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 java.io.IOException;
  
  import org.apache.asterix.builders.OrderedListBuilder;
  import org.apache.asterix.common.annotations.MissingNullInOutFunction;
  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.typecomputer.impl.TypeComputeUtils;
  import org.apache.asterix.om.types.AOrderedListType;
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.asterix.om.types.IAType;
  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;
  
  @MissingNullInOutFunction
  public class ToArrayDescriptor extends AbstractScalarFunctionDynamicDescriptor {
      public static final IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {
          @Override
          public IFunctionDescriptor createFunctionDescriptor() {
              return new ToArrayDescriptor();
          }
  
          @Override
          public IFunctionTypeInferer createFunctionTypeInferer() {
              return FunctionTypeInferers.SET_EXPRESSION_TYPE;
          }
      };
  
      private static final long serialVersionUID = 1L;
      private AOrderedListType oltype;
  
      @Override
      public void setImmutableStates(Object... states) {
          oltype = TypeComputeUtils.extractOrderedListType((IAType) states[0]);
      }
  
      @Override
      public IScalarEvaluatorFactory createEvaluatorFactory(final IScalarEvaluatorFactory[] args) {
          return new IScalarEvaluatorFactory() {
              private static final long serialVersionUID = 1L;
  
              @Override
              public IScalarEvaluator createScalarEvaluator(final IEvaluatorContext ctx) throws HyracksDataException {
  
                  return new IScalarEvaluator() {
  
                      private final IScalarEvaluator eval0 = args[0].createScalarEvaluator(ctx);
                      private final IPointable arg0 = new VoidPointable();
                      private final OrderedListBuilder listBuilder = new OrderedListBuilder();
                      private final ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
                      private final DataOutput out = resultStorage.getDataOutput();
  
                      @Override
                      public void evaluate(IFrameTupleReference tuple, IPointable resultPointable)
                              throws HyracksDataException {
                          eval0.evaluate(tuple, arg0);
  
                          if (PointableHelper.checkAndSetMissingOrNull(resultPointable, arg0)) {
                              return;
                          }
  
                          byte[] data = arg0.getByteArray();
                          int offset = arg0.getStartOffset();
                          if (data[offset] == ATypeTag.SERIALIZED_ORDEREDLIST_TYPE_TAG) {
                              resultPointable.set(arg0);
                          } else if (data[offset] == ATypeTag.SERIALIZED_UNORDEREDLIST_TYPE_TAG) {
                              try {
                                  resultStorage.reset();
                                  out.writeByte(ATypeTag.SERIALIZED_ORDEREDLIST_TYPE_TAG);
                                  out.write(data, offset + 1, arg0.getLength() - 1);
                                  resultPointable.set(resultStorage);
                              } catch (IOException e) {
                                  throw HyracksDataException.create(e);
                              }
                          } else {
                              resultStorage.reset();
                              listBuilder.reset(oltype);
                              listBuilder.addItem(arg0);
                              listBuilder.write(out, true);
                              resultPointable.set(resultStorage);
                          }
                      }
                  };
              }
          };
      }
  
      @Override
      public FunctionIdentifier getIdentifier() {
          return BuiltinFunctions.TO_ARRAY;
      }
  }
  