| /******************************************************************************* |
| * Copyright (c) 2003, 2006 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| |
| package org.eclipse.osgi.framework.internal.reliablefile; |
| |
| import java.io.*; |
| import java.util.zip.Checksum; |
| |
| /** |
| * A ReliableFile FileOutputStream replacement class. |
| * This class can be used just like FileOutputStream. The class |
| * is in partnership with ReliableFileInputStream to avoid losing |
| * file data by using multiple files. |
| * |
| * @see ReliableFileInputStream |
| */ |
| public class ReliableFileOutputStream extends FilterOutputStream { |
| /** |
| * ReliableFile object for the file. |
| */ |
| private ReliableFile reliable; |
| |
| /** |
| * Checksum calculator |
| */ |
| private Checksum crc; |
| |
| private boolean outputOpen = false; |
| |
| /** |
| * Constructs a new ReliableFileOutputStream on the File <code>file</code>. If the |
| * file exists, it is written over. See the constructor which can append to |
| * the file if so desired. |
| * |
| * @param file the File on which to stream reads. |
| * @exception java.io.IOException If an error occurs opening the file. |
| */ |
| public ReliableFileOutputStream(File file) throws IOException { |
| this(ReliableFile.getReliableFile(file), false); |
| } |
| |
| /** |
| * Constructs a new ReliableFileOutputStream on the File <code>file</code>. |
| * |
| * @param file the File on which to stream reads. |
| * @param append a boolean indicating whether or not to append to an existing file. |
| * @exception java.io.IOException If an error occurs opening the file. |
| */ |
| public ReliableFileOutputStream(File file, boolean append) throws IOException { |
| this(ReliableFile.getReliableFile(file), append); |
| } |
| |
| /** |
| * Constructs a new ReliableFileOutputStream on the file named <code>name</code>. If |
| * the file exists, it is written over. See the constructor which can append to |
| * the file if so desired. |
| * The <code>name</code> may be absolute or relative |
| * to the System property <code>"user.dir"</code>. |
| * |
| * @param name the file on which to stream writes. |
| * @exception java.io.IOException If an error occurs opening the file. |
| */ |
| public ReliableFileOutputStream(String name) throws IOException { |
| this(ReliableFile.getReliableFile(name), false); |
| } |
| |
| /** |
| * Constructs a new ReliableFileOutputStream on the file named <code>name</code>. |
| * The <code>name</code> may be absolute or relative |
| * to the System property <code>"user.dir"</code>. |
| * |
| * @param name the file on which to stream writes. |
| * @param append a boolean indicating whether or not to append to an existing file. |
| * @exception java.io.IOException If an error occurs opening the file. |
| */ |
| public ReliableFileOutputStream(String name, boolean append) throws IOException { |
| this(ReliableFile.getReliableFile(name), append); |
| } |
| |
| /** |
| * Private constructor used by other constructors. |
| * |
| * @param reliable the ReliableFile on which to read. |
| * @param append a boolean indicating whether or not to append to an existing file. |
| * @exception java.io.IOException If an error occurs opening the file. |
| */ |
| private ReliableFileOutputStream(ReliableFile reliable, boolean append) throws IOException { |
| super(reliable.getOutputStream(append, ReliableFile.GENERATION_LATEST)); |
| |
| this.reliable = reliable; |
| outputOpen = true; |
| if (append) |
| crc = reliable.getFileChecksum(); |
| else |
| crc = reliable.getChecksumCalculator(); |
| } |
| |
| /** |
| * Closes this output stream and releases any system resources |
| * associated with this stream. The general contract of <code>close</code> |
| * is that it closes the output stream. A closed stream cannot perform |
| * output operations and cannot be reopened. |
| * |
| * @exception java.io.IOException If an error occurs closing the file. |
| */ |
| public synchronized void close() throws IOException { |
| closeIntermediateFile(); |
| reliable.closeOutputFile(crc); |
| // if the previouse closeOutpuFile() throws exception, |
| // we don't null out reliable to give another opportunity |
| // to rename the file. |
| reliable = null; |
| } |
| |
| public File closeIntermediateFile() throws IOException { |
| if (reliable == null) |
| throw new IOException("ReliableFile stream not open"); //$NON-NLS-1$ |
| if (outputOpen) { |
| // tag on our signature and checksum |
| reliable.writeChecksumSignature(out, crc); |
| out.flush(); |
| try { |
| ((FileOutputStream) out).getFD().sync(); |
| } catch (IOException e) { |
| // just ignore this Exception |
| //Debug |
| e.printStackTrace(); |
| } |
| out.close(); |
| outputOpen = false; |
| } |
| return reliable.getOutputFile(); |
| } |
| |
| /** |
| * Override default FilterOutputStream method. |
| * @see FilterOutputStream#write(byte[]) |
| */ |
| public void write(byte[] b) throws IOException { |
| this.write(b, 0, b.length); |
| } |
| |
| /** |
| * Override default FilterOutputStream method. |
| * @see FilterOutputStream#write(byte[], int, int) |
| */ |
| public void write(byte[] b, int off, int len) throws IOException { |
| out.write(b, off, len); |
| crc.update(b, off, len); |
| } |
| |
| /** |
| * Override default FilterOutputStream method. |
| * @see FilterOutputStream#write(int) |
| */ |
| public void write(int b) throws IOException { |
| out.write(b); |
| crc.update((byte) b); |
| } |
| |
| public void abort() { |
| if (reliable == null) |
| return; |
| if (outputOpen) { |
| try { |
| out.close(); |
| } catch (IOException e) {/*ignore*/ |
| } |
| outputOpen = false; |
| } |
| reliable.abortOutputFile(); |
| reliable = null; |
| } |
| } |