src/backup/prune.rs: add new helper keeps_something()

src/api2/admin/datastore.rs

@@ -294,26 +294,6 @@ fn prune(
 
     let datastore = DataStore::lookup_datastore(store)?;
 
-    let mut keep_all = true;
-
-    for opt in &["keep-last", "keep-daily", "keep-weekly", "keep-weekly", "keep-yearly"] {
-        if !param[opt].is_null() {
-            keep_all = false;
-            break;
-        }
-    }
-
-    let worker = WorkerTask::new("prune", Some(store.to_owned()), "root@pam", true)?;
-    let result = try_block! {
-        if keep_all {
-            worker.log("No prune selection - keeping all files.");
-            return Ok(());
-        } else {
-            worker.log(format!("Starting prune on store {}", store));
-        }
-
-        let list = group.list_backups(&datastore.base_path())?;
-
     let prune_options = PruneOptions {
         keep_last: param["keep-last"].as_u64(),
         keep_daily: param["keep-daily"].as_u64(),
@@ -322,6 +302,17 @@ fn prune(
         keep_yearly: param["keep-yearly"].as_u64(),
     };
 
+    let worker = WorkerTask::new("prune", Some(store.to_owned()), "root@pam", true)?;
+    let result = try_block! {
+        if !prune_options.keeps_something() {
+            worker.log("No prune selection - keeping all files.");
+            return Ok(());
+        } else {
+            worker.log(format!("Starting prune on store {}", store));
+        }
+
+        let list = group.list_backups(&datastore.base_path())?;
+
         let mut prune_info = compute_prune_info(list, &prune_options)?;
 
         prune_info.reverse(); // delete older snapshots first

src/backup/prune.rs

@@ -113,6 +113,16 @@ impl PruneOptions {
         self.keep_yearly = value;
         self
     }
+
+    pub fn keeps_something(&self) -> bool {
+        let mut keep_something = false;
+        if let Some(count) = self.keep_last { if count > 0 { keep_something = true; } }
+        if let Some(count) = self.keep_daily { if count > 0 { keep_something = true; } }
+        if let Some(count) = self.keep_weekly { if count > 0 { keep_something = true; } }
+        if let Some(count) = self.keep_monthly { if count > 0 { keep_something = true; } }
+        if let Some(count) = self.keep_yearly { if count > 0 { keep_something = true; } }
+        keep_something
+    }
 }
 
 pub fn compute_prune_info(