/*
* Geotoolkit.org - An Open Source Java GIS Toolkit
* http://www.geotoolkit.org
*
* (C) 2010-2012, Geomatys
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library 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
* Lesser General Public License for more details.
*/
package org.geotoolkit.internal.image.io;
import org.apache.sis.util.logging.Logging;
import org.geotoolkit.lang.Debug;
import org.geotoolkit.lang.Decorator;
import javax.imageio.stream.ImageOutputStream;
import java.io.IOException;
import java.util.Arrays;
/**
* An image output stream which checks if the stream has been closed. The check is performed
* at garbage-collection time. This class is used only for debugging purpose, as a way to
* trace the place where the output stream may not have been properly closed.
*
* @author Quentin Boileau (Geomatys)
*/
@Debug
@Decorator(ImageOutputStream.class)
public final class CheckedImageOutputStream extends ImageOutputStreamProxy {
/**
* {@code true} if {@link #close()} has been invoked.
*/
private volatile boolean isClosed;
/**
* The creator of this output stream, used in order to format a log message if needed.
*/
private final StackTraceElement[] creator;
/**
* Creates a new instance wrapping the given stream.
*
* @param out The image output stream to wrap.
*/
private CheckedImageOutputStream(final ImageOutputStream out) {
super(out);
StackTraceElement[] creator = Thread.currentThread().getStackTrace();
for (int i=0; i<creator.length; i++) {
final String c = creator[i].getClassName();
if (!c.equals("java.lang.Thread") && !c.equals("org.geotoolkit.internal.image.io.CheckedImageOutputStream")) {
creator = Arrays.copyOfRange(creator, i, creator.length);
break;
}
}
this.creator = creator;
}
/**
* Creates a new instance wrapping the given stream, or returns {@code null}
* if the given instance was null.
*
* @param out The image output stream to wrap, or {@code null}.
* @return The wrapped image output stream, or {@code null}.
*/
public static ImageOutputStream wrap(ImageOutputStream out) {
if (out != null && !(out instanceof CheckedImageOutputStream)) {
out = new CheckedImageOutputStream(out);
}
return out;
}
/**
* Returns {@code true} if the given output stream is null, or is a valid
* {@link CheckedImageOutputStream}. This method is used only for assertions purpose.
*
* @param out The output stream to check.
* @return {@code true} if the given output stream is valid.
*/
public static boolean isValid(final ImageOutputStream out) {
return (out == null) || (out instanceof CheckedImageOutputStream &&
!((CheckedImageOutputStream) out).isClosed);
}
/**
* Closes the stream.
*/
@Override
public void close() throws IOException {
isClosed = true;
super.close();
}
/**
* Checks if the output stream has been closed.
*/
@Override
protected void finalize() {
if (!isClosed) {
final StringBuilder buffer = new StringBuilder("ImageOutputStream created below has not been closed:\n");
for (final StackTraceElement element : creator) {
buffer.append(" ").append(element).append('\n');
}
Logging.getLogger("org.geotoolkit.image.io").warning(buffer.toString());
}
}
}