diff -r 000000000000 -r e5d547ab0c51 src/ZeroMQ.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/ZeroMQ.h	Sun May 01 18:23:45 2022 +0200
@@ -0,0 +1,70 @@
+/**
+ * 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 in {
+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_RDONLY | 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));
+	}
+
+};
+
+}
+}
+}