package com.linkedin.databus.core.test;
/*
*
* Copyright 2013 LinkedIn Corp. All rights reserved
*
* 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.
*
*/
import java.util.HashSet;
import java.util.Vector;
import org.apache.log4j.Logger;
import com.linkedin.databus.core.DbusEvent;
import com.linkedin.databus.core.DbusEventBuffer;
import com.linkedin.databus.core.DbusEventBuffer.DbusEventIterator;
import com.linkedin.databus.core.util.EventBufferConsumer;
import com.linkedin.databus.core.DbusEventInternalReadable;
/**
* Consumes Dbus events from the buffer using a DbusEventInterator and drops them into the vector.
*
* This class is intended only for testing!
*/
public class DbusEventBufferConsumer implements Runnable , EventBufferConsumer
{
public static final Logger LOG = Logger.getLogger(DbusEventBufferConsumer.class.getName());
public DbusEventBufferConsumer(DbusEventBuffer buffer,
int maxEvents,
int deletionInterval,
Vector<DbusEvent> out)
{
_buffer = buffer;
_out = out;
_seenKeys = new HashSet<Long>();
_maxEvents = maxEvents;
_stop = false;
_deletionInterval = deletionInterval;
_invalidEvent = false;
_eventsReadTillInvalidEvent = 0;
}
@Override
public void run()
{
reset();
try
{
int totalEvents = 0;
long allTotalEvents = 0;
DbusEventIterator iDbusEvent = _buffer.acquireIterator("Test_DbusEventBufferConsumer");
do {
if (!iDbusEvent.hasNext()) {
if (!_invalidEvent) {
if (_deletionInterval>0) {
iDbusEvent.remove();
}
try
{
iDbusEvent.await();
}
catch (InterruptedException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
return;
}
} else {
//try and consume as many events as possible
if (allTotalEvents >= eventsReadTillInvalidEvent()) {
LOG.info("total events read until invalid event=" + allTotalEvents + "; terminating");
stop();
}
}
}
while (iDbusEvent.hasNext()) {
DbusEventInternalReadable e = iDbusEvent.next();
++allTotalEvents;
if (!e.isCheckpointMessage() && !e.isControlMessage() && !e.isEndOfPeriodMarker()) {
//needs to be idempotent; so - ensure that duplicates are dropped;
if (!_seenKeys.contains(e.key())) {
//deep copy
_out.add(e.createCopy());
_seenKeys.add(e.key());
++totalEvents;
}
}
if ((_deletionInterval>0) && allTotalEvents % _deletionInterval==0) {
iDbusEvent.remove();
}
}
}
while (totalEvents < _maxEvents && !_stop);
iDbusEvent.remove();
}
catch (RuntimeException e)
{
_exceptionThrown = e;
LOG.error("consumer exception:" + e.getMessage(), e);
}
catch (Error e)
{
_exceptionThrown = e;
LOG.error("consumer error:" + e.getMessage(), e);
}
}
/** Run the consumer with timeout */
public boolean runWithTimeout(long timeoutMs)
{
Thread runThread = new Thread(this, "runWithTimeout-" + this);
runThread.setDaemon(true);
runThread.start();
try {
runThread.join(timeoutMs);
}
catch (InterruptedException e){}
final boolean success = !runThread.isAlive();
if (!success)
{
stop();
runThread.interrupt();
}
return success;
}
@Override
public void onInvalidEvent(long numEventsRead)
{
_invalidEvent = true;
_eventsReadTillInvalidEvent = numEventsRead;
}
public void stop()
{
_stop = true;
}
public boolean hasStopped()
{
return _stop;
}
public boolean hasInvalidEvent()
{
return _invalidEvent;
}
public long eventsReadTillInvalidEvent()
{
return _eventsReadTillInvalidEvent;
}
public void reset()
{
_stop = false;
_invalidEvent = false;
_eventsReadTillInvalidEvent = 0;
_exceptionThrown = null;
}
private final DbusEventBuffer _buffer;
private final Vector<DbusEvent> _out;
private final HashSet<Long> _seenKeys;
private final int _maxEvents;
private boolean _stop;
private final int _deletionInterval;
private boolean _invalidEvent;
private long _eventsReadTillInvalidEvent;
private volatile Throwable _exceptionThrown;
public Throwable getExceptionThrown()
{
return _exceptionThrown;
}
}