enum opcode {
	CREATE = 1;
	DELETE = 2;
	READ   = 3;
	WRITE  = 4;
	START  = 5;
	STOP   = 6;
	REPLY  = 7;
}

message cdap {
	required opcode opcode    = 1;
	required uint32 invoke_id = 2;
	optional uint32 flags     = 3;
	optional string name      = 4;
	repeated bytes value      = 5;
	optional int32 result     = 6;
}