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Lucene example source code file (TermsHash.java)

This example Lucene source code file (TermsHash.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

collection, collection, documentswriter, hashmap, hashset, io, map, override, override, termshash, termshash, termshashconsumer, termshashperfield, termshashperthread, termshashperthread, util

The Lucene TermsHash.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 java.io.IOException;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;

/** This class implements {@link InvertedDocConsumer}, which
 *  is passed each token produced by the analyzer on each
 *  field.  It stores these tokens in a hash table, and
 *  allocates separate byte streams per token.  Consumers of
 *  this class, eg {@link FreqProxTermsWriter} and {@link
 *  TermVectorsTermsWriter}, write their own byte streams
 *  under each term.
final class TermsHash extends InvertedDocConsumer {

  final TermsHashConsumer consumer;
  final TermsHash nextTermsHash;
  final DocumentsWriter docWriter;

  boolean trackAllocations;

  public TermsHash(final DocumentsWriter docWriter, boolean trackAllocations, final TermsHashConsumer consumer, final TermsHash nextTermsHash) {
    this.docWriter = docWriter;
    this.consumer = consumer;
    this.nextTermsHash = nextTermsHash;
    this.trackAllocations = trackAllocations;

  InvertedDocConsumerPerThread addThread(DocInverterPerThread docInverterPerThread) {
    return new TermsHashPerThread(docInverterPerThread, this, nextTermsHash, null);

  TermsHashPerThread addThread(DocInverterPerThread docInverterPerThread, TermsHashPerThread primaryPerThread) {
    return new TermsHashPerThread(docInverterPerThread, this, nextTermsHash, primaryPerThread);

  void setFieldInfos(FieldInfos fieldInfos) {
    this.fieldInfos = fieldInfos;

  public void abort() {
    try {
    } finally {
      if (nextTermsHash != null) {

  synchronized void flush(Map<InvertedDocConsumerPerThread,Collection threadsAndFields, final SegmentWriteState state) throws IOException {
    Map<TermsHashConsumerPerThread,Collection childThreadsAndFields = new HashMap>();
    Map<InvertedDocConsumerPerThread,Collection nextThreadsAndFields;

    if (nextTermsHash != null)
      nextThreadsAndFields = new HashMap<InvertedDocConsumerPerThread,Collection();
      nextThreadsAndFields = null;

    for (final Map.Entry<InvertedDocConsumerPerThread,Collection entry : threadsAndFields.entrySet()) {

      TermsHashPerThread perThread = (TermsHashPerThread) entry.getKey();

      Collection<InvertedDocConsumerPerField> fields = entry.getValue();

      Iterator<InvertedDocConsumerPerField> fieldsIt = fields.iterator();
      Collection<TermsHashConsumerPerField> childFields = new HashSet();
      Collection<InvertedDocConsumerPerField> nextChildFields;

      if (nextTermsHash != null)
        nextChildFields = new HashSet<InvertedDocConsumerPerField>();
        nextChildFields = null;

      while(fieldsIt.hasNext()) {
        TermsHashPerField perField = (TermsHashPerField) fieldsIt.next();
        if (nextTermsHash != null)

      childThreadsAndFields.put(perThread.consumer, childFields);
      if (nextTermsHash != null)
        nextThreadsAndFields.put(perThread.nextPerThread, nextChildFields);
    consumer.flush(childThreadsAndFields, state);

    if (nextTermsHash != null)
      nextTermsHash.flush(nextThreadsAndFields, state);

  synchronized public boolean freeRAM() {
    return false;

Other Lucene examples (source code examples)

Here is a short list of links related to this Lucene TermsHash.java source code file:

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