ardour/libs/ardour/port_manager.cc

/*
    Copyright (C) 2013 Paul Davis

    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, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#ifdef COMPILER_MSVC
#include <io.h> // Microsoft's nearest equivalent to <unistd.h>
#include <ardourext/misc.h>
#else
#include <regex.h>
#endif

#include <glibmm/fileutils.h>
#include <glibmm/miscutils.h>

#include "pbd/error.h"

#include "ardour/async_midi_port.h"
#include "ardour/audio_backend.h"
#include "ardour/audio_port.h"
#include "ardour/debug.h"
#include "ardour/filesystem_paths.h"
#include "ardour/midi_port.h"
#include "ardour/midiport_manager.h"
#include "ardour/port_manager.h"
#include "ardour/profile.h"
#include "ardour/session.h"
#include "ardour/types_convert.h"

#include "pbd/i18n.h"

using namespace ARDOUR;
using namespace PBD;
using std::string;
using std::vector;

PortManager::PortManager ()
	: ports (new Ports)
	, _port_remove_in_progress (false)
	, _port_deletions_pending (8192) /* ick, arbitrary sizing */
	, midi_info_dirty (true)
{
	load_midi_port_info ();
}

void
PortManager::clear_pending_port_deletions ()
{
	Port* p;

	DEBUG_TRACE (DEBUG::Ports, string_compose ("pending port deletions: %1\n", _port_deletions_pending.read_space()));

	while (_port_deletions_pending.read (&p, 1) == 1) {
		delete p;
	}
}

void
PortManager::remove_all_ports ()
{
	/* make sure that JACK callbacks that will be invoked as we cleanup
	 * ports know that they have nothing to do.
	 */

	_port_remove_in_progress = true;

	/* process lock MUST be held by caller
	*/

	{
		RCUWriter<Ports> writer (ports);
		boost::shared_ptr<Ports> ps = writer.get_copy ();
		ps->clear ();
	}

	/* clear dead wood list in RCU */

	ports.flush ();

	/* clear out pending port deletion list. we know this is safe because
	 * the auto connect thread in Session is already dead when this is
	 * done. It doesn't use shared_ptr<Port> anyway.
	 */

	_port_deletions_pending.reset ();

	_port_remove_in_progress = false;
}


string
PortManager::make_port_name_relative (const string& portname) const
{
	if (!_backend) {
		return portname;
	}

	string::size_type colon = portname.find (':');

	if (colon == string::npos) {
		return portname;
	}

	if (portname.substr (0, colon) == _backend->my_name()) {
		return portname.substr (colon+1);
	}

	return portname;
}

string
PortManager::make_port_name_non_relative (const string& portname) const
{
	string str;

	if (portname.find_first_of (':') != string::npos) {
		return portname;
	}

	str  = _backend->my_name();
	str += ':';
	str += portname;

	return str;
}

std::string
PortManager::get_pretty_name_by_name(const std::string& portname) const
{
	PortEngine::PortHandle ph = _backend->get_port_by_name (portname);
	if (ph) {
		std::string value;
		std::string type;
		if (0 == _backend->get_port_property (ph,
					"http://jackaudio.org/metadata/pretty-name",
					value, type))
		{
			return value;
		}
	}
	return "";
}

bool
PortManager::port_is_mine (const string& portname) const
{
	if (!_backend) {
		return true;
	}

	string self = _backend->my_name();

	if (portname.find_first_of (':') != string::npos) {
		if (portname.substr (0, self.length ()) != self) {
                        return false;
                }
        }

        return true;
}

bool
PortManager::port_is_physical (const std::string& portname) const
{
	if (!_backend) {
		return false;
	}

	PortEngine::PortHandle ph = _backend->get_port_by_name (portname);
	if (!ph) {
		return false;
	}

	return _backend->port_is_physical (ph);
}

void
PortManager::filter_midi_ports (vector<string>& ports, MidiPortFlags include, MidiPortFlags exclude)
{
	if (!include && !exclude) {
		return;
	}

	for (vector<string>::iterator si = ports.begin(); si != ports.end(); ) {

		PortManager::MidiPortInformation mpi = midi_port_information (*si);

		if (mpi.pretty_name.empty()) {
			/* no information !!! */
			++si;
			continue;
		}

		if (include) {
			if ((mpi.properties & include) != include) {
				/* properties do not include requested ones */
				si = ports.erase (si);
				continue;
			}
		}

		if (exclude) {
			if ((mpi.properties & exclude)) {
				/* properties include ones to avoid */
				si = ports.erase (si);
				continue;
			}
		}

		++si;
	}
}

void
PortManager::get_physical_outputs (DataType type, std::vector<std::string>& s, MidiPortFlags include, MidiPortFlags exclude)
{
	if (!_backend) {
		s.clear ();
		return;
	}
	_backend->get_physical_outputs (type, s);
	filter_midi_ports (s, include, exclude);
}

void
PortManager::get_physical_inputs (DataType type, std::vector<std::string>& s, MidiPortFlags include, MidiPortFlags exclude)
{
	if (!_backend) {
		s.clear ();
		return;
	}

	_backend->get_physical_inputs (type, s);
	filter_midi_ports (s, include, exclude);
}

ChanCount
PortManager::n_physical_outputs () const
{
	if (!_backend) {
		return ChanCount::ZERO;
	}

	return _backend->n_physical_outputs ();
}

ChanCount
PortManager::n_physical_inputs () const
{
	if (!_backend) {
		return ChanCount::ZERO;
	}
	return _backend->n_physical_inputs ();
}

/** @param name Full or short name of port
 *  @return Corresponding Port or 0.
 */

boost::shared_ptr<Port>
PortManager::get_port_by_name (const string& portname)
{
	if (!_backend) {
		return boost::shared_ptr<Port>();
	}

        if (!port_is_mine (portname)) {
                /* not an ardour port */
                return boost::shared_ptr<Port> ();
        }

	boost::shared_ptr<Ports> pr = ports.reader();
	std::string rel = make_port_name_relative (portname);
	Ports::iterator x = pr->find (rel);

	if (x != pr->end()) {
		/* its possible that the port was renamed by some 3rd party and
		   we don't know about it. check for this (the check is quick
		   and cheap), and if so, rename the port (which will alter
		   the port map as a side effect).
		*/
		const std::string check = make_port_name_relative (_backend->get_port_name (x->second->port_handle()));
		if (check != rel) {
			x->second->set_name (check);
		}
		return x->second;
	}

        return boost::shared_ptr<Port> ();
}

void
PortManager::port_renamed (const std::string& old_relative_name, const std::string& new_relative_name)
{
	RCUWriter<Ports> writer (ports);
	boost::shared_ptr<Ports> p = writer.get_copy();
	Ports::iterator x = p->find (old_relative_name);

	if (x != p->end()) {
		boost::shared_ptr<Port> port = x->second;
		p->erase (x);
		p->insert (make_pair (new_relative_name, port));
	}
}

int
PortManager::get_ports (DataType type, PortList& pl)
{
	boost::shared_ptr<Ports> plist = ports.reader();
	for (Ports::iterator p = plist->begin(); p != plist->end(); ++p) {
		if (p->second->type() == type) {
			pl.push_back (p->second);
		}
	}
	return pl.size();
}

int
PortManager::get_ports (const string& port_name_pattern, DataType type, PortFlags flags, vector<string>& s)
{
	s.clear();

	if (!_backend) {
		return 0;
	}

	return _backend->get_ports (port_name_pattern, type, flags, s);
}

void
PortManager::port_registration_failure (const std::string& portname)
{
	if (!_backend) {
		return;
	}

	string full_portname = _backend->my_name();
	full_portname += ':';
	full_portname += portname;


	PortEngine::PortHandle p = _backend->get_port_by_name (full_portname);
	string reason;

	if (p) {
		reason = string_compose (_("a port with the name \"%1\" already exists: check for duplicated track/bus names"), portname);
	} else {
		reason = string_compose (_("No more ports are available. You will need to stop %1 and restart with more ports if you need this many tracks."), PROGRAM_NAME);
	}

	throw PortRegistrationFailure (string_compose (_("AudioEngine: cannot register port \"%1\": %2"), portname, reason).c_str());
}

struct PortDeleter
{
	void operator() (Port* p) {
		AudioEngine::instance()->add_pending_port_deletion (p);
	}
};

boost::shared_ptr<Port>
PortManager::register_port (DataType dtype, const string& portname, bool input, bool async, PortFlags flags)
{
	boost::shared_ptr<Port> newport;

	/* limit the possible flags that can be set */

	flags = PortFlags (flags & (Hidden|Shadow|IsTerminal));

	try {
		if (dtype == DataType::AUDIO) {
			DEBUG_TRACE (DEBUG::Ports, string_compose ("registering AUDIO port %1, input %2\n",
								   portname, input));
			newport.reset (new AudioPort (portname, PortFlags ((input ? IsInput : IsOutput) | flags)),
			               PortDeleter());
		} else if (dtype == DataType::MIDI) {
			if (async) {
				DEBUG_TRACE (DEBUG::Ports, string_compose ("registering ASYNC MIDI port %1, input %2\n",
									   portname, input));
				newport.reset (new AsyncMIDIPort (portname, PortFlags ((input ? IsInput : IsOutput) | flags)),
				               PortDeleter());
			} else {
				DEBUG_TRACE (DEBUG::Ports, string_compose ("registering MIDI port %1, input %2\n",
									   portname, input));
				newport.reset (new MidiPort (portname, PortFlags ((input ? IsInput : IsOutput) | flags)),
				               PortDeleter());
			}
		} else {
			throw PortRegistrationFailure("unable to create port (unknown type)");
		}

		RCUWriter<Ports> writer (ports);
		boost::shared_ptr<Ports> ps = writer.get_copy ();
		ps->insert (make_pair (make_port_name_relative (portname), newport));

		/* writer goes out of scope, forces update */

	}

	catch (PortRegistrationFailure& err) {
		throw err;
	} catch (std::exception& e) {
		throw PortRegistrationFailure(string_compose(
				_("unable to create port: %1"), e.what()).c_str());
	} catch (...) {
		throw PortRegistrationFailure("unable to create port (unknown error)");
	}

	DEBUG_TRACE (DEBUG::Ports, string_compose ("\t%2 port registration success, ports now = %1\n", ports.reader()->size(), this));
	return newport;
}

boost::shared_ptr<Port>
PortManager::register_input_port (DataType type, const string& portname, bool async, PortFlags extra_flags)
{
	return register_port (type, portname, true, async, extra_flags);
}

boost::shared_ptr<Port>
PortManager::register_output_port (DataType type, const string& portname, bool async, PortFlags extra_flags)
{
	return register_port (type, portname, false, async, extra_flags);
}

int
PortManager::unregister_port (boost::shared_ptr<Port> port)
{
	/* This is a little subtle. We do not call the backend's port
	 * unregistration code from here. That is left for the Port
	 * destructor. We are trying to drop references to the Port object
	 * here, so that its destructor will run and it will unregister itself.
	 */

	/* caller must hold process lock */

	{
		RCUWriter<Ports> writer (ports);
		boost::shared_ptr<Ports> ps = writer.get_copy ();
		Ports::iterator x = ps->find (make_port_name_relative (port->name()));

		if (x != ps->end()) {
			DEBUG_TRACE (DEBUG::Ports, string_compose ("removing %1 from port map (uc=%2)\n", port->name(), port.use_count()));
			ps->erase (x);
		}

		/* writer goes out of scope, forces update */
	}

	ports.flush ();

	return 0;
}

bool
PortManager::connected (const string& port_name)
{
	if (!_backend) {
		return false;
	}

	PortEngine::PortHandle handle = _backend->get_port_by_name (port_name);

	if (!handle) {
		return false;
	}

	return _backend->connected (handle);
}

bool
PortManager::physically_connected (const string& port_name)
{
	if (!_backend) {
		return false;
	}

	PortEngine::PortHandle handle = _backend->get_port_by_name (port_name);

	if (!handle) {
		return false;
	}

	return _backend->physically_connected (handle);
}

int
PortManager::get_connections (const string& port_name, std::vector<std::string>& s)
{
	if (!_backend) {
		s.clear ();
		return 0;
	}

	PortEngine::PortHandle handle = _backend->get_port_by_name (port_name);

	if (!handle) {
		s.clear ();
		return 0;
	}

	return _backend->get_connections (handle, s);
}

int
PortManager::connect (const string& source, const string& destination)
{
	int ret;

	string s = make_port_name_non_relative (source);
	string d = make_port_name_non_relative (destination);

	boost::shared_ptr<Port> src = get_port_by_name (s);
	boost::shared_ptr<Port> dst = get_port_by_name (d);

	if (src) {
		ret = src->connect (d);
	} else if (dst) {
		ret = dst->connect (s);
	} else {
		/* neither port is known to us ...hand-off to the PortEngine
		 */
		if (_backend) {
			ret = _backend->connect (s, d);
		} else {
			ret = -1;
		}
	}

	if (ret > 0) {
		/* already exists - no error, no warning */
	} else if (ret < 0) {
		error << string_compose(_("AudioEngine: cannot connect %1 (%2) to %3 (%4)"),
					source, s, destination, d)
		      << endmsg;
	}

	return ret;
}

int
PortManager::disconnect (const string& source, const string& destination)
{
	int ret;

	string s = make_port_name_non_relative (source);
	string d = make_port_name_non_relative (destination);

	boost::shared_ptr<Port> src = get_port_by_name (s);
	boost::shared_ptr<Port> dst = get_port_by_name (d);

	if (src) {
		ret = src->disconnect (d);
	} else if (dst) {
		ret = dst->disconnect (s);
	} else {
		/* neither port is known to us ...hand-off to the PortEngine
		 */
		if (_backend) {
			ret = _backend->disconnect (s, d);
		} else {
			ret = -1;
		}
	}
	return ret;
}

int
PortManager::disconnect (boost::shared_ptr<Port> port)
{
	return port->disconnect_all ();
}

int
PortManager::disconnect (std::string const & name)
{
	PortEngine::PortHandle ph = _backend->get_port_by_name (name);
	if (ph) {
		return _backend->disconnect_all (ph);
	}
	return -2;
}

int
PortManager::reestablish_ports ()
{
	Ports::iterator i;

	boost::shared_ptr<Ports> p = ports.reader ();

	DEBUG_TRACE (DEBUG::Ports, string_compose ("reestablish %1 ports\n", p->size()));

	for (i = p->begin(); i != p->end(); ++i) {
		if (i->second->reestablish ()) {
			error << string_compose (_("Re-establising port %1 failed"), i->second->name()) << endmsg;
			std::cerr << string_compose (_("Re-establising port %1 failed"), i->second->name()) << std::endl;
			break;
		}
	}

	if (i != p->end()) {
		/* failed */
		remove_all_ports ();
		return -1;
	}

	return 0;
}

int
PortManager::reconnect_ports ()
{
	boost::shared_ptr<Ports> p = ports.reader ();

	if (!Profile->get_trx()) {
		/* re-establish connections */

		DEBUG_TRACE (DEBUG::Ports, string_compose ("reconnect %1 ports\n", p->size()));

		for (Ports::iterator i = p->begin(); i != p->end(); ++i) {
			i->second->reconnect ();
		}
	}

	return 0;
}

void
PortManager::connect_callback (const string& a, const string& b, bool conn)
{
	boost::shared_ptr<Port> port_a;
	boost::shared_ptr<Port> port_b;
	Ports::iterator x;
	boost::shared_ptr<Ports> pr = ports.reader ();

	x = pr->find (make_port_name_relative (a));
	if (x != pr->end()) {
		port_a = x->second;
	}

	x = pr->find (make_port_name_relative (b));
	if (x != pr->end()) {
		port_b = x->second;
	}

	PortConnectedOrDisconnected (
		port_a, a,
		port_b, b,
		conn
		); /* EMIT SIGNAL */
}

void
PortManager::registration_callback ()
{
	if (!_port_remove_in_progress) {

		{
			Glib::Threads::Mutex::Lock lm (midi_port_info_mutex);
			midi_info_dirty = true;
		}

		PortRegisteredOrUnregistered (); /* EMIT SIGNAL */
	}
}

bool
PortManager::can_request_input_monitoring () const
{
	if (!_backend) {
		return false;
	}

	return _backend->can_monitor_input ();
}

void
PortManager::request_input_monitoring (const string& name, bool yn) const
{
	if (!_backend) {
		return;
	}

	PortEngine::PortHandle ph = _backend->get_port_by_name (name);

	if (ph) {
		_backend->request_input_monitoring (ph, yn);
	}
}

void
PortManager::ensure_input_monitoring (const string& name, bool yn) const
{
	if (!_backend) {
		return;
	}

	PortEngine::PortHandle ph = _backend->get_port_by_name (name);

	if (ph) {
		_backend->ensure_input_monitoring (ph, yn);
	}
}

uint32_t
PortManager::port_name_size() const
{
	if (!_backend) {
		return 0;
	}

	return _backend->port_name_size ();
}

string
PortManager::my_name() const
{
	if (!_backend) {
		return string();
	}

	return _backend->my_name();
}

int
PortManager::graph_order_callback ()
{
	if (!_port_remove_in_progress) {
		GraphReordered(); /* EMIT SIGNAL */
	}

	return 0;
}

void
PortManager::cycle_start (pframes_t nframes)
{
	Port::set_global_port_buffer_offset (0);
        Port::set_cycle_samplecnt (nframes);

	_cycle_ports = ports.reader ();

	for (Ports::iterator p = _cycle_ports->begin(); p != _cycle_ports->end(); ++p) {
		p->second->cycle_start (nframes);
	}
}

void
PortManager::cycle_end (pframes_t nframes)
{
	for (Ports::iterator p = _cycle_ports->begin(); p != _cycle_ports->end(); ++p) {
		p->second->cycle_end (nframes);
	}

	for (Ports::iterator p = _cycle_ports->begin(); p != _cycle_ports->end(); ++p) {
		p->second->flush_buffers (nframes);
	}

	_cycle_ports.reset ();

	/* we are done */
}

void
PortManager::silence (pframes_t nframes, Session *s)
{
	for (Ports::iterator i = _cycle_ports->begin(); i != _cycle_ports->end(); ++i) {
		if (s && i->second == s->mtc_output_port ()) {
			continue;
		}
		if (s && i->second == s->midi_clock_output_port ()) {
			continue;
		}
		if (s && i->second == s->ltc_output_port ()) {
			continue;
		}
		if (boost::dynamic_pointer_cast<AsyncMIDIPort>(i->second)) {
			continue;
		}
		if (i->second->sends_output()) {
			i->second->get_buffer(nframes).silence(nframes);
		}
	}
}

void
PortManager::silence_outputs (pframes_t nframes)
{
	std::vector<std::string> port_names;
	if (get_ports("", DataType::AUDIO, IsOutput, port_names)) {
		for (std::vector<std::string>::iterator p = port_names.begin(); p != port_names.end(); ++p) {
			if (!port_is_mine(*p)) {
				continue;
			}
			PortEngine::PortHandle ph = _backend->get_port_by_name (*p);
			if (!ph) {
				continue;
			}
			void *buf = _backend->get_buffer(ph, nframes);
			if (!buf) {
				continue;
			}
			memset (buf, 0, sizeof(float) * nframes);
		}
	}

	if (get_ports("", DataType::MIDI, IsOutput, port_names)) {
		for (std::vector<std::string>::iterator p = port_names.begin(); p != port_names.end(); ++p) {
			if (!port_is_mine(*p)) {
				continue;
			}
			PortEngine::PortHandle ph = _backend->get_port_by_name (*p);
			if (!ph) {
				continue;
			}
			void *buf = _backend->get_buffer(ph, nframes);
			if (!buf) {
				continue;
			}
			_backend->midi_clear (buf);
		}
	}
}

void
PortManager::check_monitoring ()
{
	for (Ports::iterator i = _cycle_ports->begin(); i != _cycle_ports->end(); ++i) {

		bool x;

		if (i->second->last_monitor() != (x = i->second->monitoring_input ())) {
			i->second->set_last_monitor (x);
			/* XXX I think this is dangerous, due to
			   a likely mutex in the signal handlers ...
			*/
			i->second->MonitorInputChanged (x); /* EMIT SIGNAL */
		}
	}
}

void
PortManager::fade_out (gain_t base_gain, gain_t gain_step, pframes_t nframes)
{
	for (Ports::iterator i = _cycle_ports->begin(); i != _cycle_ports->end(); ++i) {

		if (i->second->sends_output()) {

			boost::shared_ptr<AudioPort> ap = boost::dynamic_pointer_cast<AudioPort> (i->second);
			if (ap) {
				Sample* s = ap->engine_get_whole_audio_buffer ();
				gain_t g = base_gain;

				for (pframes_t n = 0; n < nframes; ++n) {
					*s++ *= g;
					g -= gain_step;
				}
			}
		}
	}
}

PortEngine&
PortManager::port_engine()
{
	assert (_backend);
	return *_backend;
}

bool
PortManager::port_is_control_only (std::string const& name)
{
	static regex_t compiled_pattern;
	static string pattern;

	if (pattern.empty()) {

		/* This is a list of regular expressions that match ports
		 * related to physical MIDI devices that we do not want to
		 * expose as normal physical ports.
		 */

		const char * const control_only_ports[] = {
			X_(".*Ableton Push.*"),
			X_(".*FaderPort .*"),
			X_(".*FaderPort8 .*"),
		};

		pattern = "(";
		for (size_t n = 0; n < sizeof (control_only_ports)/sizeof (control_only_ports[0]); ++n) {
			if (n > 0) {
				pattern += '|';
			}
			pattern += control_only_ports[n];
		}
		pattern += ')';

		regcomp (&compiled_pattern, pattern.c_str(), REG_EXTENDED|REG_NOSUB);
	}

	return regexec (&compiled_pattern, name.c_str(), 0, 0, 0) == 0;
}

PortManager::MidiPortInformation
PortManager::midi_port_information (std::string const & name)
{
	Glib::Threads::Mutex::Lock lm (midi_port_info_mutex);

	fill_midi_port_info_locked ();

	MidiPortInfo::iterator x = midi_port_info.find (name);

	if (x != midi_port_info.end()) {
		return x->second;
	}

	return MidiPortInformation ();
}

void
PortManager::get_known_midi_ports (vector<string>& copy)
{
	Glib::Threads::Mutex::Lock lm (midi_port_info_mutex);

	fill_midi_port_info_locked ();

	for (MidiPortInfo::const_iterator x = midi_port_info.begin(); x != midi_port_info.end(); ++x) {
		copy.push_back (x->first);
	}
}

void
PortManager::get_midi_selection_ports (vector<string>& copy)
{
	Glib::Threads::Mutex::Lock lm (midi_port_info_mutex);

	fill_midi_port_info_locked ();

	for (MidiPortInfo::const_iterator x = midi_port_info.begin(); x != midi_port_info.end(); ++x) {
		if (x->second.properties & MidiPortSelection) {
			copy.push_back (x->first);
		}
	}
}

void
PortManager::set_midi_port_pretty_name (string const & port, string const & pretty)
{
	{
		Glib::Threads::Mutex::Lock lm (midi_port_info_mutex);

		fill_midi_port_info_locked ();

		MidiPortInfo::iterator x = midi_port_info.find (port);
		if (x == midi_port_info.end()) {
			return;
		}
		x->second.pretty_name = pretty;
	}

	/* push into back end */

	PortEngine::PortHandle ph = _backend->get_port_by_name (port);

	if (ph) {
		_backend->set_port_property (ph, "http://jackaudio.org/metadata/pretty-name", pretty, string());
	}

	MidiPortInfoChanged (); /* EMIT SIGNAL*/
}

void
PortManager::add_midi_port_flags (string const & port, MidiPortFlags flags)
{
	bool emit = false;

	{
		Glib::Threads::Mutex::Lock lm (midi_port_info_mutex);

		fill_midi_port_info_locked ();

		MidiPortInfo::iterator x = midi_port_info.find (port);
		if (x != midi_port_info.end()) {
			if ((x->second.properties & flags) != flags) { // at least one missing
				x->second.properties = MidiPortFlags (x->second.properties | flags);
				emit = true;
			}
		}
	}

	if (emit) {
		if (flags & MidiPortSelection) {
			MidiSelectionPortsChanged (); /* EMIT SIGNAL */
		}

		if (flags != MidiPortSelection) {
			MidiPortInfoChanged (); /* EMIT SIGNAL */
		}

		save_midi_port_info ();
	}
}

void
PortManager::remove_midi_port_flags (string const & port, MidiPortFlags flags)
{
	bool emit = false;

	{
		Glib::Threads::Mutex::Lock lm (midi_port_info_mutex);

		fill_midi_port_info_locked ();

		MidiPortInfo::iterator x = midi_port_info.find (port);
		if (x != midi_port_info.end()) {
			if (x->second.properties & flags) { // at least one is set
				x->second.properties = MidiPortFlags (x->second.properties & ~flags);
				emit = true;
			}
		}
	}

	if (emit) {
		if (flags & MidiPortSelection) {
			MidiSelectionPortsChanged (); /* EMIT SIGNAL */
		}

		if (flags != MidiPortSelection) {
			MidiPortInfoChanged (); /* EMIT SIGNAL */
		}

		save_midi_port_info ();
	}
}

string
PortManager::midi_port_info_file ()
{
	return Glib::build_filename (user_config_directory(), X_("midi_port_info"));
}

void
PortManager::save_midi_port_info ()
{
	string path = midi_port_info_file ();

	XMLNode* root = new XMLNode (X_("MidiPortInfo"));

	{
		Glib::Threads::Mutex::Lock lm (midi_port_info_mutex);

		if (midi_port_info.empty()) {
			delete root;
			return;
		}

		for (MidiPortInfo::iterator i = midi_port_info.begin(); i != midi_port_info.end(); ++i) {
			XMLNode* node = new XMLNode (X_("port"));
			node->set_property (X_("name"), i->first);
			node->set_property (X_("input"), i->second.input);
			node->set_property (X_("properties"), i->second.properties);
			root->add_child_nocopy (*node);
		}
	}

	XMLTree tree;

	tree.set_root (root);

	if (!tree.write (path)) {
		error << string_compose (_("Could not save MIDI port info to %1"), path) << endmsg;
	}
}

void
PortManager::load_midi_port_info ()
{
	string path = midi_port_info_file ();
	XMLTree tree;

	if (!Glib::file_test (path, Glib::FILE_TEST_EXISTS)) {
		return;
	}

	if (!tree.read (path)) {
		error << string_compose (_("Cannot load MIDI port info from %1"), path) << endmsg;
		return;
	}

	midi_port_info.clear ();

	for (XMLNodeConstIterator i = tree.root()->children().begin(); i != tree.root()->children().end(); ++i) {
		MidiPortInformation mpi;
		string name;

		if (!(*i)->get_property (X_("name"), name) ||
		    !(*i)->get_property (X_("input"), mpi.input) ||
		    !(*i)->get_property (X_("properties"), mpi.properties)) {
			continue;
		}

		midi_port_info.insert (make_pair (name, mpi));
	}
}

void
PortManager::fill_midi_port_info ()
{
	Glib::Threads::Mutex::Lock lm (midi_port_info_mutex);
	fill_midi_port_info_locked ();
}

void
PortManager::fill_midi_port_info_locked ()
{
	/* MIDI info mutex MUST be held */

	if (!midi_info_dirty) {
		return;
	}

	std::vector<string> ports;

	AudioEngine::instance()->get_ports (string(), DataType::MIDI, IsOutput, ports);

	for (vector<string>::iterator p = ports.begin(); p != ports.end(); ++p) {

		if (port_is_mine (*p)) {
			continue;
		}

		if (midi_port_info.find (*p) == midi_port_info.end()) {
			MidiPortInformation mpi;
			mpi.pretty_name = *p;
			mpi.input = true;

			if (port_is_control_only (*p)) {
				mpi.properties = MidiPortFlags (mpi.properties | MidiPortControl);
			}
#ifdef LINUX
			if ((*p.find (X_("Midi Through")) != string::npos ||
			     (*p).find (X_("Midi-Through")) != string::npos))
			{
				mpi.properties = MidiPortFlags (mpi.properties | MidiPortVirtual);
			}
#endif
			midi_port_info.insert (make_pair (*p, mpi));
		}
	}

	AudioEngine::instance()->get_ports (string(), DataType::MIDI, IsInput, ports);

	for (vector<string>::iterator p = ports.begin(); p != ports.end(); ++p) {

		if (port_is_mine (*p)) {
			continue;
		}

		if (midi_port_info.find (*p) == midi_port_info.end()) {
			MidiPortInformation mpi;
			mpi.pretty_name = *p;
			mpi.input = false;

			if (port_is_control_only (*p)) {
				mpi.properties = MidiPortFlags (mpi.properties | MidiPortControl);
			}
#ifdef LINUX
			if ((*p.find (X_("Midi Through")) != string::npos ||
			     (*p).find (X_("Midi-Through")) != string::npos))
			{
				mpi.properties = MidiPortFlags (mpi.properties | MidiPortVirtual);
			}
#endif
			midi_port_info.insert (make_pair (*p, mpi));
		}
	}

	/* now push/pull pretty name information between backend and the
	 * PortManager
	 */

	// rg: I don't understand what this attempts to solve
	//
	// Naming ports should be left to the backend:
	// Ardour cannot associate numeric IDs with corresponding hardware.
	// (see also 7dde6c3b)

	for (MidiPortInfo::iterator x = midi_port_info.begin(); x != midi_port_info.end(); ++x) {
		PortEngine::PortHandle ph = _backend->get_port_by_name (x->first);

		if (!ph) {
			/* port info saved from some condition where this port
			 * existed, but no longer does (i.e. device unplugged
			 * at present)
			 */
			continue;
		}

		if (!x->second.pretty_name.empty () && x->second.pretty_name != x->first) {
			/* name set in port info ... propagate */
			_backend->set_port_property (ph, "http://jackaudio.org/metadata/pretty-name", x->second.pretty_name, string());
		} else {
			/* check with backend for pre-existing pretty name */
			string value;
			string type;
			if (0 == _backend->get_port_property (ph,
			                                      "http://jackaudio.org/metadata/pretty-name",
			                                      value, type)) {
				x->second.pretty_name = value;
			}
		}
	}

	midi_info_dirty = false;
}