| 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.Map; |
| |
| |
| /** |
| * A {@link MergePolicy} which never returns merges to execute (hence it's |
| * name). It is also a singleton and can be accessed through |
| * {@link NoMergePolicy#NO_COMPOUND_FILES} if you want to indicate the index |
| * does not use compound files, or through {@link NoMergePolicy#COMPOUND_FILES} |
| * otherwise. Use it if you want to prevent an {@link IndexWriter} from ever |
| * executing merges, without going through the hassle of tweaking a merge |
| * policy's settings to achieve that, such as changing its merge factor. |
| */ |
| public final class NoMergePolicy extends MergePolicy { |
| |
| /** |
| * A singleton {@link NoMergePolicy} which indicates the index does not use |
| * compound files. |
| */ |
| public static final MergePolicy NO_COMPOUND_FILES = new NoMergePolicy(false); |
| |
| /** |
| * A singleton {@link NoMergePolicy} which indicates the index uses compound |
| * files. |
| */ |
| public static final MergePolicy COMPOUND_FILES = new NoMergePolicy(true); |
| |
| private final boolean useCompoundFile; |
| |
| private NoMergePolicy(boolean useCompoundFile) { |
| super(useCompoundFile ? 1.0 : 0.0, 0); |
| // prevent instantiation |
| this.useCompoundFile = useCompoundFile; |
| } |
| |
| @Override |
| public void close() {} |
| |
| @Override |
| public MergeSpecification findMerges(MergeTrigger mergeTrigger, SegmentInfos segmentInfos) { return null; } |
| |
| @Override |
| public MergeSpecification findForcedMerges(SegmentInfos segmentInfos, |
| int maxSegmentCount, Map<SegmentInfoPerCommit,Boolean> segmentsToMerge) { return null; } |
| |
| @Override |
| public MergeSpecification findForcedDeletesMerges(SegmentInfos segmentInfos) { return null; } |
| |
| @Override |
| public boolean useCompoundFile(SegmentInfos segments, SegmentInfoPerCommit newSegment) { return useCompoundFile; } |
| |
| @Override |
| public void setIndexWriter(IndexWriter writer) {} |
| |
| @Override |
| protected long size(SegmentInfoPerCommit info) throws IOException { |
| return Long.MAX_VALUE; |
| } |
| |
| @Override |
| public String toString() { |
| return "NoMergePolicy"; |
| } |
| } |