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.Closeable;
import java.io.IOException;
/** <p>Expert: {@link IndexWriter} uses an instance
* implementing this interface to execute the merges
* selected by a {@link MergePolicy}. The default
* MergeScheduler is {@link ConcurrentMergeScheduler}.</p>
* <p>Implementers of sub-classes should make sure that {@link #clone()}
* returns an independent instance able to work with any {@link IndexWriter}
* instance.</p>
* @lucene.experimental
*/
public abstract class MergeScheduler implements Closeable, Cloneable {
/** Sole constructor. (For invocation by subclass
* constructors, typically implicit.) */
protected MergeScheduler() {
}
/** Run the merges provided by {@link IndexWriter#getNextMerge()}.
* @param writer the {@link IndexWriter} to obtain the merges from.
* @param trigger the {@link MergeTrigger} that caused this merge to happen
* @param newMergesFound <code>true</code> iff any new merges were found by the caller otherwise <code>false</code>
* */
public abstract void merge(IndexWriter writer, MergeTrigger trigger, boolean newMergesFound) throws IOException;
/** Close this MergeScheduler. */
@Override
public abstract void close() throws IOException;
@Override
public MergeScheduler clone() {
try {
return (MergeScheduler) super.clone();
} catch (CloneNotSupportedException e) {
throw new Error(e);
}
}
}