/*
* 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.beam.runners.spark.translation.streaming;
import java.util.ArrayList;
import java.util.List;
import org.apache.beam.runners.spark.translation.Dataset;
import org.apache.beam.runners.spark.translation.TranslationUtils;
import org.apache.beam.sdk.util.WindowedValue;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.function.VoidFunction;
import org.apache.spark.streaming.api.java.JavaDStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* DStream holder Can also crate a DStream from a supplied queue of values, but mainly for testing.
*/
public class UnboundedDataset<T> implements Dataset {
private static final Logger LOG = LoggerFactory.getLogger(UnboundedDataset.class);
private final JavaDStream<WindowedValue<T>> dStream;
// points to the input streams that created this UnboundedDataset,
// should be greater > 1 in case of Flatten for example.
// when using GlobalWatermarkHolder this information helps to take only the relevant watermarks
// and reason about them accordingly.
private final List<Integer> streamSources = new ArrayList<>();
public UnboundedDataset(JavaDStream<WindowedValue<T>> dStream, List<Integer> streamSources) {
this.dStream = dStream;
this.streamSources.addAll(streamSources);
}
JavaDStream<WindowedValue<T>> getDStream() {
return dStream;
}
List<Integer> getStreamSources() {
return streamSources;
}
public void cache() {
dStream.cache();
}
@Override
public void cache(String storageLevel) {
// we "force" MEMORY storage level in streaming
LOG.warn("Provided StorageLevel ignored for stream, using default level");
cache();
}
@Override
public void action() {
// Force computation of DStream.
dStream.foreachRDD(new VoidFunction<JavaRDD<WindowedValue<T>>>() {
@Override
public void call(JavaRDD<WindowedValue<T>> rdd) throws Exception {
rdd.foreach(TranslationUtils.<WindowedValue<T>>emptyVoidFunction());
}
});
}
@Override
public void setName(String name) {
// ignore
}
}