Query cache cleaning on node removal if required

Author: alex-kulakov

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

@@ -239,6 +239,12 @@ protected virtual void Cleared() { }
 
     #endregion
 
+    internal IEnumerable<TKey> GetKeysInternal()
+    {
+      foreach (KeyValuePair<TKey, TItem> cachedItem in deque)
+        yield return cachedItem.Key;
+    }
+
 
     // Constructors
 

Orm/Xtensive.Orm/Orm/StorageNodeManager.cs

@@ -5,7 +5,9 @@
 // Created:    2014.03.13
 
 using System;
+using System.Linq;
 using JetBrains.Annotations;
+using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Upgrade;
@@ -34,12 +36,24 @@ public bool AddNode([NotNull] NodeConfiguration configuration)
     /// Removes node with specified <paramref name="nodeId"/>.
     /// </summary>
     /// <param name="nodeId">Node identifier.</param>
+    /// <param name="clearQueryCache">
+    /// if <see langword="true"/> then cached queries dedicated to the removing node will be removed from cache as well. By default <see langword="false"/>.
+    /// </param>
     /// <returns>True if node was removed, otherwise false.</returns>
-    public bool RemoveNode([NotNull] string nodeId)
+    public bool RemoveNode([NotNull] string nodeId, bool clearQueryCache = false)
     {
-      return handlers.StorageNodeRegistry.Remove(nodeId);
+      var removeResult = handlers.StorageNodeRegistry.Remove(nodeId);
+
+      if (removeResult && clearQueryCache) {
+        var queryCache = (Caching.LruCache<object, Pair<object, Linq.TranslatedQuery>>) handlers.Domain.QueryCache;
+        foreach (var key in queryCache.GetKeysInternal().Where(k => k is Pair<object, string> p && p.Second == nodeId).ToChainedBuffer()) {
+          queryCache.RemoveKey(key, true);
+        }
+      }
+      return removeResult;
     }
 
+
     /// <summary>
     /// Gets node with the specified <paramref name="nodeId"/>
     /// </summary>