com.facebook.presto.spi.block.SortOrder Maven / Gradle / Ivy
/*
* 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.spi.block;
import com.facebook.presto.spi.type.Type;
public enum SortOrder
{
ASC_NULLS_FIRST(true, true),
ASC_NULLS_LAST(true, false),
DESC_NULLS_FIRST(false, true),
DESC_NULLS_LAST(false, false);
private final boolean ascending;
private final boolean nullsFirst;
SortOrder(boolean ascending, boolean nullsFirst)
{
this.ascending = ascending;
this.nullsFirst = nullsFirst;
}
public boolean isAscending()
{
return ascending;
}
public boolean isNullsFirst()
{
return nullsFirst;
}
/**
* Compares the values at the specified positions.
*/
public int compareBlockValue(Type type, Block leftBlock, int leftPosition, Block rightBlock, int rightPosition)
{
boolean leftIsNull = leftBlock.isNull(leftPosition);
boolean rightIsNull = rightBlock.isNull(rightPosition);
if (leftIsNull && rightIsNull) {
return 0;
}
if (leftIsNull) {
return nullsFirst ? -1 : 1;
}
if (rightIsNull) {
return nullsFirst ? 1 : -1;
}
int result = type.compareTo(leftBlock, leftPosition, rightBlock, rightPosition);
return ascending ? result : -result;
}
}