/*
* 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.project;
import com.facebook.presto.spi.ConnectorSession;
import com.facebook.presto.spi.Page;
public interface PageFilter
{
boolean isDeterministic();
InputChannels getInputChannels();
SelectedPositions filter(ConnectorSession session, Page page);
static SelectedPositions positionsArrayToSelectedPositions(boolean[] selectedPositions, int size)
{
int selectedCount = 0;
for (int i = 0; i < size; i++) {
boolean selectedPosition = selectedPositions[i];
if (selectedPosition) {
selectedCount++;
}
}
if (selectedCount == 0 || selectedCount == size) {
return SelectedPositions.positionsRange(0, selectedCount);
}
int[] positions = new int[selectedCount];
int index = 0;
for (int position = 0; position < size; position++) {
if (selectedPositions[position]) {
positions[index] = position;
index++;
}
}
return SelectedPositions.positionsList(positions, 0, selectedCount);
}
}