org.apache.manifoldcf.amazons3.XThreadBuffer Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.manifoldcf.amazons3;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.apache.manifoldcf.crawler.system.Logging;
/**
* Generic XThread class
* @author Kuhajeyan
*
* @param
*/
public class XThreadBuffer {
protected static int MAX_SIZE = 1024;
protected List buffer = Collections.synchronizedList(new ArrayList(
MAX_SIZE));
protected boolean complete = false;
protected boolean abandoned = false;
/** Constructor */
public XThreadBuffer() {
}
public synchronized void add(T t) throws InterruptedException {
while (buffer.size() == MAX_SIZE && !abandoned)
wait();
if (abandoned)
return;
buffer.add(t);
// Notify threads that are waiting on there being stuff in the queue
notifyAll();
}
public synchronized void abandon() {
abandoned = true;
// Notify waiting threads
notifyAll();
}
public synchronized T fetch() throws InterruptedException {
while (buffer.size() == 0 && !complete)
{
if (Logging.connectors != null) {
Logging.connectors.info("thread will be put to wait");
}
wait();
}
if (buffer.size() == 0)
return null;
boolean isBufferFull = (buffer.size() == MAX_SIZE);
T rval = buffer.remove(buffer.size() - 1);
// Notify those threads waiting on buffer being not completely full to
// wake
if (isBufferFull)
notifyAll();
return rval;
}
public synchronized void signalDone() {
complete = true;
// Notify threads that are waiting for stuff to appear, because it won't
notifyAll();
}
}