/**
* 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 <memory>
#include <atomic>
#include <string>
#include <cstring>
#include <vector>
#include <codecvt>
#include <sys/mman.h>
#include <unistd.h>
#include <pthread.h>
#include <jack/jack.h>
#include <jack/midiport.h>
#include <jack/ringbuffer.h>
#include <relpipe/common/type/typedefs.h>
#include <relpipe/reader/TypeId.h>
#include <relpipe/reader/handlers/RelationalReaderStringHandler.h>
#include <relpipe/reader/handlers/AttributeMetadata.h>
#include "Configuration.h"
#include "JackException.h"
namespace relpipe {
namespace out {
namespace jack {
int dequeueMessages(jack_nframes_t frames, void* arg);
class JackHandler : public relpipe::reader::handlers::RelationalReaderStringHandler {
private:
Configuration& configuration;
std::wstring_convert<std::codecvt_utf8<wchar_t>> convertor; // TODO: local system encoding
std::atomic<bool> continueProcessing{true};
/**
* Is passed through the ring buffer
* from the relpipe-reading thread to the jack-writing thread (callback).
*/
struct MidiMessage {
uint8_t buffer[4096] = {0};
size_t size;
/**
* Time in micro seconds;
* starts at the beginning of the playback.
*/
relpipe::common::type::Integer time;
};
/**
* JACK callbacks (called from the real-time thread)
*/
class RealTimeContext {
private:
jack_nframes_t startFrame = 0;
public:
jack_client_t* jackClient = nullptr;
jack_port_t* jackPort = nullptr;
jack_ringbuffer_t* ringBuffer = nullptr;
pthread_mutex_t processingLock = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t processingDone = PTHREAD_COND_INITIALIZER;
const int RING_BUFFER_SIZE = 100;
int processCallback(jack_nframes_t frames) {
jack_nframes_t lastFrame = jack_last_frame_time(jackClient);
void* jackPortBuffer = jack_port_get_buffer(jackPort, frames); // jack_port_get_buffer() must be called outside the loop, otherwise it will multiply the MIDI events
jack_midi_clear_buffer(jackPortBuffer);
MidiMessage m;
while (jack_ringbuffer_peek(ringBuffer, (char*) &m, sizeof (m)) == sizeof (m)) {
if (startFrame == 0) startFrame = lastFrame;
jack_nframes_t eventFrame = std::max(0L, (m.time * jack_get_sample_rate(jackClient) / 1000 / 1000) - (lastFrame - startFrame));
// If std::max() does its job, the message comes from the past and missed its cycle → we will send it now rather than lose it completely.
if (eventFrame < frames) {
jack_midi_data_t* midiData = jack_midi_event_reserve(jackPortBuffer, eventFrame, m.size);
if (midiData) {
memcpy(midiData, m.buffer, m.size);
jack_ringbuffer_read_advance(ringBuffer, sizeof (m));
} // else = error: not enough space; will be kept in the ring buffer and sent in the next cycle
} else {
/**
* This message does not belong to this cycle.
* Its time will come later.
* For now, it stays in the ring buffer.
*/
break;
}
}
if (pthread_mutex_trylock(&processingLock) == 0) {
pthread_cond_signal(&processingDone);
pthread_mutex_unlock(&processingLock);
}
return 0;
}
int syncCallback(jack_transport_state_t state, jack_position_t* position) {
return true;
}
static int processCallback(jack_nframes_t frames, void* instance) {
return static_cast<RealTimeContext*> (instance)->processCallback(frames);
}
static int syncCallback(jack_transport_state_t state, jack_position_t* position, void* instance) {
return static_cast<RealTimeContext*> (instance)->syncCallback(state, position);
}
} realTimeContext;
/**
* Temporary storage of values read from relational input.
*/
class RelationContext {
public:
bool skip = false;
std::vector<relpipe::reader::handlers::AttributeMetadata> attributes;
bool hasAttribute(const relpipe::common::type::StringX& name) {
for (auto a : attributes) if (a.getAttributeName() == name) return true;
return false;
}
class RecordContext {
public:
enum class Event {
NOTE,
CONTROL,
SYSEX,
CONNECT,
DISCONNECT,
UNKNOWN
};
static Event parseEventType(const relpipe::common::type::StringX& name) {
if (name == L"note") return Event::NOTE;
else if (name == L"control") return Event::CONTROL;
else if (name == L"sysex") return Event::SYSEX;
else if (name == L"connect") return Event::CONNECT;
else if (name == L"disconnect") return Event::DISCONNECT;
else return Event::UNKNOWN;
}
Event event = Event::UNKNOWN;
relpipe::common::type::Integer time;
relpipe::common::type::Integer channel;
relpipe::common::type::Boolean noteOn;
relpipe::common::type::Integer notePitch;
relpipe::common::type::Integer noteVelocity;
relpipe::common::type::Integer controllerId;
relpipe::common::type::Integer controllerValue;
relpipe::common::type::StringX raw;
relpipe::common::type::StringX connectionSourcePort;
relpipe::common::type::StringX connectionDestinationPort;
size_t attributeIndex = 0;
} recordContext;
} relationContext;
static void jackErrorCallback(const char * message) {
std::wstring_convert < std::codecvt_utf8<wchar_t>> convertor; // TODO: local system encoding
std::wcerr << L"JACK: " << convertor.from_bytes(message) << std::endl;
}
void finalize() {
// Close JACK connection:
jack_deactivate(realTimeContext.jackClient);
jack_client_close(realTimeContext.jackClient);
jack_ringbuffer_free(realTimeContext.ringBuffer);
pthread_mutex_unlock(&realTimeContext.processingLock);
}
void failInConstructor(const relpipe::common::type::StringX& errorMessage) {
finalize();
throw JackException(errorMessage);
}
/**
* Wait for the signal that is emitted at the end of the real-time processCallback() cycle.
*/
void waitForRTCycle() {
pthread_cond_wait(&realTimeContext.processingDone, &realTimeContext.processingLock);
}
public:
JackHandler(Configuration& configuration) : configuration(configuration) {
pthread_mutex_lock(&realTimeContext.processingLock);
// Initialize JACK connection:
std::string clientName = convertor.to_bytes(configuration.client);
realTimeContext.jackClient = jack_client_open(clientName.c_str(), JackNullOption, nullptr);
if (realTimeContext.jackClient == nullptr) failInConstructor(L"Could not create JACK client.");
realTimeContext.ringBuffer = jack_ringbuffer_create(realTimeContext.RING_BUFFER_SIZE * sizeof (MidiMessage));
jack_set_process_callback(realTimeContext.jackClient, RealTimeContext::processCallback, &realTimeContext);
jack_set_sync_callback(realTimeContext.jackClient, RealTimeContext::syncCallback, &realTimeContext);
// TODO: report also other events (connections etc.)
jack_set_error_function(jackErrorCallback);
jack_set_info_function(jackErrorCallback);
realTimeContext.jackPort = jack_port_register(realTimeContext.jackClient, convertor.to_bytes(configuration.port).c_str(), JACK_DEFAULT_MIDI_TYPE, JackPortIsOutput, 0);
if (realTimeContext.jackPort == nullptr) failInConstructor(L"Could not register the JACK port.");
if (mlockall(MCL_CURRENT | MCL_FUTURE)) fwprintf(stderr, L"Warning: Can not lock memory.\n");
int jackError = jack_activate(realTimeContext.jackClient);
if (jackError) failInConstructor(L"Could not activate the JACK client.");
// Connect to configured destination ports:
const char* jackPortName = jack_port_name(realTimeContext.jackPort);
for (auto destinationPort : configuration.connectTo) {
int error = jack_connect(realTimeContext.jackClient, jackPortName, convertor.to_bytes(destinationPort).c_str());
if (error) failInConstructor(L"Connection to the JACK port failed: " + destinationPort);
}
// Wait for a port connection, because it does not make much sense to send MIDI events nowhere:
while (jack_port_connected(realTimeContext.jackPort) < configuration.requiredConnections) usleep(10000);
}
void startRelation(const relpipe::common::type::StringX name, std::vector<relpipe::reader::handlers::AttributeMetadata> attributes) override {
relationContext = RelationContext();
relationContext.attributes = attributes;
// TODO: configurable relation name
if (!relationContext.hasAttribute(L"event")) {
relationContext.skip = true;
fwprintf(stderr, L"Relation „%ls“ will be ignored because mandatory attribute „event“ is missing.\n", name.c_str());
}
}
void attribute(const relpipe::common::type::StringX& value) override {
if (relationContext.skip) return;
// TODO: switch to RelationalReaderValueHandler
RelationContext& rel = relationContext;
RelationContext::RecordContext& rec = rel.recordContext;
const auto attributeName = rel.attributes[rec.attributeIndex].getAttributeName();
if (attributeName == L"event") rec.event = rec.parseEventType(value);
else if (attributeName == L"time") rec.time = std::stoll(value);
else if (attributeName == L"channel") rec.channel = std::stoi(value);
else if (attributeName == L"controller_id") rec.controllerId = std::stoi(value);
else if (attributeName == L"controller_value") rec.controllerValue = std::stoi(value);
else if (attributeName == L"note_on") rec.noteOn = value == L"true";
else if (attributeName == L"note_pitch") rec.notePitch = std::stoi(value);
else if (attributeName == L"note_velocity") rec.noteVelocity = std::stoi(value);
else if (attributeName == L"raw") rec.raw = value;
else if (attributeName == L"source_port") rec.connectionSourcePort = value;
else if (attributeName == L"destination_port") rec.connectionDestinationPort = value;
rec.attributeIndex++;
if (rec.attributeIndex == rel.attributes.size()) {
while (continueProcessing && jack_ringbuffer_write_space(realTimeContext.ringBuffer) < sizeof (MidiMessage)) waitForRTCycle(); // wait, if we are faster than the real-time thread
if (!continueProcessing) return;
MidiMessage m;
m.time = rec.time;
m.size = 0;
if (rec.event == RelationContext::RecordContext::Event::NOTE) {
m.size = 3;
m.buffer[0] = (rec.noteOn ? 0x90 : 0x80) | rec.channel;
m.buffer[1] = rec.notePitch;
m.buffer[2] = rec.noteVelocity;
} else if (rec.event == RelationContext::RecordContext::Event::CONTROL) {
m.size = 3;
m.buffer[0] = 0xB0 | rec.channel;
m.buffer[1] = rec.controllerId;
m.buffer[2] = rec.controllerValue;
} else if (rec.event == RelationContext::RecordContext::Event::CONNECT) {
int result = jack_connect(realTimeContext.jackClient, convertor.to_bytes(rec.connectionSourcePort).c_str(), convertor.to_bytes(rec.connectionDestinationPort).c_str());
if (result != 0 && result != EEXIST) std::wcerr << L"Unable to connect: „" << rec.connectionSourcePort << L"“ to: „" << rec.connectionDestinationPort << L"“." << std::endl;
} else if (rec.event == RelationContext::RecordContext::Event::DISCONNECT) {
int result = jack_disconnect(realTimeContext.jackClient, convertor.to_bytes(rec.connectionSourcePort).c_str(), convertor.to_bytes(rec.connectionDestinationPort).c_str());
if (result != 0) std::wcerr << L"Unable to disconnect: „" << rec.connectionSourcePort << L"“ from: „" << rec.connectionDestinationPort << L"“." << std::endl;
} else { // SysEx and other raw messages
size_t nibble = 0;
for (int i = 0; i < rec.raw.size() && m.size < sizeof (m.buffer); i++) {
wchar_t ch = rec.raw[i];
if (ch == L' ') continue;
else if (ch >= L'0' && ch <= L'9') m.buffer[m.size] += (ch - '0') /**/ << (nibble % 2 ? 0 : 4);
else if (ch >= L'a' && ch <= L'f') m.buffer[m.size] += (ch - 'a' + 10) << (nibble % 2 ? 0 : 4);
else if (ch >= L'A' && ch <= L'F') m.buffer[m.size] += (ch - 'A' + 10) << (nibble % 2 ? 0 : 4);
else throw JackException(L"Invalid character in the hexadeximal sequence: „" + std::wstring(1, ch) + L"“.");
nibble++;
if (nibble % 2 == 0) m.size++;
}
}
if (m.size > 0) jack_ringbuffer_write(realTimeContext.ringBuffer, (const char *) &m, sizeof (m));
relationContext.recordContext = RelationContext::RecordContext();
}
}
void endOfPipe() {
// TODO: optionally mute all; probably enabled by default
// Wait until the ring buffer is empty (messages dequeued from the buffer) and real-time cycle was finished (messages passed to JACK)
while (continueProcessing && jack_ringbuffer_read_space(realTimeContext.ringBuffer)) pthread_cond_wait(&realTimeContext.processingDone, &realTimeContext.processingLock);
// There might be a (rare) race condition.
// Between jack_ringbuffer_read_space() and pthread_cond_wait() the real-time thread might finish the cycle and we will miss the pthread_cond_signal()
// and will sleep until the next cycle. In endOfPipe() it is not a big problem.
// But missing the cycle in attribute() might be worse.
// However it should not happen due to the buffer size
// and amount of work done in the real-time thread (message copying) vs. amount of work done between the jack_ringbuffer_write_space() and pthread_cond_wait() calls (nothing).
}
void finish(int sig) {
continueProcessing = false;
}
virtual ~JackHandler() {
finalize();
}
};
}
}
}