org.eclipse.jgit/src/org/eclipse/jgit/transport/WalkPushConnection.java - sop/jgit - Git at Google

 /*
  * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
  * 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.transport;

 import static org.eclipse.jgit.transport.WalkRemoteObjectDatabase.ROOT_DIR;

 import java.io.BufferedOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeMap;

 import org.eclipse.jgit.errors.TransportException;
 import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.internal.storage.pack.PackWriter;
 import org.eclipse.jgit.lib.AnyObjectId;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectIdRef;
 import org.eclipse.jgit.lib.ProgressMonitor;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Ref.Storage;
 import org.eclipse.jgit.lib.RefWriter;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.transport.RemoteRefUpdate.Status;

 /**
  * Generic push support for dumb transport protocols.
  * <p>
  * Since there are no Git-specific smarts on the remote side of the connection
  * the client side must handle everything on its own. The generic push support
  * requires being able to delete, create and overwrite files on the remote side,
  * as well as create any missing directories (if necessary). Typically this can
  * be handled through an FTP style protocol.
  * <p>
  * Objects not on the remote side are uploaded as pack files, using one pack
  * file per invocation. This simplifies the implementation as only two data
  * files need to be written to the remote repository.
  * <p>
  * Push support supplied by this class is not multiuser safe. Concurrent pushes
  * to the same repository may yield an inconsistent reference database which may
  * confuse fetch clients.
  * <p>
  * A single push is concurrently safe with multiple fetch requests, due to the
  * careful order of operations used to update the repository. Clients fetching
  * may receive transient failures due to short reads on certain files if the
  * protocol does not support atomic file replacement.
  *
  * @see WalkRemoteObjectDatabase
  */
 class WalkPushConnection extends BaseConnection implements PushConnection {
 	/** The repository this transport pushes out of. */
 	private final Repository local;

 	/** Location of the remote repository we are writing to. */
 	private final URIish uri;

 	/** Database connection to the remote repository. */
 	final WalkRemoteObjectDatabase dest;

 	/** The configured transport we were constructed by. */
 	private final Transport transport;

 	/**
 	 * Packs already known to reside in the remote repository.
 	 * <p>
 	 * This is a LinkedHashMap to maintain the original order.
 	 */
 	private LinkedHashMap<String, String> packNames;

 	/** Complete listing of refs the remote will have after our push. */
 	private Map<String, Ref> newRefs;

 	/**
 	 * Updates which require altering the packed-refs file to complete.
 	 * <p>
 	 * If this collection is non-empty then any refs listed in {@link #newRefs}
 	 * with a storage class of {@link Storage#PACKED} will be written.
 	 */
 	private Collection<RemoteRefUpdate> packedRefUpdates;

 	WalkPushConnection(final WalkTransport walkTransport,
 			final WalkRemoteObjectDatabase w) {
 		transport = (Transport) walkTransport;
 		local = transport.local;
 		uri = transport.getURI();
 		dest = w;
 	}

 	@Override
 	public void push(final ProgressMonitor monitor,
 			final Map<String, RemoteRefUpdate> refUpdates)
 			throws TransportException {
 		push(monitor, refUpdates, null);
 	}

 	@Override
 	public void push(final ProgressMonitor monitor,
 			final Map<String, RemoteRefUpdate> refUpdates, OutputStream out)
 			throws TransportException {
 		markStartedOperation();
 		packNames = null;
 		newRefs = new TreeMap<>(getRefsMap());
 		packedRefUpdates = new ArrayList<>(refUpdates.size());

 		// Filter the commands and issue all deletes first. This way we
 		// can correctly handle a directory being cleared out and a new
 		// ref using the directory name being created.
 		//
 		final List<RemoteRefUpdate> updates = new ArrayList<>();
 		for (final RemoteRefUpdate u : refUpdates.values()) {
 			final String n = u.getRemoteName();
 			if (!n.startsWith("refs/") || !Repository.isValidRefName(n)) { //$NON-NLS-1$
 				u.setStatus(Status.REJECTED_OTHER_REASON);
 				u.setMessage(JGitText.get().funnyRefname);
 				continue;
 			}

 			if (AnyObjectId.equals(ObjectId.zeroId(), u.getNewObjectId()))
 				deleteCommand(u);
 			else
 				updates.add(u);
 		}

 		// If we have any updates we need to upload the objects first, to
 		// prevent creating refs pointing at non-existent data. Then we
 		// can update the refs, and the info-refs file for dumb transports.
 		//
 		if (!updates.isEmpty())
 			sendpack(updates, monitor);
 		for (final RemoteRefUpdate u : updates)
 			updateCommand(u);

 		// Is this a new repository? If so we should create additional
 		// metadata files so it is properly initialized during the push.
 		//
 		if (!updates.isEmpty() && isNewRepository())
 			createNewRepository(updates);

 		RefWriter refWriter = new RefWriter(newRefs.values()) {
 			@Override
 			protected void writeFile(String file, byte[] content)
 					throws IOException {
 				dest.writeFile(ROOT_DIR + file, content);
 			}
 		};
 		if (!packedRefUpdates.isEmpty()) {
 			try {
 				refWriter.writePackedRefs();
 				for (final RemoteRefUpdate u : packedRefUpdates)
 					u.setStatus(Status.OK);
 			} catch (IOException err) {
 				for (final RemoteRefUpdate u : packedRefUpdates) {
 					u.setStatus(Status.REJECTED_OTHER_REASON);
 					u.setMessage(err.getMessage());
 				}
 				throw new TransportException(uri, JGitText.get().failedUpdatingRefs, err);
 			}
 		}

 		try {
 			refWriter.writeInfoRefs();
 		} catch (IOException err) {
 			throw new TransportException(uri, JGitText.get().failedUpdatingRefs, err);
 		}
 	}

 	@Override
 	public void close() {
 		dest.close();
 	}

 	private void sendpack(final List<RemoteRefUpdate> updates,
 			final ProgressMonitor monitor) throws TransportException {
 		String pathPack = null;
 		String pathIdx = null;

 		try (final PackWriter writer = new PackWriter(transport.getPackConfig(),
 				local.newObjectReader())) {

 			final Set<ObjectId> need = new HashSet<>();
 			final Set<ObjectId> have = new HashSet<>();
 			for (final RemoteRefUpdate r : updates)
 				need.add(r.getNewObjectId());
 			for (final Ref r : getRefs()) {
 				have.add(r.getObjectId());
 				if (r.getPeeledObjectId() != null)
 					have.add(r.getPeeledObjectId());
 			}
 			writer.preparePack(monitor, need, have);

 			// We don't have to continue further if the pack will
 			// be an empty pack, as the remote has all objects it
 			// needs to complete this change.
 			//
 			if (writer.getObjectCount() == 0)
 				return;

 			packNames = new LinkedHashMap<>();
 			for (final String n : dest.getPackNames())
 				packNames.put(n, n);

 			final String base = "pack-" + writer.computeName().name(); //$NON-NLS-1$
 			final String packName = base + ".pack"; //$NON-NLS-1$
 			pathPack = "pack/" + packName; //$NON-NLS-1$
 			pathIdx = "pack/" + base + ".idx"; //$NON-NLS-1$ //$NON-NLS-2$

 			if (packNames.remove(packName) != null) {
 				// The remote already contains this pack. We should
 				// remove the index before overwriting to prevent bad
 				// offsets from appearing to clients.
 				//
 				dest.writeInfoPacks(packNames.keySet());
 				dest.deleteFile(pathIdx);
 			}

 			// Write the pack file, then the index, as readers look the
 			// other direction (index, then pack file).
 			//
 			String wt = "Put " + base.substring(0, 12); //$NON-NLS-1$
 			try (OutputStream os = new BufferedOutputStream(
 					dest.writeFile(pathPack, monitor, wt + "..pack"))) { //$NON-NLS-1$
 				writer.writePack(monitor, monitor, os);
 			}

 			try (OutputStream os = new BufferedOutputStream(
 					dest.writeFile(pathIdx, monitor, wt + "..idx"))) { //$NON-NLS-1$
 				writer.writeIndex(os);
 			}

 			// Record the pack at the start of the pack info list. This
 			// way clients are likely to consult the newest pack first,
 			// and discover the most recent objects there.
 			//
 			final ArrayList<String> infoPacks = new ArrayList<>();
 			infoPacks.add(packName);
 			infoPacks.addAll(packNames.keySet());
 			dest.writeInfoPacks(infoPacks);

 		} catch (IOException err) {
 			safeDelete(pathIdx);
 			safeDelete(pathPack);

 			throw new TransportException(uri, JGitText.get().cannotStoreObjects, err);
 		}
 	}

 	private void safeDelete(final String path) {
 		if (path != null) {
 			try {
 				dest.deleteFile(path);
 			} catch (IOException cleanupFailure) {
 				// Ignore the deletion failure. We probably are
 				// already failing and were just trying to pick
 				// up after ourselves.
 			}
 		}
 	}

 	private void deleteCommand(final RemoteRefUpdate u) {
 		final Ref r = newRefs.remove(u.getRemoteName());
 		if (r == null) {
 			// Already gone.
 			//
 			u.setStatus(Status.OK);
 			return;
 		}

 		if (r.getStorage().isPacked())
 			packedRefUpdates.add(u);

 		if (r.getStorage().isLoose()) {
 			try {
 				dest.deleteRef(u.getRemoteName());
 				u.setStatus(Status.OK);
 			} catch (IOException e) {
 				u.setStatus(Status.REJECTED_OTHER_REASON);
 				u.setMessage(e.getMessage());
 			}
 		}

 		try {
 			dest.deleteRefLog(u.getRemoteName());
 		} catch (IOException e) {
 			u.setStatus(Status.REJECTED_OTHER_REASON);
 			u.setMessage(e.getMessage());
 		}
 	}

 	private void updateCommand(final RemoteRefUpdate u) {
 		try {
 			dest.writeRef(u.getRemoteName(), u.getNewObjectId());
 			newRefs.put(u.getRemoteName(), new ObjectIdRef.Unpeeled(
 					Storage.LOOSE, u.getRemoteName(), u.getNewObjectId()));
 			u.setStatus(Status.OK);
 		} catch (IOException e) {
 			u.setStatus(Status.REJECTED_OTHER_REASON);
 			u.setMessage(e.getMessage());
 		}
 	}

 	private boolean isNewRepository() {
 		return getRefsMap().isEmpty() && packNames != null
 				&& packNames.isEmpty();
 	}

 	private void createNewRepository(final List<RemoteRefUpdate> updates)
 			throws TransportException {
 		try {
 			final String ref = "ref: " + pickHEAD(updates) + "\n"; //$NON-NLS-1$ //$NON-NLS-2$
 			final byte[] bytes = Constants.encode(ref);
 			dest.writeFile(ROOT_DIR + Constants.HEAD, bytes);
 		} catch (IOException e) {
 			throw new TransportException(uri, JGitText.get().cannotCreateHEAD, e);
 		}

 		try {
 			final String config = "[core]\n" //$NON-NLS-1$
 					+ "\trepositoryformatversion = 0\n"; //$NON-NLS-1$
 			final byte[] bytes = Constants.encode(config);
 			dest.writeFile(ROOT_DIR + Constants.CONFIG, bytes);
 		} catch (IOException e) {
 			throw new TransportException(uri, JGitText.get().cannotCreateConfig, e);
 		}
 	}

 	private static String pickHEAD(final List<RemoteRefUpdate> updates) {
 		// Try to use master if the user is pushing that, it is the
 		// default branch and is likely what they want to remain as
 		// the default on the new remote.
 		//
 		for (final RemoteRefUpdate u : updates) {
 			final String n = u.getRemoteName();
 			if (n.equals(Constants.R_HEADS + Constants.MASTER))
 				return n;
 		}

 		// Pick any branch, under the assumption the user pushed only
 		// one to the remote side.
 		//
 		for (final RemoteRefUpdate u : updates) {
 			final String n = u.getRemoteName();
 			if (n.startsWith(Constants.R_HEADS))
 				return n;
 		}
 		return updates.get(0).getRemoteName();
 	}
 }
	/*
	* Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
	* 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.transport;

	import static org.eclipse.jgit.transport.WalkRemoteObjectDatabase.ROOT_DIR;

	import java.io.BufferedOutputStream;
	import java.io.IOException;
	import java.io.OutputStream;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.HashSet;
	import java.util.LinkedHashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;
	import java.util.TreeMap;

	import org.eclipse.jgit.errors.TransportException;
	import org.eclipse.jgit.internal.JGitText;
	import org.eclipse.jgit.internal.storage.pack.PackWriter;
	import org.eclipse.jgit.lib.AnyObjectId;
	import org.eclipse.jgit.lib.Constants;
	import org.eclipse.jgit.lib.ObjectId;
	import org.eclipse.jgit.lib.ObjectIdRef;
	import org.eclipse.jgit.lib.ProgressMonitor;
	import org.eclipse.jgit.lib.Ref;
	import org.eclipse.jgit.lib.Ref.Storage;
	import org.eclipse.jgit.lib.RefWriter;
	import org.eclipse.jgit.lib.Repository;
	import org.eclipse.jgit.transport.RemoteRefUpdate.Status;

	/**
	* Generic push support for dumb transport protocols.
	* <p>
	* Since there are no Git-specific smarts on the remote side of the connection
	* the client side must handle everything on its own. The generic push support
	* requires being able to delete, create and overwrite files on the remote side,
	* as well as create any missing directories (if necessary). Typically this can
	* be handled through an FTP style protocol.
	* <p>
	* Objects not on the remote side are uploaded as pack files, using one pack
	* file per invocation. This simplifies the implementation as only two data
	* files need to be written to the remote repository.
	* <p>
	* Push support supplied by this class is not multiuser safe. Concurrent pushes
	* to the same repository may yield an inconsistent reference database which may
	* confuse fetch clients.
	* <p>
	* A single push is concurrently safe with multiple fetch requests, due to the
	* careful order of operations used to update the repository. Clients fetching
	* may receive transient failures due to short reads on certain files if the
	* protocol does not support atomic file replacement.
	*
	* @see WalkRemoteObjectDatabase
	*/
	class WalkPushConnection extends BaseConnection implements PushConnection {
	/** The repository this transport pushes out of. */
	private final Repository local;

	/** Location of the remote repository we are writing to. */
	private final URIish uri;

	/** Database connection to the remote repository. */
	final WalkRemoteObjectDatabase dest;

	/** The configured transport we were constructed by. */
	private final Transport transport;

	/**
	* Packs already known to reside in the remote repository.
	* <p>
	* This is a LinkedHashMap to maintain the original order.
	*/
	private LinkedHashMap<String, String> packNames;

	/** Complete listing of refs the remote will have after our push. */
	private Map<String, Ref> newRefs;

	/**
	* Updates which require altering the packed-refs file to complete.
	* <p>
	* If this collection is non-empty then any refs listed in {@link #newRefs}
	* with a storage class of {@link Storage#PACKED} will be written.
	*/
	private Collection<RemoteRefUpdate> packedRefUpdates;

	WalkPushConnection(final WalkTransport walkTransport,
	final WalkRemoteObjectDatabase w) {
	transport = (Transport) walkTransport;
	local = transport.local;
	uri = transport.getURI();
	dest = w;
	}

	@Override
	public void push(final ProgressMonitor monitor,
	final Map<String, RemoteRefUpdate> refUpdates)
	throws TransportException {
	push(monitor, refUpdates, null);
	}

	@Override
	public void push(final ProgressMonitor monitor,
	final Map<String, RemoteRefUpdate> refUpdates, OutputStream out)
	throws TransportException {
	markStartedOperation();
	packNames = null;
	newRefs = new TreeMap<>(getRefsMap());
	packedRefUpdates = new ArrayList<>(refUpdates.size());

	// Filter the commands and issue all deletes first. This way we
	// can correctly handle a directory being cleared out and a new
	// ref using the directory name being created.
	//
	final List<RemoteRefUpdate> updates = new ArrayList<>();
	for (final RemoteRefUpdate u : refUpdates.values()) {
	final String n = u.getRemoteName();
	if (!n.startsWith("refs/") \|\| !Repository.isValidRefName(n)) { //$NON-NLS-1$
	u.setStatus(Status.REJECTED_OTHER_REASON);
	u.setMessage(JGitText.get().funnyRefname);
	continue;
	}

	if (AnyObjectId.equals(ObjectId.zeroId(), u.getNewObjectId()))
	deleteCommand(u);
	else
	updates.add(u);
	}

	// If we have any updates we need to upload the objects first, to
	// prevent creating refs pointing at non-existent data. Then we
	// can update the refs, and the info-refs file for dumb transports.
	//
	if (!updates.isEmpty())
	sendpack(updates, monitor);
	for (final RemoteRefUpdate u : updates)
	updateCommand(u);

	// Is this a new repository? If so we should create additional
	// metadata files so it is properly initialized during the push.
	//
	if (!updates.isEmpty() && isNewRepository())
	createNewRepository(updates);

	RefWriter refWriter = new RefWriter(newRefs.values()) {
	@Override
	protected void writeFile(String file, byte[] content)
	throws IOException {
	dest.writeFile(ROOT_DIR + file, content);
	}
	};
	if (!packedRefUpdates.isEmpty()) {
	try {
	refWriter.writePackedRefs();
	for (final RemoteRefUpdate u : packedRefUpdates)
	u.setStatus(Status.OK);
	} catch (IOException err) {
	for (final RemoteRefUpdate u : packedRefUpdates) {
	u.setStatus(Status.REJECTED_OTHER_REASON);
	u.setMessage(err.getMessage());
	}
	throw new TransportException(uri, JGitText.get().failedUpdatingRefs, err);
	}
	}

	try {
	refWriter.writeInfoRefs();
	} catch (IOException err) {
	throw new TransportException(uri, JGitText.get().failedUpdatingRefs, err);
	}
	}

	@Override
	public void close() {
	dest.close();
	}

	private void sendpack(final List<RemoteRefUpdate> updates,
	final ProgressMonitor monitor) throws TransportException {
	String pathPack = null;
	String pathIdx = null;

	try (final PackWriter writer = new PackWriter(transport.getPackConfig(),
	local.newObjectReader())) {

	final Set<ObjectId> need = new HashSet<>();
	final Set<ObjectId> have = new HashSet<>();
	for (final RemoteRefUpdate r : updates)
	need.add(r.getNewObjectId());
	for (final Ref r : getRefs()) {
	have.add(r.getObjectId());
	if (r.getPeeledObjectId() != null)
	have.add(r.getPeeledObjectId());
	}
	writer.preparePack(monitor, need, have);

	// We don't have to continue further if the pack will
	// be an empty pack, as the remote has all objects it
	// needs to complete this change.
	//
	if (writer.getObjectCount() == 0)
	return;

	packNames = new LinkedHashMap<>();
	for (final String n : dest.getPackNames())
	packNames.put(n, n);

	final String base = "pack-" + writer.computeName().name(); //$NON-NLS-1$
	final String packName = base + ".pack"; //$NON-NLS-1$
	pathPack = "pack/" + packName; //$NON-NLS-1$
	pathIdx = "pack/" + base + ".idx"; //$NON-NLS-1$ //$NON-NLS-2$

	if (packNames.remove(packName) != null) {
	// The remote already contains this pack. We should
	// remove the index before overwriting to prevent bad
	// offsets from appearing to clients.
	//
	dest.writeInfoPacks(packNames.keySet());
	dest.deleteFile(pathIdx);
	}

	// Write the pack file, then the index, as readers look the
	// other direction (index, then pack file).
	//
	String wt = "Put " + base.substring(0, 12); //$NON-NLS-1$
	try (OutputStream os = new BufferedOutputStream(
	dest.writeFile(pathPack, monitor, wt + "..pack"))) { //$NON-NLS-1$
	writer.writePack(monitor, monitor, os);
	}

	try (OutputStream os = new BufferedOutputStream(
	dest.writeFile(pathIdx, monitor, wt + "..idx"))) { //$NON-NLS-1$
	writer.writeIndex(os);
	}

	// Record the pack at the start of the pack info list. This
	// way clients are likely to consult the newest pack first,
	// and discover the most recent objects there.
	//
	final ArrayList<String> infoPacks = new ArrayList<>();
	infoPacks.add(packName);
	infoPacks.addAll(packNames.keySet());
	dest.writeInfoPacks(infoPacks);

	} catch (IOException err) {
	safeDelete(pathIdx);
	safeDelete(pathPack);

	throw new TransportException(uri, JGitText.get().cannotStoreObjects, err);
	}
	}

	private void safeDelete(final String path) {
	if (path != null) {
	try {
	dest.deleteFile(path);
	} catch (IOException cleanupFailure) {
	// Ignore the deletion failure. We probably are
	// already failing and were just trying to pick
	// up after ourselves.
	}
	}
	}

	private void deleteCommand(final RemoteRefUpdate u) {
	final Ref r = newRefs.remove(u.getRemoteName());
	if (r == null) {
	// Already gone.
	//
	u.setStatus(Status.OK);
	return;
	}

	if (r.getStorage().isPacked())
	packedRefUpdates.add(u);

	if (r.getStorage().isLoose()) {
	try {
	dest.deleteRef(u.getRemoteName());
	u.setStatus(Status.OK);
	} catch (IOException e) {
	u.setStatus(Status.REJECTED_OTHER_REASON);
	u.setMessage(e.getMessage());
	}
	}

	try {
	dest.deleteRefLog(u.getRemoteName());
	} catch (IOException e) {
	u.setStatus(Status.REJECTED_OTHER_REASON);
	u.setMessage(e.getMessage());
	}
	}

	private void updateCommand(final RemoteRefUpdate u) {
	try {
	dest.writeRef(u.getRemoteName(), u.getNewObjectId());
	newRefs.put(u.getRemoteName(), new ObjectIdRef.Unpeeled(
	Storage.LOOSE, u.getRemoteName(), u.getNewObjectId()));
	u.setStatus(Status.OK);
	} catch (IOException e) {
	u.setStatus(Status.REJECTED_OTHER_REASON);
	u.setMessage(e.getMessage());
	}
	}

	private boolean isNewRepository() {
	return getRefsMap().isEmpty() && packNames != null
	&& packNames.isEmpty();
	}

	private void createNewRepository(final List<RemoteRefUpdate> updates)
	throws TransportException {
	try {
	final String ref = "ref: " + pickHEAD(updates) + "\n"; //$NON-NLS-1$ //$NON-NLS-2$
	final byte[] bytes = Constants.encode(ref);
	dest.writeFile(ROOT_DIR + Constants.HEAD, bytes);
	} catch (IOException e) {
	throw new TransportException(uri, JGitText.get().cannotCreateHEAD, e);
	}

	try {
	final String config = "[core]\n" //$NON-NLS-1$
	+ "\trepositoryformatversion = 0\n"; //$NON-NLS-1$
	final byte[] bytes = Constants.encode(config);
	dest.writeFile(ROOT_DIR + Constants.CONFIG, bytes);
	} catch (IOException e) {
	throw new TransportException(uri, JGitText.get().cannotCreateConfig, e);
	}
	}

	private static String pickHEAD(final List<RemoteRefUpdate> updates) {
	// Try to use master if the user is pushing that, it is the
	// default branch and is likely what they want to remain as
	// the default on the new remote.
	//
	for (final RemoteRefUpdate u : updates) {
	final String n = u.getRemoteName();
	if (n.equals(Constants.R_HEADS + Constants.MASTER))
	return n;
	}

	// Pick any branch, under the assumption the user pushed only
	// one to the remote side.
	//
	for (final RemoteRefUpdate u : updates) {
	final String n = u.getRemoteName();
	if (n.startsWith(Constants.R_HEADS))
	return n;
	}
	return updates.get(0).getRemoteName();
	}
	}