/**
* 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.udf.generic;
import org.apache.hadoop.hive.ql.exec.WindowFunctionInfo;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator.AggregationBuffer;
import org.apache.hadoop.hive.ql.udf.ptf.WindowingTableFunction;
/**
* A GenericUDAF mode that provides it results as a List to the
* {@link WindowingTableFunction} (so it is a
* {@link WindowFunctionInfo#isPivotResult()} return true) may support this
* interface. If it does then the WindowingTableFunction will ask it for the
* next Result after every aggregate call.
*/
public interface ISupportStreamingModeForWindowing {
Object getNextResult(AggregationBuffer agg) throws HiveException;
/*
* for functions that don't support a Window, this provides the rows remaining to be
* added to output. Functions that return a Window can throw a UnsupportedException,
* this method shouldn't be called. For Ranking fns return 0; lead/lag fns return the
* lead/lag amt.
*/
int getRowsRemainingAfterTerminate() throws HiveException;
public static Object NULL_RESULT = new Object();
}