/*
* 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;
import com.facebook.presto.spi.block.RandomAccessBlock;
import com.facebook.presto.spi.block.SortOrder;
import com.google.common.collect.ImmutableList;
import java.util.List;
import static com.facebook.presto.operator.SyntheticAddress.decodePosition;
import static com.facebook.presto.operator.SyntheticAddress.decodeSliceIndex;
import static com.google.common.base.Preconditions.checkNotNull;
public class SimplePagesIndexComparator
implements PagesIndexComparator
{
private final List<Integer> sortChannels;
private final List<SortOrder> sortOrders;
public SimplePagesIndexComparator(List<Integer> sortChannels, List<SortOrder> sortOrders)
{
this.sortChannels = ImmutableList.copyOf(checkNotNull(sortChannels, "sortChannels is null"));
this.sortOrders = ImmutableList.copyOf(checkNotNull(sortOrders, "sortOrders is null"));
}
@Override
public int compareTo(PagesIndex pagesIndex, int leftPosition, int rightPosition)
{
long leftPageAddress = pagesIndex.getValueAddresses().getLong(leftPosition);
int leftBlockIndex = decodeSliceIndex(leftPageAddress);
int leftBlockPosition = decodePosition(leftPageAddress);
long rightPageAddress = pagesIndex.getValueAddresses().getLong(rightPosition);
int rightBlockIndex = decodeSliceIndex(rightPageAddress);
int rightBlockPosition = decodePosition(rightPageAddress);
for (int i = 0; i < sortChannels.size(); i++) {
int sortChannel = sortChannels.get(i);
RandomAccessBlock leftBlock = pagesIndex.getChannel(sortChannel).get(leftBlockIndex);
RandomAccessBlock rightBlock = pagesIndex.getChannel(sortChannel).get(rightBlockIndex);
int compare = leftBlock.compareTo(sortOrders.get(i), leftBlockPosition, rightBlock, rightBlockPosition);
if (compare != 0) {
return compare;
}
}
return 0;
}
}