address review issues

Author: SzyWilliam

ratis-server/src/main/java/org/apache/ratis/server/impl/RaftServerImpl.java

@@ -114,6 +114,7 @@
 import org.apache.ratis.util.ReferenceCountedObject;
 import org.apache.ratis.util.TimeDuration;
 import org.apache.ratis.util.function.CheckedSupplier;
+import org.apache.ratis.util.function.UncheckedAutoCloseableSupplier;
 
 import java.io.File;
 import java.io.IOException;
@@ -1690,10 +1691,13 @@ leaderId, getMemberId(), currentTerm, followerCommit, inconsistencyReplyNextInde
     });
   }
   private CompletableFuture<Void> appendLog(ReferenceCountedObject<List<LogEntryProto>> entriesRef) {
-    final List<LogEntryProto> entries = entriesRef.retain();
-    final List<ConsecutiveIndices> entriesTermIndices = ConsecutiveIndices.convert(entries);
-    appendLogTermIndices.append(entriesTermIndices);
+    final List<ConsecutiveIndices> entriesTermIndices;
+    try(UncheckedAutoCloseableSupplier<List<LogEntryProto>> entries =  entriesRef.retainAndReleaseOnClose()) {
+      entriesTermIndices = ConsecutiveIndices.convert(entries.get());
+      appendLogTermIndices.append(entriesTermIndices);
+    }
 
+    entriesRef.retain();
     return appendLogFuture.updateAndGet(f -> f.thenCompose(
             ignored -> JavaUtils.allOf(state.getLog().append(entriesRef))))
         .whenComplete((v, e) -> {

ratis-server/src/main/java/org/apache/ratis/server/impl/RaftServerProxy.java

@@ -653,7 +653,8 @@ public CompletableFuture<AppendEntriesReplyProto> appendEntriesAsync(
     try {
       final RaftGroupId groupId = ProtoUtils.toRaftGroupId(request.getServerRequest().getRaftGroupId());
       return getImplFuture(groupId)
-          .thenCompose(impl -> impl.executeSubmitServerRequestAsync(() -> impl.appendEntriesAsync(requestRef)));
+          .thenCompose(impl -> JavaUtils.callAsUnchecked(
+              () -> impl.appendEntriesAsync(requestRef), CompletionException::new));
     } finally {
       requestRef.release();
     }

ratis-server/src/main/java/org/apache/ratis/server/impl/ServerImplUtils.java

@@ -138,13 +138,12 @@ synchronized Long getTerm(long index) {
 
     synchronized void append(List<ConsecutiveIndices> entriesTermIndices) {
       for(ConsecutiveIndices indices : entriesTermIndices) {
-        // validate index0
-        final long index0 = indices.startIndex;
+        // validate startIndex
         final Map.Entry<Long, ConsecutiveIndices> lastEntry = map.lastEntry();
         if (lastEntry != null) {
-          Preconditions.assertSame(lastEntry.getValue().getNextIndex(), index0, "index0");
+          Preconditions.assertSame(lastEntry.getValue().getNextIndex(), indices.startIndex, "startIndex");
         }
-        map.put(index0, indices);
+        map.put(indices.startIndex, indices);
       }
     }