ActiveMQ example source code file (DataFile.java)

This example ActiveMQ source code file (DataFile.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - ActiveMQ tags/keywords

datafile, file, filenotfoundexception, integer, integer, io, ioexception, ioexception, object, object, randomaccessfile, randomaccessfile, string

The ActiveMQ DataFile.java source code

/**
 * 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.activemq.kaha.impl.data;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;

/**
 * DataFile
 * 
 * 
 */
class DataFile {

    private final File file;
    private final Integer number;
    private int referenceCount;
    private RandomAccessFile randomAcessFile;
    private Object writerData;
    private long length;
    private boolean dirty;

    DataFile(File file, int number) {
        this.file = file;
        this.number = Integer.valueOf(number);
        length = file.exists() ? file.length() : 0;
    }

    Integer getNumber() {
        return number;
    }

    synchronized RandomAccessFile getRandomAccessFile() throws FileNotFoundException {
        if (randomAcessFile == null) {
            randomAcessFile = new RandomAccessFile(file, "rw");
        }
        return randomAcessFile;
    }

    synchronized long getLength() {
        return length;
    }

    synchronized void incrementLength(int size) {
        length += size;
    }

    synchronized void purge() throws IOException {
        if (randomAcessFile != null) {
            randomAcessFile.close();
            randomAcessFile = null;
        }
    }

    synchronized boolean delete() throws IOException {
        purge();
        return file.delete();
    }

    synchronized void close() throws IOException {
        if (randomAcessFile != null) {
            randomAcessFile.close();
        }
    }

    synchronized int increment() {
        return ++referenceCount;
    }

    synchronized int decrement() {
        return --referenceCount;
    }

    synchronized boolean isUnused() {
        return referenceCount <= 0;
    }

    public String toString() {
        String result = file.getName() + " number = " + number + " , length = " + length + " refCount = " + referenceCount;
        return result;
    }

    /**
     * @return Opaque data that a DataFileWriter may want to associate with the
     *         DataFile.
     */
    public synchronized Object getWriterData() {
        return writerData;
    }

    /**
     * @param writerData - Opaque data that a DataFileWriter may want to
     *                associate with the DataFile.
     */
    public synchronized void setWriterData(Object writerData) {
        this.writerData = writerData;
        dirty = true;
    }

    public synchronized boolean isDirty() {
        return dirty;
    }

    public synchronized void setDirty(boolean value) {
        this.dirty = value;
    }

}