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.bucket; 019 020import java.io.IOException; 021import org.apache.hadoop.hbase.io.hfile.Cacheable; 022import org.apache.hadoop.hbase.nio.ByteBuff; 023import org.apache.yetus.audience.InterfaceAudience; 024 025/** 026 * IO engine that stores data to a file on the local block device using memory mapping mechanism 027 */ 028@InterfaceAudience.Private 029public class ExclusiveMemoryMmapIOEngine extends FileMmapIOEngine { 030 031 public ExclusiveMemoryMmapIOEngine(String filePath, long capacity) throws IOException { 032 super(filePath, capacity); 033 } 034 035 @Override 036 public Cacheable read(BucketEntry be) throws IOException { 037 ByteBuff dst = be.allocator.allocate(be.getLength()); 038 bufferArray.read(be.offset(), dst); 039 dst.position(0).limit(be.getLength()); 040 return be.wrapAsCacheable(dst); 041 } 042}