feat: `UnknownChatroomException` records shard and owned shards

[demos/kafka/chat] / src / main / java / de / juplo / kafka / chat / backend / persistence / inmemory / InMemoryChatHomeService.java

diff --git a/src/main/java/de/juplo/kafka/chat/backend/persistence/inmemory/InMemoryChatHomeService.java b/src/main/java/de/juplo/kafka/chat/backend/persistence/inmemory/InMemoryChatHomeService.java
index acfd936..29f1312 100644 (file)
--- a/src/main/java/de/juplo/kafka/chat/backend/persistence/inmemory/InMemoryChatHomeService.java
+++ b/src/main/java/de/juplo/kafka/chat/backend/persistence/inmemory/InMemoryChatHomeService.java
@@ -1,47 +1,74 @@
 package de.juplo.kafka.chat.backend.persistence.inmemory;
 
 import de.juplo.kafka.chat.backend.domain.ChatRoom;
-import de.juplo.kafka.chat.backend.domain.ChatHomeService;
 import lombok.extern.slf4j.Slf4j;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
-import java.util.HashMap;
-import java.util.Map;
-import java.util.UUID;
+import java.util.*;
+import java.util.stream.IntStream;
 
 
 @Slf4j
-public class InMemoryChatHomeService implements ChatHomeService<InMemoryChatRoomService>
+public class InMemoryChatHomeService
 {
   private final Map<UUID, ChatRoom>[] chatrooms;
 
 
-  public InMemoryChatHomeService(int numShards, Flux<ChatRoom> chatroomFlux)
+  public InMemoryChatHomeService(
+      int numShards,
+      int[] ownedShards,
+      Flux<ChatRoom> chatroomFlux)
   {
     log.debug("Creating InMemoryChatHomeService");
     this.chatrooms = new Map[numShards];
+    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++)
-        chatrooms[shard] = new HashMap<>();
+    {
+      chatrooms[shard] = owned.contains(shard)
+          ? new HashMap<>()
+          : null;
+    }
     chatroomFlux
+        .filter(chatRoom ->
+        {
+          if (owned.contains(chatRoom.getShard()))
+          {
+            return true;
+          }
+          else
+          {
+            log.info("Ignoring not owned chat-room {}", chatRoom);
+            return false;
+          }
+        })
         .toStream()
         .forEach(chatroom -> chatrooms[chatroom.getShard()].put(chatroom.getId(), chatroom));
   }
 
-  @Override
-  public Mono<ChatRoom> putChatRoom(ChatRoom chatRoom)
+  public void putChatRoom(ChatRoom chatRoom)
   {
     chatrooms[chatRoom.getShard()].put(chatRoom.getId(), chatRoom);
-    return Mono.just(chatRoom);
   }
 
-  @Override
   public Mono<ChatRoom> getChatRoom(int shard, UUID id)
   {
     return Mono.justOrEmpty(chatrooms[shard].get(id));
   }
 
-  @Override
+  public int[] getOwnedShards()
+  {
+    return IntStream
+        .range(0, chatrooms.length)
+        .filter(i -> chatrooms[i] != null)
+        .toArray();
+  }
+
   public Flux<ChatRoom> getChatRooms(int shard)
   {
     return Flux.fromStream(chatrooms[shard].values().stream());