nicer way of resolve snapshot name

Author: original-brownbear

server/src/main/java/org/elasticsearch/action/admin/cluster/snapshots/create/TransportCreateSnapshotAction.java

@@ -75,23 +75,20 @@ protected void masterOperation(final CreateSnapshotRequest request, ClusterState
                                    final ActionListener<CreateSnapshotResponse> listener) {
         snapshotsService.createSnapshot(request, new SnapshotsService.CreateSnapshotListener() {
             @Override
-            public void onResponse() {
+            public void onResponse(Snapshot snapshotCreated) {
                 if (request.waitForCompletion()) {
-                    final String snapshotName = indexNameExpressionResolver.resolveDateMathExpression(request.snapshot());
                     snapshotsService.addListener(new SnapshotsService.SnapshotCompletionListener() {
                         @Override
                         public void onSnapshotCompletion(Snapshot snapshot, SnapshotInfo snapshotInfo) {
-                            if (snapshot.getRepository().equals(request.repository()) &&
-                                    snapshot.getSnapshotId().getName().equals(snapshotName)) {
+                            if (snapshotCreated.equals(snapshot)) {
                                 listener.onResponse(new CreateSnapshotResponse(snapshotInfo));
                                 snapshotsService.removeListener(this);
                             }
                         }
 
                         @Override
                         public void onSnapshotFailure(Snapshot snapshot, Exception e) {
-                            if (snapshot.getRepository().equals(request.repository()) &&
-                                    snapshot.getSnapshotId().getName().equals(snapshotName)) {
+                            if (snapshotCreated.equals(snapshot)) {
                                 listener.onFailure(e);
                                 snapshotsService.removeListener(this);
                             }

server/src/main/java/org/elasticsearch/snapshots/SnapshotsService.java

@@ -377,7 +377,7 @@ protected void doRun() {
                 logger.info("snapshot [{}] started", snapshot.snapshot());
                 if (snapshot.indices().isEmpty()) {
                     // No indices in this snapshot - we are done
-                    userCreateSnapshotListener.onResponse();
+                    userCreateSnapshotListener.onResponse(snapshot.snapshot());
                     endSnapshot(snapshot);
                     return;
                 }
@@ -465,7 +465,7 @@ public void clusterStateProcessed(String source, ClusterState oldState, ClusterS
                         // for processing. If client wants to wait for the snapshot completion, it can register snapshot
                         // completion listener in this method. For the snapshot completion to work properly, the snapshot
                         // should still exist when listener is registered.
-                        userCreateSnapshotListener.onResponse();
+                        userCreateSnapshotListener.onResponse(snapshot.snapshot());
 
                         // Now that snapshot completion listener is registered we can end the snapshot if needed
                         // We should end snapshot only if 1) we didn't accept it for processing (which happens when there
@@ -1544,8 +1544,10 @@ public interface CreateSnapshotListener {
 
         /**
          * Called when snapshot has successfully started
+         *
+         * @param snapshot snapshot that was created
          */
-        void onResponse();
+        void onResponse(Snapshot snapshot);
 
         /**
          * Called if a snapshot operation couldn't start