spotless and comment fixes

Author: JonasKunz

server/src/main/java/org/elasticsearch/search/aggregations/metrics/ExponentialHistogramState.java

@@ -60,8 +60,16 @@ public static ExponentialHistogramState create(CircuitBreaker circuitBreaker) {
 
     // Visible for testing
     static ExponentialHistogramState create(CircuitBreaker circuitBreaker, ReleasableExponentialHistogram deserializedHistogram) {
-        circuitBreaker.addEstimateBytesAndMaybeBreak(SHALLOW_SIZE, "exponential-histogram-state");
-        return new ExponentialHistogramState(circuitBreaker, deserializedHistogram);
+        boolean success = false;
+        try {
+            circuitBreaker.addEstimateBytesAndMaybeBreak(SHALLOW_SIZE, "exponential-histogram-state");
+            success = true;
+            return new ExponentialHistogramState(circuitBreaker, deserializedHistogram);
+        } finally {
+            if (success == false) {
+                Releasables.close(deserializedHistogram);
+            }
+        }
     }
 
     private ExponentialHistogramState(CircuitBreaker circuitBreaker, ReleasableExponentialHistogram deserializedHistogram) {
@@ -140,11 +148,11 @@ private static void writeZeroBucket(StreamOutput out, ZeroBucket zb) throws IOEx
     }
 
     private static void writeBuckets(StreamOutput out, ExponentialHistogram.Buckets buckets) throws IOException {
-        // We write the buckets with delta-encoding of the indexes, where a delta of 1 is implicit.
+        // We write the buckets with delta-encoding of the indices, where a delta of 1 is implicit.
         // This allows for a good and yet fast compression using vlongs.
-        // We write the indices as negative values (except for the first index) to distinguish them from the counts
+        // We write the index deltas as negative values (except for the first index) to distinguish them from the counts
         // So for example, the following buckets:
-        // Index:  3    4    5    7    8
+        // Index: _3 | _4 | _5 | _7 | _8
         // Count: 10 | 20 | 30 | 40 | 50
         // Would be written as:
         // 3, 10, 20, 30, -2, 40, 50

server/src/test/java/org/elasticsearch/search/aggregations/metrics/ExponentialHistogramStateTests.java

@@ -28,9 +28,7 @@
 import java.util.stream.IntStream;
 
 import static org.elasticsearch.exponentialhistogram.ExponentialHistogram.MAX_SCALE;
-import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
-import static org.junit.internal.matchers.ThrowableMessageMatcher.hasMessage;
 
 public class ExponentialHistogramStateTests extends ESTestCase {
 
@@ -67,7 +65,13 @@ public void testFailedDeserializationDoesNotLeak() throws IOException {
         ExponentialHistogram histogram = ExponentialHistogram.create(
             4,
             ExponentialHistogramCircuitBreaker.noop(),
-            1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0
+            1.0,
+            2.0,
+            3.0,
+            4.0,
+            5.0,
+            6.0,
+            7.0
         );
 
         ExponentialHistogramState state = ExponentialHistogramState.create(breaker());
@@ -79,10 +83,7 @@ public void testFailedDeserializationDoesNotLeak() throws IOException {
         BytesReference bytes = out.bytes();
         BytesReference invalidBytes = bytes.slice(0, bytes.length() - 1);
 
-        expectThrows(
-            EOFException.class,
-            () -> ExponentialHistogramState.read(breaker(), invalidBytes.streamInput())
-        );
+        expectThrows(EOFException.class, () -> ExponentialHistogramState.read(breaker(), invalidBytes.streamInput()));
     }
 
     public void testAdd() throws IOException {