JFJochReceiver: Use zero-copy ZeroMQ sending

common/ZMQWrappers.cpp

@@ -76,6 +76,24 @@ void ZMQSocket::Send(zmq_msg_t *msg) {
         throw JFJochException(JFJochExceptionCategory::ZeroMQ, "zmq_msg_send failed");
 }
 
+void zmq_socket_free(void *data, void *hint) {
+    auto s = (std::binary_semaphore *) hint;
+    s->release();
+}
+
+void ZMQSocket::SendZeroCopy(const void *buf, size_t buf_size, std::binary_semaphore *sempahore) {
+    std::unique_lock<std::mutex> ul(m);
+    zmq_msg_t msg;
+    if (zmq_msg_init_data(&msg, const_cast<void *>(buf), buf_size, zmq_socket_free, sempahore) != 0) {
+        sempahore->release();
+        throw JFJochException(JFJochExceptionCategory::ZeroMQ, "zmq_msg_init_data failed");
+    }
+    if (zmq_msg_send(&msg, socket, 0) < 0) {
+        sempahore->release();
+        throw JFJochException(JFJochExceptionCategory::ZeroMQ, "zmq_msg_send failed");
+    }
+}
+
 int64_t ZMQSocket::Receive(bool blocking) {
     std::vector<uint8_t> msg;
     return Receive(msg, blocking, true);