/*
* 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.plugin.blackhole;
import com.facebook.presto.spi.BucketFunction;
import com.facebook.presto.spi.ConnectorSession;
import com.facebook.presto.spi.ConnectorSplit;
import com.facebook.presto.spi.Node;
import com.facebook.presto.spi.NodeManager;
import com.facebook.presto.spi.PrestoException;
import com.facebook.presto.spi.connector.ConnectorNodePartitioningProvider;
import com.facebook.presto.spi.connector.ConnectorPartitioningHandle;
import com.facebook.presto.spi.connector.ConnectorTransactionHandle;
import com.facebook.presto.spi.type.Type;
import com.google.common.collect.ImmutableMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.ToIntFunction;
import static com.facebook.presto.spi.StandardErrorCode.NOT_SUPPORTED;
import static java.util.Objects.requireNonNull;
public class BlackHoleNodePartitioningProvider
implements ConnectorNodePartitioningProvider
{
private final NodeManager nodeManager;
public BlackHoleNodePartitioningProvider(NodeManager nodeManager)
{
this.nodeManager = requireNonNull(nodeManager, "nodeManager is null");
}
@Override
public Map<Integer, Node> getBucketToNode(ConnectorTransactionHandle transactionHandle, ConnectorSession session, ConnectorPartitioningHandle partitioningHandle)
{
Set<Node> nodes = nodeManager.getRequiredWorkerNodes();
// create on part per node
ImmutableMap.Builder<Integer, Node> distribution = ImmutableMap.builder();
int partNumber = 0;
for (Node node : nodes) {
distribution.put(partNumber, node);
partNumber++;
}
return distribution.build();
}
@Override
public ToIntFunction<ConnectorSplit> getSplitBucketFunction(
ConnectorTransactionHandle transactionHandle,
ConnectorSession session,
ConnectorPartitioningHandle partitioningHandle)
{
return value -> {
throw new PrestoException(NOT_SUPPORTED, "Black hole connector does not supported distributed reads");
};
}
@Override
public BucketFunction getBucketFunction(
ConnectorTransactionHandle transactionHandle,
ConnectorSession session,
ConnectorPartitioningHandle partitioningHandle,
List<Type> partitionChannelTypes, int bucketCount)
{
return (page, position) -> {
long hash = 13;
for (int i = 0; i < partitionChannelTypes.size(); i++) {
Type type = partitionChannelTypes.get(i);
hash = 31 * hash + type.hash(page.getBlock(i), position);
}
// clear the sign bit
hash &= 0x7fff_ffff_ffff_ffffL;
return (int) (hash % bucketCount);
};
}
}