content: /**
   * 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.filter;
  
  import java.util.Set;
  
  import com.google.common.base.Predicates;
  import com.google.common.collect.Iterables;
  
  import org.apache.aurora.scheduler.storage.entities.IAttribute;
  import org.apache.aurora.scheduler.storage.entities.IValueConstraint;
  
  /**
   * Utility class that matches attributes to constraints.
   */
  final class AttributeFilter {
  
    private AttributeFilter() {
      // Utility class.
    }
  
    /**
     * Tests whether a constraint is satisfied by attributes.
     *
     * @param values Host attribute values.
     * @param constraint Constraint to match.
     * @return {@code true} if the attribute satisfies the constraint, {@code false} otherwise.
     */
    static boolean matches(Set<String> values, IValueConstraint constraint) {
      boolean match = Iterables.any(constraint.getValues(), Predicates.in(values));
      return constraint.isNegated() ^ match;
    }
  
    /**
     * Tests whether an attribute matches a limit constraint.
     *
     * @param attribute Attribute to match against.
     * @param limit Limit value.
     * @param attributeAggregate Cached state of the job being filtered.
     * @return {@code true} if the limit constraint is satisfied, {@code false} otherwise.
     */
    static boolean matches(
        final IAttribute attribute,
        int limit,
        AttributeAggregate attributeAggregate) {
  
      for (String value : attribute.getValues()) {
        if (limit <= attributeAggregate.getNumTasksWithAttribute(attribute.getName(), value)) {
          return false;
        }
      }
  
      return true;
    }
  }
  