/*
* 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.type.Type;
import com.facebook.presto.util.array.LongBigArray;
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.facebook.presto.spi.type.BigintType.BIGINT;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
public class RowNumberLimitOperator
implements Operator
{
public static class RowNumberLimitOperatorFactory
implements OperatorFactory
{
private final int operatorId;
private final List<Type> sourceTypes;
private final List<Integer> outputChannels;
private final List<Integer> partitionChannels;
private final int expectedPositions;
private final List<Type> types;
private boolean closed;
private final List<Type> partitionTypes;
private final int maxRowCountPerPartition;
public RowNumberLimitOperatorFactory(
int operatorId,
List<? extends Type> sourceTypes,
List<Integer> outputChannels,
List<Integer> partitionChannels,
List<? extends Type> partitionTypes,
int expectedPositions,
int maxRowCountPerPartition)
{
this.operatorId = operatorId;
this.sourceTypes = ImmutableList.copyOf(sourceTypes);
this.outputChannels = ImmutableList.copyOf(checkNotNull(outputChannels, "outputChannels is null"));
this.partitionChannels = ImmutableList.copyOf(checkNotNull(partitionChannels, "partitionChannels is null"));
this.partitionTypes = ImmutableList.copyOf(checkNotNull(partitionTypes, "partitionTypes is null"));
checkArgument(expectedPositions > 0, "expectedPositions < 0");
this.expectedPositions = expectedPositions;
checkArgument(maxRowCountPerPartition > 0, "maxRowCountPerPartition < 0");
this.maxRowCountPerPartition = maxRowCountPerPartition;
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, RowNumberLimitOperator.class.getSimpleName());
return new RowNumberLimitOperator(
operatorContext,
sourceTypes,
outputChannels,
partitionChannels,
partitionTypes,
expectedPositions,
maxRowCountPerPartition);
}
@Override
public void close()
{
closed = true;
}
}
private final OperatorContext operatorContext;
private boolean finishing;
private final PageBuilder pageBuilder;
private final int[] outputChannels;
private final List<Type> types;
private GroupByIdBlock partitionIds;
private final GroupByHash groupByHash;
private Page inputPage;
private int currentPosition;
private final int maxRowCountPerPartition;
private final LongBigArray partitionRowCount;
public RowNumberLimitOperator(
OperatorContext operatorContext,
List<Type> sourceTypes,
List<Integer> outputChannels,
List<Integer> partitionChannels,
List<Type> partitionTypes,
int expectedPositions,
int maxRowCountPerPartition)
{
this.operatorContext = checkNotNull(operatorContext, "operatorContext is null");
this.outputChannels = Ints.toArray(outputChannels);
this.maxRowCountPerPartition = maxRowCountPerPartition;
this.partitionRowCount = new LongBigArray(0);
this.groupByHash = new GroupByHash(partitionTypes, Ints.toArray(partitionChannels), expectedPositions);
this.types = toTypes(sourceTypes, outputChannels);
this.pageBuilder = new PageBuilder(types);
}
@Override
public OperatorContext getOperatorContext()
{
return operatorContext;
}
@Override
public List<Type> getTypes()
{
return types;
}
@Override
public void finish()
{
finishing = true;
}
@Override
public boolean isFinished()
{
return finishing && pageBuilder.isEmpty();
}
@Override
public ListenableFuture<?> isBlocked()
{
return NOT_BLOCKED;
}
@Override
public boolean needsInput()
{
return !finishing && inputPage == null;
}
@Override
public void addInput(Page page)
{
checkState(!finishing, "Operator is already finishing");
checkNotNull(page, "page is null");
checkState(inputPage == null);
inputPage = page;
partitionIds = groupByHash.getGroupIds(inputPage);
partitionRowCount.ensureCapacity(partitionIds.getGroupCount());
currentPosition = 0;
}
@Override
public Page getOutput()
{
if (inputPage == null) {
return null;
}
while (!pageBuilder.isFull() && currentPosition < inputPage.getPositionCount()) {
long partitionId = partitionIds.getGroupId(currentPosition);
long rowCount = partitionRowCount.get(partitionId);
if (rowCount < maxRowCountPerPartition) {
for (int i = 0; i < outputChannels.length; i++) {
int channel = outputChannels[i];
Type type = types.get(channel);
type.appendTo(inputPage.getBlock(channel), currentPosition, pageBuilder.getBlockBuilder(i));
}
BIGINT.writeLong(pageBuilder.getBlockBuilder(types.size() - 1), rowCount + 1);
partitionRowCount.set(partitionId, rowCount + 1);
}
currentPosition++;
}
if (currentPosition == inputPage.getPositionCount()) {
inputPage = null;
currentPosition = 0;
}
if (pageBuilder.isEmpty()) {
return null;
}
Page page = pageBuilder.build();
pageBuilder.reset();
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));
}
types.add(BIGINT);
return types.build();
}
}