Package org.apache.lucene.index

Class SegmentReader

java.lang.Object
org.apache.lucene.index.IndexReader
org.apache.lucene.index.LeafReader
org.apache.lucene.index.CodecReader
org.apache.lucene.index.SegmentReader
All Implemented Interfaces:
Closeable, AutoCloseable
public final class SegmentReader extends CodecReader
IndexReader implementation over a single segment.

Instances pointing to the same segment (but with different deletes, etc) may share the same core data.

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

  • Method Details

    • 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

    • doClose

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

    • 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

    • 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

    • getTermVectorsReader

      public TermVectorsReader getTermVectorsReader()
      Description copied from class: CodecReader
      Expert: retrieve thread-private TermVectorsReader
      Specified by:
      getTermVectorsReader in class CodecReader

    • getFieldsReader

      public StoredFieldsReader getFieldsReader()
      Description copied from class: CodecReader
      Expert: retrieve thread-private StoredFieldsReader
      Specified by:
      getFieldsReader in class CodecReader

    • getPointsReader

      public PointsReader getPointsReader()
      Description copied from class: CodecReader
      Expert: retrieve underlying PointsReader
      Specified by:
      getPointsReader in class CodecReader

    • getNormsReader

      public NormsProducer getNormsReader()
      Description copied from class: CodecReader
      Expert: retrieve underlying NormsProducer
      Specified by:
      getNormsReader in class CodecReader

    • getDocValuesReader

      public DocValuesProducer getDocValuesReader()
      Description copied from class: CodecReader
      Expert: retrieve underlying DocValuesProducer
      Specified by:
      getDocValuesReader in class CodecReader

    • getVectorReader

      public KnnVectorsReader getVectorReader()
      Description copied from class: CodecReader
      Expert: retrieve underlying VectorReader
      Specified by:
      getVectorReader in class CodecReader

    • getPostingsReader

      public FieldsProducer getPostingsReader()
      Description copied from class: CodecReader
      Expert: retrieve underlying FieldsProducer
      Specified by:
      getPostingsReader in class CodecReader

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • getSegmentName

      public String getSegmentName()
      Return the name of the segment this reader is reading.

    • getSegmentInfo

      public SegmentCommitInfo getSegmentInfo()
      Return the SegmentInfoPerCommit of the segment this reader is reading.

    • directory

      public Directory directory()
      Returns the directory this index resides in.

    • notifyReaderClosedListeners

      protected void notifyReaderClosedListeners() throws IOException
      Description copied from class: IndexReader
      For test framework use only.
      Overrides:
      notifyReaderClosedListeners in class IndexReader
      Throws:
      IOException

    • getReaderCacheHelper

      public IndexReader.CacheHelper getReaderCacheHelper()
      Description copied from class: IndexReader
      Optional method: Return a IndexReader.CacheHelper that can be used to cache based on the content of this reader. Two readers that have different data or different sets of deleted documents will be considered different.

      A return value of null indicates that this reader is not suited for caching, which is typically the case for short-lived wrappers that alter the content of the wrapped reader.

      Specified by:
      getReaderCacheHelper in class IndexReader

    • getCoreCacheHelper

      public IndexReader.CacheHelper getCoreCacheHelper()
      Description copied from class: LeafReader
      Optional method: Return a IndexReader.CacheHelper that can be used to cache based on the content of this leaf regardless of deletions. Two readers that have the same data but different sets of deleted documents or doc values updates may be considered equal. Consider using IndexReader.getReaderCacheHelper() if you need deletions or dv updates to be taken into account.

      A return value of null indicates that this reader is not suited for caching, which is typically the case for short-lived wrappers that alter the content of the wrapped leaf reader.

      Specified by:
      getCoreCacheHelper in class LeafReader

    • getMetaData

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

    • getHardLiveDocs

      public Bits getHardLiveDocs()
      Returns the live docs that are not hard-deleted. This is an expert API to be used with soft-deletes to filter out document that hard deleted for instance due to aborted documents or to distinguish soft and hard deleted documents ie. a rolled back tombstone.
      WARNING: This API is experimental and might change in incompatible ways in the next release.

    • 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.

      Overrides:
      checkIntegrity in class CodecReader
      Throws:
      IOException