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.IOException;
  
  import org.apache.asterix.builders.IAsterixListBuilder;
  import org.apache.asterix.formats.nontagged.BinaryComparatorFactoryProvider;
  import org.apache.asterix.om.functions.BuiltinFunctions;
  import org.apache.asterix.om.functions.IFunctionDescriptorFactory;
  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.common.ListAccessor;
  import org.apache.asterix.runtime.functions.FunctionTypeInferers;
  import org.apache.asterix.runtime.utils.DescriptorFactoryUtil;
  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.dataflow.value.IBinaryComparator;
  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;
  
  /**
   * <pre>
   * array_put(list, val1, val2, ...) returns a new list with all the values appended to the input list items only if
   * the list does not already have the value. Values cannot be null (i.e., one cannot append nulls).
   * array_put([2, 3], 2, 2, 9, 9) will result in [2, 3, 9, 9].
   *
   * It throws an error at compile time if the number of arguments < 2
   *
   * It returns (or throws an error at runtime) in order:
   * 1. missing, if any argument is missing.
   * 2. null, if any argument is null.
   * 3. otherwise, a new list.
   *
   * </pre>
   */
  public class ArrayPutDescriptor extends AbstractScalarFunctionDynamicDescriptor {
      private static final long serialVersionUID = 1L;
      private IAType[] argTypes;
  
      public static final IFunctionDescriptorFactory FACTORY =
              DescriptorFactoryUtil.createFactory(ArrayPutDescriptor::new, FunctionTypeInferers.SET_ARGUMENTS_TYPE);
  
      @Override
      public FunctionIdentifier getIdentifier() {
          return BuiltinFunctions.ARRAY_PUT;
      }
  
      @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 ArrayPutEval(args, ctx);
              }
          };
      }
  
      @Override
      public void setImmutableStates(Object... states) {
          argTypes = (IAType[]) states;
      }
  
      public class ArrayPutEval extends AbstractArrayAddRemoveEval {
          private final ArrayBackedValueStorage storage;
          private final IPointable item;
          private final IBinaryComparator comp;
          private final boolean[] add;
  
          ArrayPutEval(IScalarEvaluatorFactory[] args, IEvaluatorContext ctx) throws HyracksDataException {
              super(args, ctx, 0, 1, args.length - 1, argTypes, true, false);
              // input list will be opened since makeOpen=true. all values will be opened, too. hence ANY for comp.
              comp = BinaryComparatorFactoryProvider.INSTANCE
                      .getBinaryComparatorFactory(BuiltinType.ANY, BuiltinType.ANY, true).createBinaryComparator();
              storage = new ArrayBackedValueStorage();
              item = new VoidPointable();
              add = new boolean[args.length - 1];
          }
  
          @Override
          protected void processList(ListAccessor listAccessor, IAsterixListBuilder listBuilder, IPointable[] values,
                  int position) throws IOException {
              markAllToBeAdded();
              // get the list items one by one and append to the new list
              for (int i = 0; i < listAccessor.size(); i++) {
                  listAccessor.getOrWriteItem(i, item, storage);
                  listBuilder.addItem(item);
                  // mark the equal values to skip adding them
                  for (int j = 0; j < values.length; j++) {
                      if (add[j] && comp.compare(item.getByteArray(), item.getStartOffset(), item.getLength(),
                              values[j].getByteArray(), values[j].getStartOffset(), values[j].getLength()) == 0) {
                          add[j] = false;
                      }
                      // skip comparison if the value is already marked
                  }
              }
              // append the values arguments only if they are not already present in the list, i.e. not marked
              for (int i = 0; i < values.length; i++) {
                  if (add[i]) {
                      listBuilder.addItem(values[i]);
                  }
              }
          }
  
          private void markAllToBeAdded() {
              for (int i = 0; i < add.length; i++) {
                  add[i] = true;
              }
          }
      }
  }
  