# Package org.apache.lucene.backward_codecs.lucene101

package org.apache.lucene.backward_codecs.lucene101
Lucene 10.1 file format.

- Related Packages
  Package
  Description
  org.apache.lucene.backward_codecs
  Common APIs for use by backwards compatibility codecs.
- Class
  Description
  ForDeltaUtil
  Inspired from https://fulmicoton.com/posts/bitpacking/ Encodes multiple integers in a Java int to get SIMD-like speedups.
  ForUtil
  Inspired from https://fulmicoton.com/posts/bitpacking/ Encodes multiple integers in one to get SIMD-like speedups.
  Lucene101Codec
  Implements the Lucene 10.1 index format
  Lucene101Codec.Mode
  Configuration option for the codec.
  Lucene101PostingsFormat
  Lucene 10.1 postings format, which encodes postings in packed integer blocks for fast decode.
  Lucene101PostingsFormat.IntBlockTermState
  Holds all state required for `Lucene101PostingsReader` to produce a `PostingsEnum` without re-seeking the terms dict.
  Lucene101PostingsReader
  Concrete class that reads docId(maybe frq,pos,offset,payloads) list with postings format.