--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/JackCommand.h	Mon May 18 18:04:12 2020 +0200
@@ -0,0 +1,201 @@
+/**
+ * Relational pipes
+ * Copyright © 2020 František Kučera (Frantovo.cz, GlobalCode.info)
+ *
+ * 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, version 3 of the License.
+ *
+ * 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/>.
+ */
+#pragma once
+
+#include <cstdlib>
+#include <cstring>
+#include <memory>
+#include <unistd.h>
+#include <pthread.h>
+#include <sys/mman.h>
+#include <atomic>
+
+#include <jack/jack.h>
+#include <jack/midiport.h>
+#include <jack/ringbuffer.h>
+
+#include <relpipe/writer/RelationalWriter.h>
+#include <relpipe/writer/RelpipeWriterException.h>
+#include <relpipe/writer/AttributeMetadata.h>
+#include <relpipe/writer/Factory.h>
+#include <relpipe/writer/TypeId.h>
+#include <relpipe/cli/CLI.h>
+
+#include "JackException.h"
+
+using namespace relpipe::writer;
+
+namespace relpipe {
+namespace in {
+namespace jack {
+
+int enqueueMessage(jack_nframes_t frames, void* arg);
+
+class JackCommand {
+private:
+	jack_port_t* jackPort = nullptr;
+	jack_ringbuffer_t* ringBuffer = nullptr;
+	pthread_mutex_t messageThreadLock = PTHREAD_MUTEX_INITIALIZER;
+	pthread_cond_t dataReady = PTHREAD_COND_INITIALIZER;
+
+	std::atomic<bool> continueProcessing{true};
+
+	const int RING_BUFFER_SIZE = 100;
+
+	struct MidiMessage {
+		uint8_t buffer[4096];
+		uint32_t size;
+		uint32_t time;
+	};
+
+public:
+
+	int enqueueMessage(jack_nframes_t frames) {
+		void* buffer = jack_port_get_buffer(jackPort, frames);
+		if (buffer == nullptr) throw JackException(L"Unable to get port buffer."); // TODO: exception in RT callback?
+
+		for (jack_nframes_t i = 0, eventCount = jack_midi_get_event_count(buffer); i < eventCount; i++) {
+			jack_midi_event_t event;
+			int noData = jack_midi_event_get(&event, buffer, i);
+			if (noData) continue;
+
+			if (event.size > sizeof (MidiMessage::buffer)) {
+				// TODO: should not printf in RT callback:
+				fwprintf(stderr, L"Error: MIDI message was too large → skipping event. Maximum allowed size: %lu bytes.\n", sizeof (MidiMessage::buffer));
+			} else if (jack_ringbuffer_write_space(ringBuffer) >= sizeof (MidiMessage)) {
+				MidiMessage m;
+				m.time = event.time;
+				m.size = event.size;
+				memcpy(m.buffer, event.buffer, event.size);
+				jack_ringbuffer_write(ringBuffer, (const char *) &m, sizeof (MidiMessage));
+			} else {
+				// TODO: should not printf in RT callback:
+				fwprintf(stderr, L"Error: ring buffer is full → skipping event.\n");
+			}
+		}
+
+		// TODO: just count skipped events and bytes and report them in next successful message instead of printing to STDERR
+
+		if (pthread_mutex_trylock(&messageThreadLock) == 0) {
+			pthread_cond_signal(&dataReady);
+			pthread_mutex_unlock(&messageThreadLock);
+		}
+
+		return 0;
+	}
+
+private:
+
+	static void writeRecord(std::shared_ptr<RelationalWriter> writer,
+			string_t eventType, integer_t channel,
+			boolean_t noteOn, integer_t pitch, integer_t velocity,
+			integer_t controllerId, integer_t value) {
+		writer->writeAttribute(eventType);
+		writer->writeAttribute(&channel, typeid (channel));
+		writer->writeAttribute(&noteOn, typeid (noteOn));
+		writer->writeAttribute(&pitch, typeid (pitch));
+		writer->writeAttribute(&velocity, typeid (velocity));
+		writer->writeAttribute(&controllerId, typeid (controllerId));
+		writer->writeAttribute(&value, typeid (value));
+	}
+
+	void processMessage(std::shared_ptr<RelationalWriter> writer, MidiMessage* event) {
+		if (event->size == 0) {
+			return;
+		} else {
+			uint8_t type = event->buffer[0] & 0xF0;
+			uint8_t channel = event->buffer[0] & 0x0F;
+
+			// TODO: write timestamp, message number
+			// TODO: write raw buffer in hex
+
+			if ((type == 0x90 || type == 0x80) && event->size == 3) {
+				writeRecord(writer, L"note", channel, type == 0x90, event->buffer[1], event->buffer[2], 0, 0);
+			} else if (type == 0xB0 && event->size == 3) {
+				writeRecord(writer, L"control", channel, false, 0, 0, event->buffer[1], event->buffer[2]);
+			}
+		}
+	}
+
+public:
+
+	void finish(int sig) {
+		continueProcessing = false;
+	}
+
+	void processJackStream(ostream &output) {
+		// Relation headers:
+		std::shared_ptr<RelationalWriter> writer(Factory::create(output));
+		vector<AttributeMetadata> metadata;
+		metadata.push_back({L"event", TypeId::STRING});
+		metadata.push_back({L"channel", TypeId::INTEGER});
+		metadata.push_back({L"note_on", TypeId::BOOLEAN});
+		metadata.push_back({L"note_pitch", TypeId::INTEGER});
+		metadata.push_back({L"note_velocity", TypeId::INTEGER});
+		metadata.push_back({L"controller_id", TypeId::INTEGER});
+		metadata.push_back({L"controller_value", TypeId::INTEGER});
+		writer->startRelation(L"midi", metadata, true);
+		output.flush();
+
+		// Initialize JACK connection:
+		std::string clientName = "relpipe-in-jack";
+		jack_client_t* client = jack_client_open(clientName.c_str(), JackNullOption, nullptr);
+		if (client == nullptr) throw JackException(L"Could not create JACK client.");
+
+		ringBuffer = jack_ringbuffer_create(RING_BUFFER_SIZE * sizeof (MidiMessage));
+
+		jack_set_process_callback(client, relpipe::in::jack::enqueueMessage, this);
+		// TODO: report also other events (connections etc.)
+
+		jackPort = jack_port_register(client, "input", JACK_DEFAULT_MIDI_TYPE, JackPortIsInput, 0);
+		if (jackPort == nullptr) throw JackException(L"Could not register port.");
+
+		if (mlockall(MCL_CURRENT | MCL_FUTURE)) fwprintf(stderr, L"Warning: Can not lock memory.\n");
+
+		int jackError = jack_activate(client);
+		if (jackError) throw JackException(L"Could not activate client.");
+
+		// Process messages from the ring buffer queue:
+		pthread_mutex_lock(&messageThreadLock);
+		while (continueProcessing) {
+			const size_t queuedMessages = jack_ringbuffer_read_space(ringBuffer) / sizeof (MidiMessage);
+			for (size_t i = 0; i < queuedMessages; ++i) {
+				MidiMessage m;
+				jack_ringbuffer_read(ringBuffer, (char*) &m, sizeof (MidiMessage));
+				processMessage(writer, &m);
+				output.flush();
+			}
+			pthread_cond_wait(&dataReady, &messageThreadLock);
+		}
+		pthread_mutex_unlock(&messageThreadLock);
+
+		// Close JACK connection:
+		jack_deactivate(client);
+		jack_client_close(client);
+		jack_ringbuffer_free(ringBuffer);
+	}
+
+};
+
+int enqueueMessage(jack_nframes_t frames, void* arg) {
+	JackCommand* instance = (JackCommand*) arg;
+	return instance->enqueueMessage(frames);
+}
+
+}
+}
+}