io.druid.indexing.overlord.scaling.ScalingStats.java Source code

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Here is the source code for io.druid.indexing.overlord.scaling.ScalingStats.java

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/*
 * Druid - a distributed column store.
 * Copyright (C) 2012, 2013  Metamarkets Group Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

package io.druid.indexing.overlord.scaling;

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonValue;
import com.google.common.collect.Lists;
import com.google.common.collect.MinMaxPriorityQueue;
import org.joda.time.DateTime;

import java.util.Collections;
import java.util.Comparator;
import java.util.List;

/**
 */
public class ScalingStats {
    public static enum EVENT {
        PROVISION, TERMINATE
    }

    private static final Comparator<ScalingEvent> comparator = new Comparator<ScalingEvent>() {
        @Override
        public int compare(ScalingEvent s1, ScalingEvent s2) {
            return -s1.getTimestamp().compareTo(s2.getTimestamp());
        }
    };

    private final Object lock = new Object();

    private final MinMaxPriorityQueue<ScalingEvent> recentEvents;

    public ScalingStats(int capacity) {
        if (capacity == 0) {
            this.recentEvents = MinMaxPriorityQueue.orderedBy(comparator).create();
        } else {
            this.recentEvents = MinMaxPriorityQueue.orderedBy(comparator).maximumSize(capacity).create();
        }
    }

    public void addProvisionEvent(AutoScalingData data) {
        synchronized (lock) {
            recentEvents.add(new ScalingEvent(data, new DateTime(), EVENT.PROVISION));
        }
    }

    public void addTerminateEvent(AutoScalingData data) {
        synchronized (lock) {
            recentEvents.add(new ScalingEvent(data, new DateTime(), EVENT.TERMINATE));
        }
    }

    @JsonValue
    public List<ScalingEvent> toList() {
        synchronized (lock) {
            List<ScalingEvent> retVal = Lists.newArrayList(recentEvents);
            Collections.sort(retVal, comparator);
            return retVal;
        }
    }

    public static class ScalingEvent {
        private final AutoScalingData data;
        private final DateTime timestamp;
        private final EVENT event;

        private ScalingEvent(AutoScalingData data, DateTime timestamp, EVENT event) {
            this.data = data;
            this.timestamp = timestamp;
            this.event = event;
        }

        @JsonProperty
        public AutoScalingData getData() {
            return data;
        }

        @JsonProperty
        public DateTime getTimestamp() {
            return timestamp;
        }

        @JsonProperty
        public EVENT getEvent() {
            return event;
        }

        @Override
        public String toString() {
            return "ScalingEvent{" + "data=" + data + ", timestamp=" + timestamp + ", event=" + event + '}';
        }
    }
}