org.eclipse.jgit/src/org/eclipse/jgit/api/CommitCommand.java

/*
 * Copyright (C) 2010, Christian Halstrick <christian.halstrick@sap.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.
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package org.eclipse.jgit.api;

import java.io.IOException;

import org.eclipse.jgit.dircache.DirCache;
import org.eclipse.jgit.errors.UnmergedPathException;
import org.eclipse.jgit.lib.Commit;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectWriter;
import org.eclipse.jgit.lib.PersonIdent;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.RefUpdate;
import org.eclipse.jgit.lib.RefUpdate.Result;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevWalk;

/**
 * A class used to execute a {@code Commit} command. It has setters for all
 * supported options and arguments of this command and a {@link #call()} method
 * to finally execute the command.
 *
 * @see <a
 *      href="http://www.kernel.org/pub/software/scm/git/docs/git-commit.html"
 *      >Git documentation about Commit</a>
 */
public class CommitCommand extends GitCommand<RevCommit> {
	private PersonIdent author;

	private PersonIdent committer;

	private String message;

	/**
	 * @param repo
	 */
	protected CommitCommand(Repository repo) {
		super(repo);
	}

	/**
	 * Executes the {@code commit} command with all the options and parameters
	 * collected by the setter methods of this class. Each instance of this
	 * class should only be used for one invocation of the command (means: one
	 * call to {@link #call()})
	 *
	 * @return a {@link Commit} object representing the successful commit
	 * @throws NoHeadException
	 *             when called on a git repo without a HEAD reference
	 * @throws NoMessageException
	 *             when called without specifying a commit message
	 * @throws UnmergedPathException
	 *             when the current index contained unmerged pathes (conflicts)
	 * @throws JGitInternalException
	 *             a low-level exception of JGit has occurred. The original
	 *             exception can be retrieved by calling
	 *             {@link Exception#getCause()}. Expect only
	 *             {@code IOException's} to be wrapped. Subclasses of
	 *             {@link IOException} (e.g. {@link UnmergedPathException}) are
	 *             typically not wrapped here but thrown as original exception
	 */
	public RevCommit call() throws NoHeadException, NoMessageException,
			UnmergedPathException, ConcurrentRefUpdateException,
			JGitInternalException {
		checkCallable();
		processOptions();

		try {
			Ref head = repo.getRef(Constants.HEAD);
			if (head == null)
				throw new NoHeadException(
						"Commit on repo without HEAD currently not supported");

			// determine the current HEAD and the commit it is referring to
			ObjectId parentID = repo.resolve(Constants.HEAD + "^{commit}");

			// lock the index
			DirCache index = DirCache.lock(repo);
			try {
				ObjectWriter repoWriter = new ObjectWriter(repo);

				// Write the index as tree to the object database. This may fail
				// for example when the index contains unmerged pathes
				// (unresolved conflicts)
				ObjectId indexTreeId = index.writeTree(repoWriter);

				// Create a Commit object, populate it and write it
				Commit commit = new Commit(repo);
				commit.setCommitter(committer);
				commit.setAuthor(author);
				commit.setMessage(message);
				if (parentID != null)
					commit.setParentIds(new ObjectId[] { parentID });
				commit.setTreeId(indexTreeId);
				ObjectId commitId = repoWriter.writeCommit(commit);

				RevCommit revCommit = new RevWalk(repo).parseCommit(commitId);
				RefUpdate ru = repo.updateRef(Constants.HEAD);
				ru.setNewObjectId(commitId);
				ru.setRefLogMessage("commit : " + revCommit.getShortMessage(),
						false);

				ru.setExpectedOldObjectId(parentID);
				Result rc = ru.update();
				switch (rc) {
				case NEW:
				case FAST_FORWARD:
					setCallable(false);
					return revCommit;
				case REJECTED:
				case LOCK_FAILURE:
					throw new ConcurrentRefUpdateException(
							"Could lock HEAD during commit", ru.getRef(), rc);
				default:
					throw new JGitInternalException(
							"Updating the ref "
									+ Constants.HEAD
									+ " to "
									+ commitId.toString()
									+ " failed. ReturnCode from RefUpdate.update() was "
									+ rc);
				}
			} finally {
				index.unlock();
			}
		} catch (UnmergedPathException e) {
			// since UnmergedPathException is a subclass of IOException
			// which should not be wrapped by a JGitInternalException we
			// have to catch and re-throw it here
			throw e;
		} catch (IOException e) {
			throw new JGitInternalException(
					"Exception caught during execution of commit command", e);
		}
	}

	/**
	 * Sets default values for not explicitly specified options. Then validates
	 * that all required data has been provided.
	 *
	 * @throws NoMessageException
	 *             if the commit message has not been specified
	 */
	private void processOptions() throws NoMessageException {
		if (message == null)
			// as long as we don't suppport -C option we have to have
			// an explicit message
			throw new NoMessageException("commit message not specified");
		if (committer == null)
			committer = new PersonIdent(repo);
		if (author == null)
			author = committer;
	}

	/**
	 * @param message
	 *            the commit message used for the {@code commit}
	 * @return {@code this}
	 */
	public CommitCommand setMessage(String message) {
		checkCallable();
		this.message = message;
		return this;
	}

	/**
	 * @return the commit message used for the <code>commit</code>
	 */
	public String getMessage() {
		return message;
	}

	/**
	 * Sets the committer for this {@code commit}. If no committer is explicitly
	 * specified because this method is never called or called with {@code null}
	 * value then the committer will be deduced from config info in repository,
	 * with current time.
	 *
	 * @param committer
	 *            the committer used for the {@code commit}
	 * @return {@code this}
	 */
	public CommitCommand setCommitter(PersonIdent committer) {
		checkCallable();
		this.committer = committer;
		return this;
	}

	/**
	 * Sets the committer for this {@code commit}. If no committer is explicitly
	 * specified because this method is never called or called with {@code null}
	 * value then the committer will be deduced from config info in repository,
	 * with current time.
	 *
	 * @param name
	 *            the name of the committer used for the {@code commit}
	 * @param email
	 *            the email of the committer used for the {@code commit}
	 * @return {@code this}
	 */
	public CommitCommand setCommitter(String name, String email) {
		checkCallable();
		return setCommitter(new PersonIdent(name, email));
	}

	/**
	 * @return the committer used for the {@code commit}. If no committer was
	 *         specified {@code null} is returned and the default
	 *         {@link PersonIdent} of this repo is used during execution of the
	 *         command
	 */
	public PersonIdent getCommitter() {
		return committer;
	}

	/**
	 * Sets the author for this {@code commit}. If no author is explicitly
	 * specified because this method is never called or called with {@code null}
	 * value then the author will be set to the committer.
	 *
	 * @param author
	 *            the author used for the {@code commit}
	 * @return {@code this}
	 */
	public CommitCommand setAuthor(PersonIdent author) {
		checkCallable();
		this.author = author;
		return this;
	}

	/**
	 * Sets the author for this {@code commit}. If no author is explicitly
	 * specified because this method is never called or called with {@code null}
	 * value then the author will be set to the committer.
	 *
	 * @param name
	 *            the name of the author used for the {@code commit}
	 * @param email
	 *            the email of the author used for the {@code commit}
	 * @return {@code this}
	 */
	public CommitCommand setAuthor(String name, String email) {
		checkCallable();
		return setAuthor(new PersonIdent(name, email));
	}

	/**
	 * @return the author used for the {@code commit}. If no author was
	 *         specified {@code null} is returned and the default
	 *         {@link PersonIdent} of this repo is used during execution of the
	 *         command
	 */
	public PersonIdent getAuthor() {
		return author;
	}
}