/**
* 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.hadoop.hive.ql.optimizer.physical;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Queue;
import java.util.Set;
import java.util.concurrent.ConcurrentLinkedQueue;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.ql.exec.ConditionalTask;
import org.apache.hadoop.hive.ql.exec.Task;
import org.apache.hadoop.hive.ql.parse.SemanticException;
/**
* Simple renumbering of stage ids
*/
public class StageIDsRearranger implements PhysicalPlanResolver {
private static final String PREFIX = "Stage-";
enum ArrangeType {
NONE, IDONLY, TRAVERSE, EXECUTION
}
@Override
public PhysicalContext resolve(PhysicalContext pctx) throws SemanticException {
int counter = 0;
for (Task task : getExplainOrder(pctx)) {
task.setId(PREFIX + (++counter));
}
return null;
}
private static List<Task> getExplainOrder(PhysicalContext pctx) {
List<Task> tasks = getExplainOrder(pctx.getConf(), pctx.getRootTasks());
if (pctx.getFetchTask() != null) {
tasks.add(pctx.getFetchTask());
}
return tasks;
}
public static List<Task> getFetchSources(List<Task<?>> tasks) {
final List<Task> sources = new ArrayList<Task>();
TaskTraverse traverse = new TaskTraverse() {
@Override
protected void accepted(Task<?> task) {
if (task.getNumChild() == 0 && task.isFetchSource()) {
sources.add(task);
}
}
};
for (Task<? extends Serializable> task : tasks) {
traverse.traverse(task);
}
return sources;
}
public static List<Task> getExplainOrder(HiveConf conf, List<Task<?>> tasks) {
for (Task<? extends Serializable> task : tasks) {
task.setRootTask(true);
}
String var = conf.getVar(HiveConf.ConfVars.HIVESTAGEIDREARRANGE);
ArrangeType type = ArrangeType.valueOf(var.toUpperCase());
if (type == ArrangeType.EXECUTION) {
return executionOrder(tasks);
}
return traverseOrder(type, tasks);
}
private static List<Task> executionOrder(List<Task<?>> tasks) {
final Queue<Task<?>> queue = new ConcurrentLinkedQueue<Task<?>>(tasks);
TaskTraverse traverse = new TaskTraverse() {
@Override
protected void accepted(Task<?> task) {
List<Task<?>> childTasks = getChildTasks(task);
if (childTasks != null && !childTasks.isEmpty()) {
queue.addAll(childTasks);
}
}
@Override
protected void rejected(Task<?> child) {
queue.add(child);
}
@Override
protected List<Task<?>> next(Task<?> task) {
return queue.isEmpty() ? null : Arrays.<Task<?>>asList(queue.remove());
}
};
if (!queue.isEmpty()) {
traverse.traverse(queue.remove());
}
return new ArrayList<Task>(traverse.traversed);
}
static List<Task> traverseOrder(final ArrangeType type, List<Task<?>> tasks) {
TaskTraverse traverse = new TaskTraverse() {
@Override
protected boolean isReady(Task<?> task) {
return type == ArrangeType.NONE || type == ArrangeType.IDONLY || super.isReady(task);
}
};
for (Task<? extends Serializable> task : tasks) {
traverse.traverse(task);
}
return new ArrayList<Task>(traverse.traversed);
}
public static abstract class TaskTraverse {
protected final Set<Task<?>> traversed = new LinkedHashSet<Task<?>>();
public void traverse(Task<?> task) {
if (traversed.add(task)) {
accepted(task);
}
List<Task<?>> children = next(task);
if (children != null && !children.isEmpty()) {
for (Task<?> child : children) {
if (isReady(child)) {
traverse(child);
} else {
rejected(child);
}
}
}
}
protected boolean isReady(Task<?> task) {
return task.getParentTasks() == null || traversed.containsAll(task.getParentTasks());
}
protected void accepted(Task<?> task) {
}
protected void rejected(Task<?> child) {
}
protected List<Task<?>> next(Task<?> task) {
return getChildTasks(task);
}
protected List<Task<?>> getChildTasks(Task<?> task) {
if (task instanceof ConditionalTask) {
return ((ConditionalTask) task).getListTasks();
}
return task.getChildTasks();
}
}
}