com.metamx.common.JodaUtils.java Source code

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Here is the source code for com.metamx.common.JodaUtils.java

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/*
 * Copyright 2011,2012 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 com.metamx.common;

import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.metamx.common.guava.Comparators;
import org.joda.time.DateTime;
import org.joda.time.Interval;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.TreeSet;

/**
 */
public class JodaUtils {
    public static ArrayList<Interval> condenseIntervals(Iterable<Interval> intervals) {
        ArrayList<Interval> retVal = Lists.newArrayList();

        TreeSet<Interval> sortedIntervals = Sets.newTreeSet(Comparators.intervalsByStartThenEnd());
        for (Interval interval : intervals) {
            sortedIntervals.add(interval);
        }

        if (sortedIntervals.isEmpty()) {
            return Lists.newArrayList();
        }

        Iterator<Interval> intervalsIter = sortedIntervals.iterator();
        Interval currInterval = intervalsIter.next();
        while (intervalsIter.hasNext()) {
            Interval next = intervalsIter.next();

            if (currInterval.overlaps(next) || currInterval.abuts(next)) {
                currInterval = new Interval(currInterval.getStart(), next.getEnd());
            } else {
                retVal.add(currInterval);
                currInterval = next;
            }
        }
        retVal.add(currInterval);

        return retVal;
    }

    public static Interval umbrellaInterval(Iterable<Interval> intervals) {
        ArrayList<DateTime> startDates = Lists.newArrayList();
        ArrayList<DateTime> endDates = Lists.newArrayList();

        for (Interval interval : intervals) {
            startDates.add(interval.getStart());
            endDates.add(interval.getEnd());
        }

        DateTime minStart = minDateTime(startDates.toArray(new DateTime[] {}));
        DateTime maxEnd = maxDateTime(endDates.toArray(new DateTime[] {}));

        if (minStart == null || maxEnd == null) {
            throw new IllegalArgumentException("Empty list of intervals");
        }
        return new Interval(minStart, maxEnd);
    }

    public static boolean overlaps(final Interval i, Iterable<Interval> intervals) {
        return Iterables.any(intervals, new Predicate<Interval>() {
            @Override
            public boolean apply(Interval input) {
                return input.overlaps(i);
            }
        });

    }

    public static DateTime minDateTime(DateTime... times) {
        if (times == null) {
            return null;
        }

        switch (times.length) {
        case 0:
            return null;
        case 1:
            return times[0];
        default:
            DateTime min = times[0];
            for (int i = 1; i < times.length; ++i) {
                min = min.isBefore(times[i]) ? min : times[i];
            }
            return min;
        }
    }

    public static DateTime maxDateTime(DateTime... times) {
        if (times == null) {
            return null;
        }

        switch (times.length) {
        case 0:
            return null;
        case 1:
            return times[0];
        default:
            DateTime max = times[0];
            for (int i = 1; i < times.length; ++i) {
                max = max.isAfter(times[i]) ? max : times[i];
            }
            return max;
        }
    }
}