/*
* 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.operator.aggregation.state.LongDecimalWithOverflowAndLongState;
import com.facebook.presto.operator.aggregation.state.LongDecimalWithOverflowAndLongStateFactory;
import com.facebook.presto.spi.block.BlockBuilder;
import com.facebook.presto.spi.type.DecimalType;
import com.facebook.presto.spi.type.UnscaledDecimal128Arithmetic;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;
import java.math.BigDecimal;
import java.math.BigInteger;
import static com.facebook.presto.operator.aggregation.DecimalAverageAggregation.average;
import static com.facebook.presto.spi.type.DecimalType.createDecimalType;
import static com.facebook.presto.spi.type.UnscaledDecimal128Arithmetic.unscaledDecimal;
import static org.testng.Assert.assertEquals;
@Test(singleThreaded = true)
public class TestDecimalAverageAggregation
{
private static final BigInteger TWO = new BigInteger("2");
private static final DecimalType TYPE = createDecimalType(38, 0);
private LongDecimalWithOverflowAndLongState state;
@BeforeMethod
public void setUp()
{
state = new LongDecimalWithOverflowAndLongStateFactory().createSingleState();
}
@Test
public void testOverflow()
{
addToState(state, TWO.pow(126));
assertEquals(state.getLong(), 1);
assertEquals(state.getOverflow(), 0);
assertEquals(state.getLongDecimal(), unscaledDecimal(TWO.pow(126)));
addToState(state, TWO.pow(126));
assertEquals(state.getLong(), 2);
assertEquals(state.getOverflow(), 1);
assertEquals(state.getLongDecimal(), unscaledDecimal(0));
assertEquals(average(state, TYPE), new BigDecimal(TWO.pow(126)));
}
@Test
public void testUnderflow()
{
addToState(state, TWO.pow(126).negate());
assertEquals(state.getLong(), 1);
assertEquals(state.getOverflow(), 0);
assertEquals(state.getLongDecimal(), unscaledDecimal(TWO.pow(126).negate()));
addToState(state, TWO.pow(126).negate());
assertEquals(state.getLong(), 2);
assertEquals(state.getOverflow(), -1);
assertEquals(UnscaledDecimal128Arithmetic.compare(state.getLongDecimal(), unscaledDecimal(0)), 0);
assertEquals(average(state, TYPE), new BigDecimal(TWO.pow(126).negate()));
}
@Test
public void testUnderflowAfterOverflow()
{
addToState(state, TWO.pow(126));
addToState(state, TWO.pow(126));
addToState(state, TWO.pow(125));
assertEquals(state.getOverflow(), 1);
assertEquals(state.getLongDecimal(), unscaledDecimal(TWO.pow(125)));
addToState(state, TWO.pow(126).negate());
addToState(state, TWO.pow(126).negate());
addToState(state, TWO.pow(126).negate());
assertEquals(state.getOverflow(), 0);
assertEquals(state.getLongDecimal(), unscaledDecimal(TWO.pow(125).negate()));
assertEquals(average(state, TYPE), new BigDecimal(TWO.pow(125).negate().divide(BigInteger.valueOf(6))));
}
@Test
public void testCombineOverflow()
{
addToState(state, TWO.pow(125));
addToState(state, TWO.pow(126));
LongDecimalWithOverflowAndLongState otherState = new LongDecimalWithOverflowAndLongStateFactory().createSingleState();
addToState(otherState, TWO.pow(125));
addToState(otherState, TWO.pow(126));
DecimalAverageAggregation.combine(state, otherState);
assertEquals(state.getLong(), 4);
assertEquals(state.getOverflow(), 1);
assertEquals(state.getLongDecimal(), unscaledDecimal(TWO.pow(126)));
BigInteger expectedAverage = BigInteger.ZERO
.add(TWO.pow(126))
.add(TWO.pow(126))
.add(TWO.pow(125))
.add(TWO.pow(125))
.divide(BigInteger.valueOf(4));
assertEquals(average(state, TYPE), new BigDecimal(expectedAverage));
}
@Test
public void testCombineUnderflow()
{
addToState(state, TWO.pow(125).negate());
addToState(state, TWO.pow(126).negate());
LongDecimalWithOverflowAndLongState otherState = new LongDecimalWithOverflowAndLongStateFactory().createSingleState();
addToState(otherState, TWO.pow(125).negate());
addToState(otherState, TWO.pow(126).negate());
DecimalAverageAggregation.combine(state, otherState);
assertEquals(state.getLong(), 4);
assertEquals(state.getOverflow(), -1);
assertEquals(state.getLongDecimal(), unscaledDecimal(TWO.pow(126).negate()));
BigInteger expectedAverage = BigInteger.ZERO
.add(TWO.pow(126))
.add(TWO.pow(126))
.add(TWO.pow(125))
.add(TWO.pow(125))
.negate()
.divide(BigInteger.valueOf(4));
assertEquals(average(state, TYPE), new BigDecimal(expectedAverage));
}
private static void addToState(LongDecimalWithOverflowAndLongState state, BigInteger value)
{
BlockBuilder blockBuilder = TYPE.createFixedSizeBlockBuilder(1);
TYPE.writeSlice(blockBuilder, unscaledDecimal(value));
DecimalAverageAggregation.inputLongDecimal(TYPE, state, blockBuilder.build(), 0);
}
}