/*******************************************************************************
* Copyright 2017 Capital One Services, LLC and Bitwise, Inc.
* Licensed 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 hydrograph.engine.expression.userfunctions;
import hydrograph.engine.expression.utils.ExpressionWrapper;
import hydrograph.engine.transformation.userfunctions.base.AggregateTransformBase;
import hydrograph.engine.transformation.userfunctions.base.ReusableRow;
import java.util.ArrayList;
import java.util.Properties;
/**
* The Class AggregateForExpression .
*
* @author Bitwise
*/
@SuppressWarnings("rawtypes")
public class AggregateForExpression implements AggregateTransformBase {
private ExpressionWrapper expressionWrapper;
private Object accumulatorValue;
public void setValidationAPI(ExpressionWrapper expressionWrapper) {
this.expressionWrapper=expressionWrapper;
}
public AggregateForExpression() {
}
public void init(){
expressionWrapper.getValidationAPI().init(expressionWrapper.getIntialValueExpression());
accumulatorValue = expressionWrapper.getValidationAPI()
.exec(new Object[]{});
}
public void callPrepare(String[] inputFieldNames,String[] inputFieldTypes){
String fieldNames[] = new String[inputFieldNames.length + 1];
String fieldTypes[] = new String[inputFieldTypes.length + 1];
for(int i=0;i<inputFieldNames.length;i++){
fieldNames[i]=inputFieldNames[i];
fieldTypes[i]=inputFieldTypes[i];
}
fieldNames[inputFieldNames.length] = "_accumulator";
fieldTypes[inputFieldNames.length] = "Object";
expressionWrapper.getValidationAPI().init(fieldNames,fieldTypes);
}
@Override
public void prepare(Properties props, ArrayList<String> inputFields,
ArrayList<String> outputFields, ArrayList<String> keyFields) {
}
@Override
public void aggregate(ReusableRow input) {
Object tuples[] = new Object[input.getFieldNames().size() + 1];
int i = 0;
for (; i < input.getFieldNames().size(); i++) {
tuples[i] = input.getField(i);
}
tuples[i] = accumulatorValue;
try {
accumulatorValue = expressionWrapper.getValidationAPI().exec(tuples);
} catch (Exception e) {
throw new RuntimeException("Exception in aggregate expression: "
+ expressionWrapper.getValidationAPI().getExpr() + ".\nRow being processed: "
+ input.toString(), e);
}
}
@Override
public void onCompleteGroup(ReusableRow output) {
output.setField(0, (Comparable) accumulatorValue);
try {
accumulatorValue = expressionWrapper.getValidationAPI()
.execute(expressionWrapper.getIntialValueExpression());
} catch (Exception e) {
throw new RuntimeException(
"Exception in aggregate initial value expression: "
+ expressionWrapper.getIntialValueExpression() + ".", e);
}
}
@Override
public void cleanup() {
}
}