| /** |
| * Copyright 2009 The Apache Software Foundation |
| * |
| * 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.hadoop.hbase.io; |
| |
| /** |
| * Implementations can be asked for an estimate of their size in bytes. |
| * <p> |
| * Useful for sizing caches. Its a given that implementation approximations |
| * do not account for 32 vs 64 bit nor for different VM implementations. |
| * <p> |
| * An Object's size is determined by the non-static data members in it, |
| * as well as the fixed {@link Object} overhead. |
| * <p> |
| * For example: |
| * <pre> |
| * public class SampleObject implements HeapSize { |
| * |
| * int [] numbers; |
| * int x; |
| * } |
| * </pre> |
| */ |
| public interface HeapSize { |
| /** |
| * @return Approximate 'exclusive deep size' of implementing object. Includes |
| * count of payload and hosting object sizings. |
| */ |
| public long heapSize(); |
| |
| } |
