Optimize and refactor EventPublisher class in VES

* Remove need for having sendEvent synchronized by means of using
  Guava LoadingCache. The only thing that made it synchronized was the
  creation of new entries in the map but the synchronization was made
  on each incoming event.
* Split the class to smaller classes which conform to SRP. This makes us
  able to...
* ... write unit tests for affected classes
* TODO: upgrade to Java8 so lambdas will simplify the code even more

Change-Id: I14cf4cfab0570ce5aecc9a5e5dc9f541c499f9d7
Issue-ID: DCAEGEN2-440
Signed-off-by: Piotr Jaszczyk <piotr.jaszczyk@nokia.com>

3 files changed, 229 insertions, 149 deletions

diff --git a/src/main/java/org/onap/dcae/commonFunction/CambriaPublisherFactory.java b/src/main/java/org/onap/dcae/commonFunction/CambriaPublisherFactory.java
new file mode 100644
index 00000000..35d3e317
--- /dev/null
+++ b/src/main/java/org/onap/dcae/commonFunction/CambriaPublisherFactory.java
@@ -0,0 +1,69 @@
+package org.onap.dcae.commonFunction;
+/*-
+ * ============LICENSE_START=======================================================
+ * org.onap.dcaegen2.collectors.ves
+ * ================================================================================
+ * Copyright (C) 2017-2018 AT&T Intellectual Property. All rights reserved.
+ * Copyright (C) 2018 Nokia. 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=========================================================
+ */
+import com.att.nsa.cambria.client.CambriaBatchingPublisher;
+import com.att.nsa.cambria.client.CambriaClientBuilders;
+import java.net.MalformedURLException;
+import java.security.GeneralSecurityException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+class CambriaPublisherFactory {
+
+    private static Logger log = LoggerFactory.getLogger(CambriaPublisherFactory.class);
+
+    public CambriaBatchingPublisher createCambriaPublisher(String streamId)
+            throws MalformedURLException, GeneralSecurityException {
+        String authpwd = null;
+        String ueburl = DmaapPropertyReader.getInstance(CommonStartup.cambriaConfigFile).dmaap_hash
+                .get(streamId + ".cambria.url");
+
+        if (ueburl == null) {
+            ueburl = DmaapPropertyReader.getInstance(CommonStartup.cambriaConfigFile).dmaap_hash
+                    .get(streamId + ".cambria.hosts");
+        }
+        String topic = DmaapPropertyReader.getInstance(CommonStartup.cambriaConfigFile)
+                .getKeyValue(streamId + ".cambria.topic");
+        String authuser = DmaapPropertyReader.getInstance(CommonStartup.cambriaConfigFile)
+                .getKeyValue(streamId + ".basicAuthUsername");
+
+        if (authuser != null) {
+            authpwd = DmaapPropertyReader.getInstance(CommonStartup.cambriaConfigFile).dmaap_hash
+                    .get(streamId + ".basicAuthPassword");
+        }
+
+        if ((authuser != null) && (authpwd != null)) {
+            log.debug(String.format("URL:%sTOPIC:%sAuthUser:%sAuthpwd:%s", ueburl, topic, authuser, authpwd));
+            return new CambriaClientBuilders.PublisherBuilder().usingHosts(ueburl).onTopic(topic).usingHttps()
+                    .authenticatedByHttp(authuser, authpwd).logSendFailuresAfter(5)
+                    // .logTo(log)
+                    // .limitBatch(100, 10)
+                    .build();
+        } else {
+            log.debug(String.format("URL:%sTOPIC:%s", ueburl, topic));
+            return new CambriaClientBuilders.PublisherBuilder().usingHosts(ueburl).onTopic(topic)
+                    // .logTo(log)
+                    .logSendFailuresAfter(5)
+                    // .limitBatch(100, 10)
+                    .build();
+        }
+    }
+}
diff --git a/src/main/java/org/onap/dcae/commonFunction/DmaapPublishers.java b/src/main/java/org/onap/dcae/commonFunction/DmaapPublishers.java
new file mode 100644
index 00000000..c86a3742
--- /dev/null
+++ b/src/main/java/org/onap/dcae/commonFunction/DmaapPublishers.java
@@ -0,0 +1,96 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * org.onap.dcaegen2.collectors.ves
+ * ================================================================================
+ * Copyright (C) 2017-2018 AT&T Intellectual Property. All rights reserved.
+ * Copyright (C) 2018 Nokia. 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.dcae.commonFunction;
+
+import com.att.nsa.cambria.client.CambriaBatchingPublisher;
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
+import com.google.common.cache.RemovalListener;
+import com.google.common.cache.RemovalNotification;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.security.GeneralSecurityException;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+class DmaapPublishers {
+
+    private static Logger log = LoggerFactory.getLogger(DmaapPublishers.class);
+    private final LoadingCache<String, CambriaBatchingPublisher> publishers;
+
+    private DmaapPublishers(
+            LoadingCache<String, CambriaBatchingPublisher> publishers) {
+        this.publishers = publishers;
+    }
+
+    static DmaapPublishers create() {
+        return create(new CambriaPublisherFactory());
+    }
+
+    static DmaapPublishers create(final CambriaPublisherFactory publisherFactory) {
+        final LoadingCache<String, CambriaBatchingPublisher> cache = CacheBuilder.<String, CambriaBatchingPublisher>newBuilder()
+//            .expireAfterAccess(10, TimeUnit.MINUTES)
+                .removalListener(new RemovalListener<String, CambriaBatchingPublisher>() {
+                    @Override
+                    public void onRemoval(RemovalNotification<String, CambriaBatchingPublisher> notification) {
+                        if (notification.getValue() != null) {
+                            onCacheItemInvalidated(notification.getValue());
+                        }
+                    }
+                })
+                .build(new CacheLoader<String, CambriaBatchingPublisher>() {
+                    @Override
+                    public CambriaBatchingPublisher load(String streamId)
+                            throws MalformedURLException, GeneralSecurityException {
+                        try {
+                            return publisherFactory.createCambriaPublisher(streamId);
+                        } catch (MalformedURLException | GeneralSecurityException e) {
+                            log.error("CambriaClientBuilders connection reader exception : streamID - " + streamId + " "
+                                    + e.getMessage());
+                            throw e;
+                        }
+                    }
+                });
+        return new DmaapPublishers(cache);
+    }
+
+    public CambriaBatchingPublisher getByStreamId(String streamId) {
+        return publishers.getUnchecked(streamId);
+    }
+
+    public void closeByStreamId(String streamId) {
+        publishers.invalidate(streamId);
+    }
+
+    private static void onCacheItemInvalidated(CambriaBatchingPublisher pub) {
+        try {
+            final List<?> stuck = pub.close(20, TimeUnit.SECONDS);
+            if (!stuck.isEmpty()) {
+                log.error(stuck.size() + " messages unsent");
+            }
+        } catch (InterruptedException | IOException e) {
+            log.error("Caught Exception on Close event: {}", e);
+        }
+    }
+}
diff --git a/src/main/java/org/onap/dcae/commonFunction/EventPublisherHash.java b/src/main/java/org/onap/dcae/commonFunction/EventPublisherHash.java
index 49221418..474424a7 100644
--- a/src/main/java/org/onap/dcae/commonFunction/EventPublisherHash.java
+++ b/src/main/java/org/onap/dcae/commonFunction/EventPublisherHash.java
@@ -1,15 +1,16 @@
 /*-
  * ============LICENSE_START=======================================================
- * PROJECT
+ * org.onap.dcaegen2.collectors.ves
  * ================================================================================
  * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
+ * Copyright (C) 2018 Nokia. 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.
@@ -21,159 +22,73 @@
 package org.onap.dcae.commonFunction;
 
 import com.att.nsa.cambria.client.CambriaBatchingPublisher;
-import com.att.nsa.cambria.client.CambriaClientBuilders;
 import com.att.nsa.clock.SaClock;
 import com.att.nsa.logging.LoggingContext;
 import com.att.nsa.logging.log4j.EcompFields;
-import com.google.gson.JsonArray;
-
+import com.google.common.annotations.VisibleForTesting;
+import java.io.IOException;
 import org.json.JSONObject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.IOException;
-import java.security.GeneralSecurityException;
-import java.util.HashMap;
-import java.util.List;
-import java.util.concurrent.TimeUnit;
-
 public class EventPublisherHash {
 
-	private static final String VES_UNIQUE_ID = "VESuniqueId";
-	private static EventPublisherHash instance;
-	private  CambriaBatchingPublisher pub;
-
-	private String streamid = "";
-	private String ueburl = "";
-	private String topic = "";
-	private String authuser = "";
-	private String authpwd = "";
-
-	private static Logger log = LoggerFactory.getLogger(EventPublisherHash.class);
-
-	protected static HashMap<String, CambriaBatchingPublisher> map = new HashMap<String, CambriaBatchingPublisher>();
-	
-
-
-	public CambriaBatchingPublisher Dmaaphash(String newstreamid) {
-		pub = null;
-		streamid = newstreamid;
-		if (map != null && map.containsKey(streamid)){
-			pub =  map.get(streamid);
-			
-		}
-		else
-		{
-		
-		try {
-			ueburl = DmaapPropertyReader.getInstance(CommonStartup.cambriaConfigFile).dmaap_hash
-					.get(streamid + ".cambria.url");
-
-			if (ueburl == null) {
-				ueburl = DmaapPropertyReader.getInstance(CommonStartup.cambriaConfigFile).dmaap_hash
-						.get(streamid + ".cambria.hosts");
-			}
-			topic = DmaapPropertyReader.getInstance(CommonStartup.cambriaConfigFile)
-					.getKeyValue(streamid + ".cambria.topic");
-			authuser = DmaapPropertyReader.getInstance(CommonStartup.cambriaConfigFile)
-					.getKeyValue(streamid + ".basicAuthUsername");
-
-			if (authuser != null) {
-				authpwd = DmaapPropertyReader.getInstance(CommonStartup.cambriaConfigFile).dmaap_hash
-						.get(streamid + ".basicAuthPassword");
-			}
-			
-			
-			if ((authuser != null)  &&  (authpwd != null)) {
-				log.debug(String.format("URL:%sTOPIC:%sAuthUser:%sAuthpwd:%s", ueburl, topic, authuser, authpwd));
-				pub = new CambriaClientBuilders.PublisherBuilder().usingHosts(ueburl).onTopic(topic).usingHttps()
-						.authenticatedByHttp(authuser, authpwd).logSendFailuresAfter(5)
-						// .logTo(log)
-						// .limitBatch(100, 10)
-						.build();
-			} else {
-
-				log.debug(String.format("URL:%sTOPIC:%s", ueburl, topic));
-				pub = new CambriaClientBuilders.PublisherBuilder().usingHosts(ueburl).onTopic(topic)
-						// .logTo(log)
-						.logSendFailuresAfter(5)
-						// .limitBatch(100, 10)
-						.build();
-
-			}
-			
-			map.put(streamid, pub);
-			
-
-		}  catch ( Exception e) {
-			log.error("CambriaClientBuilders connection reader exception : streamID - " + newstreamid + " " + e.getMessage());
-		} 
-
-		}
-		return pub;
-	
-	}
-
-	/**
-	 * Returns event publisher
-	 * @return event publisher
-	 */
-	public static synchronized EventPublisherHash getInstance() {
-		if (instance == null) {
-			instance = new EventPublisherHash();
-		}
-		return instance;
-
-	}
-
-
-	public synchronized void sendEvent(JSONObject event, String streamid) {
-
-		log.debug("EventPublisher.sendEvent: instance for publish is ready");
-
-		if (event.has(VES_UNIQUE_ID)) {
-			String uuid = event.get(VES_UNIQUE_ID).toString();
-			LoggingContext localLC = VESLogger.getLoggingContextForThread(uuid);
-			localLC.put(EcompFields.kBeginTimestampMs, SaClock.now());
-			log.debug("Removing VESuniqueid object from event");
-			event.remove(VES_UNIQUE_ID);
-		}
-
-		try {
-			
-			
-			int pendingMsgs = Dmaaphash(streamid).send("MyPartitionKey", event.toString());
-			// this.wait(2000);
-
-			if (pendingMsgs > 100) {
-				log.info("Pending Message Count=" + pendingMsgs);
-			}
-
-			log.info("pub.send invoked - no error");
-			//CommonStartup.oplog.info(String.format("URL:%sTOPIC:%sEvent Published:%s", ueburl, topic, event));
-			CommonStartup.oplog.info(String.format("StreamID:%s Event Published:%s ", streamid, event));
-		} catch (IOException  | IllegalArgumentException e) {
-			log.error("Unable to publish event: {} streamid: {}. Exception: {}", event, streamid, e);
-			Dmaaphash(streamid).close();
-			map.remove(streamid);
-		} 
-
-	}
-
-	public synchronized void closePublisher() {
-
-		try {
-			if (pub != null) {
-				
-				final List<?> stuck = pub.close(20, TimeUnit.SECONDS);
-				if (!stuck.isEmpty()) {
-					log.error(stuck.size() + " messages unsent");
-				}
-			}
-		} catch (InterruptedException | IOException e) {
-			log.error("Caught Exception on Close event: {}", e);
-		}
-
-	}
+    private static final String VES_UNIQUE_ID = "VESuniqueId";
+    private static final Logger log = LoggerFactory.getLogger(EventPublisherHash.class);
+    private static volatile EventPublisherHash instance = new EventPublisherHash(DmaapPublishers.create());
+    private final DmaapPublishers dmaapPublishers;
+
+    /**
+     * Returns event publisher
+     *
+     * @return event publisher
+     */
+    public static EventPublisherHash getInstance() {
+        return instance;
+    }
+
+    @VisibleForTesting
+    EventPublisherHash(DmaapPublishers dmaapPublishers) {
+        this.dmaapPublishers = dmaapPublishers;
+    }
+
+    public void sendEvent(JSONObject event, String streamid) {
+        log.debug("EventPublisher.sendEvent: instance for publish is ready");
+        clearVesUniqueId(event);
+
+        try {
+            sendEventUsingCachedPublisher(streamid, event);
+        } catch (IOException | IllegalArgumentException e) {
+            log.error("Unable to publish event: {} streamid: {}. Exception: {}", event, streamid, e);
+            dmaapPublishers.closeByStreamId(streamid);
+        }
+    }
+
+    private void clearVesUniqueId(JSONObject event) {
+        if (event.has(VES_UNIQUE_ID)) {
+            String uuid = event.get(VES_UNIQUE_ID).toString();
+            LoggingContext localLC = VESLogger.getLoggingContextForThread(uuid);
+            localLC.put(EcompFields.kBeginTimestampMs, SaClock.now());
+            log.debug("Removing VESuniqueid object from event");
+            event.remove(VES_UNIQUE_ID);
+        }
+    }
+
+    private void sendEventUsingCachedPublisher(String streamid, JSONObject event) throws IOException {
+        int pendingMsgs = dmaapPublishers.getByStreamId(streamid).send("MyPartitionKey", event.toString());
+        // this.wait(2000);
+
+        if (pendingMsgs > 100) {
+            log.info("Pending Message Count=" + pendingMsgs);
+        }
+
+        log.info("pub.send invoked - no error");
+        //CommonStartup.oplog.info(String.format("URL:%sTOPIC:%sEvent Published:%s", ueburl, topic, event));
+        CommonStartup.oplog.info(String.format("StreamID:%s Event Published:%s ", streamid, event));
+    }
+
+    @VisibleForTesting
+    public CambriaBatchingPublisher getDmaapPublisher(String streamId) {
+        return dmaapPublishers.getByStreamId(streamId);
+    }
 }
-