pv/session.cpp

/*
 * This file is part of the PulseView project.
 *
 * Copyright (C) 2012-14 Joel Holdsworth <joel@airwebreathe.org.uk>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include <cassert>
#include <memory>
#include <mutex>
#include <stdexcept>

#include <sys/stat.h>

#include <QDebug>
#include <QFileInfo>

#include "devicemanager.hpp"
#include "mainwindow.hpp"
#include "session.hpp"
#include "util.hpp"

#include "data/analog.hpp"
#include "data/analogsegment.hpp"
#include "data/decode/decoder.hpp"
#include "data/logic.hpp"
#include "data/logicsegment.hpp"
#include "data/signalbase.hpp"

#include "devices/hardwaredevice.hpp"
#include "devices/inputfile.hpp"
#include "devices/sessionfile.hpp"

#include "toolbars/mainbar.hpp"

#include "views/trace/analogsignal.hpp"
#include "views/trace/decodetrace.hpp"
#include "views/trace/logicsignal.hpp"
#include "views/trace/signal.hpp"
#include "views/trace/view.hpp"

#include <libsigrokcxx/libsigrokcxx.hpp>

#ifdef ENABLE_FLOW
#include <gstreamermm.h>
#include <libsigrokflow/libsigrokflow.hpp>
#endif

#ifdef ENABLE_DECODE
#include <libsigrokdecode/libsigrokdecode.h>
#include "data/decodesignal.hpp"
#endif

using std::bad_alloc;
using std::dynamic_pointer_cast;
using std::find_if;
using std::function;
using std::list;
using std::lock_guard;
using std::make_pair;
using std::make_shared;
using std::map;
using std::max;
using std::move;
using std::mutex;
using std::pair;
using std::recursive_mutex;
using std::runtime_error;
using std::shared_ptr;
using std::string;
#ifdef ENABLE_FLOW
using std::unique_lock;
#endif
using std::unique_ptr;
using std::vector;

using sigrok::Analog;
using sigrok::Channel;
using sigrok::ConfigKey;
using sigrok::DatafeedCallbackFunction;
using sigrok::Error;
using sigrok::InputFormat;
using sigrok::Logic;
using sigrok::Meta;
using sigrok::Packet;
using sigrok::Session;

using Glib::VariantBase;

#ifdef ENABLE_FLOW
using Gst::Bus;
using Gst::ElementFactory;
using Gst::Pipeline;
#endif

using pv::util::Timestamp;
using pv::views::trace::Signal;
using pv::views::trace::AnalogSignal;
using pv::views::trace::LogicSignal;

namespace pv {

shared_ptr<sigrok::Context> Session::sr_context;

Session::Session(DeviceManager &device_manager, QString name) :
	device_manager_(device_manager),
	default_name_(name),
	name_(name),
	capture_state_(Stopped),
	cur_samplerate_(0),
	data_saved_(true)
{
}

Session::~Session()
{
	// Stop and join to the thread
	stop_capture();
}

DeviceManager& Session::device_manager()
{
	return device_manager_;
}

const DeviceManager& Session::device_manager() const
{
	return device_manager_;
}

shared_ptr<sigrok::Session> Session::session() const
{
	if (!device_)
		return shared_ptr<sigrok::Session>();
	return device_->session();
}

shared_ptr<devices::Device> Session::device() const
{
	return device_;
}

QString Session::name() const
{
	return name_;
}

void Session::set_name(QString name)
{
	if (default_name_.isEmpty())
		default_name_ = name;

	name_ = name;

	name_changed();
}

const vector< shared_ptr<views::ViewBase> > Session::views() const
{
	return views_;
}

shared_ptr<views::ViewBase> Session::main_view() const
{
	return main_view_;
}

void Session::set_main_bar(shared_ptr<pv::toolbars::MainBar> main_bar)
{
	main_bar_ = main_bar;
}

shared_ptr<pv::toolbars::MainBar> Session::main_bar() const
{
	return main_bar_;
}

bool Session::data_saved() const
{
	return data_saved_;
}

void Session::save_setup(QSettings &settings) const
{
	int i = 0;

	// Save channels and decoders
	for (const shared_ptr<data::SignalBase>& base : signalbases_) {
#ifdef ENABLE_DECODE
		if (base->is_decode_signal()) {
			settings.beginGroup("decode_signal" + QString::number(i++));
			base->save_settings(settings);
			settings.endGroup();
		} else
#endif
		{
			settings.beginGroup(base->internal_name());
			base->save_settings(settings);
			settings.endGroup();
		}
	}

	settings.setValue("decode_signals", i);

	// Save view states and their signal settings
	// Note: main_view must be saved as view0
	i = 0;
	settings.beginGroup("view" + QString::number(i++));
	main_view_->save_settings(settings);
	settings.endGroup();

	for (const shared_ptr<views::ViewBase>& view : views_) {
		if (view != main_view_) {
			settings.beginGroup("view" + QString::number(i++));
			settings.setValue("type", view->get_type());
			view->save_settings(settings);
			settings.endGroup();
		}
	}

	settings.setValue("views", i);

	int view_id = 0;
	i = 0;
	for (const shared_ptr<views::ViewBase>& vb : views_) {
		shared_ptr<views::trace::View> tv = dynamic_pointer_cast<views::trace::View>(vb);
		if (tv) {
			for (const shared_ptr<views::trace::TimeItem>& time_item : tv->time_items()) {

				const shared_ptr<views::trace::Flag> flag =
					dynamic_pointer_cast<views::trace::Flag>(time_item);
				if (flag) {
					if (!flag->enabled())
						continue;

					settings.beginGroup("meta_obj" + QString::number(i++));
					settings.setValue("type", "time_marker");
					settings.setValue("assoc_view", view_id);
					GlobalSettings::store_timestamp(settings, "time", flag->time());
					settings.setValue("text", flag->get_text());
					settings.endGroup();
				}
			}

			if (tv->cursors_shown()) {
				settings.beginGroup("meta_obj" + QString::number(i++));
				settings.setValue("type", "selection");
				settings.setValue("assoc_view", view_id);
				const shared_ptr<views::trace::CursorPair> cp = tv->cursors();
				GlobalSettings::store_timestamp(settings, "start_time", cp->first()->time());
				GlobalSettings::store_timestamp(settings, "end_time", cp->second()->time());
				settings.endGroup();
			}
		}

		view_id++;
	}

	settings.setValue("meta_objs", i);
}

void Session::save_settings(QSettings &settings) const
{
	map<string, string> dev_info;
	list<string> key_list;

	if (device_) {
		shared_ptr<devices::HardwareDevice> hw_device =
			dynamic_pointer_cast< devices::HardwareDevice >(device_);

		if (hw_device) {
			settings.setValue("device_type", "hardware");
			settings.beginGroup("device");

			key_list.emplace_back("vendor");
			key_list.emplace_back("model");
			key_list.emplace_back("version");
			key_list.emplace_back("serial_num");
			key_list.emplace_back("connection_id");

			dev_info = device_manager_.get_device_info(device_);

			for (string& key : key_list) {
				if (dev_info.count(key))
					settings.setValue(QString::fromUtf8(key.c_str()),
							QString::fromUtf8(dev_info.at(key).c_str()));
				else
					settings.remove(QString::fromUtf8(key.c_str()));
			}

			settings.endGroup();
		}

		shared_ptr<devices::SessionFile> sessionfile_device =
			dynamic_pointer_cast<devices::SessionFile>(device_);

		if (sessionfile_device) {
			settings.setValue("device_type", "sessionfile");
			settings.beginGroup("device");
			settings.setValue("filename", QString::fromStdString(
				sessionfile_device->full_name()));
			settings.endGroup();
		}

		shared_ptr<devices::InputFile> inputfile_device =
			dynamic_pointer_cast<devices::InputFile>(device_);

		if (inputfile_device) {
			settings.setValue("device_type", "inputfile");
			settings.beginGroup("device");
			inputfile_device->save_meta_to_settings(settings);
			settings.endGroup();
		}

		save_setup(settings);
	}
}

void Session::restore_setup(QSettings &settings)
{
	// Restore channels
	for (shared_ptr<data::SignalBase> base : signalbases_) {
		settings.beginGroup(base->internal_name());
		base->restore_settings(settings);
		settings.endGroup();
	}

	// Restore decoders
#ifdef ENABLE_DECODE
	int decode_signals = settings.value("decode_signals").toInt();

	for (int i = 0; i < decode_signals; i++) {
		settings.beginGroup("decode_signal" + QString::number(i));
		shared_ptr<data::DecodeSignal> signal = add_decode_signal();
		signal->restore_settings(settings);
		settings.endGroup();
	}
#endif

	// Restore views
	int views = settings.value("views").toInt();

	for (int i = 0; i < views; i++) {
		settings.beginGroup("view" + QString::number(i));

		if (i > 0) {
			views::ViewType type = (views::ViewType)settings.value("type").toInt();
			add_view(type, this);
			views_.back()->restore_settings(settings);
		} else
			main_view_->restore_settings(settings);

		settings.endGroup();
	}

	// Restore meta objects like markers and cursors
	int meta_objs = settings.value("meta_objs").toInt();

	for (int i = 0; i < meta_objs; i++) {
		settings.beginGroup("meta_obj" + QString::number(i));

		shared_ptr<views::ViewBase> vb;
		shared_ptr<views::trace::View> tv;
		if (settings.contains("assoc_view"))
			vb = views_.at(settings.value("assoc_view").toInt());

		if (vb)
			tv = dynamic_pointer_cast<views::trace::View>(vb);

		const QString type = settings.value("type").toString();

		if ((type == "time_marker") && tv) {
			Timestamp ts = GlobalSettings::restore_timestamp(settings, "time");
			shared_ptr<views::trace::Flag> flag = tv->add_flag(ts);
			flag->set_text(settings.value("text").toString());
		}

		if ((type == "selection") && tv) {
			Timestamp start = GlobalSettings::restore_timestamp(settings, "start_time");
			Timestamp end = GlobalSettings::restore_timestamp(settings, "end_time");
			tv->set_cursors(start, end);
			tv->show_cursors();
		}

		settings.endGroup();
	}
}

void Session::restore_settings(QSettings &settings)
{
	shared_ptr<devices::Device> device;

	const QString device_type = settings.value("device_type").toString();

	if (device_type == "hardware") {
		map<string, string> dev_info;
		list<string> key_list;

		// Re-select last used device if possible but only if it's not demo
		settings.beginGroup("device");
		key_list.emplace_back("vendor");
		key_list.emplace_back("model");
		key_list.emplace_back("version");
		key_list.emplace_back("serial_num");
		key_list.emplace_back("connection_id");

		for (string key : key_list) {
			const QString k = QString::fromStdString(key);
			if (!settings.contains(k))
				continue;

			const string value = settings.value(k).toString().toStdString();
			if (!value.empty())
				dev_info.insert(make_pair(key, value));
		}

		if (dev_info.count("model") > 0)
			device = device_manager_.find_device_from_info(dev_info);

		if (device)
			set_device(device);

		settings.endGroup();
	}

	if ((device_type == "sessionfile") || (device_type == "inputfile")) {
		if (device_type == "sessionfile") {
			settings.beginGroup("device");
			const QString filename = settings.value("filename").toString();
			settings.endGroup();

			if (QFileInfo(filename).isReadable()) {
				device = make_shared<devices::SessionFile>(device_manager_.context(),
					filename.toStdString());
			}
		}

		if (device_type == "inputfile") {
			settings.beginGroup("device");
			device = make_shared<devices::InputFile>(device_manager_.context(),
				settings);
			settings.endGroup();
		}

		if (device) {
			set_device(device);

			start_capture([](QString infoMessage) {
				// TODO Emulate noquote()
				qDebug() << "Session error:" << infoMessage; });

			set_name(QString::fromStdString(
				dynamic_pointer_cast<devices::File>(device)->display_name(device_manager_)));
		}
	}

	if (device)
		restore_setup(settings);
}

void Session::select_device(shared_ptr<devices::Device> device)
{
	try {
		if (device)
			set_device(device);
		else
			set_default_device();
	} catch (const QString &e) {
		MainWindow::show_session_error(tr("Failed to select device"), e);
	}
}

void Session::set_device(shared_ptr<devices::Device> device)
{
	assert(device);

	// Ensure we are not capturing before setting the device
	stop_capture();

	if (device_)
		device_->close();

	device_.reset();

	// Revert name back to default name (e.g. "Session 1") as the data is gone
	name_ = default_name_;
	name_changed();

	// Remove all stored data and reset all views
	for (shared_ptr<views::ViewBase> view : views_) {
		view->clear_signals();
#ifdef ENABLE_DECODE
		view->clear_decode_signals();
#endif
		view->reset_view_state();
	}
	for (const shared_ptr<data::SignalData>& d : all_signal_data_)
		d->clear();
	all_signal_data_.clear();
	signalbases_.clear();
	cur_logic_segment_.reset();

	for (auto& entry : cur_analog_segments_) {
		shared_ptr<sigrok::Channel>(entry.first).reset();
		shared_ptr<data::AnalogSegment>(entry.second).reset();
	}

	logic_data_.reset();

	signals_changed();

	device_ = move(device);

	try {
		device_->open();
	} catch (const QString &e) {
		device_.reset();
		MainWindow::show_session_error(tr("Failed to open device"), e);
	}

	if (device_) {
		device_->session()->add_datafeed_callback([=]
			(shared_ptr<sigrok::Device> device, shared_ptr<Packet> packet) {
				data_feed_in(device, packet);
			});

		update_signals();
	}

	device_changed();
}

void Session::set_default_device()
{
	const list< shared_ptr<devices::HardwareDevice> > &devices =
		device_manager_.devices();

	if (devices.empty())
		return;

	// Try and find the demo device and select that by default
	const auto iter = find_if(devices.begin(), devices.end(),
		[] (const shared_ptr<devices::HardwareDevice> &d) {
			return d->hardware_device()->driver()->name() == "demo"; });
	set_device((iter == devices.end()) ? devices.front() : *iter);
}

bool Session::using_file_device() const
{
	shared_ptr<devices::SessionFile> sessionfile_device =
		dynamic_pointer_cast<devices::SessionFile>(device_);

	shared_ptr<devices::InputFile> inputfile_device =
		dynamic_pointer_cast<devices::InputFile>(device_);

	return (sessionfile_device || inputfile_device);
}

/**
 * Convert generic options to data types that are specific to InputFormat.
 *
 * @param[in] user_spec Vector of tokenized words, string format.
 * @param[in] fmt_opts Input format's options, result of InputFormat::options().
 *
 * @return Map of options suitable for InputFormat::create_input().
 */
map<string, Glib::VariantBase>
Session::input_format_options(vector<string> user_spec,
		map<string, shared_ptr<Option>> fmt_opts)
{
	map<string, Glib::VariantBase> result;

	for (auto& entry : user_spec) {
		/*
		 * Split key=value specs. Accept entries without separator
		 * (for simplified boolean specifications).
		 */
		string key, val;
		size_t pos = entry.find("=");
		if (pos == std::string::npos) {
			key = entry;
			val = "";
		} else {
			key = entry.substr(0, pos);
			val = entry.substr(pos + 1);
		}

		/*
		 * Skip user specifications that are not a member of the
		 * format's set of supported options. Have the text input
		 * spec converted to the required input format specific
		 * data type.
		 */
		auto found = fmt_opts.find(key);
		if (found == fmt_opts.end())
			continue;
		shared_ptr<Option> opt = found->second;
		result[key] = opt->parse_string(val);
	}

	return result;
}

void Session::load_init_file(const string &file_name,
	const string &format, const string &setup_file_name)
{
	shared_ptr<InputFormat> input_format;
	map<string, Glib::VariantBase> input_opts;

	if (!format.empty()) {
		const map<string, shared_ptr<InputFormat> > formats =
			device_manager_.context()->input_formats();
		auto user_opts = pv::util::split_string(format, ":");
		string user_name = user_opts.front();
		user_opts.erase(user_opts.begin());
		const auto iter = find_if(formats.begin(), formats.end(),
			[&](const pair<string, shared_ptr<InputFormat> > f) {
				return f.first == user_name; });
		if (iter == formats.end()) {
			MainWindow::show_session_error(tr("Error"),
				tr("Unexpected input format: %s").arg(QString::fromStdString(format)));
			return;
		}
		input_format = (*iter).second;
		input_opts = input_format_options(user_opts,
			input_format->options());
	}

	load_file(QString::fromStdString(file_name), QString::fromStdString(setup_file_name),
		input_format, input_opts);
}

void Session::load_file(QString file_name, QString setup_file_name,
	shared_ptr<sigrok::InputFormat> format, const map<string, Glib::VariantBase> &options)
{
	const QString errorMessage(
		QString("Failed to load file %1").arg(file_name));

	// In the absence of a caller's format spec, try to auto detect.
	// Assume "sigrok session file" upon lookup miss.
	if (!format)
		format = device_manager_.context()->input_format_match(file_name.toStdString());
	try {
		if (format)
			set_device(shared_ptr<devices::Device>(
				new devices::InputFile(
					device_manager_.context(),
					file_name.toStdString(),
					format, options)));
		else
			set_device(shared_ptr<devices::Device>(
				new devices::SessionFile(
					device_manager_.context(),
					file_name.toStdString())));
	} catch (Error& e) {
		MainWindow::show_session_error(tr("Failed to load %1").arg(file_name), e.what());
		set_default_device();
		main_bar_->update_device_list();
		return;
	}

	// Use the input file with .pvs extension if no setup file was given
	if (setup_file_name.isEmpty()) {
		setup_file_name = file_name;
		setup_file_name.truncate(setup_file_name.lastIndexOf('.'));
		setup_file_name.append(".pvs");
	}

	if (QFileInfo::exists(setup_file_name) && QFileInfo(setup_file_name).isReadable()) {
		QSettings settings_storage(setup_file_name, QSettings::IniFormat);
		restore_setup(settings_storage);
	}

	main_bar_->update_device_list();

	start_capture([&, errorMessage](QString infoMessage) {
		MainWindow::show_session_error(errorMessage, infoMessage); });

	set_name(QFileInfo(file_name).fileName());
}

Session::capture_state Session::get_capture_state() const
{
	lock_guard<mutex> lock(sampling_mutex_);
	return capture_state_;
}

void Session::start_capture(function<void (const QString)> error_handler)
{
	if (!device_) {
		error_handler(tr("No active device set, can't start acquisition."));
		return;
	}

	stop_capture();

	// Check that at least one channel is enabled
	const shared_ptr<sigrok::Device> sr_dev = device_->device();
	if (sr_dev) {
		const auto channels = sr_dev->channels();
		if (!any_of(channels.begin(), channels.end(),
			[](shared_ptr<Channel> channel) {
				return channel->enabled(); })) {
			error_handler(tr("No channels enabled."));
			return;
		}
	}

	// Clear signal data
	for (const shared_ptr<data::SignalData>& d : all_signal_data_)
		d->clear();

	trigger_list_.clear();

	// Revert name back to default name (e.g. "Session 1") for real devices
	// as the (possibly saved) data is gone. File devices keep their name.
	shared_ptr<devices::HardwareDevice> hw_device =
		dynamic_pointer_cast< devices::HardwareDevice >(device_);

	if (hw_device) {
		name_ = default_name_;
		name_changed();
	}

	// Begin the session
	sampling_thread_ = std::thread(
		&Session::sample_thread_proc, this, error_handler);
}

void Session::stop_capture()
{
	if (get_capture_state() != Stopped)
		device_->stop();

	// Check that sampling stopped
	if (sampling_thread_.joinable())
		sampling_thread_.join();
}

void Session::register_view(shared_ptr<views::ViewBase> view)
{
	if (views_.empty())
		main_view_ = view;

	views_.push_back(view);

	// Add all device signals
	update_signals();

	// Add all other signals
	vector< shared_ptr<data::SignalBase> > view_signalbases = view->signalbases();

	for (const shared_ptr<data::SignalBase>& signalbase : signalbases_) {
		const int sb_exists = count_if(
			view_signalbases.cbegin(), view_signalbases.cend(),
			[&](const shared_ptr<data::SignalBase> &sb) {
				return sb == signalbase;
			});

		// Add the signal to the view if it doesn't have it yet
		if (!sb_exists)
			switch (signalbase->type()) {
			case data::SignalBase::AnalogChannel:
			case data::SignalBase::LogicChannel:
			case data::SignalBase::MathChannel:
				view->add_signalbase(signalbase);
				break;
			case data::SignalBase::DecodeChannel:
#ifdef ENABLE_DECODE
				view->add_decode_signal(dynamic_pointer_cast<data::DecodeSignal>(signalbase));
#endif
				break;
			}
	}

	signals_changed();
}

void Session::deregister_view(shared_ptr<views::ViewBase> view)
{
	views_.erase(std::remove_if(views_.begin(), views_.end(),
		[&](shared_ptr<views::ViewBase> v) { return v == view; }),
		views_.end());

	if (views_.empty()) {
		main_view_.reset();

		// Without a view there can be no main bar
		main_bar_.reset();
	}
}

bool Session::has_view(shared_ptr<views::ViewBase> view)
{
	for (shared_ptr<views::ViewBase>& v : views_)
		if (v == view)
			return true;

	return false;
}

double Session::get_samplerate() const
{
	double samplerate = 0.0;

	for (const shared_ptr<pv::data::SignalData>& d : all_signal_data_) {
		assert(d);
		const vector< shared_ptr<pv::data::Segment> > segments =
			d->segments();
		for (const shared_ptr<pv::data::Segment>& s : segments)
			samplerate = max(samplerate, s->samplerate());
	}
	// If there is no sample rate given we use samples as unit
	if (samplerate == 0.0)
		samplerate = 1.0;

	return samplerate;
}

uint32_t Session::get_segment_count() const
{
	uint32_t value = 0;

	// Find the highest number of segments
	for (const shared_ptr<data::SignalData>& data : all_signal_data_)
		if (data->get_segment_count() > value)
			value = data->get_segment_count();

	return value;
}

vector<util::Timestamp> Session::get_triggers(uint32_t segment_id) const
{
	vector<util::Timestamp> result;

	for (const pair<uint32_t, util::Timestamp>& entry : trigger_list_)
		if (entry.first == segment_id)
			result.push_back(entry.second);

	return result;
}

const vector< shared_ptr<data::SignalBase> > Session::signalbases() const
{
	return signalbases_;
}

bool Session::all_segments_complete(uint32_t segment_id) const
{
	bool all_complete = true;

	for (const shared_ptr<data::SignalBase>& base : signalbases_)
		if (!base->segment_is_complete(segment_id))
			all_complete = false;

	return all_complete;
}

#ifdef ENABLE_DECODE
shared_ptr<data::DecodeSignal> Session::add_decode_signal()
{
	shared_ptr<data::DecodeSignal> signal;

	try {
		// Create the decode signal
		signal = make_shared<data::DecodeSignal>(*this);

		signalbases_.push_back(signal);

		// Add the decode signal to all views
		for (shared_ptr<views::ViewBase>& view : views_)
			view->add_decode_signal(signal);
	} catch (runtime_error& e) {
		remove_decode_signal(signal);
		return nullptr;
	}

	signals_changed();

	return signal;
}

void Session::remove_decode_signal(shared_ptr<data::DecodeSignal> signal)
{
	signalbases_.erase(std::remove_if(signalbases_.begin(), signalbases_.end(),
		[&](shared_ptr<data::SignalBase> s) { return s == signal; }),
		signalbases_.end());

	for (shared_ptr<views::ViewBase>& view : views_)
		view->remove_decode_signal(signal);

	signals_changed();
}
#endif

void Session::set_capture_state(capture_state state)
{
	bool changed;

	if (state == Running)
		acq_time_.restart();
	if (state == Stopped)
		qDebug("Acquisition took %.2f s", acq_time_.elapsed() / 1000.);

	{
		lock_guard<mutex> lock(sampling_mutex_);
		changed = capture_state_ != state;
		capture_state_ = state;
	}

	if (changed)
		capture_state_changed(state);
}

void Session::update_signals()
{
	if (!device_) {
		signalbases_.clear();
		logic_data_.reset();
		for (shared_ptr<views::ViewBase>& view : views_) {
			view->clear_signals();
#ifdef ENABLE_DECODE
			view->clear_decode_signals();
#endif
		}
		return;
	}

	lock_guard<recursive_mutex> lock(data_mutex_);

	const shared_ptr<sigrok::Device> sr_dev = device_->device();
	if (!sr_dev) {
		signalbases_.clear();
		logic_data_.reset();
		for (shared_ptr<views::ViewBase>& view : views_) {
			view->clear_signals();
#ifdef ENABLE_DECODE
			view->clear_decode_signals();
#endif
		}
		return;
	}

	// Detect what data types we will receive
	auto channels = sr_dev->channels();
	unsigned int logic_channel_count = count_if(
		channels.begin(), channels.end(),
		[] (shared_ptr<Channel> channel) {
			return channel->type() == sigrok::ChannelType::LOGIC; });

	// Create data containers for the logic data segments
	{
		lock_guard<recursive_mutex> data_lock(data_mutex_);

		if (logic_channel_count == 0) {
			logic_data_.reset();
		} else if (!logic_data_ ||
			logic_data_->num_channels() != logic_channel_count) {
			logic_data_.reset(new data::Logic(
				logic_channel_count));
			assert(logic_data_);
		}
	}

	// Make the signals list
	for (shared_ptr<views::ViewBase>& viewbase : views_) {
		views::trace::View *trace_view =
			qobject_cast<views::trace::View*>(viewbase.get());

		if (trace_view) {
			vector< shared_ptr<Signal> > prev_sigs(trace_view->signals());
			trace_view->clear_signals();

			for (auto channel : sr_dev->channels()) {
				shared_ptr<data::SignalBase> signalbase;
				shared_ptr<Signal> signal;

				// Find the channel in the old signals
				const auto iter = find_if(
					prev_sigs.cbegin(), prev_sigs.cend(),
					[&](const shared_ptr<Signal> &s) {
						return s->base()->channel() == channel;
					});
				if (iter != prev_sigs.end()) {
					// Copy the signal from the old set to the new
					signal = *iter;
					trace_view->add_signal(signal);
				} else {
					// Find the signalbase for this channel if possible
					signalbase.reset();
					for (const shared_ptr<data::SignalBase>& b : signalbases_)
						if (b->channel() == channel)
							signalbase = b;

					shared_ptr<Signal> signal;

					switch(channel->type()->id()) {
					case SR_CHANNEL_LOGIC:
						if (!signalbase) {
							signalbase = make_shared<data::SignalBase>(channel,
								data::SignalBase::LogicChannel);
							signalbases_.push_back(signalbase);

							all_signal_data_.insert(logic_data_);
							signalbase->set_data(logic_data_);

							connect(this, SIGNAL(capture_state_changed(int)),
								signalbase.get(), SLOT(on_capture_state_changed(int)));
						}

						signal = shared_ptr<Signal>(new LogicSignal(*this, device_, signalbase));
						break;

					case SR_CHANNEL_ANALOG:
					{
						if (!signalbase) {
							signalbase = make_shared<data::SignalBase>(channel,
								data::SignalBase::AnalogChannel);
							signalbases_.push_back(signalbase);

							shared_ptr<data::Analog> data(new data::Analog());
							all_signal_data_.insert(data);
							signalbase->set_data(data);

							connect(this, SIGNAL(capture_state_changed(int)),
								signalbase.get(), SLOT(on_capture_state_changed(int)));
						}

						signal = shared_ptr<Signal>(new AnalogSignal(*this, signalbase));
						break;
					}

					default:
						assert(false);
						break;
					}

					// New views take their signal settings from the main view
					if (!viewbase->is_main_view()) {
						shared_ptr<pv::views::trace::View> main_tv =
							dynamic_pointer_cast<pv::views::trace::View>(main_view_);
						shared_ptr<Signal> main_signal =
							main_tv->get_signal_by_signalbase(signalbase);
						signal->restore_settings(main_signal->save_settings());
					}

					trace_view->add_signal(signal);
				}
			}
		}
	}

	signals_changed();
}

shared_ptr<data::SignalBase> Session::signalbase_from_channel(
	shared_ptr<sigrok::Channel> channel) const
{
	for (shared_ptr<data::SignalBase> sig : signalbases_) {
		assert(sig);
		if (sig->channel() == channel)
			return sig;
	}
	return shared_ptr<data::SignalBase>();
}

void Session::sample_thread_proc(function<void (const QString)> error_handler)
{
	assert(error_handler);

#ifdef ENABLE_FLOW
	pipeline_ = Pipeline::create();

	source_ = ElementFactory::create_element("filesrc", "source");
	sink_ = RefPtr<AppSink>::cast_dynamic(ElementFactory::create_element("appsink", "sink"));

	pipeline_->add(source_)->add(sink_);
	source_->link(sink_);

	source_->set_property("location", Glib::ustring("/tmp/dummy_binary"));

	sink_->set_property("emit-signals", TRUE);
	sink_->signal_new_sample().connect(sigc::mem_fun(*this, &Session::on_gst_new_sample));

	// Get the bus from the pipeline and add a bus watch to the default main context
	RefPtr<Bus> bus = pipeline_->get_bus();
	bus->add_watch(sigc::mem_fun(this, &Session::on_gst_bus_message));

	// Start pipeline and Wait until it finished processing
	pipeline_done_interrupt_ = false;
	pipeline_->set_state(Gst::STATE_PLAYING);

	unique_lock<mutex> pipeline_done_lock_(pipeline_done_mutex_);
	pipeline_done_cond_.wait(pipeline_done_lock_);

	// Let the pipeline free all resources
	pipeline_->set_state(Gst::STATE_NULL);

#else
	if (!device_)
		return;

	try {
		cur_samplerate_ = device_->read_config<uint64_t>(ConfigKey::SAMPLERATE);
	} catch (Error& e) {
		cur_samplerate_ = 0;
	}

	out_of_memory_ = false;

	{
		lock_guard<recursive_mutex> lock(data_mutex_);
		cur_logic_segment_.reset();
		cur_analog_segments_.clear();
	}
	highest_segment_id_ = -1;
	frame_began_ = false;

	try {
		device_->start();
	} catch (Error& e) {
		error_handler(e.what());
		return;
	}

	set_capture_state(device_->session()->trigger() ?
		AwaitingTrigger : Running);

	try {
		device_->run();
	} catch (Error& e) {
		error_handler(e.what());
		set_capture_state(Stopped);
		return;
	} catch (QString& e) {
		error_handler(e);
		set_capture_state(Stopped);
		return;
	}

	set_capture_state(Stopped);

	// Confirm that SR_DF_END was received
	if (cur_logic_segment_)
		qDebug() << "WARNING: SR_DF_END was not received.";
#endif

	// Optimize memory usage
	free_unused_memory();

	// We now have unsaved data unless we just "captured" from a file
	shared_ptr<devices::File> file_device =
		dynamic_pointer_cast<devices::File>(device_);

	if (!file_device)
		data_saved_ = false;

	if (out_of_memory_)
		error_handler(tr("Out of memory, acquisition stopped."));
}

void Session::free_unused_memory()
{
	for (const shared_ptr<data::SignalData>& data : all_signal_data_) {
		const vector< shared_ptr<data::Segment> > segments = data->segments();

		for (const shared_ptr<data::Segment>& segment : segments)
			segment->free_unused_memory();
	}
}

void Session::signal_new_segment()
{
	int new_segment_id = 0;

	if ((cur_logic_segment_ != nullptr) || !cur_analog_segments_.empty()) {

		// Determine new frame/segment number, assuming that all
		// signals have the same number of frames/segments
		if (cur_logic_segment_) {
			new_segment_id = logic_data_->get_segment_count() - 1;
		} else {
			shared_ptr<sigrok::Channel> any_channel =
				(*cur_analog_segments_.begin()).first;

			shared_ptr<data::SignalBase> base = signalbase_from_channel(any_channel);
			assert(base);

			shared_ptr<data::Analog> data(base->analog_data());
			assert(data);

			new_segment_id = data->get_segment_count() - 1;
		}
	}

	if (new_segment_id > highest_segment_id_) {
		highest_segment_id_ = new_segment_id;
		new_segment(highest_segment_id_);
	}
}

void Session::signal_segment_completed()
{
	int segment_id = 0;

	for (const shared_ptr<data::SignalBase>& signalbase : signalbases_) {
		// We only care about analog and logic channels, not derived ones
		if (signalbase->type() == data::SignalBase::AnalogChannel) {
			segment_id = signalbase->analog_data()->get_segment_count() - 1;
			break;
		}

		if (signalbase->type() == data::SignalBase::LogicChannel) {
			segment_id = signalbase->logic_data()->get_segment_count() - 1;
			break;
		}
	}

	if (segment_id >= 0)
		segment_completed(segment_id);
}

#ifdef ENABLE_FLOW
bool Session::on_gst_bus_message(const Glib::RefPtr<Gst::Bus>& bus, const Glib::RefPtr<Gst::Message>& message)
{
	(void)bus;

	if ((message->get_source() == pipeline_) && \
		((message->get_message_type() == Gst::MESSAGE_EOS)))
		pipeline_done_cond_.notify_one();

	// TODO Also evaluate MESSAGE_STREAM_STATUS to receive error notifications

	return true;
}

Gst::FlowReturn Session::on_gst_new_sample()
{
	RefPtr<Gst::Sample> sample = sink_->pull_sample();
	RefPtr<Gst::Buffer> buf = sample->get_buffer();

	for (uint32_t block_id = 0; block_id < buf->n_memory(); block_id++) {
		RefPtr<Gst::Memory> buf_mem = buf->get_memory(block_id);
		Gst::MapInfo mapinfo;
		buf_mem->map(mapinfo, Gst::MAP_READ);

		shared_ptr<sigrok::Packet> logic_packet =
			sr_context->create_logic_packet(mapinfo.get_data(), buf->get_size(), 1);

		try {
			feed_in_logic(dynamic_pointer_cast<sigrok::Logic>(logic_packet->payload()));
		} catch (bad_alloc&) {
			out_of_memory_ = true;
			device_->stop();
			buf_mem->unmap(mapinfo);
			return Gst::FLOW_ERROR;
		}

		buf_mem->unmap(mapinfo);
	}

	return Gst::FLOW_OK;
}
#endif

void Session::feed_in_header()
{
	// Nothing to do here for now
}

void Session::feed_in_meta(shared_ptr<Meta> meta)
{
	for (auto& entry : meta->config()) {
		switch (entry.first->id()) {
		case SR_CONF_SAMPLERATE:
			cur_samplerate_ = g_variant_get_uint64(entry.second.gobj());
			break;
		default:
			qDebug() << "Received meta data key" << entry.first->id() << ", ignoring.";
			break;
		}
	}

	signals_changed();
}

void Session::feed_in_trigger()
{
	// The channel containing most samples should be most accurate
	uint64_t sample_count = 0;

	{
		for (const shared_ptr<pv::data::SignalData>& d : all_signal_data_) {
			assert(d);
			uint64_t temp_count = 0;

			const vector< shared_ptr<pv::data::Segment> > segments =
				d->segments();
			for (const shared_ptr<pv::data::Segment> &s : segments)
				temp_count += s->get_sample_count();

			if (temp_count > sample_count)
				sample_count = temp_count;
		}
	}

	uint32_t segment_id = 0;  // Default segment when no frames are used

	// If a frame began, we'd ideally be able to use the highest segment ID for
	// the trigger. However, as new segments are only created when logic or
	// analog data comes in, this doesn't work if the trigger appears right
	// after the beginning of the frame, before any sample data.
	// For this reason, we use highest segment ID + 1 if no sample data came in
	// yet and the highest segment ID otherwise.
	if (frame_began_) {
		segment_id = highest_segment_id_;
		if (!cur_logic_segment_ && (cur_analog_segments_.size() == 0))
			segment_id++;
	}

	// TODO Create timestamp from segment start time + segment's current sample count
	util::Timestamp timestamp = sample_count / get_samplerate();
	trigger_list_.emplace_back(segment_id, timestamp);
	trigger_event(segment_id, timestamp);
}

void Session::feed_in_frame_begin()
{
	frame_began_ = true;
}

void Session::feed_in_frame_end()
{
	if (!frame_began_)
		return;

	{
		lock_guard<recursive_mutex> lock(data_mutex_);

		if (cur_logic_segment_)
			cur_logic_segment_->set_complete();

		for (auto& entry : cur_analog_segments_) {
			shared_ptr<data::AnalogSegment> segment = entry.second;
			segment->set_complete();
		}

		cur_logic_segment_.reset();
		cur_analog_segments_.clear();
	}

	frame_began_ = false;

	signal_segment_completed();
}

void Session::feed_in_logic(shared_ptr<Logic> logic)
{
	if (logic->data_length() == 0) {
		qDebug() << "WARNING: Received logic packet with 0 samples.";
		return;
	}

	if (logic->unit_size() > 8)
		throw QString(tr("Can't handle more than 64 logic channels."));

	if (!cur_samplerate_)
		try {
			cur_samplerate_ = device_->read_config<uint64_t>(ConfigKey::SAMPLERATE);
		} catch (Error& e) {
			// Do nothing
		}

	lock_guard<recursive_mutex> lock(data_mutex_);

	if (!logic_data_) {
		// The only reason logic_data_ would not have been created is
		// if it was not possible to determine the signals when the
		// device was created.
		update_signals();
	}

	if (!cur_logic_segment_) {
		// This could be the first packet after a trigger
		set_capture_state(Running);

		// Create a new data segment
		cur_logic_segment_ = make_shared<data::LogicSegment>(
			*logic_data_, logic_data_->get_segment_count(),
			logic->unit_size(), cur_samplerate_);
		logic_data_->push_segment(cur_logic_segment_);

		signal_new_segment();
	}

	cur_logic_segment_->append_payload(logic);

	data_received();
}

void Session::feed_in_analog(shared_ptr<Analog> analog)
{
	if (analog->num_samples() == 0) {
		qDebug() << "WARNING: Received analog packet with 0 samples.";
		return;
	}

	if (!cur_samplerate_)
		try {
			cur_samplerate_ = device_->read_config<uint64_t>(ConfigKey::SAMPLERATE);
		} catch (Error& e) {
			// Do nothing
		}

	lock_guard<recursive_mutex> lock(data_mutex_);

	const vector<shared_ptr<Channel>> channels = analog->channels();
	bool sweep_beginning = false;

	unique_ptr<float[]> data(new float[analog->num_samples() * channels.size()]);
	analog->get_data_as_float(data.get());

	if (signalbases_.empty())
		update_signals();

	float *channel_data = data.get();
	for (auto& channel : channels) {
		shared_ptr<data::AnalogSegment> segment;

		// Try to get the segment of the channel
		const map< shared_ptr<Channel>, shared_ptr<data::AnalogSegment> >::
			iterator iter = cur_analog_segments_.find(channel);
		if (iter != cur_analog_segments_.end())
			segment = (*iter).second;
		else {
			// If no segment was found, this means we haven't
			// created one yet. i.e. this is the first packet
			// in the sweep containing this segment.
			sweep_beginning = true;

			// Find the analog data associated with the channel
			shared_ptr<data::SignalBase> base = signalbase_from_channel(channel);
			assert(base);

			shared_ptr<data::Analog> data(base->analog_data());
			assert(data);

			// Create a segment, keep it in the maps of channels
			segment = make_shared<data::AnalogSegment>(
				*data, data->get_segment_count(), cur_samplerate_);
			cur_analog_segments_[channel] = segment;

			// Push the segment into the analog data.
			data->push_segment(segment);

			signal_new_segment();
		}

		assert(segment);

		// Append the samples in the segment
		segment->append_interleaved_samples(channel_data++, analog->num_samples(),
			channels.size());
	}

	if (sweep_beginning) {
		// This could be the first packet after a trigger
		set_capture_state(Running);
	}

	data_received();
}

void Session::data_feed_in(shared_ptr<sigrok::Device> device,
	shared_ptr<Packet> packet)
{
	(void)device;

	assert(device);
	assert(device == device_->device());
	assert(packet);

	switch (packet->type()->id()) {
	case SR_DF_HEADER:
		feed_in_header();
		break;

	case SR_DF_META:
		feed_in_meta(dynamic_pointer_cast<Meta>(packet->payload()));
		break;

	case SR_DF_TRIGGER:
		feed_in_trigger();
		break;

	case SR_DF_LOGIC:
		try {
			feed_in_logic(dynamic_pointer_cast<Logic>(packet->payload()));
		} catch (bad_alloc&) {
			out_of_memory_ = true;
			device_->stop();
		}
		break;

	case SR_DF_ANALOG:
		try {
			feed_in_analog(dynamic_pointer_cast<Analog>(packet->payload()));
		} catch (bad_alloc&) {
			out_of_memory_ = true;
			device_->stop();
		}
		break;

	case SR_DF_FRAME_BEGIN:
		feed_in_frame_begin();
		break;

	case SR_DF_FRAME_END:
		feed_in_frame_end();
		break;

	case SR_DF_END:
		// Strictly speaking, this is performed when a frame end marker was
		// received, so there's no point doing this again. However, not all
		// devices use frames, and for those devices, we need to do it here.
		{
			lock_guard<recursive_mutex> lock(data_mutex_);

			if (cur_logic_segment_)
				cur_logic_segment_->set_complete();

			for (auto& entry : cur_analog_segments_) {
				shared_ptr<data::AnalogSegment> segment = entry.second;
				segment->set_complete();
			}

			cur_logic_segment_.reset();
			cur_analog_segments_.clear();
		}
		break;

	default:
		break;
	}
}

void Session::on_data_saved()
{
	data_saved_ = true;
}

#ifdef ENABLE_DECODE
void Session::on_new_decoders_selected(vector<const srd_decoder*> decoders)
{
	assert(decoders.size() > 0);

	shared_ptr<data::DecodeSignal> signal = add_decode_signal();

	if (signal)
		for (unsigned int i = 0; i < decoders.size(); i++) {
			const srd_decoder* d = decoders[i];
			signal->stack_decoder(d, !(i < decoders.size() - 1));
		}
}
#endif

} // namespace pv