org.netbeans.modules.schema2beansdev.gen.WriteIfDifferentOutputStream Maven / Gradle / Ivy
The newest version!
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 1997-2010 Oracle and/or its affiliates. All rights reserved.
*
* Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common
* Development and Distribution License("CDDL") (collectively, the
* "License"). You may not use this file except in compliance with the
* License. You can obtain a copy of the License at
* http://www.netbeans.org/cddl-gplv2.html
* or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
* specific language governing permissions and limitations under the
* License. When distributing the software, include this License Header
* Notice in each file and include the License file at
* nbbuild/licenses/CDDL-GPL-2-CP. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the GPL Version 2 section of the License file that
* accompanied this code. If applicable, add the following below the
* License Header, with the fields enclosed by brackets [] replaced by
* your own identifying information:
* "Portions Copyrighted [year] [name of copyright owner]"
*
* Contributor(s):
*
* The Original Software is NetBeans. The Initial Developer of the Original
* Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
* Microsystems, Inc. All Rights Reserved.
*
* If you wish your version of this file to be governed by only the CDDL
* or only the GPL Version 2, indicate your decision by adding
* "[Contributor] elects to include this software in this distribution
* under the [CDDL or GPL Version 2] license." If you do not indicate a
* single choice of license, a recipient has the option to distribute
* your version of this file under either the CDDL, the GPL Version 2 or
* to extend the choice of license to its licensees as provided above.
* However, if you add GPL Version 2 code and therefore, elected the GPL
* Version 2 license, then the option applies only if the new code is
* made subject to such option by the copyright holder.
*/
package org.netbeans.modules.schema2beansdev.gen;
import java.util.*;
import java.io.*;
public class WriteIfDifferentOutputStream extends OutputStream {
private RandomAccessFile randFile;
private long initialRandFileLength;
private boolean justWrite = false;
public WriteIfDifferentOutputStream(RandomAccessFile randFile) throws IOException {
this.randFile = randFile;
this.initialRandFileLength = randFile.length();
}
public WriteIfDifferentOutputStream(String filename) throws IOException {
this(new RandomAccessFile(filename, "rw")); // NOI18N
}
public WriteIfDifferentOutputStream(File file) throws IOException {
this(new RandomAccessFile(file, "rw")); // NOI18N
}
public void write(int b) throws IOException {
if (justWrite) {
randFile.write(b);
return;
}
long fp = randFile.getFilePointer();
if (fp + 1 > initialRandFileLength) {
justWrite = true;
randFile.write(b);
return;
}
int fromFile = randFile.read();
if (fromFile != b) {
//System.out.println("different: fromFile="+fromFile+" b="+b);
randFile.seek(fp);
randFile.write(b);
justWrite = true;
return;
}
}
private byte[] writeBuf;
private int lastLen = -1;
public void write(byte[] b, int off, int len) throws IOException {
if (justWrite) {
randFile.write(b, off, len);
return;
}
long fp = randFile.getFilePointer();
if (fp + len > initialRandFileLength) {
justWrite = true;
randFile.write(b, off, len);
return;
}
if (len > lastLen) {
// Allocate a new buffer only if the last one wasn't big enough.
writeBuf = new byte[len];
lastLen = len;
}
randFile.read(writeBuf, 0, len);
for (int i = off, j = 0; j < len; ++i, ++j) {
if (writeBuf[j] != b[i]) {
//System.out.println("different: i="+i+" j="+j);
randFile.seek(fp);
randFile.write(b, off, len);
justWrite = true;
return;
}
}
}
/*
public void flush() throws IOException {
randFile.flush();
}
*/
/**
* At this point, have we changed the file?
* It's possible to not change a file until close() is called.
*/
public boolean isChanged() {
return justWrite;
}
public void close() throws IOException {
// Truncate it.
//System.out.println("truncating to "+randFile.getFilePointer());
if (randFile.getFilePointer() < randFile.length()) {
justWrite = true;
randFile.setLength(randFile.getFilePointer());
}
randFile.close();
}
}