juplo.de Git - demos/kafka/chat/blob - src/main/java/de/juplo/kafka/chat/backend/implementation/inmemory/SimpleChatHomeService.java

   1 package de.juplo.kafka.chat.backend.implementation.inmemory;
   2
   3 import de.juplo.kafka.chat.backend.domain.*;
   4 import de.juplo.kafka.chat.backend.domain.exceptions.UnknownChatroomException;
   5 import de.juplo.kafka.chat.backend.implementation.StorageStrategy;
   6 import lombok.extern.slf4j.Slf4j;
   7 import reactor.core.publisher.Flux;
   8 import reactor.core.publisher.Mono;
   9
  10 import java.time.Clock;
  11 import java.util.*;
  12
  13
  14 @Slf4j
  15 public class SimpleChatHomeService implements ChatHomeService
  16 {
  17   private final Integer shard;
  18   private final Map<UUID, ChatRoomInfo> chatRoomInfo;
  19   private final Map<UUID, ChatRoomData> chatRoomData;
  20   private final Clock clock;
  21   private final int bufferSize;
  22
  23
  24
  25   public SimpleChatHomeService(
  26       Clock clock,
  27       int bufferSize)
  28   {
  29     this(
  30         null,
  31         clock,
  32         bufferSize);
  33   }
  34
  35   public SimpleChatHomeService(
  36       Integer shard,
  37       Clock clock,
  38       int bufferSize)
  39   {
  40     log.debug("Creating SimpleChatHomeService");
  41
  42     this.shard = shard;
  43     this.chatRoomInfo = new HashMap<>();
  44     this.chatRoomData = new HashMap<>();
  45     this.clock = clock;
  46     this.bufferSize = bufferSize;
  47   }
  48
  49
  50   Mono<Void> restore(StorageStrategy storageStrategy)
  51   {
  52     return storageStrategy
  53         .readChatRoomInfo()
  54         .filter(info ->
  55         {
  56           if (shard == null || info.getShard() == shard)
  57           {
  58             return true;
  59           }
  60           else
  61           {
  62             log.info(
  63                 "SimpleChatHome for shard {} ignores not owned chat-room {}",
  64                 shard,
  65                 info);
  66             return false;
  67           }
  68         })
  69         .flatMap(info ->
  70         {
  71           UUID chatRoomId = info.getId();
  72           InMemoryChatMessageService chatMessageService =
  73               new InMemoryChatMessageService(chatRoomId);
  74
  75           chatRoomInfo.put(chatRoomId, info);
  76           chatRoomData.put(
  77               info.getId(),
  78               new ChatRoomData(
  79                   clock,
  80                   chatMessageService,
  81                   bufferSize));
  82
  83           return chatMessageService.restore(storageStrategy);
  84         })
  85         .then()
  86         .doOnSuccess(empty -> log.info("Restored {}", this))
  87         .doOnError(throwable -> log.error("Could not restore {}", this));
  88   }
  89
  90
  91   @Override
  92   public Mono<ChatRoomInfo> createChatRoom(UUID id, String name)
  93   {
  94     log.info("Creating ChatRoom with buffer-size {}", bufferSize);
  95     ChatMessageService service = new InMemoryChatMessageService(id);
  96     ChatRoomInfo chatRoomInfo = new ChatRoomInfo(id, name, shard);
  97     this.chatRoomInfo.put(id, chatRoomInfo);
  98     ChatRoomData chatRoomData = new ChatRoomData(clock, service, bufferSize);
  99     this.chatRoomData.put(id, chatRoomData);
 100     return Mono.just(chatRoomInfo);
 101   }
 102
 103   @Override
 104   public Mono<ChatRoomInfo> getChatRoomInfo(UUID id)
 105   {
 106     return Mono
 107         .justOrEmpty(chatRoomInfo.get(id))
 108         .switchIfEmpty(Mono.error(() -> new UnknownChatroomException(id)));
 109   }
 110
 111   @Override
 112   public Flux<ChatRoomInfo> getChatRoomInfo()
 113   {
 114     return Flux.fromIterable(chatRoomInfo.values());
 115   }
 116
 117   @Override
 118   public Mono<ChatRoomData> getChatRoomData(UUID id)
 119   {
 120     return Mono
 121         .justOrEmpty(chatRoomData.get(id))
 122         .switchIfEmpty(Mono.error(() -> new UnknownChatroomException(id)));
 123   }
 124
 125   @Override
 126   public Mono<String[]> getShardOwners()
 127   {
 128     return Mono.empty();
 129   }
 130
 131   @Override
 132   public String toString()
 133   {
 134     return SimpleChatHomeService.class.getSimpleName() + ", shard=" + shard;
 135   }
 136 }