1 files changed, 152 insertions, 0 deletions
diff --git a/framework/src/onos/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/ConnectivityIntentCompiler.java b/framework/src/onos/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/ConnectivityIntentCompiler.java
new file mode 100644
index 00000000..6de4cfdc
--- /dev/null
+++ b/framework/src/onos/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/ConnectivityIntentCompiler.java
@@ -0,0 +1,152 @@
+/*
+ * Copyright 2014-2015 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.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.link.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(path -> 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;
+
+        }
+    }
+
+}