Package org.apache.lucene.index

Class FilterLeafReader

java.lang.Object
org.apache.lucene.index.IndexReader
org.apache.lucene.index.LeafReader
org.apache.lucene.index.FilterLeafReader
All Implemented Interfaces:
Closeable, AutoCloseable
Direct Known Subclasses:
ExitableDirectoryReader.ExitableFilterAtomicReader
public abstract class FilterLeafReader extends LeafReader
A FilterLeafReader contains another LeafReader, which it uses as its basic source of data, possibly transforming the data along the way or providing additional functionality. The class FilterLeafReader itself simply implements all abstract methods of IndexReader with versions that pass all requests to the contained index reader. Subclasses of FilterLeafReader may further override some of these methods and may also provide additional methods and fields.

NOTE: If you override getLiveDocs(), you will likely need to override numDocs() as well and vice-versa.

NOTE: If this FilterLeafReader does not change the content the contained reader, you could consider delegating calls to LeafReader.getCoreCacheHelper() and IndexReader.getReaderCacheHelper().

  • Field Details

    • in

      protected final LeafReader in
      The underlying LeafReader.

  • Constructor Details

    • FilterLeafReader

      protected FilterLeafReader(LeafReader in)
      Construct a FilterLeafReader based on the specified base reader.

      Note that base reader is closed if this FilterLeafReader is closed.

      Parameters:
      in - specified base reader.

  • Method Details

    • unwrap

      public static LeafReader unwrap(LeafReader reader)
      Get the wrapped instance by reader as long as this reader is an instance of FilterLeafReader.

    • getLiveDocs

      public Bits getLiveDocs()
      Description copied from class: LeafReader
      Returns the Bits representing live (not deleted) docs. A set bit indicates the doc ID has not been deleted. If this method returns null it means there are no deleted documents (all documents are live).

      The returned instance has been safely published for use by multiple threads without additional synchronization.

      Specified by:
      getLiveDocs in class LeafReader

    • getFieldInfos

      public FieldInfos getFieldInfos()
      Description copied from class: LeafReader
      Get the FieldInfos describing all fields in this reader.

      Note: Implementations should cache the FieldInfos instance returned by this method such that subsequent calls to this method return the same instance.

      Specified by:
      getFieldInfos in class LeafReader

    • getPointValues

      public PointValues getPointValues(String field) throws IOException
      Description copied from class: LeafReader
      Returns the PointValues used for numeric or spatial searches for the given field, or null if there are no point fields.
      Specified by:
      getPointValues in class LeafReader
      Throws:
      IOException

    • getVectorValues

      public VectorValues getVectorValues(String field) throws IOException
      Description copied from class: LeafReader
      Returns VectorValues for this field, or null if no VectorValues were indexed. The returned instance should only be used by a single thread.
      Specified by:
      getVectorValues in class LeafReader
      Throws:
      IOException

    • searchNearestVectors

      public TopDocs searchNearestVectors(String field, float[] target, int k, Bits acceptDocs, int visitedLimit) throws IOException
      Description copied from class: LeafReader
      Return the k nearest neighbor documents as determined by comparison of their vector values for this field, to the given vector, by the field's similarity function. The score of each document is derived from the vector similarity in a way that ensures scores are positive and that a larger score corresponds to a higher ranking.

      The search is allowed to be approximate, meaning the results are not guaranteed to be the true k closest neighbors. For large values of k (for example when k is close to the total number of documents), the search may also retrieve fewer than k documents.

      The returned TopDocs will contain a ScoreDoc for each nearest neighbor, sorted in order of their similarity to the query vector (decreasing scores). The TotalHits contains the number of documents visited during the search. If the search stopped early because it hit visitedLimit, it is indicated through the relation TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO.

      Specified by:
      searchNearestVectors in class LeafReader
      Parameters:
      field - the vector field to search
      target - the vector-valued query
      k - the number of docs to return
      acceptDocs - Bits that represents the allowed documents to match, or null if they are all allowed to match.
      visitedLimit - the maximum number of nodes that the search is allowed to visit
      Returns:
      the k nearest neighbor documents, along with their (searchStrategy-specific) scores.
      Throws:
      IOException

    • getTermVectors

      public Fields getTermVectors(int docID) throws IOException
      Description copied from class: IndexReader
      Retrieve term vectors for this document, or null if term vectors were not indexed. The returned Fields instance acts like a single-document inverted index (the docID will be 0).
      Specified by:
      getTermVectors in class IndexReader
      Throws:
      IOException

    • numDocs

      public int numDocs()
      Description copied from class: IndexReader
      Returns the number of documents in this index.

      NOTE: This operation may run in O(maxDoc). Implementations that can't return this number in constant-time should cache it.

      Specified by:
      numDocs in class IndexReader

    • maxDoc

      public int maxDoc()
      Description copied from class: IndexReader
      Returns one greater than the largest possible document number. This may be used to, e.g., determine how big to allocate an array which will have an element for every document number in an index.
      Specified by:
      maxDoc in class IndexReader

    • document

      public void document(int docID, StoredFieldVisitor visitor) throws IOException
      Description copied from class: IndexReader
      Expert: visits the fields of a stored document, for custom processing/loading of each field. If you simply want to load all fields, use IndexReader.document(int). If you want to load a subset, use DocumentStoredFieldVisitor.
      Specified by:
      document in class IndexReader
      Throws:
      IOException

    • doClose

      protected void doClose() throws IOException
      Description copied from class: IndexReader
      Implements close.
      Specified by:
      doClose in class IndexReader
      Throws:
      IOException

    • terms

      public Terms terms(String field) throws IOException
      Description copied from class: LeafReader
      Returns the Terms index for this field, or null if it has none.
      Specified by:
      terms in class LeafReader
      Throws:
      IOException

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • getNumericDocValues

      public NumericDocValues getNumericDocValues(String field) throws IOException
      Description copied from class: LeafReader
      Returns NumericDocValues for this field, or null if no numeric doc values were indexed for this field. The returned instance should only be used by a single thread.
      Specified by:
      getNumericDocValues in class LeafReader
      Throws:
      IOException

    • getBinaryDocValues

      public BinaryDocValues getBinaryDocValues(String field) throws IOException
      Description copied from class: LeafReader
      Returns BinaryDocValues for this field, or null if no binary doc values were indexed for this field. The returned instance should only be used by a single thread.
      Specified by:
      getBinaryDocValues in class LeafReader
      Throws:
      IOException

    • getSortedDocValues

      public SortedDocValues getSortedDocValues(String field) throws IOException
      Description copied from class: LeafReader
      Returns SortedDocValues for this field, or null if no SortedDocValues were indexed for this field. The returned instance should only be used by a single thread.
      Specified by:
      getSortedDocValues in class LeafReader
      Throws:
      IOException

    • getSortedNumericDocValues

      public SortedNumericDocValues getSortedNumericDocValues(String field) throws IOException
      Description copied from class: LeafReader
      Returns SortedNumericDocValues for this field, or null if no SortedNumericDocValues were indexed for this field. The returned instance should only be used by a single thread.
      Specified by:
      getSortedNumericDocValues in class LeafReader
      Throws:
      IOException

    • getSortedSetDocValues

      public SortedSetDocValues getSortedSetDocValues(String field) throws IOException
      Description copied from class: LeafReader
      Returns SortedSetDocValues for this field, or null if no SortedSetDocValues were indexed for this field. The returned instance should only be used by a single thread.
      Specified by:
      getSortedSetDocValues in class LeafReader
      Throws:
      IOException

    • getNormValues

      public NumericDocValues getNormValues(String field) throws IOException
      Description copied from class: LeafReader
      Returns NumericDocValues representing norms for this field, or null if no NumericDocValues were indexed. The returned instance should only be used by a single thread.
      Specified by:
      getNormValues in class LeafReader
      Throws:
      IOException

    • getMetaData

      public LeafMetaData getMetaData()
      Description copied from class: LeafReader
      Return metadata about this leaf.
      Specified by:
      getMetaData in class LeafReader

    • checkIntegrity

      public void checkIntegrity() throws IOException
      Description copied from class: LeafReader
      Checks consistency of this reader.

      Note that this may be costly in terms of I/O, e.g. may involve computing a checksum value against large data files.

      Specified by:
      checkIntegrity in class LeafReader
      Throws:
      IOException

    • getDelegate

      public LeafReader getDelegate()
      Returns the wrapped LeafReader.