refactor: Introduced `ChannelMediator`

[demos/kafka/chat] / src / main / java / de / juplo / kafka / chat / backend / implementation / kafka / DataChannel.java

diff --git a/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/DataChannel.java b/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/DataChannel.java
index 2c3e60a..64117f5 100644 (file)
--- a/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/DataChannel.java
+++ b/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/DataChannel.java
@@ -7,10 +7,7 @@ import de.juplo.kafka.chat.backend.implementation.kafka.messages.AbstractMessage
 import de.juplo.kafka.chat.backend.implementation.kafka.messages.data.EventChatMessageReceivedTo;
 import lombok.Getter;
 import lombok.extern.slf4j.Slf4j;
-import org.apache.kafka.clients.consumer.Consumer;
-import org.apache.kafka.clients.consumer.ConsumerRebalanceListener;
-import org.apache.kafka.clients.consumer.ConsumerRecord;
-import org.apache.kafka.clients.consumer.ConsumerRecords;
+import org.apache.kafka.clients.consumer.*;
 import org.apache.kafka.clients.producer.Producer;
 import org.apache.kafka.clients.producer.ProducerRecord;
 import org.apache.kafka.common.TopicPartition;
@@ -31,13 +28,14 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
   private final Consumer<String, AbstractMessageTo> consumer;
   private final ZoneId zoneId;
   private final int numShards;
+  private final Duration pollingInterval;
   private final int bufferSize;
   private final Clock clock;
   private final boolean[] isShardOwned;
   private final long[] currentOffset;
   private final long[] nextOffset;
   private final Map<UUID, ChatRoomData>[] chatRoomData;
-  private final InfoChannel infoChannel;
+  private final ChannelMediator channelMediator;
   private final ShardingPublisherStrategy shardingPublisherStrategy;
 
   private boolean running;
@@ -52,9 +50,10 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
     Consumer<String, AbstractMessageTo> dataChannelConsumer,
     ZoneId zoneId,
     int numShards,
+    Duration pollingInterval,
     int bufferSize,
     Clock clock,
-    InfoChannel infoChannel,
+    ChannelMediator channelMediator,
     ShardingPublisherStrategy shardingPublisherStrategy)
   {
     log.debug(
@@ -68,6 +67,7 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
     this.producer = producer;
     this.zoneId = zoneId;
     this.numShards = numShards;
+    this.pollingInterval = pollingInterval;
     this.bufferSize = bufferSize;
     this.clock = clock;
     this.isShardOwned = new boolean[numShards];
@@ -77,7 +77,7 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
     IntStream
         .range(0, numShards)
         .forEach(shard -> this.chatRoomData[shard] = new HashMap<>());
-    this.infoChannel = infoChannel;
+    this.channelMediator = channelMediator;
     this.shardingPublisherStrategy = shardingPublisherStrategy;
   }
 
@@ -144,7 +144,7 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
           currentOffset);
 
       consumer.seek(topicPartition, nextOffset[partition]);
-      infoChannel.sendShardAssignedEvent(partition);
+      channelMediator.shardAssigned(partition);
       shardingPublisherStrategy
           .publishOwnership(partition)
           .doOnSuccess(instanceId -> log.info(
@@ -155,7 +155,8 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
               "Could not publish instance {} as owner of shard {}: {}",
               instanceId,
               partition,
-              throwable))
+              throwable.toString()))
+          .onErrorComplete()
           .block();
     });
 
@@ -171,7 +172,7 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
       isShardOwned[partition] = false;
       nextOffset[partition] = consumer.position(topicPartition);
       log.info("Partition revoked: {} - next={}", partition, nextOffset[partition]);
-      infoChannel.sendShardRevokedEvent(partition);
+      channelMediator.shardRevoked(partition);
     });
   }
 
@@ -192,7 +193,7 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
     {
       try
       {
-        ConsumerRecords<String, AbstractMessageTo> records = consumer.poll(Duration.ofMinutes(1));
+        ConsumerRecords<String, AbstractMessageTo> records = consumer.poll(pollingInterval);
         log.info("Fetched {} messages", records.count());
 
         if (loadInProgress)
@@ -323,7 +324,7 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
       return Mono.error(new ShardNotOwnedException(instanceId, shard));
     }
 
-    return infoChannel
+    return channelMediator
         .getChatRoomInfo(id)
         .map(chatRoomInfo ->
             chatRoomData[shard].computeIfAbsent(id, this::computeChatRoomData));
@@ -335,4 +336,9 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
     KafkaChatMessageService service = new KafkaChatMessageService(this, chatRoomId);
     return new ChatRoomData(clock, service, bufferSize);
   }
+
+  ConsumerGroupMetadata getConsumerGroupMetadata()
+  {
+    return consumer.groupMetadata();
+  }
 }