Minor FieldTypeLookup tweaks (elastic#63944)

Remove the default constructor, make the class final and adjust visibility of its methods: if the class is package private, it makes little sense to have public methods.

Author: javanna

server/src/main/java/org/elasticsearch/index/mapper/FieldTypeLookup.java

@@ -23,7 +23,6 @@
 import org.elasticsearch.common.regex.Regex;
 
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -33,7 +32,7 @@
 /**
  * An immutable container for looking up {@link MappedFieldType}s by their name.
  */
-class FieldTypeLookup implements Iterable<MappedFieldType> {
+final class FieldTypeLookup implements Iterable<MappedFieldType> {
 
     private final Map<String, MappedFieldType> fullNameToFieldType = new HashMap<>();
     private final Map<String, String> aliasToConcreteName = new HashMap<>();
@@ -48,10 +47,6 @@ class FieldTypeLookup implements Iterable<MappedFieldType> {
     private final Map<String, Set<String>> fieldToCopiedFields = new HashMap<>();
     private final DynamicKeyFieldTypeLookup dynamicKeyLookup;
 
-    FieldTypeLookup() {
-        this(Collections.emptyList(), Collections.emptyList());
-    }
-
     FieldTypeLookup(Collection<FieldMapper> fieldMappers,
                     Collection<FieldAliasMapper> fieldAliasMappers) {
         Map<String, DynamicKeyFieldMapper> dynamicKeyMappers = new HashMap<>();
@@ -87,7 +82,7 @@ class FieldTypeLookup implements Iterable<MappedFieldType> {
     /**
      * Returns the mapped field type for the given field name.
      */
-    public MappedFieldType get(String field) {
+    MappedFieldType get(String field) {
         String concreteField = aliasToConcreteName.getOrDefault(field, field);
         MappedFieldType fieldType = fullNameToFieldType.get(concreteField);
         if (fieldType != null) {
@@ -102,7 +97,7 @@ public MappedFieldType get(String field) {
     /**
      * Returns a list of the full names of a simple match regex like pattern against full name and index name.
      */
-    public Set<String> simpleMatchToFullName(String pattern) {
+    Set<String> simpleMatchToFullName(String pattern) {
         Set<String> fields = new HashSet<>();
         for (MappedFieldType fieldType : this) {
             if (Regex.simpleMatch(pattern, fieldType.name())) {
@@ -129,7 +124,7 @@ public Set<String> simpleMatchToFullName(String pattern) {
      *              should be a concrete field and *not* an alias.
      * @return A set of paths in the _source that contain the field's values.
      */
-    public Set<String> sourcePaths(String field) {
+    Set<String> sourcePaths(String field) {
         String resolvedField = field;
         int lastDotIndex = field.lastIndexOf('.');
         if (lastDotIndex > 0) {

server/src/test/java/org/elasticsearch/index/mapper/FieldTypeLookupTests.java

@@ -33,7 +33,7 @@
 public class FieldTypeLookupTests extends ESTestCase {
 
     public void testEmpty() {
-        FieldTypeLookup lookup = new FieldTypeLookup();
+        FieldTypeLookup lookup = new FieldTypeLookup(Collections.emptyList(), Collections.emptyList());
         assertNull(lookup.get("foo"));
         Collection<String> names = lookup.simpleMatchToFullName("foo");
         assertNotNull(names);

test/framework/src/main/java/org/elasticsearch/test/AbstractBuilderTestCase.java

@@ -52,7 +52,6 @@
 import org.elasticsearch.index.cache.bitset.BitsetFilterCache;
 import org.elasticsearch.index.fielddata.IndexFieldDataCache;
 import org.elasticsearch.index.fielddata.IndexFieldDataService;
-import org.elasticsearch.index.mapper.MappedFieldType;
 import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.index.query.QueryShardContext;
 import org.elasticsearch.index.shard.ShardId;
@@ -203,10 +202,6 @@ protected static String expectedFieldName(String builderFieldName) {
         return ALIAS_TO_CONCRETE_FIELD_NAME.getOrDefault(builderFieldName, builderFieldName);
     }
 
-    protected Iterable<MappedFieldType> getMapping() {
-        return serviceHolder.mapperService.fieldTypes();
-    }
-
     @AfterClass
     public static void afterClass() throws Exception {
         IOUtils.close(serviceHolder);