Adding services engine module

Change-Id: I68bbe6d95d17cfcdda204d1ee3eec3b92d12ebd4
Issue-ID: POLICY-859
Signed-off-by: waqas.ikram <waqas.ikram@ericsson.com>

1 files changed, 218 insertions, 0 deletions

diff --git a/services/services-engine/src/main/java/org/onap/policy/apex/service/engine/event/impl/eventrequestor/EventRequestorConsumer.java b/services/services-engine/src/main/java/org/onap/policy/apex/service/engine/event/impl/eventrequestor/EventRequestorConsumer.java
new file mode 100644
index 000000000..b472cc9c7
--- /dev/null
+++ b/services/services-engine/src/main/java/org/onap/policy/apex/service/engine/event/impl/eventrequestor/EventRequestorConsumer.java
@@ -0,0 +1,218 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.service.engine.event.impl.eventrequestor;
+
+import java.util.EnumMap;
+import java.util.Map;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.TimeUnit;
+
+import org.onap.policy.apex.core.infrastructure.threading.ApplicationThreadFactory;
+import org.onap.policy.apex.core.infrastructure.threading.ThreadUtilities;
+import org.onap.policy.apex.service.engine.event.ApexEventConsumer;
+import org.onap.policy.apex.service.engine.event.ApexEventException;
+import org.onap.policy.apex.service.engine.event.ApexEventReceiver;
+import org.onap.policy.apex.service.engine.event.ApexEventRuntimeException;
+import org.onap.policy.apex.service.engine.event.PeeredReference;
+import org.onap.policy.apex.service.parameters.eventhandler.EventHandlerParameters;
+import org.onap.policy.apex.service.parameters.eventhandler.EventHandlerPeeredMode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * This class implements an Apex event consumer that receives events from its peered event requestor
+ * producer.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class EventRequestorConsumer implements ApexEventConsumer, Runnable {
+    // Get a reference to the logger
+    private static final Logger LOGGER = LoggerFactory.getLogger(EventRequestorConsumer.class);
+
+    // The amount of time to wait in milliseconds between checks that the consumer thread has
+    // stopped
+    private static final long EVENT_REQUESTOR_WAIT_SLEEP_TIME = 50;
+
+    // The event receiver that will receive events from this consumer
+    private ApexEventReceiver eventReceiver;
+
+    // The name for this consumer
+    private String name = null;
+
+    // The peer references for this event handler
+    private final Map<EventHandlerPeeredMode, PeeredReference> peerReferenceMap =
+            new EnumMap<>(EventHandlerPeeredMode.class);
+
+    // Temporary request holder for incoming event send requests
+    private final BlockingQueue<Object> incomingEventRequestQueue = new LinkedBlockingQueue<>();
+
+    // The consumer thread and stopping flag
+    private Thread consumerThread;
+    private boolean stopOrderedFlag = false;
+
+    // The number of events received to date
+    private int eventsReceived = 0;
+
+    @Override
+    public void init(final String consumerName, final EventHandlerParameters consumerParameters,
+            final ApexEventReceiver incomingEventReceiver) throws ApexEventException {
+        this.eventReceiver = incomingEventReceiver;
+        this.name = consumerName;
+
+        // Check and get the event requestor consumer properties
+        if (!(consumerParameters
+                .getCarrierTechnologyParameters() instanceof EventRequestorCarrierTechnologyParameters)) {
+            final String errorMessage =
+                    "specified consumer properties are not applicable to event Requestor consumer (" + this.name + ")";
+            LOGGER.warn(errorMessage);
+            throw new ApexEventException(errorMessage);
+        }
+
+        // Check if we are in peered mode
+        if (!consumerParameters.isPeeredMode(EventHandlerPeeredMode.REQUESTOR)) {
+            final String errorMessage = "event Requestor consumer (" + this.name
+                    + ") must run in peered requestor mode with a event Requestor producer";
+            LOGGER.warn(errorMessage);
+            throw new ApexEventException(errorMessage);
+        }
+
+    }
+
+    /**
+     * Receive an incoming event send request from the peered event Requestor producer and queue it
+     * 
+     * @param eventObject the incoming event to process
+     * @throws ApexEventRuntimeException on queueing errors
+     */
+    public void processEvent(final Object eventObject) {
+        // Push the event onto the queue for handling
+        try {
+            incomingEventRequestQueue.add(eventObject);
+        } catch (final Exception e) {
+            final String errorMessage =
+                    "could not queue request \"" + eventObject + "\" on event Requestor consumer (" + this.name + ")";
+            LOGGER.warn(errorMessage);
+            throw new ApexEventRuntimeException(errorMessage);
+        }
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.onap.policy.apex.service.engine.event.ApexEventConsumer#start()
+     */
+    @Override
+    public void start() {
+        // Configure and start the event reception thread
+        final String threadName = this.getClass().getName() + ":" + this.name;
+        consumerThread = new ApplicationThreadFactory(threadName).newThread(this);
+        consumerThread.setDaemon(true);
+        consumerThread.start();
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.onap.policy.apex.service.engine.event.ApexEventConsumer#getName()
+     */
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    /**
+     * Get the number of events received to date
+     * 
+     * @return the number of events received
+     */
+    public int getEventsReceived() {
+        return eventsReceived;
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.onap.policy.apex.service.engine.event.ApexEventConsumer#getPeeredReference(org.onap.
+     * policy.apex.service.parameters.eventhandler.EventHandlerPeeredMode)
+     */
+    @Override
+    public PeeredReference getPeeredReference(final EventHandlerPeeredMode peeredMode) {
+        return peerReferenceMap.get(peeredMode);
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.onap.policy.apex.service.engine.event.ApexEventConsumer#setPeeredReference(org.onap.
+     * policy.apex.service.parameters.eventhandler.EventHandlerPeeredMode,
+     * org.onap.policy.apex.service.engine.event.PeeredReference)
+     */
+    @Override
+    public void setPeeredReference(final EventHandlerPeeredMode peeredMode, final PeeredReference peeredReference) {
+        peerReferenceMap.put(peeredMode, peeredReference);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see java.lang.Runnable#run()
+     */
+    @Override
+    public void run() {
+        // The endless loop that receives events using REST calls
+        while (consumerThread.isAlive() && !stopOrderedFlag) {
+            try {
+                // Take the next event from the queue
+                final Object eventObject =
+                        incomingEventRequestQueue.poll(EVENT_REQUESTOR_WAIT_SLEEP_TIME, TimeUnit.MILLISECONDS);
+                if (eventObject == null) {
+                    // Poll timed out, wait again
+                    continue;
+                }
+
+                // Send the event into Apex
+                eventReceiver.receiveEvent(eventObject);
+
+                eventsReceived++;
+            } catch (final InterruptedException e) {
+                LOGGER.debug("Thread interrupted, Reason {}", e.getMessage());
+                Thread.currentThread().interrupt();
+            } catch (final Exception e) {
+                LOGGER.warn("error receiving events on thread {}", consumerThread.getName(), e);
+            }
+        }
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.apps.uservice.producer.ApexEventConsumer#stop()
+     */
+    @Override
+    public void stop() {
+        stopOrderedFlag = true;
+
+        while (consumerThread.isAlive()) {
+            ThreadUtilities.sleep(EVENT_REQUESTOR_WAIT_SLEEP_TIME);
+        }
+    }
+}