MergeCommand.java
/*
* Copyright (C) 2010, Christian Halstrick <christian.halstrick@sap.com>
* Copyright (C) 2010, 2014, Stefan Lay <stefan.lay@sap.com>
* Copyright (C) 2016, 2021 Laurent Delaigue <laurent.delaigue@obeo.fr> and others
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Distribution License v. 1.0 which is available at
* https://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
package org.eclipse.jgit.api;
import java.io.IOException;
import java.text.MessageFormat;
import java.util.Arrays;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import org.eclipse.jgit.annotations.Nullable;
import org.eclipse.jgit.api.MergeResult.MergeStatus;
import org.eclipse.jgit.api.errors.CheckoutConflictException;
import org.eclipse.jgit.api.errors.ConcurrentRefUpdateException;
import org.eclipse.jgit.api.errors.GitAPIException;
import org.eclipse.jgit.api.errors.InvalidMergeHeadsException;
import org.eclipse.jgit.api.errors.JGitInternalException;
import org.eclipse.jgit.api.errors.NoHeadException;
import org.eclipse.jgit.api.errors.NoMessageException;
import org.eclipse.jgit.api.errors.WrongRepositoryStateException;
import org.eclipse.jgit.dircache.DirCacheCheckout;
import org.eclipse.jgit.events.WorkingTreeModifiedEvent;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.AnyObjectId;
import org.eclipse.jgit.lib.Config.ConfigEnum;
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.RefUpdate;
import org.eclipse.jgit.lib.RefUpdate.Result;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.merge.ContentMergeStrategy;
import org.eclipse.jgit.merge.MergeConfig;
import org.eclipse.jgit.merge.MergeMessageFormatter;
import org.eclipse.jgit.merge.MergeStrategy;
import org.eclipse.jgit.merge.Merger;
import org.eclipse.jgit.merge.ResolveMerger;
import org.eclipse.jgit.merge.ResolveMerger.MergeFailureReason;
import org.eclipse.jgit.merge.SquashMessageFormatter;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.revwalk.RevWalkUtils;
import org.eclipse.jgit.treewalk.FileTreeIterator;
import org.eclipse.jgit.util.StringUtils;
/**
* A class used to execute a {@code Merge} 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-merge.html"
* >Git documentation about Merge</a>
*/
public class MergeCommand extends GitCommand<MergeResult> {
private MergeStrategy mergeStrategy = MergeStrategy.RECURSIVE;
private ContentMergeStrategy contentStrategy;
private List<Ref> commits = new LinkedList<>();
private Boolean squash;
private FastForwardMode fastForwardMode;
private String message;
private boolean insertChangeId;
private ProgressMonitor monitor = NullProgressMonitor.INSTANCE;
/**
* Values for the "merge.conflictStyle" git config.
*
* @since 5.12
*/
public enum ConflictStyle {
/** "merge" style: only ours/theirs. This is the default. */
MERGE,
/** "diff3" style: ours/base/theirs. */
DIFF3
}
/**
* The modes available for fast forward merges corresponding to the
* <code>--ff</code>, <code>--no-ff</code> and <code>--ff-only</code>
* options under <code>branch.<name>.mergeoptions</code>.
*/
public enum FastForwardMode implements ConfigEnum {
/**
* Corresponds to the default --ff option (for a fast forward update the
* branch pointer only).
*/
FF,
/**
* Corresponds to the --no-ff option (create a merge commit even for a
* fast forward).
*/
NO_FF,
/**
* Corresponds to the --ff-only option (abort unless the merge is a fast
* forward).
*/
FF_ONLY;
@Override
public String toConfigValue() {
return "--" + name().toLowerCase(Locale.ROOT).replace('_', '-'); //$NON-NLS-1$
}
@Override
public boolean matchConfigValue(String in) {
if (StringUtils.isEmptyOrNull(in))
return false;
if (!in.startsWith("--")) //$NON-NLS-1$
return false;
return name().equalsIgnoreCase(in.substring(2).replace('-', '_'));
}
/**
* The modes available for fast forward merges corresponding to the
* options under <code>merge.ff</code>.
*/
public enum Merge {
/**
* {@link FastForwardMode#FF}.
*/
TRUE,
/**
* {@link FastForwardMode#NO_FF}.
*/
FALSE,
/**
* {@link FastForwardMode#FF_ONLY}.
*/
ONLY;
/**
* Map from <code>FastForwardMode</code> to
* <code>FastForwardMode.Merge</code>.
*
* @param ffMode
* the <code>FastForwardMode</code> value to be mapped
* @return the mapped <code>FastForwardMode.Merge</code> value
*/
public static Merge valueOf(FastForwardMode ffMode) {
switch (ffMode) {
case NO_FF:
return FALSE;
case FF_ONLY:
return ONLY;
default:
return TRUE;
}
}
}
/**
* Map from <code>FastForwardMode.Merge</code> to
* <code>FastForwardMode</code>.
*
* @param ffMode
* the <code>FastForwardMode.Merge</code> value to be mapped
* @return the mapped <code>FastForwardMode</code> value
*/
public static FastForwardMode valueOf(FastForwardMode.Merge ffMode) {
switch (ffMode) {
case FALSE:
return NO_FF;
case ONLY:
return FF_ONLY;
default:
return FF;
}
}
}
private Boolean commit;
/**
* Constructor for MergeCommand.
*
* @param repo
* the {@link org.eclipse.jgit.lib.Repository}
*/
protected MergeCommand(Repository repo) {
super(repo);
}
/**
* {@inheritDoc}
* <p>
* Execute the {@code Merge} 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
@SuppressWarnings("boxing")
public MergeResult call() throws GitAPIException, NoHeadException,
ConcurrentRefUpdateException, CheckoutConflictException,
InvalidMergeHeadsException, WrongRepositoryStateException, NoMessageException {
checkCallable();
fallBackToConfiguration();
checkParameters();
DirCacheCheckout dco = null;
try (RevWalk revWalk = new RevWalk(repo)) {
Ref head = repo.exactRef(Constants.HEAD);
if (head == null)
throw new NoHeadException(
JGitText.get().commitOnRepoWithoutHEADCurrentlyNotSupported);
StringBuilder refLogMessage = new StringBuilder("merge "); //$NON-NLS-1$
// Check for FAST_FORWARD, ALREADY_UP_TO_DATE
// we know for now there is only one commit
Ref ref = commits.get(0);
refLogMessage.append(ref.getName());
// handle annotated tags
ref = repo.getRefDatabase().peel(ref);
ObjectId objectId = ref.getPeeledObjectId();
if (objectId == null)
objectId = ref.getObjectId();
RevCommit srcCommit = revWalk.lookupCommit(objectId);
ObjectId headId = head.getObjectId();
if (headId == null) {
revWalk.parseHeaders(srcCommit);
dco = new DirCacheCheckout(repo,
repo.lockDirCache(), srcCommit.getTree());
dco.setFailOnConflict(true);
dco.setProgressMonitor(monitor);
dco.checkout();
RefUpdate refUpdate = repo
.updateRef(head.getTarget().getName());
refUpdate.setNewObjectId(objectId);
refUpdate.setExpectedOldObjectId(null);
refUpdate.setRefLogMessage("initial pull", false); //$NON-NLS-1$
if (refUpdate.update() != Result.NEW)
throw new NoHeadException(
JGitText.get().commitOnRepoWithoutHEADCurrentlyNotSupported);
setCallable(false);
return new MergeResult(srcCommit, srcCommit, new ObjectId[] {
null, srcCommit }, MergeStatus.FAST_FORWARD,
mergeStrategy, null, null);
}
RevCommit headCommit = revWalk.lookupCommit(headId);
if (revWalk.isMergedInto(srcCommit, headCommit)) {
setCallable(false);
return new MergeResult(headCommit, srcCommit, new ObjectId[] {
headCommit, srcCommit },
MergeStatus.ALREADY_UP_TO_DATE, mergeStrategy, null, null);
} else if (revWalk.isMergedInto(headCommit, srcCommit)
&& fastForwardMode != FastForwardMode.NO_FF) {
// FAST_FORWARD detected: skip doing a real merge but only
// update HEAD
refLogMessage.append(": " + MergeStatus.FAST_FORWARD); //$NON-NLS-1$
dco = new DirCacheCheckout(repo,
headCommit.getTree(), repo.lockDirCache(),
srcCommit.getTree());
dco.setProgressMonitor(monitor);
dco.setFailOnConflict(true);
dco.checkout();
String msg = null;
ObjectId newHead, base = null;
MergeStatus mergeStatus = null;
if (!squash) {
updateHead(refLogMessage, srcCommit, headId);
newHead = base = srcCommit;
mergeStatus = MergeStatus.FAST_FORWARD;
} else {
msg = JGitText.get().squashCommitNotUpdatingHEAD;
newHead = base = headId;
mergeStatus = MergeStatus.FAST_FORWARD_SQUASHED;
List<RevCommit> squashedCommits = RevWalkUtils.find(
revWalk, srcCommit, headCommit);
String squashMessage = new SquashMessageFormatter().format(
squashedCommits, head);
repo.writeSquashCommitMsg(squashMessage);
}
setCallable(false);
return new MergeResult(newHead, base, new ObjectId[] {
headCommit, srcCommit }, mergeStatus, mergeStrategy,
null, msg);
} else {
if (fastForwardMode == FastForwardMode.FF_ONLY) {
return new MergeResult(headCommit, srcCommit,
new ObjectId[] { headCommit, srcCommit },
MergeStatus.ABORTED, mergeStrategy, null, null);
}
String mergeMessage = ""; //$NON-NLS-1$
if (!squash) {
if (message != null)
mergeMessage = message;
else
mergeMessage = new MergeMessageFormatter().format(
commits, head);
repo.writeMergeCommitMsg(mergeMessage);
repo.writeMergeHeads(Arrays.asList(ref.getObjectId()));
} else {
List<RevCommit> squashedCommits = RevWalkUtils.find(
revWalk, srcCommit, headCommit);
String squashMessage = new SquashMessageFormatter().format(
squashedCommits, head);
repo.writeSquashCommitMsg(squashMessage);
}
Merger merger = mergeStrategy.newMerger(repo);
merger.setProgressMonitor(monitor);
boolean noProblems;
Map<String, org.eclipse.jgit.merge.MergeResult<?>> lowLevelResults = null;
Map<String, MergeFailureReason> failingPaths = null;
List<String> unmergedPaths = null;
if (merger instanceof ResolveMerger) {
ResolveMerger resolveMerger = (ResolveMerger) merger;
resolveMerger.setContentMergeStrategy(contentStrategy);
resolveMerger.setCommitNames(new String[] {
"BASE", "HEAD", ref.getName() }); //$NON-NLS-1$ //$NON-NLS-2$
resolveMerger.setWorkingTreeIterator(new FileTreeIterator(repo));
noProblems = merger.merge(headCommit, srcCommit);
lowLevelResults = resolveMerger
.getMergeResults();
failingPaths = resolveMerger.getFailingPaths();
unmergedPaths = resolveMerger.getUnmergedPaths();
if (!resolveMerger.getModifiedFiles().isEmpty()) {
repo.fireEvent(new WorkingTreeModifiedEvent(
resolveMerger.getModifiedFiles(), null));
}
} else
noProblems = merger.merge(headCommit, srcCommit);
refLogMessage.append(": Merge made by "); //$NON-NLS-1$
if (!revWalk.isMergedInto(headCommit, srcCommit))
refLogMessage.append(mergeStrategy.getName());
else
refLogMessage.append("recursive"); //$NON-NLS-1$
refLogMessage.append('.');
if (noProblems) {
dco = new DirCacheCheckout(repo,
headCommit.getTree(), repo.lockDirCache(),
merger.getResultTreeId());
dco.setFailOnConflict(true);
dco.setProgressMonitor(monitor);
dco.checkout();
String msg = null;
ObjectId newHeadId = null;
MergeStatus mergeStatus = null;
if (!commit && squash) {
mergeStatus = MergeStatus.MERGED_SQUASHED_NOT_COMMITTED;
}
if (!commit && !squash) {
mergeStatus = MergeStatus.MERGED_NOT_COMMITTED;
}
if (commit && !squash) {
try (Git git = new Git(getRepository())) {
newHeadId = git.commit()
.setReflogComment(refLogMessage.toString())
.setInsertChangeId(insertChangeId)
.call().getId();
}
mergeStatus = MergeStatus.MERGED;
getRepository().autoGC(monitor);
}
if (commit && squash) {
msg = JGitText.get().squashCommitNotUpdatingHEAD;
newHeadId = headCommit.getId();
mergeStatus = MergeStatus.MERGED_SQUASHED;
}
return new MergeResult(newHeadId, null,
new ObjectId[] { headCommit.getId(),
srcCommit.getId() }, mergeStatus,
mergeStrategy, null, msg);
}
if (failingPaths != null) {
repo.writeMergeCommitMsg(null);
repo.writeMergeHeads(null);
return new MergeResult(null, merger.getBaseCommitId(),
new ObjectId[] { headCommit.getId(),
srcCommit.getId() },
MergeStatus.FAILED, mergeStrategy, lowLevelResults,
failingPaths, null);
}
String mergeMessageWithConflicts = new MergeMessageFormatter()
.formatWithConflicts(mergeMessage, unmergedPaths, '#');
repo.writeMergeCommitMsg(mergeMessageWithConflicts);
return new MergeResult(null, merger.getBaseCommitId(),
new ObjectId[] { headCommit.getId(),
srcCommit.getId() },
MergeStatus.CONFLICTING, mergeStrategy, lowLevelResults,
null);
}
} catch (org.eclipse.jgit.errors.CheckoutConflictException e) {
List<String> conflicts = (dco == null) ? Collections
.<String> emptyList() : dco.getConflicts();
throw new CheckoutConflictException(conflicts, e);
} catch (IOException e) {
throw new JGitInternalException(
MessageFormat.format(
JGitText.get().exceptionCaughtDuringExecutionOfMergeCommand,
e), e);
}
}
private void checkParameters() throws InvalidMergeHeadsException {
if (squash.booleanValue() && fastForwardMode == FastForwardMode.NO_FF) {
throw new JGitInternalException(
JGitText.get().cannotCombineSquashWithNoff);
}
if (commits.size() != 1)
throw new InvalidMergeHeadsException(
commits.isEmpty() ? JGitText.get().noMergeHeadSpecified
: MessageFormat.format(
JGitText.get().mergeStrategyDoesNotSupportHeads,
mergeStrategy.getName(),
Integer.valueOf(commits.size())));
}
/**
* Use values from the configuration if they have not been explicitly
* defined via the setters
*/
private void fallBackToConfiguration() {
MergeConfig config = MergeConfig.getConfigForCurrentBranch(repo);
if (squash == null)
squash = Boolean.valueOf(config.isSquash());
if (commit == null)
commit = Boolean.valueOf(config.isCommit());
if (fastForwardMode == null)
fastForwardMode = config.getFastForwardMode();
}
private void updateHead(StringBuilder refLogMessage, ObjectId newHeadId,
ObjectId oldHeadID) throws IOException,
ConcurrentRefUpdateException {
RefUpdate refUpdate = repo.updateRef(Constants.HEAD);
refUpdate.setNewObjectId(newHeadId);
refUpdate.setRefLogMessage(refLogMessage.toString(), false);
refUpdate.setExpectedOldObjectId(oldHeadID);
Result rc = refUpdate.update();
switch (rc) {
case NEW:
case FAST_FORWARD:
return;
case REJECTED:
case LOCK_FAILURE:
throw new ConcurrentRefUpdateException(
JGitText.get().couldNotLockHEAD, refUpdate.getRef(), rc);
default:
throw new JGitInternalException(MessageFormat.format(
JGitText.get().updatingRefFailed, Constants.HEAD,
newHeadId.toString(), rc));
}
}
/**
* Set merge strategy
*
* @param mergeStrategy
* the {@link org.eclipse.jgit.merge.MergeStrategy} to be used
* @return {@code this}
*/
public MergeCommand setStrategy(MergeStrategy mergeStrategy) {
checkCallable();
this.mergeStrategy = mergeStrategy;
return this;
}
/**
* Sets the content merge strategy to use if the
* {@link #setStrategy(MergeStrategy) merge strategy} is "resolve" or
* "recursive".
*
* @param strategy
* the {@link ContentMergeStrategy} to be used
* @return {@code this}
* @since 5.12
*/
public MergeCommand setContentMergeStrategy(ContentMergeStrategy strategy) {
checkCallable();
this.contentStrategy = strategy;
return this;
}
/**
* Reference to a commit to be merged with the current head
*
* @param aCommit
* a reference to a commit which is merged with the current head
* @return {@code this}
*/
public MergeCommand include(Ref aCommit) {
checkCallable();
commits.add(aCommit);
return this;
}
/**
* Id of a commit which is to be merged with the current head
*
* @param aCommit
* the Id of a commit which is merged with the current head
* @return {@code this}
*/
public MergeCommand include(AnyObjectId aCommit) {
return include(aCommit.getName(), aCommit);
}
/**
* Include a commit
*
* @param name
* a name of a {@code Ref} pointing to the commit
* @param aCommit
* the Id of a commit which is merged with the current head
* @return {@code this}
*/
public MergeCommand include(String name, AnyObjectId aCommit) {
return include(new ObjectIdRef.Unpeeled(Storage.LOOSE, name,
aCommit.copy()));
}
/**
* If <code>true</code>, will prepare the next commit in working tree and
* index as if a real merge happened, but do not make the commit or move the
* HEAD. Otherwise, perform the merge and commit the result.
* <p>
* In case the merge was successful but this flag was set to
* <code>true</code> a {@link org.eclipse.jgit.api.MergeResult} with status
* {@link org.eclipse.jgit.api.MergeResult.MergeStatus#MERGED_SQUASHED} or
* {@link org.eclipse.jgit.api.MergeResult.MergeStatus#FAST_FORWARD_SQUASHED}
* is returned.
*
* @param squash
* whether to squash commits or not
* @return {@code this}
* @since 2.0
*/
public MergeCommand setSquash(boolean squash) {
checkCallable();
this.squash = Boolean.valueOf(squash);
return this;
}
/**
* Sets the fast forward mode.
*
* @param fastForwardMode
* corresponds to the --ff/--no-ff/--ff-only options. If
* {@code null} use the value of the {@code merge.ff} option
* configured in git config. If this option is not configured
* --ff is the built-in default.
* @return {@code this}
* @since 2.2
*/
public MergeCommand setFastForward(
@Nullable FastForwardMode fastForwardMode) {
checkCallable();
this.fastForwardMode = fastForwardMode;
return this;
}
/**
* Controls whether the merge command should automatically commit after a
* successful merge
*
* @param commit
* <code>true</code> if this command should commit (this is the
* default behavior). <code>false</code> if this command should
* not commit. In case the merge was successful but this flag was
* set to <code>false</code> a
* {@link org.eclipse.jgit.api.MergeResult} with type
* {@link org.eclipse.jgit.api.MergeResult} with status
* {@link org.eclipse.jgit.api.MergeResult.MergeStatus#MERGED_NOT_COMMITTED}
* is returned
* @return {@code this}
* @since 3.0
*/
public MergeCommand setCommit(boolean commit) {
this.commit = Boolean.valueOf(commit);
return this;
}
/**
* Set the commit message to be used for the merge commit (in case one is
* created)
*
* @param message
* the message to be used for the merge commit
* @return {@code this}
* @since 3.5
*/
public MergeCommand setMessage(String message) {
this.message = message;
return this;
}
/**
* If set to true a change id will be inserted into the commit message
*
* An existing change id is not replaced. An initial change id (I000...)
* will be replaced by the change id.
*
* @param insertChangeId
* whether to insert a change id
* @return {@code this}
* @since 5.0
*/
public MergeCommand setInsertChangeId(boolean insertChangeId) {
checkCallable();
this.insertChangeId = insertChangeId;
return this;
}
/**
* The progress monitor associated with the diff operation. By default, this
* is set to <code>NullProgressMonitor</code>
*
* @see NullProgressMonitor
* @param monitor
* A progress monitor
* @return this instance
* @since 4.2
*/
public MergeCommand setProgressMonitor(ProgressMonitor monitor) {
if (monitor == null) {
monitor = NullProgressMonitor.INSTANCE;
}
this.monitor = monitor;
return this;
}
}