/**
* 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.drill.exec.ref.eval.fn.agg;
import org.apache.drill.exec.ref.RecordPointer;
import org.apache.drill.exec.ref.eval.EvaluatorTypes.AggregatingEvaluator;
import org.apache.drill.exec.ref.eval.EvaluatorTypes.BasicEvaluator;
import org.apache.drill.exec.ref.eval.fn.FunctionArguments;
import org.apache.drill.exec.ref.eval.fn.FunctionEvaluator;
import org.apache.drill.exec.ref.values.DataValue;
import org.apache.drill.exec.ref.values.ScalarValues;
@FunctionEvaluator("count")
public class CountAggregator implements AggregatingEvaluator{
static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(CountAggregator.class);
boolean isConstant;
long l = 0;
boolean checkForNull = false;
BasicEvaluator child;
public CountAggregator(RecordPointer inputRecord, FunctionArguments e) {
isConstant = e.isOnlyConstants();
if(!e.getOnlyEvaluator().isConstant()){
checkForNull = true;
child = e.getOnlyEvaluator();
}
}
@Override
public void addRecord() {
if(checkForNull){
if(child.eval() != DataValue.NULL_VALUE){
l++;
}
}else{
l++;
}
}
@Override
public DataValue eval() {
DataValue v = new ScalarValues.LongScalar(l);
l = 0;
return v;
}
@Override
public boolean isConstant() {
return isConstant;
}
}