Receive PDP status messages

Added infrastructure code to facilitate receipt and tracking of
PDP status messages.

Removed temporary PdpStatus class.

Use variable for pdp-common version.

Change-Id: Id76c45f26b6d9f5eb9395332b637a0b1e90bc496
Issue-ID: POLICY-1444
Signed-off-by: Jim Hahn <jrh3@att.com>

2 files changed, 178 insertions, 0 deletions

diff --git a/main/src/test/java/org/onap/policy/pap/main/comm/MultiPdpStatusListenerTest.java b/main/src/test/java/org/onap/policy/pap/main/comm/MultiPdpStatusListenerTest.java
new file mode 100644
index 00000000..2dc1aa2c
--- /dev/null
+++ b/main/src/test/java/org/onap/policy/pap/main/comm/MultiPdpStatusListenerTest.java
@@ -0,0 +1,177 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP PAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.pap.main.comm;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.junit.Test;
+import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
+import org.onap.policy.pap.main.comm.MultiPdpStatusListener;
+import org.onap.policy.pdp.common.models.PdpStatus;
+
+public class MultiPdpStatusListenerTest {
+    private static final CommInfrastructure INFRA = CommInfrastructure.NOOP;
+    private static final String TOPIC = "my-topic";
+    private static final String NAME1 = "pdp_1";
+    private static final String NAME2 = "pdp_2";
+    private static final List<String> NAME_LIST = Arrays.asList(NAME1, NAME2);
+
+    private MultiPdpStatusListener listener;
+    private PdpStatus status;
+
+    @Test
+    public void testMultiPdpStatusListenerString() throws Exception {
+        listener = new MultiPdpStatusListener(NAME1);
+        assertEquals(Arrays.asList(NAME1).toString(), listener.getUnseenPdpNames().toString());
+
+        // a name is in the queue - not done yet
+        assertFalse(doWait(0));
+    }
+
+    @Test
+    public void testMultiPdpStatusListenerCollectionOfString() throws Exception {
+        List<String> lst = NAME_LIST;
+
+        listener = new MultiPdpStatusListener(lst);
+        assertEquals(lst.toString(), listener.getUnseenPdpNames().toString());
+
+        // a name is in the queue - not done yet
+        assertFalse(doWait(0));
+
+        /*
+         * Try with an empty list - should already be complete.
+         */
+        listener = new MultiPdpStatusListener(new LinkedList<>());
+        assertTrue(listener.getUnseenPdpNames().isEmpty());
+        assertTrue(doWait(0));
+    }
+
+    @Test
+    public void testGetUnseenPdpNames() {
+        List<String> lst = NAME_LIST;
+
+        listener = new MultiPdpStatusListener(lst);
+        assertEquals(lst.toString(), listener.getUnseenPdpNames().toString());
+
+        // receive message from one PDP
+        status = new PdpStatus();
+        status.setName(NAME2);
+        listener.onTopicEvent(INFRA, TOPIC, status);
+        assertEquals(Arrays.asList(NAME1).toString(), listener.getUnseenPdpNames().toString());
+
+        // receive message from the other PDP
+        status = new PdpStatus();
+        status.setName(NAME1);
+        listener.onTopicEvent(INFRA, TOPIC, status);
+        assertTrue(listener.getUnseenPdpNames().isEmpty());
+    }
+
+    @Test
+    public void testAwait() throws Exception {
+        // try with an empty list - should already be complete
+        listener = new MultiPdpStatusListener(new LinkedList<>());
+        assertTrue(doWait(0));
+
+        // try it with something in the list
+        listener = new MultiPdpStatusListener(NAME_LIST);
+        assertFalse(doWait(0));
+
+        // process a message from one PDP - wait should block the entire time
+        status = new PdpStatus();
+        status.setName(NAME1);
+        listener.onTopicEvent(INFRA, TOPIC, status);
+        long tbeg = System.currentTimeMillis();
+        assertFalse(doWait(50));
+        assertTrue(System.currentTimeMillis() - tbeg >= 49);
+
+        // process a message from the other PDP - wait should NOT block
+        status = new PdpStatus();
+        status.setName(NAME2);
+        listener.onTopicEvent(INFRA, TOPIC, status);
+        tbeg = System.currentTimeMillis();
+        assertTrue(doWait(4000));
+        assertTrue(System.currentTimeMillis() - tbeg < 3000);
+    }
+
+    @Test
+    public void testOnTopicEvent() throws Exception {
+        listener = new MultiPdpStatusListener(NAME_LIST);
+
+        // not done yet
+        assertFalse(doWait(0));
+
+        // process a message - still not done as have another name to go
+        status = new PdpStatus();
+        status.setName(NAME1);
+        listener.onTopicEvent(INFRA, TOPIC, status);
+        assertFalse(doWait(0));
+
+        // process a message from the same PDP - still not done
+        status = new PdpStatus();
+        status.setName(NAME1);
+        listener.onTopicEvent(INFRA, TOPIC, status);
+        assertFalse(doWait(0));
+
+        // process another message - now we're done
+        status = new PdpStatus();
+        status.setName(NAME2);
+        listener.onTopicEvent(INFRA, TOPIC, status);
+        assertTrue(doWait(0));
+    }
+
+    /**
+     * Waits for the listener to complete. Spawns a background thread to do the waiting so
+     * we can limit how long we wait.
+     *
+     * @param millisec milliseconds to wait
+     * @return {@code true} if the wait completed successfully, {@code false} otherwise
+     * @throws InterruptedException if this thread is interrupted while waiting for the
+     *         background thread to complete
+     */
+    private boolean doWait(long millisec) throws InterruptedException {
+        AtomicBoolean done = new AtomicBoolean(false);
+
+        Thread thread = new Thread() {
+            @Override
+            public void run() {
+                try {
+                    done.set(listener.await(millisec, TimeUnit.MILLISECONDS));
+
+                } catch (InterruptedException expected) {
+                    return;
+                }
+            }
+        };
+
+        thread.start();
+        thread.join(5000);
+        thread.interrupt();
+
+        return done.get();
+    }
+}
diff --git a/main/src/test/java/org/onap/policy/pap/main/comm/PdpClientExceptionTest.java b/main/src/test/java/org/onap/policy/pap/main/comm/PdpClientExceptionTest.java
index dcaba782..aa927665 100644
--- a/main/src/test/java/org/onap/policy/pap/main/comm/PdpClientExceptionTest.java
+++ b/main/src/test/java/org/onap/policy/pap/main/comm/PdpClientExceptionTest.java
@@ -24,6 +24,7 @@ import static org.junit.Assert.assertEquals;
 
 import org.junit.Test;
 import org.onap.policy.common.utils.test.ExceptionsTester;
+import org.onap.policy.pap.main.comm.PdpClientException;
 
 public class PdpClientExceptionTest {