org.apache.aurora.scheduler.filter.AttributeFilter.java Source code

Introduction

Here is the source code for org.apache.aurora.scheduler.filter.AttributeFilter.java

Source

/**
 * 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;
    }
}