Class DelegatingStorageMerger

  • All Implemented Interfaces:
    IStorageMerger

    public class DelegatingStorageMerger
    extends Object
    implements IStorageMerger
    This storage merger delegates to the appropriate merger or returns a conflict if no merger is available or if a merge was not possible.

    The target storage is used to look for an appropriate merger. If the target is an IFile, the content type of the file is used. Otherwise, the IContentTypeManager is used to find an appropriate content type. If an appropriate merger is not found, a status containing the CONFLICT is returned.

    Clients may use this class directly or subclass it.

    Since:
    3.4
    • Constructor Detail

      • DelegatingStorageMerger

        public DelegatingStorageMerger()
        Default no-arg constructor.
    • Method Detail

      • createTextMerger

        public static IStorageMerger createTextMerger()
        Return the storage merger associated with the IContentTypeManager.CT_TEXT content type.
        Returns:
        the storage merger associated with the IContentTypeManager.CT_TEXT content type
      • getInstance

        public static IStorageMerger getInstance()
        Helper method that returns a singleton instance that can be used to merge two IStorage instances.
        Returns:
        a storage merger that delegates the merge based on the type of the target storage.
      • merge

        public IStatus merge​(OutputStream output,
                             String outputEncoding,
                             IStorage ancestor,
                             IStorage target,
                             IStorage other,
                             IProgressMonitor monitor)
                      throws CoreException
        Description copied from interface: IStorageMerger
        Performs a merge operation on the given storage instances and writes the merge result to the output stream. On success a status IStatus.OK is returned, on error a status IStatus.ERROR. If the merge operation cannot deal with conflicts, the code of the error status has the value IStreamMerger.CONFLICT. For text oriented mergers the encoding for the input and output is honored if they implement IEncodedStorage. It is the responsibility of callers to close the output stream.

        The provided ancestor may be null if this merger returns true from IStorageMerger.canMergeWithoutAncestor().

        Specified by:
        merge in interface IStorageMerger
        Parameters:
        output - the byte stream to which the merge result is written; the merger will not close the stream
        outputEncoding - the encoding to use when writing to the output stream
        ancestor - the storage from which the common ancestor is read
        target - the storage containing the target of the merge
        other - the storage containing the target of the merge
        monitor - reports progress of the merge operation
        Returns:
        returns the completion status of the operation
        Throws:
        CoreException - if an error occurs
      • getExtension

        public static String getExtension​(String name)
        Helper method for returning the extension of a file name
        Parameters:
        name - the file name
        Returns:
        the extension of the file name or null if the file name does not have an extension
      • getContentType

        public static IContentType getContentType​(IStorage target)
                                           throws CoreException
        A helper method that finds the content type for the given storage or returns null if a content type cannot be found. Any exceptions that occur when trying to determine the content type are propagated.
        Parameters:
        target - the storage that contains the target contents of the merge.
        Returns:
        the content type of the storage or null
        Throws:
        CoreException - if an exception occurs
      • canMergeWithoutAncestor

        public boolean canMergeWithoutAncestor()
        Description copied from interface: IStorageMerger
        Return whether this merger can merge the two contributors without an ancestor. This is typically not possible but may be for some file types (for instances, files that contain a timestamp based list of events).
        Specified by:
        canMergeWithoutAncestor in interface IStorageMerger
        Returns:
        whether this merger can merge the two contributors without an ancestor