org.eclipse.jgit.api.CherryPickCommand.java Source code

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/*
 * 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.
 */
package org.eclipse.jgit.api;

import java.io.IOException;
import java.text.MessageFormat;
import java.util.LinkedList;
import java.util.List;

import org.eclipse.jgit.api.errors.ConcurrentRefUpdateException;
import org.eclipse.jgit.api.errors.GitAPIException;
import org.eclipse.jgit.api.errors.JGitInternalException;
import org.eclipse.jgit.api.errors.MultipleParentsNotAllowedException;
import org.eclipse.jgit.api.errors.NoHeadException;
import org.eclipse.jgit.api.errors.NoMessageException;
import org.eclipse.jgit.api.errors.UnmergedPathsException;
import org.eclipse.jgit.api.errors.WrongRepositoryStateException;
import org.eclipse.jgit.dircache.DirCacheCheckout;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.events.WorkingTreeModifiedEvent;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.AnyObjectId;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.NullProgressMonitor;
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.Repository;
import org.eclipse.jgit.merge.MergeMessageFormatter;
import org.eclipse.jgit.merge.MergeStrategy;
import org.eclipse.jgit.merge.ResolveMerger;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.treewalk.FileTreeIterator;

/**
 * A class used to execute a {@code cherry-pick} command. It has setters for all
 * supported options and arguments of this command and a {@link #call()} method
 * to finally execute the command. Each instance of this class should only be
 * used for one invocation of the command (means: one call to {@link #call()})
 *
 * @see <a
 *      href="http://www.kernel.org/pub/software/scm/git/docs/git-cherry-pick.html"
 *      >Git documentation about cherry-pick</a>
 */
public class CherryPickCommand extends GitCommand<CherryPickResult> {
    private String reflogPrefix = "cherry-pick:"; //$NON-NLS-1$

    private List<Ref> commits = new LinkedList<>();

    private String ourCommitName = null;

    private MergeStrategy strategy = MergeStrategy.RECURSIVE;

    private Integer mainlineParentNumber;

    private boolean noCommit = false;

    private ProgressMonitor monitor = NullProgressMonitor.INSTANCE;

    /**
     * Constructor for CherryPickCommand
     *
     * @param repo
     *            the {@link org.eclipse.jgit.lib.Repository}
     */
    protected CherryPickCommand(Repository repo) {
        super(repo);
    }

    /**
     * {@inheritDoc}
     * <p>
     * Executes the {@code Cherry-Pick} command with all the options and
     * parameters collected by the setter methods (e.g. {@link #include(Ref)} of
     * this class. Each instance of this class should only be used for one
     * invocation of the command. Don't call this method twice on an instance.
     */
    @Override
    public CherryPickResult call() throws GitAPIException, NoMessageException, UnmergedPathsException,
            ConcurrentRefUpdateException, WrongRepositoryStateException, NoHeadException {
        RevCommit newHead = null;
        List<Ref> cherryPickedRefs = new LinkedList<>();
        checkCallable();

        try (RevWalk revWalk = new RevWalk(repo)) {

            // get the head commit
            Ref headRef = repo.exactRef(Constants.HEAD);
            if (headRef == null) {
                throw new NoHeadException(JGitText.get().commitOnRepoWithoutHEADCurrentlyNotSupported);
            }

            newHead = revWalk.parseCommit(headRef.getObjectId());

            // loop through all refs to be cherry-picked
            for (Ref src : commits) {
                // get the commit to be cherry-picked
                // handle annotated tags
                ObjectId srcObjectId = src.getPeeledObjectId();
                if (srcObjectId == null) {
                    srcObjectId = src.getObjectId();
                }
                RevCommit srcCommit = revWalk.parseCommit(srcObjectId);

                // get the parent of the commit to cherry-pick
                final RevCommit srcParent = getParentCommit(srcCommit, revWalk);

                String ourName = calculateOurName(headRef);
                String cherryPickName = srcCommit.getId().abbreviate(7).name() + " " + srcCommit.getShortMessage(); //$NON-NLS-1$

                ResolveMerger merger = (ResolveMerger) strategy.newMerger(repo);
                merger.setWorkingTreeIterator(new FileTreeIterator(repo));
                merger.setBase(srcParent.getTree());
                merger.setCommitNames(new String[] { "BASE", ourName, //$NON-NLS-1$
                        cherryPickName });
                if (merger.merge(newHead, srcCommit)) {
                    if (!merger.getModifiedFiles().isEmpty()) {
                        repo.fireEvent(new WorkingTreeModifiedEvent(merger.getModifiedFiles(), null));
                    }
                    if (AnyObjectId.isEqual(newHead.getTree().getId(), merger.getResultTreeId())) {
                        continue;
                    }
                    DirCacheCheckout dco = new DirCacheCheckout(repo, newHead.getTree(), repo.lockDirCache(),
                            merger.getResultTreeId());
                    dco.setFailOnConflict(true);
                    dco.setProgressMonitor(monitor);
                    dco.checkout();
                    if (!noCommit) {
                        newHead = new Git(getRepository()).commit().setMessage(srcCommit.getFullMessage())
                                .setReflogComment(reflogPrefix + " " //$NON-NLS-1$
                                        + srcCommit.getShortMessage())
                                .setAuthor(srcCommit.getAuthorIdent()).setNoVerify(true).call();
                    }
                    cherryPickedRefs.add(src);
                } else {
                    if (merger.failed()) {
                        return new CherryPickResult(merger.getFailingPaths());
                    }

                    // there are merge conflicts

                    String message = new MergeMessageFormatter().formatWithConflicts(srcCommit.getFullMessage(),
                            merger.getUnmergedPaths());

                    if (!noCommit) {
                        repo.writeCherryPickHead(srcCommit.getId());
                    }
                    repo.writeMergeCommitMsg(message);

                    repo.fireEvent(new WorkingTreeModifiedEvent(merger.getModifiedFiles(), null));

                    return CherryPickResult.CONFLICT;
                }
            }
        } catch (IOException e) {
            throw new JGitInternalException(
                    MessageFormat.format(JGitText.get().exceptionCaughtDuringExecutionOfCherryPickCommand, e), e);
        }
        return new CherryPickResult(newHead, cherryPickedRefs);
    }

    private RevCommit getParentCommit(RevCommit srcCommit, RevWalk revWalk)
            throws MultipleParentsNotAllowedException, MissingObjectException, IOException {
        final RevCommit srcParent;
        if (mainlineParentNumber == null) {
            if (srcCommit.getParentCount() != 1)
                throw new MultipleParentsNotAllowedException(
                        MessageFormat.format(JGitText.get().canOnlyCherryPickCommitsWithOneParent, srcCommit.name(),
                                Integer.valueOf(srcCommit.getParentCount())));
            srcParent = srcCommit.getParent(0);
        } else {
            if (mainlineParentNumber.intValue() > srcCommit.getParentCount()) {
                throw new JGitInternalException(MessageFormat.format(JGitText.get().commitDoesNotHaveGivenParent,
                        srcCommit, mainlineParentNumber));
            }
            srcParent = srcCommit.getParent(mainlineParentNumber.intValue() - 1);
        }

        revWalk.parseHeaders(srcParent);
        return srcParent;
    }

    /**
     * Include a reference to a commit
     *
     * @param commit
     *            a reference to a commit which is cherry-picked to the current
     *            head
     * @return {@code this}
     */
    public CherryPickCommand include(Ref commit) {
        checkCallable();
        commits.add(commit);
        return this;
    }

    /**
     * Include a commit
     *
     * @param commit
     *            the Id of a commit which is cherry-picked to the current head
     * @return {@code this}
     */
    public CherryPickCommand include(AnyObjectId commit) {
        return include(commit.getName(), commit);
    }

    /**
     * Include a commit
     *
     * @param name
     *            a name given to the commit
     * @param commit
     *            the Id of a commit which is cherry-picked to the current head
     * @return {@code this}
     */
    public CherryPickCommand include(String name, AnyObjectId commit) {
        return include(new ObjectIdRef.Unpeeled(Storage.LOOSE, name, commit.copy()));
    }

    /**
     * Set the name that should be used in the "OURS" place for conflict markers
     *
     * @param ourCommitName
     *            the name that should be used in the "OURS" place for conflict
     *            markers
     * @return {@code this}
     */
    public CherryPickCommand setOurCommitName(String ourCommitName) {
        this.ourCommitName = ourCommitName;
        return this;
    }

    /**
     * Set the prefix to use in the reflog.
     * <p>
     * This is primarily needed for implementing rebase in terms of
     * cherry-picking
     *
     * @param prefix
     *            including ":"
     * @return {@code this}
     * @since 3.1
     */
    public CherryPickCommand setReflogPrefix(String prefix) {
        this.reflogPrefix = prefix;
        return this;
    }

    /**
     * Set the {@code MergeStrategy}
     *
     * @param strategy
     *            The merge strategy to use during this Cherry-pick.
     * @return {@code this}
     * @since 3.4
     */
    public CherryPickCommand setStrategy(MergeStrategy strategy) {
        this.strategy = strategy;
        return this;
    }

    /**
     * Set the (1-based) parent number to diff against
     *
     * @param mainlineParentNumber
     *            the (1-based) parent number to diff against. This allows
     *            cherry-picking of merges.
     * @return {@code this}
     * @since 3.4
     */
    public CherryPickCommand setMainlineParentNumber(int mainlineParentNumber) {
        this.mainlineParentNumber = Integer.valueOf(mainlineParentNumber);
        return this;
    }

    /**
     * Allows cherry-picking changes without committing them.
     * <p>
     * NOTE: The behavior of cherry-pick is undefined if you pick multiple
     * commits or if HEAD does not match the index state before cherry-picking.
     *
     * @param noCommit
     *            true to cherry-pick without committing, false to commit after
     *            each pick (default)
     * @return {@code this}
     * @since 3.5
     */
    public CherryPickCommand setNoCommit(boolean noCommit) {
        this.noCommit = noCommit;
        return this;
    }

    /**
     * The progress monitor associated with the cherry-pick operation. By
     * default, this is set to <code>NullProgressMonitor</code>
     *
     * @see NullProgressMonitor
     * @param monitor
     *            a {@link org.eclipse.jgit.lib.ProgressMonitor}
     * @return {@code this}
     * @since 4.11
     */
    public CherryPickCommand setProgressMonitor(ProgressMonitor monitor) {
        if (monitor == null) {
            monitor = NullProgressMonitor.INSTANCE;
        }
        this.monitor = monitor;
        return this;
    }

    private String calculateOurName(Ref headRef) {
        if (ourCommitName != null)
            return ourCommitName;

        String targetRefName = headRef.getTarget().getName();
        String headName = Repository.shortenRefName(targetRefName);
        return headName;
    }

    /** {@inheritDoc} */
    @SuppressWarnings("nls")
    @Override
    public String toString() {
        return "CherryPickCommand [repo=" + repo + ",\ncommits=" + commits + ",\nmainlineParentNumber="
                + mainlineParentNumber + ", noCommit=" + noCommit + ", ourCommitName=" + ourCommitName
                + ", reflogPrefix=" + reflogPrefix + ", strategy=" + strategy + "]";
    }

}