franta-hg@2: /**
franta-hg@2:  * DJM-Fix
franta-hg@2:  * Copyright © 2020 František Kučera (Frantovo.cz, GlobalCode.info)
franta-hg@2:  *
franta-hg@2:  * This program is free software: you can redistribute it and/or modify
franta-hg@2:  * it under the terms of the GNU General Public License as published by
franta-hg@2:  * the Free Software Foundation, version 3 of the License.
franta-hg@2:  *
franta-hg@2:  * This program is distributed in the hope that it will be useful,
franta-hg@2:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
franta-hg@2:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
franta-hg@2:  * GNU General Public License for more details.
franta-hg@2:  *
franta-hg@2:  * You should have received a copy of the GNU General Public License
franta-hg@2:  * along with this program. If not, see <http://www.gnu.org/licenses/>.
franta-hg@2:  */
franta-hg@2: #include <iostream>
franta-hg@5: #include <stdexcept>
franta-hg@5: #include <thread>
franta-hg@9: #include <mutex>
franta-hg@5: #include <atomic>
franta-hg@2: 
franta-hg@3: #include <alsa/asoundlib.h>
franta-hg@3: 
franta-hg@2: #include "AlsaBridge.h"
franta-hg@2: 
franta-hg@2: namespace djmfix {
franta-hg@2: namespace alsa {
franta-hg@2: 
franta-hg@2: class AlsaBridgeImpl : public AlsaBridge, private djmfix::MidiSender {
franta-hg@2: private:
franta-hg@2: 	djmfix::DJMFix* djmFix;
franta-hg@5: 	snd_rawmidi_t* input;
franta-hg@5: 	snd_rawmidi_t* output;
franta-hg@5: 	std::thread receivingThread;
franta-hg@9: 	std::recursive_mutex midiMutex;
franta-hg@5: 	std::atomic<bool> stopped{false};
franta-hg@5: 
franta-hg@5: 	void run() {
franta-hg@5: 		while (!stopped) {
franta-hg@9: 			{
franta-hg@9: 				std::lock_guard<std::recursive_mutex> lock(midiMutex);
franta-hg@9: 				// TODO: poll
franta-hg@9: 				uint8_t buffer[256];
franta-hg@9: 				ssize_t length = snd_rawmidi_read(input, buffer, sizeof (buffer));
franta-hg@9: 				if (length > 0 && length <= sizeof (buffer)) {
franta-hg@9: 					// TODO: multiple messages combined together?
franta-hg@9: 					djmFix->receive(MidiMessage(buffer, buffer + length));
franta-hg@9: 				}
franta-hg@5: 			}
franta-hg@5: 			std::this_thread::sleep_for(std::chrono::milliseconds(100));
franta-hg@5: 		}
franta-hg@5: 	}
franta-hg@2: public:
franta-hg@2: 
franta-hg@5: 	AlsaBridgeImpl(djmfix::DJMFix* djmFix, const std::string& deviceName) : djmFix(djmFix) {
franta-hg@5: 		if (djmFix == nullptr) throw std::invalid_argument("need a djmFix for AlsaBridge");
franta-hg@5: 
franta-hg@5: 		int error = snd_rawmidi_open(&input, &output, deviceName.c_str(), SND_RAWMIDI_NONBLOCK);
franta-hg@5: 		if (error) throw std::invalid_argument("unable to open ALSA device");
franta-hg@5: 
franta-hg@5: 
franta-hg@2: 		djmFix->setMidiSender(this);
franta-hg@2: 	}
franta-hg@2: 
franta-hg@2: 	virtual ~AlsaBridgeImpl() {
franta-hg@5: 		// TODO: do not use raw/exclusive access to the device
franta-hg@5: 		snd_rawmidi_close(input);
franta-hg@5: 		snd_rawmidi_close(output);
franta-hg@2: 		std::cerr << "~AlsaBridgeImpl()" << std::endl; // TODO: do not mess STDIO
franta-hg@2: 	}
franta-hg@2: 
franta-hg@2: 	virtual void start() override {
franta-hg@2: 		djmFix->start();
franta-hg@5: 		receivingThread = std::thread(&AlsaBridgeImpl::run, this);
franta-hg@2: 	}
franta-hg@2: 
franta-hg@2: 	virtual void stop() override {
franta-hg@5: 		stopped = true;
franta-hg@5: 		receivingThread.join();
franta-hg@2: 		djmFix->stop();
franta-hg@2: 	}
franta-hg@2: 
franta-hg@2: 	virtual void send(MidiMessage midiMessage) override {
franta-hg@9: 		std::lock_guard<std::recursive_mutex> lock(midiMutex);
franta-hg@5: 		ssize_t length = snd_rawmidi_write(output, midiMessage.data(), midiMessage.size());
franta-hg@5: 		std::cerr << "AlsaBridgeImpl::send(): length = " << length << std::endl; // TODO: do not mess STDIO
franta-hg@2: 	}
franta-hg@2: 
franta-hg@2: };
franta-hg@2: 
franta-hg@5: AlsaBridge* create(djmfix::DJMFix* djmFix, const std::string& deviceName) {
franta-hg@5: 	return new AlsaBridgeImpl(djmFix, deviceName);
franta-hg@2: }
franta-hg@2: 
franta-hg@2: }
franta-hg@2: }