/*
* Copyright (c) 2001-2007 Sun Microsystems, Inc. All rights reserved.
*
* The Sun Project JXTA(TM) Software License
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. The end-user documentation included with the redistribution, if any, must
* include the following acknowledgment: "This product includes software
* developed by Sun Microsystems, Inc. for JXTA(TM) technology."
* Alternately, this acknowledgment may appear in the software itself, if
* and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must
* not be used to endorse or promote products derived from this software
* without prior written permission. For written permission, please contact
* Project JXTA at http://www.jxta.org.
*
* 5. Products derived from this software may not be called "JXTA", nor may
* "JXTA" appear in their name, without prior written permission of Sun.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SUN
* MICROSYSTEMS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* JXTA is a registered trademark of Sun Microsystems, Inc. in the United
* States and other countries.
*
* Please see the license information page at :
* <http://www.jxta.org/project/www/license.html> for instructions on use of
* the license in source files.
*
* ====================================================================
*
* This software consists of voluntary contributions made by many individuals
* on behalf of Project JXTA. For more information on Project JXTA, please see
* http://www.jxta.org.
*
* This license is based on the BSD license adopted by the Apache Foundation.
*/
package net.jxta.test.util;
import java.io.ByteArrayOutputStream;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Collection;
class WatchedOutputStream extends FilterOutputStream
implements WatchedStream {
static final int DEFAULT_CHUNK_SIZE = 4096;
transient Collection watchList = null;
transient volatile boolean stalled = false;
transient volatile boolean idle = true;
transient boolean closed = false;
transient final int chunkSize;
transient OutputStream out = null;
public WatchedOutputStream(OutputStream out, int chunkSize) {
super(out);
this.out = out;
this.chunkSize = chunkSize;
}
public WatchedOutputStream(OutputStream out) {
this(out, DEFAULT_CHUNK_SIZE);
}
/**
* {@inheritDoc}
* <p/>
* <p/>Debugging toString.
*/
@Override
public String toString() {
if (null == out) {
return "closed/" + super.toString();
} else {
if (out instanceof ByteArrayOutputStream) {
// ByteArrayInputStream.toString() prints the entire stream!
return out.getClass().getName() + "@" + System.identityHashCode(out) + "/" + super.toString();
} else {
return out.toString() + "/" + super.toString();
}
}
}
/**
* Sets the watcher list onto which this stream must register
* when it is not idle (so that it can be watched).
* This implementation may or may not remain registered while idle.
* This may affect performance but not functionality.
* It is assumed that that list is monitored by a watcher task that
* invokes the watch method as often as needed to monitor progress
* to its satisfaction.
*
* @param watchList The watchList to register with. Must be a
* Synchronized Collection.
*/
public synchronized void setWatchList(Collection watchList) {
if (this.watchList != null) {
this.watchList.remove(this);
}
this.watchList = watchList;
watchList.add(this);
}
// This routine may be invoked as often as progress needs to be asserted.
// After at most two watch cycles stalling is detected.
public void watch() {
if (idle) {
return;
}
if (!stalled) {
stalled = true; // challenge a write method to clear that flag.
return;
}
// It's stalled. The last time around it was not idle, so we set the
// stalled flag. Now, it is still not idle and the flag is still there.
// break the stream.
try {
close();
} catch (IOException ioe) {
;
}
}
@Override
public void close() throws IOException {
idle = true;
synchronized (this) {
if (watchList != null) {
watchList.remove(this);
watchList = null;
}
// Avoid calling close redundantly; some OSes seem to have
// deadlock capabilities when doing that.
if (closed) {
return;
}
closed = true;
}
super.close();
}
@Override
public void flush() throws IOException {
stalled = false;
idle = false;
try {
out.flush();
} finally {
idle = true;
}
}
@Override
public void write(int b) throws IOException {
stalled = false;
idle = false;
try {
out.write(b);
} finally {
idle = true;
}
}
// We overload it; not trusting that the base classe's method does
// call write(byte[], int, int) in the future.
@Override
public void write(byte[] b) throws IOException {
write(b, 0, b.length);
}
// We overload it; not wanting the base classe's method to
// call write(int).
@Override
public void write(byte[] b, int off, int len) throws IOException {
// Do the standard checks here. Since we will be calling write
// repeatedly, errors could be discovered too late per write's
// contract.
if ((off < 0) || (len < 0) || ((off + len) > b.length) || ((off + len) < 0)) {
throw new IndexOutOfBoundsException();
} else if (len == 0) {
return;
}
stalled = false;
idle = false;
try {
while (len > chunkSize) {
out.write(b, off, chunkSize);
stalled = false;
off += chunkSize;
len -= chunkSize;
}
if (len > 0) {
out.write(b, off, len);
}
} finally {
idle = true;
}
}
}