package org.apache.lucene.search.vectorhighlight;
/**
* 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.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import org.apache.lucene.search.vectorhighlight.FieldQuery.QueryPhraseMap;
import org.apache.lucene.search.vectorhighlight.FieldTermStack.TermInfo;
/**
* FieldPhraseList has a list of WeightedPhraseInfo that is used by FragListBuilder
* to create a FieldFragList object.
*/
public class FieldPhraseList {
LinkedList<WeightedPhraseInfo> phraseList = new LinkedList<WeightedPhraseInfo>();
/**
* a constructor.
*
* @param fieldTermStack FieldTermStack object
* @param fieldQuery FieldQuery object
*/
public FieldPhraseList( FieldTermStack fieldTermStack, FieldQuery fieldQuery ){
final String field = fieldTermStack.getFieldName();
LinkedList<TermInfo> phraseCandidate = new LinkedList<TermInfo>();
QueryPhraseMap currMap = null;
QueryPhraseMap nextMap = null;
while( !fieldTermStack.isEmpty() ){
phraseCandidate.clear();
TermInfo ti = fieldTermStack.pop();
currMap = fieldQuery.getFieldTermMap( field, ti.getText() );
// if not found, discard top TermInfo from stack, then try next element
if( currMap == null ) continue;
// if found, search the longest phrase
phraseCandidate.add( ti );
while( true ){
ti = fieldTermStack.pop();
nextMap = null;
if( ti != null )
nextMap = currMap.getTermMap( ti.getText() );
if( ti == null || nextMap == null ){
if( ti != null )
fieldTermStack.push( ti );
if( currMap.isValidTermOrPhrase( phraseCandidate ) ){
addIfNoOverlap( new WeightedPhraseInfo( phraseCandidate, currMap.getBoost(), currMap.getTermOrPhraseNumber() ) );
}
else{
while( phraseCandidate.size() > 1 ){
fieldTermStack.push( phraseCandidate.removeLast() );
currMap = fieldQuery.searchPhrase( field, phraseCandidate );
if( currMap != null ){
addIfNoOverlap( new WeightedPhraseInfo( phraseCandidate, currMap.getBoost(), currMap.getTermOrPhraseNumber() ) );
break;
}
}
}
break;
}
else{
phraseCandidate.add( ti );
currMap = nextMap;
}
}
}
}
void addIfNoOverlap( WeightedPhraseInfo wpi ){
for( WeightedPhraseInfo existWpi : phraseList ){
if( existWpi.isOffsetOverlap( wpi ) ) return;
}
phraseList.add( wpi );
}
public static class WeightedPhraseInfo {
String text; // unnecessary member, just exists for debugging purpose
List<Toffs> termsOffsets; // usually termsOffsets.size() == 1,
// but if position-gap > 1 and slop > 0 then size() could be greater than 1
float boost; // query boost
int seqnum;
public WeightedPhraseInfo( LinkedList<TermInfo> terms, float boost ){
this( terms, boost, 0 );
}
public WeightedPhraseInfo( LinkedList<TermInfo> terms, float boost, int number ){
this.boost = boost;
this.seqnum = number;
termsOffsets = new ArrayList<Toffs>( terms.size() );
TermInfo ti = terms.get( 0 );
termsOffsets.add( new Toffs( ti.getStartOffset(), ti.getEndOffset() ) );
if( terms.size() == 1 ){
text = ti.getText();
return;
}
StringBuilder sb = new StringBuilder();
sb.append( ti.getText() );
int pos = ti.getPosition();
for( int i = 1; i < terms.size(); i++ ){
ti = terms.get( i );
sb.append( ti.getText() );
if( ti.getPosition() - pos == 1 ){
Toffs to = termsOffsets.get( termsOffsets.size() - 1 );
to.setEndOffset( ti.getEndOffset() );
}
else{
termsOffsets.add( new Toffs( ti.getStartOffset(), ti.getEndOffset() ) );
}
pos = ti.getPosition();
}
text = sb.toString();
}
public int getStartOffset(){
return termsOffsets.get( 0 ).startOffset;
}
public int getEndOffset(){
return termsOffsets.get( termsOffsets.size() - 1 ).endOffset;
}
public boolean isOffsetOverlap( WeightedPhraseInfo other ){
int so = getStartOffset();
int eo = getEndOffset();
int oso = other.getStartOffset();
int oeo = other.getEndOffset();
if( so <= oso && oso < eo ) return true;
if( so < oeo && oeo <= eo ) return true;
if( oso <= so && so < oeo ) return true;
if( oso < eo && eo <= oeo ) return true;
return false;
}
@Override
public String toString(){
StringBuilder sb = new StringBuilder();
sb.append( text ).append( '(' ).append( boost ).append( ")(" );
for( Toffs to : termsOffsets ){
sb.append( to );
}
sb.append( ')' );
return sb.toString();
}
public static class Toffs {
int startOffset;
int endOffset;
public Toffs( int startOffset, int endOffset ){
this.startOffset = startOffset;
this.endOffset = endOffset;
}
public void setEndOffset( int endOffset ){
this.endOffset = endOffset;
}
public int getStartOffset(){
return startOffset;
}
public int getEndOffset(){
return endOffset;
}
@Override
public String toString(){
StringBuilder sb = new StringBuilder();
sb.append( '(' ).append( startOffset ).append( ',' ).append( endOffset ).append( ')' );
return sb.toString();
}
}
}
}