org.apache.hadoop.hive.ql.parse.LeadLagInfo 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.parse;
import java.util.ArrayList;
import java.util.IdentityHashMap;
import java.util.List;
import java.util.Map;
import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
import org.apache.hadoop.hive.ql.plan.ExprNodeGenericFuncDesc;
/**
* Lead Lag functionality
*/
public class LeadLagInfo {
/**
* list of LL invocations in a Query.
*/
List leadLagExprs;
/**
* map from the Select Expr Node to the LL Function invocations in it.
*/
Map> mapTopExprToLLFunExprs;
private void addLeadLagExpr(ExprNodeGenericFuncDesc llFunc) {
leadLagExprs = leadLagExprs == null ? new ArrayList() : leadLagExprs;
leadLagExprs.add(llFunc);
}
public List getLeadLagExprs() {
return leadLagExprs;
}
public void addLLFuncExprForTopExpr(ExprNodeDesc topExpr, ExprNodeGenericFuncDesc llFuncExpr) {
addLeadLagExpr(llFuncExpr);
mapTopExprToLLFunExprs = mapTopExprToLLFunExprs == null ?
new IdentityHashMap>() : mapTopExprToLLFunExprs;
List funcList = mapTopExprToLLFunExprs.get(topExpr);
if (funcList == null) {
funcList = new ArrayList();
mapTopExprToLLFunExprs.put(topExpr, funcList);
}
funcList.add(llFuncExpr);
}
public List getLLFuncExprsInTopExpr(ExprNodeDesc topExpr) {
if (mapTopExprToLLFunExprs == null) {
return null;
}
return mapTopExprToLLFunExprs.get(topExpr);
}
}