Added a log about the first leaf response received by the learner

Signed-off-by: Artem Ananev <[email protected]>

platform-sdk/swirlds-virtualmap/src/main/java/com/swirlds/virtualmap/internal/reconnect/LearnerPullVirtualTreeView.java

@@ -16,6 +16,7 @@
 
 package com.swirlds.virtualmap.internal.reconnect;
 
+import static com.swirlds.logging.legacy.LogMarker.RECONNECT;
 import static com.swirlds.virtualmap.internal.Path.ROOT_PATH;
 
 import com.swirlds.common.crypto.CryptographyHolder;
@@ -51,6 +52,8 @@
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 /**
  * An implementation of {@link LearnerTreeView} for the virtual merkle. The learner during reconnect
@@ -69,6 +72,8 @@
 public final class LearnerPullVirtualTreeView<K extends VirtualKey, V extends VirtualValue>
         extends VirtualTreeViewBase<K, V> implements LearnerTreeView<Long> {
 
+    private static final Logger logger = LogManager.getLogger(LearnerPullVirtualTreeView.class);
+
     /**
      * A stashed null hash, which is used for any leaves which are null that we need to send
      * (specifically, leaf 2 for a tree with only a single leaf).
@@ -312,6 +317,7 @@ private void handleResponse(final PullVirtualTreeResponse response) {
 
         if (isLeaf) {
             if (firstLeaf) {
+                logger.info(RECONNECT.getMarker(), "First leaf response received, view={}", viewId);
                 root.prepareForFirstLeaf();
                 firstLeaf = false;
             }