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.constructors;
  
  import java.io.DataOutput;
  
  import org.apache.asterix.builders.RecordBuilder;
  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.types.ARecordType;
  import org.apache.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
  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.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;
  
  public class OpenRecordConstructorDescriptor extends AbstractScalarFunctionDynamicDescriptor {
  
      public static final IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {
          @Override
          public IFunctionDescriptor createFunctionDescriptor() {
              return new OpenRecordConstructorDescriptor();
          }
  
          @Override
          public IFunctionTypeInferer createFunctionTypeInferer() {
              return new FunctionTypeInferers.OpenRecordConstructorTypeInferer();
          }
      };
  
      private static final long serialVersionUID = 1L;
      private ARecordType recType;
      private boolean[] openFields;
  
      @Override
      public void setImmutableStates(Object... states) {
          this.recType = (ARecordType) states[0];
          this.openFields = (boolean[]) states[1];
      }
  
      @Override
      public FunctionIdentifier getIdentifier() {
          return BuiltinFunctions.OPEN_RECORD_CONSTRUCTOR;
      }
  
      @Override
      public IScalarEvaluatorFactory createEvaluatorFactory(final IScalarEvaluatorFactory[] args) {
          return new IScalarEvaluatorFactory() {
              private static final long serialVersionUID = 1L;
  
              @Override
              public IScalarEvaluator createScalarEvaluator(IEvaluatorContext ctx) throws HyracksDataException {
                  int n = args.length / 2;
                  final IScalarEvaluator[] evalNames = new IScalarEvaluator[n];
                  final IScalarEvaluator[] evalFields = new IScalarEvaluator[n];
                  final IPointable fieldNamePointable = new VoidPointable();
                  final IPointable fieldValuePointable = new VoidPointable();
                  for (int i = 0; i < n; i++) {
                      evalNames[i] = args[2 * i].createScalarEvaluator(ctx);
                      evalFields[i] = args[2 * i + 1].createScalarEvaluator(ctx);
                  }
                  final ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
                  final DataOutput out = resultStorage.getDataOutput();
                  return new IScalarEvaluator() {
                      private RecordBuilder recBuilder = new RecordBuilder();
                      private int closedFieldId;
                      private boolean first = true;
  
                      @Override
                      public void evaluate(IFrameTupleReference tuple, IPointable result) throws HyracksDataException {
                          resultStorage.reset();
                          closedFieldId = 0;
                          if (first) {
                              first = false;
                              recBuilder.reset(recType);
                          }
                          recBuilder.init();
                          for (int i = 0; i < evalFields.length; i++) {
                              evalFields[i].evaluate(tuple, fieldValuePointable);
                              boolean openField = openFields[i];
                              if (openField) {
                                  evalNames[i].evaluate(tuple, fieldNamePointable);
                                  recBuilder.addField(fieldNamePointable, fieldValuePointable);
                              } else {
                                  recBuilder.addField(closedFieldId, fieldValuePointable);
                                  closedFieldId++;
                              }
                          }
                          recBuilder.write(out, true);
                          result.set(resultStorage);
                      }
                  };
              }
          };
      }
  
      @Override
      public String toString() {
          return "Open Record Constructor";
      }
  }
  