/*
* $Id: MappedRandomAccessFile.java 4784 2011-03-15 08:33:00Z blowagie $
*
* This file is part of the iText (R) project.
* Copyright (c) 1998-2011 1T3XT BVBA
* Authors: Bruno Lowagie, Paulo Soares, et al.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License version 3
* as published by the Free Software Foundation with the addition of the
* following permission added to Section 15 as permitted in Section 7(a):
* FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY 1T3XT,
* 1T3XT DISCLAIMS THE WARRANTY OF NON INFRINGEMENT OF THIRD PARTY RIGHTS.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Affero General Public License for more details.
* You should have received a copy of the GNU Affero General Public License
* along with this program; if not, see http://www.gnu.org/licenses or write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA, 02110-1301 USA, or download the license from the following URL:
* http://itextpdf.com/terms-of-use/
*
* The interactive user interfaces in modified source and object code versions
* of this program must display Appropriate Legal Notices, as required under
* Section 5 of the GNU Affero General Public License.
*
* In accordance with Section 7(b) of the GNU Affero General Public License,
* a covered work must retain the producer line in every PDF that is created
* or manipulated using iText.
*
* You can be released from the requirements of the license by purchasing
* a commercial license. Buying such a license is mandatory as soon as you
* develop commercial activities involving the iText software without
* disclosing the source code of your own applications.
* These activities include: offering paid services to customers as an ASP,
* serving PDFs on the fly in a web application, shipping iText with a closed
* source product.
*
* For more information, please contact iText Software Corp. at this
* address: [email protected]
*/
package com.itextpdf.text.pdf;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.lang.reflect.Method;
import java.nio.BufferUnderflowException;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.security.AccessController;
import java.security.PrivilegedAction;
/**
* A {@link java.nio.MappedByteBuffer} wrapped as a {@link java.io.RandomAccessFile}
*
* @author Joakim Sandstroem
* Created on 6.9.2006
*/
public class MappedRandomAccessFile {
private MappedByteBuffer mappedByteBuffer = null;
private FileChannel channel = null;
/**
* Constructs a new MappedRandomAccessFile instance
* @param filename String
* @param mode String r, w or rw
* @throws FileNotFoundException
* @throws IOException
*/
public MappedRandomAccessFile(String filename, String mode)
throws FileNotFoundException, IOException {
if (mode.equals("rw"))
init(
new java.io.RandomAccessFile(filename, mode).getChannel(),
FileChannel.MapMode.READ_WRITE);
else
init(
new FileInputStream(filename).getChannel(),
FileChannel.MapMode.READ_ONLY);
}
/**
* initializes the channel and mapped bytebuffer
* @param channel FileChannel
* @param mapMode FileChannel.MapMode
* @throws IOException
*/
private void init(FileChannel channel, FileChannel.MapMode mapMode)
throws IOException {
this.channel = channel;
this.mappedByteBuffer = channel.map(mapMode, 0L, channel.size());
mappedByteBuffer.load();
}
/**
* @since 2.0.8
*/
public FileChannel getChannel() {
return channel;
}
/**
* @see java.io.RandomAccessFile#read()
* @return int next integer or -1 on EOF
*/
public int read() {
try {
byte b = mappedByteBuffer.get();
int n = b & 0xff;
return n;
} catch (BufferUnderflowException e) {
return -1; // EOF
}
}
/**
* @see java.io.RandomAccessFile#read(byte[], int, int)
* @param bytes byte[]
* @param off int offset
* @param len int length
* @return int bytes read or -1 on EOF
*/
public int read(byte bytes[], int off, int len) {
int pos = mappedByteBuffer.position();
int limit = mappedByteBuffer.limit();
if (pos == limit)
return -1; // EOF
int newlimit = pos + len - off;
if (newlimit > limit) {
len = limit - pos; // don't read beyond EOF
}
mappedByteBuffer.get(bytes, off, len);
return len;
}
/**
* @see java.io.RandomAccessFile#getFilePointer()
* @return long
*/
public long getFilePointer() {
return mappedByteBuffer.position();
}
/**
* @see java.io.RandomAccessFile#seek(long)
* @param pos long position
*/
public void seek(long pos) {
mappedByteBuffer.position((int) pos);
}
/**
* @see java.io.RandomAccessFile#length()
* @return long length
*/
public long length() {
return mappedByteBuffer.limit();
}
/**
* @see java.io.RandomAccessFile#close()
* Cleans the mapped bytebuffer and closes the channel
*/
public void close() throws IOException {
clean(mappedByteBuffer);
mappedByteBuffer = null;
if (channel != null)
channel.close();
channel = null;
}
/**
* invokes the close method
* @see java.lang.Object#finalize()
*/
@Override
protected void finalize() throws Throwable {
close();
super.finalize();
}
/**
* invokes the clean method on the ByteBuffer's cleaner
* @param buffer ByteBuffer
* @return boolean true on success
*/
public static boolean clean(final java.nio.ByteBuffer buffer) {
if (buffer == null || !buffer.isDirect())
return false;
Boolean b = (Boolean) AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
public Boolean run() {
Boolean success = Boolean.FALSE;
try {
Method getCleanerMethod = buffer.getClass().getMethod("cleaner", (Class<?>[])null);
getCleanerMethod.setAccessible(true);
Object cleaner = getCleanerMethod.invoke(buffer, (Object[])null);
Method clean = cleaner.getClass().getMethod("clean", (Class<?>[])null);
clean.invoke(cleaner, (Object[])null);
success = Boolean.TRUE;
} catch (Exception e) {
// This really is a show stopper on windows
//e.printStackTrace();
}
return success;
}
});
return b.booleanValue();
}
}
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