/**
* 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.tajo.plan.function;
import org.apache.tajo.catalog.Column;
import org.apache.tajo.function.Function;
import org.apache.tajo.catalog.json.CatalogGsonHelper;
import org.apache.tajo.catalog.proto.CatalogProtos;
import org.apache.tajo.common.TajoDataTypes.DataType;
import org.apache.tajo.datum.Datum;
import org.apache.tajo.storage.Tuple;
@Deprecated
public abstract class AggFunction<T extends Datum> extends Function<T> {
public AggFunction(Column[] definedArgs) {
super(definedArgs);
}
public abstract FunctionContext newContext();
/**
* Called at the first stage.
* @param ctx
* @param params
*/
public abstract void eval(FunctionContext ctx, Tuple params);
/**
* Called at all stages except the first one.
* @param ctx
* @param part
*/
public void merge(FunctionContext ctx, Tuple part) {
eval(ctx, part);
}
public abstract Datum getPartialResult(FunctionContext ctx);
public abstract DataType getPartialResultType();
public abstract T terminate(FunctionContext ctx);
@Override
public String toJson() {
return CatalogGsonHelper.toJson(this, AggFunction.class);
}
@Override
public CatalogProtos.FunctionType getFunctionType() {
return CatalogProtos.FunctionType.AGGREGATION;
}
}