feat(tracker): scaffold module, move event queue classes, add interfaces and tests

- New `tracker` Maven module with EventSender, EventQueueStats, NoopEventQueueStats interfaces
- Moved Event, WrappedEvent, EventsStorage*, InMemoryEventsStorage, EventsTask, NoopEventsStorageImp from client to tracker (package unchanged)
- InMemoryEventsStorage now takes EventQueueStats instead of TelemetryRuntimeProducer (no Guava)
- EventsTask now takes EventSender instead of concrete EventsSender (no Guava)
- Added TelemetryEventQueueStats adapter in client to bridge TelemetryRuntimeProducer → EventQueueStats
- EventsSender implements EventSender for backward compatibility
- 10 unit tests (InMemoryEventsStorageTest x6, EventsTaskTest x4), all passing

AI-Session-Id: 4466fe43-9eac-430f-9e06-bb156dfd7edf
AI-Tool: claude-code
AI-Model: unknown

Author: gthea

client/pom.xml

@@ -167,6 +167,11 @@
     </properties>
 
     <dependencies>
+        <dependency>
+            <groupId>io.split.client</groupId>
+            <artifactId>tracker</artifactId>
+            <version>${project.version}</version>
+        </dependency>
         <dependency>
             <groupId>io.split.client</groupId>
             <artifactId>targeting-engine</artifactId>

client/src/main/java/io/split/client/SplitFactoryImpl.java

@@ -9,6 +9,8 @@
 import io.split.client.events.EventsTask;
 import io.split.client.events.InMemoryEventsStorage;
 import io.split.client.events.NoopEventsStorageImp;
+import io.split.client.events.EventQueueStats;
+import io.split.client.events.TelemetryEventQueueStats;
 import io.split.client.impressions.AsynchronousImpressionListener;
 import io.split.client.impressions.HttpImpressionsSender;
 import io.split.client.impressions.ImpressionCounter;
@@ -254,7 +256,8 @@ public SplitFactoryImpl(String apiToken, SplitClientConfig config) throws URISyn
         _impressionsManager = buildImpressionsManager(config, impressionsStorage, impressionsStorage);
 
         // EventClient
-        EventsStorage eventsStorage = new InMemoryEventsStorage(config.eventsQueueSize(), _telemetryStorageProducer);
+        EventQueueStats eventsQueueStats = new TelemetryEventQueueStats(_telemetryStorageProducer);
+        EventsStorage eventsStorage = new InMemoryEventsStorage(config.eventsQueueSize(), eventsQueueStats);
         EventsSender eventsSender = EventsSender.create(_splitHttpClient, _eventsRootTarget, _telemetryStorageProducer);
         _eventsTask = EventsTask.create(config.eventSendIntervalInMillis(), eventsStorage, eventsSender,
                 config.getThreadFactory());

client/src/main/java/io/split/client/events/EventsSender.java

@@ -14,7 +14,7 @@
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
-public class EventsSender {
+public class EventsSender implements io.split.client.events.EventSender {
 
     private static final String BULK_ENDPOINT_PATH = "api/events/bulk";
     private final URI _bulkEndpoint;
@@ -34,10 +34,15 @@ public static EventsSender create(SplitHttpClient splitHttpclient, URI eventsTar
         _httpPostImp = new HttpPostImp(_client, telemetryRuntimeProducer);
     }
 
-    public void sendEvents(List<Event> _data) {
+    @Override
+    public void send(List<Event> _data) {
         _httpPostImp.post(_bulkEndpoint, _data, "Events ", HttpParamsWrapper.EVENTS);
     }
 
+    public void sendEvents(List<Event> _data) {
+        send(_data);
+    }
+
     @VisibleForTesting
     URI getBulkEndpoint() {
         return _bulkEndpoint;

client/src/main/java/io/split/client/events/TelemetryEventQueueStats.java

@@ -0,0 +1,25 @@
+package io.split.client.events;
+
+import io.split.telemetry.domain.enums.EventsDataRecordsEnum;
+import io.split.telemetry.storage.TelemetryRuntimeProducer;
+
+import java.util.Objects;
+
+public class TelemetryEventQueueStats implements EventQueueStats {
+
+    private final TelemetryRuntimeProducer _telemetryRuntimeProducer;
+
+    public TelemetryEventQueueStats(TelemetryRuntimeProducer telemetryRuntimeProducer) {
+        _telemetryRuntimeProducer = Objects.requireNonNull(telemetryRuntimeProducer);
+    }
+
+    @Override
+    public void onQueued(long count) {
+        _telemetryRuntimeProducer.recordEventStats(EventsDataRecordsEnum.EVENTS_QUEUED, count);
+    }
+
+    @Override
+    public void onDropped(long count) {
+        _telemetryRuntimeProducer.recordEventStats(EventsDataRecordsEnum.EVENTS_DROPPED, count);
+    }
+}

client/src/test/java/io/split/client/events/EventsTaskTest.java

@@ -71,6 +71,7 @@
         <module>redis-wrapper</module>
         <module>testing</module>
         <module>okhttp-modules</module>
+        <module>tracker</module>
         <module>client</module>
     </modules>
     <build>

client/src/test/java/io/split/client/events/InMemoryEventsStorageTest.java

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
+         http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>io.split.client</groupId>
+    <artifactId>java-client-parent</artifactId>
+    <version>4.18.3</version>
+  </parent>
+
+  <artifactId>tracker</artifactId>
+  <packaging>jar</packaging>
+  <name>Tracker</name>
+  <description>Shared event queue, scheduler, and HTTP-injected delivery</description>
+
+  <dependencies>
+    <dependency>
+      <groupId>com.google.code.gson</groupId>
+      <artifactId>gson</artifactId>
+      <version>2.13.1</version>
+    </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+      <version>1.7.36</version>
+    </dependency>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-core</artifactId>
+      <version>1.10.19</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+</project>

pom.xml

@@ -1,9 +1,9 @@
 package io.split.client.dtos;
 
-import com.google.common.base.Objects;
 import com.google.gson.annotations.SerializedName;
 
 import java.util.Map;
+import java.util.Objects;
 
 public class Event {
 
@@ -36,13 +36,13 @@ public boolean equals(Object o) {
         Event event = (Event) o;
         return Double.compare(event.value, value) == 0 &&
                 timestamp == event.timestamp &&
-                Objects.equal(eventTypeId, event.eventTypeId) &&
-                Objects.equal(trafficTypeName, event.trafficTypeName) &&
-                Objects.equal(key, event.key);
+                Objects.equals(eventTypeId, event.eventTypeId) &&
+                Objects.equals(trafficTypeName, event.trafficTypeName) &&
+                Objects.equals(key, event.key);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hashCode(eventTypeId, trafficTypeName, key, value, timestamp);
+        return Objects.hash(eventTypeId, trafficTypeName, key, value, timestamp);
     }
 }

tracker/pom.xml

@@ -0,0 +1,6 @@
+package io.split.client.events;
+
+public interface EventQueueStats {
+    void onQueued(long count);
+    void onDropped(long count);
+}