/**
 * 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.tajo.engine.function.builtin;

import org.apache.tajo.common.TajoDataTypes;
import org.apache.tajo.engine.function.FunctionContext;
import org.apache.tajo.engine.function.annotation.Description;
import org.apache.tajo.engine.function.annotation.ParamTypes;
import org.apache.tajo.storage.Tuple;

@Description(
  functionName = "avg",
  description = "the mean of a set of numbers.",
  example = "> SELECT avg(expr);",
  returnType = TajoDataTypes.Type.FLOAT8,
  paramTypes = {@ParamTypes(paramTypes = {TajoDataTypes.Type.INT4})}
)
public class AvgInt extends AvgLong {

  public AvgInt() {
    super();
  }

  @Override
  public void eval(FunctionContext ctx, Tuple params) {
    AvgContext avgCtx = (AvgContext) ctx;
    avgCtx.sum += params.get(0).asInt4();
    avgCtx.count++;
  }

}