| /** |
| * 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.heron.streamlet.impl.sources; |
| |
| import org.apache.heron.api.tuple.Values; |
| import org.apache.heron.streamlet.SerializableSupplier; |
| |
| /** |
| * SupplierSource is a way to wrap a supplier function inside a Heron Spout. |
| * The SupplierSource just calls the get method of the supplied function |
| * to generate the next tuple. |
| */ |
| public class SupplierSource<R> extends StreamletSource { |
| |
| private static final long serialVersionUID = 6476611751545430216L; |
| private SerializableSupplier<R> supplier; |
| |
| public SupplierSource(SerializableSupplier<R> supplier) { |
| this.supplier = supplier; |
| } |
| |
| @Override |
| public void nextTuple() { |
| collector.emit(new Values(supplier.get())); |
| } |
| } |