/*
* 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.lucene.search.spell;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Locale;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.MockAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.store.AlreadyClosedException;
import org.apache.lucene.store.Directory;
import org.apache.lucene.util.English;
import org.apache.lucene.util.LuceneTestCase;
import org.apache.lucene.util.NamedThreadFactory;
/**
* Spell checker test case
*/
public class TestSpellChecker extends LuceneTestCase {
private SpellCheckerMock spellChecker;
private Directory userindex, spellindex;
private Analyzer analyzer;
private List<IndexSearcher> searchers;
@Override
public void setUp() throws Exception {
super.setUp();
//create a user index
userindex = newDirectory();
analyzer = new MockAnalyzer(random());
IndexWriter writer = new IndexWriter(userindex, new IndexWriterConfig(analyzer));
for (int i = 0; i < 1000; i++) {
Document doc = new Document();
doc.add(newTextField("field1", English.intToEnglish(i), Field.Store.YES));
doc.add(newTextField("field2", English.intToEnglish(i + 1), Field.Store.YES)); // + word thousand
doc.add(newTextField("field3", "fvei" + (i % 2 == 0 ? " five" : ""), Field.Store.YES)); // + word thousand
writer.addDocument(doc);
}
{
Document doc = new Document();
doc.add(newTextField("field1", "eight", Field.Store.YES)); // "eight" in
// the index
// twice
writer.addDocument(doc);
}
{
Document doc = new Document();
doc
.add(newTextField("field1", "twenty-one twenty-one", Field.Store.YES)); // "twenty-one" in the index thrice
writer.addDocument(doc);
}
{
Document doc = new Document();
doc.add(newTextField("field1", "twenty", Field.Store.YES)); // "twenty"
// in the
// index
// twice
writer.addDocument(doc);
}
writer.close();
searchers = Collections.synchronizedList(new ArrayList<IndexSearcher>());
// create the spellChecker
spellindex = newDirectory();
spellChecker = new SpellCheckerMock(spellindex);
}
@Override
public void tearDown() throws Exception {
userindex.close();
if (!spellChecker.isClosed())
spellChecker.close();
spellindex.close();
analyzer.close();
super.tearDown();
}
public void testBuild() throws IOException {
IndexReader r = DirectoryReader.open(userindex);
spellChecker.clearIndex();
addwords(r, spellChecker, "field1");
int num_field1 = this.numdoc();
addwords(r, spellChecker, "field2");
int num_field2 = this.numdoc();
assertEquals(num_field2, num_field1 + 1);
assertLastSearcherOpen(4);
checkCommonSuggestions(r);
checkLevenshteinSuggestions(r);
spellChecker.setStringDistance(new JaroWinklerDistance());
spellChecker.setAccuracy(0.8f);
checkCommonSuggestions(r);
checkJaroWinklerSuggestions();
// the accuracy is set to 0.8 by default, but the best result has a score of 0.925
String[] similar = spellChecker.suggestSimilar("fvie", 2, 0.93f);
assertTrue(similar.length == 0);
similar = spellChecker.suggestSimilar("fvie", 2, 0.92f);
assertTrue(similar.length == 1);
similar = spellChecker.suggestSimilar("fiv", 2);
assertTrue(similar.length > 0);
assertEquals(similar[0], "five");
spellChecker.setStringDistance(new NGramDistance(2));
spellChecker.setAccuracy(0.5f);
checkCommonSuggestions(r);
checkNGramSuggestions();
r.close();
}
public void testComparator() throws Exception {
IndexReader r = DirectoryReader.open(userindex);
Directory compIdx = newDirectory();
SpellChecker compareSP = new SpellCheckerMock(compIdx, new LevensteinDistance(), new SuggestWordFrequencyComparator());
addwords(r, compareSP, "field3");
String[] similar = compareSP.suggestSimilar("fvie", 2, r, "field3",
SuggestMode.SUGGEST_WHEN_NOT_IN_INDEX);
assertTrue(similar.length == 2);
//five and fvei have the same score, but different frequencies.
assertEquals("fvei", similar[0]);
assertEquals("five", similar[1]);
r.close();
if (!compareSP.isClosed())
compareSP.close();
compIdx.close();
}
public void testBogusField() throws Exception {
IndexReader r = DirectoryReader.open(userindex);
Directory compIdx = newDirectory();
SpellChecker compareSP = new SpellCheckerMock(compIdx, new LevensteinDistance(), new SuggestWordFrequencyComparator());
addwords(r, compareSP, "field3");
String[] similar = compareSP.suggestSimilar("fvie", 2, r,
"bogusFieldBogusField", SuggestMode.SUGGEST_WHEN_NOT_IN_INDEX);
assertEquals(0, similar.length);
r.close();
if (!compareSP.isClosed())
compareSP.close();
compIdx.close();
}
public void testSuggestModes() throws Exception {
IndexReader r = DirectoryReader.open(userindex);
spellChecker.clearIndex();
addwords(r, spellChecker, "field1");
{
String[] similar = spellChecker.suggestSimilar("eighty", 2, r, "field1",
SuggestMode.SUGGEST_WHEN_NOT_IN_INDEX);
assertEquals(1, similar.length);
assertEquals("eighty", similar[0]);
}
{
String[] similar = spellChecker.suggestSimilar("eight", 2, r, "field1",
SuggestMode.SUGGEST_WHEN_NOT_IN_INDEX);
assertEquals(1, similar.length);
assertEquals("eight", similar[0]);
}
{
String[] similar = spellChecker.suggestSimilar("eighty", 5, r, "field1",
SuggestMode.SUGGEST_MORE_POPULAR);
assertEquals(5, similar.length);
assertEquals("eight", similar[0]);
}
{
String[] similar = spellChecker.suggestSimilar("twenty", 5, r, "field1",
SuggestMode.SUGGEST_MORE_POPULAR);
assertEquals(1, similar.length);
assertEquals("twenty-one", similar[0]);
}
{
String[] similar = spellChecker.suggestSimilar("eight", 5, r, "field1",
SuggestMode.SUGGEST_MORE_POPULAR);
assertEquals(0, similar.length);
}
{
String[] similar = spellChecker.suggestSimilar("eighty", 5, r, "field1",
SuggestMode.SUGGEST_ALWAYS);
assertEquals(5, similar.length);
assertEquals("eight", similar[0]);
}
{
String[] similar = spellChecker.suggestSimilar("eight", 5, r, "field1",
SuggestMode.SUGGEST_ALWAYS);
assertEquals(5, similar.length);
assertEquals("eighty", similar[0]);
}
r.close();
}
private void checkCommonSuggestions(IndexReader r) throws IOException {
String[] similar = spellChecker.suggestSimilar("fvie", 2);
assertTrue(similar.length > 0);
assertEquals(similar[0], "five");
similar = spellChecker.suggestSimilar("five", 2);
if (similar.length > 0) {
assertFalse(similar[0].equals("five")); // don't suggest a word for itself
}
similar = spellChecker.suggestSimilar("fiv", 2);
assertTrue(similar.length > 0);
assertEquals(similar[0], "five");
similar = spellChecker.suggestSimilar("fives", 2);
assertTrue(similar.length > 0);
assertEquals(similar[0], "five");
assertTrue(similar.length > 0);
similar = spellChecker.suggestSimilar("fie", 2);
assertEquals(similar[0], "five");
// test restraint to a field
similar = spellChecker.suggestSimilar("tousand", 10, r, "field1",
SuggestMode.SUGGEST_WHEN_NOT_IN_INDEX);
assertEquals(0, similar.length); // there isn't the term thousand in the field field1
similar = spellChecker.suggestSimilar("tousand", 10, r, "field2",
SuggestMode.SUGGEST_WHEN_NOT_IN_INDEX);
assertEquals(1, similar.length); // there is the term thousand in the field field2
}
private void checkLevenshteinSuggestions(IndexReader r) throws IOException {
// test small word
String[] similar = spellChecker.suggestSimilar("fvie", 2);
assertEquals(1, similar.length);
assertEquals(similar[0], "five");
similar = spellChecker.suggestSimilar("five", 2);
assertEquals(1, similar.length);
assertEquals(similar[0], "nine"); // don't suggest a word for itself
similar = spellChecker.suggestSimilar("fiv", 2);
assertEquals(1, similar.length);
assertEquals(similar[0], "five");
similar = spellChecker.suggestSimilar("ive", 2);
assertEquals(2, similar.length);
assertEquals(similar[0], "five");
assertEquals(similar[1], "nine");
similar = spellChecker.suggestSimilar("fives", 2);
assertEquals(1, similar.length);
assertEquals(similar[0], "five");
similar = spellChecker.suggestSimilar("fie", 2);
assertEquals(2, similar.length);
assertEquals(similar[0], "five");
assertEquals(similar[1], "nine");
similar = spellChecker.suggestSimilar("fi", 2);
assertEquals(1, similar.length);
assertEquals(similar[0], "five");
// test restraint to a field
similar = spellChecker.suggestSimilar("tousand", 10, r, "field1",
SuggestMode.SUGGEST_WHEN_NOT_IN_INDEX);
assertEquals(0, similar.length); // there isn't the term thousand in the field field1
similar = spellChecker.suggestSimilar("tousand", 10, r, "field2",
SuggestMode.SUGGEST_WHEN_NOT_IN_INDEX);
assertEquals(1, similar.length); // there is the term thousand in the field field2
similar = spellChecker.suggestSimilar("onety", 2);
assertEquals(2, similar.length);
assertEquals(similar[0], "ninety");
assertEquals(similar[1], "one");
// should not throw exception
spellChecker.suggestSimilar("tousand", 10, r, null, SuggestMode.SUGGEST_WHEN_NOT_IN_INDEX);
}
private void checkJaroWinklerSuggestions() throws IOException {
String[] similar = spellChecker.suggestSimilar("onety", 2);
assertEquals(2, similar.length);
assertEquals(similar[0], "one");
assertEquals(similar[1], "ninety");
}
private void checkNGramSuggestions() throws IOException {
String[] similar = spellChecker.suggestSimilar("onety", 2);
assertEquals(2, similar.length);
assertEquals(similar[0], "one");
assertEquals(similar[1], "ninety");
}
private void addwords(IndexReader r, SpellChecker sc, String field) throws IOException {
long time = System.currentTimeMillis();
sc.indexDictionary(new LuceneDictionary(r, field), newIndexWriterConfig(null), false);
time = System.currentTimeMillis() - time;
//System.out.println("time to build " + field + ": " + time);
}
private int numdoc() throws IOException {
IndexReader rs = DirectoryReader.open(spellindex);
int num = rs.numDocs();
assertTrue(num != 0);
//System.out.println("num docs: " + num);
rs.close();
return num;
}
public void testClose() throws IOException {
IndexReader r = DirectoryReader.open(userindex);
spellChecker.clearIndex();
String field = "field1";
addwords(r, spellChecker, "field1");
int num_field1 = this.numdoc();
addwords(r, spellChecker, "field2");
int num_field2 = this.numdoc();
assertEquals(num_field2, num_field1 + 1);
checkCommonSuggestions(r);
assertLastSearcherOpen(4);
spellChecker.close();
assertSearchersClosed();
expectThrows(AlreadyClosedException.class, () -> {
spellChecker.close();
});
expectThrows(AlreadyClosedException.class, () -> {
checkCommonSuggestions(r);
});
expectThrows(AlreadyClosedException.class, () -> {
spellChecker.clearIndex();
});
expectThrows(AlreadyClosedException.class, () -> {
spellChecker.indexDictionary(new LuceneDictionary(r, field), newIndexWriterConfig(null), false);
});
expectThrows(AlreadyClosedException.class, () -> {
spellChecker.setSpellIndex(spellindex);
});
assertEquals(4, searchers.size());
assertSearchersClosed();
r.close();
}
/*
* tests if the internally shared indexsearcher is correctly closed
* when the spellchecker is concurrently accessed and closed.
*/
public void testConcurrentAccess() throws IOException, InterruptedException {
assertEquals(1, searchers.size());
final IndexReader r = DirectoryReader.open(userindex);
spellChecker.clearIndex();
assertEquals(2, searchers.size());
addwords(r, spellChecker, "field1");
assertEquals(3, searchers.size());
int num_field1 = this.numdoc();
addwords(r, spellChecker, "field2");
assertEquals(4, searchers.size());
int num_field2 = this.numdoc();
assertEquals(num_field2, num_field1 + 1);
int numThreads = 5 + random().nextInt(5);
ExecutorService executor = Executors.newFixedThreadPool(numThreads, new NamedThreadFactory("testConcurrentAccess"));
SpellCheckWorker[] workers = new SpellCheckWorker[numThreads];
for (int i = 0; i < numThreads; i++) {
SpellCheckWorker spellCheckWorker = new SpellCheckWorker(r);
executor.execute(spellCheckWorker);
workers[i] = spellCheckWorker;
}
int iterations = 5 + random().nextInt(5);
for (int i = 0; i < iterations; i++) {
Thread.sleep(100);
// concurrently reset the spell index
spellChecker.setSpellIndex(this.spellindex);
// for debug - prints the internal open searchers
// showSearchersOpen();
}
spellChecker.close();
executor.shutdown();
// wait for 60 seconds - usually this is very fast but coverage runs could take quite long
executor.awaitTermination(60L, TimeUnit.SECONDS);
for (int i = 0; i < workers.length; i++) {
assertFalse(String.format(Locale.ROOT, "worker thread %d failed", i), workers[i].failed);
assertTrue(String.format(Locale.ROOT, "worker thread %d is still running but should be terminated", i), workers[i].terminated);
}
// 4 searchers more than iterations
// 1. at creation
// 2. clearIndex()
// 2. and 3. during addwords
assertEquals(iterations + 4, searchers.size());
assertSearchersClosed();
r.close();
}
private void assertLastSearcherOpen(int numSearchers) {
assertEquals(numSearchers, searchers.size());
IndexSearcher[] searcherArray = searchers.toArray(new IndexSearcher[0]);
for (int i = 0; i < searcherArray.length; i++) {
if (i == searcherArray.length - 1) {
assertTrue("expected last searcher open but was closed",
searcherArray[i].getIndexReader().getRefCount() > 0);
} else {
assertFalse("expected closed searcher but was open - Index: " + i,
searcherArray[i].getIndexReader().getRefCount() > 0);
}
}
}
private void assertSearchersClosed() {
for (IndexSearcher searcher : searchers) {
assertEquals(0, searcher.getIndexReader().getRefCount());
}
}
// For debug
// private void showSearchersOpen() {
// int count = 0;
// for (IndexSearcher searcher : searchers) {
// if(searcher.getIndexReader().getRefCount() > 0)
// ++count;
// }
// System.out.println(count);
// }
private class SpellCheckWorker implements Runnable {
private final IndexReader reader;
volatile boolean terminated = false;
volatile boolean failed = false;
SpellCheckWorker(IndexReader reader) {
super();
this.reader = reader;
}
@Override
public void run() {
try {
while (true) {
try {
checkCommonSuggestions(reader);
} catch (AlreadyClosedException e) {
return;
} catch (Throwable e) {
e.printStackTrace();
failed = true;
return;
}
}
} finally {
terminated = true;
}
}
}
class SpellCheckerMock extends SpellChecker {
public SpellCheckerMock(Directory spellIndex) throws IOException {
super(spellIndex);
}
public SpellCheckerMock(Directory spellIndex, StringDistance sd)
throws IOException {
super(spellIndex, sd);
}
public SpellCheckerMock(Directory spellIndex, StringDistance sd, Comparator<SuggestWord> comparator) throws IOException {
super(spellIndex, sd, comparator);
}
@Override
IndexSearcher createSearcher(Directory dir) throws IOException {
IndexSearcher searcher = super.createSearcher(dir);
TestSpellChecker.this.searchers.add(searcher);
return searcher;
}
}
}