Interface IndexSorter

All Known Implementing Classes:
IndexSorter.DoubleSorter, IndexSorter.FloatSorter, IndexSorter.IntSorter, IndexSorter.LongSorter, IndexSorter.StringSorter

public interface IndexSorter
Handles how documents should be sorted in an index, both within a segment and between segments.

Implementers must provide the following methods: getDocComparator(LeafReader,int) - an object that determines how documents within a segment are to be sorted getComparableProviders(List) - an array of objects that return a sortable long value per document and segment getProviderName() - the SPI-registered name of a SortFieldProvider to serialize the sort

The companion SortFieldProvider should be registered with SPI via META-INF/services

  • Method Details

    • getComparableProviders

      IndexSorter.ComparableProvider[] getComparableProviders(List<? extends LeafReader> readers) throws IOException
      Get an array of IndexSorter.ComparableProvider, one per segment, for merge sorting documents in different segments
      readers - the readers to be merged
    • getDocComparator

      IndexSorter.DocComparator getDocComparator(LeafReader reader, int maxDoc) throws IOException
      Get a comparator that determines the sort order of docs within a single Reader.

      NB We cannot simply use the FieldComparator API because it requires docIDs to be sent in-order. The default implementations allocate array[maxDoc] to hold native values for comparison, but 1) they are transient (only alive while sorting this one segment) and 2) in the typical index sorting case, they are only used to sort newly flushed segments, which will be smaller than merged segments

      reader - the Reader to sort
      maxDoc - the number of documents in the Reader
    • getProviderName

      String getProviderName()
      The SPI-registered name of a SortFieldProvider that will deserialize the parent SortField