package org.apache.lucene.index;
/*
* 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.HashMap;
import java.util.Map;
import org.apache.lucene.util.Bits;
import org.apache.lucene.index.DirectoryReader; // javadoc
import org.apache.lucene.index.FieldInfo.DocValuesType;
import org.apache.lucene.index.MultiDocValues.MultiSortedDocValues;
import org.apache.lucene.index.MultiDocValues.MultiSortedSetDocValues;
import org.apache.lucene.index.MultiDocValues.OrdinalMap;
import org.apache.lucene.index.MultiReader; // javadoc
/**
* This class forces a composite reader (eg a {@link
* MultiReader} or {@link DirectoryReader}) to emulate an
* atomic reader. This requires implementing the postings
* APIs on-the-fly, using the static methods in {@link
* MultiFields}, {@link MultiDocValues}, by stepping through
* the sub-readers to merge fields/terms, appending docs, etc.
*
* <p><b>NOTE</b>: this class almost always results in a
* performance hit. If this is important to your use case,
* you'll get better performance by gathering the sub readers using
* {@link IndexReader#getContext()} to get the
* atomic leaves and then operate per-AtomicReader,
* instead of using this class.
*/
public final class SlowCompositeReaderWrapper extends AtomicReader {
private final CompositeReader in;
private final Fields fields;
private final Bits liveDocs;
/** This method is sugar for getting an {@link AtomicReader} from
* an {@link IndexReader} of any kind. If the reader is already atomic,
* it is returned unchanged, otherwise wrapped by this class.
*/
public static AtomicReader wrap(IndexReader reader) throws IOException {
if (reader instanceof CompositeReader) {
return new SlowCompositeReaderWrapper((CompositeReader) reader);
} else {
assert reader instanceof AtomicReader;
return (AtomicReader) reader;
}
}
private SlowCompositeReaderWrapper(CompositeReader reader) throws IOException {
super();
in = reader;
fields = MultiFields.getFields(in);
liveDocs = MultiFields.getLiveDocs(in);
in.registerParentReader(this);
}
@Override
public String toString() {
return "SlowCompositeReaderWrapper(" + in + ")";
}
@Override
public Fields fields() {
ensureOpen();
return fields;
}
@Override
public NumericDocValues getNumericDocValues(String field) throws IOException {
ensureOpen();
return MultiDocValues.getNumericValues(in, field);
}
@Override
public Bits getDocsWithField(String field) throws IOException {
ensureOpen();
return MultiDocValues.getDocsWithField(in, field);
}
@Override
public BinaryDocValues getBinaryDocValues(String field) throws IOException {
ensureOpen();
return MultiDocValues.getBinaryValues(in, field);
}
@Override
public SortedDocValues getSortedDocValues(String field) throws IOException {
ensureOpen();
OrdinalMap map = null;
synchronized (cachedOrdMaps) {
map = cachedOrdMaps.get(field);
if (map == null) {
// uncached, or not a multi dv
SortedDocValues dv = MultiDocValues.getSortedValues(in, field);
if (dv instanceof MultiSortedDocValues) {
map = ((MultiSortedDocValues)dv).mapping;
if (map.owner == getCoreCacheKey()) {
cachedOrdMaps.put(field, map);
}
}
return dv;
}
}
// cached ordinal map
if (getFieldInfos().fieldInfo(field).getDocValuesType() != DocValuesType.SORTED) {
return null;
}
int size = in.leaves().size();
final SortedDocValues[] values = new SortedDocValues[size];
final int[] starts = new int[size+1];
for (int i = 0; i < size; i++) {
AtomicReaderContext context = in.leaves().get(i);
SortedDocValues v = context.reader().getSortedDocValues(field);
if (v == null) {
v = SortedDocValues.EMPTY;
}
values[i] = v;
starts[i] = context.docBase;
}
starts[size] = maxDoc();
return new MultiSortedDocValues(values, starts, map);
}
@Override
public SortedSetDocValues getSortedSetDocValues(String field) throws IOException {
ensureOpen();
OrdinalMap map = null;
synchronized (cachedOrdMaps) {
map = cachedOrdMaps.get(field);
if (map == null) {
// uncached, or not a multi dv
SortedSetDocValues dv = MultiDocValues.getSortedSetValues(in, field);
if (dv instanceof MultiSortedSetDocValues) {
map = ((MultiSortedSetDocValues)dv).mapping;
if (map.owner == getCoreCacheKey()) {
cachedOrdMaps.put(field, map);
}
}
return dv;
}
}
// cached ordinal map
if (getFieldInfos().fieldInfo(field).getDocValuesType() != DocValuesType.SORTED_SET) {
return null;
}
assert map != null;
int size = in.leaves().size();
final SortedSetDocValues[] values = new SortedSetDocValues[size];
final int[] starts = new int[size+1];
for (int i = 0; i < size; i++) {
AtomicReaderContext context = in.leaves().get(i);
SortedSetDocValues v = context.reader().getSortedSetDocValues(field);
if (v == null) {
v = SortedSetDocValues.EMPTY;
}
values[i] = v;
starts[i] = context.docBase;
}
starts[size] = maxDoc();
return new MultiSortedSetDocValues(values, starts, map);
}
// TODO: this could really be a weak map somewhere else on the coreCacheKey,
// but do we really need to optimize slow-wrapper any more?
private final Map<String,OrdinalMap> cachedOrdMaps = new HashMap<String,OrdinalMap>();
@Override
public NumericDocValues getNormValues(String field) throws IOException {
ensureOpen();
return MultiDocValues.getNormValues(in, field);
}
@Override
public Fields getTermVectors(int docID) throws IOException {
ensureOpen();
return in.getTermVectors(docID);
}
@Override
public int numDocs() {
// Don't call ensureOpen() here (it could affect performance)
return in.numDocs();
}
@Override
public int maxDoc() {
// Don't call ensureOpen() here (it could affect performance)
return in.maxDoc();
}
@Override
public void document(int docID, StoredFieldVisitor visitor) throws IOException {
ensureOpen();
in.document(docID, visitor);
}
@Override
public Bits getLiveDocs() {
ensureOpen();
return liveDocs;
}
@Override
public FieldInfos getFieldInfos() {
ensureOpen();
return MultiFields.getMergedFieldInfos(in);
}
@Override
public Object getCoreCacheKey() {
return in.getCoreCacheKey();
}
@Override
public Object getCombinedCoreAndDeletesKey() {
return in.getCombinedCoreAndDeletesKey();
}
@Override
protected void doClose() throws IOException {
// TODO: as this is a wrapper, should we really close the delegate?
in.close();
}
}