Java Code Examples for org.apache.lucene.index.DirectoryReader

private void verify(Object... shapes) throws Exception {
  IndexWriterConfig iwc = newIndexWriterConfig();
  iwc.setMergeScheduler(new SerialMergeScheduler());
  int mbd = iwc.getMaxBufferedDocs();
  if (mbd != -1 && mbd < shapes.length / 100) {
    iwc.setMaxBufferedDocs(shapes.length / 100);
  }
  Directory dir;
  if (shapes.length > 1000) {
    dir = newFSDirectory(createTempDir(getClass().getSimpleName()));
  } else {
    dir = newDirectory();
  }
  IndexWriter w = new IndexWriter(dir, iwc);

  // index random polygons
  indexRandomShapes(w, shapes);

  // query testing
  final IndexReader reader = DirectoryReader.open(w);
  // test random bbox queries
  verifyRandomQueries(reader, shapes);
  IOUtils.close(w, reader, dir);
}
 

public RetrievalAppQueryExpansion(String retrievalParamFile){
    System.out.println("Retrieval App");
    readParamsFromFile(retrievalParamFile);
    try {
        reader = DirectoryReader.open(FSDirectory.open(new File(p.indexName).toPath()));
        searcher = new IndexSearcher(reader);

        // Create similarity function and parameter
        selectSimilarityFunction(sim);
        searcher.setSimilarity(simfn);

        // Use whatever ANALYZER you want
        analyzer = new StandardAnalyzer();

        parser = new QueryParser("content", analyzer);

    } catch (Exception e){
        System.out.println(" caught a " + e.getClass() + "\n with message: " + e.getMessage());
    }

}
 

@Test
public void testHighCardinalityRatioReturnsTrueForHighCardinality() throws Exception {
    IndexWriter iw = new IndexWriter(new ByteBuffersDirectory(), new IndexWriterConfig(new StandardAnalyzer()));
    String columnName = "x";
    for (int i = 0; i < 10; i++) {
        Document doc = new Document();
        BytesRef value = new BytesRef(Integer.toString(i));
        doc.add(new Field(columnName, value, KeywordFieldMapper.Defaults.FIELD_TYPE.clone()));
        iw.addDocument(doc);
    }
    iw.commit();

    IndexSearcher indexSearcher = new IndexSearcher(DirectoryReader.open(iw));

    assertThat(
        GroupByOptimizedIterator.hasHighCardinalityRatio(() -> new Engine.Searcher("dummy", indexSearcher, () -> {}), "x"),
        is(true)
    );
}
 

public void testSimple() throws Exception {
  Directory dir = newDirectory();
  IndexWriterConfig iwc = newIndexWriterConfig().setMergePolicy(NoMergePolicy.INSTANCE);
  RandomIndexWriter w = new RandomIndexWriter(random(), dir, iwc);
  w.addDocument(new Document());
  DirectoryReader reader = w.getReader();

  QueryBitSetProducer producer = new QueryBitSetProducer(new MatchNoDocsQuery());
  assertNull(producer.getBitSet(reader.leaves().get(0)));
  assertEquals(1, producer.cache.size());

  producer = new QueryBitSetProducer(new MatchAllDocsQuery());
  BitSet bitSet = producer.getBitSet(reader.leaves().get(0));
  assertEquals(1, bitSet.length());
  assertEquals(true, bitSet.get(0));
  assertEquals(1, producer.cache.size());

  IOUtils.close(reader, w, dir);
}
 

public void testPullOneTermsEnum() throws Exception {
  Directory dir = newDirectory();
  RandomIndexWriter w = new RandomIndexWriter(random(), dir);
  Document doc = new Document();
  doc.add(new StringField("foo", "1", Store.NO));
  w.addDocument(doc);
  DirectoryReader reader = w.getReader();
  w.close();
  final AtomicInteger counter = new AtomicInteger();
  DirectoryReader wrapped = new TermsCountingDirectoryReaderWrapper(reader, counter);

  final List<BytesRef> terms = new ArrayList<>();
  // enough terms to avoid the rewrite
  final int numTerms = TestUtil.nextInt(random(), TermInSetQuery.BOOLEAN_REWRITE_TERM_COUNT_THRESHOLD + 1, 100);
  for (int i = 0; i < numTerms; ++i) {
    final BytesRef term = new BytesRef(RandomStrings.randomUnicodeOfCodepointLength(random(), 10));
    terms.add(term);
  }

  assertEquals(0, new IndexSearcher(wrapped).count(new TermInSetQuery("bar", terms)));
  assertEquals(0, counter.get()); // missing field
  new IndexSearcher(wrapped).count(new TermInSetQuery("foo", terms));
  assertEquals(1, counter.get());
  wrapped.close();
  dir.close();
}
 

public List<Document> searchIndex(String inField, String queryString) {
    try {
        Query query = new QueryParser(inField, analyzer).parse(queryString);

        IndexReader indexReader = DirectoryReader.open(memoryIndex);
        IndexSearcher searcher = new IndexSearcher(indexReader);
        TopDocs topDocs = searcher.search(query, 10);
        List<Document> documents = new ArrayList<>();
        for (ScoreDoc scoreDoc : topDocs.scoreDocs) {
            documents.add(searcher.doc(scoreDoc.doc));
        }

        return documents;
    } catch (IOException | ParseException e) {
        e.printStackTrace();
    }
    return null;

}
 

/**
	 * 初始化indexSearch对象的方法
	 * @throws Exception
	 */
	public void createIndexSearch(){
		try{
			IndexReader indexReader = DirectoryReader.open(this.indexSettings.directory);
			this.indexSearcher = new IndexSearcher(indexReader);
			//输出现在的索引
//	        for(int i =0; i<indexReader.numDocs();i++){
//	        	System.out.println(indexReader.document(i));
//	        	System.out.println("文件名称："+indexReader.document(i).get("fileName")+"\t文件描述:"+indexReader.document(i).get("fileDesc")+"\t文件ID："+indexReader.document(i).get("fileId")+"\t创建者："+indexReader.document(i).get("fileCreator"));
//	        }
//	        System.out.println("索引版本:" + indexReader.getCoreCacheKey());
//	    	System.out.println("索引内文档数量："+indexReader.numDocs());
		}catch(Exception e){
			e.printStackTrace();
		}
	}
 

public void testIndexSortOptimizationDeactivated(RandomIndexWriter writer) throws IOException {
  DirectoryReader reader = writer.getReader();
  IndexSearcher searcher = newSearcher(reader);

  Query query = createQuery("field", 0, 0);
  Weight weight = query.createWeight(searcher, ScoreMode.TOP_SCORES, 1.0F);

  // Check that the two-phase iterator is not null, indicating that we've fallen
  // back to SortedNumericDocValuesField.newSlowRangeQuery.
  for (LeafReaderContext context : searcher.getIndexReader().leaves()) {
    Scorer scorer = weight.scorer(context);
    assertNotNull(scorer.twoPhaseIterator());
  }

  reader.close();
}
 

public DummyDirectoryReader(DirectoryReader in) throws IOException {
  super(in, new SubReaderWrapper() {
    @Override
    public LeafReader wrap(LeafReader reader) {
      return new FilterLeafReader(reader) {
        @Override
        public CacheHelper getCoreCacheHelper() {
          return null;
        }
        @Override
        public CacheHelper getReaderCacheHelper() {
          return null;
        }
      };
    }
  });
}
 

public static SimpleOrderedMap<Object> getIndexInfo(DirectoryReader reader) throws IOException {
  Directory dir = reader.directory();
  SimpleOrderedMap<Object> indexInfo = new SimpleOrderedMap<>();

  indexInfo.add("numDocs", reader.numDocs());
  indexInfo.add("maxDoc", reader.maxDoc());
  indexInfo.add("deletedDocs", reader.maxDoc() - reader.numDocs());
  indexInfo.add("indexHeapUsageBytes", getIndexHeapUsed(reader));

  indexInfo.add("version", reader.getVersion());  // TODO? Is this different then: IndexReader.getCurrentVersion( dir )?
  indexInfo.add("segmentCount", reader.leaves().size());
  indexInfo.add("current", closeSafe( reader::isCurrent));
  indexInfo.add("hasDeletions", reader.hasDeletions() );
  indexInfo.add("directory", dir );
  IndexCommit indexCommit = reader.getIndexCommit();
  String segmentsFileName = indexCommit.getSegmentsFileName();
  indexInfo.add("segmentsFile", segmentsFileName);
  indexInfo.add("segmentsFileSizeInBytes", getSegmentsFileLength(indexCommit));
  Map<String,String> userData = indexCommit.getUserData();
  indexInfo.add("userData", userData);
  String s = userData.get(SolrIndexWriter.COMMIT_TIME_MSEC_KEY);
  if (s != null) {
    indexInfo.add("lastModified", new Date(Long.parseLong(s)));
  }
  return indexInfo;
}
 

@Test
public void testEmptyRegexContextQuery() throws Exception {
  Analyzer analyzer = new MockAnalyzer(random());
  RandomIndexWriter iw = new RandomIndexWriter(random(), dir, iwcWithSuggestField(analyzer, "suggest_field"));
  Document document = new Document();
  document.add(new ContextSuggestField("suggest_field", "suggestion", 1, "type"));
  iw.addDocument(document);

  if (rarely()) {
    iw.commit();
  }

  DirectoryReader reader = iw.getReader();
  SuggestIndexSearcher suggestIndexSearcher = new SuggestIndexSearcher(reader);
  ContextQuery query = new ContextQuery(new RegexCompletionQuery(new Term("suggest_field", "")));
  query.addContext("type", 1);

  TopSuggestDocs suggest = suggestIndexSearcher.suggest(query, 5, false);
  assertEquals(0, suggest.scoreDocs.length);

  reader.close();
  iw.close();
}
 

public void testReaderNotSuitedForCaching() throws IOException{
  Directory dir = newDirectory();
  IndexWriterConfig iwc = newIndexWriterConfig().setMergePolicy(NoMergePolicy.INSTANCE);
  RandomIndexWriter w = new RandomIndexWriter(random(), dir, iwc);
  w.addDocument(new Document());
  DirectoryReader reader = new DummyDirectoryReader(w.getReader());

  QueryBitSetProducer producer = new QueryBitSetProducer(new MatchNoDocsQuery());
  assertNull(producer.getBitSet(reader.leaves().get(0)));
  assertEquals(0, producer.cache.size());

  producer = new QueryBitSetProducer(new MatchAllDocsQuery());
  BitSet bitSet = producer.getBitSet(reader.leaves().get(0));
  assertEquals(1, bitSet.length());
  assertEquals(true, bitSet.get(0));
  assertEquals(0, producer.cache.size());

  IOUtils.close(reader, w, dir);
}
 

/** Returns the sum of RAM bytes used by each segment */
private static long getIndexHeapUsed(DirectoryReader reader) {
  return reader.leaves().stream()
      .map(LeafReaderContext::reader)
      .map(FilterLeafReader::unwrap)
      .map(leafReader -> {
        if (leafReader instanceof Accountable) {
          return ((Accountable) leafReader).ramBytesUsed();
        } else {
          return -1L; // unsupported
        }
      })
      .mapToLong(Long::longValue)
      .reduce(0, (left, right) -> left == -1 || right == -1 ? -1 : left + right);
  // if any leaves are unsupported (-1), we ultimately return -1.
}
 

@Test
public void testEmptyRegexQuery() throws Exception {
  Analyzer analyzer = new MockAnalyzer(random());
  RandomIndexWriter iw = new RandomIndexWriter(random(), dir, iwcWithSuggestField(analyzer, "suggest_field"));
  Document document = new Document();
  document.add(new SuggestField("suggest_field", "suggestion1", 1));
  iw.addDocument(document);

  if (rarely()) {
    iw.commit();
  }

  DirectoryReader reader = iw.getReader();
  SuggestIndexSearcher suggestIndexSearcher = new SuggestIndexSearcher(reader);
  RegexCompletionQuery query = new RegexCompletionQuery(new Term("suggest_field", ""));

  TopSuggestDocs suggest = suggestIndexSearcher.suggest(query, 5, false);
  assertEquals(0, suggest.scoreDocs.length);

  reader.close();
  iw.close();
}
 

public void testMinShouldMatchLeniency() throws Exception {
  Directory dir = newDirectory();
  IndexWriter w = new IndexWriter(dir, newIndexWriterConfig(new MockAnalyzer(random())));
  Document doc = new Document();
  doc.add(newTextField("field", "a b c d", Field.Store.NO));
  w.addDocument(doc);
  IndexReader r = DirectoryReader.open(w);
  IndexSearcher s = newSearcher(r);
  BooleanQuery.Builder bq = new BooleanQuery.Builder();
  bq.add(new TermQuery(new Term("field", "a")), BooleanClause.Occur.SHOULD);
  bq.add(new TermQuery(new Term("field", "b")), BooleanClause.Occur.SHOULD);

  // No doc can match: BQ has only 2 clauses and we are asking for minShouldMatch=4
  bq.setMinimumNumberShouldMatch(4);
  assertEquals(0, s.search(bq.build(), 1).totalHits.value);
  r.close();
  w.close();
  dir.close();
}
 

@Test
public void testDeleteRecord() throws IOException {
  RAMDirectory directory = new RAMDirectory();
  DirectoryReader reader = getIndexReader(directory);
  IndexWriter writer = new IndexWriter(directory, _conf.clone());
  assertEquals(0, reader.numDocs());

  Row row = genRow();
  List<Column> cols = new ArrayList<Column>();
  cols.add(new Column("n", "v"));
  row.addToRecords(new Record("1", "fam", cols));

  _action.replaceRow(row);
  _action.performMutate(getSearcher(reader, directory), writer);
  reader = commitAndReopen(reader, writer);
  assertEquals(2, reader.numDocs());

  _action.deleteRecord(row.getId(), "1");
  _action.performMutate(getSearcher(reader, directory), writer);
  reader = commitAndReopen(reader, writer);
  assertEquals(1, reader.numDocs());
}
 

public void testPositionIncrements() throws Exception {
  Directory dir = newDirectory();
  Analyzer a = new MockAnalyzer(random(), MockTokenizer.SIMPLE, true, MockTokenFilter.ENGLISH_STOPSET);
  IndexWriter w = new IndexWriter(dir, newIndexWriterConfig(a));
  Document doc = new Document();
  doc.add(newTextField("field", "the wizard of ozzy", Field.Store.NO));
  w.addDocument(doc);
  IndexReader r = DirectoryReader.open(w);
  w.close();
  IndexSearcher s = newSearcher(r);
  
  Query q = getQuery("\"wizard of ozzy\"",a);
  assertEquals(1, s.search(q, 1).totalHits.value);
  r.close();
  dir.close();
}
 

@Test
public void testDocValuesFormat() throws IOException {
  RAMDirectory directory = new RAMDirectory();
  IndexWriterConfig conf = new IndexWriterConfig(Version.LUCENE_43, new WhitespaceAnalyzer(Version.LUCENE_43));
  conf.setCodec(new Blur024Codec());
  IndexWriter writer = new IndexWriter(directory, conf);

  Document doc = new Document();
  doc.add(new StringField("f", "v", Store.YES));
  doc.add(new SortedDocValuesField("f", new BytesRef("v")));
  writer.addDocument(doc);

  writer.close();

  DirectoryReader reader = DirectoryReader.open(directory);
  AtomicReaderContext context = reader.leaves().get(0);
  AtomicReader atomicReader = context.reader();
  SortedDocValues sortedDocValues = atomicReader.getSortedDocValues("f");
  assertTrue(sortedDocValues.getClass().getName().startsWith(DiskDocValuesProducer.class.getName()));

  reader.close();
}
 

public TopDocs executeQuery(org.apache.lucene.search.Query query) throws IOException, ParseException {
	Directory indexDir = FSDirectory.open(Paths.get(INDEX_DIRECTORY));
	try {
		IndexReader reader = DirectoryReader.open(indexDir);
		IndexSearcher searcher = new IndexSearcher(reader);
		if (isBm25 == false) {
			ClassicSimilarity CS = new ClassicSimilarity();
			searcher.setSimilarity(CS);
		}
		TopDocs docs = searcher.search(query, hitsPerPage);
		return docs;
	} catch (Exception e) {
		logger.error(e.getMessage());
		return null;
	}
}
 

/**
 * Sets up a RAM-resident Directory, and adds documents (using English.intToEnglish()) with two fields: field and multiField
 * and analyzes them using the PayloadAnalyzer
 * @param similarity The Similarity class to use in the Searcher
 * @param numDocs The num docs to add
 * @return An IndexSearcher
 */
// TODO: randomize
public IndexSearcher setUp(Random random, Similarity similarity, int numDocs) throws IOException {
  Directory directory = new MockDirectoryWrapper(random, new ByteBuffersDirectory());
  PayloadAnalyzer analyzer = new PayloadAnalyzer();

  // TODO randomize this
  IndexWriter writer = new IndexWriter(directory, new IndexWriterConfig(
      analyzer).setSimilarity(similarity));
  // writer.infoStream = System.out;
  for (int i = 0; i < numDocs; i++) {
    Document doc = new Document();
    doc.add(new TextField(FIELD, English.intToEnglish(i), Field.Store.YES));
    doc.add(new TextField(MULTI_FIELD, English.intToEnglish(i) + "  " + English.intToEnglish(i), Field.Store.YES));
    doc.add(new TextField(NO_PAYLOAD_FIELD, English.intToEnglish(i), Field.Store.YES));
    writer.addDocument(doc);
  }
  writer.forceMerge(1);
  reader = DirectoryReader.open(writer);
  writer.close();

  IndexSearcher searcher = LuceneTestCase.newSearcher(LuceneTestCase.getOnlyLeafReader(reader));
  searcher.setSimilarity(similarity);
  return searcher;
}
 

/** User drills down on 'tags/solr'. */
private FacetResult drillDown() throws IOException {
  DirectoryReader indexReader = DirectoryReader.open(indexDir);
  IndexSearcher searcher = new IndexSearcher(indexReader);
  TaxonomyReader taxoReader = new DirectoryTaxonomyReader(taxoDir);

  // Passing no baseQuery means we drill down on all
  // documents ("browse only"):
  DrillDownQuery q = new DrillDownQuery(config);

  // Now user drills down on Publish Date/2010:
  q.add("tags", "solr");
  FacetsCollector fc = new FacetsCollector();
  FacetsCollector.search(searcher, q, 10, fc);

  // Retrieve results
  Facets facets = new TaxonomyFacetSumFloatAssociations("$genre", taxoReader, config, fc);
  FacetResult result = facets.getTopChildren(10, "genre");

  indexReader.close();
  taxoReader.close();
  
  return result;
}
 

public void testReqOptPropagatesApproximations() throws IOException {
  Directory dir = newDirectory();
  RandomIndexWriter w = new RandomIndexWriter(random(), dir);
  Document doc = new Document();
  Field f = newTextField("field", "a b c", Field.Store.NO);
  doc.add(f);
  w.addDocument(doc);
  w.commit();

  DirectoryReader reader = w.getReader();
  final IndexSearcher searcher = new IndexSearcher(reader);
  searcher.setQueryCache(null); // to still have approximations

  PhraseQuery pq = new PhraseQuery("field", "a", "b");

  BooleanQuery.Builder q = new BooleanQuery.Builder();
  q.add(pq, Occur.MUST);
  q.add(new TermQuery(new Term("field", "c")), Occur.SHOULD);

  final Weight weight = searcher.createWeight(searcher.rewrite(q.build()), ScoreMode.COMPLETE, 1);
  final Scorer scorer = weight.scorer(reader.leaves().get(0));
  assertTrue(scorer instanceof ReqOptSumScorer);
  assertNotNull(scorer.twoPhaseIterator());

  reader.close();
  w.close();
  dir.close();
}
 

public void testOneClauseRewriteOptimization() throws Exception {
  final String FIELD = "content";
  final String VALUE = "foo";

  Directory dir = newDirectory();
  (new RandomIndexWriter(random(), dir)).close();
  IndexReader r = DirectoryReader.open(dir);

  TermQuery expected = new TermQuery(new Term(FIELD, VALUE));

  final int numLayers = atLeast(3);
  Query actual = new TermQuery(new Term(FIELD, VALUE));

  for (int i = 0; i < numLayers; i++) {

    BooleanQuery.Builder bq = new BooleanQuery.Builder();
    bq.add(actual, random().nextBoolean()
           ? BooleanClause.Occur.SHOULD : BooleanClause.Occur.MUST);
    actual = bq.build();
  }

  assertEquals(numLayers + ": " + actual.toString(),
               expected, new IndexSearcher(r).rewrite(actual));

  r.close();
  dir.close();
}
 

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 testFILTERClauseBehavesLikeMUST() throws IOException {
  Directory dir = newDirectory();
  RandomIndexWriter w = new RandomIndexWriter(random(), dir);
  Document doc = new Document();
  Field f = newTextField("field", "a b c d", Field.Store.NO);
  doc.add(f);
  w.addDocument(doc);
  f.setStringValue("b d");
  w.addDocument(doc);
  f.setStringValue("d");
  w.addDocument(doc);
  w.commit();

  DirectoryReader reader = w.getReader();
  final IndexSearcher searcher = new IndexSearcher(reader);

  for (List<String> requiredTerms : Arrays.<List<String>>asList(
      Arrays.asList("a", "d"),
      Arrays.asList("a", "b", "d"),
      Arrays.asList("d"),
      Arrays.asList("e"),
      Arrays.asList())) {
    final BooleanQuery.Builder bq1 = new BooleanQuery.Builder();
    final BooleanQuery.Builder bq2 = new BooleanQuery.Builder();
    for (String term : requiredTerms) {
      final Query q = new TermQuery(new Term("field", term));
      bq1.add(q, Occur.MUST);
      bq2.add(q, Occur.FILTER);
    }

    final BitSet matches1 = getMatches(searcher, bq1.build());
    final BitSet matches2 = getMatches(searcher, bq2.build());
    assertEquals(matches1, matches2);
  }

  reader.close();
  w.close();
  dir.close();
}
 

public void testFieldCacheReuseAfterReopen() throws Exception {
  Directory dir = newDirectory();
  IndexWriter writer = new IndexWriter(
      dir,
      newIndexWriterConfig(new MockAnalyzer(random())).
          setMergePolicy(newLogMergePolicy(10))
  );
  Document doc = new Document();
  doc.add(new IntPoint("number", 17));
  writer.addDocument(doc);
  writer.commit();

  // Open reader1
  DirectoryReader r = DirectoryReader.open(dir);
  LeafReader r1 = getOnlyLeafReader(r);
  final NumericDocValues ints = FieldCache.DEFAULT.getNumerics(r1, "number", FieldCache.INT_POINT_PARSER);
  assertEquals(0, ints.nextDoc());
  assertEquals(17, ints.longValue());

  // Add new segment
  writer.addDocument(doc);
  writer.commit();

  // Reopen reader1 --> reader2
  DirectoryReader r2 = DirectoryReader.openIfChanged(r);
  assertNotNull(r2);
  r.close();
  LeafReader sub0 = r2.leaves().get(0).reader();
  final NumericDocValues ints2 = FieldCache.DEFAULT.getNumerics(sub0, "number", FieldCache.INT_POINT_PARSER);
  r2.close();
  assertEquals(0, ints2.nextDoc());
  assertEquals(17, ints2.longValue());

  writer.close();
  dir.close();
}
 

public Searcher(String indexDirectoryPath) throws GerbilException {

		try {
			indexDirectory = FSDirectory.open(new File(
					indexDirectoryPath).toPath());
			indexReader = DirectoryReader.open(indexDirectory);
			indexSearcher = new IndexSearcher(indexReader);
		} catch (IOException e) {
			throw new GerbilException("Could not initialize Searcher", ErrorTypes.UNEXPECTED_EXCEPTION);
		}
	}
 

/**
 * If there are configured {@link IndexSearcherWrapper} instances, the {@link IndexSearcher} of the provided engine searcher
 * gets wrapped and a new {@link Engine.Searcher} instances is returned, otherwise the provided {@link Engine.Searcher} is returned.
 *
 * This is invoked each time a {@link Engine.Searcher} is requested to do an operation. (for example search)
 */
public final Engine.Searcher wrap(Engine.Searcher engineSearcher) throws IOException {
    final ElasticsearchDirectoryReader elasticsearchDirectoryReader = ElasticsearchDirectoryReader.getElasticsearchDirectoryReader(engineSearcher.getDirectoryReader());
    if (elasticsearchDirectoryReader == null) {
        throw new IllegalStateException("Can't wrap non elasticsearch directory reader");
    }
    NonClosingReaderWrapper nonClosingReaderWrapper = new NonClosingReaderWrapper(engineSearcher.getDirectoryReader());
    DirectoryReader reader = wrap(nonClosingReaderWrapper);
    if (reader != nonClosingReaderWrapper) {
        if (reader.getReaderCacheHelper() != elasticsearchDirectoryReader.getReaderCacheHelper()) {
            throw new IllegalStateException("wrapped directory reader doesn't delegate IndexReader#getCoreCacheKey, wrappers must override this method and delegate" +
                    " to the original readers core cache key. Wrapped readers can't be used as cache keys since their are used only per request which would lead to subtle bugs");
        }
        if (ElasticsearchDirectoryReader.getElasticsearchDirectoryReader(reader) != elasticsearchDirectoryReader) {
            // prevent that somebody wraps with a non-filter reader
            throw new IllegalStateException("wrapped directory reader hides actual ElasticsearchDirectoryReader but shouldn't");
        }
    }

    final IndexSearcher origIndexSearcher = engineSearcher.searcher();
    final IndexSearcher innerIndexSearcher = new IndexSearcher(reader);
    innerIndexSearcher.setQueryCache(origIndexSearcher.getQueryCache());
    innerIndexSearcher.setQueryCachingPolicy(origIndexSearcher.getQueryCachingPolicy());
    innerIndexSearcher.setSimilarity(origIndexSearcher.getSimilarity());
    // TODO: Right now IndexSearcher isn't wrapper friendly, when it becomes wrapper friendly we should revise this extension point
    // For example if IndexSearcher#rewrite() is overwritten than also IndexSearcher#createNormalizedWeight needs to be overwritten
    // This needs to be fixed before we can allow the IndexSearcher from Engine to be wrapped multiple times
    final IndexSearcher indexSearcher = wrap(innerIndexSearcher);
    if (reader == nonClosingReaderWrapper && indexSearcher == innerIndexSearcher) {
        return engineSearcher;
    } else {
        // we close the reader to make sure wrappers can release resources if needed....
        // our NonClosingReaderWrapper makes sure that our reader is not closed
        return new Engine.Searcher(engineSearcher.source(), indexSearcher, () ->
            IOUtils.close(indexSearcher.getIndexReader(), // this will close the wrappers excluding the NonClosingReaderWrapper
            engineSearcher)); // this will run the closeable on the wrapped engine searcher
    }
}
 

private MergeSortRowIdMatcher getMergeSortRowIdMatcher(Text rowId,
    Reducer<Text, NullWritable, Text, BooleanWritable>.Context context) throws IOException {
  BlurPartitioner blurPartitioner = new BlurPartitioner();
  int shard = blurPartitioner.getShard(rowId, _numberOfShardsInTable);
  String shardName = ShardUtil.getShardName(shard);

  Path shardPath = new Path(_tablePath, shardName);
  HdfsDirectory hdfsDirectory = new HdfsDirectory(_configuration, shardPath);
  SnapshotIndexDeletionPolicy policy = new SnapshotIndexDeletionPolicy(_configuration,
      SnapshotIndexDeletionPolicy.getGenerationsPath(shardPath));
  Long generation = policy.getGeneration(_snapshot);
  if (generation == null) {
    hdfsDirectory.close();
    throw new IOException("Snapshot [" + _snapshot + "] not found in shard [" + shardPath + "]");
  }

  BlurConfiguration bc = new BlurConfiguration();
  BlockCacheDirectoryFactoryV2 blockCacheDirectoryFactoryV2 = new BlockCacheDirectoryFactoryV2(bc,
      _totalNumberOfBytes);
  _closer.register(blockCacheDirectoryFactoryV2);
  Directory dir = blockCacheDirectoryFactoryV2.newDirectory("table", "shard", hdfsDirectory, null);
  List<IndexCommit> listCommits = DirectoryReader.listCommits(dir);
  IndexCommit indexCommit = ExistingDataIndexLookupMapper.findIndexCommit(listCommits, generation, shardPath);
  DirectoryReader reader = DirectoryReader.open(indexCommit);
  _rowIdsFromIndex.setValue(getTotalNumberOfRowIds(reader));

  Path cachePath = MergeSortRowIdMatcher.getCachePath(_cachePath, _table, shardName);
  return new MergeSortRowIdMatcher(dir, generation, _configuration, cachePath, context);
}
 

private IndexSearcher getIndexSearcher() throws IOException {
    if (reader == null) {
        reader = DirectoryReader.open(directory);
    } else {
        DirectoryReader changeReader = DirectoryReader.openIfChanged(reader);
        if (changeReader != null) {
            reader.close();
            reader = changeReader;
        }
    }
    return new IndexSearcher(reader);
}