Apache Lucene (JRuby)

C AbstractAnalysisFactory — Abstract parent class for analysis factories TokenizerFactory, TokenFilterFactory and CharFilterFactory. C AnalysisSPILoader — Helper class for loading named SPIs from classpath (e.g. C Analyzer — An Analyzer builds TokenStreams, which analyze text. C AnalyzerWrapper — Extension to Analyzer suitable for Analyzers which wrap other Analyzers. C AutomatonToTokenStream — Converts an Automaton into a TokenStream. C CachingTokenFilter — This class can be used if the token attributes of a TokenStream are intended to be consumed more than once. C CharArrayMap — A simple class that stores key Strings as char[]'s in a hash table. C CharArraySet — A simple class that stores Strings as char[]'s in a hash table. C CharFilter — Subclasses of CharFilter can be chained to filter a Reader They can be used as java.io.Reader with additional offset correction. C CharFilterFactory — Abstract parent class for analysis factories that create CharFilter instances. C CharacterBuffer — A simple IO buffer to use with CharacterUtils#fill(CharacterBuffer, Reader). C CharacterUtils — Utility class to write tokenizers or token filters. C DelegatingAnalyzerWrapper — An analyzer wrapper, that doesn't allow to wrap components or readers. C EntryIterator — public iterator class so efficient methods are exposed to users C EntrySet — public EntrySet class so efficient methods are exposed to users C FilteringTokenFilter — Abstract base class for TokenFilters that may remove tokens. C GraphTokenFilter — An abstract TokenFilter that exposes its input stream as a graph Call #incrementBaseToken() to move the root of the graph to the next position in the TokenStream, #incrementGraphToken() to move along the current graph, and #incrementGraph() to reset to the next graph based at the current root. C LowerCaseFilter — Normalizes token text to lower case. C ReuseStrategy — Strategy defining how TokenStreamComponents are reused per call to Analyzer#tokenStream(String, java.io.Reader). C StopFilter — Removes stop words from a token stream. C StopwordAnalyzerBase — Base class for Analyzers that need to make use of stopword sets. C TokenFilter — A TokenFilter is a TokenStream whose input is another TokenStream. C TokenFilterFactory — Abstract parent class for analysis factories that create org.apache.lucene.analysis.TokenFilter instances. C TokenStream — A TokenStream enumerates the sequence of tokens, either from Fields of a Document or from query text. C TokenStreamComponents — This class encapsulates the outer components of a token stream. C TokenStreamToAutomaton — Consumes a TokenStream and creates an Automaton where the transition labels are UTF8 bytes (or Unicode code points if unicodeArcs is true) from the TermToBytesRefAttribute. C Tokenizer — A Tokenizer is a TokenStream whose input is a Reader. C TokenizerFactory — Abstract parent class for analysis factories that create Tokenizer instances. C WordlistLoader — Loader for text files that represent a list of stopwords.

C StandardAnalyzer — Filters StandardTokenizer with LowerCaseFilter and StopFilter, using a configurable list of stop words. C StandardTokenizer — A grammar-based tokenizer constructed with JFlex. C StandardTokenizerFactory — Factory for StandardTokenizer. C StandardTokenizerImpl — This class implements Word Break rules from the Unicode Text Segmentation algorithm, as specified in Unicode Standard Annex #29.

I BytesTermAttribute — This attribute can be used if you have the raw term bytes to be indexed. C BytesTermAttributeImpl — Implementation class for BytesTermAttribute. I CharTermAttribute — The term text of a Token. C CharTermAttributeImpl — Default implementation of CharTermAttribute. I FlagsAttribute — This attribute can be used to pass different flags down the Tokenizer chain, e.g. C FlagsAttributeImpl — Default implementation of FlagsAttribute. I KeywordAttribute — This attribute can be used to mark a token as a keyword. C KeywordAttributeImpl — Default implementation of KeywordAttribute. I OffsetAttribute — The start and end character offset of a Token. C OffsetAttributeImpl — Default implementation of OffsetAttribute. C PackedTokenAttributeImpl — Default implementation of the common attributes used by Lucene: CharTermAttribute TypeAttribute PositionIncrementAttribute PositionLengthAttr I PayloadAttribute — The payload of a Token. C PayloadAttributeImpl — Default implementation of PayloadAttribute. I PositionIncrementAttribute — Determines the position of this token relative to the previous Token in a TokenStream, used in phrase searching. C PositionIncrementAttributeImpl — Default implementation of PositionIncrementAttribute. I PositionLengthAttribute — Determines how many positions this token spans. C PositionLengthAttributeImpl — Default implementation of PositionLengthAttribute. I SentenceAttribute — This attribute tracks what sentence a given token belongs to as well as potentially other sentence specific attributes. C SentenceAttributeImpl — Default implementation of SentenceAttribute. I TermFrequencyAttribute — Sets the custom term frequency of a term within one document. C TermFrequencyAttributeImpl — Default implementation of TermFrequencyAttribute. I TermToBytesRefAttribute — This attribute is requested by TermsHashPerField to index the contents. I TypeAttribute — A Token's lexical type. C TypeAttributeImpl — Default implementation of TypeAttribute.

C BlockTermState — Holds all state required for PostingsReaderBase to produce a org.apache.lucene.index.PostingsEnum without re-seeking the terms dict. C BufferingKnnVectorsWriter — Buffers up pending vector value(s) per doc, then flushes when segment flushes. C Codec — Encodes/decodes an inverted index segment. C CodecUtil — Utility class for reading and writing versioned headers. C CompetitiveImpactAccumulator — This class accumulates the (freq, norm) pairs that may produce competitive scores. C CompoundDirectory — A read-only Directory that consists of a view over a compound file. C CompoundFormat — Encodes/decodes compound files C DocValuesConsumer — Abstract API that consumes numeric, binary and sorted docvalues. C DocValuesFormat — Encodes/decodes per-document values. C DocValuesProducer — Abstract API that produces numeric, binary, sorted, sortedset, and sortednumeric docvalues. C FieldInfosFormat — Encodes/decodes FieldInfos C FieldsConsumer — Abstract API that consumes terms, doc, freq, prox, offset and payloads postings. C FieldsProducer — Abstract API that produces terms, doc, freq, prox, offset and payloads postings. C FilterCodec — A codec that forwards all its method calls to another codec. C Impact — Per-document scoring factors. C KnnFieldVectorsWriter — Vectors writer for a field. C KnnVectorsFormat — Encodes/decodes per-document vector and any associated indexing structures required to support nearest-neighbor search C KnnVectorsReader — Reads vectors from an index. C KnnVectorsWriter — Writes vectors to an index. C LiveDocsFormat — Format for live/deleted documents C MergedVectorValues — View over multiple vector values supporting iterator-style access via DocIdMerger. C MultiLevelSkipListReader — This abstract class reads skip lists with multiple levels. C MultiLevelSkipListWriter — This abstract class writes skip lists with multiple levels. C MutablePointTree — One leaf PointTree whose order of points can be changed. C NormsConsumer — Abstract API that consumes normalization values. C NormsFormat — Encodes/decodes per-document score normalization values. C NormsProducer — Abstract API that produces field normalization values C PointsFormat — Encodes/decodes indexed points. C PointsReader — Abstract API to visit point values. C PointsWriter — Abstract API to write points C PostingsFormat — Encodes/decodes terms, postings, and proximity data. C PostingsReaderBase — The core terms dictionaries (BlockTermsReader, BlockTreeTermsReader) interact with a single instance of this class to manage creation of org.apache.lucene.index.PostingsEnum and org.apache.lucene.index.ImpactsEnum instances. C PostingsWriterBase — Class that plugs into term dictionaries, such as Lucene103BlockTreeTermsWriter, and handles writing postings. C PushPostingsWriterBase — Extension of PostingsWriterBase, adding a push API for writing each element of the postings. C SegmentInfoFormat — Expert: Controls the format of the SegmentInfo (segment metadata file). C StoredFieldsFormat — Controls the format of stored fields C StoredFieldsReader — Codec API for reading stored fields. C StoredFieldsWriter — Codec API for writing stored fields: For every document, #startDocument() is called, informing the Codec that a new document has started. R TermStats — Holder for per-term statistics. C TermVectorsFormat — Controls the format of term vectors C TermVectorsReader — Codec API for reading term vectors: C TermVectorsWriter — Codec API for writing term vectors: For every document, #startDocument(int) is called, informing the Codec how many fields will be written.

C CompressionMode — A compression mode. C Compressor — A data compressor. C Decompressor — A decompressor. C 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.

C DefaultFlatVectorScorer — Default implementation of FlatVectorsScorer. C FlatFieldVectorsWriter — Vectors' writer for a field C FlatVectorScorerUtil — Utilities for FlatVectorsScorer. C FlatVectorsFormat — Encodes/decodes per-document vectors and provides a scoring interface for the flat stored vectors C FlatVectorsReader — Reads vectors from an index. I FlatVectorsScorer — Provides mechanisms to score vectors that are stored in a flat file The purpose of this class is for providing flexibility to the codec utilizing the v C FlatVectorsWriter — Vectors' writer for a field that allows additional indexing logic to be implemented by the caller I HnswGraphProvider — An interface that provides an HNSW graph. C ScalarQuantizedRandomVectorScorerSupplier — Quantized vector scorer supplier C ScalarQuantizedVectorScorer — Default scalar quantized implementation of FlatVectorsScorer.

C FieldReader — BlockTree's implementation of Terms. C Lucene103BlockTreeTermsReader — A block-based terms index and dictionary that assigns terms to variable length blocks according to how they share prefixes. C Lucene103BlockTreeTermsWriter — Block-based terms index and dictionary writer. C Stats — BlockTree statistics for a single field returned by FieldReader#getStats().

C ForUtil — Inspired from https://fulmicoton.com/posts/bitpacking/ Encodes multiple integers in one to get SIMD-like speedups. C IntBlockTermState — Holds all state required for Lucene104PostingsReader to produce a org.apache.lucene.index.PostingsEnum without re-seeking the terms dict. C Lucene104Codec — Implements the Lucene 10.4 index format If you want to reuse functionality of this codec in another codec, extend FilterCodec. C Lucene104HnswScalarQuantizedVectorsFormat — A vectors format that uses HNSW graph to store and search for vectors. C Lucene104PostingsFormat — Lucene 10.4 postings format, which encodes postings in packed integer blocks for fast decode. C Lucene104PostingsReader — Concrete class that reads docId(maybe frq,pos,offset,payloads) list with postings format. C Lucene104PostingsWriter — Writer for Lucene104PostingsFormat. C Lucene104ScalarQuantizedVectorScorer — Vector scorer over OptimizedScalarQuantized vectors C Lucene104ScalarQuantizedVectorsFormat — The quantization format used here is a per-vector optimized scalar quantization. C Lucene104ScalarQuantizedVectorsReader — Reader for scalar quantized vectors in the Lucene 10.4 format. C Lucene104ScalarQuantizedVectorsWriter — Writes quantized vector values and metadata to index segments in the format for Lucene 10.4. E Mode — Configuration option for the codec. C OffHeapScalarQuantizedVectorValues — Scalar quantized vector values loaded from off-heap C PostingIndexInput — Wrapper around an IndexInput and a ForUtil that optionally optimizes decoding using vectorization. C QuantizedByteVectorValues — Scalar quantized byte vector values E ScalarEncoding — Allowed encodings for scalar quantization.

C DeflateWithPresetDictCompressionMode — A compression mode that trades speed for compression ratio. C IndexedDISI — Disk-based implementation of a DocIdSetIterator which can return the index of the current document, i.e. C LZ4WithPresetDictCompressionMode — A compression mode that compromises on the compression ratio to provide fast compression and decompression. C Lucene90CompoundFormat — Lucene 9.0 compound file format Files: .cfs: An optional "virtual" file consisting of all the other index files for systems that frequently run out of file handles. C Lucene90DocValuesFormat — Lucene 9.0 DocValues format. C Lucene90LiveDocsFormat — Lucene 9.0 live docs format The .liv file is optional, and only exists when a segment contains deletions. C Lucene90NormsFormat — Lucene 9.0 Score normalization format. C Lucene90PointsFormat — Lucene 9.0 point format, which encodes dimensional values in a block KD-tree structure for fast 1D range and N dimensional shape intersection filtering. C Lucene90PointsReader — Reads point values previously written with Lucene90PointsWriter C Lucene90PointsWriter — Writes dimensional values C Lucene90StoredFieldsFormat — Lucene 9.0 stored fields format. C Lucene90TermVectorsFormat — Lucene 9.0 term vectors format. E Mode — Configuration option for stored fields.

C FieldsIndexWriter — Efficient index format for block-based Codecs. C Lucene90CompressingStoredFieldsFormat — A StoredFieldsFormat that compresses documents in chunks in order to improve the compression ratio. C Lucene90CompressingStoredFieldsReader — StoredFieldsReader impl for Lucene90CompressingStoredFieldsFormat. C Lucene90CompressingStoredFieldsWriter — StoredFieldsWriter impl for Lucene90CompressingStoredFieldsFormat. C Lucene90CompressingTermVectorsFormat — A TermVectorsFormat that compresses chunks of documents together in order to improve the compression ratio. C Lucene90CompressingTermVectorsReader — TermVectorsReader for Lucene90CompressingTermVectorsFormat. C Lucene90CompressingTermVectorsWriter — TermVectorsWriter for Lucene90CompressingTermVectorsFormat.

C Lucene94FieldInfosFormat — Lucene 9.0 Field Infos format.

C DenseOffHeapVectorValues — Dense vector values that are stored off-heap. C DenseOffHeapVectorValues — Dense vector values that are stored off-heap. I HasIndexSlice — Implementors can return the IndexInput from which their values are read. C OffHeapByteVectorValues — Read the vector values from the index input. C OffHeapFloatVectorValues — Read the vector values from the index input. C OrdToDocDISIReaderConfiguration — Configuration for DirectMonotonicReader and IndexedDISI for reading sparse vectors.

C Lucene99FlatVectorsFormat — Lucene 9.9 flat vector format, which encodes numeric vector values .vec (vector data) file For each field: Vector data ordered by field, document ordinal, and vector dimension. C Lucene99FlatVectorsReader — Reads vectors from the index segments. C Lucene99FlatVectorsWriter — Writes vector values to index segments. C Lucene99HnswVectorsFormat — Lucene 9.9 vector format, which encodes numeric vector values into an associated graph connecting the documents having values. C Lucene99HnswVectorsReader — Reads vectors from the index segments along with index data structures supporting KNN search. C Lucene99HnswVectorsWriter — Writes vector values and knn graphs to index segments. C Lucene99ScalarQuantizedVectorScorer — Optimized scalar quantized implementation of FlatVectorsScorer for quantized vectors stored in the Lucene99 format. C Lucene99SegmentInfoFormat — Lucene 9.9 Segment info format.

C FieldsReader — VectorReader that can wrap multiple delegate readers, selected by field. C PerFieldDocValuesFormat — Enables per field docvalues support. C PerFieldKnnVectorsFormat — Enables per field numeric vector support. C PerFieldPostingsFormat — Enables per field postings support.

C BinaryDocValuesField — Field that stores a per-document BytesRef value. C BinaryPoint — An indexed binary field for fast range filters. C BinaryRangeDocValues — A binary representation of a range that wraps a BinaryDocValues field C DateTools — Provides support for converting dates to strings and vice-versa. C DecodedTriangle — Represents a encoded triangle using ShapeField#decodeTriangle(byte[], DecodedTriangle). C Document — Documents are the unit of indexing and search. C DocumentStoredFieldVisitor — A StoredFieldVisitor that creates a Document from stored fields. C DoubleDocValuesField — Syntactic sugar for encoding doubles as NumericDocValues via Double#doubleToRawLongBits(double). C DoubleField — Field that stores a per-document double value for scoring, sorting or value retrieval and index the field for fast range filters. C DoublePoint — An indexed double field for fast range filters. C DoubleRange — An indexed Double Range field. C DoubleRangeDocValuesField — DocValues field for DoubleRange. C FeatureField — Field that can be used to store static scoring factors into documents. C Field — Expert: directly create a field for a document. C FieldType — Describes the properties of a field. C FloatDocValuesField — Syntactic sugar for encoding floats as NumericDocValues via Float#floatToRawIntBits(float). C FloatField — Field that stores a per-document float value for scoring, sorting or value retrieval and index the field for fast range filters. C FloatPoint — An indexed float field for fast range filters. C FloatRange — An indexed Float Range field. C FloatRangeDocValuesField — DocValues field for FloatRange. C InetAddressPoint — An indexed 128-bit InetAddress field. C InetAddressRange — An indexed InetAddress Range Field This field indexes an InetAddress range defined as a min/max pairs. C IntField — Field that stores a per-document int value for scoring, sorting or value retrieval and index the field for fast range filters. C IntPoint — An indexed int field for fast range filters. C IntRange — An indexed Integer Range field. C IntRangeDocValuesField — DocValues field for IntRange. E InvertableType — Describes how an IndexableField should be inverted for indexing terms and postings. C KeywordField — Field that indexes a per-document String or BytesRef into an inverted index for fast filtering, stores values in a columnar fashion using DocValuesType#SORTED_SET doc values for sorting and faceting, and optionally stores values as stored fields for top-hits retrieval. C KnnByteVectorField — A field that contains a single byte numeric vector (or none) for each document. C KnnFloatVectorField — A field that contains a single floating-point numeric vector (or none) for each document. C LatLonDocValuesField — An per-document location field. C LatLonPoint — An indexed location field. C LatLonShape — An geo shape utility class for indexing and searching gis geometries whose vertices are latitude, longitude values (in decimal degrees). C LatLonShapeDocValues — A concrete implementation of ShapeDocValues for storing binary doc value representation of LatLonShape geometries in a LatLonShapeDocValuesField Note: This class cannot be instantiated directly. C LatLonShapeDocValuesField — Concrete implementation of a ShapeDocValuesField for geographic geometries. C LateInteractionField — A field for storing multi-vector values for late interaction models. C LongField — Field that stores a per-document long value for scoring, sorting or value retrieval and index the field for fast range filters. C LongPoint — An indexed long field for fast range filters. C LongRange — An indexed Long Range field. C LongRangeDocValuesField — DocValues field for LongRange. C NumericDocValuesField — Field that stores a per-document long value for scoring, sorting or value retrieval. E QueryRelation — Query Relation Types * E QueryType — Used by RangeFieldQuery to check how each internal or leaf node relates to the query. C RangeFieldQuery — Query class for searching RangeField types by a defined Relation. E Resolution — Specifies the time granularity. C ShapeDocValuesField — A doc values field for LatLonShape and XYShape that uses ShapeDocValues as the underlying binary doc value format. C ShapeField — A base shape utility class used for both LatLon (spherical) and XY (cartesian) shape fields. C SortedDocValuesField — Field that stores a per-document BytesRef value, indexed for sorting. C SortedNumericDocValuesField — Field that stores a per-document long values for scoring, sorting or value retrieval. C SortedSetDocValuesField — Field that stores a set of per-document BytesRef values, indexed for faceting,grouping,joining. E Store — Specifies whether and how a field should be stored. C StoredField — A field whose value is stored so that IndexSearcher#storedFields and IndexReader#storedFields will return the field and its value. C StoredValue — Abstraction around a stored value. C StringField — A field that is indexed but not tokenized: the entire String value is indexed as a single token. E TYPE — type of triangle C TextField — A field that is indexed and tokenized, without term vectors. C Triangle — polygons are decomposed into tessellated triangles using org.apache.lucene.geo.Tessellator these triangles are encoded and inserted as separate indexed E Type — Type of a StoredValue. C XYDocValuesField — An per-document location field. C XYDocValuesPointInGeometryQuery — XYGeometry query for XYDocValuesField. C XYPointField — An indexed XY position field. C XYShape — A cartesian shape utility class for indexing and searching geometries whose vertices are unitless x, y values. C XYShapeDocValues — A concrete implementation of ShapeDocValues for storing binary doc value representation of XYShape geometries in a XYShapeDocValuesField Note: This class cannot be instantiated directly. C XYShapeDocValuesField — Concrete implementation of a ShapeDocValuesField for cartesian geometries.

C Circle — Represents a circle on the Earth's surface defined by a center point and radius. I Component2D — 2D Geometry object that supports spatial relationships with bounding boxes, triangles and points. C Component2DPredicate — A predicate that checks whether a given point is within a component2D geometry. C DistancePredicate — A predicate that checks whether a given point is within a distance of another point. C GeoEncodingUtils — reusable geopoint encoding methods C GeoUtils — Utility methods for geo-spatial calculations and coordinate validation. C Geometry — Base class for LatLonGeometry and XYGeometry C LatLonGeometry — Lat/Lon Geometry object. C Line — Represents a line on the earth's surface. I Monitor — Implementation of this interface will receive calls with internal data at each step of the triangulation algorithm. C Point — Represents a point on the earth's surface. C Polygon — Represents a closed polygon on the earth's surface. C Rectangle — Represents a rectangular bounding box on Earth's surface. E ShapeType — Enumerated type for Shapes C SimpleWKTShapeParser — Parses shape geometry represented in WKT format complies with OGC® document: 12-063r5 and ISO/IEC 13249-3:2016 standard located at http://docs.opengeo C Tessellator — Computes a triangular mesh tessellation for a given polygon. C Triangle — Triangle in the tessellated mesh E WindingOrder — used to define the orientation of 3 points -1 = Clockwise 0 = Colinear 1 = Counter-clockwise E WithinRelation — Used by withinTriangle to check the within relationship between a triangle and the query shape (e.g. C XYCircle — Represents a circle on the XY plane. C XYEncodingUtils — reusable cartesian geometry encoding methods C XYGeometry — Cartesian Geometry object. C XYLine — Represents a line in cartesian space. C XYPoint — Represents a point on the earth's surface. C XYPolygon — Represents a polygon in cartesian space. C XYRectangle — Represents a x/y cartesian rectangle.

C AutomatonTermsEnum — A FilteredTermsEnum that enumerates terms based upon what is accepted by a DFA. C BaseCompositeReader — Base class for implementing CompositeReaders based on an array of sub-readers. C BaseTermsEnum — A base TermsEnum that adds default implementations for #attributes() #termState() #seekExact(BytesRef) #seekExact(BytesRef, TermState) In s C BinaryDocValues — A per-document numeric value. C Builder — Builds a PrefixCodedTerms: call add repeatedly, then finish. C ByteVectorValues — This class provides access to per-document floating point vector values indexed as KnnByteVectorField. I CacheHelper — A utility class that gives hooks in order to help build a cache based on the data that is contained in this index. C CacheKey — A cache key identifying a resource that is being cached on. C CheckIndex — Basic tool and API to check the health of an index and write a new segments file that removes reference to problematic segments. C CheckIndexException — The marker RuntimeException used by CheckIndex APIs when index integrity failure is detected. I ClosedListener — A listener that is called when a resource gets closed. C CodecReader — LeafReader implemented by codec APIs. C CommitFailException — Thrown by TwoPhaseCommitTool#execute(TwoPhaseCommit...) when an object fails to commit(). I ComparableProvider — Used for sorting documents across segments C CompositeReader — Instances of this reader type can only be used to get stored fields from the underlying LeafReaders, but it is not possible to directly retrieve postings. C CompositeReaderContext — IndexReaderContext for CompositeReader instance. C ConcurrentMergeScheduler — A MergeScheduler that runs each merge using a separate thread. C CorruptIndexException — This exception is thrown when Lucene detects an inconsistency in the index. C DirectoryReader — DirectoryReader is an implementation of CompositeReader that can read indexes in a Directory. I DocComparator — A comparator of doc IDs, used for sorting documents within a segment C DocIDMerger — Utility class to help merging documents from sub-readers according to either simple concatenated (unsorted) order, or by a specified index-time sort, s C DocIndexIterator — A DocIdSetIterator that also provides an index() method tracking a distinct ordinal for a vector associated with each doc. I DocMap — A map of doc IDs. C DocMap — A permutation of doc IDs. C DocStats — DocStats for this index C DocValues — This class contains utility methods and constants for DocValues E DocValuesSkipIndexType — Options for skip indexes on doc values. C DocValuesSkipper — Skipper for DocValues. C DocValuesStatus — Status from testing DocValues E DocValuesType — DocValues types. C DocsWithFieldSet — Accumulator for documents that have a value for a field. C DoubleSorter — Sorts documents based on double values from a NumericDocValues instance C EmptyDocValuesProducer — Abstract base class implementing a DocValuesProducer that has no doc values. C EnumWithSlice — Holds a PostingsEnum along with the corresponding ReaderSlice. C ExitableDirectoryReader — The ExitableDirectoryReader wraps a real index DirectoryReader and allows for a QueryTimeout implementation object to be checked periodically to see if the thread should exit or not. C ExitableFilterAtomicReader — Wrapper class for another FilterAtomicReader. C ExitableSubReaderWrapper — Wrapper class for a SubReaderWrapper that is used by the ExitableDirectoryReader. C ExitableTerms — Wrapper class for another Terms implementation that is used by ExitableFields. C ExitableTermsEnum — Wrapper class for TermsEnum that is used by ExitableTerms for implementing an exitable enumeration of terms. C ExitingReaderException — Exception that is thrown to prematurely terminate a term enumeration. C FieldInfo — Access to the Field Info file that describes document fields and whether or not they are indexed. C FieldInfoStatus — Status from testing field infos. C FieldInfos — Collection of FieldInfos (accessible by number or by name). C FieldInvertState — This class tracks the number and position / offset parameters of terms being added to the index. C FieldNormStatus — Status from testing field norms. C Fields — Provides a Terms index for fields that have it, and lists which fields do. C FilterBinaryDocValues — Delegates all methods to a wrapped BinaryDocValues. C FilterCodecReader — A FilterCodecReader contains another CodecReader, which it uses as its basic source of data, possibly transforming the data along the way or providing additional functionality. C FilterDirectoryReader — A FilterDirectoryReader wraps another DirectoryReader, allowing implementations to transform or extend it. C FilterFields — Base class for filtering Fields implementations. C FilterLeafReader — 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. C FilterMergePolicy — A wrapper for MergePolicy instances. C FilterNumericDocValues — Delegates all methods to a wrapped NumericDocValues. C FilterPostingsEnum — Base class for filtering PostingsEnum implementations. C FilterSortedDocValues — Delegates all methods to a wrapped SortedDocValues. C FilterSortedNumericDocValues — Delegates all methods to a wrapped SortedNumericDocValues. C FilterSortedSetDocValues — Delegates all methods to a wrapped SortedSetDocValues. C FilterTerms — Base class for filtering Terms implementations. C FilterTermsEnum — Base class for filtering TermsEnum implementations. C FilteredTermsEnum — Abstract class for enumerating a subset of all terms. C FindSegmentsFile — Utility class for executing code that needs to do something with the current segments file. C FloatSorter — Sorts documents based on float values from a NumericDocValues instance C FloatVectorValues — This class provides access to per-document floating point vector values indexed as KnnFloatVectorField. C FreqAndNormBuffer — Wrapper around parallel arrays storing term frequencies and length normalization factors. C Impacts — Information about upcoming impacts, ie. C ImpactsEnum — Extension of PostingsEnum which also provides information about upcoming impacts. I ImpactsSource — Source of Impacts. C IndexCommit — Expert: represents a single commit into an index as seen by the IndexDeletionPolicy or IndexReader. C IndexDeletionPolicy — Expert: policy for deletion of stale index commits. C IndexFileNames — This class contains useful constants representing filenames and extensions used by lucene, as well as convenience methods for querying whether a file name matches an extension (matchesExtension), as well as generating file names from a segment name, generation and extension ( fileNameFromGeneration, segmentFileName). C IndexFormatTooNewException — This exception is thrown when Lucene detects an index that is newer than this Lucene version. C IndexFormatTooOldException — This exception is thrown when Lucene detects an index that is too old for this Lucene version C IndexNotFoundException — Signals that no index was found in the Directory. E IndexOptions — Controls how much information is stored in the postings lists. C IndexReader — IndexReader is an abstract class, providing an interface for accessing a point-in-time view of an index. C IndexReaderContext — A struct like class that represents a hierarchical relationship between IndexReader instances. I IndexReaderWarmer — If DirectoryReader#open(IndexWriter) has been called (ie, this writer is in near real-time mode), then after a merge completes, this class can be invoked to warm the reader on the newly merged segment, before the merge commits. C IndexSortStatus — Status from testing index sort I IndexSorter — Handles how documents should be sorted in an index, both within a segment and between segments. C IndexUpgrader — This is an easy-to-use tool that upgrades all segments of an index from previous Lucene versions to the current segment file format. C IndexWriter — An IndexWriter creates and maintains an index. C IndexWriterConfig — Holds all the configuration that is used to create an IndexWriter. I IndexWriterEventListener — A callback event listener for recording key events happened inside IndexWriter I IndexableField — Represents a single field for indexing. I IndexableFieldType — Describes the properties of a field. C IntSorter — Sorts documents based on integer values from a NumericDocValues instance I IntersectVisitor — We recurse the PointTree, using a provided instance of this to guide the recursion. C KeepLastNCommitsDeletionPolicy — This IndexDeletionPolicy implementation keeps the last N commits and removes all prior commits after a new commit is done. C KeepOnlyLastCommitDeletionPolicy — This IndexDeletionPolicy implementation that keeps only the most recent commit and immediately removes all prior commits after a new commit is done. C KnnVectorValues — This class abstracts addressing of document vector values indexed as KnnFloatVectorField or KnnByteVectorField. R LeafMetaData — Provides read-only metadata about a leaf. C LeafReader — LeafReader is an abstract class, providing an interface for accessing an index. C LeafReaderContext — IndexReaderContext for LeafReader instances. C Level — Class with static variables with information about CheckIndex's -level parameter. C LiveDocStatus — Status from testing livedocs C LiveIndexWriterConfig — Holds all the configuration used by IndexWriter with few setters for settings that can be changed on an IndexWriter instance "live". C LogByteSizeMergePolicy — This is a LogMergePolicy that measures size of a segment as the total byte size of the segment's files. C LogDocMergePolicy — This is a LogMergePolicy that measures size of a segment as the number of documents (not taking deletions into account). C LogMergePolicy — This class implements a MergePolicy that tries to merge segments into levels of exponentially increasing size, where each level has fewer segments than the value of the merge factor. C LongSorter — Sorts documents based on long values from a NumericDocValues instance C MappedMultiFields — A Fields implementation that merges multiple Fields into one, and maps around deleted documents. C MergeAbortedException — Thrown when a merge was explicitly aborted because IndexWriter#abortMerges was called. I MergeContext — This interface represents the current context of the merge selection process. C MergeException — Exception thrown if there are any problems while executing a merge. C MergeObserver — Observer for merge operations returned by IndexWriter#forceMergeDeletes(boolean). C MergePolicy — Expert: a MergePolicy determines the sequence of primitive merge operations. C MergeRateLimiter — This is the RateLimiter that IndexWriter assigns to each running merge, to give MergeSchedulers ionice like control. C MergeScheduler — Expert: IndexWriter uses an instance implementing this interface to execute the merges selected by a MergePolicy. I MergeSource — Provides access to new merges and executes the actual merge C MergeSpecification — A MergeSpecification instance provides the information necessary to perform multiple merges. C MergeState — Holds common state used during segment merging. E MergeTrigger — MergeTrigger is passed to MergePolicy#findMerges(MergeTrigger, SegmentInfos, MergePolicy.MergeContext) to indicate the event that triggered the merge. C MultiBits — Concatenates multiple Bits together, on every lookup. C MultiDocValues — A wrapper for CompositeIndexReader providing access to DocValues. C MultiFields — Provides a single Fields term index view over an IndexReader. C MultiLeafReader — Utility methods for working with a IndexReader as if it were a LeafReader. C MultiPostingsEnum — Exposes PostingsEnum, merged from PostingsEnum API of sub-segments. C MultiReader — A CompositeReader which reads multiple indexes, appending their content. C MultiSortedDocValues — Implements SortedDocValues over n subs, using an OrdinalMap C MultiSortedSetDocValues — Implements MultiSortedSetDocValues over n subs, using an OrdinalMap C MultiTerms — Exposes flex API, merged from flex API of sub-segments. C MultiTermsEnum — Exposes TermsEnum API, merged from TermsEnum API of sub-segments. C NoDeletionPolicy — An IndexDeletionPolicy which keeps all index commits around, never deleting them. C NoMergePolicy — A MergePolicy which never returns merges to execute. C NoMergeScheduler — A MergeScheduler which never executes any merges. C NumericDocValues — A per-document numeric value. I NumericDocValuesProvider — Provide a NumericDocValues instance for a LeafReader C OneMerge — OneMerge provides the information necessary to perform an individual primitive merge operation, resulting in a single new segment. C OneMergeProgress — Progress and state for an executing merge. C OneMergeWrappingMergePolicy — A wrapping merge policy that wraps the org.apache.lucene.index.MergePolicy.OneMerge objects returned by the wrapped merge policy. E OpenMode — Specifies the open mode for IndexWriter. C Options — Run-time configuration options for CheckIndex commands. C OrdTermState — An ordinal based TermState C OrdinalMap — Maps per-segment ordinals to/from global ordinal space, using a compact packed-ints representation. C ParallelCompositeReader — An CompositeReader which reads multiple, parallel indexes. C ParallelLeafReader — An LeafReader which reads multiple, parallel indexes. E PauseReason — Reason for pausing the merge thread. C PersistentSnapshotDeletionPolicy — A SnapshotDeletionPolicy which adds a persistence layer so that snapshots can be maintained across the life of an application. I PointTree — Basic operations to read the KD-tree. C PointValues — Access to indexed numeric values. C PointsStatus — Status from testing PointValues C PostingsEnum — Iterates through the postings. C PrefixCodedTerms — Prefix codes term instances (prefixes are shared). C PrepareCommitFailException — Thrown by TwoPhaseCommitTool#execute(TwoPhaseCommit...) when an object fails to prepareCommit(). I QueryTimeout — Query timeout abstraction that controls whether a query should continue or be stopped. C QueryTimeoutImpl — An implementation of QueryTimeout that can be used by the ExitableDirectoryReader class to time out and exit out when a query takes a long time to rewr C ReaderManager — Utility class to safely share DirectoryReader instances across multiple threads, while periodically reopening. R ReaderSlice — Subreader slice from a parent composite reader. C ReaderUtil — Common util methods for dealing with IndexReaders and IndexReaderContexts. E Relation — Used by #intersect to check how each recursive cell corresponds to the query. E SeekStatus — Represents returned result from #seekCeil. C SegmentCommitInfo — Embeds a [read-only] SegmentInfo and adds per-commit fields. C SegmentInfo — Information about a segment such as its name, directory, and files related to the segment. C SegmentInfoStatus — Holds the status of each segment in the index. C SegmentInfos — A collection of segmentInfo objects with methods for operating on those segments in relation to the file system. C SegmentOrder — Utility class to re-order segments within an IndexReader to assist in early termination. C SegmentReadState — Holder class for common parameters used during read. C SegmentReader — IndexReader implementation over a single segment. C SegmentWriteState — Holder class for common parameters used during write. C SerialMergeScheduler — A MergeScheduler that simply does each merge sequentially, using the current thread. C SimpleMergedSegmentWarmer — A very simple merged segment warmer that just ensures data structures are initialized. C SingleTermsEnum — Subclass of FilteredTermsEnum for enumerating a single term. C SlowCodecReaderWrapper — Wraps arbitrary readers for merging. C SlowImpactsEnum — ImpactsEnum that doesn't index impacts but implements the API in a legal way. C SnapshotDeletionPolicy — An IndexDeletionPolicy that wraps any other IndexDeletionPolicy and adds the ability to hold and later release snapshots of an index. C SoftDeletesDirectoryReaderWrapper — This reader filters out documents that have a doc values value in the given field and treat these documents as soft deleted. C SoftDeletesRetentionMergePolicy — This MergePolicy allows to carry over soft deleted documents across merges. C SoftDeletesStatus — Status from testing soft deletes C SortFieldProvider — Reads/Writes a named SortField from a segment info file, used to record index sorts C SortedDocValues — A per-document byte[] with presorted values. I SortedDocValuesProvider — Provide a SortedDocValues instance for a LeafReader C SortedNumericDocValues — A list of per-document numeric values, sorted according to Long#compare(long, long). C SortedSetDocValues — A multi-valued version of SortedDocValues. C Sorter — Sorts documents of a given index by returning a permutation on the document IDs. C SortingCodecReader — An org.apache.lucene.index.CodecReader which supports sorting documents by a given Sort. C SortingValuesIterator — Iterator over KnnVectorValues accepting a mapping to differently-sorted docs. C StandardDirectoryReader — Default implementation of DirectoryReader. C Status — Returned from #checkIndex() detailing the health and status of the index. E Status — Enumeration of possible return values for #needsField. R StoredFieldDataInput — A fixed size DataInput which includes the length of the input. C StoredFieldStatus — Status from testing stored fields. C StoredFieldVisitor — Expert: provides a low-level means of accessing the stored field values in an index. C StoredFields — API for reading stored fields. C StringSorter — Sorts documents based on terms from a SortedDocValues instance C Sub — Represents one sub-reader being merged C SubReaderWrapper — Factory class passed to FilterDirectoryReader constructor that allows subclasses to wrap the filtered DirectoryReader's subreaders. C Term — A Term represents a word from text. C TermIndexStatus — Status from testing term index. C TermIterator — An iterator over the list of terms stored in a PrefixCodedTerms. C TermState — Encapsulates all required internal state to position the associated TermsEnum without re-seeking. C TermStates — Maintains a IndexReader TermState view over IndexReader instances containing a single term. C TermVectorStatus — Status from testing stored fields. C TermVectors — API for reading term vectors. C Terms — Access to the terms in a specific field. C TermsEnum — Iterator to seek (#seekCeil(BytesRef), #seekExact(BytesRef)) or step through (#next terms to obtain frequency information (#docFreq), PostingsEnum or PostingsEnum for the current term (#postings. C TieredMergePolicy — Merges segments of approximately equal size, subject to an allowed number of segments per tier. I TwoPhaseCommit — An interface for implementations that support 2-phase commit. C TwoPhaseCommitTool — A utility for executing 2-phase commit on several objects. C UpgradeIndexMergePolicy — This MergePolicy is used for upgrading all existing segments of an index when calling IndexWriter#forceMerge(int). E VectorEncoding — The numeric datatype of the vector values. E VectorSimilarityFunction — Vector similarity function; used in search to return top K most similar vectors to a target vector. C VectorValuesStatus — Status from testing vector values C VerifyPointsVisitor — Walks the entire N-dimensional points space, verifying that all points fall within the last cell's boundaries.

C AbstractDocIdSetIterator — Abstract implementation of a DocIdSetIterator that tracks the current doc ID. C AbstractKnnCollector — AbstractKnnCollector is the default implementation for a knn collector used for gathering kNN results and providing topDocs from the gathered neighbors C AcceptDocs — Higher-level abstraction for document acceptance filtering. C AutomatonQuery — A Query that will match terms against a finite-state machine. C BlendedTermQuery — A Query that blends index statistics across multiple terms. R BooleanClause — A clause in a BooleanQuery. C BooleanQuery — A Query that matches documents matching boolean combinations of other queries, e.g. I BoostAttribute — Add this Attribute to a TermsEnum returned by MultiTermQuery#getTermsEnum(Terms,AttributeSource) and update the boost on each returned term. C BoostAttributeImpl — Implementation class for BoostAttribute. C BoostQuery — A Query wrapper that allows to give a boost to the wrapped query. C Builder — A builder for phrase queries. C Builder — A builder for boolean queries. C Builder — A builder for multi-phrase queries C Builder — A builder for CombinedFieldQuery. C Builder — A Builder for BlendedTermQuery. C Builder — A builder for SynonymQuery. I Bulk — Bulk scorer interface to score multiple vectors at once C BulkScorer — This class is used to score a range of documents at once, and is returned by Weight#bulkScorer. C ByteVectorSimilarityQuery — Search for all (approximate) byte vectors above a similarity threshold. C CachingCollector — Caches all docs, and optionally also scores, coming from a search, and is then able to replay them to another collector. I CheckedIntConsumer — Like IntConsumer, but may throw checked exceptions. R ChildScorable — A child Scorer and its relationship to its parent. R CollectionStatistics — Contains statistics for a collection (field). C CollectionTerminatedException — Throw this exception in LeafCollector#collect(int) to prematurely terminate collection of the current leaf. I Collector — Expert: Collectors are primarily meant to be used to gather raw results from a search, and implement sorting or custom result filtering, collation, etc. I CollectorManager — A manager of collectors. C CombinedFieldQuery — A Query that treats multiple fields as a single stream and scores terms as if they had been indexed in a single field whose values would be the union of the values of the provided fields. C ConjunctionUtils — Helper methods for building conjunction iterators C ConstantLongValuesSource — A ConstantLongValuesSource that always returns a constant value C ConstantScoreQuery — A query that wraps another query and simply returns a constant score equal to 1 for every document that matches the query. C ConstantScoreScorer — A constant-scoring Scorer. C ConstantScoreScorerSupplier — Specialization of ScorerSupplier for queries that produce constant scores. C ConstantScoreWeight — A Weight that has a constant score equal to the boost of the wrapped query. C ControlledRealTimeReopenThread — Utility class that runs a thread to manage periodicc reopens of a ReferenceManager, with methods to wait for a specific index changes to become visible. C Decorator — KnnCollector.Decorator is the base class for decorators of KnnCollector objects, which extend the object with new behaviors. C DisiPriorityQueue — A priority queue of DocIdSetIterators that orders by current doc ID. C DisiWrapper — Wrapper used in DisiPriorityQueue. C DisjunctionDISIApproximation — A DocIdSetIterator which is a disjunction of the approximations of the provided iterators. C DisjunctionMaxQuery — A query that generates the union of documents produced by its subqueries, and that scores each document with the maximum score for that document as produced by any subquery, plus a tie breaking increment for any additional matching subqueries. C DisjunctionMaxRewrite — A RewriteMethod that creates a DisjunctionMaxQuery out of the sub queries. C DocAndFloatFeatureBuffer — Wrapper around parallel arrays storing doc IDs and their corresponding features, stored as Java floats. C DocAndScoreAccBuffer — Wrapper around parallel arrays storing doc IDs and their corresponding score accumulators. C DocIdSet — A DocIdSet contains a set of doc ids. C DocIdSetBulkIterator — Bulk iterator over a DocIdSetIterator. C DocIdSetIterator — This abstract class defines methods to iterate over a set of non-decreasing doc ids. C DocIdStream — A stream of doc IDs. C DocValuesRangeIterator — Wrapper around a TwoPhaseIterator for a doc-values range query that speeds things up by taking advantage of a DocValuesSkipper. C DocValuesRewriteMethod — Rewrites MultiTermQueries into a filter, using DocValues for term enumeration. C DoubleValues — Per-segment, per-document double values, which can be calculated at search-time C DoubleValuesSource — Base class for producing DoubleValues To obtain a DoubleValues object for a leaf reader, clients should call #rewrite(IndexSearcher) against the top-level searcher, and then call #getValues(LeafReaderContext, DoubleValues) on the resulting DoubleValuesSource. C DoubleValuesSourceRescorer — A Rescorer that uses provided DoubleValuesSource to rescore first pass hits. C Entry — Extension of ScoreDoc to also store the FieldComparator slot. C ExactPhraseMatcher — Expert: Find exact phrases C Explanation — Expert: Describes the score computation for document and query. C FieldComparator — Expert: a FieldComparator compares hits so as to determine their sort order when collecting the top results with TopFieldCollector. C FieldComparatorSource — Provides a FieldComparator for custom field sorting. C FieldDoc — Expert: A ScoreDoc which also contains information about how to sort the referenced document. C FieldExistsQuery — A Query that matches documents that contain either a KnnFloatVectorField, org.apache.lucene.document.KnnByteVectorField or a field that indexes norms o C FieldValueHitQueue — Expert: A hit queue for sorting by hits by terms in more than one field. C FilterCollector — Collector delegator. C FilterDocIdSetIterator — Wrapper around a DocIdSetIterator. C FilterLeafCollector — LeafCollector delegator. C FilterMatchesIterator — A MatchesIterator that delegates all calls to another MatchesIterator C FilterScorable — Filter a Scorable, intercepting methods and optionally changing their return values The default implementation simply passes all calls to its delegate C FilterScorer — A FilterScorer contains another Scorer, which it uses as its basic source of data, possibly transforming the data along the way or providing additional functionality. C FilterWeight — A FilterWeight contains another Weight and implements all abstract methods by calling the contained weight's method. C FilteredDocIdSetIterator — Abstract decorator class of a DocIdSetIterator implementation that provides on-demand filter/validation mechanism on an underlying DocIdSetIterator. C FloatVectorSimilarityQuery — Search for all (approximate) float vectors above a similarity threshold. C FullPrecisionFloatVectorSimilarityValuesSource — A DoubleValuesSource that computes vector similarity between a query vector and raw full precision vectors indexed in provided org.apache.lucene.docume C FuzzyQuery — Implements the fuzzy search query. C FuzzyTermsEnum — Subclass of TermsEnum for enumerating all terms that are similar to the specified filter term. C FuzzyTermsException — Thrown to indicate that there was an issue creating a fuzzy query for a given term. C HitQueue — Expert: Priority queue containing hit docs C HnswQueueSaturationCollector — A KnnCollector.Decorator that early exits when nearest neighbor queue keeps saturating beyond a 'patience' parameter. C ImpactsDISI — DocIdSetIterator that skips non-competitive docs thanks to the indexed impacts. C IndexOrDocValuesQuery — A query that uses either an index structure (points or terms) or doc values in order to run a query, depending which one is more efficient. C IndexSearcher — Implements search over a single IndexReader. C IndexSortSortedNumericDocValuesRangeQuery — A range query that can take advantage of the fact that the index is sorted to speed up execution. C IndriAndQuery — A Query that matches documents matching combinations of subqueries. C IndriAndScorer — Combines scores of subscorers. C IndriAndWeight — The Weight for IndriAndQuery, used to normalize, score and explain these queries. C IndriDisjunctionScorer — The Indri implemenation of a disjunction scorer which stores the subscorers for the child queries. C IndriQuery — A Basic abstract query that all IndriQueries can extend to implement toString, equals, getClauses, and iterator. C IndriScorer — The Indri parent scorer that stores the boost so that IndriScorers can use the boost outside of the term. C KnnByteVectorQuery — Uses KnnVectorsReader#search(String, byte[], KnnCollector, AcceptDocs) to perform nearest neighbour search. I KnnCollector — KnnCollector is a knn collector used for gathering kNN results and providing topDocs from the gathered neighbors C KnnFloatVectorQuery — Uses KnnVectorsReader#search(String, float[], KnnCollector, AcceptDocs) to perform nearest neighbour search. C LRUQueryCache — A QueryCache that evicts queries using a LRU (least-recently-used) eviction policy in order to remain under a given maximum size and number of bytes used. C LateInteractionFloatValuesSource — A DoubleValuesSource that scores documents using similarity between a multi-vector query, and indexed document multi-vectors. C LateInteractionRescorer — Rescores top N results from a first pass query using a LateInteractionFloatValuesSource Typically, you run a low-cost first pass query to collect results from across the index, then use this rescorer to rerank top N hits using multi-vectors, usually from a late interaction model. I LeafCollector — Collector decouples the score from the collected doc: the score computation is skipped entirely if it's not needed. I LeafFieldComparator — Expert: comparator that gets instantiated on each leaf from a top-level FieldComparator instance. C LeafReaderContextPartition — Holds information about a specific leaf context and the corresponding range of doc ids to search within. C LeafSlice — A class holding a subset of the IndexSearchers leaf contexts to be executed within a single thread. C LiveFieldValues — Tracks live field values across NRT reader reopens. C LongValues — Per-segment, per-document long values, which can be calculated at search-time C LongValuesSource — Base class for producing LongValues To obtain a LongValues object for a leaf reader, clients should call #rewrite(IndexSearcher) against the top-level searcher, and then #getValues(LeafReaderContext, DoubleValues). C MatchAllDocsQuery — A query that matches all documents. C MatchNoDocsQuery — A query that matches no documents. I Matches — Reports the positions and optionally offsets of all matching terms in a query for a single document To obtain a MatchesIterator for a particular field, call #getMatches(String). I MatchesIterator — An iterator over match positions (and optionally offsets) for a single document and field To iterate over the matches, call #next() until it returns false, retrieving positions and/or offsets after each call. C MatchesUtils — Contains static functions that aid the implementation of Matches and MatchesIterator interfaces. I MaxNonCompetitiveBoostAttribute — Add this Attribute to a fresh AttributeSource before calling MultiTermQuery#getTermsEnum(Terms,AttributeSource). C MaxNonCompetitiveBoostAttributeImpl — Implementation class for MaxNonCompetitiveBoostAttribute. C MaxScoreCache — Compute maximum scores based on Impacts and keep them in a cache in order not to run expensive similarity score computations multiple times on the same C MultiCollector — A Collector which allows running a search with several Collectors. C MultiCollectorManager — A CollectorManager implements which wrap a set of CollectorManager as MultiCollector acts for Collector. C MultiPhraseQuery — A generalized version of PhraseQuery, with the possibility of adding more than one term at the same position that are treated as a disjunction (OR). C MultiTermQuery — An abstract Query that matches documents containing a subset of terms provided by a FilteredTermsEnum enumeration. I MultiVectorSimilarity — Interface to define the similarity function between multi-vectors C Multiset — A Multiset is a set that allows for duplicate elements. C NGramPhraseQuery — This is a PhraseQuery which is optimized for n-gram phrase query. C NamedMatches — Utility class to help extract the set of sub queries that have matched from a larger query. C NumericDocValuesRangeQuery — A Query over a range of long values E Occur — Specifies how clauses are to occur in matching documents. C PatienceKnnVectorQuery — This is a version of knn vector query that exits early when HNSW queue saturates over a #saturationThreshold for more than #patience times. C PhraseMatcher — Base class for exact and sloppy phrase matching To find matches on a document, first advance #approximation to the relevant document, then call #reset(). C PhraseQuery — A Query that matches documents containing a particular sequence of terms. C PhraseWeight — Expert: Weight class for phrase matching C PointInSetQuery — Abstract query class to find all documents whose single or multi-dimensional point values, previously indexed with e.g. C PointRangeQuery — Abstract class for range queries against single or multidimensional points such as IntPoint. C PositiveScoresOnlyCollector — A Collector implementation which wraps another Collector and makes sure only documents with scores > 0 are collected. C PostingsAndFreq — Term postings and position information for phrase matching C PrefixQuery — A Query that matches documents containing terms with a specified prefix. C Provider — A SortFieldProvider for this sort field C Provider — A SortFieldProvider for this sort C Provider — A SortFieldProvider for field sorts C PruneByAge — Simple pruner that drops any searcher older by more than the specified seconds, than the newest searcher. I Pruner — See #prune. E Pruning — Controls LeafFieldComparator how to skip documents C Query — The abstract base class for queries. I QueryCache — A cache for queries. I QueryCachingPolicy — A policy defining which filters should be cached. C QueryRescorer — A Rescorer that uses a provided Query to assign scores to the first-pass hits. C QueryVisitor — Allows recursion through a query tree C ReferenceManager — Utility class to safely share instances of a certain type across multiple threads, while periodically refreshing them. I RefreshCommitSupplier — Expert: Interface to supply commit for searcher refresh. I RefreshListener — Use to receive notification when a refresh has finished. C RegexpQuery — A fast regular expression query based on the org.apache.lucene.util.automaton package. E Relation — How the TotalHits#value should be interpreted. C RelevanceComparator — Sorts by descending relevance. C RescoreTopNQuery — A Query that re-scores another Query with a DoubleValuesSource function and cut-off the results at top N. C Rescorer — Re-scores the topN results (TopDocs) from an original query. C RewriteMethod — Abstract class that defines how the query is rewritten. C RewriteMethod — A RewriteMethod defines how queries for individual terms should be merged. C Scorable — Allows access to the score of a Query C ScoreCachingWrappingScorer — A Scorer which wraps another scorer and caches the score of the current document. C ScoreDoc — Holds one hit in TopDocs. E ScoreFunction — Defines the function to compute similarity score between query and document multi-vectors E ScoreMode — Different modes of search. C Scorer — Expert: Common scoring functionality for different types of queries. C ScorerSupplier — A supplier of Scorer. C ScoringRewrite — Base rewrite method that translates each term into a query, and keeps the scores as computed by the query. C SearcherFactory — Factory class used by SearcherManager to create new IndexSearchers. C SearcherLifetimeManager — Keeps track of current plus old IndexSearchers, closing the old ones once they have timed out. C SearcherManager — Utility class to safely share IndexSearcher instances across multiple threads, while periodically reopening. C SeededKnnVectorQuery — This is a version of knn vector query that provides a query seed to initiate the vector search. I SegmentCacheable — Interface defining whether or not an object can be cached against a LeafReader Objects that depend only on segment-immutable structures such as Points or postings lists can just return true from #isCacheable(LeafReaderContext) Objects that depend on doc values should return DocValues#isCacheable(LeafReaderContext, String...), which will check to see if the doc values fields have been updated. C SimpleCollector — Base Collector implementation that is used to collect all contexts. C SimpleFieldComparator — Base FieldComparator implementation that is used for all contexts. C SkipBlockRangeIterator — A DocIdSetIterator that returns all documents within DocValuesSkipper blocks that have minimum and maximum values that fall within a specified range. C SloppyPhraseMatcher — Find all slop-valid position-combinations (matches) encountered while traversing/hopping the PhrasePositions. C Sort — Encapsulates sort criteria for returned hits. C SortField — Stores information about how to sort documents by terms in an individual field. C SortRescorer — A Rescorer that re-sorts according to a provided Sort. C SortedNumericSelector — Selects a value from the document's list to use as the representative value This provides a NumericDocValues view over the SortedNumeric, for use with C SortedNumericSortField — SortField for SortedNumericDocValues. C SortedSetSelector — Selects a value from the document's set to use as the representative value C SortedSetSortField — SortField for SortedSetDocValues. C Stream — Iterator of encoded point values. C SynonymQuery — A query that treats multiple terms as synonyms. C TaskExecutor — Executor wrapper responsible for the execution of concurrent tasks. C TermInSetQuery — Specialization for a disjunction over many terms that, by default, behaves like a ConstantScoreQuery over a BooleanQuery containing only org.apache.lucene.search.BooleanClause.Occur#SHOULD clauses. C TermQuery — A Query that matches documents containing a term. C TermRangeQuery — A Query that matches documents within an range of terms. C TermScorer — Expert: A Scorer for documents matching a Term. R TermStatistics — Contains statistics for a specific term This class holds statistics for this term across all documents for scoring purposes: #docFreq: number of documents this term occurs in. C TermValComparator — Sorts by field's natural Term sort order. C TimeLimitingKnnCollectorManager — A KnnCollectorManager that collects results with a timeout. C TooManyClauses — Thrown when an attempt is made to add more than #getMaxClauseCount() clauses. C TooManyNestedClauses — Thrown when a client attempts to execute a Query that has more than #getMaxClauseCount() total clauses cumulatively in all of its children. C TopDocs — Represents hits returned by IndexSearcher#search(Query,int). C TopDocsCollector — A base class for all collectors that return a TopDocs output. C TopFieldCollector — A Collector that sorts by SortField using FieldComparators. C TopFieldCollectorManager — Create a TopFieldCollectorManager which uses a shared hit counter to maintain number of hits and a shared MaxScoreAccumulator to propagate the minimum score across segments if the primary sort is by relevancy. C TopFieldDocs — Represents hits returned by IndexSearcher#search(Query,int,Sort). C TopKnnCollector — TopKnnCollector is a specific KnnCollector. C TopScoreDocCollector — A Collector implementation that collects the top-scoring hits, returning them as a TopDocs. C TopScoreDocCollectorManager — Create a TopScoreDocCollectorManager which uses a shared hit counter to maintain number of hits and a shared MaxScoreAccumulator to propagate the minim C TopTermsBlendedFreqScoringRewrite — A rewrite method that first translates each term into BooleanClause.Occur#SHOULD clause in a BooleanQuery, but adjusts the frequencies used for scoring to be blended across the terms, otherwise the rarest term typically ranks highest (often not useful eg in the set of expanded terms in a FuzzyQuery). C TopTermsBoostOnlyBooleanQueryRewrite — A rewrite method that first translates each term into BooleanClause.Occur#SHOULD clause in a BooleanQuery, but the scores are only computed as the boost. C TopTermsRewrite — Base rewrite method for collecting only the top terms via a priority queue. C TopTermsScoringBooleanQueryRewrite — A rewrite method that first translates each term into BooleanClause.Occur#SHOULD clause in a BooleanQuery, and keeps the scores as computed by the query. C TotalHitCountCollector — Just counts the total number of hits. C TotalHitCountCollectorManager — Collector manager based on TotalHitCountCollector that allows users to parallelize counting the number of hits, expected to be used mostly wrapped in MultiCollectorManager. R TotalHits — Description of the total number of hits of a query. C TwoPhaseIterator — Returned by Scorer#twoPhaseIterator() to expose an approximation of a DocIdSetIterator. E Type — Type of selection to perform. E Type — Specifies the type of the terms to be sorted, or special types such as CUSTOM E Type — Type of selection to perform. C UnionFullPostingsEnum — Slower version of UnionPostingsEnum that delegates offsets and positions, for use by MatchesIterator C UnionPostingsEnum — Takes the logical union of multiple PostingsEnum iterators. C UsageTrackingQueryCachingPolicy — A QueryCachingPolicy that tracks usage statistics of recently-used filters in order to decide on which filters are worth caching. I VectorScorer — Computes the similarity score between a given query vector and different document vectors. C Weight — Expert: Calculate query weights and build query scorers. C WildcardQuery — Implements the wildcard search query.

C DocComparator — Comparator that sorts by asc _doc C DoubleComparator — Comparator based on Double#compare for numHits. C DoubleLeafComparator — Leaf comparator for DoubleComparator that provides skipping functionality C FloatComparator — Comparator based on Float#compare for numHits. C FloatLeafComparator — Leaf comparator for FloatComparator that provides skipping functionality C IntComparator — Comparator based on Integer#compare for numHits. C IntLeafComparator — Leaf comparator for IntComparator that provides skipping functionality C LongComparator — Comparator based on Long#compare for numHits. C LongLeafComparator — Leaf comparator for LongComparator that provides skipping functionality C NumericComparator — Abstract numeric comparator for comparing numeric values. C NumericLeafComparator — Leaf comparator for NumericComparator that provides skipping functionality C TermOrdValComparator — Sorts by field's natural Term sort order, using ordinals.

C Hnsw — A strategy for kNN search that uses HNSW I KnnCollectorManager — KnnCollectorManager responsible for creating KnnCollector instances. C KnnSearchStrategy — KnnSearchStrategy is a strategy for kNN search, providing additional search strategy configuration C MultiLeafKnnCollector — MultiLeafKnnCollector is a specific KnnCollector that can exchange the top collected results across segments through a shared global queue. C Patience — A strategy for kNN search on HNSW that early exits when nearest neighbor collection rate saturates. C Seeded — A strategy for kNN search that uses a set of entry points to start the search C TopKnnCollectorManager — TopKnnCollectorManager responsible for creating TopKnnCollector instances.

C AfterEffect — This class acts as the base class for the implementations of the first normalization of the informative content in the DFR framework. C AfterEffectB — Model of the information gain based on the ratio of two Bernoulli processes. C AfterEffectL — Model of the information gain based on Laplace's law of succession. C Axiomatic — Axiomatic approaches for IR. C AxiomaticF1EXP — F1EXP is defined as Sum(tf(term_doc_freq)*ln(docLen)*IDF(term)) where IDF(t) = pow((N+1)/df(t), k) N=total num of docs, df=doc freq C AxiomaticF1LOG — F1LOG is defined as Sum(tf(term_doc_freq)*ln(docLen)*IDF(term)) where IDF(t) = ln((N+1)/df(t)) N=total num of docs, df=doc freq C AxiomaticF2EXP — F2EXP is defined as Sum(tfln(term_doc_freq, docLen)*IDF(term)) where IDF(t) = pow((N+1)/df(t), k) N=total num of docs, df=doc freq C AxiomaticF2LOG — F2EXP is defined as Sum(tfln(term_doc_freq, docLen)*IDF(term)) where IDF(t) = ln((N+1)/df(t)) N=total num of docs, df=doc freq C AxiomaticF3EXP — F3EXP is defined as Sum(tf(term_doc_freq)*IDF(term)-gamma(docLen, queryLen)) where IDF(t) = pow((N+1)/df(t), k) N=total num of docs, df=doc freq gamma( C AxiomaticF3LOG — F3EXP is defined as Sum(tf(term_doc_freq)*IDF(term)-gamma(docLen, queryLen)) where IDF(t) = ln((N+1)/df(t)) N=total num of docs, df=doc freq gamma(docL C BM25Similarity — BM25 Similarity. C BasicModel — This class acts as the base class for the specific basic model implementations in the DFR framework. C BasicModelG — Geometric as limiting form of the Bose-Einstein model. C BasicModelIF — An approximation of the I(ne) model. C BasicModelIn — The basic tf-idf model of randomness. C BasicModelIne — Tf-idf model of randomness, based on a mixture of Poisson and inverse document frequency. C BasicStats — Stores all statistics commonly used ranking methods. C BooleanSimilarity — Simple similarity that gives terms a score that is equal to their query boost. I BulkSimScorer — Specialization of SimScorer for bulk-computation of scores. C ClassicSimilarity — Expert: Historical scoring implementation. I CollectionModel — A strategy for computing the collection language model. C DFISimilarity — Implements the Divergence from Independence (DFI) model based on Chi-square statistics (i.e., standardized Chi-squared distance from independence in term frequency tf). C DFRSimilarity — Implements the divergence from randomness (DFR) framework introduced in Gianni Amati and Cornelis Joost Van Rijsbergen. C DefaultCollectionModel — Models p(w|C) as the number of occurrences of the term in the collection, divided by the total number of tokens + 1. C Distribution — The probabilistic distribution used to model term occurrence in information-based models. C DistributionLL — Log-logistic distribution. C DistributionSPL — The smoothed power-law (SPL) distribution for the information-based framework that is described in the original paper. C IBSimilarity — Provides a framework for the family of information-based models, as described in Stéphane Clinchant and Eric Gaussier. C Independence — Computes the measure of divergence from independence for DFI scoring functions. C IndependenceChiSquared — Normalized chi-squared measure of distance from independence Described as: "can be used for tasks that require high precision, against both short and C IndependenceSaturated — Saturated measure of distance from independence Described as: "for tasks that require high recall against long queries" C IndependenceStandardized — Standardized measure of distance from independence Described as: "good at tasks that require high recall and high precision, especially against short C IndriCollectionModel — Models p(w|C) as the number of occurrences of the term in the collection, divided by the total number of tokens + 1. C IndriDirichletSimilarity — Bayesian smoothing using Dirichlet priors as implemented in the Indri Search engine (http://www.lemurproject.org/indri.php). C LMDirichletSimilarity — Bayesian smoothing using Dirichlet priors. C LMJelinekMercerSimilarity — Language model based on the Jelinek-Mercer smoothing method. C LMSimilarity — Abstract superclass for language modeling Similarities. C LMStats — Stores the collection distribution of the current term. C Lambda — The lambda (λw) parameter in information-based models. C LambdaDF — Computes lambda as docFreq+1 / numberOfDocuments+1. C LambdaTTF — Computes lambda as totalTermFreq+1 / numberOfDocuments+1. C MultiSimilarity — Implements the CombSUM method for combining evidence from multiple similarity values described in: Joseph A. C NoNormalization — Implementation used when there is no normalization. C Normalization — This class acts as the base class for the implementations of the term frequency normalization methods in the DFR framework. C NormalizationH1 — Normalization model that assumes a uniform distribution of the term frequency. C NormalizationH2 — Normalization model in which the term frequency is inversely related to the length. C NormalizationH3 — Dirichlet Priors normalization C NormalizationZ — Pareto-Zipf Normalization C PerFieldSimilarityWrapper — Provides the ability to use a different Similarity for different fields. C RawTFSimilarity — Similarity that returns the raw TF as score. C SimScorer — Stores the weight for a query across the indexed collection. C Similarity — Similarity defines the components of Lucene scoring. C SimilarityBase — A subclass of Similarity that provides a simplified API for its descendants. C TFIDFSimilarity — Implementation of Similarity with the Vector Space Model.

C AlreadyClosedException — This exception is thrown when there is an attempt to access something that has already been closed. C BaseDirectory — Base implementation for a concrete Directory that uses a LockFactory for locking. C BufferedChecksum — Wraps another Checksum with an internal buffer to speed up checksum calculations. C BufferedChecksumIndexInput — Simple implementation of ChecksumIndexInput that wraps another input and delegates calls. C BufferedIndexInput — Base implementation class for buffered IndexInput. C ByteArrayDataInput — DataInput backed by a byte array. C ByteArrayDataOutput — DataOutput backed by a byte array. C ByteBufferRecycler — An implementation of a ByteBuffer allocation and recycling policy. C ByteBuffersDataInput — A DataInput implementing RandomAccessInput and reading data from a list of ByteBuffers. C ByteBuffersDataOutput — A DataOutput storing data in a list of ByteBuffers. C ByteBuffersDirectory — A ByteBuffer-based Directory implementation that can be used to store index files on the heap. C ByteBuffersIndexInput — An IndexInput implementing RandomAccessInput and backed by a ByteBuffersDataInput. C ByteBuffersIndexOutput — An IndexOutput writing to a ByteBuffersDataOutput. C ChecksumIndexInput — Extension of IndexInput, computing checksum as it goes. E Context — Context is an enumerator which specifies the context in which the Directory is being used. E DataAccessHint — Hint on the data access pattern likely to be used C DataInput — Abstract base class for performing read operations of Lucene's low-level data types. C DataOutput — Abstract base class for performing write operations of Lucene's low-level data types. C Directory — A Directory provides an abstraction layer for storing a list of files. C FSDirectory — Base class for Directory implementations that store index files in the file system. C FSLockFactory — Base class for file system based locking implementation. E FileDataHint — Hints on the type of data stored in the file I FileOpenHint — Implemented by classes that can specify hints on how the file will be used C FileSwitchDirectory — Expert: A Directory instance that switches files between two other Directory instances. E FileTypeHint — Hints on the type of file being opened. C FilterDirectory — Directory implementation that delegates calls to another directory. C FilterIndexInput — IndexInput implementation that delegates calls to another directory. C FilterIndexOutput — IndexOutput implementation that delegates calls to another directory. R FlushInfo — A FlushInfo provides information required for a FLUSH context. I IOContext — IOContext holds additional details on the merge/search context. C IndexInput — Abstract base class for input from a file in a Directory. C IndexOutput — A DataOutput for appending data to a file in a Directory. C InputStreamDataInput — A DataInput wrapping a plain InputStream. C Lock — An interprocess mutex lock. C LockFactory — Base class for Locking implementation. C LockObtainFailedException — This exception is thrown when the write.lock could not be acquired. C LockReleaseFailedException — This exception is thrown when the write.lock could not be released. C LockStressTest — Simple standalone tool that forever acquires and releases a lock using a specific LockFactory. C LockValidatingDirectoryWrapper — This class makes a best-effort check that a provided Lock is valid before any destructive filesystem operation. C LockVerifyServer — Simple standalone server that must be running when you use VerifyingLockFactory. C MMapDirectory — File-based Directory implementation that uses mmap for reading, and FSDirectory.FSIndexOutput for writing. R MergeInfo — A MergeInfo provides information required for a MERGE context. C NIOFSDirectory — An FSDirectory implementation that uses java.nio's FileChannel's positional read, which allows multiple threads to read from the same file without synchronizing. C NRTCachingDirectory — Wraps a RAM-resident directory around any provided delegate directory, to be used during NRT search. C NativeFSLockFactory — Implements LockFactory using native OS file locks. C NoLockFactory — Use this LockFactory to disable locking entirely. C OutputStreamDataOutput — A DataOutput wrapping a plain OutputStream. C OutputStreamIndexOutput — Implementation class for buffered IndexOutput that writes to an OutputStream. E PreloadHint — A hint that the file should be preloaded into memory I RandomAccessInput — Random Access Index API. C RateLimitedIndexOutput — A rate limiting IndexOutput C RateLimiter — Abstract base class to rate limit IO. E ReadAdvice — Advice regarding the read access pattern. E ReadOnceHint — A IOContext.FileOpenHint indicating the file will only be read once, sequentially C SimpleFSLockFactory — Implements LockFactory using Files#createFile. C SimpleRateLimiter — Simple class to rate limit IO. C SingleInstanceLockFactory — Implements LockFactory for a single in-process instance, meaning all locking will take place through this one instance. C SleepingLockWrapper — Directory that wraps another, and that sleeps and retries if obtaining the lock fails. C TrackingDirectoryWrapper — A delegating Directory that records which files were written to and deleted. C VerifyingLockFactory — A LockFactory that wraps another LockFactory and verifies that each lock obtain/release is "correct" (never results in two processes holding the lock at the same time).

I Accountable — An object whose RAM usage can be computed. C Accountables — Helper methods for constructing nested resource descriptions and debugging RAM usage. C Allocator — Abstract class for allocating and freeing byte blocks. C Allocator — Abstract class for allocating and freeing int blocks. C AlreadySetException — Thrown when SetOnce#set(Object) is called more than once. C ArrayUtil — Methods for manipulating arrays. I Attribute — Base interface for attributes. C AttributeFactory — An AttributeFactory creates instances of AttributeImpls. C AttributeImpl — Base class for Attributes that can be added to a org.apache.lucene.util.AttributeSource. I AttributeReflector — This interface is used to reflect contents of AttributeSource or AttributeImpl. C AttributeSource — An AttributeSource contains a list of different AttributeImpls, and methods to add and get them. C BitDocIdSet — Implementation of the DocIdSet interface on top of a BitSet. C BitSet — Base implementation for a bit set. C BitSetIterator — A DocIdSetIterator which iterates over set bits in a bit set. C BitUtil — A variety of high efficiency bit twiddling routines and encoders for primitives. I Bits — Interface for Bitset-like structures. C BufferSize — A bit more descriptive unit for constructors. C Builder — Builder for creating DenseLiveDocs instances with optional pre-computed deleted count. C Builder — Builder for creating SparseLiveDocs instances with optional pre-computed deleted count. C Builder — A builder of RoaringDocIdSets. I BulkAdder — Utility class to efficiently add many docs in one go. I ByteArrayComparator — Comparator for a fixed number of bytes. C ByteBlockPool — This class enables the allocation of fixed-size buffers and their management as part of a buffer array. C ByteSequencesReader — Utility class to read length-prefixed byte[] entries from an input. C ByteSequencesWriter — Utility class to emit length-prefixed byte[] entries to an output stream for sorting. C BytesRef — Represents byte[], as a slice (offset + length) into an existing byte[]. C BytesRefArray — A simple append only random-access BytesRef array that stores full copies of the appended bytes in a ByteBlockPool. C BytesRefBlockPool — Represents a logical list of ByteRef backed by a ByteBlockPool. C BytesRefBuilder — A builder for BytesRef instances. C BytesRefComparator — Specialized BytesRef comparator that StringSorter has optimizations for. C BytesRefHash — BytesRefHash is a special purpose hash-map like data-structure optimized for BytesRef instances. I BytesRefIterator — A simple iterator interface for BytesRef iteration. C BytesStartArray — Manages allocation of the per-term addresses. C CharsRef — Represents char[], as a slice (offset + length) into an existing char[]. C CharsRefBuilder — A builder for CharsRef instances. I ClassLoaderUtils — Helper class used by ServiceLoader to investigate parent/child relationships of ClassLoaders. C ClasspathResourceLoader — Simple ResourceLoader that uses ClassLoader#getResourceAsStream(String) and Class#forName(String,boolean,ClassLoader) to open resources and classes, respectively. C CloseableThreadLocal — Java's builtin ThreadLocal has a serious flaw: it can take an arbitrarily long amount of time to dereference the things you had stored in it, even once the ThreadLocal instance itself is no longer referenced. C CollectionUtil — Methods for manipulating (sorting) and creating collections. C CommandLineUtil — Class containing some useful methods used by command line tools C Constants — Some useful constants. C Counter — Simple counter class C DenseLiveDocs — LiveDocs implementation optimized for dense deletions. C DirectAllocator — A simple Allocator that never recycles. C DirectAllocator — A simple Allocator that never recycles. C DirectBytesStartArray — A simple BytesStartArray that tracks memory allocation using a private Counter instance. C DirectTrackingAllocator — A simple Allocator that never recycles, but tracks how much total RAM is in use. C DocBaseBitSetIterator — A DocIdSetIterator like BitSetIterator but has a doc base in order to avoid storing previous 0s. C DocIdSetBuilder — A builder of DocIdSets. C FileDeleter — This class provides ability to track the reference counts of a set of index files and delete them when their counts decreased to 0. C FilterIterator — An Iterator implementation that filters elements with a boolean predicate. C FixedBitSet — BitSet of fixed length (numBits), backed by accessible (#getBits) long[], accessed with an int index, implementing Bits and DocIdSet. C FixedLengthBytesRefArray — Just like BytesRefArray except all values have the same length. I FloatToFloatFunction — Simple interface to map one float to another (useful in scaling scores). C FrequencyTrackingRingBuffer — A ring buffer that tracks the frequency of the integers that it contains. C GroupVIntUtil — This class contains utility methods and constants for group varint I IOBooleanSupplier — Boolean supplier that is allowed to throw an IOException. I IOConsumer — An IO operation with a single input that may throw an IOException. I IOFunction — A Function that may throw an IOException I IORunnable — A Runnable that may throw an IOException I IOSupplier — This is a result supplier that is allowed to throw an IOException. C IOUtils — Utilities for dealing with Closeables. A IgnoreRandomChains — Annotation to not test a class or constructor with TestRandomChains integration test. C InPlaceMergeSorter — Sorter implementation based on the merge-sort algorithm that merges in place (no extra memory will be allocated). I IndexedBytesRefIterator — An extension of BytesRefIterator that allows retrieving the index of the current element C InfoStream — Debugging API for Lucene classes such as IndexWriter and SegmentInfos. C IntBlockPool — A pool for int blocks similar to ByteBlockPool I IntReader — Provides an abstraction for read int values, so that decoding logic can be reused in different DataInput. C IntroSelector — Adaptive selection algorithm based on the introspective quick select algorithm. C IntroSorter — Sorter implementation based on a variant of the quicksort algorithm called introsort: when the recursion level exceeds the log of the length of the array to sort, it falls back to heapsort. C IntsRef — Represents int[], as a slice (offset + length) into an existing int[]. C IntsRefBuilder — A builder for IntsRef instances. C JavaLoggingInfoStream — InfoStream implementation that logs every message using Java Utils Logging (JUL) with the supplied log level. C LSBRadixSorter — A LSB Radix sorter for unsigned int values. I LiveDocs — Extension of Bits that provides efficient iteration over deleted documents. C LongBitSet — BitSet of fixed length (numBits), backed by accessible (#getBits) long[], accessed with a long index. C LongHeap — A min heap that stores longs; a primitive priority queue that like all priority queues maintains a partial ordering of its elements such that the least element can always be found in constant time. C LongValues — Abstraction over an array of longs. C LongsRef — Represents long[], as a slice (offset + length) into an existing long[]. C MSBRadixSorter — Radix sorter for variable-length strings. C MapOfSets — Helper class for keeping Lists of Objects associated with keys. C MatchAllBits — Bits impl of the specified length with all bits set. C MatchNoBits — Bits impl of the specified length with no bits set. C MathUtil — Math static utility methods. C MaxBytesLengthExceededException — Thrown if a BytesRef exceeds the BytesRefHash limit of ByteBlockPool#BYTE_BLOCK_SIZE-2. C MergedIterator — Provides a merged sorted view from several sorted iterators. C ModuleResourceLoader — Simple ResourceLoader that uses Module#getResourceAsStream(String) and Class#forName(Module,String) to open resources and classes, respectively. E MsgType — Types of messages this file deleter will broadcast REF: messages about reference FILE: messages about file I NamedSPI — Interface to support NamedSPILoader#lookup(String) by name. C NamedSPILoader — Helper class for loading named SPIs from classpath (e.g. C NamedThreadFactory — A default ThreadFactory implementation that accepts the name prefix of the created threads as a constructor argument. C NotDocIdSet — This DocIdSet encodes the negation of another DocIdSet. C NumericUtils — Helper APIs to encode numeric values as sortable bytes and vice-versa. C OfflineSorter — On-disk sorting of byte arrays. C PagedBytes — Represents a logical byte[] as a series of pages. C PagedBytesDataInput — Input that transparently iterates over pages C PagedBytesDataOutput — Output that transparently spills to new pages as necessary C PrintStreamInfoStream — InfoStream implementation over a PrintStream such as System.out. C PriorityQueue — A priority queue maintains a partial ordering of its elements such that the least element can always be found in constant time. C QueryBuilder — Creates queries from the Analyzer chain. C RadixSelector — Radix selector. C RamUsageEstimator — Estimates the size (memory representation) of Java objects. C Reader — Provides methods to read BytesRefs from a frozen PagedBytes. C RecyclingByteBlockAllocator — A ByteBlockPool.Allocator implementation that recycles unused byte blocks in a buffer and reuses them in subsequent calls to #getByteBlock(). C RecyclingIntBlockAllocator — A Allocator implementation that recycles unused int blocks in a buffer and reuses them in subsequent calls to #getIntBlock(). C RefCount — Tracks the reference count for a single index file: C RefCount — Manages reference counting for a given object. I Resettable — Implement to reset an instance I ResourceLoader — Abstraction for loading resources (streams, files, and classes). I ResourceLoaderAware — Interface for a component that needs to be initialized by an implementation of ResourceLoader. C RoaringDocIdSet — DocIdSet implementation inspired from http://roaringbitmap.org/ The space is divided into blocks of 2^16 bits and each block is encoded independently. C RollingBuffer — Acts like forever growing T[], but internally uses a circular buffer to reuse instances of T. C SameThreadExecutorService — An ExecutorService that executes tasks immediately in the calling thread during submit. C Selector — An implementation of a selection algorithm, ie. C SentinelIntSet — A native int hash-based set where one value is reserved to mean "EMPTY" internally. C SetOnce — A convenient class which offers a semi-immutable object wrapper implementation which allows one to set the value of an object exactly once, and retrieve it many times. C SloppyMath — Math functions that trade off accuracy for speed. C SmallFloat — Floating point numbers smaller than 32 bits. C SortInfo — Sort info (debugging mostly). C SortState — Used to iterate the elements of an array in a given order. C Sorter — Base class for sorting algorithms implementations. C SparseFixedBitSet — A bit set that only stores longs that have at least one bit which is set. C SparseLiveDocs — LiveDocs implementation optimized for sparse deletions. C StableMSBRadixSorter — Stable radix sorter for variable-length strings. C State — This class holds the state of an AttributeSource. C StaticImplementationAttributeFactory — Expert: AttributeFactory returning an instance of the given clazz for the attributes it implements. C StringHelper — Methods for manipulating strings. C StringSorter — A BytesRef sorter tries to use a efficient radix sorter if StringSorter#cmp is a BytesRefComparator, otherwise fallback to StringSorter#fallbackSorter A SuppressForbidden — Annotation to suppress forbidden-apis errors inside a whole class, a method, or a field. R TermAndBoost — Wraps a term and boost R TermAndVector — Word2Vec unit composed by a term with the associated vector C TernaryLongHeap — A ternary min heap that stores longs; a primitive priority queue that like all priority queues maintains a partial ordering of its elements such that the least element can always be found in constant time. C ThreadInterruptedException — Thrown by lucene on detecting that Thread.interrupt() had been called. C TimSorter — Sorter implementation based on the TimSort algorithm. C ToStringUtils — Helper methods to ease implementing Object#toString(). C UTF8CodePoint — Holds a codepoint along with the number of bytes required to represent it in UTF8 C UnicodeUtil — Class to encode java's UTF16 char[] into UTF8 byte[] without always allocating a new byte[] as String.getBytes(StandardCharsets.UTF_8) does. I Unwrappable — An object with this interface is a wrapper around another object (e.g., a filter with a delegate). C VectorUtil — Utilities for computations with numeric arrays, especially algebraic operations like vector dot products. C Version — Use by certain classes to match version compatibility across releases of Lucene. C VirtualMethod — A utility for keeping backwards compatibility on previously abstract methods (or similar replacements). C WeakIdentityMap — Implements a combination of java.util.WeakHashMap and java.util.IdentityHashMap.

E AUTOMATON_TYPE — Automata are compiled into different internal forms for the most efficient execution depending upon the language they accept. C Automata — Construction of basic automata. C Automaton — Represents an automaton and all its states and transitions. I AutomatonProvider — Automaton provider for RegExp. C Builder — Records new states and transitions and then #finish creates the Automaton. C ByteRunAutomaton — Automaton representation for matching UTF-8 byte[]. I ByteRunnable — A runnable automaton accepting byte array as input C CharacterRunAutomaton — Automaton representation for matching char[]. C CompiledAutomaton — Immutable class holding compiled details for a given Automaton. C FiniteStringsIterator — Iterates all accepted strings. E Kind — The type of expression represented by a RegExp node. C LevenshteinAutomata — Class to construct DFAs that match a word within some edit distance. C LimitedFiniteStringsIterator — FiniteStringsIterator which limits the number of iterated accepted strings. C NFARunAutomaton — A RunAutomaton that does not require DFA. C Operations — Automata operations. C RegExp — Regular Expression extension to Automaton. C RunAutomaton — Finite-state automaton with fast run operation. C StatePair — Pair of states. C TooComplexToDeterminizeException — This exception is thrown when determinizing an automaton would require too much work. C Transition — Holds one transition from an Automaton. I TransitionAccessor — Interface accessing the transitions of an automaton C UTF32ToUTF8 — Converts UTF-32 automata to the equivalent UTF-8 representation.

R BKDConfig — Basic parameters for indexing points on the BKD tree. C BKDRadixSelector — Offline Radix selector for BKD tree. C BKDReader — Handles reading a block KD-tree in byte[] space previously written with BKDWriter. C BKDWriter — Recursively builds a block KD-tree to assign all incoming points in N-dim space to smaller and smaller N-dim rectangles (cells) until the number of points in a given rectangle is <= config.maxPointsInLeafNode(). C HeapPointReader — Utility class to read buffered points from in-heap arrays. C HeapPointWriter — Utility class to write new points into in-heap arrays. C MutablePointTreeReaderUtils — Utility APIs for sorting and partitioning buffered points. C OfflinePointReader — Reads points from disk in a fixed-with format, previously written with OfflinePointWriter. C OfflinePointWriter — Writes points to disk in a fixed-with format. R PathSlice — Sliced reference to points in an PointWriter. I PointReader — One pass iterator through all points previously written with a PointWriter, abstracting away whether points are read from (offline) disk or simple arra I PointValue — Represents a dimensional point value written in the BKD tree. I PointWriter — Appends many points, and then at the end provides a PointReader to iterate those points.

C FastCompressionHashTable — Simple lossy HashTable that only stores the last ocurrence for each hash on 2^14 bytes of memory. C HighCompressionHashTable — A higher-precision HashTable. C LZ4 — LZ4 compression and decompression routines. C LowercaseAsciiCompression — Utility class that can efficiently compress arrays that mostly contain characters in the [0x1F,0x3F) or [0x5F,0x7F) ranges, which notably include all d

C Arc — Represents a single arc. C Builder — Fluent-style constructor for FST FSTCompiler. C ByteSequenceOutputs — An FST Outputs implementation where each output is a sequence of bytes. C BytesReader — Reads bytes stored in an FST. C BytesRefFSTEnum — Enumerates all input (BytesRef) + output pairs in an FST. C CharSequenceOutputs — An FST Outputs implementation where each output is a sequence of characters. C FST — Represents an finite state machine (FST), using a compact byte[] format. C FSTCompiler — Builds a minimal FST (maps an IntsRef term to an arbitrary output) from pre-sorted terms with outputs. C FSTMetadata — Represents the FST metadata. C FSTPath — Represents a path in TopNSearcher. I FSTReader — Abstraction for reading bytes necessary for FST. E INPUT_TYPE — Specifies allowed range of each int input label for this FST. C InputOutput — Holds a single input (IntsRef) + output pair. C InputOutput — Holds a single input (BytesRef) + output pair. C IntSequenceOutputs — An FST Outputs implementation where each output is a sequence of ints. C IntsRefFSTEnum — Enumerates all input (IntsRef) + output pairs in an FST. C NoOutputs — A null FST Outputs implementation; use this if you just want to build an FSA. C OffHeapFSTStore — Provides off heap storage of finite state machine (FST), using underlying index input instead of byte store on heap C OnHeapFSTStore — Provides storage of finite state machine (FST), using byte array or byte store allocated on heap. C Outputs — Represents the outputs for an FST, providing the basic algebra required for building and traversing the FST. C Pair — Holds a single pair of two outputs. C PairOutputs — An FST Outputs implementation, holding two other outputs. C PositiveIntOutputs — An FST Outputs implementation where each output is a non-negative long value. R Result — Holds a single input (IntsRef) + output, returned by shortestPaths(). C TopNSearcher — Utility class to find top N shortest paths from start point(s). C TopResults — Holds the results for a top N search using TopNSearcher C Util — Static helper methods.

C GraphTokenStreamFiniteStrings — Consumes a TokenStream and creates an Automaton where the transition labels are terms from the TermToBytesRefAttribute.

C AbstractRandomVectorScorer — Creates a default scorer for random access vectors. C AbstractUpdateableRandomVectorScorer — Creates a default scorer for random access vectors. C ArrayNodesIterator — NodesIterator that accepts nodes as an integer array. C BlockingFloatHeap — A blocking bounded min heap that stores floats. I CloseableRandomVectorScorerSupplier — A supplier that creates UpdateableRandomVectorScorer from an ordinal. C CollectionNodesIterator — Nodes iterator based on set representation of nodes. C ConcurrentHnswMerger — This merger merges graph in a concurrent manner, by using HnswConcurrentMergeBuilder C DenseNodesIterator — NodesIterator that enumerates [0, size) C FilteredHnswGraphSearcher — Searches an HNSW graph to find nearest neighbors to a query vector. C FloatHeap — A bounded min heap that stores floats. C GraphBuilderKnnCollector — A restricted, specialized knnCollector that can be used when building a graph. I HasKnnVectorValues — Implementors can return the KnnVectorValues from which their scorers read. I HnswBuilder — Interface for builder building the OnHeapHnswGraph C HnswConcurrentMergeBuilder — A graph builder that manages multiple workers, it only supports adding the whole graph all at once. C HnswGraph — Hierarchical Navigable Small World graph. C HnswGraphBuilder — Builder for HNSW graph. I HnswGraphMerger — Abstraction of merging multiple graphs into one on-heap graph C HnswGraphSearcher — Searches an HNSW graph to find nearest neighbors to a query vector. C HnswUtil — Utilities for use in tests involving HNSW graphs C IncrementalHnswGraphMerger — This merges multiple graphs in a single thread in incremental fashion. C InitializedHnswGraphBuilder — This creates a graph builder that is initialized with the provided HnswGraph. I IntToIntFunction — Native int to int function C MergingHnswGraphBuilder — A graph builder that is used during segments' merging. C NeighborArray — NeighborArray encodes the neighbors of a node and their mutual scores in the HNSW graph as a pair of growable arrays. C NeighborQueue — NeighborQueue uses a TernaryLongHeap to store lists of arcs in an HNSW graph, represented as a neighbor node id with an associated score packed together as a sortable long, which is sorted primarily by score. C NodesIterator — Iterator over the graph nodes on a certain level. C OnHeapHnswGraph — An HnswGraph where all nodes and connections are held in memory. C OrdinalTranslatedKnnCollector — Wraps a provided KnnCollector object, translating the provided vectorId ordinal to a documentId I RandomVectorScorer — A RandomVectorScorer for scoring random nodes in batches against an abstract query. I RandomVectorScorerSupplier — A supplier that creates RandomVectorScorer from an ordinal. C UpdateGraphsUtils — Utility class for updating a big graph with smaller graphs. I UpdateableRandomVectorScorer — Just like a RandomVectorScorer but allows the scoring ordinal to be changed.

C MutableValue — Base class for all mutable values. C MutableValueBool — MutableValue implementation of type boolean. C MutableValueDate — MutableValue implementation of type Date. C MutableValueDouble — MutableValue implementation of type double. C MutableValueFloat — MutableValue implementation of type float. C MutableValueInt — MutableValue implementation of type int. C MutableValueLong — MutableValue implementation of type long. C MutableValueStr — MutableValue implementation of type String.

C AbstractPagedMutable — Base implementation for PagedMutable and PagedGrowableWriter. C BlockPackedReaderIterator — Reader for sequences of longs written with BlockPackedWriter. C BlockPackedWriter — A writer for large sequences of longs. C Builder — A Builder for a PackedLongValues instance. I Decoder — A decoder for packed integers. C DirectMonotonicReader — Retrieves an instance previously written by DirectMonotonicWriter. C DirectMonotonicWriter — Write monotonically-increasing sequences of integers. C DirectReader — Retrieves an instance previously written by DirectWriter Example usage: int bitsPerValue = DirectWriter.bitsRequired(100); IndexInput in = dir.o C DirectWriter — Class for writing packed integers to be directly read from Directory. I Encoder — An encoder for packed integers. E Format — A format to write packed ints. R FormatAndBits — Simple class that holds a format and a number of bits per value. C GrowableWriter — Implements PackedInts.Mutable, but grows the bit count of the underlying packed ints on-demand. C Iterator — An iterator over long values. C Meta — In-memory metadata that needs to be kept around for DirectMonotonicReader to read data from disk. C MonotonicBlockPackedReader — Provides random access to a stream written with MonotonicBlockPackedWriter. C MonotonicBlockPackedWriter — A writer for large monotonically increasing sequences of positive longs. C Mutable — A packed integer array that can be modified. C NullReader — A Reader which has all its values equal to 0 (bitsPerValue = 0). C PackedDataInput — A DataInput wrapper to read unaligned, variable-length packed integers. C PackedDataOutput — A DataOutput wrapper to write unaligned, variable-length packed integers. C PackedInts — Simplistic compression for array of unsigned long values. C PackedLongValues — Utility class to compress integers into a LongValues instance. C PagedGrowableWriter — A PagedGrowableWriter. C PagedMutable — A PagedMutable. C Reader — A read-only random access array of positive integers. I ReaderIterator — Run-once iterator interface, to decode previously saved PackedInts. C Writer — A write-once Writer.

I ByteVectorComparator — Compares two byte vectors C DotProduct — Calculates dot product on quantized vectors, applying the appropriate corrections C Euclidean — Calculates euclidean distance on quantized vectors, applying the appropriate corrections C MaximumInnerProduct — Calculates max inner product on quantized vectors, applying the appropriate corrections C OptimizedScalarQuantizer — This is a scalar quantizer that optimizes the quantization intervals for a given vector. R QuantizationResult — Quantization result containing the lower and upper interval bounds, the additional correction C QuantizedByteVectorValues — A version of ByteVectorValues, but additionally retrieving score correction offset for Scalar quantization scores. I QuantizedVectorsReader — Quantized vector reader I ScalarQuantizedVectorSimilarity — Calculates and adjust the scores correctly for quantized vectors given the scalar quantization parameters C ScalarQuantizer — Will scalar quantize float vectors into `int8` byte values.

C AbstractIterator — Simplifies the implementation of iterators a bit. C BitMixer — Bit mixing utilities. C BufferAllocationException — BufferAllocationException forked from HPPC. C CharCursor — Forked from HPPC, holding int index and char value. C CharHashSet — A hash set of chars, implemented using open addressing with linear probing for collision resolution. C CharObjectCursor — Forked from HPPC, holding int index,key and value C CharObjectHashMap — A hash map of char to Object, implemented using open addressing with linear probing for collision resolution. C DoubleCursor — Forked from HPPC, holding int index and double value. C FloatArrayList — An array-backed list of float. C FloatCursor — Forked from HPPC, holding int index and float value. C IntArrayList — An array-backed list of int. C IntContainer — IntCursor iterable with size and toArray function implemented C IntCursor — Forked from HPPC, holding int index and int value. C IntDoubleCursor — Forked from HPPC, holding int index,key and value C IntDoubleHashMap — A hash map of int to double, implemented using open addressing with linear probing for collision resolution. C IntFloatCursor — Forked from HPPC, holding int index,key and value C IntFloatHashMap — A hash map of int to float, implemented using open addressing with linear probing for collision resolution. C IntHashSet — A hash set of ints, implemented using open addressing with linear probing for collision resolution. C IntIntCursor — Forked from HPPC, holding int index,key and value C IntIntHashMap — A hash map of int to int, implemented using open addressing with linear probing for collision resolution. C IntLongCursor — Forked from HPPC, holding int index,key and value C IntLongHashMap — A hash map of int to long, implemented using open addressing with linear probing for collision resolution. C IntObjectCursor — Forked from HPPC, holding int index,key and value C IntObjectHashMap — A hash map of int to Object, implemented using open addressing with linear probing for collision resolution. C KeysContainer — A view of the keys inside this hash map. C KeysContainer — A view of the keys inside this hash map. C KeysContainer — A view of the keys inside this hash map. C KeysContainer — A view of the keys inside this hash map. C KeysContainer — A view of the keys inside this hash map. C KeysContainer — A view of the keys inside this hash map. C KeysContainer — A view of the keys inside this hash map. C KeysContainer — A view of the keys inside this hash map. C KeysContainer — A view of the keys inside this hash map. C LongArrayList — An array-backed list of long. C LongCursor — Forked from HPPC, holding int index and long value. C LongFloatCursor — Forked from HPPC, holding int index,key and value C LongFloatHashMap — A hash map of long to float, implemented using open addressing with linear probing for collision resolution. C LongHashSet — A hash set of longs, implemented using open addressing with linear probing for collision resolution. C LongIntCursor — Forked from HPPC, holding int index,key and value C LongIntHashMap — A hash map of long to int, implemented using open addressing with linear probing for collision resolution. C LongObjectCursor — Forked from HPPC, holding int index,key and value C LongObjectHashMap — A hash map of long to Object, implemented using open addressing with linear probing for collision resolution. C MaxSizedFloatArrayList — An array-backed list of float with a maximum size limit. C MaxSizedIntArrayList — An array-backed list of int with a maximum size limit. C ObjectCursor — Forked from HPPC, holding int index and Object value. C ValuesContainer — A view over the set of values of this map. C ValuesContainer — A view over the set of values of this map. C ValuesContainer — A view over the set of values of this map. C ValuesContainer — A view over the set of values of this map. C ValuesContainer — A view over the set of values of this map. C ValuesContainer — A view over the set of values of this map. C ValuesContainer — A view over the set of values of this map. C ValuesContainer — A view over the set of values of this map.

I ConcurrentMergeSchedulerAccess — Access to org.apache.lucene.index.ConcurrentMergeScheduler internals exposed to the test framework. I FieldInfosBuilder — Public type exposing FieldInfo internal builders. I FilterIndexInputAccess — Access to org.apache.lucene.store.FilterIndexInput internals exposed to the test framework. I IndexPackageAccess — Access to org.apache.lucene.index package internals exposed to the test framework. I IndexWriterAccess — Access to org.apache.lucene.index.IndexWriter internals exposed to the test framework. I SegmentReaderAccess — Access to org.apache.lucene.index.SegmentReader internals exposed to the test framework. C TestSecrets — A set of static methods returning accessors for internal, package-private functionality in Lucene.

C PostingDecodingUtil — Utility class to decode postings. I VectorUtilSupport — Interface for implementations of VectorUtil support. C VectorizationProvider — A provider of vectorization implementations.