EntitySet.Count returns correct value in Client profile

EntitySetState.TotalItemCount used to be overwritten when prefetch
even if there were some local changes. That caused EntitySet.Count
returning count of only persisted items during Client profile sessions.

Author: alex-kulakov

Orm/Xtensive.Orm.Tests/Storage/NewProfilesTest.cs

@@ -1,4 +1,4 @@
-// Copyright (C) 2014 Xtensive LLC.
+// Copyright (C) 2014 Xtensive LLC.
 // All rights reserved.
 // For conditions of distribution and use, see license.
 // Created by: Alexey Kulakov
@@ -986,5 +986,138 @@ public void ClientProfileRollbackEntitySetsWhenPersistHasFallen()
         Assert.AreEqual(0, session.Query.All<Author>().First(author => author.Name=="Mathew").Books.Count);
       }
     }
+
+    [Test]
+    public void ClientProfileEntitySetCountTest01()
+    {
+      long bookId = 0;
+      using (var session = Domain.OpenSession(serverProfile))
+      using (var transactionScope = session.OpenTransaction()) {
+        var book = new Book() { Title = "First book" };
+
+        var comment1 = new Comment();
+        var comment2 = new Comment();
+
+        book.Comments.Add(comment1);
+        book.Comments.Add(comment2);
+
+        bookId = book.Id;
+        transactionScope.Complete();
+      }
+
+      using (var session = Domain.OpenSession(clientProfile)) {
+        var book = session.Query.All<Book>().FirstOrDefault(b => b.Id == bookId);
+
+        var dummyCount = book.Comments.Count;
+        book.Comments.Add(new Comment());
+
+        Assert.That(book.Comments.Count, Is.EqualTo(3));
+      }
+    }
+
+    [Test]
+    public void ClientProfileEntitySetCount02()
+    {
+      long bookId = 0;
+      using (var session = Domain.OpenSession(serverProfile))
+      using (var transactionScope = session.OpenTransaction()) {
+        var book = new Book() { Title = "First book" };
+
+        var comment1 = new Comment();
+        var comment2 = new Comment();
+
+        book.Comments.Add(comment1);
+        book.Comments.Add(comment2);
+
+        bookId = book.Id;
+        transactionScope.Complete();
+      }
+
+      using (var session = Domain.OpenSession(clientProfile)) {
+        var book = session.Query.All<Book>().FirstOrDefault(b => b.Id == bookId);
+
+        book.Comments.Add(new Comment());
+
+        var enumerableCount = 0;
+        foreach(var comment in book.Comments)
+          enumerableCount++;
+        Assert.That(enumerableCount, Is.EqualTo(3));
+
+        Assert.That(book.Comments.Count, Is.EqualTo(3));
+      }
+    }
+
+    [Test]
+    public void ClientProfileEntitySetCount03()
+    {
+      long bookId = 0;
+      long removingCommentId = 0;
+      using (var session = Domain.OpenSession(serverProfile))
+      using (var transactionScope = session.OpenTransaction()) {
+        var book = new Book() { Title = "First book" };
+
+        var comment1 = new Comment();
+        var comment2 = new Comment();
+        var comment3 = new Comment();
+        var comment4 = new Comment();
+
+        book.Comments.Add(comment1);
+        book.Comments.Add(comment2);
+        book.Comments.Add(comment3);
+        book.Comments.Add(comment4);
+
+        bookId = book.Id;
+        removingCommentId = comment3.Id;
+        transactionScope.Complete();
+      }
+
+      using (var session = Domain.OpenSession(clientProfile)) {
+        var book = session.Query.All<Book>().First(b => b.Id == bookId);
+        var removingComment = session.Query.All<Comment>().First(c => c.Id == removingCommentId);
+
+        var dummyCount = book.Comments.Count;
+        book.Comments.Remove(removingComment);
+
+        Assert.That(book.Comments.Count, Is.EqualTo(3));
+      }
+    }
+
+    [Test]
+    public void ClientProfileEntitySetCount04()
+    {
+      long bookId = 0;
+      long removingCommentId = 0;
+      using (var session = Domain.OpenSession(serverProfile))
+      using (var transactionScope = session.OpenTransaction()) {
+        var book = new Book() { Title = "First book" };
+
+        var comment1 = new Comment();
+        var comment2 = new Comment();
+        var comment3 = new Comment();
+        var comment4 = new Comment();
+
+        book.Comments.Add(comment1);
+        book.Comments.Add(comment2);
+        book.Comments.Add(comment3);
+        book.Comments.Add(comment4);
+
+        bookId = book.Id;
+        removingCommentId = comment3.Id;
+        transactionScope.Complete();
+      }
+
+      using (var session = Domain.OpenSession(clientProfile)) {
+        var book = session.Query.All<Book>().First(b => b.Id == bookId);
+        var removingComment = session.Query.All<Comment>().First(c => c.Id==removingCommentId);
+
+        book.Comments.Remove(removingComment);
+
+        var enumerableCount = 0;
+        foreach (var comment in book.Comments)
+          enumerableCount++;
+        Assert.That(enumerableCount, Is.EqualTo(3));
+        Assert.That(book.Comments.Count, Is.EqualTo(3));
+      }
+    }
   }
 }

Orm/Xtensive.Orm/Orm/Internals/EntitySetState.cs

@@ -38,8 +38,10 @@ public BackupedState(EntitySetState state)
     }
 
     private readonly EntitySetBase owner;
+    private readonly bool isDisconnected;
 
     private bool isLoaded;
+    
     private long? totalItemCount;
     private int version;
     private IDictionary<Key, Key> addedKeys;
@@ -132,11 +134,10 @@ public bool HasChanges
     /// <param name="keys">The keys.</param>
     public void Update(IEnumerable<Key> keys, long? count)
     {
-      FetchedKeys.Clear();
-      TotalItemCount = count;
-      foreach (var key in keys)
-        FetchedKeys.Add(key);
-      Rebind();
+      if (!isDisconnected)
+        UpdateStateRegular(keys, count);
+      else
+        UpdateStateDisconnected(keys, count);
     }
 
     /// <summary>
@@ -321,6 +322,31 @@ IEnumerator IEnumerable.GetEnumerator()
 
     #endregion
 
+
+    private void UpdateStateRegular(IEnumerable<Key> keys, long? count)
+    {
+      FetchedKeys.Clear();
+      TotalItemCount = count;
+      foreach (var key in keys)
+        FetchedKeys.Add(key);
+      Rebind();
+    }
+
+    private void UpdateStateDisconnected(IEnumerable<Key> syncronizedKeys, long? count)
+    {
+      FetchedKeys.Clear();
+      var countExceptRemoved = 0;
+      foreach (var key in syncronizedKeys) {
+        FetchedKeys.Add(key);
+        if (!removedKeys.ContainsKey(key))
+          countExceptRemoved++;
+      }
+      TotalItemCount = count.HasValue
+        ? countExceptRemoved + AddedItemsCount
+        : count;
+      Rebind();
+    }
+
     private void EnsureFetchedKeysIsNotNull()
     {
       if (FetchedKeys==null)
@@ -332,12 +358,6 @@ private void BackupState()
       previousState = new BackupedState(this);
     }
 
-    //private void InitializeFetchedKeysAndClearChanges()
-    //{
-    //  InitializeFetchedKeys();
-    //  InitializeDifferenceCollections();
-    //}
-
     private void InitializeFetchedKeys()
     {
       FetchedKeys = new LruCache<Key, Key>(WellKnown.EntitySetCacheSize, cachedKey => cachedKey);
@@ -358,6 +378,7 @@ internal EntitySetState(EntitySetBase entitySet)
       InitializeDifferenceCollections();
       owner = entitySet;
       version = int.MinValue;
+      isDisconnected = entitySet.Session.IsDisconnected;
     }
   }
 }