| 1 | /******************************************************************************* |
| 2 | * Copyright (c) 2014 Ericsson |
| 3 | * |
| 4 | * All rights reserved. This program and the accompanying materials are made |
| 5 | * available under the terms of the Eclipse Public License v1.0 which |
| 6 | * accompanies this distribution, and is available at |
| 7 | * http://www.eclipse.org/legal/epl-v10.html |
| 8 | * |
| 9 | * Contributors: |
| 10 | * Marc-Andre Laperle - Initial API and implementation |
| 11 | *******************************************************************************/ |
| 12 | |
| 13 | package org.eclipse.linuxtools.internal.ctf.core; |
| 14 | |
| 15 | import java.io.IOException; |
| 16 | import java.nio.ByteBuffer; |
| 17 | import java.nio.channels.FileChannel; |
| 18 | |
| 19 | /** |
| 20 | * A common utility for mapping a ByteBuffer safely to work around a bug on |
| 21 | * Windows which prevents deleting a file after it was mapped. On Windows, the |
| 22 | * ByteBuffer will be allocated and the file will be read instead of being |
| 23 | * mapped. |
| 24 | * |
| 25 | * http://bugs.java.com/view_bug.do?bug_id=4715154 |
| 26 | */ |
| 27 | public class SafeMappedByteBuffer { |
| 28 | |
| 29 | private static final boolean IS_WIN32 = System.getProperty("os.name").startsWith("Windows"); //$NON-NLS-1$//$NON-NLS-2$ |
| 30 | |
| 31 | /** |
| 32 | * Maps a region of this channel's file directly into memory. On Windows, |
| 33 | * this will allocate a new ByteBuffer and read the file. |
| 34 | * |
| 35 | * @param fc |
| 36 | * the file channel |
| 37 | * @param mode |
| 38 | * the mapping mode |
| 39 | * @param position |
| 40 | * the position within the file |
| 41 | * @param size |
| 42 | * the size of the region to be mapped (or read) |
| 43 | * @return the mapped ByteBuffer |
| 44 | * @throws IOException |
| 45 | * on FileChannel operations failures |
| 46 | */ |
| 47 | public static ByteBuffer map(FileChannel fc, FileChannel.MapMode mode, long position, long size) throws IOException { |
| 48 | ByteBuffer byteBuffer; |
| 49 | if (IS_WIN32) { |
| 50 | byteBuffer = ByteBuffer.allocate((int) size); |
| 51 | fc.read(byteBuffer, position); |
| 52 | } else { |
| 53 | byteBuffer = fc.map(mode, position, size); |
| 54 | } |
| 55 | |
| 56 | return byteBuffer; |
| 57 | } |
| 58 | } |