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 java.io.IOException;
  
  import org.apache.asterix.builders.UnorderedListBuilder;
  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.ATypeTag;
  import org.apache.asterix.om.types.AUnorderedListType;
  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 UnorderedListConstructorDescriptor extends AbstractScalarFunctionDynamicDescriptor {
  
      public static final IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {
          @Override
          public IFunctionDescriptor createFunctionDescriptor() {
              return new UnorderedListConstructorDescriptor();
          }
  
          @Override
          public IFunctionTypeInferer createFunctionTypeInferer() {
              return FunctionTypeInferers.SET_EXPRESSION_TYPE;
          }
      };
  
      private static final long serialVersionUID = 1L;
      private AUnorderedListType ultype;
  
      @Override
      public void setImmutableStates(Object... states) {
          this.ultype = (AUnorderedListType) states[0];
      }
  
      @Override
      public FunctionIdentifier getIdentifier() {
          return BuiltinFunctions.UNORDERED_LIST_CONSTRUCTOR;
      }
  
      @Override
      public IScalarEvaluatorFactory createEvaluatorFactory(final IScalarEvaluatorFactory[] args) {
          return new UnorderedListConstructorEvaluatorFactory(args, ultype);
      }
  
      private static class UnorderedListConstructorEvaluatorFactory implements IScalarEvaluatorFactory {
  
          private static final long serialVersionUID = 1L;
          private IScalarEvaluatorFactory[] args;
          private boolean selfDescList = false;
          private boolean homoList = false;
          private AUnorderedListType unorderedlistType;
  
          public UnorderedListConstructorEvaluatorFactory(IScalarEvaluatorFactory[] args, AUnorderedListType type) {
              this.args = args;
              this.unorderedlistType = type;
              if (type == null || type.getItemType() == null || type.getItemType().getTypeTag() == ATypeTag.ANY) {
                  this.selfDescList = true;
              } else {
                  this.homoList = true;
              }
          }
  
          @Override
          public IScalarEvaluator createScalarEvaluator(IEvaluatorContext ctx) throws HyracksDataException {
              final IPointable inputVal = new VoidPointable();
              final IScalarEvaluator[] argEvals = new IScalarEvaluator[args.length];
              for (int i = 0; i < args.length; i++) {
                  argEvals[i] = args[i].createScalarEvaluator(ctx);
              }
  
              return new IScalarEvaluator() {
                  private ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
                  private DataOutput out = resultStorage.getDataOutput();
                  private UnorderedListBuilder builder = new UnorderedListBuilder();
  
                  @Override
                  public void evaluate(IFrameTupleReference tuple, IPointable result) throws HyracksDataException {
                      try {
                          builder.reset(unorderedlistType);
                          if (selfDescList) {
                              this.writeUntypedItems(tuple);
                          }
                          if (homoList) {
                              this.writeTypedItems(tuple);
                          }
                          resultStorage.reset();
                          builder.write(out, true);
                          result.set(resultStorage);
                      } catch (IOException ioe) {
                          throw HyracksDataException.create(ioe);
                      }
                  }
  
                  private void writeUntypedItems(IFrameTupleReference tuple) throws HyracksDataException {
  
                      try {
                          for (int i = 0; i < argEvals.length; i++) {
                              argEvals[i].evaluate(tuple, inputVal);
                              builder.addItem(inputVal);
                          }
                      } catch (IOException ioe) {
                          throw HyracksDataException.create(ioe);
                      }
                  }
  
                  private void writeTypedItems(IFrameTupleReference tuple) throws HyracksDataException {
  
                      try {
                          for (int i = 0; i < argEvals.length; i++) {
                              argEvals[i].evaluate(tuple, inputVal);
                              builder.addItem(inputVal);
                          }
                      } catch (IOException ioe) {
                          throw HyracksDataException.create(ioe);
                      }
                  }
  
              };
  
          }
      }
  }
  