Remove IndicesService#isMetadataField. (#65782)

This helps avoid checking the index version in various places. Instead the
version check is contained to MapperService.

server/src/main/java/org/elasticsearch/action/admin/indices/mapping/get/TransportGetFieldMappingsIndexAction.java

@@ -20,7 +20,6 @@
 package org.elasticsearch.action.admin.indices.mapping.get;
 
 import org.elasticsearch.ElasticsearchException;
-import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionType;
 import org.elasticsearch.action.admin.indices.mapping.get.GetFieldMappingsResponse.FieldMappingMetadata;
 import org.elasticsearch.action.support.ActionFilters;
@@ -93,8 +92,7 @@ public class TransportGetFieldMappingsIndexAction
     protected GetFieldMappingsResponse shardOperation(final GetFieldMappingsIndexRequest request, ShardId shardId) {
         assert shardId != null;
         IndexService indexService = indicesService.indexServiceSafe(shardId.getIndex());
-        Version indexCreatedVersion = indexService.mapperService().getIndexSettings().getIndexVersionCreated();
-        Predicate<String> metadataFieldPredicate = (f) -> indicesService.isMetadataField(indexCreatedVersion, f);
+        Predicate<String> metadataFieldPredicate = (f) -> indexService.mapperService().isMetadataField(f);
         Predicate<String> fieldPredicate = metadataFieldPredicate.or(indicesService.getFieldFilter().apply(shardId.getIndexName()));
 
         DocumentMapper documentMapper = indexService.mapperService().documentMapper();

server/src/main/java/org/elasticsearch/action/fieldcaps/TransportFieldCapabilitiesIndexAction.java

@@ -122,7 +122,7 @@ public class TransportFieldCapabilitiesIndexAction
         for (String field : fieldNames) {
             MappedFieldType ft = mapperService.fieldType(field);
             if (ft != null) {
-                if (indicesService.isMetadataField(mapperService.getIndexSettings().getIndexVersionCreated(), field)
+                if (mapperService.isMetadataField(field)
                     || fieldPredicate.test(ft.name())) {
                     IndexFieldCapabilities fieldCap = new IndexFieldCapabilities(field, ft.familyTypeName(),
                         ft.isSearchable(), ft.isAggregatable(), ft.meta());

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

@@ -484,7 +484,7 @@ public class MapperService extends AbstractIndexComponent implements Closeable {
      * this method considers all mapper plugins
      */
     public boolean isMetadataField(String field) {
-        return mapperRegistry.isMetadataField(indexVersionCreated, field);
+        return mapperRegistry.getMetadataMapperParsers(indexVersionCreated).containsKey(field);
     }
 
     public synchronized List<String> reloadSearchAnalyzers(AnalysisRegistry registry) throws IOException {

server/src/main/java/org/elasticsearch/indices/IndicesService.java

@@ -29,7 +29,6 @@ import org.apache.lucene.util.CollectionUtil;
 import org.apache.lucene.util.RamUsageEstimator;
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.ResourceAlreadyExistsException;
-import org.elasticsearch.Version;
 import org.elasticsearch.action.admin.indices.stats.CommonStats;
 import org.elasticsearch.action.admin.indices.stats.CommonStatsFlags;
 import org.elasticsearch.action.admin.indices.stats.CommonStatsFlags.Flag;
@@ -1545,13 +1544,6 @@ public class IndicesService extends AbstractLifecycleComponent
         return mapperRegistry.getFieldFilter();
     }
 
-    /**
-     * Returns true if the provided field is a registered metadata field (including ones registered via plugins), false otherwise.
-     */
-    public boolean isMetadataField(Version indexCreatedVersion, String field) {
-        return mapperRegistry.isMetadataField(indexCreatedVersion, field);
-    }
-
     /**
      * Returns <code>true</code> if fielddata is enabled for the {@link IdFieldMapper} field, <code>false</code> otherwise.
      */

server/src/main/java/org/elasticsearch/indices/mapper/MapperRegistry.java

@@ -87,13 +87,6 @@ public final class MapperRegistry {
         return metadataMapperParsers7x;
     }
 
-    /**
-     * Returns true if the provided field is a registered metadata field, false otherwise
-     */
-    public boolean isMetadataField(Version indexCreatedVersion, String field) {
-        return getMetadataMapperParsers(indexCreatedVersion).containsKey(field);
-    }
-
     /**
      * Returns a function that given an index name, returns a predicate that fields must match in order to be returned by get mappings,
      * get index, get field mappings and field capabilities API. Useful to filter the fields that such API return.

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

@@ -19,12 +19,16 @@
 
 package org.elasticsearch.index.mapper;
 
+import org.elasticsearch.Version;
+import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.compress.CompressedXContent;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.index.mapper.MapperService.MergeReason;
+import org.elasticsearch.indices.IndicesModule;
+import org.elasticsearch.test.VersionUtils;
 
 import java.io.IOException;
 
@@ -232,4 +236,22 @@ public class MapperServiceTests extends MapperServiceTestCase {
         assertEquals(testString, documentMapper.mappers().getMapper(testString).simpleName());
     }
 
+    public void testIsMetadataField() throws IOException {
+        Version version = VersionUtils.randomIndexCompatibleVersion(random());
+        Settings settings = Settings.builder()
+            .put(IndexMetadata.SETTING_VERSION_CREATED, version)
+            .build();
+
+        MapperService mapperService = createMapperService(settings, mapping(b -> {}));
+        assertFalse(mapperService.isMetadataField(randomAlphaOfLengthBetween(10, 15)));
+
+        for (String builtIn : IndicesModule.getBuiltInMetadataFields()) {
+            if (NestedPathFieldMapper.NAME.equals(builtIn) && version.before(Version.V_8_0_0)) {
+                continue;   // Nested field does not exist in the 7x line
+            }
+            assertTrue("Expected " + builtIn + " to be a metadata field for version " + version,
+                mapperService.isMetadataField(builtIn));
+        }
+    }
+
 }

server/src/test/java/org/elasticsearch/indices/IndicesServiceTests.java

@@ -53,7 +53,6 @@ import org.elasticsearch.index.engine.InternalEngineFactory;
 import org.elasticsearch.index.mapper.KeywordFieldMapper;
 import org.elasticsearch.index.mapper.Mapper;
 import org.elasticsearch.index.mapper.MapperService;
-import org.elasticsearch.index.mapper.NestedPathFieldMapper;
 import org.elasticsearch.index.shard.IllegalIndexShardStateException;
 import org.elasticsearch.index.shard.IndexShard;
 import org.elasticsearch.index.shard.IndexShardState;
@@ -66,7 +65,6 @@ import org.elasticsearch.plugins.MapperPlugin;
 import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.test.ESSingleNodeTestCase;
 import org.elasticsearch.test.IndexSettingsModule;
-import org.elasticsearch.test.VersionUtils;
 import org.elasticsearch.test.hamcrest.RegexMatcher;
 
 import java.io.IOException;
@@ -517,19 +515,6 @@ public class IndicesServiceTests extends ESSingleNodeTestCase {
         assertThat("unexpected shard stats", indexStats.get(index), equalTo(shardStats));
     }
 
-    public void testIsMetadataField() {
-        IndicesService indicesService = getIndicesService();
-        final Version randVersion = VersionUtils.randomIndexCompatibleVersion(random());
-        assertFalse(indicesService.isMetadataField(randVersion, randomAlphaOfLengthBetween(10, 15)));
-        for (String builtIn : IndicesModule.getBuiltInMetadataFields()) {
-            if (NestedPathFieldMapper.NAME.equals(builtIn) && randVersion.before(Version.V_8_0_0)) {
-                continue;   // Nested field does not exist in the 7x line
-            }
-            assertTrue("Expected " + builtIn + " to be a metadata field for version " + randVersion,
-                indicesService.isMetadataField(randVersion, builtIn));
-        }
-    }
-
     public void testGetEngineFactory() throws IOException {
         final IndicesService indicesService = getIndicesService();