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.calcite.sql.fun;
  
  import org.apache.calcite.rel.type.RelDataType;
  import org.apache.calcite.rel.type.RelDataTypeFactory;
  import org.apache.calcite.sql.SqlAggFunction;
  import org.apache.calcite.sql.SqlFunctionCategory;
  import org.apache.calcite.sql.SqlKind;
  import org.apache.calcite.sql.SqlSplittableAggFunction;
  import org.apache.calcite.sql.type.OperandTypes;
  import org.apache.calcite.sql.type.ReturnTypes;
  import org.apache.calcite.util.Optionality;
  
  import com.google.common.collect.ImmutableList;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.util.List;
  
  /**
   * <code>Sum</code> is an aggregator which returns the sum of the values which
   * go into it. It has precisely one argument of numeric type (<code>int</code>,
   * <code>long</code>, <code>float</code>, <code>double</code>), and the result
   * is the same type.
   */
  public class SqlSumAggFunction extends SqlAggFunction {
  
    //~ Instance fields --------------------------------------------------------
  
    @Deprecated // to be removed before 2.0
    private final RelDataType type;
  
    //~ Constructors -----------------------------------------------------------
  
    public SqlSumAggFunction(RelDataType type) {
      super(
          "SUM",
          null,
          SqlKind.SUM,
          ReturnTypes.AGG_SUM,
          null,
          OperandTypes.NUMERIC,
          SqlFunctionCategory.NUMERIC,
          false,
          false,
          Optionality.FORBIDDEN);
      this.type = type;
    }
  
    //~ Methods ----------------------------------------------------------------
  
    @SuppressWarnings("deprecation")
    @Override public List<RelDataType> getParameterTypes(RelDataTypeFactory typeFactory) {
      return ImmutableList.of(type);
    }
  
    @Deprecated // to be removed before 2.0
    public RelDataType getType() {
      return type;
    }
  
    @SuppressWarnings("deprecation")
    @Override public RelDataType getReturnType(RelDataTypeFactory typeFactory) {
      return type;
    }
  
    @Override public <T extends Object> @Nullable T unwrap(Class<T> clazz) {
      if (clazz.isInstance(SqlSplittableAggFunction.SumSplitter.INSTANCE)) {
        return clazz.cast(SqlSplittableAggFunction.SumSplitter.INSTANCE);
      }
      return super.unwrap(clazz);
    }
  
    @Override public SqlAggFunction getRollup() {
      return this;
    }
  }
  