--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tracefw/tracecompiler/src/com.nokia.tracecompiler/src/com/nokia/tracecompiler/file/FileCompareOutputStream.java	Tue Aug 31 16:45:49 2010 +0300
@@ -0,0 +1,82 @@
+/*
+* Copyright (c) 2007 Nokia Corporation and/or its subsidiary(-ies). 
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:
+*
+* Output stream which compares the data to existing file before writing
+*
+*/
+package com.nokia.tracecompiler.file;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * Output stream which writes to a byte array. When writing is complete, the
+ * array contents are compared to existing file and the file is written only if
+ * there are changes
+ * 
+ */
+public class FileCompareOutputStream extends ByteArrayOutputStream {
+
+	/**
+	 * The header file
+	 */
+	private File file;
+
+	/**
+	 * Creates a new stream
+	 * 
+	 * @param file
+	 *            the header file
+	 */
+	public FileCompareOutputStream(File file) {
+		this.file = file;
+	}
+
+	/**
+	 * Writes the buffer to file if it has changed
+	 * 
+	 * @return true if header was written, false if it matched the existing
+	 *         header
+	 * @throws IOException
+	 *             if writing fails
+	 */
+	public boolean writeFile() throws IOException {
+		// Compares the file length to number of bytes in array
+		boolean writeHeader = true;
+		if (file.length() == count) {
+			FileInputStream fis = new FileInputStream(file);
+			byte[] temp = new byte[count];
+			fis.read(temp);
+			fis.close();
+			writeHeader = false;
+			// Compares the file content
+			for (int i = 0; i < count; i++) {
+				if (temp[i] != buf[i]) {
+					writeHeader = true;
+					i = count;
+				}
+			}
+		}
+		if (writeHeader) {
+			OutputStream fos = FileUtils.createOutputStream(file);
+			writeTo(fos);
+			fos.close();
+		}
+		return writeHeader;
+	}
+}
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