org.apache.hadoop.hive.ql.exec.NodeUtils Maven / Gradle / Ivy
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* 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.exec;
import org.apache.hadoop.hive.ql.lib.Node;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/**
* Simple node iterating utils
*/
public class NodeUtils {
public static void iterateTask(Collection> tasks, Class clazz, Function function) {
// Does a breadth first traversal of the tasks
Set visited = new HashSet();
while (!tasks.isEmpty()) {
tasks = iterateTask(tasks, clazz, function, visited);
}
return;
}
private static Collection> iterateTask(Collection> tasks,
Class clazz,
Function function,
Set visited) {
Collection> childTasks = new ArrayList<>();
for (Task task : tasks) {
if (!visited.add(task)) {
continue;
}
if (clazz.isInstance(task)) {
function.apply(clazz.cast(task));
}
// this is for ConditionalTask
if (task.getDependentTasks() != null) {
childTasks.addAll(task.getDependentTasks());
}
}
return childTasks;
}
public static void iterate(Collection nodes, Class clazz, Function function) {
Set visited = new HashSet();
List> listNodes = Collections.singletonList(nodes);
while (!listNodes.isEmpty()) {
listNodes = iterate(listNodes, clazz, function, visited);
}
return;
}
private static List> iterate(List> listNodes,
Class clazz,
Function function,
Set visited) {
List> childListNodes = new ArrayList<>();
for (Collection nodes : listNodes) {
for (Node node : nodes) {
if (!visited.add(node)) {
continue;
}
if (clazz.isInstance(node)) {
function.apply(clazz.cast(node));
}
if (node.getChildren() != null) {
childListNodes.add(node.getChildren());
}
}
}
return childListNodes;
}
public interface Function {
void apply(T argument);
}
}