org.eclipse.jgit.merge

Class ResolveMerger

java.lang.Object

org.eclipse.jgit.merge.Merger

org.eclipse.jgit.merge.ThreeWayMerger

org.eclipse.jgit.merge.ResolveMerger

Direct Known Subclasses:

RecursiveMerger

public class ResolveMerger
extends ThreeWayMerger

A three-way merger performing a content-merge if necessary

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ResolveMerger.MergeFailureReason If the merge fails (means: not stopped because of unresolved conflicts) this enum is used to explain why it failed

Field Summary

Fields

Modifier and Type	Field and Description
protected DirCacheBuilder	builder Builder to update the cache during this merge.
protected String[]	commitNames string versions of a list of commit SHA1s
protected DirCache	dircache Directory cache
protected boolean	enterSubtree Updated as we merge entries of the tree walk.
protected Map<String,ResolveMerger.MergeFailureReason>	failingPaths Paths for which the merge failed altogether.
protected boolean	implicitDirCache Set to true if this merger should use the default dircache of the repository and should handle locking and unlocking of the dircache.
protected boolean	inCore Set to true if this merge should work in-memory.
protected MergeAlgorithm	mergeAlgorithm our merge algorithm
protected Map<String,MergeResult<? extends Sequence>>	mergeResults Low-level textual merge results.
protected List<String>	modifiedFiles Files modified during this merge operation.
protected ObjectId	resultTree merge result as tree
protected static int	T_BASE Index of the base tree within the tree walk.
protected static int	T_FILE Index of the working directory tree within the tree walk.
protected static int	T_INDEX Index of the index tree within the tree walk.
protected static int	T_OURS Index of our tree in withthe tree walk.
protected static int	T_THEIRS Index of their tree within the tree walk.
protected Map<String,DirCacheEntry>	toBeCheckedOut If the merger has nothing to do for a file but check it out at the end of the operation, it can be added here.
protected List<String>	toBeDeleted Paths in this list will be deleted from the local copy at the end of the operation.
protected NameConflictTreeWalk	tw The tree walk which we'll iterate over to merge entries.
protected List<String>	unmergedPaths Paths that could not be merged by this merger because of an unsolvable conflict.
protected WorkingTreeIterator	workingTreeIterator The iterator to access the working tree.

Fields inherited from class org.eclipse.jgit.merge.Merger

db, reader, sourceCommits, sourceObjects, sourceTrees, walk

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ResolveMerger(Repository local)
protected	ResolveMerger(Repository local, boolean inCore)

Method Summary

Methods

Modifier and Type	Method and Description
protected void	cleanUp() Reverts the worktree after an unsuccessful merge.
boolean	failed() Returns whether this merge failed (i.e.
String[]	getCommitNames()
Map<String,ResolveMerger.MergeFailureReason>	getFailingPaths()
Map<String,MergeResult<? extends Sequence>>	getMergeResults()
List<String>	getModifiedFiles()
ObjectId	getResultTreeId()
Map<String,DirCacheEntry>	getToBeCheckedOut()
List<String>	getUnmergedPaths()
protected boolean	mergeImpl() Execute the merge.
protected boolean	mergeTrees(AbstractTreeIterator baseTree, RevTree headTree, RevTree mergeTree, boolean ignoreConflicts) The resolve conflict way of three way merging
protected boolean	mergeTreeWalk(TreeWalk treeWalk, boolean ignoreConflicts) Process the given TreeWalk's entries.
protected boolean	processEntry(CanonicalTreeParser base, CanonicalTreeParser ours, CanonicalTreeParser theirs, DirCacheBuildIterator index, WorkingTreeIterator work, boolean ignoreConflicts) Processes one path and tries to merge.
void	setCommitNames(String[] commitNames)
void	setDirCache(DirCache dc) Sets the DirCache which shall be used by this merger.
void	setWorkingTreeIterator(WorkingTreeIterator workingTreeIterator) Sets the WorkingTreeIterator to be used by this merger.

Methods inherited from class org.eclipse.jgit.merge.ThreeWayMerger

getBaseCommitId, merge, mergeBase, setBase

Methods inherited from class org.eclipse.jgit.merge.Merger

getBaseCommit, getBaseCommit, getObjectInserter, getRepository, merge, openTree, setObjectInserter

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

tw

protected NameConflictTreeWalk tw

The tree walk which we'll iterate over to merge entries.

Since:

3.4

commitNames

protected String[] commitNames

string versions of a list of commit SHA1s

Since:

3.0

T_BASE

protected static final int T_BASE

Index of the base tree within the tree walk.

Since:

3.4

See Also:

Constant Field Values

T_OURS

protected static final int T_OURS

Index of our tree in withthe tree walk.

Since:

3.4

See Also:

Constant Field Values

T_THEIRS

protected static final int T_THEIRS

Index of their tree within the tree walk.

Since:

3.4

See Also:

Constant Field Values

T_INDEX

protected static final int T_INDEX

Index of the index tree within the tree walk.

Since:

3.4

See Also:

Constant Field Values

T_FILE

protected static final int T_FILE

Index of the working directory tree within the tree walk.

Since:

3.4

See Also:

Constant Field Values

builder

protected DirCacheBuilder builder

Builder to update the cache during this merge.

Since:

3.4

resultTree

protected ObjectId resultTree

merge result as tree

Since:

3.0

unmergedPaths

protected List<String> unmergedPaths

Paths that could not be merged by this merger because of an unsolvable conflict.

Since:

3.4

modifiedFiles

protected List<String> modifiedFiles

Files modified during this merge operation.

Since:

3.4

toBeCheckedOut

protected Map<String,DirCacheEntry> toBeCheckedOut

If the merger has nothing to do for a file but check it out at the end of the operation, it can be added here.

Since:

3.4

toBeDeleted

protected List<String> toBeDeleted

Paths in this list will be deleted from the local copy at the end of the operation.

Since:

3.4

mergeResults

protected Map<String,MergeResult<? extends Sequence>> mergeResults

Low-level textual merge results. Will be passed on to the callers in case of conflicts.

Since:

3.4

failingPaths

protected Map<String,ResolveMerger.MergeFailureReason> failingPaths

Paths for which the merge failed altogether.

Since:

3.4

enterSubtree

protected boolean enterSubtree

Updated as we merge entries of the tree walk. Tells us whether we should recurse into the entry if it is a subtree.

Since:

3.4

inCore

protected boolean inCore

Set to true if this merge should work in-memory. The repos dircache and workingtree are not touched by this method. Eventually needed files are created as temporary files and a new empty, in-memory dircache will be used instead the repo's one. Often used for bare repos where the repo doesn't even have a workingtree and dircache.

Since:

3.0

implicitDirCache

protected boolean implicitDirCache

Set to true if this merger should use the default dircache of the repository and should handle locking and unlocking of the dircache. If this merger should work in-core or if an explicit dircache was specified during construction then this field is set to false.

Since:

3.0

dircache

protected DirCache dircache

Directory cache

Since:

3.0

workingTreeIterator

protected WorkingTreeIterator workingTreeIterator

The iterator to access the working tree. If set to null this merger will not touch the working tree.

Since:

3.0

mergeAlgorithm

protected MergeAlgorithm mergeAlgorithm

our merge algorithm

Since:

3.0

Constructor Detail

ResolveMerger

protected ResolveMerger(Repository local,
             boolean inCore)

Parameters:

local -

inCore -

ResolveMerger

protected ResolveMerger(Repository local)

Parameters:

local -

Method Detail

mergeImpl

protected boolean mergeImpl()
                     throws IOException

Description copied from class: Merger

Execute the merge.

This method is called from Merger.merge(AnyObjectId[]) after the Merger.sourceObjects, Merger.sourceCommits and Merger.sourceTrees have been populated.

Specified by:

mergeImpl in class Merger

Returns:

true if the merge was completed without conflicts; false if the merge strategy cannot handle this merge or there were conflicts preventing it from automatically resolving all paths.

Throws:

IncorrectObjectTypeException - one of the input objects is not a commit, but the strategy requires it to be a commit.

IOException - one or more sources could not be read, or outputs could not be written to the Repository.

cleanUp

protected void cleanUp()
                throws NoWorkTreeException,
                       CorruptObjectException,
                       IOException

Reverts the worktree after an unsuccessful merge. We know that for all modified files the old content was in the old index and the index contained only stage 0. In case if inCore operation just clear the history of modified files.

Throws:

IOException

CorruptObjectException

NoWorkTreeException

Since:

3.4

processEntry

protected boolean processEntry(CanonicalTreeParser base,
                   CanonicalTreeParser ours,
                   CanonicalTreeParser theirs,
                   DirCacheBuildIterator index,
                   WorkingTreeIterator work,
                   boolean ignoreConflicts)
                        throws MissingObjectException,
                               IncorrectObjectTypeException,
                               CorruptObjectException,
                               IOException

Processes one path and tries to merge. This method will do all do all trivial (not content) merges and will also detect if a merge will fail. The merge will fail when one of the following is true

• the index entry does not match the entry in ours. When merging one branch into the current HEAD, ours will point to HEAD and theirs will point to the other branch. It is assumed that the index matches the HEAD because it will only not match HEAD if it was populated before the merge operation. But the merge commit should not accidentally contain modifications done before the merge. Check the git read-tree documentation for further explanations.
• A conflict was detected and the working-tree file is dirty. When a conflict is detected the content-merge algorithm will try to write a merged version into the working-tree. If the file is dirty we would override unsaved data.

Parameters:

base - the common base for ours and theirs

ours - the ours side of the merge. When merging a branch into the HEAD ours will point to HEAD

theirs - the theirs side of the merge. When merging a branch into the current HEAD theirs will point to the branch which is merged into HEAD.

index - the index entry

work - the file in the working tree

ignoreConflicts - see mergeTrees(AbstractTreeIterator, RevTree, RevTree, boolean)

Returns:

false if the merge will fail because the index entry didn't match ours or the working-dir file was dirty and a conflict occurred

Throws:

MissingObjectException

IncorrectObjectTypeException

CorruptObjectException

IOException

Since:

3.5

getResultTreeId

public ObjectId getResultTreeId()

Specified by:

getResultTreeId in class Merger

Returns:

resulting tree, if Merger.merge(AnyObjectId[]) returned true.

setCommitNames

public void setCommitNames(String[] commitNames)

Parameters:

commitNames - the names of the commits as they would appear in conflict markers

getCommitNames

public String[] getCommitNames()

Returns:

the names of the commits as they would appear in conflict markers.

getUnmergedPaths

public List<String> getUnmergedPaths()

Returns:

the paths with conflicts. This is a subset of the files listed by getModifiedFiles()

getModifiedFiles

public List<String> getModifiedFiles()

Returns:

the paths of files which have been modified by this merge. A file will be modified if a content-merge works on this path or if the merge algorithm decides to take the theirs-version. This is a superset of the files listed by getUnmergedPaths().

getToBeCheckedOut

public Map<String,DirCacheEntry> getToBeCheckedOut()

Returns:

a map which maps the paths of files which have to be checked out because the merge created new fully-merged content for this file into the index. This means: the merge wrote a new stage 0 entry for this path.

getMergeResults

public Map<String,MergeResult<? extends Sequence>> getMergeResults()

Returns:

the mergeResults

getFailingPaths

public Map<String,ResolveMerger.MergeFailureReason> getFailingPaths()

Returns:

lists paths causing this merge to fail (not stopped because of a conflict). null is returned if this merge didn't fail.

failed

public boolean failed()

Returns whether this merge failed (i.e. not stopped because of a conflict)

Returns:

true if a failure occurred, false otherwise

setDirCache

public void setDirCache(DirCache dc)

Sets the DirCache which shall be used by this merger. If the DirCache is not set explicitly and if this merger doesn't work in-core, this merger will implicitly get and lock a default DirCache. If the DirCache is explicitly set the caller is responsible to lock it in advance. Finally the merger will call DirCache.commit() which requires that the DirCache is locked. If the mergeImpl() returns without throwing an exception the lock will be released. In case of exceptions the caller is responsible to release the lock.

Parameters:

dc - the DirCache to set

setWorkingTreeIterator

public void setWorkingTreeIterator(WorkingTreeIterator workingTreeIterator)

Sets the WorkingTreeIterator to be used by this merger. If no WorkingTreeIterator is set this merger will ignore the working tree and fail if a content merge is necessary.

TODO: enhance WorkingTreeIterator to support write operations. Then this merger will be able to merge with a different working tree abstraction.

Parameters:

workingTreeIterator - the workingTreeIt to set

mergeTrees

protected boolean mergeTrees(AbstractTreeIterator baseTree,
                 RevTree headTree,
                 RevTree mergeTree,
                 boolean ignoreConflicts)
                      throws IOException

The resolve conflict way of three way merging

Parameters:

baseTree -

headTree -

mergeTree -

ignoreConflicts - Controls what to do in case a content-merge is done and a conflict is detected. The default setting for this should be false. In this case the working tree file is filled with new content (containing conflict markers) and the index is filled with multiple stages containing BASE, OURS and THEIRS content. Having such non-0 stages is the sign to git tools that there are still conflicts for that path.

If true is specified the behavior is different. In case a conflict is detected the working tree file is again filled with new content (containing conflict markers). But also stage 0 of the index is filled with that content. No other stages are filled. Means: there is no conflict on that path but the new content (including conflict markers) is stored as successful merge result. This is needed in the context of RecursiveMerger where when determining merge bases we don't want to deal with content-merge conflicts.

Returns:

whether the trees merged cleanly

Throws:

IOException

Since:

3.5

mergeTreeWalk

protected boolean mergeTreeWalk(TreeWalk treeWalk,
                    boolean ignoreConflicts)
                         throws IOException

Process the given TreeWalk's entries.

Parameters:

treeWalk - The walk to iterate over.

ignoreConflicts - see mergeTrees(AbstractTreeIterator, RevTree, RevTree, boolean)

Returns:

Whether the trees merged cleanly.

Throws:

IOException

Since:

3.5