# All Classes

- All Classes Class Summary Enum Summary
  Class | Description
  --- | ---
  CompressionMode | A compression mode.
  Compressor | A data compressor.
  Decompressor | A decompressor.
  DeflateWithPresetDictCompressionMode | A compression mode that trades speed for compression ratio.
  EndiannessReverserUtil | Utility class to wrap open files
  FieldReader | BlockTree's implementation of `Terms`.
  ForDeltaUtil | Utility class to encode/decode increasing sequences of 128 integers.
  LegacyDirectMonotonicReader | Retrieves an instance previously written by `LegacyDirectMonotonicWriter`.
  LegacyDirectMonotonicReader.Meta | In-memory metadata that needs to be kept around for `LegacyDirectMonotonicReader` to read data from disk.
  LegacyDirectMonotonicWriter | Write monotonically-increasing sequences of integers.
  LegacyDirectReader | Retrieves an instance previously written by `LegacyDirectWriter`
  LegacyDirectWriter | Class for writing packed integers to be directly read from Directory.
  LegacyPackedInts | Legacy PackedInts operations.
  Lucene40BlockTreeTermsReader | A block-based terms index and dictionary that assigns terms to variable length blocks according to how they share prefixes.
  Lucene50CompoundFormat | Lucene 5.0 compound file format
  Lucene50CompressingStoredFieldsFormat | A `StoredFieldsFormat` that compresses documents in chunks in order to improve the compression ratio.
  Lucene50CompressingStoredFieldsReader | `StoredFieldsReader` impl for `Lucene50CompressingStoredFieldsFormat`.
  Lucene50CompressingTermVectorsFormat | A `TermVectorsFormat` that compresses chunks of documents together in order to improve the compression ratio.
  Lucene50CompressingTermVectorsReader | `TermVectorsReader` for `Lucene50CompressingTermVectorsFormat`.
  Lucene50LiveDocsFormat | Lucene 5.0 live docs format
  Lucene50PostingsFormat | Lucene 5.0 postings format, which encodes postings in packed integer blocks for fast decode.
  Lucene50PostingsFormat.IntBlockTermState | Holds all state required for `Lucene50PostingsReader` to produce a `PostingsEnum` without re-seeking the terms dict.
  Lucene50PostingsReader | Concrete class that reads docId(maybe frq,pos,offset,payloads) list with postings format.
  Lucene50StoredFieldsFormat | Lucene 5.0 stored fields format.
  Lucene50StoredFieldsFormat.Mode | Configuration option for stored fields.
  Lucene50TermVectorsFormat | Lucene 5.0 `term vectors format`.
  Lucene60FieldInfosFormat | Lucene 6.0 Field Infos format.
  Lucene60PointsFormat | Lucene 6.0 point format, which encodes dimensional values in a block KD-tree structure for fast 1D range and N dimensional shape intersection filtering.
  Lucene60PointsReader | Reads point values previously written with Lucene60PointsWriter
  Lucene70Codec | Implements the Lucene 7.0 index format, with configurable per-field postings and docvalues formats.
  Lucene70DocValuesFormat | Lucene 7.0 DocValues format.
  Lucene70NormsFormat | Lucene 7.0 Score normalization format.
  Lucene70SegmentInfoFormat | Lucene 7.0 Segment info format.
  Lucene80Codec | Implements the Lucene 8.0 index format.
  Lucene80DocValuesFormat | Lucene 8.0 DocValues format.
  Lucene80DocValuesFormat.Mode | Configuration option for doc values.
  Lucene80NormsFormat | Lucene 8.0 Score normalization format.
  Lucene84Codec | Implements the Lucene 8.4 index format, with configurable per-field postings and docvalues formats.
  Lucene84PostingsFormat | Lucene 5.0 postings format, which encodes postings in packed integer blocks for fast decode.
  Lucene84PostingsFormat.IntBlockTermState | Holds all state required for `Lucene84PostingsReader` to produce a `PostingsEnum` without re-seeking the terms dict.
  Lucene84PostingsReader | Concrete class that reads docId(maybe frq,pos,offset,payloads) list with postings format.
  Lucene86Codec | Implements the Lucene 8.6 index format, with configurable per-field postings and docvalues formats.
  Lucene86PointsFormat | Lucene 8.6 point format, which encodes dimensional values in a block KD-tree structure for fast 1D range and N dimensional shape intersection filtering.
  Lucene86PointsReader | Reads point values previously written with Lucene86PointsWriter
  Lucene86SegmentInfoFormat | Lucene 8.6 Segment info format.
  Lucene87Codec | Implements the Lucene 8.6 index format, with configurable per-field postings and docvalues formats.
  Lucene87Codec.Mode | Configuration option for the codec.
  Lucene87StoredFieldsFormat | Lucene 8.7 stored fields format.
  Lucene87StoredFieldsFormat.Mode | Configuration option for stored fields.
  Lucene90BoundsChecker | A helper class for an hnsw graph that serves as a comparator of the currently set bound value with a new value.
  Lucene90BoundsChecker.Max | A helper class for an hnsw graph that serves as a comparator of the currently set maximum value with a new value.
  Lucene90BoundsChecker.Min | A helper class for an hnsw graph that serves as a comparator of the currently set minimum value with a new value.
  Lucene90Codec | Implements the Lucene 9.0 index format
  Lucene90Codec.Mode | Configuration option for the codec.
  Lucene90FieldInfosFormat | Lucene 9.0 Field Infos format.
  Lucene90HnswGraphBuilder | Builder for HNSW graph.
  Lucene90HnswVectorsFormat | Lucene 9.0 vector format, which encodes numeric vector values and an optional associated graph connecting the documents having values.
  Lucene90HnswVectorsReader | Reads vectors from the index segments along with index data structures supporting KNN search.
  Lucene90NeighborArray | NeighborArray encodes the neighbors of a node and their mutual scores in the HNSW graph as a pair of growable arrays.
  Lucene90OnHeapHnswGraph | An `HnswGraph` where all nodes and connections are held in memory.
  Lucene90PostingsFormat | Lucene 9.0 postings format, which encodes postings in packed integer blocks for fast decode.
  Lucene90PostingsFormat.IntBlockTermState | Holds all state required for `Lucene90PostingsReader` to produce a `PostingsEnum` without re-seeking the terms dict.
  Lucene90PostingsReader | Concrete class that reads docId(maybe frq,pos,offset,payloads) list with postings format.
  Lucene90PostingsWriter | Concrete class that writes docId(maybe frq,pos,offset,payloads) list with postings format.
  Lucene90SegmentInfoFormat | Lucene 9.0 Segment info format.
  Lucene91BoundsChecker | A helper class for an hnsw graph that serves as a comparator of the currently set bound value with a new value.
  Lucene91BoundsChecker.Max | A helper class for an hnsw graph that serves as a comparator of the currently set maximum value with a new value.
  Lucene91BoundsChecker.Min | A helper class for an hnsw graph that serves as a comparator of the currently set minimum value with a new value.
  Lucene91Codec | Implements the Lucene 9.1 index format
  Lucene91Codec.Mode | Configuration option for the codec.
  Lucene91HnswVectorsFormat | Lucene 9.1 vector format, which encodes numeric vector values and an optional associated graph connecting the documents having values.
  Lucene91HnswVectorsReader | Reads vectors from the index segments along with index data structures supporting KNN search.
  Lucene91NeighborArray | NeighborArray encodes the neighbors of a node and their mutual scores in the HNSW graph as a pair of growable arrays.
  Lucene91OnHeapHnswGraph | An `HnswGraph` where all nodes and connections are held in memory.
  Lucene92Codec | Implements the Lucene 9.2 index format
  Lucene92Codec.Mode | Configuration option for the codec.
  Lucene92HnswVectorsFormat | Lucene 9.2 vector format, which encodes numeric vector values and an optional associated graph connecting the documents having values.
  Lucene92HnswVectorsReader | Reads vectors from the index segments along with index data structures supporting KNN search.
  Lucene94Codec | Implements the Lucene 9.4 index format
  Lucene94Codec.Mode | Configuration option for the codec.
  Lucene94HnswVectorsFormat | Lucene 9.4 vector format, which encodes numeric vector values and an optional associated graph connecting the documents having values.
  Lucene94HnswVectorsReader | Reads vectors from the index segments along with index data structures supporting KNN search.
  Lucene95Codec | Implements the Lucene 9.5 index format
  Lucene95Codec.Mode | Configuration option for the codec.
  Lucene95HnswVectorsFormat | Lucene 9.5 vector format, which encodes numeric vector values and an optional associated graph connecting the documents having values.
  Lucene95HnswVectorsReader | Reads vectors from the index segments along with index data structures supporting KNN search.
  LZ4WithPresetDictCompressionMode | A compression mode that compromises on the compression ratio to provide fast compression and decompression.
  MatchingReaders | Computes which segments have identical field name to number mappings, which allows stored fields and term vectors in this codec to be bulk-merged.
  PForUtil | Utility class to encode sequences of 128 small positive integers.
  Placeholder | Remove this file when adding back compat codecs
  Stats | BlockTree statistics for a single field returned by `FieldReader.getStats()`.