| /** |
| * 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; |
| |
| import java.util.HashSet; |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.Set; |
| |
| import org.apache.heron.api.spout.IRichSpout; |
| import org.apache.heron.api.topology.TopologyBuilder; |
| import org.apache.heron.streamlet.Builder; |
| import org.apache.heron.streamlet.SerializableSupplier; |
| import org.apache.heron.streamlet.Source; |
| import org.apache.heron.streamlet.Streamlet; |
| import org.apache.heron.streamlet.impl.streamlets.SourceStreamlet; |
| import org.apache.heron.streamlet.impl.streamlets.SpoutStreamlet; |
| import org.apache.heron.streamlet.impl.streamlets.SupplierStreamlet; |
| |
| import static org.apache.heron.streamlet.impl.utils.StreamletUtils.checkNotNull; |
| |
| /** |
| * BuilderImpl implements the Builder interface. |
| * The builder keeps track of the all the sources of the |
| * computation DAG and builds the Topology by traversing all |
| * the computation nodes. |
| */ |
| public final class BuilderImpl implements Builder { |
| private List<StreamletImpl<?>> sources; |
| public BuilderImpl() { |
| sources = new LinkedList<>(); |
| } |
| |
| @Override |
| public <R> Streamlet<R> newSource(SerializableSupplier<R> supplier) { |
| checkNotNull(supplier, "supplier cannot not be null"); |
| |
| StreamletImpl<R> retval = new SupplierStreamlet<>(supplier); |
| sources.add(retval); |
| return retval; |
| } |
| |
| @Override |
| public <R> Streamlet<R> newSource(Source<R> generator) { |
| checkNotNull(generator, "generator cannot not be null"); |
| |
| StreamletImpl<R> retval = new SourceStreamlet<>(generator); |
| sources.add(retval); |
| return retval; |
| } |
| |
| @Override |
| public <R> Streamlet<R> newSource(IRichSpout spout) { |
| checkNotNull(spout, "spout cannot not be null"); |
| |
| StreamletImpl<R> retval = new SpoutStreamlet<>(spout); |
| sources.add(retval); |
| return retval; |
| } |
| |
| /** |
| * We start traversing from all sources and build each node. |
| * @return TopologyBuilder class that represents the built topology |
| */ |
| public TopologyBuilder build() { |
| TopologyBuilder builder = new TopologyBuilder(); |
| return build(builder); |
| } |
| |
| public TopologyBuilder build(TopologyBuilder builder) { |
| checkNotNull(builder, "builder cannot not be null"); |
| |
| Set<String> stageNames = new HashSet<>(); |
| for (StreamletImpl<?> streamlet : sources) { |
| streamlet.build(builder, stageNames); |
| } |
| for (StreamletImpl<?> streamlet : sources) { |
| if (!streamlet.allBuilt()) { |
| throw new RuntimeException("Topology cannot be fully built! Are all sources added?"); |
| } |
| } |
| return builder; |
| } |
| } |