org.apache.hadoop.hive.ql.optimizer.NestedColumnFieldPruningUtils Maven / Gradle / Ivy
/**
* 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;
import java.util.Arrays;
import java.util.List;
public class NestedColumnFieldPruningUtils {
/**
* Add a leaf node to the field tree if the specified path is not contained by
* current tree specified by the passed parameter field node.
*
* @param fieldNode the root of the column tree
* @param path contains the path from root to leaf
* @return the root of the newly built tree
*/
public static FieldNode addNodeByPath(
FieldNode fieldNode,
String path) {
if (path == null || path.isEmpty()) {
return fieldNode;
}
boolean found = false;
int index = 0;
String[] ps = path.split("\\.");
FieldNode c = fieldNode;
if (fieldNode != null) {
List currentList = Arrays.asList(c);
while (index < ps.length) {
found = false;
for (FieldNode n : currentList) {
if (n.getFieldName().equals(ps[index])) {
found = true;
// If the matched field is leaf which means all leaves are required, not need to go
// deeper.
if (n.getNodes().isEmpty()) {
return fieldNode;
}
c = n;
currentList = c.getNodes();
break;
}
}
if (found) {
index++;
} else {
break;
}
}
}
if (!found) {
while (index < ps.length) {
FieldNode n = new FieldNode(ps[index]);
if (fieldNode == null) {
// rebuild the tree since original is empty
fieldNode = n;
}
if (c != null) {
c.addFieldNodes(n);
}
c = n;
index++;
}
} else {
if (index == ps.length) {
// Consolidation since all leaves are required.
c.getNodes().clear();
}
}
return fieldNode;
}
}