test NFSFile performance

PerfTest_NFSFile.java

import java.io.File;
import java.io.IOException;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;

import org.eclipse.jgit.api.Git;
import org.eclipse.jgit.api.errors.GitAPIException;
import org.eclipse.jgit.api.errors.JGitInternalException;
import org.eclipse.jgit.errors.ConfigInvalidException;
import org.eclipse.jgit.lib.ConfigConstants;
import org.eclipse.jgit.lib.StoredConfig;
import org.eclipse.jgit.util.FS;

public class PerfTest_NFSFile {
	private static final int NR_OF_FOLDERS = 100;
	private static final int NR_OF_FILES = 1000;

	public static void main(String args[]) throws IOException, GitAPIException, JGitInternalException, ConfigInvalidException {
		long start, end;
		int found;
		Path tmp = Files.createDirectory(Paths.get("tmp_" + System.currentTimeMillis()));
		try (Git git = Git.init().setDirectory(tmp.toFile()).call()) {
			System.out.println("Repo created in " + tmp.toRealPath());

			for (int i = 0; i < NR_OF_FOLDERS; i++) {
				File d = new File(tmp.toFile(), "test" + i);
				d.mkdirs();
				for (int j = 0; j < NR_OF_FILES; j++)
					new File(d, "test" + j).createNewFile();
			}

			found = 0;
			start = System.currentTimeMillis();
			for (int i = 0; i < NR_OF_FOLDERS; i++) {
				File d = new File(tmp.toFile(), "test" + i);
				for (int j = 0; j < NR_OF_FILES; j++) {
					if (new File(d, "test" + j).exists())
						found++;
				}
			}
			end = System.currentTimeMillis();

			System.out.println("Instantiated " + NR_OF_FILES * NR_OF_FOLDERS
					+ " File objects for existing files and checked explicitly for existence (found " + found
					+ " files) in " + (end - start) + " ms.");

			FS fs = git.getRepository().getFS();
			found = 0;
			start = System.currentTimeMillis();
			for (int i = 0; i < NR_OF_FOLDERS; i++) {
				File d = fs.createFile(tmp.toFile(), "test" + i);
				for (int j = 0; j < NR_OF_FILES; j++) {
					if (fs.createFile(d, "test" + j).exists())
						found++;
				}
			}
			end = System.currentTimeMillis();

			System.out.println("Instantiated " + NR_OF_FILES * NR_OF_FOLDERS
					+ " NFSFile objects for existing files and checked explicitly for existence (found " + found
					+ " files) in " + (end - start) + " ms.");
			
			StoredConfig cfg = git.getRepository().getConfig();
			cfg.setBoolean(ConfigConstants.CONFIG_CORE_SECTION, null,
					ConfigConstants.CONFIG_KEY_REFRESHFOLDERSTAT, true);
			cfg.save();
			git.getRepository().getConfig().load();

			found = 0;
			start = System.currentTimeMillis();
			for (int i = 0; i < NR_OF_FOLDERS; i++) {
				File d = fs.createFile(tmp.toFile(), "test" + i);
				for (int j = 0; j < NR_OF_FILES; j++) {
					if (fs.createFile(d, "test" + j).exists())
						found++;
				}
			}
			end = System.currentTimeMillis();

			System.out.println("Instantiated in a repo with CONFIG_KEY_REFRESHFOLDERSTAT set to true " + NR_OF_FILES * NR_OF_FOLDERS
					+ " NFSFile objects for existing files and checked explicitly for existence (found " + found
					+ " files) in " + (end - start) + " ms.");

		} finally {
			Files.walkFileTree(tmp, new SimpleFileVisitor<Path>() {
				public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
					Files.delete(file);
					return FileVisitResult.CONTINUE;
				}

				public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
					Files.delete(dir);
					return FileVisitResult.CONTINUE;
				}
			});
		}
	}
}