# Package org.apache.lucene.codecs.blockterms

package org.apache.lucene.codecs.blockterms
Pluggable term index / block terms dictionary implementations.

Classes
Class
Description
BlockTermsReader
Handles a terms dict, but decouples all details of doc/freqs/positions reading to an instance of `PostingsReaderBase`.
BlockTermsWriter
Writes terms dict, block-encoding (column stride) each term's metadata for each set of terms between two index terms.
FixedGapTermsIndexReader
TermsIndexReader for simple every Nth terms indexes.
FixedGapTermsIndexWriter
Selects every Nth term as and index term, and hold term bytes (mostly) fully expanded in memory.
TermsIndexReaderBase
`BlockTermsReader` interacts with an instance of this class to manage its terms index.
TermsIndexReaderBase.FieldIndexEnum
Similar to TermsEnum, except, the only "metadata" it reports for a given indexed term is the long fileOffset into the main terms dictionary file.
TermsIndexWriterBase
Base class for terms index implementations to plug into `BlockTermsWriter`.
VariableGapTermsIndexReader
See `VariableGapTermsIndexWriter`
VariableGapTermsIndexWriter
Selects index terms according to provided pluggable `VariableGapTermsIndexWriter.IndexTermSelector`, and stores them in a prefix trie that's loaded entirely in RAM stored as an FST.
VariableGapTermsIndexWriter.EveryNOrDocFreqTermSelector
Sets an index term when docFreq >= docFreqThresh, or every interval terms.
VariableGapTermsIndexWriter.EveryNTermSelector
Same policy as `FixedGapTermsIndexWriter`
VariableGapTermsIndexWriter.IndexTermSelector
Hook for selecting which terms should be placed in the terms index.