Improve the use of the file-index for combined file-access

BlueMapCore/src/main/java/de/bluecolored/bluemap/core/resourcepack/fileaccess/CombinedFileAccess.java

@@ -34,25 +34,37 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 public class CombinedFileAccess implements FileAccess {
 
+	private final ReentrantReadWriteLock rwLock = new ReentrantReadWriteLock();
+	
 	public List<FileAccess> sources;
 	private Map<String, FileAccess> sourceMap;
 	
+	private Set<String> allFiles;
+	
 	public CombinedFileAccess() {
 		sources = new ArrayList<>();
 		sourceMap = new HashMap<>();
+		allFiles = new HashSet<>();
 	}
 	
 	public void addFileAccess(FileAccess source) {
-		synchronized (sources) {
+		rwLock.writeLock().lock();
+		
+		try {
 			sources.add(source);
-		}
-		synchronized (sourceMap) {
-			for (String path : source.listFiles("", true)) {
+			
+			Collection<String> sourceFiles = source.listFiles("", true);
+			for (String path : sourceFiles) {
 				sourceMap.put(FileAccess.normalize(path), source);
 			}
+
+			allFiles.addAll(sourceFiles);
+		} finally {
+			rwLock.writeLock().unlock();
 		}
 	}
 
@@ -63,9 +75,12 @@ public String getName() {
 	
 	@Override
 	public InputStream readFile(String path) throws FileNotFoundException, IOException {
-		synchronized (sourceMap) {
+		rwLock.readLock().lock();
+		try {
 			FileAccess source = sourceMap.get(FileAccess.normalize(path));
 			if (source != null) return source.readFile(path);
+		} finally {
+			rwLock.readLock().unlock();
 		}
 		
 		throw new FileNotFoundException("File " + path + " does not exist in any of the sources!");
@@ -73,25 +88,70 @@ public InputStream readFile(String path) throws FileNotFoundException, IOExcepti
 
 	@Override
 	public Collection<String> listFiles(String path, boolean recursive) {
-		Set<String> files = new HashSet<>();
+		path = normalizeFolderPath(path);
+		Collection<String> files = new ArrayList<String>();
 		
-		synchronized (sources) {
-			for (int i = 0; i < sources.size(); i++) {
-				files.addAll(sources.get(i).listFiles(path, recursive));
+		rwLock.readLock().lock();
+		try {
+			for (String file : allFiles) {
+				int nameSplit = file.lastIndexOf('/');
+				String filePath = "";
+				if (nameSplit != -1) {
+					filePath = file.substring(0, nameSplit);
 				}
+				filePath = normalizeFolderPath(filePath);
+				
+				if (recursive) {
+					if (!filePath.startsWith(path) && !path.equals(filePath)) continue;
+				} else {
+					if (!path.equals(filePath)) continue;
+				}
+				
+				files.add(file);
+			}
+		} finally {
+			rwLock.readLock().unlock();
 		}
 		
 		return files;
 	}
 
+	private String normalizeFolderPath(String path) {
+		if (path.isEmpty()) return path;
+		if (path.charAt(path.length() - 1) != '/') path = path + "/";
+		if (path.charAt(0) == '/') path = path.substring(1);
+		return path;
+	}
+	
+	/*
+	@Override
+	public Collection<String> listFiles(String path, boolean recursive) {
+		Set<String> files = new HashSet<>();
+
+		rwLock.readLock().lock();
+		try {
+			for (int i = 0; i < sources.size(); i++) {
+				files.addAll(sources.get(i).listFiles(path, recursive));
+			}
+		} finally {
+			rwLock.readLock().unlock();
+		}
+		
+		return files;
+	}
+	*/
+
 	@Override
 	public Collection<String> listFolders(String path) {
 		Set<String> folders = new HashSet<>();
 		
-		synchronized (sources) {
+		rwLock.readLock().lock();
+		try {
 			for (int i = 0; i < sources.size(); i++) {
 				folders.addAll(sources.get(i).listFolders(path));
 			}
+		} finally {
+			rwLock.readLock().unlock();
 		}
 		
 		return folders;
@@ -101,7 +161,8 @@ public Collection<String> listFolders(String path) {
 	public void close() throws IOException {
 		IOException exception = null;
 
-		synchronized (sources) {
+		rwLock.writeLock().lock();
+		try {
 			for (FileAccess source : sources) {
 				try {
 					source.close();
@@ -110,6 +171,8 @@ public void close() throws IOException {
 					else exception.addSuppressed(ex);
 				}
 			}
+		} finally {
+			rwLock.writeLock().unlock();
 		}
 		
 		if (exception != null) throw exception;