Don't estimate datastore size when there's only one datastore

CHANGELOG.md

@@ -21,6 +21,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 * GIFs now thumbnail correctly. Thanks @Sorunome!
 * Fixed empty Content-Type header on retrieved remote media. Thanks @silkeh!
 * Fixed various issues with IPv6 handling. Thanks @silkeh!
+* Fixed high database usage for uploads when only one datastore is present.
 
 ## [1.1.3] - July 15th, 2020
 

storage/datastore/datastore.go

@@ -94,7 +94,6 @@ func GetUriForDatastore(dsConf config.DatastoreConfig) string {
 }
 
 func PickDatastore(forKind string, ctx rcontext.RequestContext) (*DatastoreRef, error) {
-	// If we haven't found a legacy option, pick a datastore
 	ctx.Log.Info("Finding a suitable datastore to pick for " + forKind)
 	confDatastores := ctx.Config.DataStores
 	mediaStore := storage.GetDatabase().GetMediaStore(ctx)
@@ -122,9 +121,13 @@ func PickDatastore(forKind string, ctx rcontext.RequestContext) (*DatastoreRef,
 			continue
 		}
 
-		size, err := estimatedDatastoreSize(ds, ctx)
-		if err != nil {
-			continue
+		var size int64
+
+		if len(confDatastores) > 1 {
+			size, err = estimatedDatastoreSize(ds, ctx)
+			if err != nil {
+				continue
+			}
 		}
 
 		if targetDs == nil || size < dsSize {