/*
* 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.index;
import com.facebook.presto.operator.DriverContext;
import com.facebook.presto.operator.Operator;
import com.facebook.presto.operator.OperatorContext;
import com.facebook.presto.operator.OperatorFactory;
import com.facebook.presto.spi.Page;
import com.facebook.presto.spi.type.Type;
import com.google.common.collect.ImmutableList;
import com.google.common.util.concurrent.ListenableFuture;
import java.util.List;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
public class PageBufferOperator
implements Operator
{
public static class PageBufferOperatorFactory
implements OperatorFactory
{
private final int operatorId;
private final PageBuffer pageBuffer;
public PageBufferOperatorFactory(int operatorId, PageBuffer pageBuffer)
{
this.operatorId = operatorId;
this.pageBuffer = checkNotNull(pageBuffer, "pageBuffer is null");
}
@Override
public List<Type> getTypes()
{
return ImmutableList.of();
}
@Override
public Operator createOperator(DriverContext driverContext)
{
OperatorContext operatorContext = driverContext.addOperatorContext(operatorId, PageBufferOperator.class.getSimpleName());
return new PageBufferOperator(operatorContext, pageBuffer);
}
@Override
public void close()
{
}
}
private final OperatorContext operatorContext;
private final PageBuffer pageBuffer;
private ListenableFuture<?> blocked = NOT_BLOCKED;
private boolean finished;
public PageBufferOperator(OperatorContext operatorContext, PageBuffer pageBuffer)
{
this.operatorContext = checkNotNull(operatorContext, "operatorContext is null");
this.pageBuffer = checkNotNull(pageBuffer, "pageBuffer is null");
}
@Override
public OperatorContext getOperatorContext()
{
return operatorContext;
}
@Override
public List<Type> getTypes()
{
return ImmutableList.of();
}
@Override
public void finish()
{
finished = true;
}
@Override
public boolean isFinished()
{
updateBlockedIfNecessary();
return finished && blocked == NOT_BLOCKED;
}
@Override
public ListenableFuture<?> isBlocked()
{
updateBlockedIfNecessary();
return blocked;
}
@Override
public boolean needsInput()
{
updateBlockedIfNecessary();
return !finished && blocked == NOT_BLOCKED;
}
private void updateBlockedIfNecessary()
{
if (blocked != NOT_BLOCKED && blocked.isDone()) {
blocked = NOT_BLOCKED;
}
}
@Override
public void addInput(Page page)
{
checkNotNull(page, "page is null");
checkState(blocked == NOT_BLOCKED, "output is already blocked");
ListenableFuture<?> future = pageBuffer.add(page);
if (!future.isDone()) {
this.blocked = future;
}
operatorContext.recordGeneratedOutput(page.getSizeInBytes(), page.getPositionCount());
}
@Override
public Page getOutput()
{
return null;
}
}