issue-1226: fix entry duplication in TLRUCache (#2803)

ydb-platform · Jan 7, 2025 · d390000 · d390000
1 parent a38b9ab
commit d390000
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Showing 2 changed files with 15 additions and 1 deletion.
diff --git a/cloud/storage/core/libs/common/lru_cache.h b/cloud/storage/core/libs/common/lru_cache.h
@@ -46,7 +46,6 @@ class TLRUCache: public TMapOps<TLRUCache<TKey, TValue>>
         auto it = OrderPositions.find(key);
         if (it != OrderPositions.end()) {
             OrderList.splice(OrderList.begin(), OrderList, it->second);
-            it->second = OrderList.insert(OrderList.begin(), key);
         } else {
             OrderPositions.emplace(
                 key,

diff --git a/cloud/storage/core/libs/common/lru_cache_ut.cpp b/cloud/storage/core/libs/common/lru_cache_ut.cpp
@@ -117,6 +117,21 @@ Y_UNIT_TEST_SUITE(TLRUCache)
 
         UNIT_ASSERT_VALUES_EQUAL(1, hashMap.size());
         UNIT_ASSERT_VALUES_EQUAL("value1", hashMap.find("key1")->second);
+
+        // Test downsizing capacity
+        hashMap.SetCapacity(0);
+        hashMap.SetCapacity(3);
+        hashMap.emplace("key1", "value1");
+        hashMap.emplace("key2", "value2");
+        hashMap.emplace("key3", "value3");
+        hashMap.find("key1");
+        // Now the order is key1, key3, key2
+        hashMap.SetCapacity(2);
+        // Should evict key2
+        UNIT_ASSERT_EQUAL(hashMap.end(), hashMap.find("key2"));
+        UNIT_ASSERT_VALUES_EQUAL("value1", hashMap.find("key1")->second);
+        UNIT_ASSERT_VALUES_EQUAL("value3", hashMap.find("key3")->second);
+        UNIT_ASSERT_VALUES_EQUAL(2, hashMap.size());
     }
 }