| /* |
| * 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.wayang.core.plan.executionplan; |
| |
| import java.util.Collection; |
| import java.util.HashSet; |
| import org.apache.wayang.core.plan.wayangplan.ExecutionOperator; |
| import org.apache.wayang.core.plan.wayangplan.LoopHeadOperator; |
| import org.apache.wayang.core.plan.wayangplan.LoopSubplan; |
| |
| /** |
| * This class models the execution equivalent of {@link LoopSubplan}s. |
| */ |
| public class ExecutionStageLoop { |
| |
| private final LoopSubplan loopSubplan; |
| |
| private ExecutionStage headStageCache; |
| |
| private final Collection<ExecutionStage> allStages = new HashSet<>(); |
| |
| public ExecutionStageLoop(LoopSubplan loopSubplan) { |
| this.loopSubplan = loopSubplan; |
| } |
| |
| public void add(ExecutionStage executionStage) { |
| if (this.allStages.add(executionStage)) { |
| if (this.headStageCache == null && this.checkForLoopHead(executionStage)) { |
| this.headStageCache = executionStage; |
| } |
| } |
| } |
| |
| private boolean checkForLoopHead(ExecutionStage executionStage) { |
| return executionStage.getAllTasks().stream().anyMatch(this::isLoopHead); |
| } |
| |
| /** |
| * Checks whether the given {@link ExecutionTask} is the {@link LoopHeadOperator} of the {@link #loopSubplan}. |
| * |
| * @param task to be checked |
| * @return whether it is the {@link LoopHeadOperator} |
| */ |
| private boolean isLoopHead(ExecutionTask task) { |
| final ExecutionOperator operator = task.getOperator(); |
| return operator.isLoopHead() && operator.getInnermostLoop() == this.loopSubplan; |
| } |
| |
| /** |
| * Inspect whether {@link ExecutionTask} is the {@link LoopHeadOperator} of the {@link #loopSubplan}. If so, |
| * promote its {@link ExecutionStage} as the loop head. |
| * |
| * @param task to be checked |
| */ |
| public void update(ExecutionTask task) { |
| if (this.headStageCache == null && this.isLoopHead(task)) { |
| this.headStageCache = task.getStage(); |
| } |
| } |
| |
| /** |
| * Retrieves the {@link ExecutionStage} that contains the {@link LoopHeadOperator} of this instance. |
| * |
| * @return the loop head {@link ExecutionStage} |
| */ |
| public ExecutionStage getLoopHead() { |
| if (this.headStageCache == null) { |
| this.allStages.stream() |
| .flatMap(executionStage -> executionStage.getAllTasks().stream()) |
| .forEach(this::update); |
| } |
| assert this.headStageCache != null : String.format("No ExecutionStageLoop head for %s.", this.loopSubplan); |
| |
| return this.headStageCache; |
| } |
| |
| /** |
| * Retrieve the {@link LoopSubplan} encapsulated by this instance. |
| * |
| * @return the {@link LoopSubplan} |
| */ |
| public LoopSubplan getLoopSubplan() { |
| return loopSubplan; |
| } |
| } |