| /* |
| * 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.lucene50; |
| |
| import java.io.IOException; |
| import org.apache.lucene.codecs.CodecUtil; |
| import org.apache.lucene.codecs.CompoundDirectory; |
| import org.apache.lucene.codecs.CompoundFormat; |
| import org.apache.lucene.index.SegmentInfo; |
| import org.apache.lucene.store.DataOutput; |
| import org.apache.lucene.store.Directory; |
| import org.apache.lucene.store.IOContext; |
| |
| /** |
| * Lucene 5.0 compound file format |
| * |
| * <p>Files: |
| * |
| * <ul> |
| * <li><code>.cfs</code>: An optional "virtual" file consisting of all the other index files for |
| * systems that frequently run out of file handles. |
| * <li><code>.cfe</code>: The "virtual" compound file's entry table holding all entries in the |
| * corresponding .cfs file. |
| * </ul> |
| * |
| * <p>Description: |
| * |
| * <ul> |
| * <li>Compound (.cfs) --> Header, FileData <sup>FileCount</sup>, Footer |
| * <li>Compound Entry Table (.cfe) --> Header, FileCount, <FileName, DataOffset, |
| * DataLength> <sup>FileCount</sup> |
| * <li>Header --> {@link CodecUtil#writeIndexHeader IndexHeader} |
| * <li>FileCount --> {@link DataOutput#writeVInt VInt} |
| * <li>DataOffset,DataLength,Checksum --> {@link DataOutput#writeLong UInt64} |
| * <li>FileName --> {@link DataOutput#writeString String} |
| * <li>FileData --> raw file data |
| * <li>Footer --> {@link CodecUtil#writeFooter CodecFooter} |
| * </ul> |
| * |
| * <p>Notes: |
| * |
| * <ul> |
| * <li>FileCount indicates how many files are contained in this compound file. The entry table |
| * that follows has that many entries. |
| * <li>Each directory entry contains a long pointer to the start of this file's data section, the |
| * files length, and a String with that file's name. |
| * </ul> |
| */ |
| public final class Lucene50CompoundFormat extends CompoundFormat { |
| |
| /** Extension of compound file */ |
| static final String DATA_EXTENSION = "cfs"; |
| /** Extension of compound file entries */ |
| static final String ENTRIES_EXTENSION = "cfe"; |
| |
| static final String DATA_CODEC = "Lucene50CompoundData"; |
| static final String ENTRY_CODEC = "Lucene50CompoundEntries"; |
| static final int VERSION_START = 0; |
| static final int VERSION_CURRENT = VERSION_START; |
| |
| /** Sole constructor. */ |
| public Lucene50CompoundFormat() {} |
| |
| @Override |
| public CompoundDirectory getCompoundReader(Directory dir, SegmentInfo si, IOContext context) |
| throws IOException { |
| return new Lucene50CompoundReader(dir, si, context); |
| } |
| |
| @Override |
| public void write(Directory dir, SegmentInfo si, IOContext context) throws IOException { |
| throw new UnsupportedOperationException("Old formats can't be used for writing"); |
| } |
| } |