001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.io.hfile;
019
020import org.apache.hadoop.hbase.io.HeapSize;
021import org.apache.yetus.audience.InterfaceAudience;
022
023/**
024 * In-memory BlockCache that may be backed by secondary layer(s).
025 */
026@InterfaceAudience.Private
027public interface FirstLevelBlockCache extends ResizableBlockCache, HeapSize {
028
029  /**
030   * Whether the cache contains the block with specified cacheKey
031   * @param cacheKey cache key for the block
032   * @return true if it contains the block
033   */
034  boolean containsBlock(BlockCacheKey cacheKey);
035
036  /**
037   * Specifies the secondary cache. An entry that is evicted from this cache due to a size
038   * constraint will be inserted into the victim cache.
039   * @param victimCache the second level cache
040   * @throws IllegalArgumentException if the victim cache had already been set
041   */
042  void setVictimCache(BlockCache victimCache);
043}