HSEARCH-2531 Make configuration-based index name override work with E…

…lasticsearchIndexManager

We used to apply this override on the attribute returned by
getIndexName(), which is really not a good idea: Hibernate Search works
in such a way that it expects the index name returned by getIndexName()
to be the exact same that was passed to the initialize() method.

Because we did change the returned getIndexName(), we couldn't retrieve
the index manager anymore when indexing and indexing failed
consistently.

Possible solutions were:

 * to align ElasticsearchIndexManager's behavior on that of
   DirectoryBasedIndexManager, making getIndexName() return the exact
   string that was passed to the initialize() method.
 * to make the index name passed to the initialize() method already
   account for the override. But that would be a breaking change to
   existing IndexManager implementations.
 * to make Hibernate Search ask newly created index managers for their
   actual name after initializing them (by calling getActualName is
   available or getIndexName otherwise). But that would be a breaking
   change to clients of SearchIntegrator.getIndexManager.

I chose the first solution, which is more hackish, but safer in the
current context of a candidate release.

elasticsearch/src/main/java/org/hibernate/search/elasticsearch/impl/ElasticsearchIndexManager.java

@@ -59,8 +59,25 @@ public class ElasticsearchIndexManager implements IndexManager, IndexNameNormali
 
 	static final Log LOG = LoggerFactory.make( Log.class );
 
+	/**
+	 * The index name for Hibernate Search, which is actually
+	 * the index <em>manager</em> name.
+	 * <p>
+	 * Following the behavior of Lucene index managers, this
+	 * name will reflect any annotation-based index name override
+	 * ({@code @Indexed(index = "override")}) but will ignore
+	 * configuration-based override
+	 * ({@code hibernate.search.my.package.MyClass.indexName = foo}),
+	 * which is only reflected in {@link #actualIndexName}.
+	 */
 	private String indexName;
+
+	/**
+	 * The index name for the Elasticsearch module, i.e. the
+	 * actual name of the underlying Elasticsearch index.
+	 */
 	private String actualIndexName;
+
 	private boolean refreshAfterWrite;
 	private IndexSchemaManagementStrategy schemaManagementStrategy;
 	private ExecutionOptions schemaManagementExecutionOptions;
@@ -91,7 +108,7 @@ public class ElasticsearchIndexManager implements IndexManager, IndexNameNormali
 	public void initialize(String indexName, Properties properties, Similarity similarity, WorkerBuildContext context) {
 		this.serviceManager = context.getServiceManager();
 
-		this.indexName = getIndexName( indexName, properties );
+		this.indexName = indexName;
 		this.schemaManagementStrategy = getIndexManagementStrategy( properties );
 		final ElasticsearchIndexStatus requiredIndexStatus = getRequiredIndexStatus( properties );
 		final int indexManagementWaitTimeout = getIndexManagementWaitTimeout( properties );
@@ -124,7 +141,8 @@ public DynamicType getDynamicMapping() {
 		this.schemaValidator = serviceManager.requestService( ElasticsearchSchemaValidator.class );
 		this.schemaTranslator = serviceManager.requestService( ElasticsearchSchemaTranslator.class );
 
-		this.actualIndexName = ElasticsearchIndexNameNormalizer.getElasticsearchIndexName( this.indexName );
+		String overriddenIndexName = getOverriddenIndexName( indexName, properties );
+		this.actualIndexName = ElasticsearchIndexNameNormalizer.getElasticsearchIndexName( overriddenIndexName );
 		this.refreshAfterWrite = getRefreshAfterWrite( properties );
 
 		this.similarity = similarity;
@@ -137,7 +155,7 @@ public DynamicType getDynamicMapping() {
 		this.requestProcessor = context.getServiceManager().requestService( BackendRequestProcessor.class );
 	}
 
-	private static String getIndexName(String indexName, Properties properties) {
+	private static String getOverriddenIndexName(String indexName, Properties properties) {
 		String name = properties.getProperty( Environment.INDEX_NAME_PROP_NAME );
 		return name != null ? name : indexName;
 	}