Do not throw exception when no data exist.

The first time we're doing a diff, if a store operation has
never been done before, we shouldn't throw exception, we should
silently succeed and set the diff as empty value.

Change-Id: Ie2371737758a1525da6b76ac85bceb7fe1aa4673
Issue-ID: CCSDK-1690
Signed-off-by: Alexis de Talhouët <adetalhouet89@gmail.com>

2 files changed, 12 insertions, 8 deletions

diff --git a/ms/blueprintsprocessor/functions/config-snapshots/src/main/kotlin/org/onap/ccsdk/cds/blueprintsprocessor/functions/config/snapshots/ComponentConfigSnapshotsExecutor.kt b/ms/blueprintsprocessor/functions/config-snapshots/src/main/kotlin/org/onap/ccsdk/cds/blueprintsprocessor/functions/config/snapshots/ComponentConfigSnapshotsExecutor.kt
index eafcaf44b..180ad7b48 100644
--- a/ms/blueprintsprocessor/functions/config-snapshots/src/main/kotlin/org/onap/ccsdk/cds/blueprintsprocessor/functions/config/snapshots/ComponentConfigSnapshotsExecutor.kt
+++ b/ms/blueprintsprocessor/functions/config-snapshots/src/main/kotlin/org/onap/ccsdk/cds/blueprintsprocessor/functions/config/snapshots/ComponentConfigSnapshotsExecutor.kt
@@ -15,9 +15,10 @@
  *  limitations under the License.
  */
 
-package org.onap.ccsdk.cds.blueprintsprocessor.functions.ansible.executor
+package org.onap.ccsdk.cds.blueprintsprocessor.functions.config.snapshots
 
 import com.github.fge.jsonpatch.diff.JsonDiff
+import org.apache.logging.log4j.util.Strings
 import org.onap.ccsdk.cds.blueprintsprocessor.core.api.data.ExecutionServiceInput
 import org.onap.ccsdk.cds.blueprintsprocessor.functions.config.snapshots.db.ResourceConfigSnapshot
 import org.onap.ccsdk.cds.blueprintsprocessor.functions.config.snapshots.db.ResourceConfigSnapshot.Status.RUNNING
@@ -144,18 +145,20 @@ open class ComponentConfigSnapshotsExecutor(private val cfgSnapshotService: Reso
      */
     private suspend fun compareConfigurationSnapshot(resourceId: String, resourceType: String, contentType : String) {
 
+        val cfgRunning = cfgSnapshotService.findByResourceIdAndResourceTypeAndStatus(resourceId, resourceType, RUNNING)
+        val cfgCandidate = cfgSnapshotService.findByResourceIdAndResourceTypeAndStatus(resourceId, resourceType, CANDIDATE)
+
+        if (cfgRunning.isEmpty() || cfgCandidate.isEmpty()) {
+            setNodeOutputProperties(OUTPUT_STATUS_SUCCESS, Strings.EMPTY)
+            return
+        }
+
         when (contentType.toUpperCase()) {
             DIFF_JSON -> {
-                val cfgRunning = cfgSnapshotService.findByResourceIdAndResourceTypeAndStatus(resourceId, resourceType, RUNNING)
-                val cfgCandidate = cfgSnapshotService.findByResourceIdAndResourceTypeAndStatus(resourceId, resourceType, CANDIDATE)
-
                 val patchNode = JsonDiff.asJson(cfgRunning.jsonAsJsonType(), cfgCandidate.jsonAsJsonType())
                 setNodeOutputProperties(OUTPUT_STATUS_SUCCESS, patchNode.toString())
             }
             DIFF_XML -> {
-                val cfgRunning = cfgSnapshotService.findByResourceIdAndResourceTypeAndStatus(resourceId, resourceType, RUNNING)
-                val cfgCandidate = cfgSnapshotService.findByResourceIdAndResourceTypeAndStatus(resourceId, resourceType, CANDIDATE)
-
                 val myDiff = DiffBuilder
                         .compare(Input.fromString(cfgRunning))
                         .withTest(Input.fromString(cfgCandidate))
diff --git a/ms/blueprintsprocessor/functions/config-snapshots/src/main/kotlin/org/onap/ccsdk/cds/blueprintsprocessor/functions/config/snapshots/db/ResourceConfigSnapshotService.kt b/ms/blueprintsprocessor/functions/config-snapshots/src/main/kotlin/org/onap/ccsdk/cds/blueprintsprocessor/functions/config/snapshots/db/ResourceConfigSnapshotService.kt
index 50c90f332..5fcba5b0c 100644
--- a/ms/blueprintsprocessor/functions/config-snapshots/src/main/kotlin/org/onap/ccsdk/cds/blueprintsprocessor/functions/config/snapshots/db/ResourceConfigSnapshotService.kt
+++ b/ms/blueprintsprocessor/functions/config-snapshots/src/main/kotlin/org/onap/ccsdk/cds/blueprintsprocessor/functions/config/snapshots/db/ResourceConfigSnapshotService.kt
@@ -17,6 +17,7 @@ package org.onap.ccsdk.cds.blueprintsprocessor.functions.config.snapshots.db
 
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
+import org.apache.logging.log4j.util.Strings
 import org.onap.ccsdk.cds.blueprintsprocessor.functions.config.snapshots.db.ResourceConfigSnapshot.Status.RUNNING
 import org.onap.ccsdk.cds.controllerblueprints.core.BluePrintException
 import org.slf4j.LoggerFactory
@@ -40,7 +41,7 @@ class ResourceConfigSnapshotService(private val repository: ResourceConfigSnapsh
                                                          status : ResourceConfigSnapshot.Status = RUNNING): String =
             withContext(Dispatchers.IO) {
                 repository.findByResourceIdAndResourceTypeAndStatus(resourceId, resourceType, status)
-                        ?.config_snapshot ?: throw NoSuchElementException()
+                        ?.config_snapshot ?: Strings.EMPTY
             }
 
     suspend fun write(snapshot: String, resId: String, resType: String,