1 files changed, 101 insertions, 0 deletions
diff --git a/openecomp-be/api/openecomp-sdc-rest-webapp/item-rest/item-rest-services/src/main/java/org/openecomp/sdcrests/item/rest/services/catalog/notification/AsyncNotifier.java b/openecomp-be/api/openecomp-sdc-rest-webapp/item-rest/item-rest-services/src/main/java/org/openecomp/sdcrests/item/rest/services/catalog/notification/AsyncNotifier.java
new file mode 100644
index 0000000000..82880106d7
--- /dev/null
+++ b/openecomp-be/api/openecomp-sdc-rest-webapp/item-rest/item-rest-services/src/main/java/org/openecomp/sdcrests/item/rest/services/catalog/notification/AsyncNotifier.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright © 2016-2018 European Support Limited
+ *
+ * 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.
+ */
+
+package org.openecomp.sdcrests.item.rest.services.catalog.notification;
+
+import java.util.Collection;
+import java.util.concurrent.Callable;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.function.BiFunction;
+import org.openecomp.sdc.logging.api.Logger;
+import org.openecomp.sdc.logging.api.LoggerFactory;
+import org.openecomp.sdc.logging.api.LoggingContext;
+import org.openecomp.sdcrests.item.types.ItemAction;
+
+/**
+ * Asynchronously runs a notification task.
+ *
+ * @author evitaliy
+ * @since 22 Nov 2018
+ */
+public class AsyncNotifier implements Notifier {
+
+    private static final ScheduledExecutorService EXECUTOR_SERVICE = Executors.newScheduledThreadPool(1);
+
+    private static final int DEFAULT_NUM_OF_RETRIES = 2;
+    private static final long DEFAULT_INTERVAL = 5000;
+
+    private final BiFunction<Collection<String>, ItemAction, Callable<NextAction>> taskProducer;
+
+    AsyncNotifier(BiFunction<Collection<String>, ItemAction, Callable<NextAction>> taskProducer) {
+        this.taskProducer = taskProducer;
+    }
+
+    @Override
+    public void execute(Collection<String> itemIds, ItemAction action) {
+
+        Callable<AsyncNotifier.NextAction> worker = taskProducer.apply(itemIds, action);
+
+        RetryingTask retryingTask =
+                new RetryingTask(worker, DEFAULT_NUM_OF_RETRIES, DEFAULT_INTERVAL, EXECUTOR_SERVICE);
+
+        EXECUTOR_SERVICE.submit(LoggingContext.copyToCallable(retryingTask));
+    }
+
+    public enum NextAction {
+        RETRY, DONE
+    }
+
+    static class RetryingTask implements Callable<Void> {
+
+        private static final Logger LOGGER = LoggerFactory.getLogger(RetryingTask.class);
+
+        private final Callable<AsyncNotifier.NextAction> worker;
+        private final long delay;
+        private final ScheduledExecutorService scheduler;
+        private volatile int retries;
+
+        RetryingTask(Callable<AsyncNotifier.NextAction> worker, int numOfRetries, long delay,
+                ScheduledExecutorService scheduler) {
+
+            this.worker = worker;
+            this.retries = numOfRetries;
+            this.delay = delay;
+            this.scheduler = scheduler;
+        }
+
+        @Override
+        public synchronized Void call() throws Exception {
+
+            NextAction next = worker.call();
+            if (next == NextAction.DONE) {
+                LOGGER.debug("Task successful: {}. Not going to retry", worker);
+                return null;
+            }
+
+            retries--;
+            if (retries == 0) {
+                LOGGER.warn("Exhausted number of retries for task {}, exiting", worker);
+                return null;
+            }
+
+            scheduler.schedule(this, delay, TimeUnit.MILLISECONDS);
+            return null;
+        }
+    }
+}