show/explain meta info better. ref KxSystems#105

running test_consumer.q, test_producer.q now presents meta info better
test_consumer.q also now prevented from producing erroneous UNKNOWN_TOPIC_OR_PART msg

docs/reference.md

@@ -72,7 +72,14 @@ _Information about configuration of brokers and topics_
 .kfk.Metadata id
 ```
 
-Where `id` is a consumer or producer ID, returns a dictionary with information about the brokers and topics.
+Where `id` is a consumer or producer ID, returns a dictionary populated with the following info:
+
+-   `orig_broker_id` (int): Broker originating this metadata
+-   `orig_broker_name` (symbol): Name of originating broker
+-   `brokers` (list of dictionaries): Info on current brokers
+-   `topics` (list of dictionaries): Info on current topics
+
+e.g.
 
 ```q
 q)show producer_meta:.kfk.Metadata producer

examples/test_consumer.q

@@ -9,24 +9,36 @@ kfk_cfg:(!) . flip(
 client:.kfk.Consumer[kfk_cfg];
 
 // Topics to subscribe to
-topic1:`test1; topic2:`test2;
+topic1:`test1;
+topic2:`test2;
 
-// Define datasets and topic callbacks for individual
-// topic subscriptions `topic1 and `topic2
+// Define datasets and topic callbacks for topic1
 data1:();
 topcb1:{[msg]
   msg[`data]:"c"$msg[`data];
   msg[`rcvtime]:.z.p;
   data1,::enlist msg;}
 
+// Define datasets and topic callbacks for topic2
 data2:();
 topcb2:{[msg]
   msg[`data]:"c"$msg[`data];
   msg[`rcvtime]:.z.t;
   data2,::enlist msg;}
 
+printmeta:{
+  -1 "==== MetaData provided by the following broker =======";
+  -1 "name:",string x`orig_broker_name;
+  -1 "id:",string x`orig_broker_id;
+  -1 "==== Brokers =========================================";
+  show each x`brokers;
+  -1 "==== Topics ==========================================";
+  $[count x`topics;show each x`topics;-1 "[None]"];
+  -1 "";}
+
+printmeta .kfk.Metadata[client];
+
 // Subscribe to topic1 and topic2 with different callbacks from a single client
+-1 "Subscribing to topics called ",(string topic1)," and ",string topic2;
+-1 "Consumed data will be placed in tables data1 and data2 when available (type 'data1' or 'data2' to view)";
 .kfk.Subscribe[client;(topic1;topic2);enlist .kfk.PARTITION_UA;(topcb1;topcb2)]
-
-client_meta:.kfk.Metadata[client];
-show client_meta`topics;

examples/test_producer.q

@@ -1,4 +1,5 @@
 \l ../kfk.q
+
 kfk_cfg:(!) . flip(
   (`metadata.broker.list;`localhost:9092);
   (`statistics.interval.ms;`10000);
@@ -12,12 +13,19 @@ topic2:.kfk.Topic[producer;`test2;()!()]
 .z.ts:{n+:1;topic:$[n mod 2;topic1;topic2];
        .kfk.Pub[topic;.kfk.PARTITION_UA;string x;""]}
 
+printmeta:{
+  -1 "==== MetaData provided by the following broker =======";
+  -1 "name:",string x`orig_broker_name;
+  -1 "id:",string x`orig_broker_id;
+  -1 "==== Brokers =========================================";
+  show each x`brokers;
+  -1 "==== Topics ==========================================";
+  $[count x`topics;show each x`topics;-1 "[None]"];
+  -1 "";}
 
+printmeta .kfk.Metadata[producer];
 
--1 "Publishing on topics:",string[.kfk.TopicName topic1],", ",string[.kfk.TopicName topic2];
+-1 "Publishing single msg on topics: ",string[.kfk.TopicName topic1],", ",string[.kfk.TopicName topic2];
 .kfk.Pub[;.kfk.PARTITION_UA;string .z.p;""]each(topic1;topic2);
--1 "Published one message for each topic";
-producer_meta:.kfk.Metadata[producer];
-show producer_meta`topics;
--1 "Set timer with \\t 500 to publish a message each second to each topic.";
+-1 "Set timer with \\t 500 to publish a message every 1/2 second to each topic in turn";