org.apache.aurora.scheduler.async.preemptor.CachedClusterState.java Source code

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Here is the source code for org.apache.aurora.scheduler.async.preemptor.CachedClusterState.java

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/**
 * 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 org.apache.aurora.scheduler.async.preemptor;

import com.google.common.collect.HashMultimap;
import com.google.common.collect.Multimap;
import com.google.common.collect.Multimaps;
import com.google.common.eventbus.Subscribe;

import org.apache.aurora.scheduler.base.Tasks;
import org.apache.aurora.scheduler.events.PubsubEvent;
import org.apache.aurora.scheduler.events.PubsubEvent.TaskStateChange;

/**
 * A cached view of cluster state, kept up to date by pubsub notifications.
 */
class CachedClusterState implements ClusterState, PubsubEvent.EventSubscriber {

    private final Multimap<String, PreemptionVictim> victims = Multimaps
            .synchronizedMultimap(HashMultimap.<String, PreemptionVictim>create());

    @Override
    public Multimap<String, PreemptionVictim> getSlavesToActiveTasks() {
        return Multimaps.unmodifiableMultimap(victims);
    }

    @Subscribe
    public void taskChangedState(TaskStateChange stateChange) {
        synchronized (victims) {
            String slaveId = stateChange.getTask().getAssignedTask().getSlaveId();
            PreemptionVictim victim = PreemptionVictim.fromTask(stateChange.getTask().getAssignedTask());
            if (Tasks.SLAVE_ASSIGNED_STATES.contains(stateChange.getNewState())) {
                victims.put(slaveId, victim);
            } else {
                victims.remove(slaveId, victim);
            }
        }
    }
}