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;
  
  import java.io.DataOutput;
  
  import org.apache.asterix.common.annotations.MissingNullInOutFunction;
  import org.apache.asterix.formats.nontagged.SerializerDeserializerProvider;
  import org.apache.asterix.om.base.ABoolean;
  import org.apache.asterix.om.functions.BuiltinFunctions;
  import org.apache.asterix.om.functions.IFunctionDescriptor;
  import org.apache.asterix.om.functions.IFunctionDescriptorFactory;
  import org.apache.asterix.om.functions.IFunctionTypeInferer;
  import org.apache.asterix.om.pointables.PointableAllocator;
  import org.apache.asterix.om.pointables.base.IVisitablePointable;
  import org.apache.asterix.om.types.BuiltinType;
  import org.apache.asterix.om.types.IAType;
  import org.apache.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
  import org.apache.asterix.runtime.evaluators.comparisons.DeepEqualAssessor;
  import org.apache.asterix.runtime.functions.FunctionTypeInferers;
  import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
  import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluator;
  import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluatorFactory;
  import org.apache.hyracks.api.context.IEvaluatorContext;
  import org.apache.hyracks.api.dataflow.value.ISerializerDeserializer;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  import org.apache.hyracks.data.std.api.IPointable;
  import org.apache.hyracks.data.std.util.ArrayBackedValueStorage;
  import org.apache.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
  
  @MissingNullInOutFunction
  public class DeepEqualityDescriptor extends AbstractScalarFunctionDynamicDescriptor {
  
      public static final IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {
          @Override
          public IFunctionDescriptor createFunctionDescriptor() {
              return new DeepEqualityDescriptor();
          }
  
          @Override
          public IFunctionTypeInferer createFunctionTypeInferer() {
              return new FunctionTypeInferers.DeepEqualityTypeInferer();
          }
      };
  
      private static final long serialVersionUID = 1L;
      private IAType inputTypeLeft;
      private IAType inputTypeRight;
  
      @Override
      public void setImmutableStates(Object... states) {
          this.inputTypeLeft = (IAType) states[0];
          this.inputTypeRight = (IAType) states[1];
      }
  
      @Override
      public IScalarEvaluatorFactory createEvaluatorFactory(final IScalarEvaluatorFactory[] args) {
          final IScalarEvaluatorFactory evalFactoryLeft = args[0];
          final IScalarEvaluatorFactory evalFactoryRight = args[1];
  
          return new IScalarEvaluatorFactory() {
              private static final long serialVersionUID = 1L;
              @SuppressWarnings("unchecked")
              private final ISerializerDeserializer<ABoolean> boolSerde =
                      SerializerDeserializerProvider.INSTANCE.getSerializerDeserializer(BuiltinType.ABOOLEAN);
  
              @Override
              public IScalarEvaluator createScalarEvaluator(IEvaluatorContext ctx) throws HyracksDataException {
                  final ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
                  final DataOutput out = resultStorage.getDataOutput();
                  final IScalarEvaluator evalLeft = evalFactoryLeft.createScalarEvaluator(ctx);
                  final IScalarEvaluator evalRight = evalFactoryRight.createScalarEvaluator(ctx);
  
                  return new IScalarEvaluator() {
                      private final DeepEqualAssessor deepEqualAssessor = new DeepEqualAssessor();
                      private final PointableAllocator allocator = new PointableAllocator();
                      private final IVisitablePointable pointableLeft = allocator.allocateFieldValue(inputTypeLeft);
                      private final IVisitablePointable pointableRight = allocator.allocateFieldValue(inputTypeRight);
  
                      @Override
                      public void evaluate(IFrameTupleReference tuple, IPointable result) throws HyracksDataException {
                          try {
                              evalLeft.evaluate(tuple, pointableLeft);
                              evalRight.evaluate(tuple, pointableRight);
  
                              if (PointableHelper.checkAndSetMissingOrNull(result, pointableLeft, pointableRight)) {
                                  return;
                              }
  
                              // Using deep equality assessment to assess the equality of the two values
                              boolean isEqual = deepEqualAssessor.isEqual(pointableLeft, pointableRight);
                              ABoolean resultBit = isEqual ? ABoolean.TRUE : ABoolean.FALSE;
  
                              resultStorage.reset();
                              boolSerde.serialize(resultBit, out);
                              result.set(resultStorage);
                          } catch (Exception ioe) {
                              throw HyracksDataException.create(ioe);
                          }
                      }
                  };
              }
          };
      }
  
      @Override
      public FunctionIdentifier getIdentifier() {
          return BuiltinFunctions.DEEP_EQUAL;
      }
  }
  