/**
* DJM-Fix
* 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/>.
*/
#include <iostream>
#include <iomanip>
#include <sstream>
#include <stdexcept>
#include <thread>
#include <mutex>
#include <atomic>
#include <regex>
#include <alsa/asoundlib.h>
#include "AlsaBridge.h"
#include "Logger.h"
namespace djmfix {
namespace alsa {
using L = djmfix::logging::Level;
class AlsaBridgeImpl : public AlsaBridge, private djmfix::MidiSender {
private:
djmfix::DJMFix* djmFix;
djmfix::logging::Logger* logger;
snd_rawmidi_t* input;
snd_rawmidi_t* output;
std::thread receivingThread;
std::recursive_mutex midiMutex;
std::atomic<bool> stopped{false};
std::string findDeviceName(std::regex cardNamePattern) {
std::vector<int> cardNumbers;
logger->log(L::INFO, "Looking for available cards:");
for (int card = -1; snd_card_next(&card) == 0 && card >= 0;) {
char* longName = nullptr;
snd_card_get_longname(card, &longName);
std::stringstream logMessage;
logMessage << " - card: #" << card << ": '" << longName << "'";
if (std::regex_match(longName, cardNamePattern)) {
cardNumbers.push_back(card);
logMessage << " [matches]";
}
logger->log(L::INFO, logMessage.str());
free(longName);
}
if (cardNumbers.size() == 1) {
logger->log(L::INFO, "Going to fix card #" + std::to_string(cardNumbers[0]));
return "hw:" + std::to_string(cardNumbers[0]);
} else if (cardNumbers.empty()) {
throw std::invalid_argument("No card with matching name found. Is the card connected? Maybe try to provide different name pattern.");
} else {
throw std::invalid_argument("Multiple cards with matching name found. Please provide a name pattern that matches only one card");
}
}
std::string toString(const MidiMessage& midiMessage) {
std::stringstream result;
for (uint8_t b : midiMessage) result << std::hex << std::setw(2) << std::setfill('0') << (int) b;
return result.str();
}
void run() {
while (!stopped) {
{
std::lock_guard<std::recursive_mutex> lock(midiMutex);
// TODO: poll
uint8_t buffer[256];
ssize_t length = snd_rawmidi_read(input, buffer, sizeof (buffer));
if (length > 0 && length <= sizeof (buffer)) {
// TODO: multiple messages combined together?
djmFix->receive(MidiMessage(buffer, buffer + length));
}
}
std::this_thread::sleep_for(std::chrono::milliseconds(100));
}
}
public:
AlsaBridgeImpl(djmfix::DJMFix* djmFix, const std::string& cardNamePattern, djmfix::logging::Logger* logger) : djmFix(djmFix), logger(logger ? logger : djmfix::logging::blackhole()) {
if (djmFix == nullptr) throw std::invalid_argument("Need a djmFix for AlsaBridge.");
std::string deviceName = findDeviceName(std::regex(cardNamePattern));
int error = snd_rawmidi_open(&input, &output, deviceName.c_str(), SND_RAWMIDI_NONBLOCK);
if (error) throw std::invalid_argument("Unable to open ALSA device.");
djmFix->setMidiSender(this);
}
virtual ~AlsaBridgeImpl() {
// TODO: do not use raw/exclusive access to the MIDI device
snd_rawmidi_close(input);
snd_rawmidi_close(output);
logger->log(L::FINER, "~AlsaBridgeImpl()");
}
virtual void start() override {
djmFix->start();
receivingThread = std::thread(&AlsaBridgeImpl::run, this);
}
virtual void stop() override {
stopped = true;
receivingThread.join();
djmFix->stop();
}
virtual void send(MidiMessage midiMessage) override {
std::lock_guard<std::recursive_mutex> lock(midiMutex);
ssize_t length = snd_rawmidi_write(output, midiMessage.data(), midiMessage.size());
logger->log(L::FINE, "Sent message: length = " + std::to_string(length) + " data = " + toString(midiMessage));
}
};
AlsaBridge* create(djmfix::DJMFix* djmFix, const std::string& deviceName, djmfix::logging::Logger* logger) {
return new AlsaBridgeImpl(djmFix, deviceName, logger);
}
}
}