com.twitter.heron.streamlet.impl.streamlets.SupplierStreamlet Maven / Gradle / Ivy
// Copyright 2017 Twitter. 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.
package com.twitter.heron.streamlet.impl.streamlets;
import java.util.Set;
import com.twitter.heron.api.topology.TopologyBuilder;
import com.twitter.heron.streamlet.SerializableSupplier;
import com.twitter.heron.streamlet.impl.StreamletImpl;
import com.twitter.heron.streamlet.impl.sources.SupplierSource;
/**
* SupplierStreamlet is a very quick and flexible way of creating a Streamlet
* from an user supplied Supplier Function. The supplier function is the
* source of all tuples for this Streamlet.
*/
public class SupplierStreamlet extends StreamletImpl {
private SerializableSupplier supplier;
public SupplierStreamlet(SerializableSupplier supplier) {
this.supplier = supplier;
setNumPartitions(1);
}
@Override
public boolean doBuild(TopologyBuilder bldr, Set stageNames) {
setDefaultNameIfNone(StreamletNamePrefix.SUPPLIER, stageNames);
bldr.setSpout(getName(), new SupplierSource(supplier), getNumPartitions());
return true;
}
}