/*
* 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.split;
import com.facebook.presto.spi.ConnectorPageSource;
import com.facebook.presto.spi.Page;
import com.facebook.presto.spi.block.Block;
import com.google.common.primitives.Ints;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;
import static java.util.Objects.requireNonNull;
public class MappedPageSource
implements ConnectorPageSource
{
private final ConnectorPageSource delegate;
private final int[] delegateFieldIndex;
public MappedPageSource(ConnectorPageSource delegate, List<Integer> delegateFieldIndex)
{
this.delegate = requireNonNull(delegate, "delegate is null");
this.delegateFieldIndex = Ints.toArray(requireNonNull(delegateFieldIndex, "delegateFieldIndex is null"));
}
@Override
public long getTotalBytes()
{
return delegate.getTotalBytes();
}
@Override
public long getCompletedBytes()
{
return delegate.getCompletedBytes();
}
@Override
public long getReadTimeNanos()
{
return delegate.getReadTimeNanos();
}
@Override
public boolean isFinished()
{
return delegate.isFinished();
}
@Override
public Page getNextPage()
{
Page nextPage = delegate.getNextPage();
if (nextPage == null) {
return null;
}
Block[] blocks = Arrays.stream(delegateFieldIndex)
.mapToObj(nextPage::getBlock)
.toArray(Block[]::new);
return new Page(nextPage.getPositionCount(), blocks);
}
@Override
public long getSystemMemoryUsage()
{
return delegate.getSystemMemoryUsage();
}
@Override
public void close()
throws IOException
{
delegate.close();
}
}