package org.apache.lucene.index;
/**
* Copyright 2007 The Apache Software Foundation
*
* Licensed 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.util.*;
/**
* Store a sorted collection of {@link org.apache.lucene.index.TermVectorEntry}s. Collects all term information
* into a single, SortedSet.
* <br/>
* NOTE: This Mapper ignores all Field information for the Document. This means that if you are using offset/positions you will not
* know what Fields they correlate with.
* <br/>
* This is not thread-safe
*/
public class SortedTermVectorMapper extends TermVectorMapper{
private SortedSet<TermVectorEntry> currentSet;
private Map<String,TermVectorEntry> termToTVE = new HashMap<String,TermVectorEntry>();
private boolean storeOffsets;
private boolean storePositions;
/**
* Stand-in name for the field in {@link TermVectorEntry}.
*/
public static final String ALL = "_ALL_";
/**
*
* @param comparator A Comparator for sorting {@link TermVectorEntry}s
*/
public SortedTermVectorMapper(Comparator<TermVectorEntry> comparator) {
this(false, false, comparator);
}
public SortedTermVectorMapper(boolean ignoringPositions, boolean ignoringOffsets, Comparator<TermVectorEntry> comparator) {
super(ignoringPositions, ignoringOffsets);
currentSet = new TreeSet<TermVectorEntry>(comparator);
}
/**
*
* @param term The term to map
* @param frequency The frequency of the term
* @param offsets Offset information, may be null
* @param positions Position information, may be null
*/
//We need to combine any previous mentions of the term
@Override
public void map(String term, int frequency, TermVectorOffsetInfo[] offsets, int[] positions) {
TermVectorEntry entry = termToTVE.get(term);
if (entry == null) {
entry = new TermVectorEntry(ALL, term, frequency,
storeOffsets == true ? offsets : null,
storePositions == true ? positions : null);
termToTVE.put(term, entry);
currentSet.add(entry);
} else {
entry.setFrequency(entry.getFrequency() + frequency);
if (storeOffsets)
{
TermVectorOffsetInfo [] existingOffsets = entry.getOffsets();
//A few diff. cases here: offsets is null, existing offsets is null, both are null, same for positions
if (existingOffsets != null && offsets != null && offsets.length > 0)
{
//copy over the existing offsets
TermVectorOffsetInfo [] newOffsets = new TermVectorOffsetInfo[existingOffsets.length + offsets.length];
System.arraycopy(existingOffsets, 0, newOffsets, 0, existingOffsets.length);
System.arraycopy(offsets, 0, newOffsets, existingOffsets.length, offsets.length);
entry.setOffsets(newOffsets);
}
else if (existingOffsets == null && offsets != null && offsets.length > 0)
{
entry.setOffsets(offsets);
}
//else leave it alone
}
if (storePositions)
{
int [] existingPositions = entry.getPositions();
if (existingPositions != null && positions != null && positions.length > 0)
{
int [] newPositions = new int[existingPositions.length + positions.length];
System.arraycopy(existingPositions, 0, newPositions, 0, existingPositions.length);
System.arraycopy(positions, 0, newPositions, existingPositions.length, positions.length);
entry.setPositions(newPositions);
}
else if (existingPositions == null && positions != null && positions.length > 0)
{
entry.setPositions(positions);
}
}
}
}
@Override
public void setExpectations(String field, int numTerms, boolean storeOffsets, boolean storePositions) {
this.storeOffsets = storeOffsets;
this.storePositions = storePositions;
}
/**
* The TermVectorEntrySet. A SortedSet of {@link TermVectorEntry} objects. Sort is by the comparator passed into the constructor.
*<br/>
* This set will be empty until after the mapping process takes place.
*
* @return The SortedSet of {@link TermVectorEntry}.
*/
public SortedSet<TermVectorEntry> getTermVectorEntrySet()
{
return currentSet;
}
}