| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.lucene.index; |
| |
| |
| import java.io.IOException; |
| import java.util.Collection; |
| import java.util.Objects; |
| |
| import org.apache.lucene.codecs.DocValuesProducer; |
| import org.apache.lucene.codecs.FieldsProducer; |
| import org.apache.lucene.codecs.NormsProducer; |
| import org.apache.lucene.codecs.PointsReader; |
| import org.apache.lucene.codecs.StoredFieldsReader; |
| import org.apache.lucene.codecs.TermVectorsReader; |
| import org.apache.lucene.util.Accountable; |
| import org.apache.lucene.util.Bits; |
| |
| /** |
| * A <code>FilterCodecReader</code> contains another CodecReader, which it |
| * uses as its basic source of data, possibly transforming the data along the |
| * way or providing additional functionality. |
| * <p><b>NOTE</b>: If this {@link FilterCodecReader} does not change the |
| * content the contained reader, you could consider delegating calls to |
| * {@link #getCoreCacheHelper()} and {@link #getReaderCacheHelper()}. |
| */ |
| public abstract class FilterCodecReader extends CodecReader { |
| |
| /** Get the wrapped instance by <code>reader</code> as long as this reader is |
| * an instance of {@link FilterCodecReader}. */ |
| public static CodecReader unwrap(CodecReader reader) { |
| while (reader instanceof FilterCodecReader) { |
| reader = ((FilterCodecReader) reader).getDelegate(); |
| } |
| return reader; |
| } |
| /** |
| * The underlying CodecReader instance. |
| */ |
| protected final CodecReader in; |
| |
| /** |
| * Creates a new FilterCodecReader. |
| * @param in the underlying CodecReader instance. |
| */ |
| public FilterCodecReader(CodecReader in) { |
| this.in = Objects.requireNonNull(in); |
| } |
| |
| @Override |
| public StoredFieldsReader getFieldsReader() { |
| return in.getFieldsReader(); |
| } |
| |
| @Override |
| public TermVectorsReader getTermVectorsReader() { |
| return in.getTermVectorsReader(); |
| } |
| |
| @Override |
| public NormsProducer getNormsReader() { |
| return in.getNormsReader(); |
| } |
| |
| @Override |
| public DocValuesProducer getDocValuesReader() { |
| return in.getDocValuesReader(); |
| } |
| |
| @Override |
| public FieldsProducer getPostingsReader() { |
| return in.getPostingsReader(); |
| } |
| |
| @Override |
| public Bits getLiveDocs() { |
| return in.getLiveDocs(); |
| } |
| |
| @Override |
| public FieldInfos getFieldInfos() { |
| return in.getFieldInfos(); |
| } |
| |
| @Override |
| public PointsReader getPointsReader() { |
| return in.getPointsReader(); |
| } |
| |
| @Override |
| public int numDocs() { |
| return in.numDocs(); |
| } |
| |
| @Override |
| public int maxDoc() { |
| return in.maxDoc(); |
| } |
| |
| @Override |
| public LeafMetaData getMetaData() { |
| return in.getMetaData(); |
| } |
| |
| @Override |
| protected void doClose() throws IOException { |
| in.doClose(); |
| } |
| |
| @Override |
| public long ramBytesUsed() { |
| return in.ramBytesUsed(); |
| } |
| |
| @Override |
| public Collection<Accountable> getChildResources() { |
| return in.getChildResources(); |
| } |
| |
| @Override |
| public void checkIntegrity() throws IOException { |
| in.checkIntegrity(); |
| } |
| |
| /** Returns the wrapped {@link CodecReader}. */ |
| public CodecReader getDelegate() { |
| return in; |
| } |
| |
| /** |
| * Returns a filtered codec reader with the given live docs and numDocs. |
| */ |
| static FilterCodecReader wrapLiveDocs(CodecReader reader, Bits liveDocs, int numDocs) { |
| return new FilterCodecReader(reader) { |
| @Override |
| public CacheHelper getCoreCacheHelper() { |
| return reader.getCoreCacheHelper(); |
| } |
| @Override |
| public CacheHelper getReaderCacheHelper() { |
| return null; // we are altering live docs |
| } |
| @Override |
| public Bits getLiveDocs() { |
| return liveDocs; |
| } |
| @Override |
| public int numDocs() { |
| return numDocs; |
| } |
| }; |
| } |
| } |