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 historyLimit;
  22
  23
  24
  25   public SimpleChatHomeService(
  26       Clock clock,
  27       int historyLimit)
  28   {
  29     this(
  30         null,
  31         clock,
  32         historyLimit);
  33   }
  34
  35   public SimpleChatHomeService(
  36       Integer shard,
  37       Clock clock,
  38       int historyLimit)
  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.historyLimit = historyLimit;
  47   }
  48
  49
  50   Mono<Void> restore(StorageStrategy storageStrategy)
  51   {
  52     chatRoomInfo.clear();
  53     chatRoomData.clear();
  54
  55     return storageStrategy
  56         .readChatRoomInfo()
  57         .filter(info ->
  58         {
  59           if (shard == null || info.getShard() == shard)
  60           {
  61             return true;
  62           }
  63           else
  64           {
  65             log.info(
  66                 "SimpleChatHome for shard {} ignores not owned chat-room {}",
  67                 shard,
  68                 info);
  69             return false;
  70           }
  71         })
  72         .flatMap(info ->
  73         {
  74           UUID chatRoomId = info.getId();
  75           InMemoryChatMessageService chatMessageService =
  76               new InMemoryChatMessageService(chatRoomId);
  77
  78           chatRoomInfo.put(chatRoomId, info);
  79           chatRoomData.put(
  80               info.getId(),
  81               new ChatRoomData(
  82                   clock,
  83                   chatMessageService,
  84                   historyLimit));
  85
  86           return chatMessageService.restore(storageStrategy);
  87         })
  88         .count()
  89         .doOnSuccess(count -> log.info("Restored {} with {} chat-rooms", this, count))
  90         .doOnError(throwable -> log.error("Could not restore {}", this))
  91         .then();
  92   }
  93
  94
  95   @Override
  96   public Mono<ChatRoomInfo> createChatRoom(UUID id, String name)
  97   {
  98     log.info("Creating ChatRoom with history-limit {}", historyLimit);
  99     ChatMessageService service = new InMemoryChatMessageService(id);
 100     ChatRoomInfo chatRoomInfo = new ChatRoomInfo(id, name, shard);
 101     this.chatRoomInfo.put(id, chatRoomInfo);
 102     ChatRoomData chatRoomData = new ChatRoomData(clock, service, historyLimit);
 103     this.chatRoomData.put(id, chatRoomData);
 104     return Mono.just(chatRoomInfo);
 105   }
 106
 107   @Override
 108   public Mono<ChatRoomInfo> getChatRoomInfo(UUID id)
 109   {
 110     return Mono
 111         .justOrEmpty(chatRoomInfo.get(id))
 112         .switchIfEmpty(Mono.error(() -> new UnknownChatroomException(id)));
 113   }
 114
 115   @Override
 116   public Flux<ChatRoomInfo> getChatRoomInfo()
 117   {
 118     return Flux.fromIterable(chatRoomInfo.values());
 119   }
 120
 121   @Override
 122   public Mono<ChatRoomData> getChatRoomData(UUID id)
 123   {
 124     return Mono
 125         .justOrEmpty(chatRoomData.get(id))
 126         .switchIfEmpty(Mono.error(() -> new UnknownChatroomException(id)));
 127   }
 128
 129   @Override
 130   public Mono<String[]> getShardOwners()
 131   {
 132     return Mono.empty();
 133   }
 134
 135   @Override
 136   public String toString()
 137   {
 138     return SimpleChatHomeService.class.getSimpleName() + ", shard=" + shard;
 139   }
 140 }