io.druid.timeline.UnionTimeLineLookup.java Source code

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Here is the source code for io.druid.timeline.UnionTimeLineLookup.java

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/*
 * Druid - a distributed column store.
 * Copyright 2012 - 2015 Metamarkets Group Inc.
 *
 * 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 io.druid.timeline;

import com.google.common.base.Function;
import com.google.common.base.Predicates;
import com.google.common.collect.Iterables;
import com.metamx.common.guava.Comparators;
import io.druid.timeline.partition.PartitionHolder;
import org.joda.time.Interval;

import java.util.Comparator;

public class UnionTimeLineLookup<VersionType, ObjectType> implements TimelineLookup<VersionType, ObjectType> {
    Iterable<TimelineLookup<VersionType, ObjectType>> delegates;

    public UnionTimeLineLookup(Iterable<TimelineLookup<VersionType, ObjectType>> delegates) {
        // delegate can be null in case there is no segment loaded for the dataSource on this node
        this.delegates = Iterables.filter(delegates, Predicates.notNull());
    }

    @Override
    public Iterable<TimelineObjectHolder<VersionType, ObjectType>> lookup(final Interval interval) {
        return Iterables.mergeSorted(Iterables.transform(delegates,
                new Function<TimelineLookup<VersionType, ObjectType>, Iterable<TimelineObjectHolder<VersionType, ObjectType>>>() {
                    @Override
                    public Iterable<TimelineObjectHolder<VersionType, ObjectType>> apply(
                            TimelineLookup<VersionType, ObjectType> input) {
                        return input.lookup(interval);
                    }
                }), new Comparator<TimelineObjectHolder<VersionType, ObjectType>>() {
                    @Override
                    public int compare(TimelineObjectHolder<VersionType, ObjectType> o1,
                            TimelineObjectHolder<VersionType, ObjectType> o2) {
                        return Comparators.intervalsByStartThenEnd().compare(o1.getInterval(), o2.getInterval());
                    }
                });
    }

    public PartitionHolder<ObjectType> findEntry(Interval interval, VersionType version) {
        for (TimelineLookup<VersionType, ObjectType> delegate : delegates) {
            final PartitionHolder<ObjectType> entry = delegate.findEntry(interval, version);
            if (entry != null) {
                return entry;
            }
        }
        return null;
    }
}