X-Git-Url: https://juplo.de/gitweb/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fde%2Fjuplo%2Fkafka%2Fchat%2Fbackend%2Fpersistence%2Fkafka%2FKafkaChatHomeService.java;h=4460432254379ca6ca0a420db8e4d795f03aa4d7;hb=394aa7848abcfc7b4510cd2688c00fce01b3c225;hp=7ebf0493056ae19450cbb3496821cc5a9c8d6a18;hpb=f14af7787fd519cffcdcd83cd375fb7477b4ced2;p=demos%2Fkafka%2Fchat

diff --git a/src/main/java/de/juplo/kafka/chat/backend/persistence/kafka/KafkaChatHomeService.java b/src/main/java/de/juplo/kafka/chat/backend/persistence/kafka/KafkaChatHomeService.java
index 7ebf0493..44604322 100644
--- a/src/main/java/de/juplo/kafka/chat/backend/persistence/kafka/KafkaChatHomeService.java
+++ b/src/main/java/de/juplo/kafka/chat/backend/persistence/kafka/KafkaChatHomeService.java
@@ -2,31 +2,47 @@ package de.juplo.kafka.chat.backend.persistence.kafka;
 
 import de.juplo.kafka.chat.backend.domain.ChatHomeService;
 import de.juplo.kafka.chat.backend.domain.ChatRoom;
+import de.juplo.kafka.chat.backend.domain.ShardNotOwnedException;
 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.producer.Producer;
 import org.apache.kafka.common.TopicPartition;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
+import java.time.Duration;
 import java.time.ZoneId;
 import java.util.*;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 
 @Slf4j
-public class KafkaChatHomeService implements ChatHomeService, ConsumerRebalanceListener
+public class KafkaChatHomeService implements ChatHomeService, Runnable, ConsumerRebalanceListener
 {
+  private final ExecutorService executorService;
   private final Consumer<String, MessageTo> consumer;
   private final Producer<String, MessageTo> producer;
   private final String topic;
   private final ZoneId zoneId;
   // private final long[] offsets; Erst mal immer alles neu einlesen
-  private final ChatHomeLoader[] chatHomeLoaders;
+  private final boolean[] isShardOwned;
   private final Map<UUID, ChatRoom>[] chatRoomMaps;
+  private final ReadWriteLock lock = new ReentrantReadWriteLock();
+
+  private boolean running;
 
 
   public KafkaChatHomeService(
+    ExecutorService executorService,
     Consumer<String, MessageTo> consumer,
     Producer<String, MessageTo> producer,
     String topic,
@@ -34,6 +50,7 @@ public class KafkaChatHomeService implements ChatHomeService, ConsumerRebalanceL
     int numShards)
   {
     log.debug("Creating KafkaChatHomeService");
+    this.executorService = executorService;
     this.consumer = consumer;
     this.producer = producer;
     this.topic = topic;
@@ -43,7 +60,7 @@ public class KafkaChatHomeService implements ChatHomeService, ConsumerRebalanceL
     // {
     //   this.offsets[i] = 0l;
     // }
-    this.chatHomeLoaders = new ChatHomeLoader[numShards];
+    this.isShardOwned = new boolean[numShards];
     this.chatRoomMaps = new Map[numShards];
   }
 
@@ -51,47 +68,52 @@ public class KafkaChatHomeService implements ChatHomeService, ConsumerRebalanceL
   @Override
   public void onPartitionsAssigned(Collection<TopicPartition> partitions)
   {
-    consumer.endOffsets(partitions).forEach((topicPartition, currentOffset) ->
+    try
     {
-      if (!topicPartition.topic().equals(topic))
+      lock.writeLock().lock();
+
+      consumer.endOffsets(partitions).forEach((topicPartition, currentOffset) ->
       {
-        log.warn("Ignoring partition from unwanted topic: {}", topicPartition);
-        return;
-      }
+        if (!topicPartition.topic().equals(topic))
+        {
+          log.warn("Ignoring partition from unwanted topic: {}", topicPartition);
+          return;
+        }
 
-      int partition = topicPartition.partition();
-      long unseenOffset = 0; // offsets[partition];
-
-      log.info(
-          "Loading messages from partition {}: start-offset={} -> current-offset={}",
-          partition,
-          unseenOffset,
-          currentOffset);
-
-      // TODO: reuse! Nicht immer alles neu laden, sondern erst ab offsets[partition]!
-      consumer.seek(topicPartition, unseenOffset);
-      chatHomeLoaders[partition] = new ChatHomeLoader(
-          producer,
-          currentOffset,
-          zoneId);
-    });
+        int partition = topicPartition.partition();
+        long unseenOffset = 0; // offsets[partition];
+
+        log.info(
+            "Loading messages from partition {}: start-offset={} -> current-offset={}",
+            partition,
+            unseenOffset,
+            currentOffset);
+
+        // TODO: reuse! Nicht immer alles neu laden, sondern erst ab offsets[partition]!
+        consumer.seek(topicPartition, unseenOffset);
+      });
+
+      consumer.resume(partitions);
+    }
+    finally
+    {
+      lock.writeLock().unlock();
+    }
   }
 
   @Override
   public void onPartitionsRevoked(Collection<TopicPartition> partitions)
   {
-    partitions.forEach(tp ->
+    partitions.forEach(topicPartition ->
     {
-      if (!tp.topic().equals(topic))
+      if (!topicPartition.topic().equals(topic))
       {
-        log.warn("Ignoring partition from unwanted topic: {}", tp);
+        log.warn("Ignoring partition from unwanted topic: {}", topicPartition);
         return;
       }
 
-      int partition = tp.partition();
-      long unseenOffset = offsets[partition];
-
-      log.info("Reading partition {} from {} -> {}", partition, unseenOffset, currentOffset);
+      int partition = topicPartition.partition();
+      // long unseenOffset = offsets[partition]; TODO: Offset merken...?
     });
     log.info("Revoked partitions: {}", partitions);
   }
@@ -99,56 +121,69 @@ public class KafkaChatHomeService implements ChatHomeService, ConsumerRebalanceL
   @Override
   public void onPartitionsLost(Collection<TopicPartition> partitions)
   {
-    log.info("Revoked partitions: {}", partitions);
+    // TODO: Muss auf den Verlust anders reagiert werden?
+    onPartitionsRevoked(partitions);
   }
 
-  private void foo()
+  @Override
+  public void run()
   {
-    Set<Integer> owned = Arrays
-      .stream(ownedShards)
-      .collect(
-        () -> new HashSet<>(),
-        (set, i) -> set.add(i),
-        (a, b) -> a.addAll(b));
-    for (int shard = 0; shard < numShards; shard++)
+    consumer.subscribe(List.of(topic));
+
+    running = true;
+
+    try
     {
-      chatRoomMaps[shard] = owned.contains(shard)
-        ? new HashMap<>()
-        : null;
-    }
-    chatroomFlux
-      .filter(chatRoom ->
+      while (running)
       {
-        if (owned.contains(chatRoom.getShard()))
-        {
-          return true;
-        }
-        else
+        ConsumerRecords<String, MessageTo> records = consumer.poll(Duration.ofMinutes(5));
+        log.info("Fetched {} messages", records.count());
+
+        for (ConsumerRecord<String, MessageTo> record : records)
         {
-          log.info("Ignoring not owned chat-room {}", chatRoom);
-          return false;
-        }
-      })
-      .toStream()
-      .forEach(chatroom -> chatRoomMaps[chatroom.getShard()].put(chatroom.getId(), chatroom));
-  }
 
-  @Override
-  public Mono<ChatRoom> putChatRoom(ChatRoom chatRoom)
-  {
-    chatRoomMaps[chatRoom.getShard()].put(chatRoom.getId(), chatRoom);
-    return Mono.just(chatRoom);
+        }
+      }
+    }
   }
 
   @Override
   public Mono<ChatRoom> getChatRoom(int shard, UUID id)
   {
-    return Mono.justOrEmpty(chatRoomMaps[shard].get(id));
+    if (lock.readLock().tryLock())
+    {
+      try
+      {
+        return Mono.justOrEmpty(chatRoomMaps[shard].get(id));
+      }
+      finally
+      {
+        lock.readLock().unlock();
+      }
+    }
+    else
+    {
+      throw new ShardNotOwnedException(shard);
+    }
   }
 
   @Override
   public Flux<ChatRoom> getChatRooms(int shard)
   {
-    return Flux.fromStream(chatRoomMaps[shard].values().stream());
+    if (lock.readLock().tryLock())
+    {
+      try
+      {
+        return Flux.fromStream(chatRoomMaps[shard].values().stream());
+      }
+      finally
+      {
+        lock.readLock().unlock();
+      }
+    }
+    else
+    {
+      throw new ShardNotOwnedException(shard);
+    }
   }
 }