[Nhibernate-commit] SF.net SVN: nhibernate:[4984] trunk/nhibernate/src/NHibernate

[<ste...@us...>]

Revision: 4984
          http://nhibernate.svn.sourceforge.net/nhibernate/?rev=4984&view=rev
Author:   steverstrong
Date:     2010-05-27 14:18:07 +0000 (Thu, 27 May 2010)

Log Message:
-----------
Added support for queries such as "from c in db.Customers.Cacheable() select c"

Modified Paths:
--------------
    trunk/nhibernate/src/NHibernate/Linq/ReWriters/QueryReferenceExpressionFlattener.cs
    trunk/nhibernate/src/NHibernate.Test/Linq/QueryCacheableTests.cs

Modified: trunk/nhibernate/src/NHibernate/Linq/ReWriters/QueryReferenceExpressionFlattener.cs
===================================================================
--- trunk/nhibernate/src/NHibernate/Linq/ReWriters/QueryReferenceExpressionFlattener.cs	2010-05-27 10:11:44 UTC (rev 4983)
+++ trunk/nhibernate/src/NHibernate/Linq/ReWriters/QueryReferenceExpressionFlattener.cs	2010-05-27 14:18:07 UTC (rev 4984)
@@ -8,17 +8,43 @@
 {
 	public class QueryReferenceExpressionFlattener : NhExpressionTreeVisitor
 	{
-		private QueryReferenceExpressionFlattener()
+	    private readonly QueryModel _model;
+
+	    private QueryReferenceExpressionFlattener(QueryModel model)
 		{
+		    _model = model;
 		}
 
-		public static void ReWrite(QueryModel model)
+	    public static void ReWrite(QueryModel model)
 		{
-			var visitor = new QueryReferenceExpressionFlattener();
+			var visitor = new QueryReferenceExpressionFlattener(model);
 			model.TransformExpressions(visitor.VisitExpression);
 		}
 
-		protected override Expression VisitQuerySourceReferenceExpression(QuerySourceReferenceExpression expression)
+        protected override Expression VisitSubQueryExpression(SubQueryExpression subQuery)
+        {
+            if ((subQuery.QueryModel.BodyClauses.Count == 0) &&
+                ((subQuery.QueryModel.ResultOperators.Count == 0) || (subQuery.QueryModel.ResultOperators.Count == 1 && subQuery.QueryModel.ResultOperators[0] is CacheableResultOperator))
+                )
+            {
+                var selectQuerySource =
+                    subQuery.QueryModel.SelectClause.Selector as QuerySourceReferenceExpression;
+
+                if (selectQuerySource != null && selectQuerySource.ReferencedQuerySource == subQuery.QueryModel.MainFromClause)
+                {
+                    if (subQuery.QueryModel.ResultOperators.Count == 1)
+                    {
+                        _model.ResultOperators.Add(subQuery.QueryModel.ResultOperators[0]);
+                    }
+
+                    return subQuery.QueryModel.MainFromClause.FromExpression;
+                }
+            }
+
+            return base.VisitSubQueryExpression(subQuery);
+        }
+
+        protected override Expression VisitQuerySourceReferenceExpression(QuerySourceReferenceExpression expression)
 		{
 			var fromClauseBase = expression.ReferencedQuerySource as FromClauseBase;
 
@@ -28,10 +54,8 @@
 			{
 				return fromClauseBase.FromExpression;
 			}
-			else
-			{
-				return base.VisitQuerySourceReferenceExpression(expression);
-			}
+
+		    return base.VisitQuerySourceReferenceExpression(expression);
 		}
 	}
 }
\ No newline at end of file

Modified: trunk/nhibernate/src/NHibernate.Test/Linq/QueryCacheableTests.cs
===================================================================
--- trunk/nhibernate/src/NHibernate.Test/Linq/QueryCacheableTests.cs	2010-05-27 10:11:44 UTC (rev 4983)
+++ trunk/nhibernate/src/NHibernate.Test/Linq/QueryCacheableTests.cs	2010-05-27 14:18:07 UTC (rev 4984)
@@ -50,6 +50,23 @@
         }
 
         [Test]
+        public void QueryIsCacheable3()
+        {
+            Sfi.Statistics.Clear();
+            Sfi.QueryCache.Clear();
+
+            var x = (from c in db.Customers.Cacheable()
+                     select c).ToList();
+
+            var x2 = (from c in db.Customers
+                      select c).ToList();
+
+            Assert.That(Sfi.Statistics.QueryExecutionCount, Is.EqualTo(2));
+            Assert.That(Sfi.Statistics.QueryCachePutCount, Is.EqualTo(1));
+            Assert.That(Sfi.Statistics.QueryCacheHitCount, Is.EqualTo(0));
+        }
+
+        [Test]
         public void QueryIsCacheableWithRegion()
         {
             Sfi.Statistics.Clear();


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