Declare CacheBase methods as abstract; Change file summary

Author: SergeiPavlov

Orm/Xtensive.Orm.Tests.Core/Caching/LruCacheTest.cs

@@ -1,3 +1,7 @@
+// Copyright (C) 2021 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
+
 using System;
 using System.Threading;
 using System.Threading.Tasks;

Orm/Xtensive.Orm/Caching/CacheBase.cs

@@ -19,15 +19,21 @@ public abstract class CacheBase<TKey, TItem> : ICache<TKey, TItem>
     public virtual TItem this[TKey key, bool markAsHit] => TryGetItem(key, markAsHit, out var item) ? item : default;
 
     /// <inheritdoc/>
-    public virtual int Count => throw new NotImplementedException();
+    public abstract int Count { get; }
 
-    public virtual TItem Add(TItem item, bool replaceIfExists) => throw new NotImplementedException();
+    /// <inheritdoc/>
+    public abstract TItem Add(TItem item, bool replaceIfExists);
 
     /// <inheritdoc/>
     public virtual void Add(TItem item) => Add(item, true);
 
+    /// <inheritdoc/>
     public virtual void Clear() => throw new NotImplementedException();
+
+    /// <inheritdoc/>
     public virtual bool ContainsKey(TKey key) => throw new NotImplementedException();
+
+    /// <inheritdoc/>
     public virtual IEnumerator<TItem> GetEnumerator() => throw new NotImplementedException();
 
     /// <inheritdoc/>
@@ -37,9 +43,14 @@ public virtual void Remove(TItem item)
       RemoveKey(KeyExtractor(item));
     }
 
-    public virtual void RemoveKey(TKey key) => throw new NotImplementedException();
-    public virtual void RemoveKey(TKey key, bool removeCompletely) => throw new NotImplementedException();
-    public virtual bool TryGetItem(TKey key, bool markAsHit, out TItem item) => throw new NotImplementedException();
+    /// <inheritdoc/>
+    public abstract void RemoveKey(TKey key);
+
+    /// <inheritdoc/>
+    public abstract void RemoveKey(TKey key, bool removeCompletely);
+
+    /// <inheritdoc/>
+    public abstract bool TryGetItem(TKey key, bool markAsHit, out TItem item);
   }
 }
 

Orm/Xtensive.Orm/Caching/FastConcurrentLruCache{TKey, TItem}.cs

@@ -1,8 +1,6 @@
-// Copyright (C) 2003-2010 Xtensive LLC.
-// All rights reserved.
-// For conditions of distribution and use, see license.
-// Created by: Alex Ustinov
-// Created:    2007.05.28
+// Copyright (C) 2021 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
 
 using System;
 using System.Collections;