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 org.apache.asterix.builders.IAsterixListBuilder;
  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.types.AOrderedListType;
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.asterix.om.types.AbstractCollectionType;
  import org.apache.asterix.om.types.IAType;
  import org.apache.asterix.om.types.hierachy.ATypeHierarchy;
  import org.apache.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
  import org.apache.asterix.runtime.functions.FunctionTypeInferers;
  import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
  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.TaggedValuePointable;
  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;
  
  /**
   * <pre>
   * array_repeat(val, num_times) returns a new ordered list with the same item type as the input value.
   *
   * It throws an error at compile time if the number of arguments != 2
   *
   * It returns in order:
   * 1. missing, if any argument is missing.
   * 2. null, if:
   * - any argument is null
   * - num_times is not numeric or it's a floating-point with decimals (3.2) or it's NaN/+-INF or it's negative.
   * 3. otherwise, a new ordered list.
   *
   * </pre>
   */
  
  @MissingNullInOutFunction
  public class ArrayRepeatDescriptor extends AbstractScalarFunctionDynamicDescriptor {
      private static final long serialVersionUID = 1L;
  
      private AbstractCollectionType repeatedValueListType;
  
      public static final IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {
          @Override
          public IFunctionDescriptor createFunctionDescriptor() {
              return new ArrayRepeatDescriptor();
          }
  
          @Override
          public IFunctionTypeInferer createFunctionTypeInferer() {
              return FunctionTypeInferers.SET_ARGUMENTS_TYPE;
          }
      };
  
      @Override
      public void setImmutableStates(Object... states) {
          repeatedValueListType = new AOrderedListType((IAType) states[0], null);
      }
  
      @Override
      public FunctionIdentifier getIdentifier() {
          return BuiltinFunctions.ARRAY_REPEAT;
      }
  
      @Override
      public IScalarEvaluatorFactory createEvaluatorFactory(final IScalarEvaluatorFactory[] args)
              throws AlgebricksException {
          return new IScalarEvaluatorFactory() {
              private static final long serialVersionUID = 1L;
  
              @Override
              public IScalarEvaluator createScalarEvaluator(final IEvaluatorContext ctx) throws HyracksDataException {
                  return new ArrayRepeatEval(args, ctx);
              }
          };
      }
  
      public class ArrayRepeatEval implements IScalarEvaluator {
          private final ArrayBackedValueStorage storage;
          private final IScalarEvaluator repeatedValueEval;
          private final IScalarEvaluator repeatEval;
          private final IPointable repeatedValueArg;
          private final IPointable repeatArg;
          private final TaggedValuePointable repeatArgValue;
          private final IAsterixListBuilder listBuilder;
  
          public ArrayRepeatEval(IScalarEvaluatorFactory[] args, IEvaluatorContext ctx) throws HyracksDataException {
              storage = new ArrayBackedValueStorage();
              repeatedValueEval = args[0].createScalarEvaluator(ctx);
              repeatEval = args[1].createScalarEvaluator(ctx);
              repeatedValueArg = new VoidPointable();
              repeatArg = new VoidPointable();
              repeatArgValue = new TaggedValuePointable();
              listBuilder = new OrderedListBuilder();
          }
  
          @Override
          public void evaluate(IFrameTupleReference tuple, IPointable result) throws HyracksDataException {
              // 1st arg: value to repeat
              repeatedValueEval.evaluate(tuple, repeatedValueArg);
  
              // 2nd arg: number of repetitions
              repeatEval.evaluate(tuple, repeatArg);
  
              if (PointableHelper.checkAndSetMissingOrNull(result, repeatedValueArg, repeatArg)) {
                  return;
              }
  
              repeatArgValue.set(repeatArg);
              if (!ATypeHierarchy.isCompatible(ATypeTag.DOUBLE, ATypeTag.VALUE_TYPE_MAPPING[repeatArgValue.getTag()])) {
                  PointableHelper.setNull(result);
                  return;
              }
              final String name = getIdentifier().getName();
              final double repetitions =
                      ATypeHierarchy.getDoubleValue(name, 1, repeatArg.getByteArray(), repeatArg.getStartOffset());
  
              if (Double.isNaN(repetitions) || Double.isInfinite(repetitions) || Math.floor(repetitions) < repetitions
                      || repetitions < 0) {
                  PointableHelper.setNull(result);
                  return;
              }
              // create list
              listBuilder.reset(repeatedValueListType);
              for (int i = 0; i < repetitions; ++i) {
                  listBuilder.addItem(repeatedValueArg);
              }
              storage.reset();
              listBuilder.write(storage.getDataOutput(), true);
              result.set(storage);
          }
      }
  }
  