NH-2319 - Add ability to query collections with AsQueryable()

doc/reference/modules/query_linq.xml

@@ -54,6 +54,14 @@ using NHibernate.Linq;]]></programlisting>
       This will be executed as a query on that <literal>cat</literal>'s kittens without loading the
       entire collection.
     </para>
+    <para>
+      If the collection is a map, call <literal>AsQueryable</literal> on its <literal>Values</literal>
+      property.
+    </para>
+    <programlisting><![CDATA[IList<Cat> whiteKittens =
+    cat.Kittens.Values.AsQueryable()
+        .Where(k => k.Color == "white")
+        .ToList();]]></programlisting>
     <para>&nbsp;</para>
 
     <para>

src/NHibernate.Test/Async/NHSpecificTest/NH1612/NativeSqlCollectionLoaderFixture.cs

@@ -51,8 +51,8 @@ public async Task LoadCompositeElementsWithWithSimpleHbmAliasInjectionAsync()
 			Country country = await (LoadCountryWithNativeSQLAsync(CreateCountry(stats), "LoadAreaStatisticsWithSimpleHbmAliasInjection"));
 
 			Assert.That(country, Is.Not.Null);
-			Assert.That((ICollection) country.Statistics.Keys, Is.EquivalentTo((ICollection) stats.Keys), "Keys");
-			Assert.That((ICollection) country.Statistics.Values, Is.EquivalentTo((ICollection) stats.Values), "Elements");
+			Assert.That(country.Statistics.Keys, Is.EquivalentTo(stats.Keys), "Keys");
+			Assert.That(country.Statistics.Values, Is.EquivalentTo(stats.Values), "Elements");
 			await (CleanupWithPersonsAsync());
 		}
 
@@ -63,8 +63,8 @@ public async Task LoadCompositeElementsWithWithComplexHbmAliasInjectionAsync()
 			Country country = await (LoadCountryWithNativeSQLAsync(CreateCountry(stats), "LoadAreaStatisticsWithComplexHbmAliasInjection"));
 
 			Assert.That(country, Is.Not.Null);
-			Assert.That((ICollection) country.Statistics.Keys, Is.EquivalentTo((ICollection) stats.Keys), "Keys");
-			Assert.That((ICollection) country.Statistics.Values, Is.EquivalentTo((ICollection) stats.Values), "Elements");
+			Assert.That(country.Statistics.Keys, Is.EquivalentTo(stats.Keys), "Keys");
+			Assert.That(country.Statistics.Values, Is.EquivalentTo(stats.Values), "Elements");
 			await (CleanupWithPersonsAsync());
 		}
 
@@ -75,8 +75,8 @@ public async Task LoadCompositeElementsWithWithCustomAliasesAsync()
 			Country country = await (LoadCountryWithNativeSQLAsync(CreateCountry(stats), "LoadAreaStatisticsWithCustomAliases"));
 
 			Assert.That(country, Is.Not.Null);
-			Assert.That((ICollection) country.Statistics.Keys, Is.EquivalentTo((ICollection) stats.Keys), "Keys");
-			Assert.That((ICollection) country.Statistics.Values, Is.EquivalentTo((ICollection) stats.Values), "Elements");
+			Assert.That(country.Statistics.Keys, Is.EquivalentTo(stats.Keys), "Keys");
+			Assert.That(country.Statistics.Values, Is.EquivalentTo(stats.Values), "Elements");
 
 			await (CleanupWithPersonsAsync());
 		}
@@ -201,8 +201,8 @@ public async Task LoadCompositeElementCollectionWithCustomLoaderAsync()
 			{
 				var a = await (session.GetAsync<Area>(country.Code));
 				Assert.That(a, Is.Not.Null, "area");
-				Assert.That((ICollection) a.Statistics.Keys, Is.EquivalentTo((ICollection) stats.Keys), "area.Keys");
-				Assert.That((ICollection) a.Statistics.Values, Is.EquivalentTo((ICollection) stats.Values), "area.Elements");
+				Assert.That(a.Statistics.Keys, Is.EquivalentTo(stats.Keys), "area.Keys");
+				Assert.That(a.Statistics.Values, Is.EquivalentTo(stats.Values), "area.Elements");
 			}
 			await (CleanupWithPersonsAsync());
 		}
@@ -428,4 +428,4 @@ private static IDictionary<int, AreaStatistics> CreateStatistics()
 
 		#endregion
 	}
-}
+}

src/NHibernate.Test/Async/NHSpecificTest/NH2319/MapFixture.cs

@@ -0,0 +1,299 @@
+//------------------------------------------------------------------------------
+// <auto-generated>
+//     This code was generated by AsyncGenerator.
+//
+//     Changes to this file may cause incorrect behavior and will be lost if
+//     the code is regenerated.
+// </auto-generated>
+//------------------------------------------------------------------------------
+
+
+using System;
+using System.Linq;
+using System.Reflection;
+using NHibernate.Cfg;
+using NHibernate.Cfg.MappingSchema;
+using NHibernate.Collection;
+using NHibernate.Engine.Query;
+using NHibernate.Mapping.ByCode;
+using NHibernate.Util;
+using NUnit.Framework;
+using NHibernate.Linq;
+
+namespace NHibernate.Test.NHSpecificTest.NH2319
+{
+	using System.Threading.Tasks;
+	using System.Threading;
+	[TestFixture]
+	public class MapFixtureAsync : TestCaseMappingByCode
+	{
+		private Guid _parent1Id;
+		private Guid _child1Id;
+		private Guid _parent2Id;
+		private Guid _child3Id;
+
+		[Test]
+		public Task ShouldBeAbleToFindChildrenByNameAsync()
+		{
+			return FindChildrenByNameAsync(_parent1Id, _child1Id);
+		}
+
+		private async Task FindChildrenByNameAsync(Guid parentId, Guid childId, CancellationToken cancellationToken = default(CancellationToken))
+		{
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var parent = await (session.GetAsync<Parent>(parentId, cancellationToken));
+
+				Assert.That(parent, Is.Not.Null);
+
+				var filtered = await (parent.ChildrenMap.Values
+					.AsQueryable()
+					.Where(x => x.Name == "Jack")
+					.ToListAsync(cancellationToken));
+
+				Assert.That(filtered, Has.Count.EqualTo(1));
+				Assert.That(filtered[0].Id, Is.EqualTo(childId));
+			}
+		}
+
+		[Test]
+		public async Task ShouldBeAbleToPerformComplexFilteringAsync()
+		{
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var parent = await (session.GetAsync<Parent>(_parent1Id));
+
+				Assert.NotNull(parent);
+
+				var filtered = await (parent.ChildrenMap.Values
+					.AsQueryable()
+					.Where(x => x.Name == "Piter")
+					.SelectMany(x => x.GrandChildren)
+					.Select(x => x.Id)
+					.CountAsync());
+
+				Assert.That(filtered, Is.EqualTo(2));
+			}
+		}
+
+		[Test]
+		public async Task ShouldBeAbleToReuseQueryPlanAsync()
+		{
+			await (ShouldBeAbleToFindChildrenByNameAsync());
+			using (var spy = new LogSpy(typeof(QueryPlanCache)))
+			{
+				Assert.That(ShouldBeAbleToFindChildrenByNameAsync, Throws.Nothing);
+				AssertFilterPlanCacheHit(spy);
+			}
+		}
+
+		[Test]
+		public async Task ShouldNotMixResultsAsync()
+		{
+			await (FindChildrenByNameAsync(_parent1Id, _child1Id));
+			using (var spy = new LogSpy(typeof(QueryPlanCache)))
+			{
+				await (FindChildrenByNameAsync(_parent2Id, _child3Id));
+				AssertFilterPlanCacheHit(spy);
+			}
+		}
+
+		[Test]
+		public async Task ShouldNotInitializeCollectionWhenPerformingQueryAsync()
+		{
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var parent = await (session.GetAsync<Parent>(_parent1Id));
+				Assert.That(parent, Is.Not.Null);
+
+				var persistentCollection = (IPersistentCollection) parent.ChildrenMap;
+
+				var filtered = await (parent.ChildrenMap.Values
+					.AsQueryable()
+					.Where(x => x.Name == "Jack")
+					.ToListAsync());
+
+				Assert.That(filtered, Has.Count.EqualTo(1));
+				Assert.That(persistentCollection.WasInitialized, Is.False);
+			}
+		}
+
+		[Test]
+		public async Task ShouldPerformSqlQueryEvenIfCollectionAlreadyInitializedAsync()
+		{
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var parent = await (session.GetAsync<Parent>(_parent1Id));
+				Assert.That(parent, Is.Not.Null);
+
+				var loaded = parent.ChildrenMap.ToList();
+				Assert.That(loaded, Has.Count.EqualTo(2));
+
+				var countBeforeFiltering = session.SessionFactory.Statistics.QueryExecutionCount;
+
+				var filtered = await (parent.ChildrenMap.Values
+					.AsQueryable()
+					.Where(x => x.Name == "Jack")
+					.ToListAsync());
+
+				var countAfterFiltering = session.SessionFactory.Statistics.QueryExecutionCount;
+
+				Assert.That(filtered, Has.Count.EqualTo(1));
+				Assert.That(countAfterFiltering, Is.EqualTo(countBeforeFiltering + 1));
+			}
+		}
+
+		[Test]
+		public async Task TestFilterAsync()
+		{
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var parent = await (session.GetAsync<Parent>(_parent1Id));
+				Assert.That(parent, Is.Not.Null);
+
+				var children = await ((await (session.CreateFilterAsync(parent.ChildrenMap, "where this.Name = 'Jack'")))
+					.ListAsync<Child>());
+
+				Assert.That(children, Has.Count.EqualTo(1));
+			}
+		}
+
+		[Test]
+		public async Task TestPlanCacheMissAsync()
+		{
+			var internalPlanCache = typeof(QueryPlanCache)
+				.GetField("planCache", BindingFlags.NonPublic | BindingFlags.Instance)
+				?.GetValue(Sfi.QueryPlanCache) as SoftLimitMRUCache;
+			Assert.That(internalPlanCache, Is.Not.Null,
+				$"Unable to find the internal query plan cache for clearing it, please adapt code to current {nameof(QueryPlanCache)} implementation.");
+
+			using (var spy = new LogSpy(typeof(QueryPlanCache)))
+			{
+				internalPlanCache.Clear();
+				await (ShouldBeAbleToFindChildrenByNameAsync());
+				AssertFilterPlanCacheMiss(spy);
+			}
+		}
+
+		private const string _filterPlanCacheMissLog = "unable to locate collection-filter query plan in cache";
+
+		private static void AssertFilterPlanCacheHit(LogSpy spy) =>
+			// Each query currently ask the cache two times, so asserting reuse requires to check cache has not been missed
+			// rather than only asserting it has been hit.
+			Assert.That(spy.GetWholeLog(),
+				Contains.Substring("located collection-filter query plan in cache (")
+				.And.Not.Contains(_filterPlanCacheMissLog));
+
+		private static void AssertFilterPlanCacheMiss(LogSpy spy) =>
+			Assert.That(spy.GetWholeLog(), Contains.Substring(_filterPlanCacheMissLog));
+
+		protected override void Configure(Configuration configuration)
+		{
+			configuration.SetProperty("show_sql", "true");
+			configuration.SetProperty("generate_statistics", "true");
+		}
+
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				var parent1 = new Parent { Name = "Bob" };
+				_parent1Id = (Guid) session.Save(parent1);
+
+				var parent2 = new Parent { Name = "Martin" };
+				_parent2Id = (Guid) session.Save(parent2);
+
+				var child1 = new Child
+				{
+					Name = "Jack",
+					Parent = parent1
+				};
+				_child1Id = (Guid) session.Save(child1);
+				parent1.ChildrenMap.Add(child1.Id, child1);
+
+				var child2 = new Child
+				{
+					Name = "Piter",
+					Parent = parent1
+				};
+				session.Save(child2);
+				parent1.ChildrenMap.Add(child2.Id, child2);
+
+				var grandChild1 = new GrandChild
+				{
+					Name = "Kate",
+					Child = child2
+				};
+				session.Save(grandChild1);
+				child2.GrandChildren.Add(grandChild1);
+
+				var grandChild2 = new GrandChild
+				{
+					Name = "Mary",
+					Child = child2
+				};
+				session.Save(grandChild2);
+				child2.GrandChildren.Add(grandChild2);
+
+				var child3 = new Child
+				{
+					Name = "Jack",
+					Parent = parent2
+				};
+				_child3Id = (Guid) session.Save(child3);
+				parent2.ChildrenMap.Add(child1.Id, child3);
+
+				session.Flush();
+				transaction.Commit();
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				session.Delete("from System.Object");
+
+				session.Flush();
+				transaction.Commit();
+			}
+		}
+
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+			mapper.Class<Parent>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Name);
+				rc.Map(x => x.ChildrenMap,
+					map => map.Cascade(Mapping.ByCode.Cascade.All | Mapping.ByCode.Cascade.DeleteOrphans),
+					rel => rel.OneToMany());
+			});
+
+			mapper.Class<Child>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Name);
+				rc.Set(x => x.GrandChildren,
+					map => map.Cascade(Mapping.ByCode.Cascade.All | Mapping.ByCode.Cascade.DeleteOrphans),
+					rel => rel.OneToMany());
+			});
+
+			mapper.Class<GrandChild>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Name);
+			});
+
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+	}
+}