/**
* 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.parse;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.metastore.api.FieldSchema;
import org.apache.hadoop.hive.ql.exec.Task;
import org.apache.hadoop.hive.ql.exec.TaskFactory;
import org.apache.hadoop.hive.ql.plan.ExplainWork;
/**
* ExplainSemanticAnalyzer.
*
*/
public class ExplainSemanticAnalyzer extends BaseSemanticAnalyzer {
List<FieldSchema> fieldList;
public ExplainSemanticAnalyzer(HiveConf conf) throws SemanticException {
super(conf);
}
@Override
public void analyzeInternal(ASTNode ast) throws SemanticException {
ctx.setExplain(true);
// Create a semantic analyzer for the query
BaseSemanticAnalyzer sem = SemanticAnalyzerFactory.get(conf, (ASTNode) ast
.getChild(0));
sem.analyze((ASTNode) ast.getChild(0), ctx);
sem.validate();
boolean extended = false;
boolean formatted = false;
if (ast.getChildCount() == 2) {
int explainOptions = ast.getChild(1).getType();
formatted = (explainOptions == HiveParser.KW_FORMATTED);
extended = (explainOptions == HiveParser.KW_EXTENDED);
}
ctx.setResFile(new Path(ctx.getLocalTmpFileURI()));
List<Task<? extends Serializable>> tasks = sem.getRootTasks();
Task<? extends Serializable> fetchTask = sem.getFetchTask();
if (tasks == null) {
if (fetchTask != null) {
tasks = new ArrayList<Task<? extends Serializable>>();
tasks.add(fetchTask);
}
} else if (fetchTask != null) {
tasks.add(fetchTask);
}
Task<? extends Serializable> explTask =
TaskFactory.get(new ExplainWork(ctx.getResFile().toString(),
tasks,
((ASTNode) ast.getChild(0)).toStringTree(),
extended,
formatted),
conf);
fieldList = explTask.getResultSchema();
rootTasks.add(explTask);
}
@Override
public List<FieldSchema> getResultSchema() {
return fieldList;
}
}