001: /*
002: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
003: *
004: * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
005: *
006: * The contents of this file are subject to the terms of either the GNU
007: * General Public License Version 2 only ("GPL") or the Common
008: * Development and Distribution License("CDDL") (collectively, the
009: * "License"). You may not use this file except in compliance with the
010: * License. You can obtain a copy of the License at
011: * http://www.netbeans.org/cddl-gplv2.html
012: * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
013: * specific language governing permissions and limitations under the
014: * License. When distributing the software, include this License Header
015: * Notice in each file and include the License file at
016: * nbbuild/licenses/CDDL-GPL-2-CP. Sun designates this
017: * particular file as subject to the "Classpath" exception as provided
018: * by Sun in the GPL Version 2 section of the License file that
019: * accompanied this code. If applicable, add the following below the
020: * License Header, with the fields enclosed by brackets [] replaced by
021: * your own identifying information:
022: * "Portions Copyrighted [year] [name of copyright owner]"
023: *
024: * Contributor(s):
025: *
026: * The Original Software is NetBeans. The Initial Developer of the Original
027: * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
028: * Microsystems, Inc. All Rights Reserved.
029: *
030: * If you wish your version of this file to be governed by only the CDDL
031: * or only the GPL Version 2, indicate your decision by adding
032: * "[Contributor] elects to include this software in this distribution
033: * under the [CDDL or GPL Version 2] license." If you do not indicate a
034: * single choice of license, a recipient has the option to distribute
035: * your version of this file under either the CDDL, the GPL Version 2 or
036: * to extend the choice of license to its licensees as provided above.
037: * However, if you add GPL Version 2 code and therefore, elected the GPL
038: * Version 2 license, then the option applies only if the new code is
039: * made subject to such option by the copyright holder.
040: */
041:
042: package org.netbeans.modules.schema2beansdev.gen;
043:
044: import java.util.*;
045: import java.io.*;
046:
047: public class WriteIfDifferentOutputStream extends OutputStream {
048: private RandomAccessFile randFile;
049: private long initialRandFileLength;
050: private boolean justWrite = false;
051:
052: public WriteIfDifferentOutputStream(RandomAccessFile randFile)
053: throws IOException {
054: this .randFile = randFile;
055: this .initialRandFileLength = randFile.length();
056: }
057:
058: public WriteIfDifferentOutputStream(String filename)
059: throws IOException {
060: this (new RandomAccessFile(filename, "rw")); // NOI18N
061: }
062:
063: public WriteIfDifferentOutputStream(File file) throws IOException {
064: this (new RandomAccessFile(file, "rw")); // NOI18N
065: }
066:
067: public void write(int b) throws IOException {
068: if (justWrite) {
069: randFile.write(b);
070: return;
071: }
072: long fp = randFile.getFilePointer();
073: if (fp + 1 > initialRandFileLength) {
074: justWrite = true;
075: randFile.write(b);
076: return;
077: }
078: int fromFile = randFile.read();
079: if (fromFile != b) {
080: //System.out.println("different: fromFile="+fromFile+" b="+b);
081: randFile.seek(fp);
082: randFile.write(b);
083: justWrite = true;
084: return;
085: }
086: }
087:
088: private byte[] writeBuf;
089: private int lastLen = -1;
090:
091: public void write(byte[] b, int off, int len) throws IOException {
092: if (justWrite) {
093: randFile.write(b, off, len);
094: return;
095: }
096: long fp = randFile.getFilePointer();
097: if (fp + len > initialRandFileLength) {
098: justWrite = true;
099: randFile.write(b, off, len);
100: return;
101: }
102: if (len > lastLen) {
103: // Allocate a new buffer only if the last one wasn't big enough.
104: writeBuf = new byte[len];
105: lastLen = len;
106: }
107: randFile.read(writeBuf, 0, len);
108: for (int i = off, j = 0; j < len; ++i, ++j) {
109: if (writeBuf[j] != b[i]) {
110: //System.out.println("different: i="+i+" j="+j);
111: randFile.seek(fp);
112: randFile.write(b, off, len);
113: justWrite = true;
114: return;
115: }
116: }
117: }
118:
119: /*
120: public void flush() throws IOException {
121: randFile.flush();
122: }
123: */
124:
125: /**
126: * At this point, have we changed the file?
127: * It's possible to not change a file until close() is called.
128: */
129: public boolean isChanged() {
130: return justWrite;
131: }
132:
133: public void close() throws IOException {
134: // Truncate it.
135: //System.out.println("truncating to "+randFile.getFilePointer());
136: if (randFile.getFilePointer() < randFile.length()) {
137: justWrite = true;
138: randFile.setLength(randFile.getFilePointer());
139: }
140: randFile.close();
141: }
142: }
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