Incoming events cache - do not load files, which are in progress1.5.2

- Implement singleton cache for events being processed
- Add JUnit tests
- Bump snapshot version 1.5.1 -> 1.5.2

Issue-ID: DCAEGEN2-2659
Signed-off-by: Joanna Jeremicz <joanna.jeremicz@nokia.com>
Change-Id: I79f32554a8c67d91d0d7b601bc8b060ff4984eab

7 files changed, 161 insertions, 4 deletions

diff --git a/Changelog.md b/Changelog.md
index f546520..7114f05 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -4,7 +4,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## [1.5.2] - 16/03/2021    
+
+- Implement singleton cache for events being processed
+- Add JUnit tests
+
 ## [1.5.1] - 03/02/2021      
 
 - Add configuration number of threads and limit rate in files processing
-- Fix vulnerability - update undertow from 2.0.3.Final to 2.2.3.Final and commons.io from 2.6.0 to 2.8.0
\ No newline at end of file
+- Fix vulnerability - update undertow from 2.0.3.Final to 2.2.3.Final and commons.io from 2.6.0 to 2.8.0
diff --git a/pom.xml b/pom.xml
index a594d5d..a6c2187 100644
--- a/pom.xml
+++ b/pom.xml
@@ -33,7 +33,7 @@
 
     <groupId>org.onap.dcaegen2.services</groupId>
     <artifactId>pm-mapper</artifactId>
-    <version>1.5.1-SNAPSHOT</version>
+    <version>1.5.2-SNAPSHOT</version>
 
 
     <name>dcaegen2-services-pm-mapper</name>
diff --git a/src/main/java/org/onap/dcaegen2/services/pmmapper/App.java b/src/main/java/org/onap/dcaegen2/services/pmmapper/App.java
index 4583df3..b020837 100644
--- a/src/main/java/org/onap/dcaegen2/services/pmmapper/App.java
+++ b/src/main/java/org/onap/dcaegen2/services/pmmapper/App.java
@@ -48,6 +48,7 @@ import org.onap.dcaegen2.services.pmmapper.healthcheck.HealthCheckHandler;
 import org.onap.dcaegen2.services.pmmapper.model.ServerResource;
 import org.onap.dcaegen2.services.pmmapper.ssl.SSLContextFactory;
 import org.onap.dcaegen2.services.pmmapper.utils.DataRouterUtils;
+import org.onap.dcaegen2.services.pmmapper.utils.IncomingEventsCache;
 import org.onap.dcaegen2.services.pmmapper.utils.MeasConverter;
 import org.onap.dcaegen2.services.pmmapper.utils.MeasSplitter;
 import org.onap.dcaegen2.services.pmmapper.utils.XMLValidator;
@@ -80,6 +81,7 @@ public class App {
     private static final int HTTPS_PORT = 8443;
     private static final int INITIAL_RECONFIGURATION_PERIOD = 60;
     private static final int RECONFIGURATION_PERIOD = 60;
+    private static final IncomingEventsCache eventsCache = IncomingEventsCache.INSTANCE;
     private static Path templates = Paths.get("/opt/app/pm-mapper/etc/templates/");
     private static Path schemas = Paths.get("/opt/app/pm-mapper/etc/schemas/");
 
@@ -139,6 +141,8 @@ public class App {
 
         this.flux.onBackpressureDrop(App::handleBackPressure)
                 .doOnNext(App::receiveRequest)
+                .filter(event -> !isCached(event.getPublishIdentity()))
+                .doOnNext(App::addToCache)
                 .limitRate(processingConfig.getLimitRate())
                 .parallel(processingThreads)
                 .runOn(Schedulers.newParallel("Thread", processingThreads), PREFETCH_ONE_PER_THREAD)
@@ -204,6 +208,14 @@ public class App {
         }
     }
 
+    private boolean isCached(String id) {
+        boolean isPresent = eventsCache.contains(id);
+        if(isPresent) {
+            logger.unwrap().info("Skipping. This event is already waiting in cache to be processed: " + id);
+        }
+        return isPresent;
+    }
+
     public static void main(String[] args) throws EnvironmentConfigException {
         FilesProcessingConfig processingConfig = new FilesProcessingConfig(new EnvironmentReader());
         new App(templates, schemas, HTTP_PORT, HTTPS_PORT, new ConfigHandler(), processingConfig).start();
@@ -280,6 +292,7 @@ public class App {
     public static void sendEventProcessed(MapperConfig config, Event event) {
       try {
           DataRouterUtils.processEvent(config, event);
+          eventsCache.remove(event.getPublishIdentity());
       } catch (ProcessEventException exception) {
           logger.unwrap().error("Process event failure", exception);
       }
@@ -300,6 +313,14 @@ public class App {
     }
 
     /**
+     * Adds received event to cache
+     * @param event to be cached.
+     */
+    public static void addToCache(@NonNull Event event) {
+        eventsCache.add(event.getPublishIdentity());
+    }
+
+    /**
      * Takes the exchange from an event, responds with a 200 and un-dispatches the exchange.
      * @param event to be received.
      */
diff --git a/src/main/java/org/onap/dcaegen2/services/pmmapper/model/Event.java b/src/main/java/org/onap/dcaegen2/services/pmmapper/model/Event.java
index 57d9570..3bd4a37 100644
--- a/src/main/java/org/onap/dcaegen2/services/pmmapper/model/Event.java
+++ b/src/main/java/org/onap/dcaegen2/services/pmmapper/model/Event.java
@@ -1,6 +1,6 @@
 /*-
  * ============LICENSE_START=======================================================
- *  Copyright (C) 2020 Nordix Foundation.
+ * Copyright (C) 2020 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
diff --git a/src/main/java/org/onap/dcaegen2/services/pmmapper/utils/IncomingEventsCache.java b/src/main/java/org/onap/dcaegen2/services/pmmapper/utils/IncomingEventsCache.java
new file mode 100644
index 0000000..677a3c3
--- /dev/null
+++ b/src/main/java/org/onap/dcaegen2/services/pmmapper/utils/IncomingEventsCache.java
@@ -0,0 +1,68 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 Nokia.
+ * ================================================================================
+ * 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.dcaegen2.services.pmmapper.utils;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+public enum IncomingEventsCache {
+    INSTANCE;
+
+    private Set<String> eventsIds = ConcurrentHashMap.newKeySet();
+
+    /**
+     * Gets thread safe, single instance of this enum
+     * @return the single instance of cache
+     */
+    public IncomingEventsCache getInstance() {
+        return INSTANCE;
+    }
+
+    /**
+     * Adds publishIdentity of an event to cache
+     * @param id to be added to cache
+     */
+    public void add(String id) {
+        eventsIds.add(id);
+    }
+
+    /**
+     * Remove publishIdentity of an event from cache
+     * @param id to be removed from cache
+     */
+    public void remove(String id) {
+        eventsIds.remove(id);
+    }
+
+    /**
+     * Checks if the cache contains a publishIdentity
+     * @param id to be found in cache
+     * @return true when the id exists, false otherwise
+     */
+    public boolean contains(String id) {
+        return eventsIds.contains(id);
+    }
+
+    Set<String> getCachedEvents() {
+        return new HashSet<>(eventsIds);
+    }
+}
diff --git a/src/test/java/org/onap/dcaegen2/services/pmmapper/utils/IncomingEventsCacheTest.java b/src/test/java/org/onap/dcaegen2/services/pmmapper/utils/IncomingEventsCacheTest.java
new file mode 100644
index 0000000..6a77e0f
--- /dev/null
+++ b/src/test/java/org/onap/dcaegen2/services/pmmapper/utils/IncomingEventsCacheTest.java
@@ -0,0 +1,63 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 Nokia.
+ * ================================================================================
+ * 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.dcaegen2.services.pmmapper.utils;
+
+import org.junit.After;
+import org.junit.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class IncomingEventsCacheTest {
+
+    private static final String id1 = "123.dmaap-dr-node";
+    private static final String id2 = "987.dmaap-dr-node";
+
+    @After
+    public void resetCache() {
+        IncomingEventsCache cache = IncomingEventsCache.INSTANCE;
+        for(String id: cache.getCachedEvents()) {
+            cache.remove(id);
+        }
+    }
+
+    @Test
+    public void shouldContainEventAfterAddingItToCache() {
+        IncomingEventsCache eventsCache = IncomingEventsCache.INSTANCE;
+        eventsCache.add(id1);
+        assertEquals(1, IncomingEventsCache.INSTANCE.getCachedEvents().size());
+        assertTrue(IncomingEventsCache.INSTANCE.getCachedEvents().contains(id1));
+    }
+
+    @Test
+    public void shouldRemoveEventFromCache() {
+        IncomingEventsCache eventsCache = IncomingEventsCache.INSTANCE;
+
+        assertEquals(0, IncomingEventsCache.INSTANCE.getCachedEvents().size());
+        eventsCache.add(id1);
+        eventsCache.add(id1);
+        eventsCache.add(id2);
+        assertEquals(2, IncomingEventsCache.INSTANCE.getCachedEvents().size());
+        eventsCache.remove(id1);
+        assertEquals(1, IncomingEventsCache.INSTANCE.getCachedEvents().size());
+        assertTrue(IncomingEventsCache.INSTANCE.getCachedEvents().contains(id2));
+    }
+}
diff --git a/version.properties b/version.properties
index 303a703..3f9d877 100644
--- a/version.properties
+++ b/version.properties
@@ -1,6 +1,6 @@
 major=1
 minor=5
-patch=1
+patch=2
 base_version=${major}.${minor}.${patch}
 release_version=${base_version}
 snapshot_version=${base_version}-SNAPSHOT