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Lucene example source code file (NormsWriterPerField.java)

This example Lucene source code file (NormsWriterPerField.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Lucene tags/keywords

comparable, docinverterperfield, fieldinfo, fieldinfo, fieldinvertstate, inverteddocendconsumerperfield, normswriterperfield, normswriterperfield, normswriterperthread, normswriterperthread, override, override

The Lucene NormsWriterPerField.java source code

package org.apache.lucene.index;

 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *     http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * See the License for the specific language governing permissions and
 * limitations under the License.

import org.apache.lucene.util.ArrayUtil;
import org.apache.lucene.search.Similarity;

/** Taps into DocInverter, as an InvertedDocEndConsumer,
 *  which is called at the end of inverting each field.  We
 *  just look at the length for the field (docState.length)
 *  and record the norm. */

final class NormsWriterPerField extends InvertedDocEndConsumerPerField implements Comparable<NormsWriterPerField> {

  final NormsWriterPerThread perThread;
  final FieldInfo fieldInfo;
  final DocumentsWriter.DocState docState;

  // Holds all docID/norm pairs we've seen
  int[] docIDs = new int[1];
  byte[] norms = new byte[1];
  int upto;

  final FieldInvertState fieldState;

  public void reset() {
    // Shrink back if we are overallocated now:
    docIDs = ArrayUtil.shrink(docIDs, upto);
    norms = ArrayUtil.shrink(norms, upto);
    upto = 0;

  public NormsWriterPerField(final DocInverterPerField docInverterPerField, final NormsWriterPerThread perThread, final FieldInfo fieldInfo) {
    this.perThread = perThread;
    this.fieldInfo = fieldInfo;
    docState = perThread.docState;
    fieldState = docInverterPerField.fieldState;

  void abort() {
    upto = 0;

  public int compareTo(NormsWriterPerField other) {
    return fieldInfo.name.compareTo(other.fieldInfo.name);
  void finish() {
    if (fieldInfo.isIndexed && !fieldInfo.omitNorms) {
      if (docIDs.length <= upto) {
        assert docIDs.length == upto;
        docIDs = ArrayUtil.grow(docIDs, 1+upto);
      if (norms.length <= upto) {
        assert norms.length == upto;
        norms = ArrayUtil.grow(norms, 1+upto);
      final float norm = docState.similarity.computeNorm(fieldInfo.name, fieldState);
      norms[upto] = docState.similarity.encodeNormValue(norm);
      docIDs[upto] = docState.docID;

Other Lucene examples (source code examples)

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