content: package org.apache.lucene.analysis.path;
  /**
   * 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 java.io.Reader;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.lucene.analysis.Tokenizer;
  import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
  import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
  import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
  
  /**
   *
   * Take something like:
   *
   * <pre>
   * www.site.co.uk
   * </pre>
   *
   * and make:
   *
   * <pre>
   * www.site.co.uk
   * site.co.uk
   * co.uk
   * uk
   * </pre>
   *
   */
  public class ReversePathHierarchyTokenizer extends Tokenizer {
  
    public ReversePathHierarchyTokenizer(Reader input) {
      this(input, DEFAULT_BUFFER_SIZE, DEFAULT_DELIMITER, DEFAULT_DELIMITER, DEFAULT_SKIP);
    }
  
    public ReversePathHierarchyTokenizer(Reader input, int skip) {
      this(input, DEFAULT_BUFFER_SIZE, DEFAULT_DELIMITER, DEFAULT_DELIMITER, skip);
    }
  
    public ReversePathHierarchyTokenizer(Reader input, int bufferSize, char delimiter) {
      this(input, bufferSize, delimiter, delimiter, DEFAULT_SKIP);
    }
  
    public ReversePathHierarchyTokenizer(Reader input, char delimiter, char replacement) {
      this(input, DEFAULT_BUFFER_SIZE, delimiter, replacement, DEFAULT_SKIP);
    }
  
    public ReversePathHierarchyTokenizer(Reader input, int bufferSize, char delimiter, char replacement) {
      this(input, bufferSize, delimiter, replacement, DEFAULT_SKIP);
    }
  
    public ReversePathHierarchyTokenizer(Reader input, char delimiter, int skip) {
      this(input, DEFAULT_BUFFER_SIZE, delimiter, delimiter, skip);
    }
  
    public ReversePathHierarchyTokenizer(Reader input, char delimiter, char replacement, int skip) {
      this(input, DEFAULT_BUFFER_SIZE, delimiter, replacement, skip);
    }
  
    public ReversePathHierarchyTokenizer(Reader input, int bufferSize, char delimiter, char replacement, int skip) {
      super(input);
      termAtt.resizeBuffer(bufferSize);
      this.delimiter = delimiter;
      this.replacement = replacement;
      this.skip = skip;
      resultToken = new StringBuilder(bufferSize);
      resultTokenBuffer = new char[bufferSize];
      delimiterPositions = new ArrayList<Integer>(bufferSize/10);
    }
  
    private static final int DEFAULT_BUFFER_SIZE = 1024;
    public static final char DEFAULT_DELIMITER = '/';
    public static final int DEFAULT_SKIP = 0;
  
    private final char delimiter;
    private final char replacement;
    private final int skip;
  
    private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
    private final OffsetAttribute offsetAtt = addAttribute(OffsetAttribute.class);
    private final PositionIncrementAttribute posAtt = addAttribute(PositionIncrementAttribute.class);
    
    private int endPosition = 0;
    private int finalOffset = 0;
    private int skipped = 0;
    private StringBuilder resultToken;
  
    private List<Integer> delimiterPositions;
    private int delimitersCount = -1;
    private char[] resultTokenBuffer;
  
    @Override
    public final boolean incrementToken() throws IOException {
      clearAttributes();
      if(delimitersCount == -1){
        int length = 0;
        delimiterPositions.add(0);
        while (true) {
          int c = input.read();
          if( c < 0 ) {
            break;
          }
          length++;
          if( c == delimiter ) {
            delimiterPositions.add(length);
            resultToken.append(replacement);
          }
          else{
            resultToken.append((char)c);
          }
        }
        delimitersCount = delimiterPositions.size();
        if( delimiterPositions.get(delimitersCount-1) < length ){
          delimiterPositions.add(length);
          delimitersCount++;
        }
        if( resultTokenBuffer.length < resultToken.length() ){
          resultTokenBuffer = new char[resultToken.length()];
        }
        resultToken.getChars(0, resultToken.length(), resultTokenBuffer, 0);
        resultToken.setLength(0);
        endPosition = delimiterPositions.get(delimitersCount-1 - skip);
        finalOffset = correctOffset(length);
        posAtt.setPositionIncrement(1);
      }
      else{
        posAtt.setPositionIncrement(0);
      }
  
      while( skipped < delimitersCount-skip-1 ){
        int start = delimiterPositions.get(skipped);
        termAtt.copyBuffer(resultTokenBuffer, start, endPosition - start);
        offsetAtt.setOffset(correctOffset(start), correctOffset(endPosition));
        skipped++;
        return true;
      }
  
      return false;
    }
  
    @Override
    public final void end() {
      // set final offset
      offsetAtt.setOffset(finalOffset, finalOffset);
    }
  
    @Override
    public void reset(Reader input) throws IOException {
      super.reset(input);
      resultToken.setLength(0);
      finalOffset = 0;
      skipped = 0;
      delimitersCount = -1;
      delimiterPositions.clear();
    }
  }
  