1 /** 2 * Copyright 2011 The Apache Software Foundation 3 * 4 * Licensed to the Apache Software Foundation (ASF) under one 5 * or more contributor license agreements. See the NOTICE file 6 * distributed with this work for additional information 7 * regarding copyright ownership. The ASF licenses this file 8 * to you under the Apache License, Version 2.0 (the 9 * "License"); you may not use this file except in compliance 10 * with the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, software 15 * distributed under the License is distributed on an "AS IS" BASIS, 16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 17 * See the License for the specific language governing permissions and 18 * limitations under the License. 19 */ 20 21 package org.apache.hadoop.hbase.io.hfile.slab; 22 23 import org.apache.hadoop.hbase.io.hfile.BlockCacheKey; 24 25 /** 26 * Interface for objects that want to know when actions occur in a SingleSizeCache. 27 * */ 28 interface SlabItemActionWatcher { 29 30 /** 31 * This is called as a callback when an item is removed from a SingleSizeCache. 32 * 33 * @param key the key of the item being evicted 34 * @param notifier the object notifying the SlabCache of the eviction. 35 */ 36 void onEviction(BlockCacheKey key, SingleSizeCache notifier); 37 38 /** 39 * This is called as a callback when an item is inserted into a SingleSizeCache. 40 * 41 * @param key the key of the item being added 42 * @param notifier the object notifying the SlabCache of the insertion.. 43 */ 44 void onInsertion(BlockCacheKey key, SingleSizeCache notifier); 45 }