HSEARCH-3118 Ensure the index structure is initialized by MMapDirecto…

…ryProvider.createDirectory

We'll need that in the following commits, because the index writer will
be created lazily, so the index files won't be created on startup
anymore, which means in particular that someone trying to query a brand
new index will get exceptions because of missing files.

backend/lucene/src/main/java/org/hibernate/search/backend/lucene/lowlevel/directory/impl/MMapDirectoryProvider.java

@@ -7,20 +7,16 @@
 package org.hibernate.search.backend.lucene.lowlevel.directory.impl;
 
 import java.io.IOException;
-import java.lang.invoke.MethodHandles;
-import java.nio.file.Files;
 import java.nio.file.Path;
 
-import org.hibernate.search.backend.lucene.logging.impl.Log;
+import org.hibernate.search.engine.reporting.spi.EventContexts;
+import org.hibernate.search.util.common.impl.SuppressingCloser;
 import org.hibernate.search.util.common.reporting.EventContext;
-import org.hibernate.search.util.common.logging.impl.LoggerFactory;
 
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.MMapDirectory;
 
 public class MMapDirectoryProvider implements DirectoryProvider {
-	private static final Log log = LoggerFactory.make( Log.class, MethodHandles.lookup() );
-
 	private final EventContext backendContext;
 
 	private final Path rootDirectory;
@@ -40,24 +36,17 @@ public String toString() {
 
 	@Override
 	public Directory createDirectory(String indexName) throws IOException {
+		EventContext indexContext = backendContext.append( EventContexts.fromIndexName( indexName ) );
 		Path directoryPath = rootDirectory.resolve( indexName );
-		initializeIndexDirectory( directoryPath );
-		return new MMapDirectory( directoryPath );
-	}
-
-	private void initializeIndexDirectory(Path indexDirectory) {
-		if ( Files.exists( indexDirectory ) ) {
-			if ( !Files.isDirectory( indexDirectory ) || !Files.isWritable( indexDirectory ) ) {
-				throw log.localDirectoryIndexRootDirectoryNotWritableDirectory( indexDirectory, backendContext );
-			}
+		DirectoryHelper.makeSanityCheckedFilesystemDirectory( directoryPath, indexContext );
+		Directory directory = new MMapDirectory( directoryPath );
+		try {
+			DirectoryHelper.initializeIndexIfNeeded( directory, indexContext );
 		}
-		else {
-			try {
-				Files.createDirectories( indexDirectory );
-			}
-			catch (Exception e) {
-				throw log.unableToCreateIndexRootDirectoryForLocalDirectoryBackend( indexDirectory, backendContext, e );
-			}
+		catch (IOException | RuntimeException e) {
+			new SuppressingCloser( e ).push( directory );
+			throw e;
 		}
+		return directory;
 	}
 }