/**
* Licensed to Odiago, Inc. under one or more contributor license
* agreements. See the NOTICE.txt file distributed with this work for
* additional information regarding copyright ownership. Odiago, Inc.
* 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 com.odiago.flumebase.exec;
import java.io.IOException;
import java.math.BigDecimal;
import java.util.List;
import org.apache.avro.Schema;
import org.apache.avro.generic.GenericData;
import com.odiago.flumebase.parser.AliasedExpr;
import com.odiago.flumebase.parser.Expr;
import com.odiago.flumebase.parser.TypedField;
/**
* Evaluate a set of expressions giving computed output field values.
*/
public class EvaluationElement extends AvroOutputElementImpl {
/** The expressions to evaluate. */
private List<AliasedExpr> mExprs;
/** Additional fields to propagate forward. */
private List<TypedField> mPropagateFields;
public EvaluationElement(FlowElementContext ctxt, List<AliasedExpr> exprs,
List<TypedField> propagateFields, Schema outputSchema) {
super(ctxt, outputSchema);
mExprs = exprs;
mPropagateFields = propagateFields;
}
@Override
public void takeEvent(EventWrapper e) throws IOException, InterruptedException {
GenericData.Record record = new GenericData.Record(getOutputSchema());
// Evaluate all our input expressions, left-to-right, and emit
// their results into the output record.
for (AliasedExpr aliasedExpr : mExprs) {
Expr expr = aliasedExpr.getExpr();
Object result = nativeToAvro(expr.eval(e), expr.getResolvedType());
String fieldName = aliasedExpr.getAvroLabel();
record.put(fieldName, result);
}
// Now add to our output record, any fields that we can pull in directly from
// the propagation layer.
for (TypedField field : mPropagateFields) {
String fieldName = field.getAvroName();
record.put(fieldName, e.getField(field));
}
emitAvroRecord(record, e.getEvent());
}
}