/*
* $Id: MappedRandomAccessFile.java 5075 2012-02-27 16:36:18Z blowagie $
*
* This file is part of the iText (R) project.
* Copyright (c) 1998-2012 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: sales@itextpdf.com
*/
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 static final int BUFSIZE = 1 << 30;
private FileChannel channel = null;
private MappedByteBuffer[] mappedBuffers;
private long size;
private long pos;
/**
* 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;
size = channel.size();
pos = 0;
int requiredBuffers = (int)(size/BUFSIZE) + (size % BUFSIZE == 0 ? 0 : 1);
//System.out.println("This will require " + requiredBuffers + " buffers");
mappedBuffers = new MappedByteBuffer[requiredBuffers];
try{
int index = 0;
for(long offset = 0; offset < size; offset += BUFSIZE){
long size2 = Math.min(size - offset, BUFSIZE);
mappedBuffers[index] = channel.map(mapMode, offset, size2);
mappedBuffers[index].load();
index++;
}
if (index != requiredBuffers){
throw new Error("Should never happen - " + index + " != " + requiredBuffers);
}
} catch (IOException e){
close();
throw e;
} catch (RuntimeException e){
close();
throw e;
}
}
/**
* @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 {
int mapN = (int) (pos / BUFSIZE);
int offN = (int) (pos % BUFSIZE);
if (mapN >= mappedBuffers.length) // we have run out of data to read from
return -1;
if (offN >= mappedBuffers[mapN].limit())
return -1;
byte b = mappedBuffers[mapN].get(offN);
pos++;
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 mapN = (int) (pos / BUFSIZE);
int offN = (int) (pos % BUFSIZE);
int totalRead = 0;
while(totalRead < len){
if (mapN > mappedBuffers.length) // we have run out of data to read from
break;
MappedByteBuffer currentBuffer = mappedBuffers[mapN];
if (offN > currentBuffer.limit())
break;
currentBuffer.position(offN);
int bytesFromThisBuffer = Math.min(len, currentBuffer.remaining());
currentBuffer.get(bytes, off, bytesFromThisBuffer);
off += bytesFromThisBuffer;
pos += bytesFromThisBuffer;
totalRead += bytesFromThisBuffer;
mapN++;
offN = 0;
}
return totalRead == 0 ? -1 : totalRead;
}
/**
* @see java.io.RandomAccessFile#getFilePointer()
* @return long
*/
public long getFilePointer() {
return pos;
}
/**
* @see java.io.RandomAccessFile#seek(long)
* @param pos long position
*/
public void seek(long pos) {
this.pos = pos;
}
/**
* @see java.io.RandomAccessFile#length()
* @return long length
*/
public long length() {
return size;
}
/**
* @see java.io.RandomAccessFile#close()
* Cleans the mapped bytebuffer and closes the channel
*/
public void close() throws IOException {
for(int i = 0; i < mappedBuffers.length; i++){
if (mappedBuffers[i] != null){
clean(mappedBuffers[i]);
mappedBuffers[i] = 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();
}
}