1 files changed, 68 insertions, 0 deletions
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
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--- /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);
+    }
+}