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}