assumptions about the endianness of this machine
+            if (big_endian_items_)
+                {
+                    item_size = sizeof(int16_t);
+                }
+            else
+                {
+                    // how can this be right? the number of samples is computed based on this value
+                    item_size = sizeof(char);
+                }
+        }
+    else
+        {
+            LOG(WARNING) << item_type() << " unrecognized item type. Using byte.";
+        }
 
+    // the complex-ness of the input is inferred from the output type
+    if (sample_type_ == "real")
+        {
+            is_complex_t = false;
+        }
+    else if (sample_type_ == "iq")
+        {
+            is_complex_t = true;
+        }
+    else if (sample_type_ == "qi")
+        {
+            is_complex_t = true;
+            reverse_interleaving_ = true;
+        }
+    else
+        {
+            LOG(WARNING) << sample_type_ << " unrecognized sample type. Assuming: "
+                         << (is_complex_t ? (reverse_interleaving_ ? "qi" : "iq") : "real");
+        }
+
+
+    return std::make_tuple(item_size, is_complex_t);
+}
+
+// Each sample is 2 bits; if the item_type() is char, then the size is 8/2 = 4 packets per sample
+// If the item_type() is short, then the size is 16/2 = 8 packets per sample
+double TwoBitPackedFileSignalSource::packetsPerSample() const { return item_size() / 2.0; }
+gnss_shared_ptr<gr::block> TwoBitPackedFileSignalSource::source() const { return char_to_float_; }
+
+void TwoBitPackedFileSignalSource::create_file_source_hook()
+{
+    unpack_samples_ = make_unpack_2bit_samples(big_endian_bytes_, item_size(),
+        big_endian_items_, reverse_interleaving_);
+    DLOG(INFO) << "unpack_byte_2bit_samples(" << unpack_samples_->unique_id() << ")";
+
+    if (is_complex())
+        {
+            char_to_float_ = gr::blocks::interleaved_char_to_complex::make(false);
+            DLOG(INFO) << "interleaved_char_to_complex(" << char_to_float_->unique_id() << ")";
+        }
+    else
+        {
+            char_to_float_ = gr::blocks::char_to_float::make();
+            DLOG(INFO) << "char_to_float(" << char_to_float_->unique_id() << ")";
+        }
+}
+
+void TwoBitPackedFileSignalSource::pre_connect_hook(gr::top_block_sptr top_block)
+{
+    top_block->connect(file_source(), 0, unpack_samples_, 0);
     DLOG(INFO) << "connected file source to unpack samples";
-    right_block = char_to_float_;
+    top_block->connect(unpack_samples_, 0, char_to_float_, 0);
-    top_block->connect(left_block, 0, right_block, 0);
-    left_block = right_block;
     DLOG(INFO) << "connected unpack samples to char to float";
-
-    if (enable_throttle_control_)
-        {
-            right_block = throttle_;
-            top_block->connect(left_block, 0, right_block, 0);
-            left_block = right_block;
-            DLOG(INFO) << " connected to throttle";
-        }
-
-    top_block->connect(left_block, 0, valve_, 0);
-    DLOG(INFO) << "connected to valve";
-    if (dump_)
-        {
-            top_block->connect(valve_, 0, sink_, 0);
-            DLOG(INFO) << "connected valve to file sink";
-        }
 }
 
-
+void TwoBitPackedFileSignalSource::pre_disconnect_hook(gr::top_block_sptr top_block)
-void TwoBitPackedFileSignalSource::disconnect(gr::top_block_sptr top_block)
 {
-    gr::basic_block_sptr left_block = file_source_;
+    top_block->disconnect(file_source(), 0, unpack_samples_, 0);
-    gr::basic_block_sptr right_block = unpack_samples_;
-
-    top_block->disconnect(file_source_, 0, unpack_samples_, 0);
-    left_block = right_block;
-
     DLOG(INFO) << "disconnected file source to unpack samples";
-    right_block = char_to_float_;
+    top_block->disconnect(unpack_samples_, 0, char_to_float_, 0);
-    top_block->disconnect(left_block, 0, right_block, 0);
-    left_block = right_block;
     DLOG(INFO) << "disconnected unpack samples to char to float";
-
-    if (enable_throttle_control_)
-        {
-            right_block = throttle_;
-            top_block->disconnect(left_block, 0, right_block, 0);
-            left_block = right_block;
-            DLOG(INFO) << " disconnected to throttle";
-        }
-
-    top_block->disconnect(left_block, 0, valve_, 0);
-    DLOG(INFO) << "disconnected to valve";
-    if (dump_)
-        {
-            top_block->disconnect(valve_, 0, sink_, 0);
-            DLOG(INFO) << "disconnected valve to file sink";
-        }
-}
-
-
-gr::basic_block_sptr TwoBitPackedFileSignalSource::get_left_block()
-{
-    LOG(WARNING) << "Left block of a signal source should not be retrieved";
-    // return gr_block_sptr();
-    return gr::blocks::file_source::sptr();
-}
-
-
-gr::basic_block_sptr TwoBitPackedFileSignalSource::get_right_block()
-{
-    return valve_;
 }

src/algorithms/signal_source/adapters/two_bit_packed_file_signal_source.h

@@ -21,17 +21,9 @@
 #ifndef GNSS_SDR_TWO_BIT_PACKED_FILE_SIGNAL_SOURCE_H
 #define GNSS_SDR_TWO_BIT_PACKED_FILE_SIGNAL_SOURCE_H
 
-#include "concurrent_queue.h"
+#include "file_source_base.h"
-#include "gnss_block_interface.h"
 #include "unpack_2bit_samples.h"
-#include <gnuradio/blocks/file_sink.h>
-#include <gnuradio/blocks/file_source.h>
 #include <gnuradio/blocks/interleaved_char_to_complex.h>
-#include <gnuradio/blocks/throttle.h>
-#include <gnuradio/hier_block2.h>
-#include <pmt/pmt.h>
-#include <cstdint>
-#include <string>
 
 
 /** \addtogroup Signal_Source
@@ -46,7 +38,7 @@ class ConfigurationInterface;
  * \brief Class that reads signals samples from a file
  * and adapts it to a SignalSourceInterface
  */
-class TwoBitPackedFileSignalSource : public GNSSBlockInterface
+class TwoBitPackedFileSignalSource : public FileSourceBase
 {
 public:
     TwoBitPackedFileSignalSource(const ConfigurationInterface* configuration, const std::string& role,
@@ -54,54 +46,8 @@ public:
         Concurrent_Queue<pmt::pmt_t>* queue);
 
     ~TwoBitPackedFileSignalSource() = default;
-    inline std::string role() override
-    {
-        return role_;
-    }
-
-    /*!
-     * \brief Returns "Two_Bit_Packed_File_Signal_Source".
-     */
-    inline std::string implementation() override
-    {
-        return "Two_Bit_Packed_File_Signal_Source";
-    }
-
-    inline size_t item_size() override
-    {
-        return item_size_;
-    }
-
-    void connect(gr::top_block_sptr top_block) override;
-    void disconnect(gr::top_block_sptr top_block) override;
-    gr::basic_block_sptr get_left_block() override;
-    gr::basic_block_sptr get_right_block() override;
-
-    inline std::string filename() const
-    {
-        return filename_;
-    }
-
-    inline std::string item_type() const
-    {
-        return item_type_;
-    }
-
-    inline bool repeat() const
-    {
-        return repeat_;
-    }
-
-    inline int64_t sampling_frequency() const
-    {
-        return sampling_frequency_;
-    }
-
-    inline uint64_t samples() const
-    {
-        return samples_;
-    }
 
+private:
     inline bool big_endian_items() const
     {
         return big_endian_items_;
@@ -112,41 +58,27 @@ public:
         return big_endian_bytes_;
     }
 
-    inline bool is_complex() const
-    {
-        return is_complex_;
-    }
 
     inline bool reverse_interleaving() const
     {
         return reverse_interleaving_;
     }
 
+protected:
+    std::tuple<size_t, bool> itemTypeToSize() override;
+    double packetsPerSample() const override;
+    gnss_shared_ptr<gr::block> source() const override;
+    void create_file_source_hook() override;
+    void pre_connect_hook(gr::top_block_sptr top_block) override;
+    void pre_disconnect_hook(gr::top_block_sptr top_block) override;
+
 private:
-    gr::blocks::file_source::sptr file_source_;
-    unpack_2bit_samples_sptr unpack_samples_;
-    gr::basic_block_sptr char_to_float_;
-    gnss_shared_ptr<gr::block> valve_;
-    gr::blocks::file_sink::sptr sink_;
-    gr::blocks::throttle::sptr throttle_;
-    std::string filename_;
-    std::string item_type_;
-    std::string dump_filename_;
-    std::string role_;
     std::string sample_type_;
-    uint64_t samples_;
-    int64_t sampling_frequency_;
-    size_t item_size_;
-    unsigned int in_streams_;
-    unsigned int out_streams_;
     bool big_endian_items_;
     bool big_endian_bytes_;
-    bool is_complex_;
     bool reverse_interleaving_;
-    bool repeat_;
+    unpack_2bit_samples_sptr unpack_samples_;
-    bool dump_;
+    gnss_shared_ptr<gr::block> char_to_float_;
-    // Throttle control
-    bool enable_throttle_control_;
 };
 
 

src/algorithms/signal_source/adapters/uhd_signal_source.cc

@@ -17,6 +17,7 @@
 #include "uhd_signal_source.h"
 #include "GPS_L1_CA.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include "gnss_sdr_valve.h"
 #include <glog/logging.h>
 #include <uhd/exception.hpp>
@@ -25,10 +26,13 @@
 #include <iostream>
 #include <utility>
 
+using namespace std::string_literals;
+
 
 UhdSignalSource::UhdSignalSource(const ConfigurationInterface* configuration,
     const std::string& role, unsigned int in_stream, unsigned int out_stream,
-    Concurrent_Queue<pmt::pmt_t>* queue) : role_(role), in_stream_(in_stream), out_stream_(out_stream)
+    Concurrent_Queue<pmt::pmt_t>* queue)
+    : SignalSourceBase(configuration, role, "UHD_Signal_Source"s), in_stream_(in_stream), out_stream_(out_stream)
 {
     // DUMP PARAMETERS
     const std::string empty;

src/algorithms/signal_source/adapters/uhd_signal_source.h

@@ -18,7 +18,7 @@
 #define GNSS_SDR_UHD_SIGNAL_SOURCE_H
 
 #include "concurrent_queue.h"
-#include "gnss_block_interface.h"
+#include "signal_source_base.h"
 #include <gnuradio/blocks/file_sink.h>
 #include <gnuradio/hier_block2.h>
 #include <gnuradio/uhd/usrp_source.h>
@@ -38,7 +38,7 @@ class ConfigurationInterface;
 /*!
  * \brief This class reads samples from a UHD device (see http://code.ettus.com/redmine/ettus/projects/uhd/wiki)
  */
-class UhdSignalSource : public GNSSBlockInterface
+class UhdSignalSource : public SignalSourceBase
 {
 public:
     UhdSignalSource(const ConfigurationInterface* configuration,
@@ -47,19 +47,6 @@ public:
 
     ~UhdSignalSource() = default;
 
-    inline std::string role() override
-    {
-        return role_;
-    }
-
-    /*!
-     * \brief Returns "UHD_Signal_Source"
-     */
-    inline std::string implementation() override
-    {
-        return "UHD_Signal_Source";
-    }
-
     inline size_t item_size() override
     {
         return item_size_;
@@ -89,7 +76,6 @@ private:
     std::string item_type_;
     std::string subdevice_;
     std::string clock_source_;
-    std::string role_;
 
     double sample_rate_;
     size_t item_size_;

src/core/interfaces/signal_source_interface.h

@@ -0,0 +1,65 @@
+/*!
+ * \signal_source_interface.h
+ * \brief Header file of the interface to a signal_source GNSS block.
+ * \author Jim Melton, 2020. jim.melton(at)sncorp.com
+ *
+ * This header file contains the interface to an abstract class for
+ * signal sources. Since all its methods are virtual, this class
+ * cannot be instantiated directly, and a subclass can only be
+ * instantiated directly if all inherited pure virtual methods have
+ * been implemented by that class or a parent class.
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
+ *
+ * GNSS-SDR is a software defined Global Navigation
+ *          Satellite Systems receiver
+ *
+ * This file is part of GNSS-SDR.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * -----------------------------------------------------------------------------
+ */
+
+#ifndef GNSS_SDR_SIGNAL_SOURCE_INTERFACE_H
+#define GNSS_SDR_SIGNAL_SOURCE_INTERFACE_H
+
+#include "gnss_block_interface.h"
+#include <glog/logging.h>
+
+/** \addtogroup Core
+ * \{ */
+/** \addtogroup GNSS_Block_Interfaces GNSS block interfaces
+ * GNSS block interfaces.
+ * \{ */
+
+/*! \brief This abstract class represents an interface to signal_source GNSS block.
+ *
+ * Abstract class for signal sources. Since all its methods are virtual,
+ * this class cannot be instantiated directly, and a subclass can only be
+ * instantiated directly if all inherited pure virtual methods have been
+ * implemented by that class or a parent class.
+ */
+
+class SignalSourceInterface : public GNSSBlockInterface
+{
+public:
+    virtual size_t getRfChannels() const = 0;
+
+protected:
+    SignalSourceInterface()
+    {
+        VLOG(1) << "SignalSourceInterface: " << this << " ctor";
+    }
+
+public:  // required for polymorphic destruction
+    ~SignalSourceInterface()
+    {
+        VLOG(1) << "SignalSourceInterface: " << this << " dtor";
+    }
+};
+
+
+#endif

src/core/receiver/CMakeLists.txt

@@ -151,6 +151,7 @@ target_link_libraries(core_receiver
     PUBLIC
         core_libs
     PRIVATE
+        algorithms_libs
         core_monitor
         signal_source_adapters
         data_type_adapters
@@ -169,8 +170,6 @@ target_link_libraries(core_receiver
         Armadillo::armadillo
 )
 
-target_include_directories(core_receiver PRIVATE ${CMAKE_SOURCE_DIR}/src/algorithms/libs)
-
 if(ENABLE_ARMA_NO_DEBUG)
     target_compile_definitions(core_receiver
         PRIVATE -DARMA_NO_BOUND_CHECKING=1

src/core/receiver/gnss_block_factory.h

@@ -38,6 +38,7 @@
 
 class ConfigurationInterface;
 class GNSSBlockInterface;
+class SignalSourceInterface;
 class AcquisitionInterface;
 class TrackingInterface;
 class TelemetryDecoderInterface;
@@ -51,7 +52,7 @@ public:
     GNSSBlockFactory() = default;
     ~GNSSBlockFactory() = default;
 
-    std::unique_ptr<GNSSBlockInterface> GetSignalSource(const ConfigurationInterface* configuration,
+    std::unique_ptr<SignalSourceInterface> GetSignalSource(const ConfigurationInterface* configuration,
         Concurrent_Queue<pmt::pmt_t>* queue, int ID = -1);
 
     std::unique_ptr<GNSSBlockInterface> GetSignalConditioner(const ConfigurationInterface* configuration, int ID = -1);

src/core/receiver/gnss_flowgraph.cc

@@ -36,6 +36,7 @@
 #include "gnss_satellite.h"
 #include "gnss_sdr_make_unique.h"
 #include "gnss_synchro_monitor.h"
+#include "signal_source_interface.h"
 #include <boost/lexical_cast.hpp>    // for boost::lexical_cast
 #include <boost/tokenizer.hpp>       // for boost::tokenizer
 #include <glog/logging.h>            // for LOG
@@ -100,50 +101,19 @@ void GNSSFlowgraph::init()
     // 1. read the number of RF front-ends available (one file_source per RF front-end)
     sources_count_ = configuration_->property("Receiver.sources_count", 1);
 
-    int RF_Channels = 0;
     int signal_conditioner_ID = 0;
 
-    if (sources_count_ > 1)
+    for (int i = 0; i < sources_count_; i++)
         {
-            for (int i = 0; i < sources_count_; i++)
+            std::cout << "Creating source " << i << '\n';
+            sig_source_.push_back(block_factory->GetSignalSource(configuration_.get(), queue_.get(), i));
+            auto& src = sig_source_.back();
+            auto RF_Channels = src->getRfChannels();
+            std::cout << "RF Channels " << RF_Channels << '\n';
+            for (auto j = 0U; j < RF_Channels; ++j)
                 {
-                    std::cout << "Creating source " << i << '\n';
+                    sig_conditioner_.push_back(block_factory->GetSignalConditioner(configuration_.get(), signal_conditioner_ID));
-                    sig_source_.push_back(block_factory->GetSignalSource(configuration_.get(), queue_.get(), i));
+                    signal_conditioner_ID++;
-                    // TODO: Create a class interface for SignalSources, derived from GNSSBlockInterface.
-                    // Include GetRFChannels in the interface to avoid read config parameters here
-                    // read the number of RF channels for each front-end
-                    RF_Channels = configuration_->property(sig_source_.at(i)->role() + ".RF_channels", 1);
-                    std::cout << "RF Channels " << RF_Channels << '\n';
-                    for (int j = 0; j < RF_Channels; j++)
-                        {
-                            sig_conditioner_.push_back(block_factory->GetSignalConditioner(configuration_.get(), signal_conditioner_ID));
-                            signal_conditioner_ID++;
-                        }
-                }
-        }
-    else
-        {
-            // backwards compatibility for old config files
-            sig_source_.push_back(block_factory->GetSignalSource(configuration_.get(), queue_.get(), -1));
-            // TODO: Create a class interface for SignalSources, derived from GNSSBlockInterface.
-            // Include GetRFChannels in the interface to avoid read config parameters here
-            // read the number of RF channels for each front-end
-            if (sig_source_.at(0) != nullptr)
-                {
-                    RF_Channels = configuration_->property(sig_source_.at(0)->role() + ".RF_channels", 0);
-                }
-            if (RF_Channels != 0)
-                {
-                    for (int j = 0; j < RF_Channels; j++)
-                        {
-                            sig_conditioner_.push_back(block_factory->GetSignalConditioner(configuration_.get(), signal_conditioner_ID));
-                            signal_conditioner_ID++;
-                        }
-                }
-            else
-                {
-                    // old config file, single signal source and single channel, not specified
-                    sig_conditioner_.push_back(block_factory->GetSignalConditioner(configuration_.get(), -1));
                 }
         }
 
@@ -721,65 +691,66 @@ int GNSSFlowgraph::disconnect_signal_sources()
 
 int GNSSFlowgraph::connect_signal_conditioners()
 {
-    for (auto& sig : sig_conditioner_)
+    int error = 1;  // this should be bool (true)
+    try
         {
-            try
+            for (auto& sig : sig_conditioner_)
                 {
                     sig->connect(top_block_);
                 }
-            catch (const std::exception& e)
+            DLOG(INFO) << "Signal Conditioner blocks successfully connected to the top_block";
+            error = 0;  // false
+        }
+    catch (const std::exception& e)
+        {
+            LOG(ERROR) << "Can't connect signal conditioner block internally: " << e.what();
+            top_block_->disconnect_all();
+            std::string reported_error(e.what());
+            if (std::string::npos != reported_error.find(std::string("itemsize mismatch")))
+                {
+                    std::string replace_me("copy");
+                    size_t pos = reported_error.find(replace_me);
+                    while (pos != std::string::npos)
+                        {
+                            size_t len = replace_me.length();
+                            reported_error.replace(pos, len, "Pass_Through");
+                            pos = reported_error.find(replace_me, pos + 1);
+                        }
+                    help_hint_ += " * Blocks within the Signal Conditioner are connected with mismatched input/ouput item size\n";
+                    help_hint_ += "   Reported error: " + reported_error + '\n';
+                    help_hint_ += "   Check the Signal Conditioner documentation at https://gnss-sdr.org/docs/sp-blocks/signal-conditioner/\n";
+                }
+            if (std::string::npos != reported_error.find(std::string("DataTypeAdapter")))
+                {
+                    help_hint_ += " * The DataTypeAdapter implementation set in the configuration file does not exist\n";
+                    help_hint_ += "   Check the DataTypeAdapter documentation at https://gnss-sdr.org/docs/sp-blocks/data-type-adapter/\n";
+                }
+            if (std::string::npos != reported_error.find(std::string("InputFilter")))
                 {
-                    LOG(ERROR) << "Can't connect signal conditioner block internally: " << e.what();
-                    top_block_->disconnect_all();
-                    std::string reported_error(e.what());
                     if (std::string::npos != reported_error.find(std::string("itemsize mismatch")))
                         {
-                            std::string replace_me("copy");
+                            help_hint_ += " * The configured InputFilter input/output item types are not well defined.\n";
-                            size_t pos = reported_error.find(replace_me);
-                            while (pos != std::string::npos)
-                                {
-                                    size_t len = replace_me.length();
-                                    reported_error.replace(pos, len, "Pass_Through");
-                                    pos = reported_error.find(replace_me, pos + 1);
-                                }
-                            help_hint_ += " * Blocks within the Signal Conditioner are connected with mismatched input/ouput item size\n";
-                            help_hint_ += "   Reported error: " + reported_error + '\n';
-                            help_hint_ += "   Check the Signal Conditioner documentation at https://gnss-sdr.org/docs/sp-blocks/signal-conditioner/\n";
                         }
-                    if (std::string::npos != reported_error.find(std::string("DataTypeAdapter")))
+                    else
                         {
-                            help_hint_ += " * The DataTypeAdapter implementation set in the configuration file does not exist\n";
+                            help_hint_ += " * The InputFilter implementation set in the configuration file does not exist\n";
-                            help_hint_ += "   Check the DataTypeAdapter documentation at https://gnss-sdr.org/docs/sp-blocks/data-type-adapter/\n";
                         }
-                    if (std::string::npos != reported_error.find(std::string("InputFilter")))
+                    help_hint_ += "   Check the InputFilter documentation at https://gnss-sdr.org/docs/sp-blocks/input-filter/\n";
+                }
+            if (std::string::npos != reported_error.find(std::string("Resampler")))
+                {
+                    if (std::string::npos != reported_error.find(std::string("itemsize mismatch")))
                         {
-                            if (std::string::npos != reported_error.find(std::string("itemsize mismatch")))
+                            help_hint_ += " * The configured Resampler item type is not well defined.\n";
-                                {
-                                    help_hint_ += " * The configured InputFilter input/output item types are not well defined.\n";
-                                }
-                            else
-                                {
-                                    help_hint_ += " * The InputFilter implementation set in the configuration file does not exist\n";
-                                }
-                            help_hint_ += "   Check the InputFilter documentation at https://gnss-sdr.org/docs/sp-blocks/input-filter/\n";
                         }
-                    if (std::string::npos != reported_error.find(std::string("Resampler")))
+                    else
                         {
-                            if (std::string::npos != reported_error.find(std::string("itemsize mismatch")))
+                            help_hint_ += " * The Resampler implementation set in the configuration file does not exist\n";
-                                {
-                                    help_hint_ += " * The configured Resampler item type is not well defined.\n";
-                                }
-                            else
-                                {
-                                    help_hint_ += " * The Resampler implementation set in the configuration file does not exist\n";
-                                }
-                            help_hint_ += "   Check the Resampler documentation at https://gnss-sdr.org/docs/sp-blocks/resampler/\n";
                         }
-                    return 1;
+                    help_hint_ += "   Check the Resampler documentation at https://gnss-sdr.org/docs/sp-blocks/resampler/\n";
                 }
         }
-    DLOG(INFO) << "Signal Conditioner blocks successfully connected to the top_block";
+    return error;
-    return 0;
 }
 
 
@@ -1028,42 +999,40 @@ int GNSSFlowgraph::disconnect_fpga_sample_counter()
 
 int GNSSFlowgraph::connect_signal_sources_to_signal_conditioners()
 {
-    int RF_Channels = 0;
     unsigned int signal_conditioner_ID = 0;
     for (int i = 0; i < sources_count_; i++)
         {
             try
                 {
+                    auto& src = sig_source_.at(i);
+
                     // TODO: Remove this array implementation and create generic multistream connector
                     // (if a signal source has more than 1 stream, then connect it to the multistream signal conditioner)
-                    if (sig_source_.at(i)->implementation() == "Raw_Array_Signal_Source")
+                    if (src->implementation() == "Raw_Array_Signal_Source")
                         {
                             // Multichannel Array
                             std::cout << "ARRAY MODE\n";
                             for (int j = 0; j < GNSS_SDR_ARRAY_SIGNAL_CONDITIONER_CHANNELS; j++)
                                 {
                                     std::cout << "connecting ch " << j << '\n';
-                                    top_block_->connect(sig_source_.at(i)->get_right_block(), j, sig_conditioner_.at(i)->get_left_block(), j);
+                                    top_block_->connect(src->get_right_block(), j, sig_conditioner_.at(i)->get_left_block(), j);
                                 }
                         }
                     else
                         {
-                            // TODO: Create a class interface for SignalSources, derived from GNSSBlockInterface.
+                            auto RF_Channels = src->getRfChannels();
-                            // Include GetRFChannels in the interface to avoid read config parameters here
-                            // read the number of RF channels for each front-end
-                            RF_Channels = configuration_->property(sig_source_.at(i)->role() + ".RF_channels", 1);
 
-                            for (int j = 0; j < RF_Channels; j++)
+                            for (auto j = 0U; j < RF_Channels; ++j)
                                 {
                                     // Connect the multichannel signal source to multiple signal conditioners
                                     // GNURADIO max_streams=-1 means infinite ports!
-                                    size_t output_size = sig_source_.at(i)->item_size();
+                                    size_t output_size = src->item_size();
                                     size_t input_size = sig_conditioner_.at(signal_conditioner_ID)->get_left_block()->input_signature()->sizeof_stream_item(0);
                                     // Check configuration inconsistencies
                                     if (output_size != input_size)
                                         {
-                                            help_hint_ += " * The Signal Source implementation " + sig_source_.at(i)->implementation() + " has an output with a ";
+                                            help_hint_ += " * The Signal Source implementation " + src->implementation() + " has an output with a ";
-                                            help_hint_ += sig_source_.at(i)->role() + ".item_size of " + std::to_string(output_size);
+                                            help_hint_ += src->role() + ".item_size of " + std::to_string(output_size);
                                             help_hint_ += " bytes, but it is connected to the Signal Conditioner implementation ";
                                             help_hint_ += sig_conditioner_.at(signal_conditioner_ID)->implementation() + " with input item size of " + std::to_string(input_size) + " bytes.\n";
                                             help_hint_ += "   Output ports must be connected to input ports with the same item size.\n";
@@ -1071,12 +1040,12 @@ int GNSSFlowgraph::connect_signal_sources_to_signal_conditioners()
                                             return 1;
                                         }
 
-                                    if (sig_source_.at(i)->get_right_block()->output_signature()->max_streams() > 1 or sig_source_.at(i)->get_right_block()->output_signature()->max_streams() == -1)
+                                    if (src->get_right_block()->output_signature()->max_streams() > 1 or src->get_right_block()->output_signature()->max_streams() == -1)
                                         {
                                             if (sig_conditioner_.size() > signal_conditioner_ID)
                                                 {
-                                                    LOG(INFO) << "connecting sig_source_ " << i << " stream " << j << " to conditioner " << j;
+                                                    LOG(INFO) << "connecting sig_source_ " << i << " stream " << j << " to conditioner " << signal_conditioner_ID;
-                                                    top_block_->connect(sig_source_.at(i)->get_right_block(), j, sig_conditioner_.at(signal_conditioner_ID)->get_left_block(), 0);
+                                                    top_block_->connect(src->get_right_block(), j, sig_conditioner_.at(signal_conditioner_ID)->get_left_block(), 0);
                                                 }
                                         }
                                     else
@@ -1084,14 +1053,14 @@ int GNSSFlowgraph::connect_signal_sources_to_signal_conditioners()
                                             if (j == 0)
                                                 {
                                                     // RF_channel 0 backward compatibility with single channel sources
-                                                    LOG(INFO) << "connecting sig_source_ " << i << " stream " << 0 << " to conditioner " << j;
+                                                    LOG(INFO) << "connecting sig_source_ " << i << " stream " << 0 << " to conditioner " << signal_conditioner_ID;
-                                                    top_block_->connect(sig_source_.at(i)->get_right_block(), 0, sig_conditioner_.at(signal_conditioner_ID)->get_left_block(), 0);
+                                                    top_block_->connect(src->get_right_block(), 0, sig_conditioner_.at(signal_conditioner_ID)->get_left_block(), 0);
                                                 }
                                             else
                                                 {
                                                     // Multiple channel sources using multiple output blocks of single channel (requires RF_channel selector in call)
-                                                    LOG(INFO) << "connecting sig_source_ " << i << " stream " << j << " to conditioner " << j;
+                                                    LOG(INFO) << "connecting sig_source_ " << i << " stream " << j << " to conditioner " << signal_conditioner_ID;
-                                                    top_block_->connect(sig_source_.at(i)->get_right_block(j), 0, sig_conditioner_.at(signal_conditioner_ID)->get_left_block(), 0);
+                                                    top_block_->connect(src->get_right_block(j), 0, sig_conditioner_.at(signal_conditioner_ID)->get_left_block(), 0);
                                                 }
                                         }
                                     signal_conditioner_ID++;
@@ -1127,46 +1096,44 @@ int GNSSFlowgraph::connect_signal_sources_to_signal_conditioners()
 
 int GNSSFlowgraph::disconnect_signal_sources_from_signal_conditioners()
 {
-    int RF_Channels = 0;
     int signal_conditioner_ID = 0;
     for (int i = 0; i < sources_count_; i++)
         {
             try
                 {
+                    auto& src = sig_source_.at(i);
+
                     // TODO: Remove this array implementation and create generic multistream connector
                     // (if a signal source has more than 1 stream, then connect it to the multistream signal conditioner)
-                    if (sig_source_.at(i)->implementation() == "Raw_Array_Signal_Source")
+                    if (src->implementation() == "Raw_Array_Signal_Source")
                         {
                             // Multichannel Array
                             for (int j = 0; j < GNSS_SDR_ARRAY_SIGNAL_CONDITIONER_CHANNELS; j++)
                                 {
-                                    top_block_->disconnect(sig_source_.at(i)->get_right_block(), j, sig_conditioner_.at(i)->get_left_block(), j);
+                                    top_block_->disconnect(src->get_right_block(), j, sig_conditioner_.at(i)->get_left_block(), j);
                                 }
                         }
                     else
                         {
-                            // TODO: Create a class interface for SignalSources, derived from GNSSBlockInterface.
+                            auto RF_Channels = src->getRfChannels();
-                            // Include GetRFChannels in the interface to avoid read config parameters here
-                            // read the number of RF channels for each front-end
-                            RF_Channels = configuration_->property(sig_source_.at(i)->role() + ".RF_channels", 1);
 
-                            for (int j = 0; j < RF_Channels; j++)
+                            for (auto j = 0U; j < RF_Channels; ++j)
                                 {
-                                    if (sig_source_.at(i)->get_right_block()->output_signature()->max_streams() > 1 or sig_source_.at(i)->get_right_block()->output_signature()->max_streams() == -1)
+                                    if (src->get_right_block()->output_signature()->max_streams() > 1 or src->get_right_block()->output_signature()->max_streams() == -1)
                                         {
-                                            top_block_->disconnect(sig_source_.at(i)->get_right_block(), j, sig_conditioner_.at(signal_conditioner_ID)->get_left_block(), 0);
+                                            top_block_->disconnect(src->get_right_block(), j, sig_conditioner_.at(signal_conditioner_ID)->get_left_block(), 0);
                                         }
                                     else
                                         {
                                             if (j == 0)
                                                 {
                                                     // RF_channel 0 backward compatibility with single channel sources
-                                                    top_block_->disconnect(sig_source_.at(i)->get_right_block(), 0, sig_conditioner_.at(signal_conditioner_ID)->get_left_block(), 0);
+                                                    top_block_->disconnect(src->get_right_block(), 0, sig_conditioner_.at(signal_conditioner_ID)->get_left_block(), 0);
                                                 }
                                             else
                                                 {
                                                     // Multiple channel sources using multiple output blocks of single channel (requires RF_channel selector in call)
-                                                    top_block_->disconnect(sig_source_.at(i)->get_right_block(j), 0, sig_conditioner_.at(signal_conditioner_ID)->get_left_block(), 0);
+                                                    top_block_->disconnect(src->get_right_block(j), 0, sig_conditioner_.at(signal_conditioner_ID)->get_left_block(), 0);
                                                 }
                                         }
                                     signal_conditioner_ID++;

src/core/receiver/gnss_flowgraph.h

@@ -53,6 +53,7 @@ class ChannelInterface;
 class ConfigurationInterface;
 class GNSSBlockInterface;
 class Gnss_Satellite;
+class SignalSourceInterface;
 
 /*! \brief This class represents a GNSS flow graph.
  *
@@ -230,7 +231,7 @@ private:
     std::shared_ptr<ConfigurationInterface> configuration_;
     std::shared_ptr<Concurrent_Queue<pmt::pmt_t>> queue_;
 
-    std::vector<std::shared_ptr<GNSSBlockInterface>> sig_source_;
+    std::vector<std::shared_ptr<SignalSourceInterface>> sig_source_;
     std::vector<std::shared_ptr<GNSSBlockInterface>> sig_conditioner_;
     std::vector<std::shared_ptr<ChannelInterface>> channels_;
     std::shared_ptr<GNSSBlockInterface> observables_;

src/tests/unit-tests/control-plane/gnss_block_factory_test.cc

@@ -28,6 +28,7 @@
 #include "in_memory_configuration.h"
 #include "observables_interface.h"
 #include "pvt_interface.h"
+#include "signal_source_interface.h"
 #include "telemetry_decoder_interface.h"
 #include "tracking_interface.h"
 #include <gtest/gtest.h>
@@ -45,7 +46,7 @@ TEST(GNSSBlockFactoryTest, InstantiateFileSignalSource)
     // Example of a factory as a shared_ptr
     std::shared_ptr<GNSSBlockFactory> factory = std::make_shared<GNSSBlockFactory>();
     // Example of a block as a shared_ptr
-    std::shared_ptr<GNSSBlockInterface> signal_source = factory->GetSignalSource(configuration.get(), queue.get());
+    auto signal_source = factory->GetSignalSource(configuration.get(), queue.get());
     EXPECT_STREQ("SignalSource", signal_source->role().c_str());
     EXPECT_STREQ("File_Signal_Source", signal_source->implementation().c_str());
 }
@@ -59,7 +60,7 @@ TEST(GNSSBlockFactoryTest, InstantiateWrongSignalSource)
     // Example of a factory as a unique_ptr
     std::unique_ptr<GNSSBlockFactory> factory = std::make_unique<GNSSBlockFactory>();
     // Example of a block as a unique_ptr
-    std::unique_ptr<GNSSBlockInterface> signal_source = factory->GetSignalSource(configuration.get(), queue.get());
+    auto signal_source = factory->GetSignalSource(configuration.get(), queue.get());
     EXPECT_EQ(nullptr, signal_source);
 }
 
@@ -350,8 +351,8 @@ TEST(GNSSBlockFactoryTest, InstantiateWrongPvt)
 {
     std::shared_ptr<InMemoryConfiguration> configuration = std::make_shared<InMemoryConfiguration>();
     configuration->set_property("PVT.implementation", "Pepito");
-    std::unique_ptr<GNSSBlockFactory> factory = std::make_unique<GNSSBlockFactory>();
+    auto factory = std::make_unique<GNSSBlockFactory>();
     std::shared_ptr<GNSSBlockInterface> pvt_ = factory->GetPVT(configuration.get());
-    std::shared_ptr<PvtInterface> pvt = std::dynamic_pointer_cast<PvtInterface>(pvt_);
+    auto pvt = std::dynamic_pointer_cast<PvtInterface>(pvt_);
     EXPECT_EQ(nullptr, pvt);
 }

src/tests/unit-tests/signal-processing-blocks/sources/file_signal_source_test.cc

@@ -53,5 +53,9 @@ TEST(FileSignalSource, InstantiateFileNotExists)
     config->set_property("Test.item_type", "gr_complex");
     config->set_property("Test.repeat", "false");
 
-    EXPECT_THROW({ auto uptr = std::make_shared<FileSignalSource>(config.get(), "Test", 0, 1, queue.get()); }, std::exception);
+    // the file existence test was moved from the ctor to the connect() call. The argument to
+    // connect doesn't matter, since the exception should be thrown sooner than any connections
+    auto top = gr::make_top_block("GNSSUnitTest");
+    auto uptr = std::make_shared<FileSignalSource>(config.get(), "Test", 0, 1, queue.get());
+    EXPECT_THROW({ uptr->connect(top); }, std::exception);
 }

src/utils/front-end-cal/main.cc

@@ -36,7 +36,8 @@
 #include "gps_iono.h"
 #include "gps_l1_ca_pcps_acquisition_fine_doppler.h"
 #include "gps_utc_model.h"
-#include <boost/any.hpp>  // for bad_any_cast
+#include "signal_source_interface.h"  // for SignalSourceInterface
+#include <boost/any.hpp>              // for bad_any_cast
 #include <boost/exception/exception.hpp>
 #include <boost/lexical_cast.hpp>
 #include <gflags/gflags.h>
@@ -181,6 +182,10 @@ void wait_message()
 
 bool front_end_capture(const std::shared_ptr<ConfigurationInterface>& configuration)
 {
+    auto success = false;
+
+    std::string trace_step;
+
     gr::top_block_sptr top_block;
     GNSSBlockFactory block_factory;
     std::shared_ptr<Concurrent_Queue<pmt::pmt_t>> queue;
@@ -188,43 +193,37 @@ bool front_end_capture(const std::shared_ptr<ConfigurationInterface>& configurat
     queue = std::make_shared<Concurrent_Queue<pmt::pmt_t>>();
     top_block = gr::make_top_block("Acquisition test");
 
-    std::shared_ptr<GNSSBlockInterface> source;
     try
         {
+            // Note: the block_factory returns a unique_ptr (what you would get with an "auto"
+            // declaration), but the flowgraph uses shared_ptr. Without further understanding of why
+            // it should matter in this context, used shared_ptr throughout
+            std::shared_ptr<SignalSourceInterface> source;
+            std::shared_ptr<GNSSBlockInterface> conditioner;
+
+            trace_step = "creating source";
             source = block_factory.GetSignalSource(configuration.get(), queue.get());
-        }
-    catch (const boost::exception_ptr& e)
-        {
-            std::cout << "Exception caught in creating source " << e << '\n';
-            return false;
-        }
 
-    std::shared_ptr<GNSSBlockInterface> conditioner;
+            trace_step = "creating signal conditioner";
-    try
-        {
             conditioner = block_factory.GetSignalConditioner(configuration.get());
-        }
-    catch (const boost::exception_ptr& e)
-        {
-            std::cout << "Exception caught in creating signal conditioner " << e << '\n';
-            return false;
-        }
-    gr::block_sptr sink;
-    sink = gr::blocks::file_sink::make(sizeof(gr_complex), "tmp_capture.dat");
 
-    // -- Find number of samples per spreading code ---
+            trace_step = "unexpected in setup code";
-    int64_t fs_in_ = configuration->property("GNSS-SDR.internal_fs_sps", 2048000);
-    int samples_per_code = round(fs_in_ / (GPS_L1_CA_CODE_RATE_CPS / GPS_L1_CA_CODE_LENGTH_CHIPS));
-    int nsamples = samples_per_code * 50;
 
-    int skip_samples = fs_in_ * 5;  // skip 5 seconds
+            gr::block_sptr sink;
+            sink = gr::blocks::file_sink::make(sizeof(gr_complex), "tmp_capture.dat");
 
-    gr::block_sptr head = gr::blocks::head::make(sizeof(gr_complex), nsamples);
+            // -- Find number of samples per spreading code ---
+            int64_t fs_in_ = configuration->property("GNSS-SDR.internal_fs_sps", 2048000);
+            int samples_per_code = round(fs_in_ / (GPS_L1_CA_CODE_RATE_CPS / GPS_L1_CA_CODE_LENGTH_CHIPS));
+            int nsamples = samples_per_code * 50;
 
-    gr::block_sptr skiphead = gr::blocks::skiphead::make(sizeof(gr_complex), skip_samples);
+            int skip_samples = fs_in_ * 5;  // skip 5 seconds
 
-    try
+            gr::block_sptr head = gr::blocks::head::make(sizeof(gr_complex), nsamples);
-        {
+
+            gr::block_sptr skiphead = gr::blocks::skiphead::make(sizeof(gr_complex), skip_samples);
+
+            trace_step = "connecting the GNU Radio blocks";
             source->connect(top_block);
             conditioner->connect(top_block);
             top_block->connect(source->get_right_block(), 0, conditioner->get_left_block(), 0);
@@ -232,14 +231,15 @@ bool front_end_capture(const std::shared_ptr<ConfigurationInterface>& configurat
             top_block->connect(skiphead, 0, head, 0);
             top_block->connect(head, 0, sink, 0);
             top_block->run();
+
+            success = true;
         }
-    catch (const std::exception& e)
+    catch (std::exception const& e)
         {
-            std::cout << "Failure connecting the GNU Radio blocks " << e.what() << '\n';
+            std::cout << "Exception caught " << trace_step << ": " << e.what() << std::endl;
-            return false;
         }
 
-    return true;
+    return success;
 }