001/** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.activemq.kaha.impl.async; 018 019import java.io.File; 020import java.io.IOException; 021import java.io.RandomAccessFile; 022 023import org.apache.activemq.util.IOHelper; 024 025/** 026 * Allows you to open a data file in read only mode. Useful when working with 027 * archived data files. 028 */ 029public class ReadOnlyDataFile extends DataFile { 030 031 ReadOnlyDataFile(File file, int number, int preferedSize) { 032 super(file, number, preferedSize); 033 } 034 035 036 public RandomAccessFile openRandomAccessFile(boolean appender) throws IOException { 037 RandomAccessFile rc = new RandomAccessFile(file, "r"); 038 // When we start to write files size them up so that the OS has a chance 039 // to allocate the file contigously. 040 if (appender) { 041 if (length < preferedSize) { 042 rc.setLength(preferedSize); 043 } 044 } 045 return rc; 046 } 047 048 public void closeRandomAccessFile(RandomAccessFile file) throws IOException { 049 file.close(); 050 } 051 052 public synchronized boolean delete() throws IOException { 053 throw new RuntimeException("Not valid on a read only file."); 054 } 055 056 public synchronized void move(File targetDirectory) throws IOException{ 057 throw new RuntimeException("Not valid on a read only file."); 058 } 059 060}