/*
* 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.
*/
package org.apache.solr.spelling;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.Token;
import org.apache.lucene.search.spell.StringDistance;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.core.SolrCore;
import org.apache.solr.handler.component.SpellCheckMergeData;
import org.apache.solr.search.SolrIndexSearcher;
/**
* <p>This class lets a query be run through multiple spell checkers.
* The initial use-case is to use {@link WordBreakSolrSpellChecker}
* in conjunction with a "standard" spell checker
* (such as {@link DirectSolrSpellChecker}
* </p>
*/
public class ConjunctionSolrSpellChecker extends SolrSpellChecker {
private StringDistance stringDistance = null;
private Float accuracy = null;
private String dictionaryName = null;
private Analyzer queryAnalyzer = null;
private List<SolrSpellChecker> checkers = new ArrayList<>();
private boolean initialized = false;
public void addChecker(SolrSpellChecker checker) {
if (initialized) {
throw new IllegalStateException(
"Need to add checkers before calling init()");
}
try {
if (stringDistance == null) {
stringDistance = checker.getStringDistance();
} else if (!stringDistance.equals(checker.getStringDistance())) {
throw new IllegalArgumentException(
"All checkers need to use the same StringDistance.");
}
} catch (UnsupportedOperationException uoe) {
// ignore
}
try {
if (accuracy == null) {
accuracy = checker.getAccuracy();
} else if (accuracy != checker.getAccuracy()) {
throw new IllegalArgumentException(
"All checkers need to use the same Accuracy.");
}
} catch (UnsupportedOperationException uoe) {
// ignore
}
if (queryAnalyzer == null) {
queryAnalyzer = checker.getQueryAnalyzer();
} else if (queryAnalyzer != checker.getQueryAnalyzer()) {
throw new IllegalArgumentException(
"All checkers need to use the same Analyzer.");
}
checkers.add(checker);
}
@SuppressWarnings("unchecked")
@Override
public String init(NamedList config, SolrCore core) {
for (int i = 0; i < checkers.size(); i++) {
SolrSpellChecker c = checkers.get(i);
String dn = c.init(config, core);
//TODO: in the future, we could develop this further to allow
// multiple spellcheckers with per-field dictionaries...
if (dictionaryName != null && !dictionaryName.equals(dn)) {
throw new IllegalArgumentException(
"Cannot have more than one dictionary. (" + dn + " , "
+ dictionaryName + ")");
}
dictionaryName = dn;
}
if (dictionaryName == null) {
dictionaryName = DEFAULT_DICTIONARY_NAME;
}
initialized = true;
return dictionaryName;
}
@Override
public void build(SolrCore core, SolrIndexSearcher searcher) throws IOException {
for (SolrSpellChecker c : checkers) {
c.build(core, searcher);
}
}
@Override
public SpellingResult getSuggestions(SpellingOptions options)
throws IOException {
SpellingResult[] results = new SpellingResult[checkers.size()];
for (int i = 0; i < checkers.size(); i++) {
results[i] = checkers.get(i).getSuggestions(options);
}
return mergeCheckers(results, options.count);
}
@Override
public SpellingResult mergeSuggestions(SpellCheckMergeData mergeData,
int numSug, int count, boolean extendedResults) {
SpellingResult[] results = new SpellingResult[checkers.size()];
for (int i = 0; i < checkers.size(); i++) {
results[i] = checkers.get(i).mergeSuggestions(mergeData, numSug, count,
extendedResults);
}
return mergeCheckers(results, numSug);
}
//TODO: This just interleaves the results. In the future, we might want to let users give each checker its
// own weight and use that in combination to score & frequency to sort the results ?
private SpellingResult mergeCheckers(SpellingResult[] results, int numSug) {
Map<Token, Integer> combinedTokenFrequency = new HashMap<>();
Map<Token, List<LinkedHashMap<String, Integer>>> allSuggestions = new LinkedHashMap<>();
for(SpellingResult result : results) {
if(result.getTokenFrequency()!=null) {
combinedTokenFrequency.putAll(result.getTokenFrequency());
}
for(Map.Entry<Token, LinkedHashMap<String, Integer>> entry : result.getSuggestions().entrySet()) {
List<LinkedHashMap<String, Integer>> allForThisToken = allSuggestions.get(entry.getKey());
if(allForThisToken==null) {
allForThisToken = new ArrayList<>();
allSuggestions.put(entry.getKey(), allForThisToken);
}
allForThisToken.add(entry.getValue());
}
}
SpellingResult combinedResult = new SpellingResult();
for(Map.Entry<Token, List<LinkedHashMap<String, Integer>>> entry : allSuggestions.entrySet()) {
Token original = entry.getKey();
List<Iterator<Map.Entry<String,Integer>>> corrIters = new ArrayList<>(entry.getValue().size());
for(LinkedHashMap<String, Integer> corrections : entry.getValue()) {
corrIters.add(corrections.entrySet().iterator());
}
int numberAdded = 0;
while(numberAdded < numSug) {
boolean anyData = false;
for(Iterator<Map.Entry<String,Integer>> iter : corrIters) {
if(iter.hasNext()) {
anyData = true;
Map.Entry<String,Integer> corr = iter.next();
combinedResult.add(original, corr.getKey(), corr.getValue());
Integer tokenFrequency = combinedTokenFrequency.get(original);
combinedResult.addFrequency(original, tokenFrequency==null ? 0 : tokenFrequency);
if(++numberAdded==numSug) {
break;
}
}
}
if(!anyData) {
if(numberAdded==0) {
combinedResult.add(original, Collections.<String>emptyList());
Integer tokenFrequency = combinedTokenFrequency.get(original);
combinedResult.addFrequency(original, tokenFrequency==null ? 0 : tokenFrequency);
}
break;
}
}
}
return combinedResult;
}
@Override
public void reload(SolrCore core, SolrIndexSearcher searcher)
throws IOException {
for (SolrSpellChecker c : checkers) {
c.reload(core, searcher);
}
}
@Override
public Analyzer getQueryAnalyzer() {
return queryAnalyzer;
}
@Override
public String getDictionaryName() {
return dictionaryName;
}
@Override
protected float getAccuracy() {
if (accuracy == null) {
return super.getAccuracy();
}
return accuracy;
}
@Override
protected StringDistance getStringDistance() {
if (stringDistance == null) {
return super.getStringDistance();
}
return stringDistance;
}
@Override
public boolean isSuggestionsMayOverlap() {
return true;
}
}