User-defined operation types are supported when rb is full

[RanMaoyi]

Support four ops when ring bus is full

 0 RB_FULL_NONE,       // do nothing, and return enqueue failed                                                                                                                                                         
 1 RB_FULL_DROP,        // drop all msgs in ring bus, and enqueue new msg                                                                                                                                                        
 2 RB_FULL_RETURN,   // Get and clean up all msgs from ring bus and return in aio                                                                                                                                                            
 3 RB_FULL_FILE,          // Get and clean up all msgs from ring bus and write them to file

User can specify which type of operation to use like

exchange_client.name {
     exchange {
         topic = "topic1",
         name = "exchange1",
         ringbus = {
             name = "ringbuffer1",
             cap = 100,
             #  0: RB_FULL_NONE
             #  1: RB_FULL_DROP
             #  2: RB_FULL_RETURN
             #  3: RB_FULL_FILE
             fullOp = 3
         }
     }
}

TODO: Parquet part is not supported now

[JaylinYu]

I guess this is your first step to implement MQTT Stream?

But not all MQ need a ringbus

[JaylinYu]

need to fix the warnings @RanMaoyi

[wanghaEMQ]

cool