/*
* Copyright 2016
* Ubiquitous Knowledge Processing (UKP) Lab
* Technische Universität Darmstadt
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package de.tudarmstadt.ukp.dkpro.core.opennlp.internal;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.uima.jcas.JCas;
import opennlp.tools.util.ObjectStream;
public abstract class CasSampleStreamBase<T>
implements ObjectStream<T>
{
private boolean complete = false;
private boolean inProduction = false;
private AtomicReference<JCas> jcasReference = new AtomicReference<>();
private Thread readingThread;
private Thread sendingThread;
public CasSampleStreamBase()
{
// Nothing to do
}
public void send(JCas aJCas) {
jcasReference.set(aJCas);
if (readingThread != null) {
readingThread.interrupt();
}
// Wait for the CAS to have been processed
while (inProduction || (!complete && jcasReference.get() != null)) {
try {
sendingThread = Thread.currentThread();
TimeUnit.MILLISECONDS.sleep(10);
}
catch (InterruptedException e) {
sendingThread = null;
Thread.interrupted();
// Ignore
}
}
}
@Override
public T read()
throws IOException
{
if (complete) {
// Nothing more to read
return null;
}
// Block while the processing is not complete and we do not have a CAS
while (jcasReference.get() == null || !isActive()) {
if (complete) {
// Nothing more to read
return null;
}
// Get sentences if any available
if (jcasReference.get() != null) {
init(jcasReference.get());
}
else {
try {
readingThread = Thread.currentThread();
TimeUnit.MILLISECONDS.sleep(10);
}
catch (InterruptedException e) {
Thread.interrupted();
readingThread = null;
// Ignore
}
}
}
try {
inProduction = true;
return produce(jcasReference.get());
}
finally {
inProduction = false;
}
}
public abstract void init(JCas aJCas);
public abstract boolean isActive();
public abstract T produce(JCas aJCas);
public void documentComplete()
{
jcasReference.set(null);
}
@Override
public void reset()
throws IOException, UnsupportedOperationException
{
throw new UnsupportedOperationException();
}
@Override
public void close()
throws IOException
{
complete = true;
}
}