livetrax/libs/surfaces/mackie/surface_port.cc

/*
	Copyright (C) 2006,2007 John Anderson

	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.
*/
#include "surface_port.h"

#include "mackie_control_exception.h"
#include "controls.h"

#include "midi++/types.h"
#include "midi++/port.h"
#include "midi++/manager.h"
#include <sigc++/sigc++.h>
#include <boost/shared_array.hpp>

#include "i18n.h"

#include <sstream>

#include <cstring>
#include <cerrno>

using namespace std;
using namespace Mackie;

SurfacePort::SurfacePort()
	: _input_port (0), _output_port (0), _number (0), _active (false)
{
}

/** @param input_port Input MIDI::Port; this object takes responsibility for removing it from
 *  the MIDI::Manager and destroying it.
 *  @param output_port Output MIDI::Port; responsibility similarly taken.
 */
SurfacePort::SurfacePort (MIDI::Port & input_port, MIDI::Port & output_port, int number)
	: _input_port (&input_port), _output_port (&output_port), _number (number), _active (false)
{
}

SurfacePort::~SurfacePort()
{
#ifdef PORT_DEBUG
	cout << "~SurfacePort::SurfacePort()" << endl;
#endif
	// make sure another thread isn't reading or writing as we close the port
	Glib::RecMutex::Lock lock (_rwlock);
	_active = false;

	MIDI::Manager* mm = MIDI::Manager::instance ();
	
	if (_input_port) {
		mm->remove_port (_input_port);
		delete _input_port;
	}

	if (_output_port) {
		mm->remove_port (_output_port);
		delete _output_port;
	}
	
#ifdef PORT_DEBUG
	cout << "~SurfacePort::SurfacePort() finished" << endl;
#endif
}

// wrapper for one day when strerror_r is working properly
string fetch_errmsg (int error_number)
{
	char * msg = strerror (error_number);
	return msg;
}
	
MidiByteArray SurfacePort::read()
{
	const int max_buf_size = 512;
	MIDI::byte buf[max_buf_size];
	MidiByteArray retval;

	// check active. Mainly so that the destructor
	// doesn't destroy the mutex while it's still locked
	if  (!active()) {
		return retval;
	}
	
	// return nothing read if the lock isn't acquired
#if 0
	Glib::RecMutex::Lock lock (_rwlock, Glib::TRY_LOCK);
		
	if  (!lock.locked()) {
		cout << "SurfacePort::read not locked" << endl;
		return retval;
	}
	
	// check active again - destructor sequence
	if  (!active()) return retval;
#endif
	
	// read port and copy to return value
	int nread = input_port().read (buf, sizeof (buf));

	if (nread >= 0) {
		retval.copy (nread, buf);
		if ((size_t) nread == sizeof (buf)) {
#ifdef PORT_DEBUG
			cout << "SurfacePort::read recursive" << endl;
#endif
			retval << read();
		}
	} else {
		if  (errno != EAGAIN) {
			ostringstream os;
			os << "Surface: error reading from port: " << input_port().name();
			os << ": " << errno << fetch_errmsg (errno);

			cout << os.str() << endl;
			inactive_event();
			throw MackieControlException (os.str());
		}
	}
#ifdef PORT_DEBUG
	cout << "SurfacePort::read: " << retval << endl;
#endif
	return retval;
}

void SurfacePort::write (const MidiByteArray & mba)
{
	if (mba.empty()) {
		return;
	}

#ifdef PORT_DEBUG
	cout << "SurfacePort::write: " << mba << " to " << output_port().name() << endl;
#endif
	
	// check active before and after lock - to make sure
	// that the destructor doesn't destroy the mutex while
	// it's still in use
	if (!active()) return;
	Glib::RecMutex::Lock lock (_rwlock);
	if (!active()) return;

	int count = output_port().write (mba.bytes().get(), mba.size(), 0);
	if  (count != (int)mba.size()) {
		if  (errno == 0) {
			cout << "port overflow on " << output_port().name() << ". Did not write all of " << mba << endl;
		} else if  (errno != EAGAIN) {
			ostringstream os;
			os << "Surface: couldn't write to port " << output_port().name();
			os << ", error: " << fetch_errmsg (errno) << "(" << errno << ")";
			
			cout << os.str() << endl;
			inactive_event();
		}
	}
#ifdef PORT_DEBUG
	cout << "SurfacePort::wrote " << count << endl;
#endif
}

void SurfacePort::write_sysex (const MidiByteArray & mba)
{
	if (mba.empty()) {
		return;
	}

	MidiByteArray buf;
	buf << sysex_hdr() << mba << MIDI::eox;
	write (buf);
}

void SurfacePort::write_sysex (MIDI::byte msg)
{
	MidiByteArray buf;
	buf << sysex_hdr() << msg << MIDI::eox;
	write (buf);
}

ostream & Mackie::operator <<  (ostream & os, const SurfacePort & port)
{
	os << "{ ";
	os << "name: " << port.input_port().name() << " " << port.output_port().name();
	os << "; ";
	os << " }";
	return os;
}