| /* |
| * 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.sysds.runtime.controlprogram.caching; |
| |
| import java.lang.ref.SoftReference; |
| import java.util.HashMap; |
| import java.util.LinkedList; |
| |
| public class PageCache |
| { |
| private static final int CLEANUP_THRESHOLD = 128; |
| private static HashMap<Integer, LinkedList<SoftReference<byte[]>>> _pool; |
| |
| public static void init() { |
| _pool = new HashMap<>(); |
| } |
| |
| public static void clear() |
| { |
| _pool = null; |
| } |
| |
| public static void putPage( byte[] data ) |
| { |
| //cleanup if too many different size lists |
| if( _pool.size()>CLEANUP_THRESHOLD ) |
| _pool.clear(); |
| |
| LinkedList<SoftReference<byte[]>> list = _pool.get( data.length ); |
| if( list==null ){ |
| list = new LinkedList<>(); |
| _pool.put(data.length, list); |
| } |
| list.addLast(new SoftReference<>(data)); |
| } |
| |
| public static byte[] getPage( int size ) |
| { |
| LinkedList<SoftReference<byte[]>> list = _pool.get( size ); |
| if( list!=null ) { |
| while( !list.isEmpty() ){ |
| SoftReference<byte[]> ref = list.removeFirst(); |
| byte[] tmp = ref.get(); |
| if( tmp!=null ) |
| return tmp; |
| } |
| } |
| return null; |
| } |
| } |