[PATCH proxmox-backup v2 1/3] datastore: introduce helper to get store's backend type

[Christian Ebner <c.ebner@proxmox.com>]

In contrast to the pre-existing backend() helper, this newly
introduced backend_type() helper allows to determine a datastores
backend without already instantiating the s3 client in case the
backend is s3.

This will allow to fetch the backend type for the datastore's status
api without having to re-lookup the config.

Signed-off-by: Christian Ebner <c.ebner@proxmox.com>
---
 pbs-datastore/src/datastore.rs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/pbs-datastore/src/datastore.rs b/pbs-datastore/src/datastore.rs
index af883c467..15a34f376 100644
--- a/pbs-datastore/src/datastore.rs
+++ b/pbs-datastore/src/datastore.rs
@@ -403,7 +403,7 @@ impl DataStore {
 
     /// Get the backend for this datastore based on it's configuration
     pub fn backend(&self) -> Result<DatastoreBackend, Error> {
-        let backend_type = match self.inner.backend_config.ty.unwrap_or_default() {
+        let backend = match self.backend_type() {
             DatastoreBackendType::Filesystem => DatastoreBackend::Filesystem,
             DatastoreBackendType::S3 => {
                 let s3_client_id = self
@@ -439,7 +439,11 @@ impl DataStore {
             }
         };
 
-        Ok(backend_type)
+        Ok(backend)
+    }
+
+    pub fn backend_type(&self) -> DatastoreBackendType {
+        self.inner.backend_config.ty.unwrap_or_default()
     }
 
     pub fn cache(&self) -> Option<&LocalDatastoreLruCache> {
-- 
2.47.3