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. Use it if you
   * want to prevent segment merges.
   */
  public final class NoMergePolicy extends MergePolicy {
  
    /** Singleton instance. */
    public static final MergePolicy INSTANCE = new NoMergePolicy();
  
    private NoMergePolicy() {
      super();
    }
  
    @Override
    public MergeSpecification findMerges(MergeTrigger mergeTrigger, SegmentInfos segmentInfos, IndexWriter writer) { return null; }
  
    @Override
    public MergeSpecification findForcedMerges(SegmentInfos segmentInfos,
               int maxSegmentCount, Map<SegmentCommitInfo,Boolean> segmentsToMerge, IndexWriter writer) { return null; }
  
    @Override
    public MergeSpecification findForcedDeletesMerges(SegmentInfos segmentInfos, IndexWriter writer) { return null; }
  
    @Override
    public boolean useCompoundFile(SegmentInfos segments, SegmentCommitInfo newSegment, IndexWriter writer) {
      return newSegment.info.getUseCompoundFile();
    }
  
    @Override
    protected long size(SegmentCommitInfo info, IndexWriter writer) throws IOException {
      return Long.MAX_VALUE;
    }
  
    @Override
    public String toString() {
      return "NoMergePolicy";
    }
  }