Sho SHIMIZU | 1df945b | 2014-11-06 18:36:11 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2014 Open Networking Laboratory |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.onlab.onos.net.intent.constraint; |
| 17 | |
| 18 | import com.google.common.base.MoreObjects; |
| 19 | import org.onlab.onos.net.Link; |
| 20 | import org.onlab.onos.net.Path; |
| 21 | import org.onlab.onos.net.intent.Constraint; |
| 22 | import org.onlab.onos.net.resource.LinkResourceService; |
| 23 | |
| 24 | import java.time.Duration; |
| 25 | import java.time.temporal.ChronoUnit; |
| 26 | import java.util.Objects; |
| 27 | |
| 28 | /** |
| 29 | * Constraint that evaluates the latency through a path. |
| 30 | */ |
| 31 | public class LatencyConstraint implements Constraint { |
| 32 | |
| 33 | // TODO: formalize the key for latency all over the codes. |
| 34 | private static final String LATENCY_KEY = "latency"; |
| 35 | |
| 36 | private final Duration latency; |
| 37 | |
| 38 | /** |
| 39 | * Creates a new constraint to keep under specified latency through a path. |
| 40 | * @param latency latency to be kept |
| 41 | */ |
| 42 | public LatencyConstraint(Duration latency) { |
| 43 | this.latency = latency; |
| 44 | } |
| 45 | |
| 46 | public Duration getLatency() { |
| 47 | return latency; |
| 48 | } |
| 49 | |
| 50 | @Override |
| 51 | public double cost(Link link, LinkResourceService resourceService) { |
| 52 | String value = link.annotations().value(LATENCY_KEY); |
| 53 | |
| 54 | double latencyInMicroSec; |
| 55 | try { |
| 56 | latencyInMicroSec = Double.parseDouble(value); |
| 57 | } catch (NumberFormatException e) { |
| 58 | latencyInMicroSec = 1.0; |
| 59 | } |
| 60 | |
| 61 | return latencyInMicroSec; |
| 62 | } |
| 63 | |
| 64 | @Override |
| 65 | public boolean validate(Path path, LinkResourceService resourceService) { |
| 66 | double pathLatency = path.links().stream().mapToDouble(link -> cost(link, resourceService)).sum(); |
| 67 | return Duration.of((long) pathLatency, ChronoUnit.MICROS).compareTo(latency) <= 0; |
| 68 | } |
| 69 | |
| 70 | @Override |
| 71 | public int hashCode() { |
| 72 | return Objects.hash(latency); |
| 73 | } |
| 74 | |
| 75 | @Override |
| 76 | public boolean equals(Object obj) { |
| 77 | if (this == obj) { |
| 78 | return true; |
| 79 | } |
| 80 | |
| 81 | if (!(obj instanceof LatencyConstraint)) { |
| 82 | return false; |
| 83 | } |
| 84 | |
| 85 | final LatencyConstraint that = (LatencyConstraint) obj; |
| 86 | return Objects.equals(this.latency, that.latency); |
| 87 | } |
| 88 | |
| 89 | @Override |
| 90 | public String toString() { |
| 91 | return MoreObjects.toStringHelper(this) |
| 92 | .add("latency", latency) |
| 93 | .toString(); |
| 94 | } |
| 95 | } |