/**
 * 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.preemptor;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.Multimap;

/**
 * A facade for the preemptor to gain access to the state of scheduled tasks in the cluster.
 */
@VisibleForTesting
public interface ClusterState {

  /**
   * Gets a snapshot of the active tasks in the cluster, indexed by the slave IDs they are
   * assigned to.
   * <p>
   * TODO(wfarner): Return a more minimal type than IAssignedTask here.
   *
   * @return Active tasks and their associated slave IDs.
   */
  Multimap<String, PreemptionVictim> getSlavesToActiveTasks();
}