Improved code coverage (branches) for sync watchdog

- had to refactor prod. code slightly to make it testable
- added a batch size check although the task is a simple iteration there is overhead in creating a paralel task

Issue-ID: CPS-475

Signed-off-by: ToineSiebelink <toine.siebelink@est.tech>
Change-Id: I0db7ba3a15f4edc469a5af1ddc6fd76922b16809

2 files changed, 50 insertions, 13 deletions

diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/sync/ModuleSyncWatchdog.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/sync/ModuleSyncWatchdog.java
index e2330a713..6ff426d66 100644
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/sync/ModuleSyncWatchdog.java
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/sync/ModuleSyncWatchdog.java
@@ -65,16 +65,17 @@ public class ModuleSyncWatchdog {
     public void moduleSyncAdvisedCmHandles() {
         log.info("Processing module sync watchdog waking up.");
         populateWorkQueueIfNeeded();
-        final int asyncTaskParallelismLevel = asyncTaskExecutor.getAsyncTaskParallelismLevel();
         while (!moduleSyncWorkQueue.isEmpty()) {
-            if (batchCounter.get() <= asyncTaskParallelismLevel) {
+            if (batchCounter.get() <= asyncTaskExecutor.getAsyncTaskParallelismLevel()) {
                 final Collection<DataNode> nextBatch = prepareNextBatch();
                 log.info("Processing module sync batch of {}. {} batch(es) active.",
-                        nextBatch.size(), batchCounter.get());
-                asyncTaskExecutor.executeTask(() ->
-                                moduleSyncTasks.performModuleSync(nextBatch, batchCounter),
+                    nextBatch.size(), batchCounter.get());
+                if (!nextBatch.isEmpty()) {
+                    asyncTaskExecutor.executeTask(() ->
+                            moduleSyncTasks.performModuleSync(nextBatch, batchCounter),
                         ASYNC_TASK_TIMEOUT_IN_MILLISECONDS);
-                batchCounter.getAndIncrement();
+                    batchCounter.getAndIncrement();
+                }
             } else {
                 preventBusyWait();
             }
diff --git a/cps-ncmp-service/src/test/groovy/org/onap/cps/ncmp/api/inventory/sync/ModuleSyncWatchdogSpec.groovy b/cps-ncmp-service/src/test/groovy/org/onap/cps/ncmp/api/inventory/sync/ModuleSyncWatchdogSpec.groovy
index a8bbf7c48..bb730fc34 100644
--- a/cps-ncmp-service/src/test/groovy/org/onap/cps/ncmp/api/inventory/sync/ModuleSyncWatchdogSpec.groovy
+++ b/cps-ncmp-service/src/test/groovy/org/onap/cps/ncmp/api/inventory/sync/ModuleSyncWatchdogSpec.groovy
@@ -1,6 +1,6 @@
 /*
  *  ============LICENSE_START=======================================================
- *  Copyright (C) 2022 Nordix Foundation
+ *  Copyright (C) 2022-2023 Nordix Foundation
  *  Modifications Copyright (C) 2022 Bell Canada
  *  ================================================================================
  *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -36,17 +36,16 @@ class ModuleSyncWatchdogSpec extends Specification {
 
     def moduleSyncWorkQueue = new ArrayBlockingQueue(testQueueCapacity)
 
-    def stubModuleSyncStartedOnCmHandles = Stub(IMap<String, Object>)
+    def mockModuleSyncStartedOnCmHandles = Mock(IMap<String, Object>)
 
     def mockModuleSyncTasks = Mock(ModuleSyncTasks)
 
     def spiedAsyncTaskExecutor = Spy(AsyncTaskExecutor)
 
-    def objectUnderTest = new ModuleSyncWatchdog(mockSyncUtils, moduleSyncWorkQueue , stubModuleSyncStartedOnCmHandles,
-            mockModuleSyncTasks, spiedAsyncTaskExecutor)
+    def objectUnderTest = new ModuleSyncWatchdog(mockSyncUtils, moduleSyncWorkQueue , mockModuleSyncStartedOnCmHandles, mockModuleSyncTasks, spiedAsyncTaskExecutor)
 
     void setup() {
-        spiedAsyncTaskExecutor.setupThreadPool();
+        spiedAsyncTaskExecutor.setupThreadPool()
     }
 
     def 'Module sync advised cm handles with #scenario.'() {
@@ -58,7 +57,7 @@ class ModuleSyncWatchdogSpec extends Specification {
             objectUnderTest.moduleSyncAdvisedCmHandles()
         then: 'it performs #expectedNumberOfTaskExecutions tasks'
             expectedNumberOfTaskExecutions * spiedAsyncTaskExecutor.executeTask(*_)
-        where: ' the following parameter are used'
+        where: 'the following parameter are used'
             scenario              | numberOfAdvisedCmHandles                                          || expectedNumberOfTaskExecutions
             'less then 1 batch'   | 1                                                                 || 1
             'exactly 1 batch'     | ModuleSyncWatchdog.MODULE_SYNC_BATCH_SIZE                         || 1
@@ -67,11 +66,48 @@ class ModuleSyncWatchdogSpec extends Specification {
             'over queue capacity' | testQueueCapacity + 2 * ModuleSyncWatchdog.MODULE_SYNC_BATCH_SIZE || 3
     }
 
+    def 'Module sync advised cm handles starts with no available threads.'() {
+        given: 'sync utilities returns a advise cm handles'
+            mockSyncUtils.getAdvisedCmHandles() >> createDataNodes(1)
+        and: 'the executor first has no threads but has one thread on the second attempt'
+            spiedAsyncTaskExecutor.getAsyncTaskParallelismLevel() >>> [ 0, 1 ]
+        when: ' module sync is started'
+            objectUnderTest.moduleSyncAdvisedCmHandles()
+        then: 'it performs one task'
+            1 * spiedAsyncTaskExecutor.executeTask(*_)
+    }
+
+    def 'Module sync advised cm handles already handled.'() {
+        given: 'sync utilities returns a advise cm handles'
+            mockSyncUtils.getAdvisedCmHandles() >> createDataNodes(1)
+        and: 'the executor has a thread available'
+            spiedAsyncTaskExecutor.getAsyncTaskParallelismLevel() >> 1
+        and: 'the semaphore cache indicates the cm handle is already being processed'
+            mockModuleSyncStartedOnCmHandles.putIfAbsent(*_) >> 'Started'
+        when: ' module sync is started'
+            objectUnderTest.moduleSyncAdvisedCmHandles()
+        then: 'it does NOT execute a task to process the (empty) batch'
+            0 * spiedAsyncTaskExecutor.executeTask(*_)
+    }
+
+    def 'Module sync with previous cm handle(s) left in work queue.'() {
+        given: 'there is still a cm handle in the queue'
+            moduleSyncWorkQueue.offer(new DataNode())
+        and: 'sync utilities returns many advise cm handles'
+            mockSyncUtils.getAdvisedCmHandles() >> createDataNodes(500)
+        and: 'the executor has plenty threads available'
+            spiedAsyncTaskExecutor.getAsyncTaskParallelismLevel() >> 10
+        when: ' module sync is started'
+            objectUnderTest.moduleSyncAdvisedCmHandles()
+        then: 'it does executes only one task to process the remaining handle in the queue'
+            1 * spiedAsyncTaskExecutor.executeTask(*_)
+    }
+
     def 'Reset failed cm handles.'() {
         given: 'sync utilities returns failed cm handles'
             def failedCmHandles = [new YangModelCmHandle()]
             mockSyncUtils.getModuleSyncFailedCmHandles() >> failedCmHandles
-        when: ' reset failed cm handles is started'
+        when: 'reset failed cm handles is started'
             objectUnderTest.resetPreviouslyFailedCmHandles()
         then: 'it is delegated to the module sync task (service)'
             1 * mockModuleSyncTasks.resetFailedCmHandles(failedCmHandles)