| /* |
| * 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.backward_codecs.lucene80; |
| |
| import java.io.IOException; |
| import org.apache.lucene.codecs.CodecUtil; |
| import org.apache.lucene.codecs.NormsConsumer; |
| import org.apache.lucene.codecs.NormsFormat; |
| import org.apache.lucene.codecs.NormsProducer; |
| import org.apache.lucene.index.SegmentReadState; |
| import org.apache.lucene.index.SegmentWriteState; |
| import org.apache.lucene.store.DataOutput; |
| |
| /** |
| * Lucene 8.0 Score normalization format. |
| * |
| * <p>Encodes normalization values by encoding each value with the minimum number of bytes needed to |
| * represent the range (which can be zero). |
| * |
| * <p>Files: |
| * |
| * <ol> |
| * <li><code>.nvd</code>: Norms data |
| * <li><code>.nvm</code>: Norms metadata |
| * </ol> |
| * |
| * <ol> |
| * <li><a id="nvm"></a> |
| * <p>The Norms metadata or .nvm file. |
| * <p>For each norms field, this stores metadata, such as the offset into the Norms data |
| * (.nvd) |
| * <p>Norms metadata (.dvm) --> Header,<Entry><sup>NumFields</sup>,Footer |
| * <ul> |
| * <li>Header --> {@link CodecUtil#writeIndexHeader IndexHeader} |
| * <li>Entry --> FieldNumber, DocsWithFieldAddress, DocsWithFieldLength, |
| * NumDocsWithField, BytesPerNorm, NormsAddress |
| * <li>FieldNumber --> {@link DataOutput#writeInt Int32} |
| * <li>DocsWithFieldAddress --> {@link DataOutput#writeLong Int64} |
| * <li>DocsWithFieldLength --> {@link DataOutput#writeLong Int64} |
| * <li>NumDocsWithField --> {@link DataOutput#writeInt Int32} |
| * <li>BytesPerNorm --> {@link DataOutput#writeByte byte} |
| * <li>NormsAddress --> {@link DataOutput#writeLong Int64} |
| * <li>Footer --> {@link CodecUtil#writeFooter CodecFooter} |
| * </ul> |
| * <p>FieldNumber of -1 indicates the end of metadata. |
| * <p>NormsAddress is the pointer to the start of the data in the norms data (.nvd), or the |
| * singleton value when BytesPerValue = 0. If BytesPerValue is different from 0 then there are |
| * NumDocsWithField values to read at that offset. |
| * <p>DocsWithFieldAddress is the pointer to the start of the bit set containing documents |
| * that have a norm in the norms data (.nvd), or -2 if no documents have a norm value, or -1 |
| * if all documents have a norm value. |
| * <p>DocsWithFieldLength is the number of bytes used to encode the set of documents that have |
| * a norm. |
| * <li><a id="nvd"></a> |
| * <p>The Norms data or .nvd file. |
| * <p>For each Norms field, this stores the actual per-document data (the heavy-lifting) |
| * <p>Norms data (.nvd) --> Header,< Data ><sup>NumFields</sup>,Footer |
| * <ul> |
| * <li>Header --> {@link CodecUtil#writeIndexHeader IndexHeader} |
| * <li>DocsWithFieldData --> {@link IndexedDISI#writeBitSet Bit set of MaxDoc bits} |
| * <li>NormsData --> {@link DataOutput#writeByte(byte) byte}<sup>NumDocsWithField * |
| * BytesPerValue</sup> |
| * <li>Footer --> {@link CodecUtil#writeFooter CodecFooter} |
| * </ul> |
| * </ol> |
| * |
| * @lucene.experimental |
| */ |
| public class Lucene80NormsFormat extends NormsFormat { |
| |
| /** Sole Constructor */ |
| public Lucene80NormsFormat() {} |
| |
| @Override |
| public NormsConsumer normsConsumer(SegmentWriteState state) throws IOException { |
| throw new UnsupportedOperationException("Old codecs may only be used for reading"); |
| } |
| |
| @Override |
| public NormsProducer normsProducer(SegmentReadState state) throws IOException { |
| return new Lucene80NormsProducer( |
| state, DATA_CODEC, DATA_EXTENSION, METADATA_CODEC, METADATA_EXTENSION); |
| } |
| |
| static final String DATA_CODEC = "Lucene80NormsData"; |
| static final String DATA_EXTENSION = "nvd"; |
| static final String METADATA_CODEC = "Lucene80NormsMetadata"; |
| static final String METADATA_EXTENSION = "nvm"; |
| static final int VERSION_START = 0; |
| static final int VERSION_CURRENT = VERSION_START; |
| } |
