Lucene example source code file (FreqProxFieldMergeState.java)

This example Lucene source code file (FreqProxFieldMergeState.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

byteslicereader, byteslicereader, charblockpool, freqproxfieldmergestate, freqproxpostingsarray, freqproxpostingsarray, freqproxtermswriterperfield, io, ioexception, ioexception, string, string

The Lucene FreqProxFieldMergeState.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,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.IOException;

import org.apache.lucene.index.FreqProxTermsWriterPerField.FreqProxPostingsArray;

// TODO FI: some of this is "generic" to TermsHash* so we
// should factor it out so other consumers don't have to
// duplicate this code

/** Used by DocumentsWriter to merge the postings from
 *  multiple ThreadStates when creating a segment */
final class FreqProxFieldMergeState {

  final FreqProxTermsWriterPerField field;
  final int numPostings;
  final CharBlockPool charPool;
  final int[] termIDs;
  final FreqProxPostingsArray postings;
  int currentTermID;
  
  char[] text;
  int textOffset;

  private int postingUpto = -1;

  final ByteSliceReader freq = new ByteSliceReader();
  final ByteSliceReader prox = new ByteSliceReader();

  int docID;
  int termFreq;

  public FreqProxFieldMergeState(FreqProxTermsWriterPerField field) {
    this.field = field;
    this.charPool = field.perThread.termsHashPerThread.charPool;
    this.numPostings = field.termsHashPerField.numPostings;
    this.termIDs = field.termsHashPerField.sortPostings();
    this.postings = (FreqProxPostingsArray) field.termsHashPerField.postingsArray;
  }

  boolean nextTerm() throws IOException {
    postingUpto++;
    if (postingUpto == numPostings)
      return false;

    currentTermID = termIDs[postingUpto];
    docID = 0;

    final int textStart = postings.textStarts[currentTermID];
    text = charPool.buffers[textStart >> DocumentsWriter.CHAR_BLOCK_SHIFT];
    textOffset = textStart & DocumentsWriter.CHAR_BLOCK_MASK;

    field.termsHashPerField.initReader(freq, currentTermID, 0);
    if (!field.fieldInfo.omitTermFreqAndPositions)
      field.termsHashPerField.initReader(prox, currentTermID, 1);

    // Should always be true
    boolean result = nextDoc();
    assert result;

    return true;
  }

  public String termText() {
    int upto = textOffset;
    while(text[upto] != 0xffff) {
      upto++;
    }
    return new String(text, textOffset, upto-textOffset);
  }

  public boolean nextDoc() throws IOException {
    if (freq.eof()) {
      if (postings.lastDocCodes[currentTermID] != -1) {
        // Return last doc
        docID = postings.lastDocIDs[currentTermID];
        if (!field.omitTermFreqAndPositions)
          termFreq = postings.docFreqs[currentTermID];
        postings.lastDocCodes[currentTermID] = -1;
        return true;
      } else
        // EOF
        return false;
    }

    final int code = freq.readVInt();
    if (field.omitTermFreqAndPositions)
      docID += code;
    else {
      docID += code >>> 1;
      if ((code & 1) != 0)
        termFreq = 1;
      else
        termFreq = freq.readVInt();
    }

    assert docID != postings.lastDocIDs[currentTermID];

    return true;
  }
}