content: /*
   * 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.asterix.runtime.evaluators.functions.records;
  
  import java.io.DataOutput;
  
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.asterix.om.types.BuiltinType;
  import org.apache.asterix.om.types.IAType;
  import org.apache.asterix.runtime.evaluators.functions.CastTypeEvaluator;
  import org.apache.asterix.runtime.evaluators.functions.PointableHelper;
  import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluator;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  import org.apache.hyracks.data.std.api.IPointable;
  import org.apache.hyracks.data.std.primitive.VoidPointable;
  import org.apache.hyracks.data.std.util.ArrayBackedValueStorage;
  import org.apache.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
  
  abstract class AbstractRecordPairsEvaluator implements IScalarEvaluator {
      protected final IScalarEvaluator eval0;
      protected final IPointable inputPointable = new VoidPointable();
      protected final ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
      protected final DataOutput resultOutput = resultStorage.getDataOutput();
      private CastTypeEvaluator inputCaster;
  
      AbstractRecordPairsEvaluator(IScalarEvaluator eval0, IAType inputType) {
          this.eval0 = eval0;
          if (inputType != null) {
              inputCaster = new CastTypeEvaluator(BuiltinType.ANY, inputType, eval0, null);
          }
      }
  
      @Override
      public void evaluate(IFrameTupleReference tuple, IPointable result) throws HyracksDataException {
          eval0.evaluate(tuple, inputPointable);
  
          if (PointableHelper.checkAndSetMissingOrNull(result, inputPointable)) {
              return;
          }
  
          final ATypeTag inputTypeTag = PointableHelper.getTypeTag(inputPointable);
          if (!validateInputType(inputTypeTag)) {
              PointableHelper.setNull(result);
              return;
          }
          inputCaster.evaluate(tuple, inputPointable);
          resultStorage.reset();
          buildOutput();
          result.set(resultStorage);
      }
  
      protected abstract boolean validateInputType(ATypeTag inputTypeTag);
  
      protected abstract void buildOutput() throws HyracksDataException;
  }
  