Add fn to check when to take snapshots (#19682)

core/tests/snapshots.rs

@@ -722,7 +722,8 @@ mod tests {
 
             // Since AccountsBackgroundService isn't running, manually make a full snapshot archive
             // at the right interval
-            if slot % FULL_SNAPSHOT_ARCHIVE_INTERVAL_SLOTS == 0 {
+            if snapshot_utils::should_take_full_snapshot(slot, FULL_SNAPSHOT_ARCHIVE_INTERVAL_SLOTS)
+            {
                 make_full_snapshot_archive(&bank, &snapshot_test_config.snapshot_config).unwrap();
             }
             // Similarly, make an incremental snapshot archive at the right interval, but only if
@@ -730,9 +731,11 @@ mod tests {
             // taken at this slot.
             //
             // Then, after making an incremental snapshot, restore the bank and verify it is correct
-            else if slot % INCREMENTAL_SNAPSHOT_ARCHIVE_INTERVAL_SLOTS == 0
-                && last_full_snapshot_slot.is_some()
-                && slot != last_full_snapshot_slot.unwrap()
+            else if snapshot_utils::should_take_incremental_snapshot(
+                slot,
+                INCREMENTAL_SNAPSHOT_ARCHIVE_INTERVAL_SLOTS,
+                last_full_snapshot_slot,
+            ) && slot != last_full_snapshot_slot.unwrap()
             {
                 make_incremental_snapshot_archive(
                     &bank,

ledger/src/blockstore_processor.rs

@@ -1188,7 +1188,10 @@ fn load_frozen_forks(
 
                 if let Some(snapshot_config) = snapshot_config {
                     let block_height = new_root_bank.block_height();
-                    if block_height % snapshot_config.full_snapshot_archive_interval_slots == 0 {
+                    if snapshot_utils::should_take_full_snapshot(
+                        block_height,
+                        snapshot_config.full_snapshot_archive_interval_slots,
+                    ) {
                         *last_full_snapshot_slot = Some(*root);
                         new_root_bank.clean_accounts(true, true, *last_full_snapshot_slot);
                         snapshot_utils::snapshot_bank(

runtime/src/accounts_background_service.rs

@@ -172,19 +172,18 @@ impl SnapshotRequestHandler {
                 }
 
                 let block_height = snapshot_root_bank.block_height();
-                let snapshot_type = if block_height
-                    % self.snapshot_config.full_snapshot_archive_interval_slots
-                    == 0
-                {
+                let snapshot_type = if snapshot_utils::should_take_full_snapshot(
+                    block_height,
+                    self.snapshot_config.full_snapshot_archive_interval_slots,
+                ) {
                     *last_full_snapshot_slot = Some(snapshot_root_bank.slot());
                     Some(SnapshotType::FullSnapshot)
-                } else if block_height
-                    % self
-                        .snapshot_config
-                        .incremental_snapshot_archive_interval_slots
-                    == 0
-                    && last_full_snapshot_slot.is_some()
-                {
+                } else if snapshot_utils::should_take_incremental_snapshot(
+                    block_height,
+                    self.snapshot_config
+                        .incremental_snapshot_archive_interval_slots,
+                    *last_full_snapshot_slot,
+                ) {
                     Some(SnapshotType::IncrementalSnapshot(
                         last_full_snapshot_slot.unwrap(),
                     ))

runtime/src/snapshot_utils.rs

@@ -1795,6 +1795,22 @@ pub fn package_and_archive_incremental_snapshot(
     ))
 }
 
+pub fn should_take_full_snapshot(
+    block_height: Slot,
+    full_snapshot_archive_interval_slots: Slot,
+) -> bool {
+    block_height % full_snapshot_archive_interval_slots == 0
+}
+
+pub fn should_take_incremental_snapshot(
+    block_height: Slot,
+    incremental_snapshot_archive_interval_slots: Slot,
+    last_full_snapshot_slot: Option<Slot>,
+) -> bool {
+    block_height % incremental_snapshot_archive_interval_slots == 0
+        && last_full_snapshot_slot.is_some()
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;