From 28b4d95cf5aea2632fa3c57f9714bad93784df9f Mon Sep 17 00:00:00 2001
From: Colin Goodheart-Smithe <colings86@users.noreply.github.com>
Date: Fri, 3 Nov 2017 08:51:40 +0000
Subject: [PATCH] Uses norms for exists query if enabled (#27237)

* Uses norms for exists query if enabled

This change means that for indexes created from 6.1.0, if normas are enabled we will not write the field name to the `_field_names` field and for an exists query we will instead use the NormsFieldExistsQuery which was added in Lucene 7.1.0. If norms are not enabled or if the index was created before 6.1.0 `_field_names` will be used as before.

* Fixes tests
---
 .../elasticsearch/index/mapper/TextFieldMapper.java  | 12 +++++++-----
 .../index/mapper/FieldNamesFieldMapperTests.java     |  3 ++-
 .../index/query/ExistsQueryBuilderTests.java         |  5 +++++
 .../index/query/RangeQueryBuilderTests.java          |  4 ++++
 4 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/core/src/main/java/org/elasticsearch/index/mapper/TextFieldMapper.java b/core/src/main/java/org/elasticsearch/index/mapper/TextFieldMapper.java
index 24c3443658a..ae99f743fe5 100644
--- a/core/src/main/java/org/elasticsearch/index/mapper/TextFieldMapper.java
+++ b/core/src/main/java/org/elasticsearch/index/mapper/TextFieldMapper.java
@@ -23,7 +23,7 @@ import org.apache.lucene.document.Field;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.IndexableField;
 import org.apache.lucene.index.Term;
-import org.apache.lucene.search.DocValuesFieldExistsQuery;
+import org.apache.lucene.search.NormsFieldExistsQuery;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.TermQuery;
 import org.elasticsearch.common.settings.Settings;
@@ -280,10 +280,10 @@ public class TextFieldMapper extends FieldMapper {
 
         @Override
         public Query existsQuery(QueryShardContext context) {
-            if (hasDocValues()) {
-                return new DocValuesFieldExistsQuery(name());
-            } else {
+            if (omitNorms()) {
                 return new TermQuery(new Term(FieldNamesFieldMapper.NAME, name()));
+            } else {
+                return new NormsFieldExistsQuery(name());
             }
         }
 
@@ -345,7 +345,9 @@ public class TextFieldMapper extends FieldMapper {
         if (fieldType().indexOptions() != IndexOptions.NONE || fieldType().stored()) {
             Field field = new Field(fieldType().name(), value, fieldType());
             fields.add(field);
-            createFieldNamesField(context, fields);
+            if (fieldType().omitNorms()) {
+                createFieldNamesField(context, fields);
+            }
         }
     }
 
diff --git a/core/src/test/java/org/elasticsearch/index/mapper/FieldNamesFieldMapperTests.java b/core/src/test/java/org/elasticsearch/index/mapper/FieldNamesFieldMapperTests.java
index 70022dc6326..3655f04fcbb 100644
--- a/core/src/test/java/org/elasticsearch/index/mapper/FieldNamesFieldMapperTests.java
+++ b/core/src/test/java/org/elasticsearch/index/mapper/FieldNamesFieldMapperTests.java
@@ -26,6 +26,7 @@ import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.test.ESSingleNodeTestCase;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.Set;
 import java.util.SortedSet;
 import java.util.TreeSet;
@@ -87,7 +88,7 @@ public class FieldNamesFieldMapperTests extends ESSingleNodeTestCase {
                 .bytes(),
                 XContentType.JSON));
 
-        assertFieldNames(set("a"), doc);
+        assertFieldNames(Collections.emptySet(), doc);
     }
 
     public void testExplicitEnabled() throws Exception {
diff --git a/core/src/test/java/org/elasticsearch/index/query/ExistsQueryBuilderTests.java b/core/src/test/java/org/elasticsearch/index/query/ExistsQueryBuilderTests.java
index 40d3f90dd4e..d4547eee26f 100644
--- a/core/src/test/java/org/elasticsearch/index/query/ExistsQueryBuilderTests.java
+++ b/core/src/test/java/org/elasticsearch/index/query/ExistsQueryBuilderTests.java
@@ -24,6 +24,7 @@ import org.apache.lucene.search.BooleanQuery;
 import org.apache.lucene.search.ConstantScoreQuery;
 import org.apache.lucene.search.DocValuesFieldExistsQuery;
 import org.apache.lucene.search.MatchNoDocsQuery;
+import org.apache.lucene.search.NormsFieldExistsQuery;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.TermQuery;
 import org.elasticsearch.Version;
@@ -113,6 +114,10 @@ public class ExistsQueryBuilderTests extends AbstractQueryTestCase<ExistsQueryBu
                 assertThat(constantScoreQuery.getQuery(), instanceOf(DocValuesFieldExistsQuery.class));
                 DocValuesFieldExistsQuery dvExistsQuery = (DocValuesFieldExistsQuery) constantScoreQuery.getQuery();
                 assertEquals(field, dvExistsQuery.getField());
+            } else if (context.getQueryShardContext().getMapperService().fullName(field).omitNorms() == false) {
+                assertThat(constantScoreQuery.getQuery(), instanceOf(NormsFieldExistsQuery.class));
+                NormsFieldExistsQuery normsExistsQuery = (NormsFieldExistsQuery) constantScoreQuery.getQuery();
+                assertEquals(field, normsExistsQuery.getField());
             } else {
                 assertThat(constantScoreQuery.getQuery(), instanceOf(TermQuery.class));
                 TermQuery termQuery = (TermQuery) constantScoreQuery.getQuery();
diff --git a/core/src/test/java/org/elasticsearch/index/query/RangeQueryBuilderTests.java b/core/src/test/java/org/elasticsearch/index/query/RangeQueryBuilderTests.java
index ad3946a6755..2230436b18e 100644
--- a/core/src/test/java/org/elasticsearch/index/query/RangeQueryBuilderTests.java
+++ b/core/src/test/java/org/elasticsearch/index/query/RangeQueryBuilderTests.java
@@ -26,6 +26,7 @@ import org.apache.lucene.search.ConstantScoreQuery;
 import org.apache.lucene.search.DocValuesFieldExistsQuery;
 import org.apache.lucene.search.IndexOrDocValuesQuery;
 import org.apache.lucene.search.MatchNoDocsQuery;
+import org.apache.lucene.search.NormsFieldExistsQuery;
 import org.apache.lucene.search.PointRangeQuery;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.TermQuery;
@@ -129,6 +130,9 @@ public class RangeQueryBuilderTests extends AbstractQueryTestCase<RangeQueryBuil
                 if (context.mapperService().getIndexSettings().getIndexVersionCreated().onOrAfter(Version.V_6_1_0)
                         && context.mapperService().fullName(queryBuilder.fieldName()).hasDocValues()) {
                     expectedQuery = new ConstantScoreQuery(new DocValuesFieldExistsQuery(queryBuilder.fieldName()));
+                } else if (context.mapperService().getIndexSettings().getIndexVersionCreated().onOrAfter(Version.V_6_1_0)
+                        && context.mapperService().fullName(queryBuilder.fieldName()).omitNorms() == false) {
+                    expectedQuery = new ConstantScoreQuery(new NormsFieldExistsQuery(queryBuilder.fieldName()));
                 } else {
                     expectedQuery = new ConstantScoreQuery(new TermQuery(new Term(FieldNamesFieldMapper.NAME, queryBuilder.fieldName())));
                 }