1 files changed, 159 insertions, 0 deletions
diff --git a/appc-event-listener/appc-event-listener-bundle/src/main/java/org/openecomp/appc/listener/AbstractListener.java b/appc-event-listener/appc-event-listener-bundle/src/main/java/org/openecomp/appc/listener/AbstractListener.java
new file mode 100644
index 000000000..b36f4d7e6
--- /dev/null
+++ b/appc-event-listener/appc-event-listener-bundle/src/main/java/org/openecomp/appc/listener/AbstractListener.java
@@ -0,0 +1,159 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * openECOMP : APP-C
+ * ================================================================================
+ * Copyright (C) 2017 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.openecomp.appc.listener;
+
+import java.security.SecureRandom;
+import java.util.concurrent.ArrayBlockingQueue;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.RejectedExecutionHandler;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import org.apache.commons.lang3.concurrent.BasicThreadFactory;
+import org.openecomp.appc.listener.impl.EventHandlerImpl;
+
+import com.att.eelf.configuration.EELFLogger;
+import com.att.eelf.configuration.EELFManager;
+
+public abstract class AbstractListener implements Listener {
+
+    private final EELFLogger LOG = EELFManager.getInstance().getLogger(AbstractListener.class);
+
+    protected AtomicBoolean run = new AtomicBoolean(false);
+
+    protected int QUEUED_MIN = 1;
+    protected int QUEUED_MAX = 10;
+
+    protected int THREAD_MIN = 4;
+    protected int THREAD_MAX = THREAD_MIN; // Fixed thread pool
+    protected int THREAD_SCALE_DOWN_SEC = 10; // Number of seconds to wait until we remove idle threads
+
+    protected ThreadPoolExecutor executor;
+
+    protected EventHandler dmaap;
+
+    protected ListenerProperties props;
+
+    private String listenerId;
+
+    public AbstractListener(ListenerProperties props) {
+        updateProperties(props);
+
+        dmaap = new EventHandlerImpl(props);
+        if (dmaap.getClientId().equals("0")) {
+        	dmaap.setClientId(String.valueOf(new SecureRandom().nextInt(1000)));
+        }
+
+        BlockingQueue<Runnable> threadQueue = new ArrayBlockingQueue<Runnable>(QUEUED_MAX + QUEUED_MIN + 1);
+        executor = new ThreadPoolExecutor(THREAD_MIN, THREAD_MAX, THREAD_SCALE_DOWN_SEC, TimeUnit.SECONDS, threadQueue,
+            new JobRejectionHandler());
+
+        // Custom Named thread factory
+        BasicThreadFactory threadFactory = new BasicThreadFactory.Builder().namingPattern("DMaaP-Worker-%d").build();
+        executor.setThreadFactory(threadFactory);
+
+        run.set(true);
+    }
+
+    /**
+     * Starts a loop that will only end after stop() or stopNow() are called. The loop will read messages off the DMaaP
+     * topic and perform some action on them while writing messages back to DMaaP at critical points in the execution.
+     * Inherited from Runnable.
+     * 
+     * @see java.lang.Runnable#run()
+     */
+    @Override
+    public void run() {
+        LOG.error("Listener.run() has not been implemented");
+    }
+
+    @Override
+    public void stop() {
+        run.set(false);
+        LOG.info(String.format("Stopping with %d messages in queue", executor.getQueue().size()));
+        executor.shutdown();
+        try {
+            executor.awaitTermination(10, TimeUnit.SECONDS);
+        } catch (InterruptedException e) {
+            LOG.error("Listener graceful stop() failed", e);
+        }
+        
+        // close DMaaP clients
+        if (dmaap != null) {
+        	dmaap.closeClients();
+        }
+        LOG.info("Listener Thread Pool Finished");
+    }
+
+    @Override
+    public void stopNow() {
+        run.set(false);
+        LOG.info(String.format("StopNow called. Orphaning %d messages in the queue", executor.getQueue().size()));
+        executor.getQueue().clear();
+        stop();
+    }
+
+    @Override
+    public String getBenchmark() {
+        return String.format("%s - No benchmarking implemented.", getListenerId());
+    }
+
+    @Override
+    public String getListenerId() {
+        return listenerId;
+    }
+
+    // Sets the id of the listener in
+    @Override
+    public void setListenerId(String id) {
+        listenerId = id;
+    }
+
+    private void updateProperties(ListenerProperties properties) {
+        this.props = properties;
+        QUEUED_MIN =
+            Integer.valueOf(props.getProperty(ListenerProperties.KEYS.THREADS_MIN_QUEUE, String.valueOf(QUEUED_MIN)));
+        QUEUED_MAX =
+            Integer.valueOf(props.getProperty(ListenerProperties.KEYS.THREADS_MAX_QUEUE, String.valueOf(QUEUED_MAX)));
+        THREAD_MIN =
+            Integer.valueOf(props.getProperty(ListenerProperties.KEYS.THREADS_MIN_POOL, String.valueOf(THREAD_MIN)));
+        THREAD_MAX =
+            Integer.valueOf(props.getProperty(ListenerProperties.KEYS.THREADS_MAX_POOL, String.valueOf(THREAD_MAX)));
+
+        listenerId = props.getPrefix();
+    }
+
+    /**
+     * This class will be used to handle what happens when we cannot add a job because of a ThreadPool issue. It does
+     * not get invoked if there is any fault with the job. NOTE: So far, this has only been seen when doing a
+     * {@link Listener#stopNow}
+     *
+     */
+    class JobRejectionHandler implements RejectedExecutionHandler {
+        @Override
+        public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
+            LOG.error(String.format("A job was rejected. [%s]", r));
+        }
+
+    }
+}