com.facebook.presto.jdbc.internal.spi.FixedPageSource 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.jdbc.internal.spi;
import com.facebook.presto.jdbc.internal.common.Page;
import java.io.IOException;
import java.util.Iterator;
import static java.util.Objects.requireNonNull;
public class FixedPageSource
implements ConnectorPageSource
{
private final Iterator pages;
private long completedBytes;
private long completedPositions;
private long memoryUsageBytes;
private boolean closed;
public FixedPageSource(Iterable pages)
{
this.pages = requireNonNull(pages, "pages is null").iterator();
long memoryUsageBytes = 0;
for (Page page : pages) {
memoryUsageBytes += page.getRetainedSizeInBytes();
}
this.memoryUsageBytes = memoryUsageBytes;
}
@Override
public void close()
throws IOException
{
closed = true;
}
@Override
public long getCompletedBytes()
{
return completedBytes;
}
@Override
public long getCompletedPositions()
{
return completedPositions;
}
@Override
public long getReadTimeNanos()
{
return 0;
}
@Override
public boolean isFinished()
{
return closed || !pages.hasNext();
}
@Override
public Page getNextPage()
{
if (isFinished()) {
return null;
}
Page page = pages.next();
completedBytes += page.getSizeInBytes();
completedPositions += page.getPositionCount();
return page;
}
@Override
public long getSystemMemoryUsage()
{
return memoryUsageBytes;
}
}
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