flush data to the permanent store in larger portions

jormungandr/src/blockchain/storage.rs

@@ -11,6 +11,8 @@ use thiserror::Error;
 use std::convert::identity;
 use std::path::Path;
 
+const PERMANENT_STORE_FLUSH_GAP: u32 = 1024;
+
 #[derive(Debug, Error)]
 pub enum Error {
     #[error("block not found")]
@@ -282,8 +284,13 @@ impl Storage {
         let to_block_info = self
             .storage
             .get_nth_ancestor(main_branch_tip, threshold_depth)?;
-        self.storage
-            .flush_to_permanent_store(to_block_info.id().as_ref())?;
+
+        // Permanent store extension is better to do in large portions of data
+        // at once. This puts less strain on the paging subsystem.
+        if threshold_length % PERMANENT_STORE_FLUSH_GAP == 0 {
+            self.storage
+                .flush_to_permanent_store(to_block_info.id().as_ref())?;
+        }
 
         Ok(())
     }