Removing unused fetch sub phase processor initialization during fetch…

… phase execution

Signed-off-by: Ankit Jain <akjain@amazon.com>

server/src/main/java/org/opensearch/search/fetch/FetchContext.java

@@ -192,6 +192,10 @@ public boolean includeNamedQueriesScore() {
         return searchContext.includeNamedQueriesScore();
     }
 
+    public boolean hasInnerHits() {
+        return searchContext.hasInnerHits();
+    }
+
     /**
      * Configuration for returning inner hits
      */
@@ -213,6 +217,10 @@ public FetchFieldsContext fetchFieldsContext() {
         return searchContext.fetchFieldsContext();
     }
 
+    public boolean hasScriptFields() {
+        return searchContext.hasScriptFields();
+    }
+
     /**
      * Configuration for script fields
      */

server/src/main/java/org/opensearch/search/fetch/subphase/InnerHitsPhase.java

@@ -64,7 +64,7 @@ public InnerHitsPhase(FetchPhase fetchPhase) {
 
     @Override
     public FetchSubPhaseProcessor getProcessor(FetchContext searchContext) {
-        if (searchContext.innerHits() == null) {
+        if (!searchContext.hasInnerHits()) {
             return null;
         }
         Map<String, InnerHitsContext.InnerHitSubContext> innerHits = searchContext.innerHits().getInnerHits();

server/src/main/java/org/opensearch/search/fetch/subphase/ScriptFieldsPhase.java

@@ -54,7 +54,7 @@ public final class ScriptFieldsPhase implements FetchSubPhase {
 
     @Override
     public FetchSubPhaseProcessor getProcessor(FetchContext context) {
-        if (context.scriptFields() == null) {
+        if (!context.hasScriptFields()) {
             return null;
         }
         List<ScriptFieldsContext.ScriptField> scriptFields = context.scriptFields().fields();

server/src/main/java/org/opensearch/search/internal/SearchContext.java

@@ -188,6 +188,10 @@ public final void close() {
 
     public abstract void highlight(SearchHighlightContext highlight);
 
+    public boolean hasInnerHits() {
+        return innerHitsContext != null;
+    }
+
     public InnerHitsContext innerHits() {
         if (innerHitsContext == null) {
             innerHitsContext = new InnerHitsContext();

server/src/test/java/org/opensearch/search/fetch/subphase/InnerHitsPhaseTests.java

@@ -0,0 +1,77 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.search.fetch.subphase;
+
+import org.opensearch.index.query.QueryShardContext;
+import org.opensearch.search.fetch.FetchContext;
+import org.opensearch.search.internal.SearchContext;
+import org.opensearch.search.lookup.SearchLookup;
+import org.opensearch.test.OpenSearchTestCase;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class InnerHitsPhaseTests extends OpenSearchTestCase {
+
+    /*
+    Returns mock search context reused across test methods
+     */
+    private SearchContext getMockSearchContext(final boolean hasInnerHits) {
+        final QueryShardContext queryShardContext = mock(QueryShardContext.class);
+        when(queryShardContext.newFetchLookup()).thenReturn(mock(SearchLookup.class));
+
+        final SearchContext searchContext = mock(SearchContext.class);
+        when(searchContext.hasInnerHits()).thenReturn(hasInnerHits);
+        when(searchContext.getQueryShardContext()).thenReturn(queryShardContext);
+
+        return searchContext;
+    }
+
+    /*
+    Validates that InnerHitsPhase processor is not initialized when no inner hits
+     */
+    public void testInnerHitsNull() {
+        assertNull(new InnerHitsPhase(null).getProcessor(new FetchContext(getMockSearchContext(false))));
+    }
+
+    /*
+    Validates that InnerHitsPhase processor is initialized when inner hits are present
+     */
+    public void testInnerHitsNonNull() {
+        final SearchContext searchContext = getMockSearchContext(true);
+        when(searchContext.innerHits()).thenReturn(new InnerHitsContext());
+
+        assertNotNull(new InnerHitsPhase(null).getProcessor(new FetchContext(searchContext)));
+    }
+
+}

server/src/test/java/org/opensearch/search/fetch/subphase/ScriptFieldsPhaseTests.java

@@ -0,0 +1,77 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.search.fetch.subphase;
+
+import org.opensearch.index.query.QueryShardContext;
+import org.opensearch.search.fetch.FetchContext;
+import org.opensearch.search.internal.SearchContext;
+import org.opensearch.search.lookup.SearchLookup;
+import org.opensearch.test.OpenSearchTestCase;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class ScriptFieldsPhaseTests extends OpenSearchTestCase {
+
+    /*
+    Returns mock search context reused across test methods
+     */
+    private SearchContext getMockSearchContext(final boolean hasScriptFields) {
+        final QueryShardContext queryShardContext = mock(QueryShardContext.class);
+        when(queryShardContext.newFetchLookup()).thenReturn(mock(SearchLookup.class));
+
+        final SearchContext searchContext = mock(SearchContext.class);
+        when(searchContext.hasScriptFields()).thenReturn(hasScriptFields);
+        when(searchContext.getQueryShardContext()).thenReturn(queryShardContext);
+
+        return searchContext;
+    }
+
+    /*
+    Validates that ScriptFieldsPhase processor is not initialized when no script fields
+     */
+    public void testScriptFieldsNull() {
+        assertNull(new ScriptFieldsPhase().getProcessor(new FetchContext(getMockSearchContext(false))));
+    }
+
+    /*
+    Validates that ScriptFieldsPhase processor is initialized when script fields are present
+     */
+    public void testScriptFieldsNonNull() {
+        final SearchContext searchContext = getMockSearchContext(true);
+        when(searchContext.scriptFields()).thenReturn(new ScriptFieldsContext());
+
+        assertNotNull(new ScriptFieldsPhase().getProcessor(new FetchContext(searchContext)));
+    }
+
+}