can send ess streaming data types flatbuffer messages via kafka

src/asynStreamGeneratorDriver.cpp

@@ -1,4 +1,5 @@
 #include "asynOctetSyncIO.h"
+#include "ev42_events_generated.h"
 #include <cstring>
 #include <epicsStdio.h>
 #include <iocsh.h>
@@ -140,14 +141,24 @@ asynStreamGeneratorDriver::asynStreamGeneratorDriver(const char *portName,
     }
 
     char *msg = "asdf\n";
+    // EventMessageBuilder b;
+    //  We could I believe reuse a buffer which might be more performant.
+    flatbuffers::FlatBufferBuilder builder(1024);
+    std::vector<uint32_t> tof = {1, 2, 3};
+    std::vector<uint32_t> did = {0, 0, 0};
+    auto message =
+        CreateEventMessageDirect(builder, "monitor1", 0, 0, &tof, &did);
 
-    rd_kafka_resp_err_t err =
-        rd_kafka_producev(producer, RD_KAFKA_V_TOPIC("NEWEFU_TEST"),
-                          RD_KAFKA_V_MSGFLAGS(RD_KAFKA_MSG_F_COPY),
-                          // RD_KAFKA_V_KEY((void *)key, key_len),
-                          RD_KAFKA_V_VALUE((void *)msg, 6),
-                          // RD_KAFKA_V_OPAQUE(NULL),
-                          RD_KAFKA_V_END);
+    builder.Finish(message, "ev42");
+    printf("buffer size: %d\n", builder.GetSize());
+
+    rd_kafka_resp_err_t err = rd_kafka_producev(
+        producer, RD_KAFKA_V_TOPIC("NEWEFU_TEST"),
+        RD_KAFKA_V_MSGFLAGS(RD_KAFKA_MSG_F_COPY),
+        // RD_KAFKA_V_KEY((void *)key, key_len),
+        RD_KAFKA_V_VALUE((void *)builder.GetBufferPointer(), builder.GetSize()),
+        // RD_KAFKA_V_OPAQUE(NULL),
+        RD_KAFKA_V_END);
 
     if (err) {
         // TODO