/*
 * Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0, which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package org.jvnet.mimepull;

import java.io.*;

Use RandomAccessFile for concurrent access of read and write partial part's content. 
Author:
Kohsuke Kawaguchi, Jitendra Kotamraju/**
 * Use {@link RandomAccessFile} for concurrent access of read
 * and write partial part's content.
 *
 * @author Kohsuke Kawaguchi
 * @author Jitendra Kotamraju
 */
final class DataFile {
    private WeakDataFile weak;
    private long writePointer;

    DataFile(File file) {
        writePointer=0;
        weak = new WeakDataFile(this, file);
    }

    /**
     *
     */
    void close() {
        weak.close();
    }

    
Read data from the given file pointer position.
Params:
pointer – read position
buf – that needs to be filled
offset – the start offset of the data.
length – of data that needs to be read/**
     * Read data from the given file pointer position.
     *
     * @param pointer read position
     * @param buf that needs to be filled
     * @param offset the start offset of the data.
     * @param length of data that needs to be read
     */
    synchronized void read(long pointer, byte[] buf, int offset, int length ) {
        weak.read(pointer, buf, offset, length);
    }

    void renameTo(File f) {
        weak.renameTo(f);
    }

    
Write data to the file
Params:
data – that needs to written to a file
offset – start offset in the data
length – no bytes to write
Returns:
file pointer before the write operation(or at which the
        data is written)/**
     * Write data to the file
     *
     * @param data that needs to written to a file
     * @param offset start offset in the data
     * @param length no bytes to write
     * @return file pointer before the write operation(or at which the
     *         data is written)
     */
    synchronized long writeTo(byte[] data, int offset, int length) {
        long temp = writePointer;
        writePointer = weak.writeTo(writePointer, data, offset, length);
        return temp;
    }

}