org.apache.druid.client.selector.AbstractTierSelectorStrategy.java Source code

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Here is the source code for org.apache.druid.client.selector.AbstractTierSelectorStrategy.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.druid.client.selector;

import com.google.common.collect.Iterables;
import it.unimi.dsi.fastutil.ints.Int2ObjectRBTreeMap;
import org.apache.druid.timeline.DataSegment;

import javax.annotation.Nullable;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;

/**
 */
public abstract class AbstractTierSelectorStrategy implements TierSelectorStrategy {
    private final ServerSelectorStrategy serverSelectorStrategy;

    public AbstractTierSelectorStrategy(ServerSelectorStrategy serverSelectorStrategy) {
        this.serverSelectorStrategy = serverSelectorStrategy;
    }

    @Nullable
    @Override
    public QueryableDruidServer pick(Int2ObjectRBTreeMap<Set<QueryableDruidServer>> prioritizedServers,
            DataSegment segment) {
        return Iterables.getOnlyElement(pick(prioritizedServers, segment, 1), null);
    }

    @Override
    public List<QueryableDruidServer> pick(Int2ObjectRBTreeMap<Set<QueryableDruidServer>> prioritizedServers,
            DataSegment segment, int numServersToPick) {
        List<QueryableDruidServer> result = new ArrayList<>(numServersToPick);
        for (Set<QueryableDruidServer> priorityServers : prioritizedServers.values()) {
            result.addAll(serverSelectorStrategy.pick(priorityServers, segment, numServersToPick - result.size()));
            if (result.size() == numServersToPick) {
                break;
            }
        }
        return result;
    }
}