| /* |
| * 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.search; |
| |
| import java.io.IOException; |
| |
| /** |
| * A policy defining which filters should be cached. |
| * |
| * <p>Implementations of this class must be thread-safe. |
| * |
| * @see UsageTrackingQueryCachingPolicy |
| * @see LRUQueryCache |
| * @lucene.experimental |
| */ |
| // TODO: add APIs for integration with IndexWriter.IndexReaderWarmer |
| public interface QueryCachingPolicy { |
| |
| /** |
| * Callback that is called every time that a cached filter is used. This is typically useful if |
| * the policy wants to track usage statistics in order to make decisions. |
| */ |
| void onUse(Query query); |
| |
| /** |
| * Whether the given {@link Query} is worth caching. This method will be called by the {@link |
| * QueryCache} to know whether to cache. It will first attempt to load a {@link DocIdSet} from the |
| * cache. If it is not cached yet and this method returns <code>true</code> then a cache entry |
| * will be generated. Otherwise an uncached scorer will be returned. |
| */ |
| boolean shouldCache(Query query) throws IOException; |
| } |