From 6500199fa457b2c94497952ea0aaf8be6de5cdda Mon Sep 17 00:00:00 2001
From: Kai Moritz <kai@juplo.de>
Date: Mon, 11 Sep 2023 18:36:05 +0200
Subject: [PATCH] refactor: Separated channels for data and info --
Moved/copied classes
* Split `ChatRoomChannel` into `InfoChannel` and `DataChannel`
** `DataChannel` manages only data for chat-messages
** `InfoChannel` manages all info-data (at the moment only
`EventChatRoomCreated`)
* Aligned test-setup for kafka-related tests
---
...{ChatRoomChannel.java => DataChannel.java} | 0
.../implementation/kafka/InfoChannel.java | 428 ++++++++++++++++++
.../messages/CommandCreateChatRoomTo.java | 27 --
.../EventChatMessageReceivedTo.java | 0
.../messages/info/EventChatRoomCreated.java | 2 +
.../messages/CommandCreateChatRoomToTest.java | 35 --
.../EventChatMessageReceivedToTest.java | 0
7 files changed, 430 insertions(+), 62 deletions(-)
rename src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/{ChatRoomChannel.java => DataChannel.java} (100%)
create mode 100644 src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/InfoChannel.java
delete mode 100644 src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/CommandCreateChatRoomTo.java
rename src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/{ => data}/EventChatMessageReceivedTo.java (100%)
create mode 100644 src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/info/EventChatRoomCreated.java
delete mode 100644 src/test/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/CommandCreateChatRoomToTest.java
rename src/test/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/{ => data}/EventChatMessageReceivedToTest.java (100%)
diff --git a/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/ChatRoomChannel.java b/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/DataChannel.java
similarity index 100%
rename from src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/ChatRoomChannel.java
rename to 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/InfoChannel.java b/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/InfoChannel.java
new file mode 100644
index 00000000..d94bc659
--- /dev/null
+++ b/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/InfoChannel.java
@@ -0,0 +1,428 @@
+package de.juplo.kafka.chat.backend.implementation.kafka;
+
+import de.juplo.kafka.chat.backend.domain.*;
+import de.juplo.kafka.chat.backend.domain.exceptions.LoadInProgressException;
+import de.juplo.kafka.chat.backend.domain.exceptions.ShardNotOwnedException;
+import de.juplo.kafka.chat.backend.implementation.kafka.messages.AbstractMessageTo;
+import de.juplo.kafka.chat.backend.implementation.kafka.messages.CommandCreateChatRoomTo;
+import de.juplo.kafka.chat.backend.implementation.kafka.messages.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.producer.Producer;
+import org.apache.kafka.clients.producer.ProducerRecord;
+import org.apache.kafka.common.TopicPartition;
+import org.apache.kafka.common.errors.WakeupException;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import java.time.*;
+import java.util.*;
+import java.util.stream.IntStream;
+
+
+@Slf4j
+public class ChatRoomChannel implements Runnable, ConsumerRebalanceListener
+{
+ private final String topic;
+ private final Producer<String, AbstractMessageTo> producer;
+ private final Consumer<String, AbstractMessageTo> consumer;
+ private final ZoneId zoneId;
+ private final int numShards;
+ private final int bufferSize;
+ private final Clock clock;
+ private final boolean[] isShardOwned;
+ private final long[] currentOffset;
+ private final long[] nextOffset;
+ private final Map<UUID, ChatRoomInfo>[] chatRoomInfo;
+ private final Map<UUID, ChatRoomData>[] chatRoomData;
+
+ private boolean running;
+ @Getter
+ private volatile boolean loadInProgress;
+
+
+ public ChatRoomChannel(
+ String topic,
+ Producer<String, AbstractMessageTo> producer,
+ Consumer<String, AbstractMessageTo> consumer,
+ ZoneId zoneId,
+ int numShards,
+ int bufferSize,
+ Clock clock)
+ {
+ log.debug(
+ "Creating ChatRoomChannel for topic {} with {} partitions",
+ topic,
+ numShards);
+ this.topic = topic;
+ this.consumer = consumer;
+ this.producer = producer;
+ this.zoneId = zoneId;
+ this.numShards = numShards;
+ this.bufferSize = bufferSize;
+ this.clock = clock;
+ this.isShardOwned = new boolean[numShards];
+ this.currentOffset = new long[numShards];
+ this.nextOffset = new long[numShards];
+ this.chatRoomInfo = new Map[numShards];
+ this.chatRoomData = new Map[numShards];
+ IntStream
+ .range(0, numShards)
+ .forEach(shard ->
+ {
+ this.chatRoomInfo[shard] = new HashMap<>();
+ this.chatRoomData[shard] = new HashMap<>();
+ });
+ }
+
+
+
+ Mono<ChatRoomInfo> sendCreateChatRoomRequest(
+ UUID chatRoomId,
+ String name)
+ {
+ CommandCreateChatRoomTo createChatRoomRequestTo = CommandCreateChatRoomTo.of(name);
+ return Mono.create(sink ->
+ {
+ ProducerRecord<String, AbstractMessageTo> record =
+ new ProducerRecord<>(
+ topic,
+ chatRoomId.toString(),
+ createChatRoomRequestTo);
+
+ producer.send(record, ((metadata, exception) ->
+ {
+ if (metadata != null)
+ {
+ log.info("Successfully send chreate-request for chat room: {}", createChatRoomRequestTo);
+ ChatRoomInfo chatRoomInfo = new ChatRoomInfo(chatRoomId, name, record.partition());
+ createChatRoom(chatRoomInfo);
+ sink.success(chatRoomInfo);
+ }
+ else
+ {
+ // On send-failure
+ log.error(
+ "Could not send create-request for chat room (id={}, name={}): {}",
+ chatRoomId,
+ name,
+ exception);
+ sink.error(exception);
+ }
+ }));
+ });
+ }
+
+ Mono<Message> sendChatMessage(
+ UUID chatRoomId,
+ Message.MessageKey key,
+ LocalDateTime timestamp,
+ String text)
+ {
+ ZonedDateTime zdt = ZonedDateTime.of(timestamp, zoneId);
+ return Mono.create(sink ->
+ {
+ ProducerRecord<String, AbstractMessageTo> record =
+ new ProducerRecord<>(
+ topic,
+ null,
+ zdt.toEpochSecond(),
+ chatRoomId.toString(),
+ EventChatMessageReceivedTo.of(key.getUsername(), key.getMessageId(), text));
+
+ producer.send(record, ((metadata, exception) ->
+ {
+ if (metadata != null)
+ {
+ // On successful send
+ Message message = new Message(key, metadata.offset(), timestamp, text);
+ log.info("Successfully send message {}", message);
+ sink.success(message);
+ }
+ else
+ {
+ // On send-failure
+ log.error(
+ "Could not send message for chat-room={}, key={}, timestamp={}, text={}: {}",
+ chatRoomId,
+ key,
+ timestamp,
+ text,
+ exception);
+ sink.error(exception);
+ }
+ }));
+ });
+ }
+
+ @Override
+ public void onPartitionsAssigned(Collection<TopicPartition> partitions)
+ {
+ log.info("Newly assigned partitions! Pausing normal operations...");
+ loadInProgress = true;
+
+ consumer.endOffsets(partitions).forEach((topicPartition, currentOffset) ->
+ {
+ int partition = topicPartition.partition();
+ isShardOwned[partition] = true;
+ this.currentOffset[partition] = currentOffset;
+
+ log.info(
+ "Partition assigned: {} - loading messages: next={} -> current={}",
+ partition,
+ nextOffset[partition],
+ currentOffset);
+
+ consumer.seek(topicPartition, nextOffset[partition]);
+ });
+
+ consumer.resume(partitions);
+ }
+
+ @Override
+ public void onPartitionsRevoked(Collection<TopicPartition> partitions)
+ {
+ partitions.forEach(topicPartition ->
+ {
+ int partition = topicPartition.partition();
+ isShardOwned[partition] = false;
+ log.info("Partition revoked: {} - next={}", partition, nextOffset[partition]);
+ });
+ }
+
+ @Override
+ public void onPartitionsLost(Collection<TopicPartition> partitions)
+ {
+ log.warn("Lost partitions: {}, partitions");
+ // TODO: Muss auf den Verlust anders reagiert werden?
+ onPartitionsRevoked(partitions);
+ }
+
+ @Override
+ public void run()
+ {
+ running = true;
+
+ while (running)
+ {
+ try
+ {
+ ConsumerRecords<String, AbstractMessageTo> records = consumer.poll(Duration.ofMinutes(5));
+ log.info("Fetched {} messages", records.count());
+
+ if (loadInProgress)
+ {
+ loadChatRoom(records);
+
+ if (isLoadingCompleted())
+ {
+ log.info("Loading of messages completed! Pausing all owned partitions...");
+ pauseAllOwnedPartions();
+ log.info("Resuming normal operations...");
+ loadInProgress = false;
+ }
+ }
+ else
+ {
+ if (!records.isEmpty())
+ {
+ throw new IllegalStateException("All owned partitions should be paused, when no load is in progress!");
+ }
+ }
+ }
+ catch (WakeupException e)
+ {
+ log.info("Received WakeupException, exiting!");
+ running = false;
+ }
+ }
+
+ log.info("Exiting normally");
+ }
+
+ private void loadChatRoom(ConsumerRecords<String, AbstractMessageTo> records)
+ {
+ for (ConsumerRecord<String, AbstractMessageTo> record : records)
+ {
+ UUID chatRoomId = UUID.fromString(record.key());
+
+ switch (record.value().getType())
+ {
+ case COMMAND_CREATE_CHATROOM:
+ createChatRoom(
+ chatRoomId,
+ (CommandCreateChatRoomTo) record.value(),
+ record.partition());
+ break;
+
+ case EVENT_CHATMESSAGE_RECEIVED:
+ Instant instant = Instant.ofEpochSecond(record.timestamp());
+ LocalDateTime timestamp = LocalDateTime.ofInstant(instant, zoneId);
+ loadChatMessage(
+ chatRoomId,
+ timestamp,
+ record.offset(),
+ (EventChatMessageReceivedTo) record.value(),
+ record.partition());
+ break;
+
+ default:
+ log.debug(
+ "Ignoring message for chat-room {} with offset {}: {}",
+ chatRoomId,
+ record.offset(),
+ record.value());
+ }
+
+ nextOffset[record.partition()] = record.offset() + 1;
+ }
+ }
+
+ private void createChatRoom(
+ UUID chatRoomId,
+ CommandCreateChatRoomTo createChatRoomRequestTo,
+ Integer partition)
+ {
+ log.info(
+ "Loading ChatRoom {} for shard {} with buffer-size {}",
+ chatRoomId,
+ partition,
+ bufferSize);
+ KafkaChatMessageService service = new KafkaChatMessageService(this, chatRoomId);
+ ChatRoomData chatRoomData = new ChatRoomData(
+ clock,
+ service,
+ bufferSize);
+ putChatRoom(
+ chatRoomId,
+ createChatRoomRequestTo.getName(),
+ partition,
+ chatRoomData);
+ }
+
+
+ private void createChatRoom(ChatRoomInfo chatRoomInfo)
+ {
+ UUID id = chatRoomInfo.getId();
+ log.info("Creating ChatRoom {} with buffer-size {}", id, bufferSize);
+ KafkaChatMessageService service = new KafkaChatMessageService(this, id);
+ ChatRoomData chatRoomData = new ChatRoomData(clock, service, bufferSize);
+ putChatRoom(
+ chatRoomInfo.getId(),
+ chatRoomInfo.getName(),
+ chatRoomInfo.getShard(),
+ chatRoomData);
+ }
+
+ private void loadChatMessage(
+ UUID chatRoomId,
+ LocalDateTime timestamp,
+ long offset,
+ EventChatMessageReceivedTo chatMessageTo,
+ int partition)
+ {
+ Message.MessageKey key = Message.MessageKey.of(chatMessageTo.getUser(), chatMessageTo.getId());
+ Message message = new Message(key, offset, timestamp, chatMessageTo.getText());
+
+ ChatRoomData chatRoomData = this.chatRoomData[partition].get(chatRoomId);
+ KafkaChatMessageService kafkaChatRoomService =
+ (KafkaChatMessageService) chatRoomData.getChatRoomService();
+
+ kafkaChatRoomService.persistMessage(message);
+ }
+
+ private boolean isLoadingCompleted()
+ {
+ return IntStream
+ .range(0, numShards)
+ .filter(shard -> isShardOwned[shard])
+ .allMatch(shard -> nextOffset[shard] >= currentOffset[shard]);
+ }
+
+ private void pauseAllOwnedPartions()
+ {
+ consumer.pause(IntStream
+ .range(0, numShards)
+ .filter(shard -> isShardOwned[shard])
+ .mapToObj(shard -> new TopicPartition(topic, shard))
+ .toList());
+ }
+
+
+ private void putChatRoom(
+ UUID chatRoomId,
+ String name,
+ Integer partition,
+ ChatRoomData chatRoomData)
+ {
+ if (this.chatRoomInfo[partition].containsKey(chatRoomId))
+ {
+ log.warn(
+ "Ignoring existing chat-room for {}: {}",
+ partition,
+ chatRoomId);
+ }
+ else
+ {
+ log.info(
+ "Adding new chat-room to partition {}: {}",
+ partition,
+ chatRoomData);
+
+ this.chatRoomInfo[partition].put(
+ chatRoomId,
+ new ChatRoomInfo(chatRoomId, name, partition));
+ this.chatRoomData[partition].put(chatRoomId, chatRoomData);
+ }
+ }
+
+ int[] getOwnedShards()
+ {
+ return IntStream
+ .range(0, numShards)
+ .filter(shard -> isShardOwned[shard])
+ .toArray();
+ }
+
+ Mono<ChatRoomData> getChatRoomData(int shard, UUID id)
+ {
+ if (loadInProgress)
+ {
+ return Mono.error(new LoadInProgressException());
+ }
+
+ if (!isShardOwned[shard])
+ {
+ return Mono.error(new ShardNotOwnedException(shard));
+ }
+
+ return Mono.justOrEmpty(chatRoomData[shard].get(id));
+ }
+
+ Flux<ChatRoomInfo> getChatRoomInfo()
+ {
+ return Flux
+ .fromStream(IntStream.range(0, numShards).mapToObj(i -> Integer.valueOf(i)))
+ .filter(shard -> isShardOwned[shard])
+ .flatMap(shard -> Flux.fromIterable(chatRoomInfo[shard].values()));
+ }
+
+ Mono<ChatRoomInfo> getChatRoomInfo(int shard, UUID id)
+ {
+ if (loadInProgress)
+ {
+ return Mono.error(new LoadInProgressException());
+ }
+
+ if (!isShardOwned[shard])
+ {
+ return Mono.error(new ShardNotOwnedException(shard));
+ }
+
+ return Mono.justOrEmpty(chatRoomInfo[shard].get(id));
+ }
+}
diff --git a/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/CommandCreateChatRoomTo.java b/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/CommandCreateChatRoomTo.java
deleted file mode 100644
index 29ba77c6..00000000
--- a/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/CommandCreateChatRoomTo.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package de.juplo.kafka.chat.backend.implementation.kafka.messages;
-
-import lombok.*;
-
-
-@Getter
-@Setter
-@EqualsAndHashCode
-@ToString
-public class CommandCreateChatRoomTo extends AbstractMessageTo
-{
- private String name;
-
-
- public CommandCreateChatRoomTo()
- {
- super(ToType.COMMAND_CREATE_CHATROOM);
- }
-
-
- public static CommandCreateChatRoomTo of(String name)
- {
- CommandCreateChatRoomTo to = new CommandCreateChatRoomTo();
- to.name = name;
- return to;
- }
-}
diff --git a/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/EventChatMessageReceivedTo.java b/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/data/EventChatMessageReceivedTo.java
similarity index 100%
rename from src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/EventChatMessageReceivedTo.java
rename to src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/data/EventChatMessageReceivedTo.java
diff --git a/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/info/EventChatRoomCreated.java b/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/info/EventChatRoomCreated.java
new file mode 100644
index 00000000..0cf42320
--- /dev/null
+++ b/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/info/EventChatRoomCreated.java
@@ -0,0 +1,2 @@
+package de.juplo.kafka.chat.backend.implementation.kafka.messages.info;public class EventChatRoomCreated {
+}
diff --git a/src/test/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/CommandCreateChatRoomToTest.java b/src/test/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/CommandCreateChatRoomToTest.java
deleted file mode 100644
index b0311126..00000000
--- a/src/test/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/CommandCreateChatRoomToTest.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package de.juplo.kafka.chat.backend.implementation.kafka.messages;
-
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.SerializationFeature;
-import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
-
-import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
-
-
-public class CommandCreateChatRoomToTest
-{
- final String json = """
- {
- "name": "Foo-Room!"
- }""";
-
- ObjectMapper mapper;
-
- @BeforeEach
- public void setUp()
- {
- mapper = new ObjectMapper();
- mapper.registerModule(new JavaTimeModule());
- mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
- }
-
- @Test
- public void testDeserialization() throws Exception
- {
- CommandCreateChatRoomTo message = mapper.readValue(json, CommandCreateChatRoomTo.class);
- assertThat(message.getName()).isEqualTo("Foo-Room!");
- }
-}
diff --git a/src/test/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/EventChatMessageReceivedToTest.java b/src/test/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/data/EventChatMessageReceivedToTest.java
similarity index 100%
rename from src/test/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/EventChatMessageReceivedToTest.java
rename to src/test/java/de/juplo/kafka/chat/backend/implementation/kafka/messages/data/EventChatMessageReceivedToTest.java
--
2.20.1