Class IndexCommit

  • All Implemented Interfaces:
    Comparable<IndexCommit>
    Direct Known Subclasses:
    SnapshotDeletionPolicy.SnapshotCommitPoint

    public abstract class IndexCommit
    extends Object
    implements Comparable<IndexCommit>

    Expert: represents a single commit into an index as seen by the IndexDeletionPolicy or IndexReader.

    Changes to the content of an index are made visible only after the writer who made that change commits by writing a new segments file (segments_N). This point in time, when the action of writing of a new segments file to the directory is completed, is an index commit.

    Each index commit point has a unique segments file associated with it. The segments file associated with a later index commit point would have a larger N.

    WARNING: This API is experimental and might change in incompatible ways in the next release.
    • Constructor Detail

      • IndexCommit

        public IndexCommit()
    • Method Detail

      • getSegmentsFileName

        public abstract String getSegmentsFileName()
        Get the segments file (segments_N) associated with this commit point.
      • getDirectory

        public abstract Directory getDirectory()
        Returns the Directory for the index.
      • delete

        public abstract void delete()
        Delete this commit point. This only applies when using the commit point in the context of IndexWriter's IndexDeletionPolicy.

        Upon calling this, the writer is notified that this commit point should be deleted.

        Decision that a commit-point should be deleted is taken by the IndexDeletionPolicy in effect and therefore this should only be called by its onInit() or onCommit() methods.

      • isDeleted

        public abstract boolean isDeleted()
      • getSegmentCount

        public abstract int getSegmentCount()
        Returns number of segments referenced by this commit.
      • equals

        public boolean equals​(Object other)
        Two IndexCommits are equal if both their Directory and versions are equal.
        Overrides:
        equals in class Object
      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Object
      • getGeneration

        public abstract long getGeneration()
        Returns the generation (the _N in segments_N) for this IndexCommit
      • getTimestamp

        @Deprecated
        public long getTimestamp()
                          throws IOException
        Deprecated.
        If you need to track commit time of an index, you can store it in the commit data (see IndexWriter.commit(Map)
        Convenience method that returns the last modified time of the segments_N file corresponding to this index commit, equivalent to getDirectory().fileModified(getSegmentsFileName()).
        Throws:
        IOException