/**
* Licensed to Cloudera, Inc. under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Cloudera, Inc. 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 com.cloudera.flume.reporter.sampler;
import java.io.IOException;
import com.cloudera.flume.conf.Context;
import com.cloudera.flume.conf.SinkFactory.SinkDecoBuilder;
import com.cloudera.flume.core.Event;
import com.cloudera.flume.core.EventSink;
import com.cloudera.flume.core.EventSinkDecorator;
/**
* This simple sampler deterministically takes every nth event.
*
* This sampler is not thread safe;
*
* TODO(jon) make samplers just use EventSink instead of ReportingSink. Use
* ReportManager to manage all ReportingSinks.
*/
public class IntervalSampler<S extends EventSink> extends EventSinkDecorator<S> {
int interval;
int count = 0;
public IntervalSampler(S s, int inteval) {
super(s);
this.interval = inteval;
}
@Override
public void append(Event e) throws IOException {
if (count % interval == 0) {
// forward
getSink().append(e);
count = 1;
return;
}
count++;
// drop message
}
public static SinkDecoBuilder builder() {
return new SinkDecoBuilder() {
@Override
public EventSinkDecorator<EventSink> build(Context context,
String... argv) {
if (argv.length != 1) {
throw new IllegalArgumentException(
"usage: intervalSampler(intervalsize)");
}
int interval = Integer.parseInt(argv[0]);
return new IntervalSampler<EventSink>(null, interval);
}
};
}
}