/*

 * Copyright (c) 2012, 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.tools.sjavac.comp;

import java.io.*;

import javax.tools.JavaFileObject;

/**

 * The SmartWriter will cache the written data and when the writer is closed,

 * then it will compare the cached data with the old_content string.

 * If different, then it will write all the new content to the file.

 * If not, the file is not touched.

 *

 *  <p><b>This is NOT part of any supported API.

 *  If you write code that depends on this, you do so at your own risk.

 *  This code and its internal interfaces are subject to change or

 *  deletion without notice.</b>

 */

public class SmartWriter extends Writer {

    String name;

    JavaFileObject file;

    String oldContent;

    StringWriter newContent = new StringWriter();

    PrintWriter stdout;

    boolean closed;

    public SmartWriter(JavaFileObject f, String s, String n, PrintWriter pw) {

        name = n;

        file = f;

        oldContent = s;

        newContent = new StringWriter();

        stdout = pw;

        closed = false;

    }

    public void write(char[] chars, int i, int i1)

    {

        newContent.write(chars, i, i1);

    }

    public void close() throws IOException {

        if (closed) return;

        closed = true;

        String s = newContent.toString();

        if (!oldContent.equals(s)) {

            int p = file.getName().lastIndexOf(File.separatorChar);

            try (Writer writer = file.openWriter()) {

                writer.write(s);

            }

            stdout.println("Writing "+file.getName().substring(p+1));

        }

    }

    public void flush() throws IOException {

    }

}