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.runningaggregates.std;
  
  import org.apache.asterix.formats.nontagged.SerializerDeserializerProvider;
  import org.apache.asterix.om.base.AInt64;
  import org.apache.asterix.om.base.AMutableInt64;
  import org.apache.asterix.om.types.BuiltinType;
  import org.apache.hyracks.algebricks.runtime.base.IWindowAggregateEvaluator;
  import org.apache.hyracks.api.dataflow.value.ISerializerDeserializer;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  import org.apache.hyracks.data.std.api.IPointable;
  import org.apache.hyracks.data.std.util.ArrayBackedValueStorage;
  import org.apache.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
  
  /**
   * Evaluator for {@code row_number()} window function
   */
  class RowNumberRunningAggregateEvaluator implements IWindowAggregateEvaluator {
  
      @SuppressWarnings("unchecked")
      private final ISerializerDeserializer<AInt64> serde =
              SerializerDeserializerProvider.INSTANCE.getSerializerDeserializer(BuiltinType.AINT64);
  
      private final ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
  
      private final AMutableInt64 aInt64 = new AMutableInt64(0);
  
      private long resultValue;
  
      @Override
      public void init() {
          // nothing to do
      }
  
      @Override
      public void initPartition(long partitionLength) {
          resultValue = 0;
      }
  
      @Override
      public void step(IFrameTupleReference tuple, IPointable result) throws HyracksDataException {
          resultValue++;
  
          resultStorage.reset();
          aInt64.setValue(resultValue);
          serde.serialize(aInt64, resultStorage.getDataOutput());
          result.set(resultStorage);
      }
  }
  