| /* |
| * Copyright 2014 Open Networking Laboratory |
| * |
| * 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.onlab.onos.net.intent.constraint; |
| |
| import com.google.common.base.MoreObjects; |
| import org.onlab.onos.net.Link; |
| import org.onlab.onos.net.Path; |
| import org.onlab.onos.net.intent.Constraint; |
| import org.onlab.onos.net.resource.LinkResourceService; |
| |
| import java.time.Duration; |
| import java.time.temporal.ChronoUnit; |
| import java.util.Objects; |
| |
| /** |
| * Constraint that evaluates the latency through a path. |
| */ |
| public class LatencyConstraint implements Constraint { |
| |
| // TODO: formalize the key for latency all over the codes. |
| private static final String LATENCY_KEY = "latency"; |
| |
| private final Duration latency; |
| |
| /** |
| * Creates a new constraint to keep under specified latency through a path. |
| * @param latency latency to be kept |
| */ |
| public LatencyConstraint(Duration latency) { |
| this.latency = latency; |
| } |
| |
| public Duration latency() { |
| return latency; |
| } |
| |
| @Override |
| public double cost(Link link, LinkResourceService resourceService) { |
| String value = link.annotations().value(LATENCY_KEY); |
| |
| double latencyInMicroSec; |
| try { |
| latencyInMicroSec = Double.parseDouble(value); |
| } catch (NumberFormatException e) { |
| latencyInMicroSec = 1.0; |
| } |
| |
| return latencyInMicroSec; |
| } |
| |
| @Override |
| public boolean validate(Path path, LinkResourceService resourceService) { |
| double pathLatency = path.links().stream().mapToDouble(link -> cost(link, resourceService)).sum(); |
| return Duration.of((long) pathLatency, ChronoUnit.MICROS).compareTo(latency) <= 0; |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(latency); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (this == obj) { |
| return true; |
| } |
| |
| if (!(obj instanceof LatencyConstraint)) { |
| return false; |
| } |
| |
| final LatencyConstraint that = (LatencyConstraint) obj; |
| return Objects.equals(this.latency, that.latency); |
| } |
| |
| @Override |
| public String toString() { |
| return MoreObjects.toStringHelper(this) |
| .add("latency", latency) |
| .toString(); |
| } |
| } |