Package org.apache.lucene.index

Class MergePolicy.OneMerge

java.lang.Object
org.apache.lucene.index.MergePolicy.OneMerge
Enclosing class:
MergePolicy
public static class MergePolicy.OneMerge extends Object
OneMerge provides the information necessary to perform an individual primitive merge operation, resulting in a single new segment. The merge spec includes the subset of segments to be merged as well as whether the new segment should use the compound file format.

  • Field Details

    • estimatedMergeBytes

      public volatile long estimatedMergeBytes
      Estimated size in bytes of the merged segment.

    • segments

      public final List<SegmentCommitInfo> segments
      Segments to be merged.

    • totalDocCount

      public final int totalDocCount
      Number of documents in the merged segment.

  • Constructor Details

  • Method Details

    • getMergeReaders

      public List<AtomicReader> getMergeReaders() throws IOException
      Expert: Get the list of readers to merge. Note that this list does not necessarily match the list of segments to merge and should only be used to feed SegmentMerger to initialize a merge. When a MergePolicy.OneMerge reorders doc IDs, it must override getDocMap(org.apache.lucene.index.MergeState) too so that deletes that happened during the merge can be applied to the newly merged segment.
      Throws:
      IOException

    • setInfo

      public void setInfo(SegmentCommitInfo info)
      Expert: Sets the SegmentCommitInfo of this MergePolicy.OneMerge. Allows sub-classes to e.g. set diagnostics properties.

    • getDocMap

      public MergePolicy.DocMap getDocMap(MergeState mergeState)
      Expert: If getMergeReaders() reorders document IDs, this method must be overridden to return a mapping from the natural doc ID (the doc ID that would result from a natural merge) to the actual doc ID. This mapping is used to apply deletions that happened during the merge to the new segment.

    • checkAborted

      public void checkAborted(Directory dir) throws MergePolicy.MergeAbortedException
      Called periodically by IndexWriter while merging to see if the merge is aborted.
      Throws:
      MergePolicy.MergeAbortedException

    • setPause

      public void setPause(boolean paused)
      Set or clear whether this merge is paused paused (for example ConcurrentMergeScheduler will pause merges if too many are running).

    • getPause

      public boolean getPause()
      Returns true if this merge is paused.
      See Also:

    • segString

      public String segString(Directory dir)
      Returns a readable description of the current merge state.

    • totalBytesSize

      public long totalBytesSize() throws IOException
      Returns the total size in bytes of this merge. Note that this does not indicate the size of the merged segment, but the input total size. This is only set once the merge is initialized by IndexWriter.
      Throws:
      IOException

    • totalNumDocs

      public int totalNumDocs() throws IOException
      Returns the total number of documents that are included with this merge. Note that this does not indicate the number of documents after the merge.
      Throws:
      IOException

    • getMergeInfo

      public MergeInfo getMergeInfo()
      Return MergeInfo describing this merge.