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

 /*
  * Copyright (C) 2008, Marek Zawirski <marek.zawirski@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.transport;

 import java.io.IOException;
 import java.text.MessageFormat;

 import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.RefUpdate;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevWalk;

 /**
  * Represent request and status of a remote ref update. Specification is
  * provided by client, while status is handled by {@link PushProcess} class,
  * being read-only for client.
  * <p>
  * Client can create instances of this class directly, basing on user
  * specification and advertised refs ({@link Connection} or through
  * {@link Transport} helper methods. Apply this specification on remote
  * repository using
  * {@link Transport#push(org.eclipse.jgit.lib.ProgressMonitor, java.util.Collection)}
  * method.
  * </p>
  *
  */
 public class RemoteRefUpdate {
 	/**
 	 * Represent current status of a remote ref update.
 	 */
 	public static enum Status {
 		/**
 		 * Push process hasn't yet attempted to update this ref. This is the
 		 * default status, prior to push process execution.
 		 */
 		NOT_ATTEMPTED,

 		/**
 		 * Remote ref was up to date, there was no need to update anything.
 		 */
 		UP_TO_DATE,

 		/**
 		 * Remote ref update was rejected, as it would cause non fast-forward
 		 * update.
 		 */
 		REJECTED_NONFASTFORWARD,

 		/**
 		 * Remote ref update was rejected, because remote side doesn't
 		 * support/allow deleting refs.
 		 */
 		REJECTED_NODELETE,

 		/**
 		 * Remote ref update was rejected, because old object id on remote
 		 * repository wasn't the same as defined expected old object.
 		 */
 		REJECTED_REMOTE_CHANGED,

 		/**
 		 * Remote ref update was rejected for other reason, possibly described
 		 * in {@link RemoteRefUpdate#getMessage()}.
 		 */
 		REJECTED_OTHER_REASON,

 		/**
 		 * Remote ref didn't exist. Can occur on delete request of a non
 		 * existing ref.
 		 */
 		NON_EXISTING,

 		/**
 		 * Push process is awaiting update report from remote repository. This
 		 * is a temporary state or state after critical error in push process.
 		 */
 		AWAITING_REPORT,

 		/**
 		 * Remote ref was successfully updated.
 		 */
 		OK;
 	}

 	private ObjectId expectedOldObjectId;

 	private final ObjectId newObjectId;

 	private final String remoteName;

 	private final TrackingRefUpdate trackingRefUpdate;

 	private final String srcRef;

 	private final boolean forceUpdate;

 	private Status status;

 	private boolean fastForward;

 	private String message;

 	private final Repository localDb;

 	private RefUpdate localUpdate;

 	/**
 	 * Construct remote ref update request by providing an update specification.
 	 * Object is created with default {@link Status#NOT_ATTEMPTED} status and no
 	 * message.
 	 *
 	 * @param localDb
 	 *            local repository to push from.
 	 * @param srcRef
 	 *            source revision - any string resolvable by
 	 *            {@link Repository#resolve(String)}. This resolves to the new
 	 *            object that the caller want remote ref to be after update. Use
 	 *            null or {@link ObjectId#zeroId()} string for delete request.
 	 * @param remoteName
 	 *            full name of a remote ref to update, e.g. "refs/heads/master"
 	 *            (no wildcard, no short name).
 	 * @param forceUpdate
 	 *            true when caller want remote ref to be updated regardless
 	 *            whether it is fast-forward update (old object is ancestor of
 	 *            new object).
 	 * @param localName
 	 *            optional full name of a local stored tracking branch, to
 	 *            update after push, e.g. "refs/remotes/zawir/dirty" (no
 	 *            wildcard, no short name); null if no local tracking branch
 	 *            should be updated.
 	 * @param expectedOldObjectId
 	 *            optional object id that caller is expecting, requiring to be
 	 *            advertised by remote side before update; update will take
 	 *            place ONLY if remote side advertise exactly this expected id;
 	 *            null if caller doesn't care what object id remote side
 	 *            advertise. Use {@link ObjectId#zeroId()} when expecting no
 	 *            remote ref with this name.
 	 * @throws IOException
 	 *             when I/O error occurred during creating
 	 *             {@link TrackingRefUpdate} for local tracking branch or srcRef
 	 *             can't be resolved to any object.
 	 * @throws IllegalArgumentException
 	 *             if some required parameter was null
 	 */
 	public RemoteRefUpdate(final Repository localDb, final String srcRef,
 			final String remoteName, final boolean forceUpdate,
 			final String localName, final ObjectId expectedOldObjectId)
 			throws IOException {
 		this(localDb, srcRef, srcRef != null ? localDb.resolve(srcRef)
 				: ObjectId.zeroId(), remoteName, forceUpdate, localName,
 				expectedOldObjectId);
 	}

 	/**
 	 * Construct remote ref update request by providing an update specification.
 	 * Object is created with default {@link Status#NOT_ATTEMPTED} status and no
 	 * message.
 	 *
 	 * @param localDb
 	 *            local repository to push from.
 	 * @param srcRef
 	 *            source revision. Use null to delete.
 	 * @param remoteName
 	 *            full name of a remote ref to update, e.g. "refs/heads/master"
 	 *            (no wildcard, no short name).
 	 * @param forceUpdate
 	 *            true when caller want remote ref to be updated regardless
 	 *            whether it is fast-forward update (old object is ancestor of
 	 *            new object).
 	 * @param localName
 	 *            optional full name of a local stored tracking branch, to
 	 *            update after push, e.g. "refs/remotes/zawir/dirty" (no
 	 *            wildcard, no short name); null if no local tracking branch
 	 *            should be updated.
 	 * @param expectedOldObjectId
 	 *            optional object id that caller is expecting, requiring to be
 	 *            advertised by remote side before update; update will take
 	 *            place ONLY if remote side advertise exactly this expected id;
 	 *            null if caller doesn't care what object id remote side
 	 *            advertise. Use {@link ObjectId#zeroId()} when expecting no
 	 *            remote ref with this name.
 	 * @throws IOException
 	 *             when I/O error occurred during creating
 	 *             {@link TrackingRefUpdate} for local tracking branch or srcRef
 	 *             can't be resolved to any object.
 	 * @throws IllegalArgumentException
 	 *             if some required parameter was null
 	 */
 	public RemoteRefUpdate(final Repository localDb, final Ref srcRef,
 			final String remoteName, final boolean forceUpdate,
 			final String localName, final ObjectId expectedOldObjectId)
 			throws IOException {
 		this(localDb, srcRef != null ? srcRef.getName() : null,
 				srcRef != null ? srcRef.getObjectId() : null, remoteName,
 				forceUpdate, localName, expectedOldObjectId);
 	}

 	/**
 	 * Construct remote ref update request by providing an update specification.
 	 * Object is created with default {@link Status#NOT_ATTEMPTED} status and no
 	 * message.
 	 *
 	 * @param localDb
 	 *            local repository to push from.
 	 * @param srcRef
 	 *            source revision to label srcId with. If null srcId.name() will
 	 *            be used instead.
 	 * @param srcId
 	 *            The new object that the caller wants remote ref to be after
 	 *            update. Use null or {@link ObjectId#zeroId()} for delete
 	 *            request.
 	 * @param remoteName
 	 *            full name of a remote ref to update, e.g. "refs/heads/master"
 	 *            (no wildcard, no short name).
 	 * @param forceUpdate
 	 *            true when caller want remote ref to be updated regardless
 	 *            whether it is fast-forward update (old object is ancestor of
 	 *            new object).
 	 * @param localName
 	 *            optional full name of a local stored tracking branch, to
 	 *            update after push, e.g. "refs/remotes/zawir/dirty" (no
 	 *            wildcard, no short name); null if no local tracking branch
 	 *            should be updated.
 	 * @param expectedOldObjectId
 	 *            optional object id that caller is expecting, requiring to be
 	 *            advertised by remote side before update; update will take
 	 *            place ONLY if remote side advertise exactly this expected id;
 	 *            null if caller doesn't care what object id remote side
 	 *            advertise. Use {@link ObjectId#zeroId()} when expecting no
 	 *            remote ref with this name.
 	 * @throws IOException
 	 *             when I/O error occurred during creating
 	 *             {@link TrackingRefUpdate} for local tracking branch or srcRef
 	 *             can't be resolved to any object.
 	 * @throws IllegalArgumentException
 	 *             if some required parameter was null
 	 */
 	public RemoteRefUpdate(final Repository localDb, final String srcRef,
 			final ObjectId srcId, final String remoteName,
 			final boolean forceUpdate, final String localName,
 			final ObjectId expectedOldObjectId) throws IOException {
 		if (remoteName == null)
 			throw new IllegalArgumentException(JGitText.get().remoteNameCantBeNull);
 		if (srcId == null && srcRef != null)
 			throw new IOException(MessageFormat.format(
 					JGitText.get().sourceRefDoesntResolveToAnyObject, srcRef));

 		if (srcRef != null)
 			this.srcRef = srcRef;
 		else if (srcId != null && !srcId.equals(ObjectId.zeroId()))
 			this.srcRef = srcId.name();
 		else
 			this.srcRef = null;

 		if (srcId != null)
 			this.newObjectId = srcId;
 		else
 			this.newObjectId = ObjectId.zeroId();

 		this.remoteName = remoteName;
 		this.forceUpdate = forceUpdate;
 		if (localName != null && localDb != null) {
 			localUpdate = localDb.updateRef(localName);
 			localUpdate.setForceUpdate(true);
 			localUpdate.setRefLogMessage("push", true); //$NON-NLS-1$
 			localUpdate.setNewObjectId(newObjectId);
 			trackingRefUpdate = new TrackingRefUpdate(
 					true,
 					remoteName,
 					localName,
 					localUpdate.getOldObjectId() != null
 						? localUpdate.getOldObjectId()
 						: ObjectId.zeroId(),
 					newObjectId);
 		} else
 			trackingRefUpdate = null;
 		this.localDb = localDb;
 		this.expectedOldObjectId = expectedOldObjectId;
 		this.status = Status.NOT_ATTEMPTED;
 	}

 	/**
 	 * Create a new instance of this object basing on existing instance for
 	 * configuration. State (like {@link #getMessage()}, {@link #getStatus()})
 	 * of base object is not shared. Expected old object id is set up from
 	 * scratch, as this constructor may be used for 2-stage push: first one
 	 * being dry run, second one being actual push.
 	 *
 	 * @param base
 	 *            configuration base.
 	 * @param newExpectedOldObjectId
 	 *            new expected object id value.
 	 * @throws IOException
 	 *             when I/O error occurred during creating
 	 *             {@link TrackingRefUpdate} for local tracking branch or srcRef
 	 *             of base object no longer can be resolved to any object.
 	 */
 	public RemoteRefUpdate(final RemoteRefUpdate base,
 			final ObjectId newExpectedOldObjectId) throws IOException {
 		this(base.localDb, base.srcRef, base.remoteName, base.forceUpdate,
 				(base.trackingRefUpdate == null ? null : base.trackingRefUpdate
 						.getLocalName()), newExpectedOldObjectId);
 	}

 	/**
 	 * @return expectedOldObjectId required to be advertised by remote side, as
 	 *         set in constructor; may be null.
 	 */
 	public ObjectId getExpectedOldObjectId() {
 		return expectedOldObjectId;
 	}

 	/**
 	 * @return true if some object is required to be advertised by remote side,
 	 *         as set in constructor; false otherwise.
 	 */
 	public boolean isExpectingOldObjectId() {
 		return expectedOldObjectId != null;
 	}

 	/**
 	 * @return newObjectId for remote ref, as set in constructor.
 	 */
 	public ObjectId getNewObjectId() {
 		return newObjectId;
 	}

 	/**
 	 * @return true if this update is deleting update; false otherwise.
 	 */
 	public boolean isDelete() {
 		return ObjectId.zeroId().equals(newObjectId);
 	}

 	/**
 	 * @return name of remote ref to update, as set in constructor.
 	 */
 	public String getRemoteName() {
 		return remoteName;
 	}

 	/**
 	 * @return local tracking branch update if localName was set in constructor.
 	 */
 	public TrackingRefUpdate getTrackingRefUpdate() {
 		return trackingRefUpdate;
 	}

 	/**
 	 * @return source revision as specified by user (in constructor), could be
 	 *         any string parseable by {@link Repository#resolve(String)}; can
 	 *         be null if specified that way in constructor - this stands for
 	 *         delete request.
 	 */
 	public String getSrcRef() {
 		return srcRef;
 	}

 	/**
 	 * @return true if user specified a local tracking branch for remote update;
 	 *         false otherwise.
 	 */
 	public boolean hasTrackingRefUpdate() {
 		return trackingRefUpdate != null;
 	}

 	/**
 	 * @return true if this update is forced regardless of old remote ref
 	 *         object; false otherwise.
 	 */
 	public boolean isForceUpdate() {
 		return forceUpdate;
 	}

 	/**
 	 * @return status of remote ref update operation.
 	 */
 	public Status getStatus() {
 		return status;
 	}

 	/**
 	 * Check whether update was fast-forward. Note that this result is
 	 * meaningful only after successful update (when status is {@link Status#OK}).
 	 *
 	 * @return true if update was fast-forward; false otherwise.
 	 */
 	public boolean isFastForward() {
 		return fastForward;
 	}

 	/**
 	 * @return message describing reasons of status when needed/possible; may be
 	 *         null.
 	 */
 	public String getMessage() {
 		return message;
 	}

 	void setExpectedOldObjectId(ObjectId id) {
 		expectedOldObjectId = id;
 	}

 	void setStatus(final Status status) {
 		this.status = status;
 	}

 	void setFastForward(boolean fastForward) {
 		this.fastForward = fastForward;
 	}

 	void setMessage(final String message) {
 		this.message = message;
 	}

 	/**
 	 * Update locally stored tracking branch with the new object.
 	 *
 	 * @param walk
 	 *            walker used for checking update properties.
 	 * @throws IOException
 	 *             when I/O error occurred during update
 	 */
 	protected void updateTrackingRef(final RevWalk walk) throws IOException {
 		if (isDelete())
 			trackingRefUpdate.setResult(localUpdate.delete(walk));
 		else
 			trackingRefUpdate.setResult(localUpdate.update(walk));
 	}

 	@SuppressWarnings("nls")
 	@Override
 	public String toString() {
 		return "RemoteRefUpdate[remoteName="
 				+ remoteName
 				+ ", "
 				+ status
 				+ ", "
 				+ (expectedOldObjectId != null ? expectedOldObjectId.name()
 						: "(null)") + "..."
 				+ (newObjectId != null ? newObjectId.name() : "(null)")
 				+ (fastForward ? ", fastForward" : "")
  + ", srcRef=" + srcRef
 				+ (forceUpdate ? ", forceUpdate" : "") + ", message="
 				+ (message != null ? "\"" + message + "\"" : "null") + "]";
 	}
 }
	/*
	* Copyright (C) 2008, Marek Zawirski <marek.zawirski@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.transport;

	import java.io.IOException;
	import java.text.MessageFormat;

	import org.eclipse.jgit.internal.JGitText;
	import org.eclipse.jgit.lib.ObjectId;
	import org.eclipse.jgit.lib.Ref;
	import org.eclipse.jgit.lib.RefUpdate;
	import org.eclipse.jgit.lib.Repository;
	import org.eclipse.jgit.revwalk.RevWalk;

	/**
	* Represent request and status of a remote ref update. Specification is
	* provided by client, while status is handled by {@link PushProcess} class,
	* being read-only for client.
	* <p>
	* Client can create instances of this class directly, basing on user
	* specification and advertised refs ({@link Connection} or through
	* {@link Transport} helper methods. Apply this specification on remote
	* repository using
	* {@link Transport#push(org.eclipse.jgit.lib.ProgressMonitor, java.util.Collection)}
	* method.
	* </p>
	*
	*/
	public class RemoteRefUpdate {
	/**
	* Represent current status of a remote ref update.
	*/
	public static enum Status {
	/**
	* Push process hasn't yet attempted to update this ref. This is the
	* default status, prior to push process execution.
	*/
	NOT_ATTEMPTED,

	/**
	* Remote ref was up to date, there was no need to update anything.
	*/
	UP_TO_DATE,

	/**
	* Remote ref update was rejected, as it would cause non fast-forward
	* update.
	*/
	REJECTED_NONFASTFORWARD,

	/**
	* Remote ref update was rejected, because remote side doesn't
	* support/allow deleting refs.
	*/
	REJECTED_NODELETE,

	/**
	* Remote ref update was rejected, because old object id on remote
	* repository wasn't the same as defined expected old object.
	*/
	REJECTED_REMOTE_CHANGED,

	/**
	* Remote ref update was rejected for other reason, possibly described
	* in {@link RemoteRefUpdate#getMessage()}.
	*/
	REJECTED_OTHER_REASON,

	/**
	* Remote ref didn't exist. Can occur on delete request of a non
	* existing ref.
	*/
	NON_EXISTING,

	/**
	* Push process is awaiting update report from remote repository. This
	* is a temporary state or state after critical error in push process.
	*/
	AWAITING_REPORT,

	/**
	* Remote ref was successfully updated.
	*/
	OK;
	}

	private ObjectId expectedOldObjectId;

	private final ObjectId newObjectId;

	private final String remoteName;

	private final TrackingRefUpdate trackingRefUpdate;

	private final String srcRef;

	private final boolean forceUpdate;

	private Status status;

	private boolean fastForward;

	private String message;

	private final Repository localDb;

	private RefUpdate localUpdate;

	/**
	* Construct remote ref update request by providing an update specification.
	* Object is created with default {@link Status#NOT_ATTEMPTED} status and no
	* message.
	*
	* @param localDb
	* local repository to push from.
	* @param srcRef
	* source revision - any string resolvable by
	* {@link Repository#resolve(String)}. This resolves to the new
	* object that the caller want remote ref to be after update. Use
	* null or {@link ObjectId#zeroId()} string for delete request.
	* @param remoteName
	* full name of a remote ref to update, e.g. "refs/heads/master"
	* (no wildcard, no short name).
	* @param forceUpdate
	* true when caller want remote ref to be updated regardless
	* whether it is fast-forward update (old object is ancestor of
	* new object).
	* @param localName
	* optional full name of a local stored tracking branch, to
	* update after push, e.g. "refs/remotes/zawir/dirty" (no
	* wildcard, no short name); null if no local tracking branch
	* should be updated.
	* @param expectedOldObjectId
	* optional object id that caller is expecting, requiring to be
	* advertised by remote side before update; update will take
	* place ONLY if remote side advertise exactly this expected id;
	* null if caller doesn't care what object id remote side
	* advertise. Use {@link ObjectId#zeroId()} when expecting no
	* remote ref with this name.
	* @throws IOException
	* when I/O error occurred during creating
	* {@link TrackingRefUpdate} for local tracking branch or srcRef
	* can't be resolved to any object.
	* @throws IllegalArgumentException
	* if some required parameter was null
	*/
	public RemoteRefUpdate(final Repository localDb, final String srcRef,
	final String remoteName, final boolean forceUpdate,
	final String localName, final ObjectId expectedOldObjectId)
	throws IOException {
	this(localDb, srcRef, srcRef != null ? localDb.resolve(srcRef)
	: ObjectId.zeroId(), remoteName, forceUpdate, localName,
	expectedOldObjectId);
	}

	/**
	* Construct remote ref update request by providing an update specification.
	* Object is created with default {@link Status#NOT_ATTEMPTED} status and no
	* message.
	*
	* @param localDb
	* local repository to push from.
	* @param srcRef
	* source revision. Use null to delete.
	* @param remoteName
	* full name of a remote ref to update, e.g. "refs/heads/master"
	* (no wildcard, no short name).
	* @param forceUpdate
	* true when caller want remote ref to be updated regardless
	* whether it is fast-forward update (old object is ancestor of
	* new object).
	* @param localName
	* optional full name of a local stored tracking branch, to
	* update after push, e.g. "refs/remotes/zawir/dirty" (no
	* wildcard, no short name); null if no local tracking branch
	* should be updated.
	* @param expectedOldObjectId
	* optional object id that caller is expecting, requiring to be
	* advertised by remote side before update; update will take
	* place ONLY if remote side advertise exactly this expected id;
	* null if caller doesn't care what object id remote side
	* advertise. Use {@link ObjectId#zeroId()} when expecting no
	* remote ref with this name.
	* @throws IOException
	* when I/O error occurred during creating
	* {@link TrackingRefUpdate} for local tracking branch or srcRef
	* can't be resolved to any object.
	* @throws IllegalArgumentException
	* if some required parameter was null
	*/
	public RemoteRefUpdate(final Repository localDb, final Ref srcRef,
	final String remoteName, final boolean forceUpdate,
	final String localName, final ObjectId expectedOldObjectId)
	throws IOException {
	this(localDb, srcRef != null ? srcRef.getName() : null,
	srcRef != null ? srcRef.getObjectId() : null, remoteName,
	forceUpdate, localName, expectedOldObjectId);
	}

	/**
	* Construct remote ref update request by providing an update specification.
	* Object is created with default {@link Status#NOT_ATTEMPTED} status and no
	* message.
	*
	* @param localDb
	* local repository to push from.
	* @param srcRef
	* source revision to label srcId with. If null srcId.name() will
	* be used instead.
	* @param srcId
	* The new object that the caller wants remote ref to be after
	* update. Use null or {@link ObjectId#zeroId()} for delete
	* request.
	* @param remoteName
	* full name of a remote ref to update, e.g. "refs/heads/master"
	* (no wildcard, no short name).
	* @param forceUpdate
	* true when caller want remote ref to be updated regardless
	* whether it is fast-forward update (old object is ancestor of
	* new object).
	* @param localName
	* optional full name of a local stored tracking branch, to
	* update after push, e.g. "refs/remotes/zawir/dirty" (no
	* wildcard, no short name); null if no local tracking branch
	* should be updated.
	* @param expectedOldObjectId
	* optional object id that caller is expecting, requiring to be
	* advertised by remote side before update; update will take
	* place ONLY if remote side advertise exactly this expected id;
	* null if caller doesn't care what object id remote side
	* advertise. Use {@link ObjectId#zeroId()} when expecting no
	* remote ref with this name.
	* @throws IOException
	* when I/O error occurred during creating
	* {@link TrackingRefUpdate} for local tracking branch or srcRef
	* can't be resolved to any object.
	* @throws IllegalArgumentException
	* if some required parameter was null
	*/
	public RemoteRefUpdate(final Repository localDb, final String srcRef,
	final ObjectId srcId, final String remoteName,
	final boolean forceUpdate, final String localName,
	final ObjectId expectedOldObjectId) throws IOException {
	if (remoteName == null)
	throw new IllegalArgumentException(JGitText.get().remoteNameCantBeNull);
	if (srcId == null && srcRef != null)
	throw new IOException(MessageFormat.format(
	JGitText.get().sourceRefDoesntResolveToAnyObject, srcRef));

	if (srcRef != null)
	this.srcRef = srcRef;
	else if (srcId != null && !srcId.equals(ObjectId.zeroId()))
	this.srcRef = srcId.name();
	else
	this.srcRef = null;

	if (srcId != null)
	this.newObjectId = srcId;
	else
	this.newObjectId = ObjectId.zeroId();

	this.remoteName = remoteName;
	this.forceUpdate = forceUpdate;
	if (localName != null && localDb != null) {
	localUpdate = localDb.updateRef(localName);
	localUpdate.setForceUpdate(true);
	localUpdate.setRefLogMessage("push", true); //$NON-NLS-1$
	localUpdate.setNewObjectId(newObjectId);
	trackingRefUpdate = new TrackingRefUpdate(
	true,
	remoteName,
	localName,
	localUpdate.getOldObjectId() != null
	? localUpdate.getOldObjectId()
	: ObjectId.zeroId(),
	newObjectId);
	} else
	trackingRefUpdate = null;
	this.localDb = localDb;
	this.expectedOldObjectId = expectedOldObjectId;
	this.status = Status.NOT_ATTEMPTED;
	}

	/**
	* Create a new instance of this object basing on existing instance for
	* configuration. State (like {@link #getMessage()}, {@link #getStatus()})
	* of base object is not shared. Expected old object id is set up from
	* scratch, as this constructor may be used for 2-stage push: first one
	* being dry run, second one being actual push.
	*
	* @param base
	* configuration base.
	* @param newExpectedOldObjectId
	* new expected object id value.
	* @throws IOException
	* when I/O error occurred during creating
	* {@link TrackingRefUpdate} for local tracking branch or srcRef
	* of base object no longer can be resolved to any object.
	*/
	public RemoteRefUpdate(final RemoteRefUpdate base,
	final ObjectId newExpectedOldObjectId) throws IOException {
	this(base.localDb, base.srcRef, base.remoteName, base.forceUpdate,
	(base.trackingRefUpdate == null ? null : base.trackingRefUpdate
	.getLocalName()), newExpectedOldObjectId);
	}

	/**
	* @return expectedOldObjectId required to be advertised by remote side, as
	* set in constructor; may be null.
	*/
	public ObjectId getExpectedOldObjectId() {
	return expectedOldObjectId;
	}

	/**
	* @return true if some object is required to be advertised by remote side,
	* as set in constructor; false otherwise.
	*/
	public boolean isExpectingOldObjectId() {
	return expectedOldObjectId != null;
	}

	/**
	* @return newObjectId for remote ref, as set in constructor.
	*/
	public ObjectId getNewObjectId() {
	return newObjectId;
	}

	/**
	* @return true if this update is deleting update; false otherwise.
	*/
	public boolean isDelete() {
	return ObjectId.zeroId().equals(newObjectId);
	}

	/**
	* @return name of remote ref to update, as set in constructor.
	*/
	public String getRemoteName() {
	return remoteName;
	}

	/**
	* @return local tracking branch update if localName was set in constructor.
	*/
	public TrackingRefUpdate getTrackingRefUpdate() {
	return trackingRefUpdate;
	}

	/**
	* @return source revision as specified by user (in constructor), could be
	* any string parseable by {@link Repository#resolve(String)}; can
	* be null if specified that way in constructor - this stands for
	* delete request.
	*/
	public String getSrcRef() {
	return srcRef;
	}

	/**
	* @return true if user specified a local tracking branch for remote update;
	* false otherwise.
	*/
	public boolean hasTrackingRefUpdate() {
	return trackingRefUpdate != null;
	}

	/**
	* @return true if this update is forced regardless of old remote ref
	* object; false otherwise.
	*/
	public boolean isForceUpdate() {
	return forceUpdate;
	}

	/**
	* @return status of remote ref update operation.
	*/
	public Status getStatus() {
	return status;
	}

	/**
	* Check whether update was fast-forward. Note that this result is
	* meaningful only after successful update (when status is {@link Status#OK}).
	*
	* @return true if update was fast-forward; false otherwise.
	*/
	public boolean isFastForward() {
	return fastForward;
	}

	/**
	* @return message describing reasons of status when needed/possible; may be
	* null.
	*/
	public String getMessage() {
	return message;
	}

	void setExpectedOldObjectId(ObjectId id) {
	expectedOldObjectId = id;
	}

	void setStatus(final Status status) {
	this.status = status;
	}

	void setFastForward(boolean fastForward) {
	this.fastForward = fastForward;
	}

	void setMessage(final String message) {
	this.message = message;
	}

	/**
	* Update locally stored tracking branch with the new object.
	*
	* @param walk
	* walker used for checking update properties.
	* @throws IOException
	* when I/O error occurred during update
	*/
	protected void updateTrackingRef(final RevWalk walk) throws IOException {
	if (isDelete())
	trackingRefUpdate.setResult(localUpdate.delete(walk));
	else
	trackingRefUpdate.setResult(localUpdate.update(walk));
	}

	@SuppressWarnings("nls")
	@Override
	public String toString() {
	return "RemoteRefUpdate[remoteName="
	+ remoteName
	+ ", "
	+ status
	+ ", "
	+ (expectedOldObjectId != null ? expectedOldObjectId.name()
	: "(null)") + "..."
	+ (newObjectId != null ? newObjectId.name() : "(null)")
	+ (fastForward ? ", fastForward" : "")
	+ ", srcRef=" + srcRef
	+ (forceUpdate ? ", forceUpdate" : "") + ", message="
	+ (message != null ? "\"" + message + "\"" : "null") + "]";
	}
	}