Examples with AbstractIterator com.google.common.collect.AbstractIterator used on opensource projects

Example 41 with AbstractIterator

use of com.google.common.collect.AbstractIterator in project jackrabbit-oak by apache.

the class Segment method readReferencedSegments.

private SegmentReferences readReferencedSegments(final SegmentIdProvider idProvider) {
    checkState(getReferencedSegmentIdCount() + 1 < 0xffff, "Segment cannot have more than 0xffff references");
    final int referencedSegmentIdCount = getReferencedSegmentIdCount();
    // We need to keep SegmentId references (as opposed to e.g. UUIDs)
    // here as frequently resolving the segment ids via the segment id
    // tables is prohibitively expensive.
    // These SegmentId references are not a problem wrt. heap usage as
    // their individual memoised references to their underlying segment
    // is managed via the SegmentCache. It is the size of that cache that
    // keeps overall heap usage by Segment instances bounded.
    // See OAK-6106.
    final SegmentId[] refIds = new SegmentId[referencedSegmentIdCount];
    return new SegmentReferences() {

        @Override
        public SegmentId getSegmentId(int reference) {
            checkArgument(reference <= referencedSegmentIdCount, "Segment reference out of bounds");
            SegmentId id = refIds[reference - 1];
            if (id == null) {
                synchronized (refIds) {
                    id = refIds[reference - 1];
                    if (id == null) {
                        long msb = data.getSegmentReferenceMsb(reference - 1);
                        long lsb = data.getSegmentReferenceLsb(reference - 1);
                        id = idProvider.newSegmentId(msb, lsb);
                        refIds[reference - 1] = id;
                    }
                }
            }
            return id;
        }

        @Nonnull
        @Override
        public Iterator<SegmentId> iterator() {
            return new AbstractIterator<SegmentId>() {

                private int reference = 1;

                @Override
                protected SegmentId computeNext() {
                    if (reference <= referencedSegmentIdCount) {
                        return getSegmentId(reference++);
                    } else {
                        return endOfData();
                    }
                }
            };
        }
    };
}

Example 42 with AbstractIterator

use of com.google.common.collect.AbstractIterator in project jackrabbit-oak by apache.

the class Utils method internalGetSelectedDocuments.

private static Iterable<NodeDocument> internalGetSelectedDocuments(final DocumentStore store, final String indexedProperty, final long startValue, final int batchSize) {
    if (batchSize < 2) {
        throw new IllegalArgumentException("batchSize must be > 1");
    }
    return new Iterable<NodeDocument>() {

        @Override
        public Iterator<NodeDocument> iterator() {
            return new AbstractIterator<NodeDocument>() {

                private String startId = NodeDocument.MIN_ID_VALUE;

                private Iterator<NodeDocument> batch = nextBatch();

                @Override
                protected NodeDocument computeNext() {
                    // read next batch if necessary
                    if (!batch.hasNext()) {
                        batch = nextBatch();
                    }
                    NodeDocument doc;
                    if (batch.hasNext()) {
                        doc = batch.next();
                        // remember current id
                        startId = doc.getId();
                    } else {
                        doc = endOfData();
                    }
                    return doc;
                }

                private Iterator<NodeDocument> nextBatch() {
                    List<NodeDocument> result = indexedProperty == null ? store.query(Collection.NODES, startId, NodeDocument.MAX_ID_VALUE, batchSize) : store.query(Collection.NODES, startId, NodeDocument.MAX_ID_VALUE, indexedProperty, startValue, batchSize);
                    return result.iterator();
                }
            };
        }
    };
}

Example 43 with AbstractIterator

use of com.google.common.collect.AbstractIterator in project jackrabbit-oak by apache.

the class VersionGarbageCollectorIT method cancelGCAfterFirstPhase.

@Test
public void cancelGCAfterFirstPhase() throws Exception {
    createTestNode("foo");
    NodeBuilder builder = store.getRoot().builder();
    builder.child("foo").child("bar");
    merge(store, builder);
    builder = store.getRoot().builder();
    builder.child("foo").remove();
    merge(store, builder);
    store.runBackgroundOperations();
    clock.waitUntil(clock.getTime() + TimeUnit.HOURS.toMillis(1));
    final AtomicReference<VersionGarbageCollector> gcRef = Atomics.newReference();
    VersionGCSupport gcSupport = new VersionGCSupport(store.getDocumentStore()) {

        @Override
        public Iterable<NodeDocument> getPossiblyDeletedDocs(final long fromModified, final long toModified) {
            return new Iterable<NodeDocument>() {

                @Nonnull
                @Override
                public Iterator<NodeDocument> iterator() {
                    return new AbstractIterator<NodeDocument>() {

                        private Iterator<NodeDocument> it = candidates(fromModified, toModified);

                        @Override
                        protected NodeDocument computeNext() {
                            if (it.hasNext()) {
                                return it.next();
                            }
                            // cancel when we reach the end
                            gcRef.get().cancel();
                            return endOfData();
                        }
                    };
                }
            };
        }

        private Iterator<NodeDocument> candidates(long prevLastModifiedTime, long lastModifiedTime) {
            return super.getPossiblyDeletedDocs(prevLastModifiedTime, lastModifiedTime).iterator();
        }
    };
    gcRef.set(new VersionGarbageCollector(store, gcSupport));
    VersionGCStats stats = gcRef.get().gc(30, TimeUnit.MINUTES);
    assertTrue(stats.canceled);
    assertEquals(0, stats.deletedDocGCCount);
    assertEquals(0, stats.deletedLeafDocGCCount);
    assertEquals(0, stats.intermediateSplitDocGCCount);
    assertEquals(0, stats.splitDocGCCount);
}

Example 44 with AbstractIterator

use of com.google.common.collect.AbstractIterator in project jackrabbit-oak by apache.

the class LuceneIndex method query.

@Override
public Cursor query(final IndexPlan plan, NodeState rootState) {
    final Filter filter = plan.getFilter();
    FullTextExpression ft = filter.getFullTextConstraint();
    final Set<String> relPaths = getRelativePaths(ft);
    if (relPaths.size() > 1) {
        return new MultiLuceneIndex(filter, rootState, relPaths).query();
    }
    final String parent = relPaths.size() == 0 ? "" : relPaths.iterator().next();
    // we only restrict non-full-text conditions if there is
    // no relative property in the full-text constraint
    final boolean nonFullTextConstraints = parent.isEmpty();
    final int parentDepth = getDepth(parent);
    QueryLimits settings = filter.getQueryLimits();
    Iterator<LuceneResultRow> itr = new AbstractIterator<LuceneResultRow>() {

        private final Deque<LuceneResultRow> queue = Queues.newArrayDeque();

        private final Set<String> seenPaths = Sets.newHashSet();

        private ScoreDoc lastDoc;

        private int nextBatchSize = LUCENE_QUERY_BATCH_SIZE;

        private boolean noDocs = false;

        private long lastSearchIndexerVersion;

        private int reloadCount;

        @Override
        protected LuceneResultRow computeNext() {
            while (!queue.isEmpty() || loadDocs()) {
                return queue.remove();
            }
            return endOfData();
        }

        private LuceneResultRow convertToRow(ScoreDoc doc, IndexSearcher searcher, String excerpt) throws IOException {
            IndexReader reader = searcher.getIndexReader();
            PathStoredFieldVisitor visitor = new PathStoredFieldVisitor();
            reader.document(doc.doc, visitor);
            String path = visitor.getPath();
            if (path != null) {
                if ("".equals(path)) {
                    path = "/";
                }
                if (!parent.isEmpty()) {
                    // TODO OAK-828 this breaks node aggregation
                    // get the base path
                    // ensure the path ends with the given
                    // relative path
                    // if (!path.endsWith("/" + parent)) {
                    // continue;
                    // }
                    path = getAncestorPath(path, parentDepth);
                    // avoid duplicate entries
                    if (seenPaths.contains(path)) {
                        return null;
                    }
                    seenPaths.add(path);
                }
                return new LuceneResultRow(path, doc.score, excerpt);
            }
            return null;
        }

        /**
         * Loads the lucene documents in batches
         * @return true if any document is loaded
         */
        private boolean loadDocs() {
            if (noDocs) {
                return false;
            }
            ScoreDoc lastDocToRecord = null;
            IndexNode indexNode = tracker.acquireIndexNode((String) plan.getAttribute(ATTR_INDEX_PATH));
            checkState(indexNode != null);
            try {
                IndexSearcher searcher = indexNode.getSearcher();
                LuceneRequestFacade luceneRequestFacade = getLuceneRequest(filter, searcher.getIndexReader(), nonFullTextConstraints, indexNode.getDefinition());
                if (luceneRequestFacade.getLuceneRequest() instanceof Query) {
                    Query query = (Query) luceneRequestFacade.getLuceneRequest();
                    TopDocs docs;
                    long time = System.currentTimeMillis();
                    checkForIndexVersionChange(searcher);
                    while (true) {
                        if (lastDoc != null) {
                            LOG.debug("loading the next {} entries for query {}", nextBatchSize, query);
                            docs = searcher.searchAfter(lastDoc, query, nextBatchSize);
                        } else {
                            LOG.debug("loading the first {} entries for query {}", nextBatchSize, query);
                            docs = searcher.search(query, nextBatchSize);
                        }
                        time = System.currentTimeMillis() - time;
                        LOG.debug("... took {} ms", time);
                        nextBatchSize = (int) Math.min(nextBatchSize * 2L, 100000);
                        PropertyRestriction restriction = filter.getPropertyRestriction(QueryConstants.REP_EXCERPT);
                        boolean addExcerpt = restriction != null && restriction.isNotNullRestriction();
                        Analyzer analyzer = indexNode.getDefinition().getAnalyzer();
                        if (addExcerpt) {
                            // setup highlighter
                            QueryScorer scorer = new QueryScorer(query);
                            scorer.setExpandMultiTermQuery(true);
                            highlighter.setFragmentScorer(scorer);
                        }
                        for (ScoreDoc doc : docs.scoreDocs) {
                            String excerpt = null;
                            if (addExcerpt) {
                                excerpt = getExcerpt(analyzer, searcher, doc);
                            }
                            LuceneResultRow row = convertToRow(doc, searcher, excerpt);
                            if (row != null) {
                                queue.add(row);
                            }
                            lastDocToRecord = doc;
                        }
                        if (queue.isEmpty() && docs.scoreDocs.length > 0) {
                            lastDoc = lastDocToRecord;
                        } else {
                            break;
                        }
                    }
                } else if (luceneRequestFacade.getLuceneRequest() instanceof SpellcheckHelper.SpellcheckQuery) {
                    SpellcheckHelper.SpellcheckQuery spellcheckQuery = (SpellcheckHelper.SpellcheckQuery) luceneRequestFacade.getLuceneRequest();
                    noDocs = true;
                    SuggestWord[] suggestWords = SpellcheckHelper.getSpellcheck(spellcheckQuery);
                    // ACL filter spellchecks
                    Collection<String> suggestedWords = new ArrayList<String>(suggestWords.length);
                    QueryParser qp = new QueryParser(Version.LUCENE_47, FieldNames.SUGGEST, indexNode.getDefinition().getAnalyzer());
                    for (SuggestWord suggestion : suggestWords) {
                        Query query = qp.createPhraseQuery(FieldNames.SUGGEST, suggestion.string);
                        TopDocs topDocs = searcher.search(query, 100);
                        if (topDocs.totalHits > 0) {
                            for (ScoreDoc doc : topDocs.scoreDocs) {
                                Document retrievedDoc = searcher.doc(doc.doc);
                                if (filter.isAccessible(retrievedDoc.get(FieldNames.PATH))) {
                                    suggestedWords.add(suggestion.string);
                                    break;
                                }
                            }
                        }
                    }
                    queue.add(new LuceneResultRow(suggestedWords));
                } else if (luceneRequestFacade.getLuceneRequest() instanceof SuggestHelper.SuggestQuery) {
                    SuggestHelper.SuggestQuery suggestQuery = (SuggestHelper.SuggestQuery) luceneRequestFacade.getLuceneRequest();
                    noDocs = true;
                    List<Lookup.LookupResult> lookupResults = SuggestHelper.getSuggestions(indexNode.getLookup(), suggestQuery);
                    // ACL filter suggestions
                    Collection<String> suggestedWords = new ArrayList<String>(lookupResults.size());
                    QueryParser qp = new QueryParser(Version.LUCENE_47, FieldNames.FULLTEXT, indexNode.getDefinition().getAnalyzer());
                    for (Lookup.LookupResult suggestion : lookupResults) {
                        Query query = qp.createPhraseQuery(FieldNames.FULLTEXT, suggestion.key.toString());
                        TopDocs topDocs = searcher.search(query, 100);
                        if (topDocs.totalHits > 0) {
                            for (ScoreDoc doc : topDocs.scoreDocs) {
                                Document retrievedDoc = searcher.doc(doc.doc);
                                if (filter.isAccessible(retrievedDoc.get(FieldNames.PATH))) {
                                    suggestedWords.add("{term=" + suggestion.key + ",weight=" + suggestion.value + "}");
                                    break;
                                }
                            }
                        }
                    }
                    queue.add(new LuceneResultRow(suggestedWords));
                }
            } catch (IOException e) {
                LOG.warn("query via {} failed.", LuceneIndex.this, e);
            } finally {
                indexNode.release();
            }
            if (lastDocToRecord != null) {
                this.lastDoc = lastDocToRecord;
            }
            return !queue.isEmpty();
        }

        private void checkForIndexVersionChange(IndexSearcher searcher) {
            long currentVersion = LucenePropertyIndex.getVersion(searcher);
            if (currentVersion != lastSearchIndexerVersion && lastDoc != null) {
                reloadCount++;
                if (reloadCount > MAX_RELOAD_COUNT) {
                    LOG.error("More than {} index version changes detected for query {}", MAX_RELOAD_COUNT, plan);
                    throw new IllegalStateException("Too many version changes");
                }
                lastDoc = null;
                LOG.debug("Change in index version detected {} => {}. Query would be performed without " + "offset; reload {}", currentVersion, lastSearchIndexerVersion, reloadCount);
            }
            this.lastSearchIndexerVersion = currentVersion;
        }
    };
    SizeEstimator sizeEstimator = new SizeEstimator() {

        @Override
        public long getSize() {
            IndexNode indexNode = tracker.acquireIndexNode((String) plan.getAttribute(ATTR_INDEX_PATH));
            checkState(indexNode != null);
            try {
                IndexSearcher searcher = indexNode.getSearcher();
                LuceneRequestFacade luceneRequestFacade = getLuceneRequest(filter, searcher.getIndexReader(), nonFullTextConstraints, indexNode.getDefinition());
                if (luceneRequestFacade.getLuceneRequest() instanceof Query) {
                    Query query = (Query) luceneRequestFacade.getLuceneRequest();
                    TotalHitCountCollector collector = new TotalHitCountCollector();
                    searcher.search(query, collector);
                    int totalHits = collector.getTotalHits();
                    LOG.debug("Estimated size for query {} is {}", query, totalHits);
                    return totalHits;
                }
                LOG.debug("Estimated size: not a Query: {}", luceneRequestFacade.getLuceneRequest());
            } catch (IOException e) {
                LOG.warn("query via {} failed.", LuceneIndex.this, e);
            } finally {
                indexNode.release();
            }
            return -1;
        }
    };
    return new LucenePathCursor(itr, settings, sizeEstimator, filter);
}

Example 45 with AbstractIterator

use of com.google.common.collect.AbstractIterator in project jackrabbit-oak by apache.

the class LucenePropertyIndex method query.

@Override
public Cursor query(final IndexPlan plan, NodeState rootState) {
    final Filter filter = plan.getFilter();
    final Sort sort = getSort(plan);
    final PlanResult pr = getPlanResult(plan);
    QueryLimits settings = filter.getQueryLimits();
    Iterator<LuceneResultRow> itr = new AbstractIterator<LuceneResultRow>() {

        private final Deque<LuceneResultRow> queue = Queues.newArrayDeque();

        private final Set<String> seenPaths = Sets.newHashSet();

        private ScoreDoc lastDoc;

        private int nextBatchSize = LUCENE_QUERY_BATCH_SIZE;

        private boolean noDocs = false;

        private IndexSearcher indexSearcher;

        private int indexNodeId = -1;

        @Override
        protected LuceneResultRow computeNext() {
            while (!queue.isEmpty() || loadDocs()) {
                return queue.remove();
            }
            releaseSearcher();
            return endOfData();
        }

        private LuceneResultRow convertToRow(ScoreDoc doc, IndexSearcher searcher, Map<String, String> excerpts, Facets facets, String explanation) throws IOException {
            IndexReader reader = searcher.getIndexReader();
            // TODO Look into usage of field cache for retrieving the path
            // instead of reading via reader if no of docs in index are limited
            PathStoredFieldVisitor visitor = new PathStoredFieldVisitor();
            reader.document(doc.doc, visitor);
            String path = visitor.getPath();
            if (path != null) {
                if ("".equals(path)) {
                    path = "/";
                }
                if (pr.isPathTransformed()) {
                    String originalPath = path;
                    path = pr.transformPath(path);
                    if (path == null) {
                        LOG.trace("Ignoring path {} : Transformation returned null", originalPath);
                        return null;
                    }
                    // avoid duplicate entries
                    if (seenPaths.contains(path)) {
                        LOG.trace("Ignoring path {} : Duplicate post transformation", originalPath);
                        return null;
                    }
                    seenPaths.add(path);
                }
                boolean shouldIncludeForHierarchy = shouldInclude(path, plan);
                LOG.trace("Matched path {}; shouldIncludeForHierarchy: {}", path, shouldIncludeForHierarchy);
                return shouldIncludeForHierarchy ? new LuceneResultRow(path, doc.score, excerpts, facets, explanation) : null;
            }
            return null;
        }

        /**
         * Loads the lucene documents in batches
         * @return true if any document is loaded
         */
        private boolean loadDocs() {
            if (noDocs) {
                return false;
            }
            ScoreDoc lastDocToRecord = null;
            final IndexNode indexNode = acquireIndexNode(plan);
            checkState(indexNode != null);
            try {
                IndexSearcher searcher = getCurrentSearcher(indexNode);
                LuceneRequestFacade luceneRequestFacade = getLuceneRequest(plan, augmentorFactory, searcher.getIndexReader());
                if (luceneRequestFacade.getLuceneRequest() instanceof Query) {
                    Query query = (Query) luceneRequestFacade.getLuceneRequest();
                    CustomScoreQuery customScoreQuery = getCustomScoreQuery(plan, query);
                    if (customScoreQuery != null) {
                        query = customScoreQuery;
                    }
                    TopDocs docs;
                    long start = PERF_LOGGER.start();
                    while (true) {
                        if (lastDoc != null) {
                            LOG.debug("loading the next {} entries for query {}", nextBatchSize, query);
                            if (sort == null) {
                                docs = searcher.searchAfter(lastDoc, query, nextBatchSize);
                            } else {
                                docs = searcher.searchAfter(lastDoc, query, nextBatchSize, sort);
                            }
                        } else {
                            LOG.debug("loading the first {} entries for query {}", nextBatchSize, query);
                            if (sort == null) {
                                docs = searcher.search(query, nextBatchSize);
                            } else {
                                docs = searcher.search(query, nextBatchSize, sort);
                            }
                        }
                        PERF_LOGGER.end(start, -1, "{} ...", docs.scoreDocs.length);
                        nextBatchSize = (int) Math.min(nextBatchSize * 2L, 100000);
                        long f = PERF_LOGGER.start();
                        Facets facets = FacetHelper.getFacets(searcher, query, docs, plan, indexNode.getDefinition().isSecureFacets());
                        PERF_LOGGER.end(f, -1, "facets retrieved");
                        Set<String> excerptFields = Sets.newHashSet();
                        for (PropertyRestriction pr : filter.getPropertyRestrictions()) {
                            if (QueryConstants.REP_EXCERPT.equals(pr.propertyName)) {
                                String value = pr.first.getValue(Type.STRING);
                                excerptFields.add(value);
                            }
                        }
                        boolean addExcerpt = excerptFields.size() > 0;
                        PropertyRestriction restriction = filter.getPropertyRestriction(QueryConstants.OAK_SCORE_EXPLANATION);
                        boolean addExplain = restriction != null && restriction.isNotNullRestriction();
                        Analyzer analyzer = indexNode.getDefinition().getAnalyzer();
                        FieldInfos mergedFieldInfos = null;
                        if (addExcerpt) {
                            // setup highlighter
                            QueryScorer scorer = new QueryScorer(query);
                            scorer.setExpandMultiTermQuery(true);
                            highlighter.setFragmentScorer(scorer);
                            mergedFieldInfos = MultiFields.getMergedFieldInfos(searcher.getIndexReader());
                        }
                        for (ScoreDoc doc : docs.scoreDocs) {
                            Map<String, String> excerpts = null;
                            if (addExcerpt) {
                                excerpts = getExcerpt(query, excerptFields, analyzer, searcher, doc, mergedFieldInfos);
                            }
                            String explanation = null;
                            if (addExplain) {
                                explanation = searcher.explain(query, doc.doc).toString();
                            }
                            LuceneResultRow row = convertToRow(doc, searcher, excerpts, facets, explanation);
                            if (row != null) {
                                queue.add(row);
                            }
                            lastDocToRecord = doc;
                        }
                        if (queue.isEmpty() && docs.scoreDocs.length > 0) {
                            // queue is still empty but more results can be fetched
                            // from Lucene so still continue
                            lastDoc = lastDocToRecord;
                        } else {
                            break;
                        }
                    }
                } else if (luceneRequestFacade.getLuceneRequest() instanceof SpellcheckHelper.SpellcheckQuery) {
                    String aclCheckField = indexNode.getDefinition().isFullTextEnabled() ? FieldNames.FULLTEXT : FieldNames.SPELLCHECK;
                    noDocs = true;
                    SpellcheckHelper.SpellcheckQuery spellcheckQuery = (SpellcheckHelper.SpellcheckQuery) luceneRequestFacade.getLuceneRequest();
                    SuggestWord[] suggestWords = SpellcheckHelper.getSpellcheck(spellcheckQuery);
                    // ACL filter spellchecks
                    QueryParser qp = new QueryParser(Version.LUCENE_47, aclCheckField, indexNode.getDefinition().getAnalyzer());
                    for (SuggestWord suggestion : suggestWords) {
                        Query query = qp.createPhraseQuery(aclCheckField, QueryParserBase.escape(suggestion.string));
                        query = addDescendantClauseIfRequired(query, plan);
                        TopDocs topDocs = searcher.search(query, 100);
                        if (topDocs.totalHits > 0) {
                            for (ScoreDoc doc : topDocs.scoreDocs) {
                                Document retrievedDoc = searcher.doc(doc.doc);
                                String prefix = filter.getPath();
                                if (prefix.length() == 1) {
                                    prefix = "";
                                }
                                if (filter.isAccessible(prefix + retrievedDoc.get(FieldNames.PATH))) {
                                    queue.add(new LuceneResultRow(suggestion.string));
                                    break;
                                }
                            }
                        }
                    }
                } else if (luceneRequestFacade.getLuceneRequest() instanceof SuggestHelper.SuggestQuery) {
                    SuggestHelper.SuggestQuery suggestQuery = (SuggestHelper.SuggestQuery) luceneRequestFacade.getLuceneRequest();
                    noDocs = true;
                    List<Lookup.LookupResult> lookupResults = SuggestHelper.getSuggestions(indexNode.getLookup(), suggestQuery);
                    QueryParser qp = new QueryParser(Version.LUCENE_47, FieldNames.SUGGEST, indexNode.getDefinition().isSuggestAnalyzed() ? indexNode.getDefinition().getAnalyzer() : SuggestHelper.getAnalyzer());
                    // ACL filter suggestions
                    for (Lookup.LookupResult suggestion : lookupResults) {
                        Query query = qp.parse("\"" + QueryParserBase.escape(suggestion.key.toString()) + "\"");
                        query = addDescendantClauseIfRequired(query, plan);
                        TopDocs topDocs = searcher.search(query, 100);
                        if (topDocs.totalHits > 0) {
                            for (ScoreDoc doc : topDocs.scoreDocs) {
                                Document retrievedDoc = searcher.doc(doc.doc);
                                String prefix = filter.getPath();
                                if (prefix.length() == 1) {
                                    prefix = "";
                                }
                                if (filter.isAccessible(prefix + retrievedDoc.get(FieldNames.PATH))) {
                                    queue.add(new LuceneResultRow(suggestion.key.toString(), suggestion.value));
                                    break;
                                }
                            }
                        }
                    }
                }
            } catch (Exception e) {
                LOG.warn("query via {} failed.", LucenePropertyIndex.this, e);
            } finally {
                indexNode.release();
            }
            if (lastDocToRecord != null) {
                this.lastDoc = lastDocToRecord;
            }
            return !queue.isEmpty();
        }

        private IndexSearcher getCurrentSearcher(IndexNode indexNode) {
            // the searcher would be refreshed as done earlier
            if (indexNodeId != indexNode.getIndexNodeId()) {
                // if already initialized then log about change
                if (indexNodeId > 0) {
                    LOG.debug("Change in index version detected. Query would be performed without offset");
                }
                indexSearcher = indexNode.getSearcher();
                indexNodeId = indexNode.getIndexNodeId();
                lastDoc = null;
            }
            return indexSearcher;
        }

        private void releaseSearcher() {
            // For now nullifying it.
            indexSearcher = null;
        }
    };
    SizeEstimator sizeEstimator = new SizeEstimator() {

        @Override
        public long getSize() {
            IndexNode indexNode = acquireIndexNode(plan);
            checkState(indexNode != null);
            try {
                IndexSearcher searcher = indexNode.getSearcher();
                LuceneRequestFacade luceneRequestFacade = getLuceneRequest(plan, augmentorFactory, searcher.getIndexReader());
                if (luceneRequestFacade.getLuceneRequest() instanceof Query) {
                    Query query = (Query) luceneRequestFacade.getLuceneRequest();
                    TotalHitCountCollector collector = new TotalHitCountCollector();
                    searcher.search(query, collector);
                    int totalHits = collector.getTotalHits();
                    LOG.debug("Estimated size for query {} is {}", query, totalHits);
                    return totalHits;
                }
                LOG.debug("estimate size: not a Query: {}", luceneRequestFacade.getLuceneRequest());
            } catch (IOException e) {
                LOG.warn("query via {} failed.", LucenePropertyIndex.this, e);
            } finally {
                indexNode.release();
            }
            return -1;
        }
    };
    if (pr.hasPropertyIndexResult() || pr.evaluateSyncNodeTypeRestriction()) {
        itr = mergePropertyIndexResult(plan, rootState, itr);
    }
    return new LucenePathCursor(itr, plan, settings, sizeEstimator);
}