/*
* 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.flume.source;
import org.apache.flume.Context;
import org.apache.flume.EventDeliveryException;
import org.apache.flume.FlumeException;
import org.apache.flume.PollableSource;
import org.apache.flume.annotations.InterfaceAudience;
import org.apache.flume.annotations.InterfaceStability;
/**
* Base class which ensures sub-classes will inherit all the properties
* of BasicSourceSemantics in addition to:
* <ol>
* <li>Ensuring when configure/start throw an exception process will not
* be called</li>
* <li>Ensure that process will not be called unless configure and start
* have successfully been called</li>
* </ol>
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving
public abstract class AbstractPollableSource
extends BasicSourceSemantics implements PollableSource {
long backoffSleepIncrement = PollableSourceConstants.DEFAULT_BACKOFF_SLEEP_INCREMENT;
long maxBackoffSleep = PollableSourceConstants.DEFAULT_MAX_BACKOFF_SLEEP;
public AbstractPollableSource() {
super();
}
public Status process() throws EventDeliveryException {
Exception exception = getStartException();
if (exception != null) {
throw new FlumeException("Source had error configuring or starting",
exception);
}
if (!isStarted()) {
throw new EventDeliveryException("Source is not started. It is in '" +
getLifecycleState() + "' state");
}
return doProcess();
}
@Override
public synchronized void configure(Context context) {
super.configure(context);
backoffSleepIncrement =
context.getLong(PollableSourceConstants.BACKOFF_SLEEP_INCREMENT,
PollableSourceConstants.DEFAULT_BACKOFF_SLEEP_INCREMENT);
maxBackoffSleep = context.getLong(PollableSourceConstants.MAX_BACKOFF_SLEEP,
PollableSourceConstants.DEFAULT_MAX_BACKOFF_SLEEP);
}
public long getBackOffSleepIncrement() {
return backoffSleepIncrement;
}
public long getMaxBackOffSleepInterval() {
return maxBackoffSleep;
}
protected abstract Status doProcess() throws EventDeliveryException;
}