Interface ViewOperations

    • Method Detail

      • current

        ViewMetadata current()
        Return the currently loaded view metadata, without checking for updates.
        Returns:
        view metadata
      • refresh

        ViewMetadata refresh()
        Return the current view metadata after checking for updates.
        Returns:
        view metadata
      • commit

        void commit​(ViewMetadata base,
                    ViewMetadata metadata)
        Replace the base view metadata with a new version.

        This method should implement and document atomicity guarantees.

        Implementations must check that the base metadata is current to avoid overwriting updates. Once the atomic commit operation succeeds, implementations must not perform any operations that may fail because failure in this method cannot be distinguished from commit failure.

        Implementations should throw a CommitStateUnknownException in cases where it cannot be determined if the commit succeeded or failed. For example if a network partition causes the confirmation of the commit to be lost, the implementation should throw a CommitStateUnknownException. An unknown state indicates to downstream users of this API that it is not safe to perform clean up and remove any files. In general, strict metadata cleanup will only trigger cleanups when the commit fails with an exception implementing the marker interface CleanableFailure. All other exceptions will be treated as if the commit has failed.

        Parameters:
        base - view metadata on which changes were based
        metadata - new view metadata with updates