From eb1a04af65950b86b3e128d1611f218caabf2b17 Mon Sep 17 00:00:00 2001
From: "mergify[bot]" <37929162+mergify[bot]@users.noreply.github.com>
Date: Thu, 3 Jun 2021 05:24:11 +0000
Subject: [PATCH] refactor SnapshotStorage helpers to prepare for later changes
 (#17560) (#17678)

(cherry picked from commit 654918ab27000b71e8af024f374e5d6e3e00cce0)

# Conflicts:
#	runtime/src/accounts_db.rs

Co-authored-by: Jeff Washington (jwash) <75863576+jeffwashington@users.noreply.github.com>
---
 runtime/src/accounts_db.rs | 42 +++++++++++++++++++++++---------------
 1 file changed, 26 insertions(+), 16 deletions(-)

diff --git a/runtime/src/accounts_db.rs b/runtime/src/accounts_db.rs
index 06e4fafc77..5e4344b141 100644
--- a/runtime/src/accounts_db.rs
+++ b/runtime/src/accounts_db.rs
@@ -5599,13 +5599,18 @@ pub mod tests {
         ancestors
     }
 
+    fn empty_storages<'a>() -> &'a [SnapshotStorage] {
+        &[]
+    }
+
     #[test]
     #[should_panic(expected = "assertion failed: bins <= max_plus_1 && bins > 0")]
     fn test_accountsdb_scan_snapshot_stores_illegal_bins2() {
         let mut stats = HashStats::default();
         let bounds = Range { start: 0, end: 0 };
 
-        AccountsDb::scan_snapshot_stores(&[], &mut stats, 257, &bounds, false).unwrap();
+        AccountsDb::scan_snapshot_stores(&empty_storages(), &mut stats, 257, &bounds, false)
+            .unwrap();
     }
     #[test]
     #[should_panic(expected = "assertion failed: bins <= max_plus_1 && bins > 0")]
@@ -5613,7 +5618,7 @@ pub mod tests {
         let mut stats = HashStats::default();
         let bounds = Range { start: 0, end: 0 };
 
-        AccountsDb::scan_snapshot_stores(&[], &mut stats, 0, &bounds, false).unwrap();
+        AccountsDb::scan_snapshot_stores(&empty_storages(), &mut stats, 0, &bounds, false).unwrap();
     }
 
     #[test]
@@ -5624,7 +5629,7 @@ pub mod tests {
         let mut stats = HashStats::default();
         let bounds = Range { start: 2, end: 2 };
 
-        AccountsDb::scan_snapshot_stores(&[], &mut stats, 2, &bounds, false).unwrap();
+        AccountsDb::scan_snapshot_stores(&empty_storages(), &mut stats, 2, &bounds, false).unwrap();
     }
     #[test]
     #[should_panic(
@@ -5634,7 +5639,7 @@ pub mod tests {
         let mut stats = HashStats::default();
         let bounds = Range { start: 1, end: 3 };
 
-        AccountsDb::scan_snapshot_stores(&[], &mut stats, 2, &bounds, false).unwrap();
+        AccountsDb::scan_snapshot_stores(&empty_storages(), &mut stats, 2, &bounds, false).unwrap();
     }
 
     #[test]
@@ -5645,7 +5650,7 @@ pub mod tests {
         let mut stats = HashStats::default();
         let bounds = Range { start: 1, end: 0 };
 
-        AccountsDb::scan_snapshot_stores(&[], &mut stats, 2, &bounds, false).unwrap();
+        AccountsDb::scan_snapshot_stores(&empty_storages(), &mut stats, 2, &bounds, false).unwrap();
     }
 
     fn sample_storages_and_accounts() -> (SnapshotStorages, Vec<CalculateHashIntermediate>) {
@@ -5726,6 +5731,11 @@ pub mod tests {
         (storages, raw_expected)
     }
 
+    fn get_storage_refs(input: &[SnapshotStorage]) -> &[SnapshotStorage] {
+        // these types will be refactored later and this will be a convenient helper function for tests
+        input
+    }
+
     #[test]
     fn test_accountsdb_scan_snapshot_stores() {
         solana_logger::setup();
@@ -5735,7 +5745,7 @@ pub mod tests {
         let mut stats = HashStats::default();
 
         let result = AccountsDb::scan_snapshot_stores(
-            &storages,
+            &get_storage_refs(&storages),
             &mut stats,
             bins,
             &Range {
@@ -5749,7 +5759,7 @@ pub mod tests {
 
         let bins = 2;
         let result = AccountsDb::scan_snapshot_stores(
-            &storages,
+            &get_storage_refs(&storages),
             &mut stats,
             bins,
             &Range {
@@ -5768,7 +5778,7 @@ pub mod tests {
 
         let bins = 4;
         let result = AccountsDb::scan_snapshot_stores(
-            &storages,
+            &get_storage_refs(&storages),
             &mut stats,
             bins,
             &Range {
@@ -5787,7 +5797,7 @@ pub mod tests {
 
         let bins = 256;
         let result = AccountsDb::scan_snapshot_stores(
-            &storages,
+            &get_storage_refs(&storages),
             &mut stats,
             bins,
             &Range {
@@ -5811,7 +5821,7 @@ pub mod tests {
 
         let mut stats = HashStats::default();
         let result = AccountsDb::scan_snapshot_stores(
-            &storages,
+            &get_storage_refs(&storages),
             &mut stats,
             bins,
             &Range {
@@ -5835,7 +5845,7 @@ pub mod tests {
         // just the first bin of 2
         let bins = 2;
         let result = AccountsDb::scan_snapshot_stores(
-            &storages,
+            &get_storage_refs(&storages),
             &mut stats,
             bins,
             &Range {
@@ -5852,7 +5862,7 @@ pub mod tests {
 
         // just the second bin of 2
         let result = AccountsDb::scan_snapshot_stores(
-            &storages,
+            &get_storage_refs(&storages),
             &mut stats,
             bins,
             &Range {
@@ -5872,7 +5882,7 @@ pub mod tests {
         let bins = 4;
         for bin in 0..bins {
             let result = AccountsDb::scan_snapshot_stores(
-                &storages,
+                &get_storage_refs(&storages),
                 &mut stats,
                 bins,
                 &Range {
@@ -5891,7 +5901,7 @@ pub mod tests {
         let bin_locations = vec![0, 127, 128, 255];
         for bin in 0..bins {
             let result = AccountsDb::scan_snapshot_stores(
-                &storages,
+                &get_storage_refs(&storages),
                 &mut stats,
                 bins,
                 &Range {
@@ -5917,7 +5927,7 @@ pub mod tests {
 
         let mut stats = HashStats::default();
         let result = AccountsDb::scan_snapshot_stores(
-            &storages,
+            &get_storage_refs(&storages),
             &mut stats,
             bins,
             &Range {
@@ -6003,7 +6013,7 @@ pub mod tests {
 
         let calls = AtomicU64::new(0);
         let result = AccountsDb::scan_account_storage_no_bank(
-            &storages,
+            &get_storage_refs(&storages),
             |loaded_account: LoadedAccount, accum: &mut Vec<u64>, slot: Slot| {
                 calls.fetch_add(1, Ordering::Relaxed);
                 assert_eq!(loaded_account.pubkey(), &pubkey);