TSDB: Rename some methods (#88790)

This renames a couple of methods on `IndexMode` to be more clear and
adds some javadoc.

modules/reindex/src/main/java/org/elasticsearch/reindex/Reindexer.java

@@ -229,7 +229,7 @@ public class Reindexer {
                 scriptService,
                 sslConfig
             );
-            this.destinationIndexIdMapper = destinationIndexMode(state).buildNoFieldDataIdFieldMapper();
+            this.destinationIndexIdMapper = destinationIndexMode(state).idFieldMapperWithoutFieldData();
         }
 
         private IndexMode destinationIndexMode(ClusterState state) {

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

@@ -191,7 +191,7 @@ public class IndexMetadataVerifier {
                     similarityService,
                     mapperRegistry,
                     () -> null,
-                    indexSettings.getMode().buildNoFieldDataIdFieldMapper(),
+                    indexSettings.getMode().idFieldMapperWithoutFieldData(),
                     scriptService
                 );
                 mapperService.merge(indexMetadata, MapperService.MergeReason.MAPPING_RECOVERY);

server/src/main/java/org/elasticsearch/index/IndexMode.java

@@ -17,6 +17,7 @@ import org.elasticsearch.core.Nullable;
 import org.elasticsearch.index.mapper.DataStreamTimestampFieldMapper;
 import org.elasticsearch.index.mapper.DateFieldMapper;
 import org.elasticsearch.index.mapper.DocumentDimensions;
+import org.elasticsearch.index.mapper.FieldMapper;
 import org.elasticsearch.index.mapper.IdFieldMapper;
 import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.index.mapper.MappingLookup;
@@ -84,13 +85,13 @@ public enum IndexMode {
         }
 
         @Override
-        public MetadataFieldMapper buildTimeSeriesIdFieldMapper() {
+        public MetadataFieldMapper timeSeriesIdFieldMapper() {
             // non time-series indices must not have a TimeSeriesIdFieldMapper
             return null;
         }
 
         @Override
-        public IdFieldMapper buildNoFieldDataIdFieldMapper() {
+        public IdFieldMapper idFieldMapperWithoutFieldData() {
             return ProvidedIdFieldMapper.NO_FIELD_DATA;
         }
 
@@ -170,12 +171,11 @@ public enum IndexMode {
         }
 
         @Override
-        public MetadataFieldMapper buildTimeSeriesIdFieldMapper() {
+        public MetadataFieldMapper timeSeriesIdFieldMapper() {
             return TimeSeriesIdFieldMapper.INSTANCE;
         }
 
-        @Override
-        public IdFieldMapper buildNoFieldDataIdFieldMapper() {
+        public IdFieldMapper idFieldMapperWithoutFieldData() {
             return TsidExtractingIdFieldMapper.INSTANCE;
         }
 
@@ -273,9 +273,16 @@ public enum IndexMode {
     @Nullable
     public abstract CompressedXContent getDefaultMapping();
 
+    /**
+     * Build the {@link FieldMapper} for {@code _id}.
+     */
     public abstract IdFieldMapper buildIdFieldMapper(BooleanSupplier fieldDataEnabled);
 
-    public abstract IdFieldMapper buildNoFieldDataIdFieldMapper();
+    /**
+     * Get the singleton {@link FieldMapper} for {@code _id}. It can never support
+     * field data.
+     */
+    public abstract IdFieldMapper idFieldMapperWithoutFieldData();
 
     /**
      * @return the time range based on the provided index metadata and index mode implementation.
@@ -289,7 +296,7 @@ public enum IndexMode {
      * the _tsid field. The field mapper will be added to the list of the metadata
      * field mappers for the index.
      */
-    public abstract MetadataFieldMapper buildTimeSeriesIdFieldMapper();
+    public abstract MetadataFieldMapper timeSeriesIdFieldMapper();
 
     /**
      * How {@code time_series_dimension} fields are handled by indices in this mode.
@@ -301,6 +308,9 @@ public enum IndexMode {
      */
     public abstract boolean shouldValidateTimestamp();
 
+    /**
+     * Parse a string into an {@link IndexMode}.
+     */
     public static IndexMode fromString(String value) {
         return switch (value) {
             case "standard" -> IndexMode.STANDARD;

server/src/main/java/org/elasticsearch/index/IndexModule.java

@@ -586,7 +586,7 @@ public final class IndexModule {
             new SimilarityService(indexSettings, scriptService, similarities),
             mapperRegistry,
             () -> { throw new UnsupportedOperationException("no index query shard context available"); },
-            indexSettings.getMode().buildNoFieldDataIdFieldMapper(),
+            indexSettings.getMode().idFieldMapperWithoutFieldData(),
             scriptService
         );
     }

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

@@ -90,7 +90,7 @@ public class TimeSeriesIdFieldMapper extends MetadataFieldMapper {
         }
     }
 
-    public static final TypeParser PARSER = new FixedTypeParser(c -> c.getIndexSettings().getMode().buildTimeSeriesIdFieldMapper());
+    public static final TypeParser PARSER = new FixedTypeParser(c -> c.getIndexSettings().getMode().timeSeriesIdFieldMapper());
 
     public static final class TimeSeriesIdFieldType extends MappedFieldType {
         private TimeSeriesIdFieldType() {

server/src/test/java/org/elasticsearch/index/IndexModuleTests.java

@@ -194,7 +194,7 @@ public class IndexModuleTests extends ESTestCase {
             mapperRegistry,
             new IndicesFieldDataCache(settings, listener),
             writableRegistry(),
-            module.indexSettings().getMode().buildNoFieldDataIdFieldMapper(),
+            module.indexSettings().getMode().idFieldMapperWithoutFieldData(),
             null,
             indexDeletionListener,
             emptyMap()

server/src/test/java/org/elasticsearch/index/codec/CodecTests.java

@@ -90,7 +90,7 @@ public class CodecTests extends ESTestCase {
             similarityService,
             mapperRegistry,
             () -> null,
-            settings.getMode().buildNoFieldDataIdFieldMapper(),
+            settings.getMode().idFieldMapperWithoutFieldData(),
             ScriptCompiler.NONE
         );
         return new CodecService(service);

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

@@ -44,7 +44,7 @@ public class MappingParserTests extends MapperServiceTestCase {
             scriptService,
             indexAnalyzers,
             indexSettings,
-            indexSettings.getMode().buildNoFieldDataIdFieldMapper()
+            indexSettings.getMode().idFieldMapperWithoutFieldData()
         );
         Map<String, MetadataFieldMapper.TypeParser> metadataMapperParsers = mapperRegistry.getMetadataMapperParsers(
             indexSettings.getIndexVersionCreated()

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

@@ -265,7 +265,7 @@ public class ParametrizedMapperTests extends MapperServiceTestCase {
             ScriptCompiler.NONE,
             mapperService.getIndexAnalyzers(),
             mapperService.getIndexSettings(),
-            mapperService.getIndexSettings().getMode().buildNoFieldDataIdFieldMapper()
+            mapperService.getIndexSettings().getMode().idFieldMapperWithoutFieldData()
         );
         if (fromDynamicTemplate) {
             pc = new MappingParserContext.DynamicTemplateParserContext(pc);

test/framework/src/main/java/org/elasticsearch/index/MapperTestUtils.java

@@ -64,7 +64,7 @@ public class MapperTestUtils {
             similarityService,
             mapperRegistry,
             () -> null,
-            indexSettings.getMode().buildNoFieldDataIdFieldMapper(),
+            indexSettings.getMode().idFieldMapperWithoutFieldData(),
             ScriptCompiler.NONE
         );
     }

test/framework/src/main/java/org/elasticsearch/index/engine/TranslogHandler.java

@@ -59,7 +59,7 @@ public class TranslogHandler implements Engine.TranslogRecoveryRunner {
             similarityService,
             mapperRegistry,
             () -> null,
-            indexSettings.getMode().buildNoFieldDataIdFieldMapper(),
+            indexSettings.getMode().idFieldMapperWithoutFieldData(),
             null
         );
     }

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

@@ -398,7 +398,7 @@ public abstract class AbstractBuilderTestCase extends ESTestCase {
                 similarityService,
                 mapperRegistry,
                 () -> createShardContext(null),
-                idxSettings.getMode().buildNoFieldDataIdFieldMapper(),
+                idxSettings.getMode().idFieldMapperWithoutFieldData(),
                 ScriptCompiler.NONE
             );
             IndicesFieldDataCache indicesFieldDataCache = new IndicesFieldDataCache(nodeSettings, new IndexFieldDataCache.Listener() {