| package org.apache.lucene.codecs.lucene42; |
| |
| /* |
| * 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 org.apache.lucene.codecs.DocValuesConsumer; |
| import org.apache.lucene.codecs.DocValuesProducer; |
| import org.apache.lucene.codecs.NormsFormat; |
| import org.apache.lucene.index.SegmentReadState; |
| import org.apache.lucene.index.SegmentWriteState; |
| import org.apache.lucene.util.packed.PackedInts; |
| |
| /** |
| * Lucene 4.2 score normalization format. |
| * <p> |
| * NOTE: this uses the same format as {@link Lucene42DocValuesFormat} |
| * Numeric DocValues, but with different file extensions, and passing |
| * {@link PackedInts#FASTEST} for uncompressed encoding: trading off |
| * space for performance. |
| * <p> |
| * Files: |
| * <ul> |
| * <li><tt>.nvd</tt>: DocValues data</li> |
| * <li><tt>.nvm</tt>: DocValues metadata</li> |
| * </ul> |
| * @see Lucene42DocValuesFormat |
| */ |
| public class Lucene42NormsFormat extends NormsFormat { |
| final float acceptableOverheadRatio; |
| |
| /** |
| * Calls {@link #Lucene42NormsFormat(float) |
| * Lucene42DocValuesFormat(PackedInts.FASTEST)} |
| */ |
| public Lucene42NormsFormat() { |
| // note: we choose FASTEST here (otherwise our norms are half as big but 15% slower than previous lucene) |
| this(PackedInts.FASTEST); |
| } |
| |
| /** |
| * Creates a new Lucene42DocValuesFormat with the specified |
| * <code>acceptableOverheadRatio</code> for NumericDocValues. |
| * @param acceptableOverheadRatio compression parameter for numerics. |
| * Currently this is only used when the number of unique values is small. |
| * |
| * @lucene.experimental |
| */ |
| public Lucene42NormsFormat(float acceptableOverheadRatio) { |
| this.acceptableOverheadRatio = acceptableOverheadRatio; |
| } |
| |
| @Override |
| public DocValuesConsumer normsConsumer(SegmentWriteState state) throws IOException { |
| throw new UnsupportedOperationException("this codec can only be used for reading"); |
| } |
| |
| @Override |
| public DocValuesProducer normsProducer(SegmentReadState state) throws IOException { |
| return new Lucene42DocValuesProducer(state, DATA_CODEC, DATA_EXTENSION, METADATA_CODEC, METADATA_EXTENSION); |
| } |
| |
| static final String DATA_CODEC = "Lucene41NormsData"; |
| static final String DATA_EXTENSION = "nvd"; |
| static final String METADATA_CODEC = "Lucene41NormsMetadata"; |
| static final String METADATA_EXTENSION = "nvm"; |
| } |