cr fixes

Author: kungasc

ydb/core/tablet_flat/shared_cache_switchable.h

@@ -81,6 +81,7 @@ class TSwitchableCache : public ICacheCache<TPage> {
 
     public:
         const ui32 Id; // in [1 .. MaxCachesCount] range
+
     private:
         const THolder<ICacheCache<TPage>> Cache;
         const TCounterPtr SizeCounter;
@@ -129,12 +130,18 @@ class TSwitchableCache : public ICacheCache<TPage> {
             return Caches.back().Touch(page);
         }
 
-        TIntrusiveList<TPage> evictedList = GetCache(TPageTraits::GetCacheId(page)).Touch(page);
+        ui32 cacheId = TPageTraits::GetCacheId(page);
+        if (cacheId > 0 && cacheId != Caches.back().Id) {
+            // rotate the current page first:
+            GetCache(cacheId).Erase(page);
+        }
+        
+        TIntrusiveList<TPage> evictedList = Caches.back().Touch(page);
 
         RotatePages(evictedList);
 
         while (GetSize() > Limit && Caches.size() > 1) {
-            Append(evictedList, EvictNext());
+            evictedList.Append(EvictNext());
         }
 
         return evictedList;
@@ -210,21 +217,14 @@ class TSwitchableCache : public ICacheCache<TPage> {
 
                 // touch each page multiple times to make it warm
                 for (ui32 touchTimes = 0; touchTimes < 3; touchTimes++) {
-                    Append(evictedList, Caches.back().Touch(page));
+                    evictedList.Append(Caches.back().Touch(page));
                 }
 
                 rotatedPagesCount++;
             }
         }
     }
 
-    void Append(TIntrusiveList<TPage>& left, TIntrusiveList<TPage>&& right) {
-        while (!right.Empty()) {
-            TPage* page = right.PopFront();
-            left.PushBack(page);
-        }
-    }
-
 private:
     ui64 Limit;
     TDeque<TCacheHolder> Caches;

ydb/core/tablet_flat/shared_cache_switchable_ut.cpp

@@ -431,13 +431,13 @@ Y_UNIT_TEST_SUITE(TSwitchableCache) {
 
         Touch(cache, *pages[23]);
         UNIT_ASSERT_VALUES_EQUAL(cache.GetSize(), 50);
-        UNIT_ASSERT_VALUES_EQUAL(counter1->Val(), 29);
-        UNIT_ASSERT_VALUES_EQUAL(counter2->Val(), 21);
+        UNIT_ASSERT_VALUES_EQUAL(counter1->Val(), 28);
+        UNIT_ASSERT_VALUES_EQUAL(counter2->Val(), 22);
 
         Touch(cache, *pages[7]);
         UNIT_ASSERT_VALUES_EQUAL(cache.GetSize(), 50);
-        UNIT_ASSERT_VALUES_EQUAL(counter1->Val(), 19);
-        UNIT_ASSERT_VALUES_EQUAL(counter2->Val(), 31);
+        UNIT_ASSERT_VALUES_EQUAL(counter1->Val(), 18);
+        UNIT_ASSERT_VALUES_EQUAL(counter2->Val(), 32);
     }
 
     Y_UNIT_TEST(Switch_Erase) {
@@ -527,8 +527,8 @@ Y_UNIT_TEST_SUITE(TSwitchableCache) {
         cache.UpdateLimit(40);
         UNIT_ASSERT_VALUES_EQUAL(Touch(cache, *pages[23]), (TVector<ui32>{21, 22, 24, 25, 26, 27, 28, 29, 30, 31}));
         UNIT_ASSERT_VALUES_EQUAL(cache.GetSize(), 40);
-        UNIT_ASSERT_VALUES_EQUAL(counter1->Val(), 19); // [32 .. 39, 23]
-        UNIT_ASSERT_VALUES_EQUAL(counter2->Val(), 21); // [50, 0 .. 20]
+        UNIT_ASSERT_VALUES_EQUAL(counter1->Val(), 18); // [32 .. 49]
+        UNIT_ASSERT_VALUES_EQUAL(counter2->Val(), 22); // [50, 0 .. 9, 23, 11 .. 20]
 
         cache.UpdateLimit(7);
         UNIT_ASSERT_VALUES_EQUAL(Touch(cache, *pages[7]).size(), 33);