package org.apache.lucene.search;
/**
* 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.io.IOException;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.FieldSelector;
import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexReader.AtomicReaderContext;
import org.apache.lucene.index.IndexReader.ReaderContext;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.Weight.ScorerContext;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.NIOFSDirectory; // javadoc
import org.apache.lucene.util.ReaderUtil;
import org.apache.lucene.util.ThreadInterruptedException;
/** Implements search over a single IndexReader.
*
* <p>Applications usually need only call the inherited
* {@link #search(Query,int)}
* or {@link #search(Query,Filter,int)} methods. For performance reasons it is
* recommended to open only one IndexSearcher and use it for all of your searches.
*
* <a name="thread-safety"></a><p><b>NOTE</b>: <code>{@link
* IndexSearcher}</code> instances are completely
* thread safe, meaning multiple threads can call any of its
* methods, concurrently. If your application requires
* external synchronization, you should <b>not</b>
* synchronize on the <code>IndexSearcher</code> instance;
* use your own (non-Lucene) objects instead.</p>
*/
public class IndexSearcher {
final IndexReader reader; // package private for testing!
private boolean closeReader;
// NOTE: these members might change in incompatible ways
// in the next release
protected final ReaderContext readerContext;
protected final AtomicReaderContext[] leafContexts;
// used with executor - each slice holds a set of leafs executed within one thread
protected final LeafSlice[] leafSlices;
// These are only used for multi-threaded search
private final ExecutorService executor;
// the default SimilarityProvider
private static final SimilarityProvider defaultProvider = new DefaultSimilarityProvider();
/**
* Expert: returns a default SimilarityProvider instance.
* In general, this method is only called to initialize searchers and writers.
* User code and query implementations should respect
* {@link IndexSearcher#getSimilarityProvider()}.
* @lucene.internal
*/
public static SimilarityProvider getDefaultSimilarityProvider() {
return defaultProvider;
}
/** The SimilarityProvider implementation used by this searcher. */
private SimilarityProvider similarityProvider = defaultProvider;
/** Creates a searcher searching the index in the named
* directory, with readOnly=true
* @param path directory where IndexReader will be opened
* @throws CorruptIndexException if the index is corrupt
* @throws IOException if there is a low-level IO error
*/
public IndexSearcher(Directory path) throws CorruptIndexException, IOException {
this(IndexReader.open(path, true), true, null);
}
/** Creates a searcher searching the index in the named
* directory. You should pass readOnly=true, since it
* gives much better concurrent performance, unless you
* intend to do write operations (delete documents or
* change norms) with the underlying IndexReader.
* @param path directory where IndexReader will be opened
* @param readOnly if true, the underlying IndexReader
* will be opened readOnly
* @throws CorruptIndexException if the index is corrupt
* @throws IOException if there is a low-level IO error
*/
public IndexSearcher(Directory path, boolean readOnly) throws CorruptIndexException, IOException {
this(IndexReader.open(path, readOnly), true, null);
}
/** Creates a searcher searching the provided index. */
public IndexSearcher(IndexReader r) {
this(r, false, null);
}
/** Runs searches for each segment separately, using the
* provided ExecutorService. IndexSearcher will not
* shutdown/awaitTermination this ExecutorService on
* close; you must do so, eventually, on your own. NOTE:
* if you are using {@link NIOFSDirectory}, do not use
* the shutdownNow method of ExecutorService as this uses
* Thread.interrupt under-the-hood which can silently
* close file descriptors (see <a
* href="https://issues.apache.org/jira/browse/LUCENE-2239">LUCENE-2239</a>).
*
* @lucene.experimental */
public IndexSearcher(IndexReader r, ExecutorService executor) {
this(r, false, executor);
}
/**
* Creates a searcher searching the provided top-level {@link ReaderContext}.
* <p>
* Given a non-<code>null</code> {@link ExecutorService} this method runs
* searches for each segment separately, using the provided ExecutorService.
* IndexSearcher will not shutdown/awaitTermination this ExecutorService on
* close; you must do so, eventually, on your own. NOTE: if you are using
* {@link NIOFSDirectory}, do not use the shutdownNow method of
* ExecutorService as this uses Thread.interrupt under-the-hood which can
* silently close file descriptors (see <a
* href="https://issues.apache.org/jira/browse/LUCENE-2239">LUCENE-2239</a>).
*
* @see ReaderContext
* @see IndexReader#getTopReaderContext()
* @lucene.experimental
*/
public IndexSearcher(ReaderContext context, ExecutorService executor) {
this(context, false, executor);
}
/**
* Creates a searcher searching the provided top-level {@link ReaderContext}.
*
* @see ReaderContext
* @see IndexReader#getTopReaderContext()
* @lucene.experimental
*/
public IndexSearcher(ReaderContext context) {
this(context, (ExecutorService) null);
}
// convenience ctor for other IR based ctors
private IndexSearcher(IndexReader reader, boolean closeReader, ExecutorService executor) {
this(reader.getTopReaderContext(), closeReader, executor);
}
private IndexSearcher(ReaderContext context, boolean closeReader, ExecutorService executor) {
assert context.isTopLevel: "IndexSearcher's ReaderContext must be topLevel for reader" + context.reader;
reader = context.reader;
this.executor = executor;
this.closeReader = closeReader;
this.readerContext = context;
leafContexts = ReaderUtil.leaves(context);
this.leafSlices = executor == null ? null : slices(leafContexts);
}
/**
* Expert: Creates an array of leaf slices each holding a subset of the given leaves.
* Each {@link LeafSlice} is executed in a single thread. By default there
* will be one {@link LeafSlice} per leaf ({@link AtomicReaderContext}).
*/
protected LeafSlice[] slices(AtomicReaderContext...leaves) {
LeafSlice[] slices = new LeafSlice[leaves.length];
for (int i = 0; i < slices.length; i++) {
slices[i] = new LeafSlice(leaves[i]);
}
return slices;
}
/** Return the {@link IndexReader} this searches. */
public IndexReader getIndexReader() {
return reader;
}
/** Expert: Returns one greater than the largest possible document number.
*
* @see org.apache.lucene.index.IndexReader#maxDoc()
*/
public int maxDoc() {
return reader.maxDoc();
}
/** Returns total docFreq for this term. */
public int docFreq(final Term term) throws IOException {
if (executor == null) {
return reader.docFreq(term);
} else {
final ExecutionHelper<Integer> runner = new ExecutionHelper<Integer>(executor);
for(int i = 0; i < leafContexts.length; i++) {
final IndexReader leaf = leafContexts[i].reader;
runner.submit(new Callable<Integer>() {
public Integer call() throws IOException {
return Integer.valueOf(leaf.docFreq(term));
}
});
}
int docFreq = 0;
for (Integer num : runner) {
docFreq += num.intValue();
}
return docFreq;
}
}
/* Sugar for .getIndexReader().document(docID) */
public Document doc(int docID) throws CorruptIndexException, IOException {
return reader.document(docID);
}
/* Sugar for .getIndexReader().document(docID, fieldSelector) */
public Document doc(int docID, FieldSelector fieldSelector) throws CorruptIndexException, IOException {
return reader.document(docID, fieldSelector);
}
/** Expert: Set the SimilarityProvider implementation used by this Searcher.
*
*/
public void setSimilarityProvider(SimilarityProvider similarityProvider) {
this.similarityProvider = similarityProvider;
}
public SimilarityProvider getSimilarityProvider() {
return similarityProvider;
}
/**
* Note that the underlying IndexReader is not closed, if
* IndexSearcher was constructed with IndexSearcher(IndexReader r).
* If the IndexReader was supplied implicitly by specifying a directory, then
* the IndexReader is closed.
*/
public void close() throws IOException {
if (closeReader) {
reader.close();
}
}
/** Finds the top <code>n</code>
* hits for <code>query</code>.
*
* @throws BooleanQuery.TooManyClauses
*/
public TopDocs search(Query query, int n)
throws IOException {
return search(query, null, n);
}
/** Finds the top <code>n</code>
* hits for <code>query</code>, applying <code>filter</code> if non-null.
*
* @throws BooleanQuery.TooManyClauses
*/
public TopDocs search(Query query, Filter filter, int n)
throws IOException {
return search(createWeight(query), filter, n);
}
/** Lower-level search API.
*
* <p>{@link Collector#collect(int)} is called for every matching
* document.
* <br>Collector-based access to remote indexes is discouraged.
*
* <p>Applications should only use this if they need <i>all</i> of the
* matching documents. The high-level search API ({@link
* IndexSearcher#search(Query, Filter, int)}) is usually more efficient, as it skips
* non-high-scoring hits.
*
* @param query to match documents
* @param filter if non-null, used to permit documents to be collected.
* @param results to receive hits
* @throws BooleanQuery.TooManyClauses
*/
public void search(Query query, Filter filter, Collector results)
throws IOException {
search(leafContexts, createWeight(query), filter, results);
}
/** Lower-level search API.
*
* <p>{@link Collector#collect(int)} is called for every matching document.
*
* <p>Applications should only use this if they need <i>all</i> of the
* matching documents. The high-level search API ({@link
* IndexSearcher#search(Query, int)}) is usually more efficient, as it skips
* non-high-scoring hits.
* <p>Note: The <code>score</code> passed to this method is a raw score.
* In other words, the score will not necessarily be a float whose value is
* between 0 and 1.
* @throws BooleanQuery.TooManyClauses
*/
public void search(Query query, Collector results)
throws IOException {
search(leafContexts, createWeight(query), null, results);
}
/** Search implementation with arbitrary sorting. Finds
* the top <code>n</code> hits for <code>query</code>, applying
* <code>filter</code> if non-null, and sorting the hits by the criteria in
* <code>sort</code>.
*
* <p>NOTE: this does not compute scores by default; use
* {@link IndexSearcher#setDefaultFieldSortScoring} to
* enable scoring.
*
* @throws BooleanQuery.TooManyClauses
*/
public TopFieldDocs search(Query query, Filter filter, int n,
Sort sort) throws IOException {
return search(createWeight(query), filter, n, sort);
}
/**
* Search implementation with arbitrary sorting and no filter.
* @param query The query to search for
* @param n Return only the top n results
* @param sort The {@link org.apache.lucene.search.Sort} object
* @return The top docs, sorted according to the supplied {@link org.apache.lucene.search.Sort} instance
* @throws IOException
*/
public TopFieldDocs search(Query query, int n,
Sort sort) throws IOException {
return search(createWeight(query), null, n, sort);
}
/** Expert: Low-level search implementation. Finds the top <code>n</code>
* hits for <code>query</code>, applying <code>filter</code> if non-null.
*
* <p>Applications should usually call {@link IndexSearcher#search(Query,int)} or
* {@link IndexSearcher#search(Query,Filter,int)} instead.
* @throws BooleanQuery.TooManyClauses
*/
protected TopDocs search(Weight weight, Filter filter, int nDocs) throws IOException {
if (executor == null) {
return search(leafContexts, weight, filter, nDocs);
} else {
final HitQueue hq = new HitQueue(nDocs, false);
final Lock lock = new ReentrantLock();
final ExecutionHelper<TopDocs> runner = new ExecutionHelper<TopDocs>(executor);
for (int i = 0; i < leafSlices.length; i++) { // search each sub
runner.submit(
new SearcherCallableNoSort(lock, this, leafSlices[i], weight, filter, nDocs, hq));
}
int totalHits = 0;
float maxScore = Float.NEGATIVE_INFINITY;
for (final TopDocs topDocs : runner) {
if(topDocs.totalHits != 0) {
totalHits += topDocs.totalHits;
maxScore = Math.max(maxScore, topDocs.getMaxScore());
}
}
final ScoreDoc[] scoreDocs = new ScoreDoc[hq.size()];
for (int i = hq.size() - 1; i >= 0; i--) // put docs in array
scoreDocs[i] = hq.pop();
return new TopDocs(totalHits, scoreDocs, maxScore);
}
}
/** Expert: Low-level search implementation. Finds the top <code>n</code>
* hits for <code>query</code>, using the given leaf readers applying <code>filter</code> if non-null.
*
* <p>Applications should usually call {@link IndexSearcher#search(Query,int)} or
* {@link IndexSearcher#search(Query,Filter,int)} instead.
* @throws BooleanQuery.TooManyClauses
*/
protected TopDocs search(AtomicReaderContext[] leaves, Weight weight, Filter filter, int nDocs) throws IOException {
// single thread
int limit = reader.maxDoc();
if (limit == 0) {
limit = 1;
}
nDocs = Math.min(nDocs, limit);
TopScoreDocCollector collector = TopScoreDocCollector.create(nDocs, !weight.scoresDocsOutOfOrder());
search(leaves, weight, filter, collector);
return collector.topDocs();
}
/** Expert: Low-level search implementation with arbitrary sorting. Finds
* the top <code>n</code> hits for <code>query</code>, applying
* <code>filter</code> if non-null, and sorting the hits by the criteria in
* <code>sort</code>.
*
* <p>Applications should usually call {@link
* IndexSearcher#search(Query,Filter,int,Sort)} instead.
*
* @throws BooleanQuery.TooManyClauses
*/
protected TopFieldDocs search(Weight weight, Filter filter,
final int nDocs, Sort sort) throws IOException {
return search(weight, filter, nDocs, sort, true);
}
/**
* Just like {@link #search(Weight, Filter, int, Sort)}, but you choose
* whether or not the fields in the returned {@link FieldDoc} instances should
* be set by specifying fillFields.
*
* <p>NOTE: this does not compute scores by default. If you
* need scores, create a {@link TopFieldCollector}
* instance by calling {@link TopFieldCollector#create} and
* then pass that to {@link #search(IndexReader.AtomicReaderContext[], Weight, Filter,
* Collector)}.</p>
*/
protected TopFieldDocs search(Weight weight, Filter filter, int nDocs,
Sort sort, boolean fillFields)
throws IOException {
if (sort == null) throw new NullPointerException();
if (executor == null) {
// use all leaves here!
return search (leafContexts, weight, filter, nDocs, sort, fillFields);
} else {
final TopFieldCollector topCollector = TopFieldCollector.create(sort, nDocs,
fillFields,
fieldSortDoTrackScores,
fieldSortDoMaxScore,
false);
final Lock lock = new ReentrantLock();
final ExecutionHelper<TopFieldDocs> runner = new ExecutionHelper<TopFieldDocs>(executor);
for (int i = 0; i < leafSlices.length; i++) { // search each leaf slice
runner.submit(
new SearcherCallableWithSort(lock, this, leafSlices[i], weight, filter, nDocs, topCollector, sort));
}
int totalHits = 0;
float maxScore = Float.NEGATIVE_INFINITY;
for (final TopFieldDocs topFieldDocs : runner) {
if (topFieldDocs.totalHits != 0) {
totalHits += topFieldDocs.totalHits;
maxScore = Math.max(maxScore, topFieldDocs.getMaxScore());
}
}
final TopFieldDocs topDocs = (TopFieldDocs) topCollector.topDocs();
return new TopFieldDocs(totalHits, topDocs.scoreDocs, topDocs.fields, topDocs.getMaxScore());
}
}
/**
* Just like {@link #search(Weight, Filter, int, Sort)}, but you choose
* whether or not the fields in the returned {@link FieldDoc} instances should
* be set by specifying fillFields.
*
* <p>NOTE: this does not compute scores by default. If you
* need scores, create a {@link TopFieldCollector}
* instance by calling {@link TopFieldCollector#create} and
* then pass that to {@link #search(IndexReader.AtomicReaderContext[], Weight, Filter,
* Collector)}.</p>
*/
protected TopFieldDocs search(AtomicReaderContext[] leaves, Weight weight, Filter filter, int nDocs,
Sort sort, boolean fillFields) throws IOException {
// single thread
int limit = reader.maxDoc();
if (limit == 0) {
limit = 1;
}
nDocs = Math.min(nDocs, limit);
TopFieldCollector collector = TopFieldCollector.create(sort, nDocs,
fillFields, fieldSortDoTrackScores, fieldSortDoMaxScore, !weight.scoresDocsOutOfOrder());
search(leaves, weight, filter, collector);
return (TopFieldDocs) collector.topDocs();
}
/**
* Lower-level search API.
*
* <p>
* {@link Collector#collect(int)} is called for every document. <br>
* Collector-based access to remote indexes is discouraged.
*
* <p>
* Applications should only use this if they need <i>all</i> of the matching
* documents. The high-level search API ({@link IndexSearcher#search(Query,int)}) is
* usually more efficient, as it skips non-high-scoring hits.
*
* <p>
* NOTE: this method executes the searches on all given leaves exclusively.
* To search across all the searchers leaves use {@link #leafContexts}.
*
* @param leaves
* the searchers leaves to execute the searches on
* @param weight
* to match documents
* @param filter
* if non-null, used to permit documents to be collected.
* @param collector
* to receive hits
* @throws BooleanQuery.TooManyClauses
*/
protected void search(AtomicReaderContext[] leaves, Weight weight, Filter filter, Collector collector)
throws IOException {
// TODO: should we make this
// threaded...? the Collector could be sync'd?
ScorerContext scorerContext = ScorerContext.def().scoreDocsInOrder(true).topScorer(true);
// always use single thread:
if (filter == null) {
for (int i = 0; i < leaves.length; i++) { // search each subreader
collector.setNextReader(leaves[i]);
scorerContext = scorerContext.scoreDocsInOrder(!collector.acceptsDocsOutOfOrder());
Scorer scorer = weight.scorer(leaves[i], scorerContext);
if (scorer != null) {
scorer.score(collector);
}
}
} else {
for (int i = 0; i < leaves.length; i++) { // search each subreader
collector.setNextReader(leaves[i]);
searchWithFilter(leaves[i], weight, filter, collector);
}
}
}
private void searchWithFilter(AtomicReaderContext context, Weight weight,
final Filter filter, final Collector collector) throws IOException {
assert filter != null;
Scorer scorer = weight.scorer(context, ScorerContext.def());
if (scorer == null) {
return;
}
int docID = scorer.docID();
assert docID == -1 || docID == DocIdSetIterator.NO_MORE_DOCS;
// CHECKME: use ConjunctionScorer here?
DocIdSet filterDocIdSet = filter.getDocIdSet(context);
if (filterDocIdSet == null) {
// this means the filter does not accept any documents.
return;
}
DocIdSetIterator filterIter = filterDocIdSet.iterator();
if (filterIter == null) {
// this means the filter does not accept any documents.
return;
}
int filterDoc = filterIter.nextDoc();
int scorerDoc = scorer.advance(filterDoc);
collector.setScorer(scorer);
while (true) {
if (scorerDoc == filterDoc) {
// Check if scorer has exhausted, only before collecting.
if (scorerDoc == DocIdSetIterator.NO_MORE_DOCS) {
break;
}
collector.collect(scorerDoc);
filterDoc = filterIter.nextDoc();
scorerDoc = scorer.advance(filterDoc);
} else if (scorerDoc > filterDoc) {
filterDoc = filterIter.advance(scorerDoc);
} else {
scorerDoc = scorer.advance(filterDoc);
}
}
}
/** Expert: called to re-write queries into primitive queries.
* @throws BooleanQuery.TooManyClauses
*/
public Query rewrite(Query original) throws IOException {
Query query = original;
for (Query rewrittenQuery = query.rewrite(reader); rewrittenQuery != query;
rewrittenQuery = query.rewrite(reader)) {
query = rewrittenQuery;
}
return query;
}
/** Returns an Explanation that describes how <code>doc</code> scored against
* <code>query</code>.
*
* <p>This is intended to be used in developing Similarity implementations,
* and, for good performance, should not be displayed with every hit.
* Computing an explanation is as expensive as executing the query over the
* entire index.
*/
public Explanation explain(Query query, int doc) throws IOException {
return explain(createWeight(query), doc);
}
/** Expert: low-level implementation method
* Returns an Explanation that describes how <code>doc</code> scored against
* <code>weight</code>.
*
* <p>This is intended to be used in developing Similarity implementations,
* and, for good performance, should not be displayed with every hit.
* Computing an explanation is as expensive as executing the query over the
* entire index.
* <p>Applications should call {@link IndexSearcher#explain(Query, int)}.
* @throws BooleanQuery.TooManyClauses
*/
protected Explanation explain(Weight weight, int doc) throws IOException {
int n = ReaderUtil.subIndex(doc, leafContexts);
int deBasedDoc = doc - leafContexts[n].docBase;
return weight.explain(leafContexts[n], deBasedDoc);
}
private boolean fieldSortDoTrackScores;
private boolean fieldSortDoMaxScore;
/** By default, no scores are computed when sorting by
* field (using {@link #search(Query,Filter,int,Sort)}).
* You can change that, per IndexSearcher instance, by
* calling this method. Note that this will incur a CPU
* cost.
*
* @param doTrackScores If true, then scores are
* returned for every matching document in {@link
* TopFieldDocs}.
*
* @param doMaxScore If true, then the max score for all
* matching docs is computed. */
public void setDefaultFieldSortScoring(boolean doTrackScores, boolean doMaxScore) {
fieldSortDoTrackScores = doTrackScores;
fieldSortDoMaxScore = doMaxScore;
}
/**
* creates a weight for <code>query</code>
* @return new weight
*/
protected Weight createWeight(Query query) throws IOException {
return query.weight(this);
}
/**
* Returns this searchers the top-level {@link ReaderContext}.
* @see IndexReader#getTopReaderContext()
*/
/* sugar for #getReader().getTopReaderContext() */
public ReaderContext getTopReaderContext() {
return readerContext;
}
/**
* A thread subclass for searching a single searchable
*/
private static final class SearcherCallableNoSort implements Callable<TopDocs> {
private final Lock lock;
private final IndexSearcher searcher;
private final Weight weight;
private final Filter filter;
private final int nDocs;
private final HitQueue hq;
private final LeafSlice slice;
public SearcherCallableNoSort(Lock lock, IndexSearcher searcher, LeafSlice slice, Weight weight,
Filter filter, int nDocs, HitQueue hq) {
this.lock = lock;
this.searcher = searcher;
this.weight = weight;
this.filter = filter;
this.nDocs = nDocs;
this.hq = hq;
this.slice = slice;
}
public TopDocs call() throws IOException {
final TopDocs docs = searcher.search (slice.leaves, weight, filter, nDocs);
final ScoreDoc[] scoreDocs = docs.scoreDocs;
for (int j = 0; j < scoreDocs.length; j++) { // merge scoreDocs into hq
final ScoreDoc scoreDoc = scoreDocs[j];
//it would be so nice if we had a thread-safe insert
lock.lock();
try {
if (scoreDoc == hq.insertWithOverflow(scoreDoc))
break;
} finally {
lock.unlock();
}
}
return docs;
}
}
/**
* A thread subclass for searching a single searchable
*/
private static final class SearcherCallableWithSort implements Callable<TopFieldDocs> {
private final Lock lock;
private final IndexSearcher searcher;
private final Weight weight;
private final Filter filter;
private final int nDocs;
private final TopFieldCollector hq;
private final Sort sort;
private final LeafSlice slice;
public SearcherCallableWithSort(Lock lock, IndexSearcher searcher, LeafSlice slice, Weight weight,
Filter filter, int nDocs, TopFieldCollector hq, Sort sort) {
this.lock = lock;
this.searcher = searcher;
this.weight = weight;
this.filter = filter;
this.nDocs = nDocs;
this.hq = hq;
this.sort = sort;
this.slice = slice;
}
private final class FakeScorer extends Scorer {
float score;
int doc;
public FakeScorer() {
super(null);
}
@Override
public int advance(int target) {
throw new UnsupportedOperationException();
}
@Override
public int docID() {
return doc;
}
@Override
public float freq() {
throw new UnsupportedOperationException();
}
@Override
public int nextDoc() {
throw new UnsupportedOperationException();
}
@Override
public float score() {
return score;
}
}
private final FakeScorer fakeScorer = new FakeScorer();
public TopFieldDocs call() throws IOException {
assert slice.leaves.length == 1;
final TopFieldDocs docs = searcher.search (slice.leaves, weight, filter, nDocs, sort, true);
lock.lock();
try {
final int base = slice.leaves[0].docBase;
hq.setNextReader(slice.leaves[0]);
hq.setScorer(fakeScorer);
for(ScoreDoc scoreDoc : docs.scoreDocs) {
fakeScorer.doc = scoreDoc.doc - base;
fakeScorer.score = scoreDoc.score;
hq.collect(scoreDoc.doc-base);
}
} finally {
lock.unlock();
}
return docs;
}
}
/**
* A helper class that wraps a {@link CompletionService} and provides an
* iterable interface to the completed {@link Callable} instances.
*
* @param <T>
* the type of the {@link Callable} return value
*/
private static final class ExecutionHelper<T> implements Iterator<T>, Iterable<T> {
private final CompletionService<T> service;
private int numTasks;
ExecutionHelper(final Executor executor) {
this.service = new ExecutorCompletionService<T>(executor);
}
public boolean hasNext() {
return numTasks > 0;
}
public void submit(Callable<T> task) {
this.service.submit(task);
++numTasks;
}
public T next() {
if(!this.hasNext())
throw new NoSuchElementException();
try {
return service.take().get();
} catch (InterruptedException e) {
throw new ThreadInterruptedException(e);
} catch (ExecutionException e) {
throw new RuntimeException(e);
} finally {
--numTasks;
}
}
public void remove() {
throw new UnsupportedOperationException();
}
public Iterator<T> iterator() {
// use the shortcut here - this is only used in a private context
return this;
}
}
/**
* A class holding a subset of the {@link IndexSearcher}s leaf contexts to be
* executed within a single thread.
*
* @lucene.experimental
*/
public static class LeafSlice {
final AtomicReaderContext[] leaves;
public LeafSlice(AtomicReaderContext...leaves) {
this.leaves = leaves;
}
}
}