Package org.terrier.structures

Provides the interfaces for the index data structures used for retrieval with the Terrier platform.

These include the APIs of the inverted index, the direct index, the lexicon and the document index, as well as the Posting objects

Interface Summary

Interface	Description
BitFilePosition	A (number of bytes, number of bits) position in a bit file.
BitIndexPointer	A Pointer specialisation for some PostingIndex structures.
BlockEntryStatistics	Deprecated.
DocumentIndex	Interface for a document index.
EntryStatistics	An interface for basic statistics about a lexicon entry.
FieldDocumentIndex	Interface for a fields document index
FieldEntryStatistics	The statistics for a field entry.
IndexConfigurable	Interface defining that an index structure wants access to the Index object it is associated with.
IndexFactory.IndexLoader
MapLexicon.Id2EntryIndexLookup	Interface for getting the lexicon term index for a given term id
MetaIndex	Interface for document metadata.
NgramEntryStatistics	Represent statistics of n-grams, such as those used in sequence dependence models.
Pointer	A base interface for all pointers.
PostingIndex<POINTERTYPE extends Pointer>	An interface for accessing a posting list.
PostingIndexInputStream	Interface for reading postings from an input stream
Skipable	Deprecated.

Class Summary

Class	Description
AbstractPostingOutputStream	Abstract class that is extended by other posting output stream implementations
BaseCompressingMetaIndex	A MetaIndex implementation that compresses contents.
BaseCompressingMetaIndex.InputStream	An iterator for reading a MetaIndex as a stream
BasicDocumentIndexEntry	A basic document index entry.
BasicDocumentIndexEntry.Factory	Returna a factory for creating document index entries
BasicLexiconEntry	Contains all the information about one entry in the Lexicon.
BasicLexiconEntry.Factory	Factory for creating LexiconEntry objects
BasicTermStatsLexiconEntry	A LexiconEntry which only contains EntryStatistics
CollectionStatistics	This class provides basic statistics for the indexed collection of documents, such as the average length of documents, or the total number of documents in the collection.
CompressingMetaIndex	Implementation of BaseCompressingMetaIndex that uses Zlib deflate algorithm to compress entries
CompressingMetaIndex.InputStream
ConcurrentIndexLoader	An index loader for index references for indices that we wish to be thread safe
DocumentIndexEntry	A document index entry.
FieldDocumentIndexEntry	A document index entry for use with fields
FieldDocumentIndexEntry.Factory	Factory for creating a field document index entry
FieldLexiconEntry	A LexiconEntry with field support
FieldLexiconEntry.Factory	Factory for a LexiconEntry
FilePosition	Models a position within a file as the offset in bytes and the offset in bits in that byte.
FSADocumentIndex	Document Index saved as a fixed size array
FSADocumentIndex.FSADocumentIndexIterator	Gets an iterator over the documents in this index
FSADocumentIndexInMem	A DocumentIndex implementation that loads everything in memory.
FSADocumentIndexInMemFields	A version of FSADocumentIndexInMem for indices with fields.
FSAFieldDocumentIndex	Fields document index stored as a fixed size array
FSOMapFileLexicon	Instance of a Lexicon<String> where a FSOrderedMapFile is always used as a backing store.
FSOMapFileLexicon.MapFileLexiconEntryIterator
FSOMapFileLexicon.MapFileLexiconIterator
FSOMapFileLexiconGeneric<K1,K2 extends org.apache.hadoop.io.WritableComparable>
FSOMapFileLexiconGeneric.MapFileLexiconEntryIterator<T extends org.apache.hadoop.io.WritableComparable<?>>	Iterate through the values in order
FSOMapFileLexiconGeneric.MapFileLexiconIterator<T1,T2 extends org.apache.hadoop.io.WritableComparable<?>>	An iterator over the lexicon
FSOMapFileLexiconOutputStream	A LexiconOutputStream for FSOMapFileLexicon.
FSOMapFileLexiconOutputStreamGeneric<T1,T2 extends org.apache.hadoop.io.WritableComparable<?>>
Index	Base class for all Index implementations
Index.DirectIndexRef
IndexFactory	This is the main developer API for loading an index.
IndexFactory.DirectIndexLoader
IndexOnDisk	The replacement for what was Index in earlier Terrier versions.
IndexOnDisk.DiskIndexLoader
IndexStatsCommand
IndexUtil	Class with handy utilities for use on an Index.
IndexUtil.Command
Lexicon<KEY>	A lexicon (a.k.a.
Lexicon.LexiconFileEntry<KEY2>
LexiconEntry	Base class for all LexiconEntry implementations.
LexiconOutputStream<KEY>	This class implements an output stream for the lexicon structure.
LexiconUtil	Lexicon utilities class.
LZ4CompressedMetaIndex	MetaIndex implementation for when records are compressed using LZ4
LZ4CompressedMetaIndex.InputStream
MapLexicon<K1,K2 extends org.apache.hadoop.io.WritableComparable>	Implementation of a lexicon.
MapLexicon.IdIsIndex	Lexicon map where the termid is the term index
NonIncrementalDocumentIndexEntry	This class is created to represent a DocumentIndexEntry that do not assume an incremental docids, but instead maintains the docid.
NonIncrementalDocumentIndexEntry.Factory	Returna a factory for creating document index entries
PropertiesIndex	This class encapsulates all the Indexes at retrieval time.
SimpleBitIndexPointer	An implementation of a BitIndexPointer.
SimpleBitIndexPointer.Factory	Factory class for SimpleBitIndexPointer.
SimpleDocumentIndexEntry	A document index entry that doesn't write out direct index offset.
SimpleDocumentIndexEntry.Factory	Factory for the creation of DocumentIndexEntry objects
SimpleNgramEntryStatistics
UncompressedMetaIndex
UncompressedMetaIndex.InputStream
ZstdCompressedMetaIndex	MetaIndex implementation for when records are compressed using Zstandard
ZstdCompressedMetaIndex.InputStream

Annotation Types Summary

Annotation Type	Description
ConcurrentReadable	This annotation makes that an index data structure can be read by more than one thread concurrently.