/*
* Licensed 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 com.facebook.presto.operator.aggregation;
import com.facebook.presto.spi.block.Block;
import com.facebook.presto.spi.block.BlockBuilder;
import com.facebook.presto.spi.block.BlockBuilderStatus;
import com.facebook.presto.spi.type.DecimalType;
import com.facebook.presto.spi.type.SqlDecimal;
import java.math.BigDecimal;
import static java.math.BigDecimal.ROUND_DOWN;
import static java.math.BigDecimal.ROUND_HALF_UP;
public abstract class AbstractTestDecimalAverageAggregation
extends AbstractTestAggregationFunction
{
protected abstract DecimalType getDecimalType();
@Override
public Block[] getSequenceBlocks(int start, int length)
{
BlockBuilder blockBuilder = getDecimalType().createBlockBuilder(new BlockBuilderStatus(), length);
for (int i = start; i < start + length; i++) {
writeDecimalToBlock(getBigDecimalForCounter(i), blockBuilder);
}
return new Block[] {blockBuilder.build()};
}
protected abstract void writeDecimalToBlock(BigDecimal decimal, BlockBuilder blockBuilder);
private static BigDecimal getBigDecimalForCounter(int i)
{
String iAsString = String.valueOf(Math.abs(i));
return new BigDecimal(String.valueOf(i) + "." + iAsString + iAsString).setScale(2, ROUND_DOWN);
}
@Override
public SqlDecimal getExpectedValue(int start, int length)
{
if (length == 0) {
return null;
}
BigDecimal avg = BigDecimal.ZERO;
for (int i = start; i < start + length; i++) {
avg = avg.add(getBigDecimalForCounter(i));
}
avg = avg.divide(BigDecimal.valueOf(length), ROUND_HALF_UP);
return new SqlDecimal(avg.unscaledValue(), avg.precision(), avg.scale());
}
@Override
protected String getFunctionName()
{
return "avg";
}
}