Unit tests for Objective Tracker

- Fixed a bug in ObjectiveTracker turned up by tests, it
  could not handle an emptry list (it was checking for null only)
- Implemented tests for topology, resource and leadership
  events

Change-Id: I1318a0e8655f5b44b30d2ecb527f665f13d54243

@@ -178,7 +178,7 @@ public class ObjectiveTracker implements ObjectiveTrackerService {
                 return;
             }
 
-            if (event.reasons() == null) {
+            if (event.reasons() == null || event.reasons().isEmpty()) {
                 delegate.triggerCompile(new HashSet<IntentId>(), true);
 
             } else {

+/*
+ * 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;
+
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.junit.TestUtils;
+import org.onosproject.core.IdGenerator;
+import org.onosproject.event.Event;
+import org.onosproject.net.Link;
+import org.onosproject.net.LinkKey;
+import org.onosproject.net.NetTestTools;
+import org.onosproject.net.NetworkResource;
+import org.onosproject.net.intent.Intent;
+import org.onosproject.net.intent.IntentBatchLeaderEvent;
+import org.onosproject.net.intent.IntentBatchListener;
+import org.onosproject.net.intent.IntentId;
+import org.onosproject.net.intent.IntentService;
+import org.onosproject.net.intent.MockIdGenerator;
+import org.onosproject.net.link.LinkEvent;
+import org.onosproject.net.resource.LinkResourceEvent;
+import org.onosproject.net.resource.LinkResourceListener;
+import org.onosproject.net.topology.Topology;
+import org.onosproject.net.topology.TopologyEvent;
+import org.onosproject.net.topology.TopologyListener;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Lists;
+import com.google.common.collect.SetMultimap;
+
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.expect;
+import static org.easymock.EasyMock.replay;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.hasSize;
+import static org.hamcrest.Matchers.is;
+import static org.onosproject.net.NetTestTools.link;
+import org.onlab.junit.TestUtils.TestUtilsException;
+
+/**
+ * Tests for the objective tracker.
+ */
+public class ObjectiveTrackerTest {
+    private static final int WAIT_TIMEOUT_SECONDS = 2;
+    private Topology topology;
+    private ObjectiveTracker tracker;
+    private TestTopologyChangeDelegate delegate;
+    private List<Event> reasons;
+    private TopologyListener listener;
+    private LinkResourceListener linkResourceListener;
+    private IntentBatchListener leaderListener;
+    private IdGenerator mockGenerator;
+
+    /**
+     * Initialization shared by all test cases.
+     *
+     * @throws TestUtilsException if any filed look ups fail
+     */
+    @Before
+    public void setUp() throws TestUtilsException {
+        topology = createMock(Topology.class);
+        tracker = new ObjectiveTracker();
+        delegate = new TestTopologyChangeDelegate();
+        tracker.setDelegate(delegate);
+        reasons = new LinkedList<>();
+        listener = TestUtils.getField(tracker, "listener");
+        linkResourceListener = TestUtils.getField(tracker, "linkResourceListener");
+        leaderListener = TestUtils.getField(tracker, "leaderListener");
+        mockGenerator = new MockIdGenerator();
+        Intent.bindIdGenerator(mockGenerator);
+    }
+
+    /**
+     * Code to clean up shared by all test case.
+     */
+    @After
+    public void tearDown() {
+        tracker.unsetDelegate(delegate);
+        Intent.unbindIdGenerator(mockGenerator);
+    }
+
+    /**
+     * Topology change delegate mock that tracks the events coming into it
+     * and saves them.  It provides a latch so that tests can wait for events
+     * to be generated.
+     */
+    static class TestTopologyChangeDelegate implements TopologyChangeDelegate {
+
+        CountDownLatch latch = new CountDownLatch(1);
+        List<IntentId> intentIdsFromEvent;
+        boolean compileAllFailedFromEvent;
+
+        @Override
+        public void triggerCompile(Iterable<IntentId> intentIds,
+                                   boolean compileAllFailed) {
+            intentIdsFromEvent = Lists.newArrayList(intentIds);
+            compileAllFailedFromEvent = compileAllFailed;
+            latch.countDown();
+        }
+    }
+
+    /**
+     * Mock compilable intent class.
+     */
+    private static class MockIntent extends Intent {
+
+        public MockIntent(Collection<NetworkResource> resources) {
+            super(NetTestTools.APP_ID, resources);
+        }
+
+    }
+
+    /**
+     * Mock installable intent class.
+     */
+    private static class MockInstallableIntent extends Intent {
+        public MockInstallableIntent(Collection<NetworkResource> resources) {
+            super(NetTestTools.APP_ID, resources);
+        }
+
+        @Override
+        public boolean isInstallable() {
+            return true;
+        }
+
+    }
+
+    /**
+     * Tests an event with no associated reasons.
+     *
+     * @throws InterruptedException if the latch wait fails.
+     */
+    @Test
+    public void testEventNoReasons() throws InterruptedException {
+        final TopologyEvent event = new TopologyEvent(
+                TopologyEvent.Type.TOPOLOGY_CHANGED,
+                topology,
+                null);
+
+        listener.event(event);
+        assertThat(
+                delegate.latch.await(WAIT_TIMEOUT_SECONDS, TimeUnit.SECONDS),
+                is(true));
+
+        assertThat(delegate.intentIdsFromEvent, hasSize(0));
+        assertThat(delegate.compileAllFailedFromEvent, is(true));
+    }
+
+    /**
+     * Tests an event for a link down where none of the reasons match
+     * currently installed intents.
+     *
+     * @throws InterruptedException if the latch wait fails.
+     */
+    @Test
+    public void testEventLinkDownNoMatches() throws InterruptedException {
+        final Link link = link("src", 1, "dst", 2);
+        final LinkEvent linkEvent = new LinkEvent(LinkEvent.Type.LINK_REMOVED, link);
+        reasons.add(linkEvent);
+
+        final TopologyEvent event = new TopologyEvent(
+                TopologyEvent.Type.TOPOLOGY_CHANGED,
+                topology,
+                reasons);
+
+        listener.event(event);
+        assertThat(
+                delegate.latch.await(WAIT_TIMEOUT_SECONDS, TimeUnit.SECONDS),
+                is(true));
+
+        assertThat(delegate.intentIdsFromEvent, hasSize(0));
+        assertThat(delegate.compileAllFailedFromEvent, is(false));
+    }
+
+    /**
+     * Tests an event for a link being added.
+     *
+     * @throws InterruptedException if the latch wait fails.
+     */
+    @Test
+    public void testEventLinkAdded() throws InterruptedException {
+        final Link link = link("src", 1, "dst", 2);
+        final LinkEvent linkEvent = new LinkEvent(LinkEvent.Type.LINK_ADDED, link);
+        reasons.add(linkEvent);
+
+        final TopologyEvent event = new TopologyEvent(
+                TopologyEvent.Type.TOPOLOGY_CHANGED,
+                topology,
+                reasons);
+
+        listener.event(event);
+        assertThat(
+                delegate.latch.await(WAIT_TIMEOUT_SECONDS, TimeUnit.SECONDS),
+                is(true));
+
+        assertThat(delegate.intentIdsFromEvent, hasSize(0));
+        assertThat(delegate.compileAllFailedFromEvent, is(true));
+    }
+
+    /**
+     * Tests an event for a link down where the link matches existing intents.
+     *
+     * @throws InterruptedException if the latch wait fails.
+     */
+    @Test
+    public void testEventLinkDownMatch() throws Exception {
+        final Link link = link("src", 1, "dst", 2);
+        final LinkEvent linkEvent = new LinkEvent(LinkEvent.Type.LINK_REMOVED, link);
+        reasons.add(linkEvent);
+
+        final TopologyEvent event = new TopologyEvent(
+                TopologyEvent.Type.TOPOLOGY_CHANGED,
+                topology,
+                reasons);
+
+        final IntentId intentId = IntentId.valueOf(0x333L);
+        Collection<NetworkResource> resources = ImmutableSet.of(link);
+        tracker.addTrackedResources(intentId, resources);
+
+        listener.event(event);
+        assertThat(
+                delegate.latch.await(WAIT_TIMEOUT_SECONDS, TimeUnit.SECONDS),
+                is(true));
+
+        assertThat(delegate.intentIdsFromEvent, hasSize(1));
+        assertThat(delegate.compileAllFailedFromEvent, is(false));
+        assertThat(delegate.intentIdsFromEvent.get(0).toString(),
+                   equalTo("0x333"));
+    }
+
+    /**
+     * Tests a resource available event.
+     *
+     * @throws InterruptedException if the latch wait fails.
+     */
+    @Test
+    public void testResourceEvent() throws Exception {
+        LinkResourceEvent event = new LinkResourceEvent(
+                LinkResourceEvent.Type.ADDITIONAL_RESOURCES_AVAILABLE,
+                new HashSet<>());
+        linkResourceListener.event(event);
+
+        assertThat(
+                delegate.latch.await(WAIT_TIMEOUT_SECONDS, TimeUnit.SECONDS),
+                is(true));
+
+        assertThat(delegate.intentIdsFromEvent, hasSize(0));
+        assertThat(delegate.compileAllFailedFromEvent, is(true));
+    }
+
+    /**
+     * Tests leadership events.
+     *
+     * @throws InterruptedException if the latch wait fails.
+     */
+    @Test
+    public void testLeaderEvents() throws Exception {
+
+        final Link link = link("src", 1, "dst", 2);
+        final List<NetworkResource> resources = ImmutableList.of(link);
+
+        final List<Intent> intents = new LinkedList<>();
+        final List<Intent> installableIntents = new LinkedList<>();
+        installableIntents.add(new MockInstallableIntent(resources));
+        intents.add(new MockIntent(resources));
+
+        final SetMultimap<LinkKey, IntentId> intentsByLink =
+                TestUtils.getField(tracker, "intentsByLink");
+        assertThat(intentsByLink.size(), is(0));
+
+        final IntentService mockIntentManager = createMock(IntentService.class);
+        expect(mockIntentManager
+                .getIntents())
+                .andReturn(intents)
+                .anyTimes();
+        expect(mockIntentManager
+                .getIntent(IntentId.valueOf(0x0)))
+                .andReturn(intents.get(0))
+                .anyTimes();
+        expect(mockIntentManager
+                .getInstallableIntents(IntentId.valueOf(0x1)))
+                .andReturn(installableIntents)
+                .anyTimes();
+        replay(mockIntentManager);
+        tracker.bindIntentService(mockIntentManager);
+
+        final IntentBatchLeaderEvent electedEvent = new IntentBatchLeaderEvent(
+                IntentBatchLeaderEvent.Type.ELECTED, NetTestTools.APP_ID);
+        leaderListener.event(electedEvent);
+        assertThat(intentsByLink.size(), is(1));
+
+        final IntentBatchLeaderEvent bootedEvent = new IntentBatchLeaderEvent(
+                IntentBatchLeaderEvent.Type.BOOTED, NetTestTools.APP_ID);
+        leaderListener.event(bootedEvent);
+        assertThat(intentsByLink.size(), is(0));
+
+        tracker.unbindIntentService(mockIntentManager);
+    }
+}