/*
* 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.Page;
import com.facebook.presto.spi.PageBuilder;
import com.facebook.presto.spi.block.SortOrder;
import com.facebook.presto.spi.type.Type;
import com.google.common.collect.ImmutableList;
import com.google.common.primitives.Ints;
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 OrderByOperator
implements Operator
{
public static class OrderByOperatorFactory
implements OperatorFactory
{
private final int operatorId;
private final List<Type> sortTypes;
private final List<Type> sourceTypes;
private final List<Integer> outputChannels;
private final int expectedPositions;
private final List<Integer> sortChannels;
private final List<SortOrder> sortOrder;
private final List<Type> types;
private boolean closed;
public OrderByOperatorFactory(
int operatorId,
List<? extends Type> sourceTypes,
List<Integer> outputChannels,
int expectedPositions,
List<Integer> sortChannels,
List<SortOrder> sortOrder)
{
this.operatorId = operatorId;
this.sourceTypes = ImmutableList.copyOf(checkNotNull(sourceTypes, "sourceTypes is null"));
ImmutableList.Builder<Type> sortTypes = ImmutableList.builder();
for (int channel : sortChannels) {
sortTypes.add(sourceTypes.get(channel));
}
this.sortTypes = sortTypes.build();
this.outputChannels = checkNotNull(outputChannels, "outputChannels is null");
this.expectedPositions = expectedPositions;
this.sortChannels = ImmutableList.copyOf(checkNotNull(sortChannels, "sortChannels is null"));
this.sortOrder = ImmutableList.copyOf(checkNotNull(sortOrder, "sortOrder is null"));
this.types = toTypes(sourceTypes, outputChannels);
}
@Override
public List<Type> getTypes()
{
return types;
}
@Override
public Operator createOperator(DriverContext driverContext)
{
checkState(!closed, "Factory is already closed");
OperatorContext operatorContext = driverContext.addOperatorContext(operatorId, OrderByOperator.class.getSimpleName());
return new OrderByOperator(
operatorContext,
sourceTypes,
outputChannels,
expectedPositions,
sortTypes,
sortChannels,
sortOrder);
}
@Override
public void close()
{
closed = true;
}
}
private enum State
{
NEEDS_INPUT,
HAS_OUTPUT,
FINISHED
}
private final OperatorContext operatorContext;
private final List<Type> sortTypes;
private final List<Integer> sortChannels;
private final List<SortOrder> sortOrder;
private final int[] outputChannels;
private final List<Type> types;
private final PagesIndex pageIndex;
private final PageBuilder pageBuilder;
private int currentPosition;
private State state = State.NEEDS_INPUT;
public OrderByOperator(
OperatorContext operatorContext,
List<Type> sourceTypes,
List<Integer> outputChannels,
int expectedPositions,
List<Type> sortTypes,
List<Integer> sortChannels,
List<SortOrder> sortOrder)
{
this.operatorContext = checkNotNull(operatorContext, "operatorContext is null");
this.outputChannels = Ints.toArray(checkNotNull(outputChannels, "outputChannels is null"));
this.types = toTypes(sourceTypes, outputChannels);
this.sortTypes = ImmutableList.copyOf(checkNotNull(sortTypes, "sortTypes is null"));
this.sortChannels = ImmutableList.copyOf(checkNotNull(sortChannels, "sortChannels is null"));
this.sortOrder = ImmutableList.copyOf(checkNotNull(sortOrder, "sortOrder is null"));
this.pageIndex = new PagesIndex(sourceTypes, expectedPositions, operatorContext);
this.pageBuilder = new PageBuilder(this.types);
}
@Override
public OperatorContext getOperatorContext()
{
return operatorContext;
}
@Override
public List<Type> getTypes()
{
return types;
}
@Override
public void finish()
{
if (state == State.NEEDS_INPUT) {
state = State.HAS_OUTPUT;
// sort the index
pageIndex.sort(sortTypes, sortChannels, sortOrder);
}
}
@Override
public boolean isFinished()
{
return state == State.FINISHED;
}
@Override
public ListenableFuture<?> isBlocked()
{
return NOT_BLOCKED;
}
@Override
public boolean needsInput()
{
return state == State.NEEDS_INPUT;
}
@Override
public void addInput(Page page)
{
checkState(state == State.NEEDS_INPUT, "Operator is already finishing");
checkNotNull(page, "page is null");
pageIndex.addPage(page);
}
@Override
public Page getOutput()
{
if (state != State.HAS_OUTPUT) {
return null;
}
if (currentPosition >= pageIndex.getPositionCount()) {
state = State.FINISHED;
return null;
}
// iterate through the positions sequentially until we have one full page
pageBuilder.reset();
currentPosition = pageIndex.buildPage(currentPosition, outputChannels, pageBuilder);
// output the page if we have any data
if (pageBuilder.isEmpty()) {
state = State.FINISHED;
return null;
}
Page page = pageBuilder.build();
return page;
}
private static List<Type> toTypes(List<? extends Type> sourceTypes, List<Integer> outputChannels)
{
ImmutableList.Builder<Type> types = ImmutableList.builder();
for (int channel : outputChannels) {
types.add(sourceTypes.get(channel));
}
return types.build();
}
}