org.eclipse.jgit/src/org/eclipse/jgit/api/CloneCommand.java - sop/jgit - Git at Google

 /*
  * Copyright (C) 2011, 2017 Chris Aniszczyk <caniszczyk@gmail.com>
  * and other copyright owners as documented in the project's IP log.
  *
  * This program and the accompanying materials are made available
  * under the terms of the Eclipse Distribution License v1.0 which
  * accompanies this distribution, is reproduced below, and is
  * available at http://www.eclipse.org/org/documents/edl-v10.php
  *
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or
  * without modification, are permitted provided that the following
  * conditions are met:
  *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  *
  * - Redistributions in binary form must reproduce the above
  *   copyright notice, this list of conditions and the following
  *   disclaimer in the documentation and/or other materials provided
  *   with the distribution.
  *
  * - Neither the name of the Eclipse Foundation, Inc. nor the
  *   names of its contributors may be used to endorse or promote
  *   products derived from this software without specific prior
  *   written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 package org.eclipse.jgit.api;

 import java.io.File;
 import java.io.IOException;
 import java.net.URISyntaxException;
 import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;

 import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.api.errors.InvalidRemoteException;
 import org.eclipse.jgit.api.errors.JGitInternalException;
 import org.eclipse.jgit.dircache.DirCache;
 import org.eclipse.jgit.dircache.DirCacheCheckout;
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.lib.AnyObjectId;
 import org.eclipse.jgit.lib.BranchConfig.BranchRebaseMode;
 import org.eclipse.jgit.lib.ConfigConstants;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.NullProgressMonitor;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ProgressMonitor;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.RefUpdate;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevWalk;
 import org.eclipse.jgit.submodule.SubmoduleWalk;
 import org.eclipse.jgit.transport.FetchResult;
 import org.eclipse.jgit.transport.RefSpec;
 import org.eclipse.jgit.transport.RemoteConfig;
 import org.eclipse.jgit.transport.TagOpt;
 import org.eclipse.jgit.transport.URIish;
 import org.eclipse.jgit.util.FS;
 import org.eclipse.jgit.util.FileUtils;

 /**
  * Clone a repository into a new working directory
  *
  * @see <a href="http://www.kernel.org/pub/software/scm/git/docs/git-clone.html"
  *      >Git documentation about Clone</a>
  */
 public class CloneCommand extends TransportCommand<CloneCommand, Git> {

 	private String uri;

 	private File directory;

 	private File gitDir;

 	private boolean bare;

 	private String remote = Constants.DEFAULT_REMOTE_NAME;

 	private String branch = Constants.HEAD;

 	private ProgressMonitor monitor = NullProgressMonitor.INSTANCE;

 	private boolean cloneAllBranches;

 	private boolean cloneSubmodules;

 	private boolean noCheckout;

 	private Collection<String> branchesToClone;

 	private Callback callback;

 	private boolean directoryExistsInitially;

 	private boolean gitDirExistsInitially;

 	/**
 	 * Callback for status of clone operation.
 	 *
 	 * @since 4.8
 	 */
 	public interface Callback {
 		/**
 		 * Notify initialized submodules.
 		 *
 		 * @param submodules
 		 *            the submodules
 		 *
 		 */
 		void initializedSubmodules(Collection<String> submodules);

 		/**
 		 * Notify starting to clone a submodule.
 		 *
 		 * @param path
 		 *            the submodule path
 		 */
 		void cloningSubmodule(String path);

 		/**
 		 * Notify checkout of commit
 		 *
 		 * @param commit
 		 *            the id of the commit being checked out
 		 * @param path
 		 *            the submodule path
 		 */
 		void checkingOut(AnyObjectId commit, String path);
 	}

 	/**
 	 * Create clone command with no repository set
 	 */
 	public CloneCommand() {
 		super(null);
 	}

 	/**
 	 * Executes the {@code Clone} command.
 	 *
 	 * The Git instance returned by this command needs to be closed by the
 	 * caller to free resources held by the underlying {@link Repository}
 	 * instance. It is recommended to call this method as soon as you don't need
 	 * a reference to this {@link Git} instance and the underlying
 	 * {@link Repository} instance anymore.
 	 *
 	 * @return the newly created {@code Git} object with associated repository
 	 * @throws InvalidRemoteException
 	 * @throws org.eclipse.jgit.api.errors.TransportException
 	 * @throws GitAPIException
 	 */
 	@Override
 	public Git call() throws GitAPIException, InvalidRemoteException,
 			org.eclipse.jgit.api.errors.TransportException {
 		URIish u = null;
 		try {
 			u = new URIish(uri);
 			verifyDirectories(u);
 		} catch (URISyntaxException e) {
 			throw new InvalidRemoteException(
 					MessageFormat.format(JGitText.get().invalidURL, uri));
 		}
 		Repository repository = null;
 		FetchResult fetchResult = null;
 		Thread cleanupHook = new Thread(() -> cleanup());
 		Runtime.getRuntime().addShutdownHook(cleanupHook);
 		try {
 			repository = init();
 			fetchResult = fetch(repository, u);
 		} catch (IOException ioe) {
 			if (repository != null) {
 				repository.close();
 			}
 			cleanup();
 			throw new JGitInternalException(ioe.getMessage(), ioe);
 		} catch (URISyntaxException e) {
 			if (repository != null) {
 				repository.close();
 			}
 			cleanup();
 			throw new InvalidRemoteException(MessageFormat.format(
 					JGitText.get().invalidRemote, remote));
 		} catch (GitAPIException | RuntimeException e) {
 			if (repository != null) {
 				repository.close();
 			}
 			cleanup();
 			throw e;
 		} finally {
 			Runtime.getRuntime().removeShutdownHook(cleanupHook);
 		}
 		if (!noCheckout) {
 			try {
 				checkout(repository, fetchResult);
 			} catch (IOException ioe) {
 				repository.close();
 				throw new JGitInternalException(ioe.getMessage(), ioe);
 			} catch (GitAPIException | RuntimeException e) {
 				repository.close();
 				throw e;
 			}
 		}
 		return new Git(repository, true);
 	}

 	private static boolean isNonEmptyDirectory(File dir) {
 		if (dir != null && dir.exists()) {
 			File[] files = dir.listFiles();
 			return files != null && files.length != 0;
 		}
 		return false;
 	}

 	private void verifyDirectories(URIish u) {
 		if (directory == null && gitDir == null) {
 			directory = new File(u.getHumanishName(), Constants.DOT_GIT);
 		}
 		directoryExistsInitially = directory != null && directory.exists();
 		gitDirExistsInitially = gitDir != null && gitDir.exists();
 		validateDirs(directory, gitDir, bare);
 		if (isNonEmptyDirectory(directory)) {
 			throw new JGitInternalException(MessageFormat.format(
 					JGitText.get().cloneNonEmptyDirectory, directory.getName()));
 		}
 		if (isNonEmptyDirectory(gitDir)) {
 			throw new JGitInternalException(MessageFormat.format(
 					JGitText.get().cloneNonEmptyDirectory, gitDir.getName()));
 		}
 	}

 	private Repository init() throws GitAPIException {
 		InitCommand command = Git.init();
 		command.setBare(bare);
 		if (directory != null) {
 			command.setDirectory(directory);
 		}
 		if (gitDir != null) {
 			command.setGitDir(gitDir);
 		}
 		return command.call().getRepository();
 	}

 	private FetchResult fetch(Repository clonedRepo, URIish u)
 			throws URISyntaxException,
 			org.eclipse.jgit.api.errors.TransportException, IOException,
 			GitAPIException {
 		// create the remote config and save it
 		RemoteConfig config = new RemoteConfig(clonedRepo.getConfig(), remote);
 		config.addURI(u);

 		final String dst = (bare ? Constants.R_HEADS : Constants.R_REMOTES
 				+ config.getName() + "/") + "*"; //$NON-NLS-1$//$NON-NLS-2$
 		RefSpec refSpec = new RefSpec();
 		refSpec = refSpec.setForceUpdate(true);
 		refSpec = refSpec.setSourceDestination(Constants.R_HEADS + "*", dst); //$NON-NLS-1$

 		config.addFetchRefSpec(refSpec);
 		config.update(clonedRepo.getConfig());

 		clonedRepo.getConfig().save();

 		// run the fetch command
 		FetchCommand command = new FetchCommand(clonedRepo);
 		command.setRemote(remote);
 		command.setProgressMonitor(monitor);
 		command.setTagOpt(TagOpt.FETCH_TAGS);
 		configure(command);

 		List<RefSpec> specs = calculateRefSpecs(dst);
 		command.setRefSpecs(specs);

 		return command.call();
 	}

 	private List<RefSpec> calculateRefSpecs(final String dst) {
 		RefSpec wcrs = new RefSpec();
 		wcrs = wcrs.setForceUpdate(true);
 		wcrs = wcrs.setSourceDestination(Constants.R_HEADS + "*", dst); //$NON-NLS-1$
 		List<RefSpec> specs = new ArrayList<>();
 		if (cloneAllBranches)
 			specs.add(wcrs);
 		else if (branchesToClone != null
 				&& branchesToClone.size() > 0) {
 			for (final String selectedRef : branchesToClone)
 				if (wcrs.matchSource(selectedRef))
 					specs.add(wcrs.expandFromSource(selectedRef));
 		}
 		return specs;
 	}

 	private void checkout(Repository clonedRepo, FetchResult result)
 			throws MissingObjectException, IncorrectObjectTypeException,
 			IOException, GitAPIException {

 		Ref head = null;
 		if (branch.equals(Constants.HEAD)) {
 			Ref foundBranch = findBranchToCheckout(result);
 			if (foundBranch != null)
 				head = foundBranch;
 		}
 		if (head == null) {
 			head = result.getAdvertisedRef(branch);
 			if (head == null)
 				head = result.getAdvertisedRef(Constants.R_HEADS + branch);
 			if (head == null)
 				head = result.getAdvertisedRef(Constants.R_TAGS + branch);
 		}

 		if (head == null || head.getObjectId() == null)
 			return; // TODO throw exception?

 		if (head.getName().startsWith(Constants.R_HEADS)) {
 			final RefUpdate newHead = clonedRepo.updateRef(Constants.HEAD);
 			newHead.disableRefLog();
 			newHead.link(head.getName());
 			addMergeConfig(clonedRepo, head);
 		}

 		final RevCommit commit = parseCommit(clonedRepo, head);

 		boolean detached = !head.getName().startsWith(Constants.R_HEADS);
 		RefUpdate u = clonedRepo.updateRef(Constants.HEAD, detached);
 		u.setNewObjectId(commit.getId());
 		u.forceUpdate();

 		if (!bare) {
 			DirCache dc = clonedRepo.lockDirCache();
 			DirCacheCheckout co = new DirCacheCheckout(clonedRepo, dc,
 					commit.getTree());
 			co.checkout();
 			if (cloneSubmodules)
 				cloneSubmodules(clonedRepo);
 		}
 	}

 	private void cloneSubmodules(Repository clonedRepo) throws IOException,
 			GitAPIException {
 		SubmoduleInitCommand init = new SubmoduleInitCommand(clonedRepo);
 		Collection<String> submodules = init.call();
 		if (submodules.isEmpty()) {
 			return;
 		}
 		if (callback != null) {
 			callback.initializedSubmodules(submodules);
 		}

 		SubmoduleUpdateCommand update = new SubmoduleUpdateCommand(clonedRepo);
 		configure(update);
 		update.setProgressMonitor(monitor);
 		update.setCallback(callback);
 		if (!update.call().isEmpty()) {
 			SubmoduleWalk walk = SubmoduleWalk.forIndex(clonedRepo);
 			while (walk.next()) {
 				Repository subRepo = walk.getRepository();
 				if (subRepo != null) {
 					try {
 						cloneSubmodules(subRepo);
 					} finally {
 						subRepo.close();
 					}
 				}
 			}
 		}
 	}

 	private Ref findBranchToCheckout(FetchResult result) {
 		final Ref idHEAD = result.getAdvertisedRef(Constants.HEAD);
 		ObjectId headId = idHEAD != null ? idHEAD.getObjectId() : null;
 		if (headId == null) {
 			return null;
 		}

 		Ref master = result.getAdvertisedRef(Constants.R_HEADS
 				+ Constants.MASTER);
 		ObjectId objectId = master != null ? master.getObjectId() : null;
 		if (headId.equals(objectId)) {
 			return master;
 		}

 		Ref foundBranch = null;
 		for (final Ref r : result.getAdvertisedRefs()) {
 			final String n = r.getName();
 			if (!n.startsWith(Constants.R_HEADS))
 				continue;
 			if (headId.equals(r.getObjectId())) {
 				foundBranch = r;
 				break;
 			}
 		}
 		return foundBranch;
 	}

 	private void addMergeConfig(Repository clonedRepo, Ref head)
 			throws IOException {
 		String branchName = Repository.shortenRefName(head.getName());
 		clonedRepo.getConfig().setString(ConfigConstants.CONFIG_BRANCH_SECTION,
 				branchName, ConfigConstants.CONFIG_KEY_REMOTE, remote);
 		clonedRepo.getConfig().setString(ConfigConstants.CONFIG_BRANCH_SECTION,
 				branchName, ConfigConstants.CONFIG_KEY_MERGE, head.getName());
 		String autosetupRebase = clonedRepo.getConfig().getString(
 				ConfigConstants.CONFIG_BRANCH_SECTION, null,
 				ConfigConstants.CONFIG_KEY_AUTOSETUPREBASE);
 		if (ConfigConstants.CONFIG_KEY_ALWAYS.equals(autosetupRebase)
 				|| ConfigConstants.CONFIG_KEY_REMOTE.equals(autosetupRebase))
 			clonedRepo.getConfig().setEnum(
 					ConfigConstants.CONFIG_BRANCH_SECTION, branchName,
 					ConfigConstants.CONFIG_KEY_REBASE, BranchRebaseMode.REBASE);
 		clonedRepo.getConfig().save();
 	}

 	private RevCommit parseCommit(final Repository clonedRepo, final Ref ref)
 			throws MissingObjectException, IncorrectObjectTypeException,
 			IOException {
 		final RevCommit commit;
 		try (final RevWalk rw = new RevWalk(clonedRepo)) {
 			commit = rw.parseCommit(ref.getObjectId());
 		}
 		return commit;
 	}

 	/**
 	 * @param uri
 	 *            the URI to clone from, or {@code null} to unset the URI.
 	 *            The URI must be set before {@link #call} is called.
 	 * @return this instance
 	 */
 	public CloneCommand setURI(String uri) {
 		this.uri = uri;
 		return this;
 	}

 	/**
 	 * The optional directory associated with the clone operation. If the
 	 * directory isn't set, a name associated with the source uri will be used.
 	 *
 	 * @see URIish#getHumanishName()
 	 *
 	 * @param directory
 	 *            the directory to clone to, or {@code null} if the directory
 	 *            name should be taken from the source uri
 	 * @return this instance
 	 * @throws IllegalStateException
 	 *             if the combination of directory, gitDir and bare is illegal.
 	 *             E.g. if for a non-bare repository directory and gitDir point
 	 *             to the same directory of if for a bare repository both
 	 *             directory and gitDir are specified
 	 */
 	public CloneCommand setDirectory(File directory) {
 		validateDirs(directory, gitDir, bare);
 		this.directory = directory;
 		return this;
 	}

 	/**
 	 * @param gitDir
 	 *            the repository meta directory, or {@code null} to choose one
 	 *            automatically at clone time
 	 * @return this instance
 	 * @throws IllegalStateException
 	 *             if the combination of directory, gitDir and bare is illegal.
 	 *             E.g. if for a non-bare repository directory and gitDir point
 	 *             to the same directory of if for a bare repository both
 	 *             directory and gitDir are specified
 	 * @since 3.6
 	 */
 	public CloneCommand setGitDir(File gitDir) {
 		validateDirs(directory, gitDir, bare);
 		this.gitDir = gitDir;
 		return this;
 	}

 	/**
 	 * @param bare
 	 *            whether the cloned repository is bare or not
 	 * @return this instance
 	 * @throws IllegalStateException
 	 *             if the combination of directory, gitDir and bare is illegal.
 	 *             E.g. if for a non-bare repository directory and gitDir point
 	 *             to the same directory of if for a bare repository both
 	 *             directory and gitDir are specified
 	 */
 	public CloneCommand setBare(boolean bare) throws IllegalStateException {
 		validateDirs(directory, gitDir, bare);
 		this.bare = bare;
 		return this;
 	}

 	/**
 	 * The remote name used to keep track of the upstream repository for the
 	 * clone operation. If no remote name is set, the default value of
 	 * <code>Constants.DEFAULT_REMOTE_NAME</code> will be used.
 	 *
 	 * @see Constants#DEFAULT_REMOTE_NAME
 	 * @param remote
 	 *            name that keeps track of the upstream repository.
 	 *            {@code null} means to use DEFAULT_REMOTE_NAME.
 	 * @return this instance
 	 */
 	public CloneCommand setRemote(String remote) {
 		if (remote == null) {
 			remote = Constants.DEFAULT_REMOTE_NAME;
 		}
 		this.remote = remote;
 		return this;
 	}

 	/**
 	 * @param branch
 	 *            the initial branch to check out when cloning the repository.
 	 *            Can be specified as ref name (<code>refs/heads/master</code>),
 	 *            branch name (<code>master</code>) or tag name (<code>v1.2.3</code>).
 	 *            The default is to use the branch pointed to by the cloned
 	 *            repository's HEAD and can be requested by passing {@code null}
 	 *            or <code>HEAD</code>.
 	 * @return this instance
 	 */
 	public CloneCommand setBranch(String branch) {
 		if (branch == null) {
 			branch = Constants.HEAD;
 		}
 		this.branch = branch;
 		return this;
 	}

 	/**
 	 * The progress monitor associated with the clone operation. By default,
 	 * this is set to <code>NullProgressMonitor</code>
 	 *
 	 * @see NullProgressMonitor
 	 *
 	 * @param monitor
 	 * @return {@code this}
 	 */
 	public CloneCommand setProgressMonitor(ProgressMonitor monitor) {
 		if (monitor == null) {
 			monitor = NullProgressMonitor.INSTANCE;
 		}
 		this.monitor = monitor;
 		return this;
 	}

 	/**
 	 * @param cloneAllBranches
 	 *            true when all branches have to be fetched (indicates wildcard
 	 *            in created fetch refspec), false otherwise.
 	 * @return {@code this}
 	 */
 	public CloneCommand setCloneAllBranches(boolean cloneAllBranches) {
 		this.cloneAllBranches = cloneAllBranches;
 		return this;
 	}

 	/**
 	 * @param cloneSubmodules
 	 *            true to initialize and update submodules. Ignored when
 	 *            {@link #setBare(boolean)} is set to true.
 	 * @return {@code this}
 	 */
 	public CloneCommand setCloneSubmodules(boolean cloneSubmodules) {
 		this.cloneSubmodules = cloneSubmodules;
 		return this;
 	}

 	/**
 	 * @param branchesToClone
 	 *            collection of branches to clone. Ignored when allSelected is
 	 *            true. Must be specified as full ref names (e.g.
 	 *            <code>refs/heads/master</code>).
 	 * @return {@code this}
 	 */
 	public CloneCommand setBranchesToClone(Collection<String> branchesToClone) {
 		this.branchesToClone = branchesToClone;
 		return this;
 	}

 	/**
 	 * @param noCheckout
 	 *            if set to <code>true</code> no branch will be checked out
 	 *            after the clone. This enhances performance of the clone
 	 *            command when there is no need for a checked out branch.
 	 * @return {@code this}
 	 */
 	public CloneCommand setNoCheckout(boolean noCheckout) {
 		this.noCheckout = noCheckout;
 		return this;
 	}

 	/**
 	 * Register a progress callback.
 	 *
 	 * @param callback
 	 *            the callback
 	 * @return {@code this}
 	 * @since 4.8
 	 */
 	public CloneCommand setCallback(Callback callback) {
 		this.callback = callback;
 		return this;
 	}

 	private static void validateDirs(File directory, File gitDir, boolean bare)
 			throws IllegalStateException {
 		if (directory != null) {
 			if (directory.exists() && !directory.isDirectory()) {
 				throw new IllegalStateException(MessageFormat.format(
 						JGitText.get().initFailedDirIsNoDirectory, directory));
 			}
 			if (gitDir != null && gitDir.exists() && !gitDir.isDirectory()) {
 				throw new IllegalStateException(MessageFormat.format(
 						JGitText.get().initFailedGitDirIsNoDirectory,
 						gitDir));
 			}
 			if (bare) {
 				if (gitDir != null && !gitDir.equals(directory))
 					throw new IllegalStateException(MessageFormat.format(
 							JGitText.get().initFailedBareRepoDifferentDirs,
 							gitDir, directory));
 			} else {
 				if (gitDir != null && gitDir.equals(directory))
 					throw new IllegalStateException(MessageFormat.format(
 							JGitText.get().initFailedNonBareRepoSameDirs,
 							gitDir, directory));
 			}
 		}
 	}

 	private void cleanup() {
 		try {
 			if (directory != null) {
 				if (!directoryExistsInitially) {
 					FileUtils.delete(directory, FileUtils.RECURSIVE
 							| FileUtils.SKIP_MISSING | FileUtils.IGNORE_ERRORS);
 				} else {
 					deleteChildren(directory);
 				}
 			}
 			if (gitDir != null) {
 				if (!gitDirExistsInitially) {
 					FileUtils.delete(gitDir, FileUtils.RECURSIVE
 							| FileUtils.SKIP_MISSING | FileUtils.IGNORE_ERRORS);
 				} else {
 					deleteChildren(directory);
 				}
 			}
 		} catch (IOException e) {
 			// Ignore; this is a best-effort cleanup in error cases, and
 			// IOException should not be raised anyway
 		}
 	}

 	private void deleteChildren(File file) throws IOException {
 		if (!FS.DETECTED.isDirectory(file)) {
 			return;
 		}
 		for (File child : file.listFiles()) {
 			FileUtils.delete(child, FileUtils.RECURSIVE | FileUtils.SKIP_MISSING
 					| FileUtils.IGNORE_ERRORS);
 		}
 	}
 }
	/*
	* Copyright (C) 2011, 2017 Chris Aniszczyk <caniszczyk@gmail.com>
	* and other copyright owners as documented in the project's IP log.
	*
	* This program and the accompanying materials are made available
	* under the terms of the Eclipse Distribution License v1.0 which
	* accompanies this distribution, is reproduced below, and is
	* available at http://www.eclipse.org/org/documents/edl-v10.php
	*
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or
	* without modification, are permitted provided that the following
	* conditions are met:
	*
	* - Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	*
	* - Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following
	* disclaimer in the documentation and/or other materials provided
	* with the distribution.
	*
	* - Neither the name of the Eclipse Foundation, Inc. nor the
	* names of its contributors may be used to endorse or promote
	* products derived from this software without specific prior
	* written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
	* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
	* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
	* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
	* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/
	package org.eclipse.jgit.api;

	import java.io.File;
	import java.io.IOException;
	import java.net.URISyntaxException;
	import java.text.MessageFormat;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.List;

	import org.eclipse.jgit.api.errors.GitAPIException;
	import org.eclipse.jgit.api.errors.InvalidRemoteException;
	import org.eclipse.jgit.api.errors.JGitInternalException;
	import org.eclipse.jgit.dircache.DirCache;
	import org.eclipse.jgit.dircache.DirCacheCheckout;
	import org.eclipse.jgit.errors.IncorrectObjectTypeException;
	import org.eclipse.jgit.errors.MissingObjectException;
	import org.eclipse.jgit.internal.JGitText;
	import org.eclipse.jgit.lib.AnyObjectId;
	import org.eclipse.jgit.lib.BranchConfig.BranchRebaseMode;
	import org.eclipse.jgit.lib.ConfigConstants;
	import org.eclipse.jgit.lib.Constants;
	import org.eclipse.jgit.lib.NullProgressMonitor;
	import org.eclipse.jgit.lib.ObjectId;
	import org.eclipse.jgit.lib.ProgressMonitor;
	import org.eclipse.jgit.lib.Ref;
	import org.eclipse.jgit.lib.RefUpdate;
	import org.eclipse.jgit.lib.Repository;
	import org.eclipse.jgit.revwalk.RevCommit;
	import org.eclipse.jgit.revwalk.RevWalk;
	import org.eclipse.jgit.submodule.SubmoduleWalk;
	import org.eclipse.jgit.transport.FetchResult;
	import org.eclipse.jgit.transport.RefSpec;
	import org.eclipse.jgit.transport.RemoteConfig;
	import org.eclipse.jgit.transport.TagOpt;
	import org.eclipse.jgit.transport.URIish;
	import org.eclipse.jgit.util.FS;
	import org.eclipse.jgit.util.FileUtils;

	/**
	* Clone a repository into a new working directory
	*
	* @see <a href="http://www.kernel.org/pub/software/scm/git/docs/git-clone.html"
	* >Git documentation about Clone</a>
	*/
	public class CloneCommand extends TransportCommand<CloneCommand, Git> {

	private String uri;

	private File directory;

	private File gitDir;

	private boolean bare;

	private String remote = Constants.DEFAULT_REMOTE_NAME;

	private String branch = Constants.HEAD;

	private ProgressMonitor monitor = NullProgressMonitor.INSTANCE;

	private boolean cloneAllBranches;

	private boolean cloneSubmodules;

	private boolean noCheckout;

	private Collection<String> branchesToClone;

	private Callback callback;

	private boolean directoryExistsInitially;

	private boolean gitDirExistsInitially;

	/**
	* Callback for status of clone operation.
	*
	* @since 4.8
	*/
	public interface Callback {
	/**
	* Notify initialized submodules.
	*
	* @param submodules
	* the submodules
	*
	*/
	void initializedSubmodules(Collection<String> submodules);

	/**
	* Notify starting to clone a submodule.
	*
	* @param path
	* the submodule path
	*/
	void cloningSubmodule(String path);

	/**
	* Notify checkout of commit
	*
	* @param commit
	* the id of the commit being checked out
	* @param path
	* the submodule path
	*/
	void checkingOut(AnyObjectId commit, String path);
	}

	/**
	* Create clone command with no repository set
	*/
	public CloneCommand() {
	super(null);
	}

	/**
	* Executes the {@code Clone} command.
	*
	* The Git instance returned by this command needs to be closed by the
	* caller to free resources held by the underlying {@link Repository}
	* instance. It is recommended to call this method as soon as you don't need
	* a reference to this {@link Git} instance and the underlying
	* {@link Repository} instance anymore.
	*
	* @return the newly created {@code Git} object with associated repository
	* @throws InvalidRemoteException
	* @throws org.eclipse.jgit.api.errors.TransportException
	* @throws GitAPIException
	*/
	@Override
	public Git call() throws GitAPIException, InvalidRemoteException,
	org.eclipse.jgit.api.errors.TransportException {
	URIish u = null;
	try {
	u = new URIish(uri);
	verifyDirectories(u);
	} catch (URISyntaxException e) {
	throw new InvalidRemoteException(
	MessageFormat.format(JGitText.get().invalidURL, uri));
	}
	Repository repository = null;
	FetchResult fetchResult = null;
	Thread cleanupHook = new Thread(() -> cleanup());
	Runtime.getRuntime().addShutdownHook(cleanupHook);
	try {
	repository = init();
	fetchResult = fetch(repository, u);
	} catch (IOException ioe) {
	if (repository != null) {
	repository.close();
	}
	cleanup();
	throw new JGitInternalException(ioe.getMessage(), ioe);
	} catch (URISyntaxException e) {
	if (repository != null) {
	repository.close();
	}
	cleanup();
	throw new InvalidRemoteException(MessageFormat.format(
	JGitText.get().invalidRemote, remote));
	} catch (GitAPIException \| RuntimeException e) {
	if (repository != null) {
	repository.close();
	}
	cleanup();
	throw e;
	} finally {
	Runtime.getRuntime().removeShutdownHook(cleanupHook);
	}
	if (!noCheckout) {
	try {
	checkout(repository, fetchResult);
	} catch (IOException ioe) {
	repository.close();
	throw new JGitInternalException(ioe.getMessage(), ioe);
	} catch (GitAPIException \| RuntimeException e) {
	repository.close();
	throw e;
	}
	}
	return new Git(repository, true);
	}

	private static boolean isNonEmptyDirectory(File dir) {
	if (dir != null && dir.exists()) {
	File[] files = dir.listFiles();
	return files != null && files.length != 0;
	}
	return false;
	}

	private void verifyDirectories(URIish u) {
	if (directory == null && gitDir == null) {
	directory = new File(u.getHumanishName(), Constants.DOT_GIT);
	}
	directoryExistsInitially = directory != null && directory.exists();
	gitDirExistsInitially = gitDir != null && gitDir.exists();
	validateDirs(directory, gitDir, bare);
	if (isNonEmptyDirectory(directory)) {
	throw new JGitInternalException(MessageFormat.format(
	JGitText.get().cloneNonEmptyDirectory, directory.getName()));
	}
	if (isNonEmptyDirectory(gitDir)) {
	throw new JGitInternalException(MessageFormat.format(
	JGitText.get().cloneNonEmptyDirectory, gitDir.getName()));
	}
	}

	private Repository init() throws GitAPIException {
	InitCommand command = Git.init();
	command.setBare(bare);
	if (directory != null) {
	command.setDirectory(directory);
	}
	if (gitDir != null) {
	command.setGitDir(gitDir);
	}
	return command.call().getRepository();
	}

	private FetchResult fetch(Repository clonedRepo, URIish u)
	throws URISyntaxException,
	org.eclipse.jgit.api.errors.TransportException, IOException,
	GitAPIException {
	// create the remote config and save it
	RemoteConfig config = new RemoteConfig(clonedRepo.getConfig(), remote);
	config.addURI(u);

	final String dst = (bare ? Constants.R_HEADS : Constants.R_REMOTES
	+ config.getName() + "/") + "*"; //$NON-NLS-1$//$NON-NLS-2$
	RefSpec refSpec = new RefSpec();
	refSpec = refSpec.setForceUpdate(true);
	refSpec = refSpec.setSourceDestination(Constants.R_HEADS + "*", dst); //$NON-NLS-1$

	config.addFetchRefSpec(refSpec);
	config.update(clonedRepo.getConfig());

	clonedRepo.getConfig().save();

	// run the fetch command
	FetchCommand command = new FetchCommand(clonedRepo);
	command.setRemote(remote);
	command.setProgressMonitor(monitor);
	command.setTagOpt(TagOpt.FETCH_TAGS);
	configure(command);

	List<RefSpec> specs = calculateRefSpecs(dst);
	command.setRefSpecs(specs);

	return command.call();
	}

	private List<RefSpec> calculateRefSpecs(final String dst) {
	RefSpec wcrs = new RefSpec();
	wcrs = wcrs.setForceUpdate(true);
	wcrs = wcrs.setSourceDestination(Constants.R_HEADS + "*", dst); //$NON-NLS-1$
	List<RefSpec> specs = new ArrayList<>();
	if (cloneAllBranches)
	specs.add(wcrs);
	else if (branchesToClone != null
	&& branchesToClone.size() > 0) {
	for (final String selectedRef : branchesToClone)
	if (wcrs.matchSource(selectedRef))
	specs.add(wcrs.expandFromSource(selectedRef));
	}
	return specs;
	}

	private void checkout(Repository clonedRepo, FetchResult result)
	throws MissingObjectException, IncorrectObjectTypeException,
	IOException, GitAPIException {

	Ref head = null;
	if (branch.equals(Constants.HEAD)) {
	Ref foundBranch = findBranchToCheckout(result);
	if (foundBranch != null)
	head = foundBranch;
	}
	if (head == null) {
	head = result.getAdvertisedRef(branch);
	if (head == null)
	head = result.getAdvertisedRef(Constants.R_HEADS + branch);
	if (head == null)
	head = result.getAdvertisedRef(Constants.R_TAGS + branch);
	}

	if (head == null \|\| head.getObjectId() == null)
	return; // TODO throw exception?

	if (head.getName().startsWith(Constants.R_HEADS)) {
	final RefUpdate newHead = clonedRepo.updateRef(Constants.HEAD);
	newHead.disableRefLog();
	newHead.link(head.getName());
	addMergeConfig(clonedRepo, head);
	}

	final RevCommit commit = parseCommit(clonedRepo, head);

	boolean detached = !head.getName().startsWith(Constants.R_HEADS);
	RefUpdate u = clonedRepo.updateRef(Constants.HEAD, detached);
	u.setNewObjectId(commit.getId());
	u.forceUpdate();

	if (!bare) {
	DirCache dc = clonedRepo.lockDirCache();
	DirCacheCheckout co = new DirCacheCheckout(clonedRepo, dc,
	commit.getTree());
	co.checkout();
	if (cloneSubmodules)
	cloneSubmodules(clonedRepo);
	}
	}

	private void cloneSubmodules(Repository clonedRepo) throws IOException,
	GitAPIException {
	SubmoduleInitCommand init = new SubmoduleInitCommand(clonedRepo);
	Collection<String> submodules = init.call();
	if (submodules.isEmpty()) {
	return;
	}
	if (callback != null) {
	callback.initializedSubmodules(submodules);
	}

	SubmoduleUpdateCommand update = new SubmoduleUpdateCommand(clonedRepo);
	configure(update);
	update.setProgressMonitor(monitor);
	update.setCallback(callback);
	if (!update.call().isEmpty()) {
	SubmoduleWalk walk = SubmoduleWalk.forIndex(clonedRepo);
	while (walk.next()) {
	Repository subRepo = walk.getRepository();
	if (subRepo != null) {
	try {
	cloneSubmodules(subRepo);
	} finally {
	subRepo.close();
	}
	}
	}
	}
	}

	private Ref findBranchToCheckout(FetchResult result) {
	final Ref idHEAD = result.getAdvertisedRef(Constants.HEAD);
	ObjectId headId = idHEAD != null ? idHEAD.getObjectId() : null;
	if (headId == null) {
	return null;
	}

	Ref master = result.getAdvertisedRef(Constants.R_HEADS
	+ Constants.MASTER);
	ObjectId objectId = master != null ? master.getObjectId() : null;
	if (headId.equals(objectId)) {
	return master;
	}

	Ref foundBranch = null;
	for (final Ref r : result.getAdvertisedRefs()) {
	final String n = r.getName();
	if (!n.startsWith(Constants.R_HEADS))
	continue;
	if (headId.equals(r.getObjectId())) {
	foundBranch = r;
	break;
	}
	}
	return foundBranch;
	}

	private void addMergeConfig(Repository clonedRepo, Ref head)
	throws IOException {
	String branchName = Repository.shortenRefName(head.getName());
	clonedRepo.getConfig().setString(ConfigConstants.CONFIG_BRANCH_SECTION,
	branchName, ConfigConstants.CONFIG_KEY_REMOTE, remote);
	clonedRepo.getConfig().setString(ConfigConstants.CONFIG_BRANCH_SECTION,
	branchName, ConfigConstants.CONFIG_KEY_MERGE, head.getName());
	String autosetupRebase = clonedRepo.getConfig().getString(
	ConfigConstants.CONFIG_BRANCH_SECTION, null,
	ConfigConstants.CONFIG_KEY_AUTOSETUPREBASE);
	if (ConfigConstants.CONFIG_KEY_ALWAYS.equals(autosetupRebase)
	\|\| ConfigConstants.CONFIG_KEY_REMOTE.equals(autosetupRebase))
	clonedRepo.getConfig().setEnum(
	ConfigConstants.CONFIG_BRANCH_SECTION, branchName,
	ConfigConstants.CONFIG_KEY_REBASE, BranchRebaseMode.REBASE);
	clonedRepo.getConfig().save();
	}

	private RevCommit parseCommit(final Repository clonedRepo, final Ref ref)
	throws MissingObjectException, IncorrectObjectTypeException,
	IOException {
	final RevCommit commit;
	try (final RevWalk rw = new RevWalk(clonedRepo)) {
	commit = rw.parseCommit(ref.getObjectId());
	}
	return commit;
	}

	/**
	* @param uri
	* the URI to clone from, or {@code null} to unset the URI.
	* The URI must be set before {@link #call} is called.
	* @return this instance
	*/
	public CloneCommand setURI(String uri) {
	this.uri = uri;
	return this;
	}

	/**
	* The optional directory associated with the clone operation. If the
	* directory isn't set, a name associated with the source uri will be used.
	*
	* @see URIish#getHumanishName()
	*
	* @param directory
	* the directory to clone to, or {@code null} if the directory
	* name should be taken from the source uri
	* @return this instance
	* @throws IllegalStateException
	* if the combination of directory, gitDir and bare is illegal.
	* E.g. if for a non-bare repository directory and gitDir point
	* to the same directory of if for a bare repository both
	* directory and gitDir are specified
	*/
	public CloneCommand setDirectory(File directory) {
	validateDirs(directory, gitDir, bare);
	this.directory = directory;
	return this;
	}

	/**
	* @param gitDir
	* the repository meta directory, or {@code null} to choose one
	* automatically at clone time
	* @return this instance
	* @throws IllegalStateException
	* if the combination of directory, gitDir and bare is illegal.
	* E.g. if for a non-bare repository directory and gitDir point
	* to the same directory of if for a bare repository both
	* directory and gitDir are specified
	* @since 3.6
	*/
	public CloneCommand setGitDir(File gitDir) {
	validateDirs(directory, gitDir, bare);
	this.gitDir = gitDir;
	return this;
	}

	/**
	* @param bare
	* whether the cloned repository is bare or not
	* @return this instance
	* @throws IllegalStateException
	* if the combination of directory, gitDir and bare is illegal.
	* E.g. if for a non-bare repository directory and gitDir point
	* to the same directory of if for a bare repository both
	* directory and gitDir are specified
	*/
	public CloneCommand setBare(boolean bare) throws IllegalStateException {
	validateDirs(directory, gitDir, bare);
	this.bare = bare;
	return this;
	}

	/**
	* The remote name used to keep track of the upstream repository for the
	* clone operation. If no remote name is set, the default value of
	* <code>Constants.DEFAULT_REMOTE_NAME</code> will be used.
	*
	* @see Constants#DEFAULT_REMOTE_NAME
	* @param remote
	* name that keeps track of the upstream repository.
	* {@code null} means to use DEFAULT_REMOTE_NAME.
	* @return this instance
	*/
	public CloneCommand setRemote(String remote) {
	if (remote == null) {
	remote = Constants.DEFAULT_REMOTE_NAME;
	}
	this.remote = remote;
	return this;
	}

	/**
	* @param branch
	* the initial branch to check out when cloning the repository.
	* Can be specified as ref name (<code>refs/heads/master</code>),
	* branch name (<code>master</code>) or tag name (<code>v1.2.3</code>).
	* The default is to use the branch pointed to by the cloned
	* repository's HEAD and can be requested by passing {@code null}
	* or <code>HEAD</code>.
	* @return this instance
	*/
	public CloneCommand setBranch(String branch) {
	if (branch == null) {
	branch = Constants.HEAD;
	}
	this.branch = branch;
	return this;
	}

	/**
	* The progress monitor associated with the clone operation. By default,
	* this is set to <code>NullProgressMonitor</code>
	*
	* @see NullProgressMonitor
	*
	* @param monitor
	* @return {@code this}
	*/
	public CloneCommand setProgressMonitor(ProgressMonitor monitor) {
	if (monitor == null) {
	monitor = NullProgressMonitor.INSTANCE;
	}
	this.monitor = monitor;
	return this;
	}

	/**
	* @param cloneAllBranches
	* true when all branches have to be fetched (indicates wildcard
	* in created fetch refspec), false otherwise.
	* @return {@code this}
	*/
	public CloneCommand setCloneAllBranches(boolean cloneAllBranches) {
	this.cloneAllBranches = cloneAllBranches;
	return this;
	}

	/**
	* @param cloneSubmodules
	* true to initialize and update submodules. Ignored when
	* {@link #setBare(boolean)} is set to true.
	* @return {@code this}
	*/
	public CloneCommand setCloneSubmodules(boolean cloneSubmodules) {
	this.cloneSubmodules = cloneSubmodules;
	return this;
	}

	/**
	* @param branchesToClone
	* collection of branches to clone. Ignored when allSelected is
	* true. Must be specified as full ref names (e.g.
	* <code>refs/heads/master</code>).
	* @return {@code this}
	*/
	public CloneCommand setBranchesToClone(Collection<String> branchesToClone) {
	this.branchesToClone = branchesToClone;
	return this;
	}

	/**
	* @param noCheckout
	* if set to <code>true</code> no branch will be checked out
	* after the clone. This enhances performance of the clone
	* command when there is no need for a checked out branch.
	* @return {@code this}
	*/
	public CloneCommand setNoCheckout(boolean noCheckout) {
	this.noCheckout = noCheckout;
	return this;
	}

	/**
	* Register a progress callback.
	*
	* @param callback
	* the callback
	* @return {@code this}
	* @since 4.8
	*/
	public CloneCommand setCallback(Callback callback) {
	this.callback = callback;
	return this;
	}

	private static void validateDirs(File directory, File gitDir, boolean bare)
	throws IllegalStateException {
	if (directory != null) {
	if (directory.exists() && !directory.isDirectory()) {
	throw new IllegalStateException(MessageFormat.format(
	JGitText.get().initFailedDirIsNoDirectory, directory));
	}
	if (gitDir != null && gitDir.exists() && !gitDir.isDirectory()) {
	throw new IllegalStateException(MessageFormat.format(
	JGitText.get().initFailedGitDirIsNoDirectory,
	gitDir));
	}
	if (bare) {
	if (gitDir != null && !gitDir.equals(directory))
	throw new IllegalStateException(MessageFormat.format(
	JGitText.get().initFailedBareRepoDifferentDirs,
	gitDir, directory));
	} else {
	if (gitDir != null && gitDir.equals(directory))
	throw new IllegalStateException(MessageFormat.format(
	JGitText.get().initFailedNonBareRepoSameDirs,
	gitDir, directory));
	}
	}
	}

	private void cleanup() {
	try {
	if (directory != null) {
	if (!directoryExistsInitially) {
	FileUtils.delete(directory, FileUtils.RECURSIVE
	\| FileUtils.SKIP_MISSING \| FileUtils.IGNORE_ERRORS);
	} else {
	deleteChildren(directory);
	}
	}
	if (gitDir != null) {
	if (!gitDirExistsInitially) {
	FileUtils.delete(gitDir, FileUtils.RECURSIVE
	\| FileUtils.SKIP_MISSING \| FileUtils.IGNORE_ERRORS);
	} else {
	deleteChildren(directory);
	}
	}
	} catch (IOException e) {
	// Ignore; this is a best-effort cleanup in error cases, and
	// IOException should not be raised anyway
	}
	}

	private void deleteChildren(File file) throws IOException {
	if (!FS.DETECTED.isDirectory(file)) {
	return;
	}
	for (File child : file.listFiles()) {
	FileUtils.delete(child, FileUtils.RECURSIVE \| FileUtils.SKIP_MISSING
	\| FileUtils.IGNORE_ERRORS);
	}
	}
	}