/**
* Relational pipes
* Copyright © 2022 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 <mqueue.h>
#include <string>
#include <stdexcept>
#include <cstring>
namespace relpipe {
namespace out {
namespace zeromq {
class ZeroMQ {
private:
const static size_t MSG_SIZE = 8192; // TODO: configurable/dynamic
std::string queueName;
mqd_t handle = -2;
bool unlinkOnClose = false;
ZeroMQ(std::string queueName, mqd_t handle, bool unlinkOnClose) : queueName(queueName), handle(handle), unlinkOnClose(unlinkOnClose) {
}
public:
virtual ~ZeroMQ() {
if (handle >= 0) mq_close(handle);
if (unlinkOnClose) mq_unlink(queueName.c_str());
}
static ZeroMQ* open(std::string queueName, bool unlinkOnClose = false) {
mqd_t handle = mq_open(queueName.c_str(), O_RDWR | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
if (handle >= 0) return new ZeroMQ(queueName, handle, unlinkOnClose);
else throw std::logic_error("Unable to open ZeroMQ: " + queueName + " error: " + strerror(errno));
}
void send(std::string message) {
int result = mq_send(handle, message.c_str(), message.size(), 0);
if (result) throw std::logic_error("Unable to send message to" + queueName + " error: " + strerror(errno));
}
std::string receive() {
char buffer[MSG_SIZE + 1];
memset(buffer, 0, MSG_SIZE + 1);
ssize_t msgSize = mq_receive(handle, buffer, MSG_SIZE, nullptr);
if (msgSize > sizeof (buffer))throw std::logic_error("Invalid ZeroMQ message size.");
else if (msgSize >= 0) return std::string(buffer, msgSize);
else throw std::logic_error("Unable to receive ZeroMQ message from " + queueName + " error: " + strerror(errno));
}
};
}
}
}