Use OptionalInt instead of Optional<Integer> (#34220)

Optionals containing boxed primitive types are prohibitively costly because they
have two level of boxing. For Optional<Integer> the analogous OptionalInt can be
used to avoid the boxing of the contained int value.

Author: Christoph Büscher

client/rest-high-level/src/test/java/org/elasticsearch/client/RankEvalIT.java

@@ -90,7 +90,7 @@ public void testRankEvalRequest() throws IOException {
             if (id.equals("berlin") || id.equals("amsterdam5")) {
                 assertFalse(hit.getRating().isPresent());
             } else {
-                assertEquals(1, hit.getRating().get().intValue());
+                assertEquals(1, hit.getRating().getAsInt());
             }
         }
         EvalQueryQuality berlinQueryQuality = partialResults.get("berlin_query");
@@ -100,7 +100,7 @@ public void testRankEvalRequest() throws IOException {
         for (RatedSearchHit hit : hitsAndRatings) {
             String id = hit.getSearchHit().getId();
             if (id.equals("berlin")) {
-                assertEquals(1, hit.getRating().get().intValue());
+                assertEquals(1, hit.getRating().getAsInt());
             } else {
                 assertFalse(hit.getRating().isPresent());
             }

modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/DiscountedCumulativeGain.java

@@ -33,7 +33,7 @@
 import java.util.Comparator;
 import java.util.List;
 import java.util.Objects;
-import java.util.Optional;
+import java.util.OptionalInt;
 import java.util.stream.Collectors;
 
 import static org.elasticsearch.common.xcontent.ConstructingObjectParser.constructorArg;
@@ -119,8 +119,8 @@ public Integer getUnknownDocRating() {
 
 
     @Override
-    public Optional<Integer> forcedSearchSize() {
-        return Optional.of(k);
+    public OptionalInt forcedSearchSize() {
+        return OptionalInt.of(k);
     }
 
     @Override
@@ -130,9 +130,13 @@ public EvalQueryQuality evaluate(String taskId, SearchHit[] hits,
         List<Integer> ratingsInSearchHits = new ArrayList<>(ratedHits.size());
         int unratedResults = 0;
         for (RatedSearchHit hit : ratedHits) {
-            // unknownDocRating might be null, in which case unrated docs will be ignored in the dcg calculation.
-            // we still need to add them as a placeholder so the rank of the subsequent ratings is correct
-            ratingsInSearchHits.add(hit.getRating().orElse(unknownDocRating));
+            if (hit.getRating().isPresent()) {
+                ratingsInSearchHits.add(hit.getRating().getAsInt());
+            } else {
+                // unknownDocRating might be null, in which case unrated docs will be ignored in the dcg calculation.
+                // we still need to add them as a placeholder so the rank of the subsequent ratings is correct
+                ratingsInSearchHits.add(unknownDocRating);
+            }
             if (hit.getRating().isPresent() == false) {
                 unratedResults++;
             }

modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/EvaluationMetric.java

@@ -29,7 +29,7 @@
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
+import java.util.OptionalInt;
 import java.util.stream.Collectors;
 
 /**
@@ -64,9 +64,9 @@ static List<RatedSearchHit> joinHitsWithRatings(SearchHit[] hits, List<RatedDocu
             DocumentKey key = new DocumentKey(hit.getIndex(), hit.getId());
             RatedDocument ratedDoc = ratedDocumentMap.get(key);
             if (ratedDoc != null) {
-                ratedSearchHits.add(new RatedSearchHit(hit, Optional.of(ratedDoc.getRating())));
+                ratedSearchHits.add(new RatedSearchHit(hit, OptionalInt.of(ratedDoc.getRating())));
             } else {
-                ratedSearchHits.add(new RatedSearchHit(hit, Optional.empty()));
+                ratedSearchHits.add(new RatedSearchHit(hit, OptionalInt.empty()));
             }
         }
         return ratedSearchHits;
@@ -93,7 +93,7 @@ default double combine(Collection<EvalQueryQuality> partialResults) {
      * this method. The default implementation returns an empty optional.
      * @return the number of search hits this metrics requests
      */
-    default Optional<Integer> forcedSearchSize() {
-        return Optional.empty();
+    default OptionalInt forcedSearchSize() {
+        return OptionalInt.empty();
     }
 }

modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/ExpectedReciprocalRank.java

@@ -32,7 +32,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
-import java.util.Optional;
+import java.util.OptionalInt;
 
 import static org.elasticsearch.common.xcontent.ConstructingObjectParser.constructorArg;
 import static org.elasticsearch.common.xcontent.ConstructingObjectParser.optionalConstructorArg;
@@ -126,8 +126,8 @@ public Integer getUnknownDocRating() {
 
 
     @Override
-    public Optional<Integer> forcedSearchSize() {
-        return Optional.of(k);
+    public OptionalInt forcedSearchSize() {
+        return OptionalInt.of(k);
     }
 
     @Override
@@ -139,9 +139,13 @@ public EvalQueryQuality evaluate(String taskId, SearchHit[] hits, List<RatedDocu
         List<Integer> ratingsInSearchHits = new ArrayList<>(ratedHits.size());
         int unratedResults = 0;
         for (RatedSearchHit hit : ratedHits) {
-            // unknownDocRating might be null, in which case unrated will be ignored in the calculation.
-            // we still need to add them as a placeholder so the rank of the subsequent ratings is correct
-            ratingsInSearchHits.add(hit.getRating().orElse(unknownDocRating));
+            if (hit.getRating().isPresent()) {
+                ratingsInSearchHits.add(hit.getRating().getAsInt());
+            } else {
+                // unknownDocRating might be null, in which case unrated docs will be ignored in the dcg calculation.
+                // we still need to add them as a placeholder so the rank of the subsequent ratings is correct
+                ratingsInSearchHits.add(unknownDocRating);
+            }
             if (hit.getRating().isPresent() == false) {
                 unratedResults++;
             }

modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/MeanReciprocalRank.java

@@ -30,7 +30,7 @@
 import java.io.IOException;
 import java.util.List;
 import java.util.Objects;
-import java.util.Optional;
+import java.util.OptionalInt;
 
 import static org.elasticsearch.common.xcontent.ConstructingObjectParser.constructorArg;
 import static org.elasticsearch.common.xcontent.ConstructingObjectParser.optionalConstructorArg;
@@ -90,8 +90,8 @@ int getK() {
     }
 
     @Override
-    public Optional<Integer> forcedSearchSize() {
-        return Optional.of(k);
+    public OptionalInt forcedSearchSize() {
+        return OptionalInt.of(k);
     }
 
     @Override
@@ -115,9 +115,9 @@ public EvalQueryQuality evaluate(String taskId, SearchHit[] hits, List<RatedDocu
         int firstRelevant = -1;
         int rank = 1;
         for (RatedSearchHit hit : ratedHits) {
-            Optional<Integer> rating = hit.getRating();
+            OptionalInt rating = hit.getRating();
             if (rating.isPresent()) {
-                if (rating.get() >= this.relevantRatingThreshhold) {
+                if (rating.getAsInt() >= this.relevantRatingThreshhold) {
                     firstRelevant = rank;
                     break;
                 }

modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/PrecisionAtK.java

@@ -30,7 +30,7 @@
 import java.io.IOException;
 import java.util.List;
 import java.util.Objects;
-import java.util.Optional;
+import java.util.OptionalInt;
 
 import javax.naming.directory.SearchResult;
 
@@ -144,8 +144,8 @@ public boolean getIgnoreUnlabeled() {
     }
 
     @Override
-    public Optional<Integer> forcedSearchSize() {
-        return Optional.of(k);
+    public OptionalInt forcedSearchSize() {
+        return OptionalInt.of(k);
     }
 
     public static PrecisionAtK fromXContent(XContentParser parser) {
@@ -164,9 +164,9 @@ public EvalQueryQuality evaluate(String taskId, SearchHit[] hits,
         int falsePositives = 0;
         List<RatedSearchHit> ratedSearchHits = joinHitsWithRatings(hits, ratedDocs);
         for (RatedSearchHit hit : ratedSearchHits) {
-            Optional<Integer> rating = hit.getRating();
+            OptionalInt rating = hit.getRating();
             if (rating.isPresent()) {
-                if (rating.get() >= this.relevantRatingThreshhold) {
+                if (rating.getAsInt() >= this.relevantRatingThreshhold) {
                     truePositives++;
                 } else {
                     falsePositives++;

modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/RatedSearchHit.java

@@ -33,40 +33,40 @@
 
 import java.io.IOException;
 import java.util.Objects;
-import java.util.Optional;
+import java.util.OptionalInt;
 
 /**
  * Combines a {@link SearchHit} with a document rating.
  */
 public class RatedSearchHit implements Writeable, ToXContentObject {
 
     private final SearchHit searchHit;
-    private final Optional<Integer> rating;
+    private final OptionalInt rating;
 
-    public RatedSearchHit(SearchHit searchHit, Optional<Integer> rating) {
+    public RatedSearchHit(SearchHit searchHit, OptionalInt rating) {
         this.searchHit = searchHit;
         this.rating = rating;
     }
 
     RatedSearchHit(StreamInput in) throws IOException {
         this(SearchHit.readSearchHit(in),
-                in.readBoolean() == true ? Optional.of(in.readVInt()) : Optional.empty());
+                in.readBoolean() == true ? OptionalInt.of(in.readVInt()) : OptionalInt.empty());
     }
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         searchHit.writeTo(out);
         out.writeBoolean(rating.isPresent());
         if (rating.isPresent()) {
-            out.writeVInt(rating.get());
+            out.writeVInt(rating.getAsInt());
         }
     }
 
     public SearchHit getSearchHit() {
         return this.searchHit;
     }
 
-    public Optional<Integer> getRating() {
+    public OptionalInt getRating() {
         return this.rating;
     }
 
@@ -75,22 +75,21 @@ public XContentBuilder toXContent(XContentBuilder builder, ToXContent.Params par
             throws IOException {
         builder.startObject();
         builder.field("hit", (ToXContent) searchHit);
-        builder.field("rating", rating.orElse(null));
+        builder.field("rating", rating.isPresent() ? rating.getAsInt() : null);
         builder.endObject();
         return builder;
     }
 
     private static final ParseField HIT_FIELD = new ParseField("hit");
     private static final ParseField RATING_FIELD = new ParseField("rating");
-    @SuppressWarnings("unchecked")
     private static final ConstructingObjectParser<RatedSearchHit, Void> PARSER = new ConstructingObjectParser<>("rated_hit", true,
-            a -> new RatedSearchHit((SearchHit) a[0], (Optional<Integer>) a[1]));
+            a -> new RatedSearchHit((SearchHit) a[0], (OptionalInt) a[1]));
 
     static {
         PARSER.declareObject(ConstructingObjectParser.constructorArg(), (p, c) -> SearchHit.fromXContent(p), HIT_FIELD);
         PARSER.declareField(ConstructingObjectParser.constructorArg(),
-                (p) -> p.currentToken() == XContentParser.Token.VALUE_NULL ? Optional.empty() : Optional.of(p.intValue()), RATING_FIELD,
-                ValueType.INT_OR_NULL);
+                (p) -> p.currentToken() == XContentParser.Token.VALUE_NULL ? OptionalInt.empty() : OptionalInt.of(p.intValue()),
+                RATING_FIELD, ValueType.INT_OR_NULL);
     }
 
     public static RatedSearchHit parse(XContentParser parser) throws IOException {

modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/TransportRankEvalAction.java

@@ -119,7 +119,7 @@ LoggingDeprecationHandler.INSTANCE, new BytesArray(resolvedRequest), XContentTyp
             }
 
             if (metric.forcedSearchSize().isPresent()) {
-                evaluationRequest.size(metric.forcedSearchSize().get());
+                evaluationRequest.size(metric.forcedSearchSize().getAsInt());
             }
 
             ratedRequestsInSearch.add(ratedRequest);

modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/PrecisionAtKTests.java

@@ -223,23 +223,24 @@ public void testEqualsAndHash() throws IOException {
     }
 
     private static PrecisionAtK copy(PrecisionAtK original) {
-        return new PrecisionAtK(original.getRelevantRatingThreshold(), original.getIgnoreUnlabeled(), original.forcedSearchSize().get());
+        return new PrecisionAtK(original.getRelevantRatingThreshold(), original.getIgnoreUnlabeled(),
+                original.forcedSearchSize().getAsInt());
     }
 
     private static PrecisionAtK mutate(PrecisionAtK original) {
         PrecisionAtK pAtK;
         switch (randomIntBetween(0, 2)) {
         case 0:
             pAtK = new PrecisionAtK(original.getRelevantRatingThreshold(), !original.getIgnoreUnlabeled(),
-                    original.forcedSearchSize().get());
+                    original.forcedSearchSize().getAsInt());
             break;
         case 1:
             pAtK = new PrecisionAtK(randomValueOtherThan(original.getRelevantRatingThreshold(), () -> randomIntBetween(0, 10)),
-                    original.getIgnoreUnlabeled(), original.forcedSearchSize().get());
+                    original.getIgnoreUnlabeled(), original.forcedSearchSize().getAsInt());
             break;
         case 2:
             pAtK = new PrecisionAtK(original.getRelevantRatingThreshold(),
-                    original.getIgnoreUnlabeled(), original.forcedSearchSize().get() + 1);
+                    original.getIgnoreUnlabeled(), original.forcedSearchSize().getAsInt() + 1);
             break;
         default:
             throw new IllegalStateException("The test should only allow three parameters mutated");

modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/RankEvalRequestIT.java

@@ -128,7 +128,7 @@ public void testPrecisionAtRequest() {
                     if (id.equals("1") || id.equals("6")) {
                         assertFalse(hit.getRating().isPresent());
                     } else {
-                        assertEquals(RELEVANT_RATING_1, hit.getRating().get().intValue());
+                        assertEquals(RELEVANT_RATING_1, hit.getRating().getAsInt());
                     }
                 }
             }
@@ -139,7 +139,7 @@ public void testPrecisionAtRequest() {
                 for (RatedSearchHit hit : hitsAndRatings) {
                     String id = hit.getSearchHit().getId();
                     if (id.equals("1")) {
-                        assertEquals(RELEVANT_RATING_1, hit.getRating().get().intValue());
+                        assertEquals(RELEVANT_RATING_1, hit.getRating().getAsInt());
                     } else {
                         assertFalse(hit.getRating().isPresent());
                     }

modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/RankEvalResponseTests.java

@@ -50,7 +50,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
+import java.util.OptionalInt;
 import java.util.function.Predicate;
 
 import static java.util.Collections.singleton;
@@ -182,6 +182,6 @@ private static RatedSearchHit searchHit(String index, int docId, Integer rating)
         SearchHit hit = new SearchHit(docId, docId + "", new Text(""), Collections.emptyMap());
         hit.shard(new SearchShardTarget("testnode", new Index(index, "uuid"), 0, null));
         hit.score(1.0f);
-        return new RatedSearchHit(hit, rating != null ? Optional.of(rating) : Optional.empty());
+        return new RatedSearchHit(hit, rating != null ? OptionalInt.of(rating) : OptionalInt.empty());
     }
 }

modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/RatedSearchHitTests.java

@@ -30,28 +30,28 @@
 
 import java.io.IOException;
 import java.util.Collections;
-import java.util.Optional;
+import java.util.OptionalInt;
 
 import static org.elasticsearch.test.EqualsHashCodeTestUtils.checkEqualsAndHashCode;
 import static org.elasticsearch.test.XContentTestUtils.insertRandomFields;
 
 public class RatedSearchHitTests extends ESTestCase {
 
     public static RatedSearchHit randomRatedSearchHit() {
-        Optional<Integer> rating = randomBoolean() ? Optional.empty()
-                : Optional.of(randomIntBetween(0, 5));
+        OptionalInt rating = randomBoolean() ? OptionalInt.empty()
+                : OptionalInt.of(randomIntBetween(0, 5));
         SearchHit searchHit = new SearchHit(randomIntBetween(0, 10), randomAlphaOfLength(10),
                 new Text(randomAlphaOfLength(10)), Collections.emptyMap());
         RatedSearchHit ratedSearchHit = new RatedSearchHit(searchHit, rating);
         return ratedSearchHit;
     }
 
     private static RatedSearchHit mutateTestItem(RatedSearchHit original) {
-        Optional<Integer> rating = original.getRating();
+        OptionalInt rating = original.getRating();
         SearchHit hit = original.getSearchHit();
         switch (randomIntBetween(0, 1)) {
         case 0:
-            rating = rating.isPresent() ? Optional.of(rating.get() + 1) : Optional.of(randomInt(5));
+            rating = rating.isPresent() ? OptionalInt.of(rating.getAsInt() + 1) : OptionalInt.of(randomInt(5));
             break;
         case 1:
             hit = new SearchHit(hit.docId(), hit.getId() + randomAlphaOfLength(10),

server/src/main/java/org/elasticsearch/cluster/metadata/AutoExpandReplicas.java

@@ -27,7 +27,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
+import java.util.OptionalInt;
 
 /**
  * This class acts as a functional wrapper around the {@code index.auto_expand_replicas} setting.
@@ -93,7 +93,7 @@ int getMaxReplicas(int numDataNodes) {
         return Math.min(maxReplicas, numDataNodes-1);
     }
 
-    Optional<Integer> getDesiredNumberOfReplicas(int numDataNodes) {
+    private OptionalInt getDesiredNumberOfReplicas(int numDataNodes) {
         if (enabled) {
             final int min = getMinReplicas();
             final int max = getMaxReplicas(numDataNodes);
@@ -105,10 +105,10 @@ Optional<Integer> getDesiredNumberOfReplicas(int numDataNodes) {
             }
 
             if (numberOfReplicas >= min && numberOfReplicas <= max) {
-                return Optional.of(numberOfReplicas);
+                return OptionalInt.of(numberOfReplicas);
             }
         }
-        return Optional.empty();
+        return OptionalInt.empty();
     }
 
     @Override