| /* |
| * 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.onosproject.net.intent.impl.compiler; |
| |
| import com.google.common.base.Predicate; |
| import com.google.common.collect.FluentIterable; |
| import com.google.common.collect.ImmutableList; |
| import org.apache.felix.scr.annotations.Component; |
| import org.apache.felix.scr.annotations.Reference; |
| import org.apache.felix.scr.annotations.ReferenceCardinality; |
| import org.onosproject.net.ElementId; |
| import org.onosproject.net.Path; |
| import org.onosproject.net.intent.ConnectivityIntent; |
| import org.onosproject.net.intent.Constraint; |
| import org.onosproject.net.intent.IntentCompiler; |
| import org.onosproject.net.intent.IntentExtensionService; |
| import org.onosproject.net.intent.impl.PathNotFoundException; |
| import org.onosproject.net.provider.ProviderId; |
| import org.onosproject.net.resource.LinkResourceService; |
| import org.onosproject.net.topology.LinkWeight; |
| import org.onosproject.net.topology.PathService; |
| import org.onosproject.net.topology.TopologyEdge; |
| |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Set; |
| |
| /** |
| * Base class for compilers of various |
| * {@link org.onosproject.net.intent.ConnectivityIntent connectivity intents}. |
| */ |
| @Component(immediate = true) |
| public abstract class ConnectivityIntentCompiler<T extends ConnectivityIntent> |
| implements IntentCompiler<T> { |
| |
| private static final ProviderId PID = new ProviderId("core", "org.onosproject.core", true); |
| |
| @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY) |
| protected IntentExtensionService intentManager; |
| |
| @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY) |
| protected PathService pathService; |
| |
| @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY) |
| protected LinkResourceService resourceService; |
| |
| /** |
| * Returns an edge-weight capable of evaluating links on the basis of the |
| * specified constraints. |
| * |
| * @param constraints path constraints |
| * @return edge-weight function |
| */ |
| protected LinkWeight weight(List<Constraint> constraints) { |
| return new ConstraintBasedLinkWeight(constraints); |
| } |
| |
| /** |
| * Validates the specified path against the given constraints. |
| * |
| * @param path path to be checked |
| * @param constraints path constraints |
| * @return true if the path passes all constraints |
| */ |
| protected boolean checkPath(Path path, List<Constraint> constraints) { |
| for (Constraint constraint : constraints) { |
| if (!constraint.validate(path, resourceService)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Computes a path between two ConnectPoints. |
| * |
| * @param intent intent on which behalf path is being computed |
| * @param one start of the path |
| * @param two end of the path |
| * @return Path between the two |
| * @throws PathNotFoundException if a path cannot be found |
| */ |
| protected Path getPath(ConnectivityIntent intent, |
| ElementId one, ElementId two) { |
| Set<Path> paths = pathService.getPaths(one, two, weight(intent.constraints())); |
| final List<Constraint> constraints = intent.constraints(); |
| ImmutableList<Path> filtered = FluentIterable.from(paths) |
| .filter(new Predicate<Path>() { |
| @Override |
| public boolean apply(Path path) { |
| return checkPath(path, constraints); |
| } |
| }).toList(); |
| if (filtered.isEmpty()) { |
| throw new PathNotFoundException(one, two); |
| } |
| // TODO: let's be more intelligent about this eventually |
| return filtered.iterator().next(); |
| } |
| |
| /** |
| * Edge-weight capable of evaluating link cost using a set of constraints. |
| */ |
| protected class ConstraintBasedLinkWeight implements LinkWeight { |
| |
| private final List<Constraint> constraints; |
| |
| /** |
| * Creates a new edge-weight function capable of evaluating links |
| * on the basis of the specified constraints. |
| * |
| * @param constraints path constraints |
| */ |
| ConstraintBasedLinkWeight(List<Constraint> constraints) { |
| if (constraints == null) { |
| this.constraints = Collections.emptyList(); |
| } else { |
| this.constraints = ImmutableList.copyOf(constraints); |
| } |
| } |
| |
| @Override |
| public double weight(TopologyEdge edge) { |
| if (!constraints.iterator().hasNext()) { |
| return 1.0; |
| } |
| |
| // iterate over all constraints in order and return the weight of |
| // the first one with fast fail over the first failure |
| Iterator<Constraint> it = constraints.iterator(); |
| |
| double cost = it.next().cost(edge.link(), resourceService); |
| while (it.hasNext() && cost > 0) { |
| if (it.next().cost(edge.link(), resourceService) < 0) { |
| return -1; |
| } |
| } |
| return cost; |
| |
| } |
| } |
| |
| } |