Class ResolveMerger

Direct Known Subclasses:
RecursiveMerger

public class ResolveMerger extends ThreeWayMerger
A three-way merger performing a content-merge if necessary
  • Field Details

    • 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:
    • T_OURS

      protected static final int T_OURS
      Index of our tree in withthe tree walk.
      Since:
      3.4
      See Also:
    • T_THEIRS

      protected static final int T_THEIRS
      Index of their tree within the tree walk.
      Since:
      3.4
      See Also:
    • T_INDEX

      protected static final int T_INDEX
      Index of the index tree within the tree walk.
      Since:
      3.4
      See Also:
    • T_FILE

      protected static final int T_FILE
      Index of the working directory tree within the tree walk.
      Since:
      3.4
      See Also:
    • workTreeUpdater

      protected ResolveMerger.WorkTreeUpdater workTreeUpdater
      Handler for repository I/O actions.
      Since:
      6.3
    • resultTree

      protected ObjectId resultTree
      merge result as tree
      Since:
      3.0
    • modifiedFiles

      protected List<String> modifiedFiles
      Files modified during this operation. Note this list is only updated after a successful write.
    • unmergedPaths

      protected List<String> unmergedPaths
      Paths that could not be merged by this merger because of an unsolvable conflict.
      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
    • 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 Details

    • ResolveMerger

      protected ResolveMerger(Repository local, boolean inCore)
      Constructor for ResolveMerger.
      Parameters:
      local - the Repository.
      inCore - a boolean.
    • ResolveMerger

      protected ResolveMerger(Repository local)
      Constructor for ResolveMerger.
      Parameters:
      local - the Repository.
    • ResolveMerger

      protected ResolveMerger(ObjectInserter inserter, Config config)
      Constructor for ResolveMerger.
      Parameters:
      inserter - an ObjectInserter object.
      config - the repository configuration
      Since:
      4.8
  • Method Details

    • getContentMergeStrategy

      @NonNull public ContentMergeStrategy getContentMergeStrategy()
      Retrieves the content merge strategy for content conflicts.
      Returns:
      the ContentMergeStrategy in effect
      Since:
      5.12
    • setContentMergeStrategy

      public void setContentMergeStrategy(ContentMergeStrategy strategy)
      Sets the content merge strategy for content conflicts.
      Parameters:
      strategy - ContentMergeStrategy to use
      Since:
      5.12
    • 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.
    • addToCheckout

      protected void addToCheckout(String path, DirCacheEntry entry, Attributes[] attributes) throws IOException
      Adds a DirCacheEntry for direct checkout and remembers its DirCacheCheckout.CheckoutMetadata.
      Parameters:
      path - of the entry
      entry - to add
      attributes - the Attributes of the trees
      Throws:
      IOException - if the DirCacheCheckout.CheckoutMetadata cannot be determined
      Since:
      6.1
    • addDeletion

      protected void addDeletion(String path, boolean isFile, Attributes attributes) throws IOException
      Remember a path for deletion, and remember its DirCacheCheckout.CheckoutMetadata in case it has to be restored in the cleanUp.
      Parameters:
      path - of the entry
      isFile - whether it is a file
      attributes - to use for determining the DirCacheCheckout.CheckoutMetadata
      Throws:
      IOException - if the DirCacheCheckout.CheckoutMetadata cannot be determined
      Since:
      5.1
    • processEntry

      protected boolean processEntry(CanonicalTreeParser base, CanonicalTreeParser ours, CanonicalTreeParser theirs, DirCacheBuildIterator index, WorkingTreeIterator work, boolean ignoreConflicts, Attributes[] attributes) throws IOException
      Processes one path and tries to merge taking git attributes in account. This method will 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)
      attributes - the Attributes for the three trees
      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:
      IOException - if an IO error occurred
      Since:
      6.1
    • getResultTreeId

      public ObjectId getResultTreeId()
      Description copied from class: Merger
      Get resulting tree.
      Specified by:
      getResultTreeId in class Merger
      Returns:
      resulting tree, if Merger.merge(AnyObjectId[]) returned true.
    • setCommitNames

      public void setCommitNames(String[] commitNames)
      Set the names of the commits as they would appear in conflict markers
      Parameters:
      commitNames - the names of the commits as they would appear in conflict markers
    • getCommitNames

      public String[] getCommitNames()
      Get the names of the commits as they would appear in conflict markers.
      Returns:
      the names of the commits as they would appear in conflict markers.
    • getUnmergedPaths

      public List<String> getUnmergedPaths()
      Get the paths with conflicts. This is a subset of the files listed by getModifiedFiles()
      Returns:
      the paths with conflicts. This is a subset of the files listed by getModifiedFiles()
    • getModifiedFiles

      public List<String> getModifiedFiles()
      Get the paths of files which have been modified by this merge.
      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()
      Get 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.
      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()
      Get the mergeResults
      Returns:
      the mergeResults
    • getFailingPaths

      public Map<String,ResolveMerger.MergeFailureReason> getFailingPaths()
      Get list of paths causing this merge to fail (not stopped because of a conflict).
      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 - a AbstractTreeIterator object.
      headTree - a RevTree object.
      mergeTree - a RevTree object.
      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 - if an IO error occurred
      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 - if an IO error occurred
      Since:
      3.5