Add a benchmark of LINQ queries impacted by the change.

Author: fredericDelaporte

src/NHibernate.Test/Async/NHSpecificTest/GH1547/Fixture.cs

@@ -0,0 +1,193 @@
+//------------------------------------------------------------------------------
+// <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.Collections.Generic;
+using System.Data;
+using System.Data.Common;
+using System.Diagnostics;
+using System.Linq;
+using System.Reflection;
+using NHibernate.Cfg;
+using NHibernate.Driver;
+using NHibernate.Engine;
+using NHibernate.Engine.Query;
+using NHibernate.SqlCommand;
+using NHibernate.SqlTypes;
+using NHibernate.Util;
+using NSubstitute;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH1547
+{
+	using System.Threading.Tasks;
+	using System.Threading;
+	[TestFixture, Explicit("Contains only performances benchmark")]
+	public class FixtureAsync : BugTestCase
+	{
+		protected override void Configure(Configuration configuration)
+		{
+			base.Configure(configuration);
+
+			var driverClass = ReflectHelper.ClassForName(configuration.GetProperty(Cfg.Environment.ConnectionDriver));
+			DriverForSubstitutedCommand.DriverClass = driverClass;
+
+			configuration.SetProperty(
+				Cfg.Environment.ConnectionDriver,
+				typeof(DriverForSubstitutedCommand).AssemblyQualifiedName);
+		}
+
+		protected override void DropSchema()
+		{
+			(Sfi.ConnectionProvider.Driver as DriverForSubstitutedCommand)?.CleanUp();
+			base.DropSchema();
+		}
+
+		[Test]
+		public Task SimpleLinqPerfAsync()
+		{
+			return BenchmarkAsync(
+				"Simple LINQ",
+				s =>
+					s
+						.Query<Entity>()
+						.Where(e => e.Name == "Bob"));
+		}
+
+		[Test]
+		public Task LinqWithNonParameterizedConstantPerfAsync()
+		{
+			return BenchmarkAsync(
+				"Non parameterized constant",
+				s =>
+					s
+						.Query<Entity>()
+						.Where(e => e.Name == "Bob")
+						.Select(e => new { e, c = 2 }));
+		}
+
+		[Test]
+		public Task LinqWithListParameterPerfAsync()
+		{
+			try
+			{
+				var names = new[] { "Bob", "Sally" };
+				return BenchmarkAsync(
+				"List parameter",
+				s =>
+					s
+						.Query<Entity>()
+						.Where(e => names.Contains(e.Name)));
+			}
+			catch (Exception ex)
+			{
+				return Task.FromException<object>(ex);
+			}
+		}
+
+		private async Task BenchmarkAsync<T>(string test, Func<ISession, IQueryable<T>> queryFactory, CancellationToken cancellationToken = default(CancellationToken))
+		{
+			var driver = (DriverForSubstitutedCommand) Sfi.ConnectionProvider.Driver;
+			var timings = new List<double>();
+			var sw = new Stopwatch();
+
+			var cache = (SoftLimitMRUCache)
+				typeof(QueryPlanCache)
+					.GetField("planCache", BindingFlags.Instance | BindingFlags.NonPublic)
+					.GetValue(Sfi.QueryPlanCache);
+
+			using (var session = OpenSession())
+			using (var tx = session.BeginTransaction())
+			{
+				using (driver.SubstituteCommand())
+				{
+					var query = queryFactory(session);
+					// Warm up.
+					await (RunBenchmarkUnitAsync(cache, query));
+
+					for (var j = 0; j < 1000; j++)
+					{
+						sw.Restart();
+						await (RunBenchmarkUnitAsync(cache, query));
+						sw.Stop();
+						timings.Add(sw.Elapsed.TotalMilliseconds);
+					}
+				}
+
+				await (tx.CommitAsync(cancellationToken));
+			}
+
+			var avg = timings.Average();
+			Console.WriteLine(
+				$"{test} average time: {avg}ms (s {Math.Sqrt(timings.Sum(t => Math.Pow(t - avg, 2)) / (timings.Count - 1))}ms)");
+		}
+
+		private static Task RunBenchmarkUnitAsync<T>(SoftLimitMRUCache cache, IQueryable<T> query)
+		{
+			try
+			{
+				// Do enough iterations for having a significant elapsed time in milliseconds.
+				for (var i = 0; i < 20; i++)
+				{
+					// Always clear the query plan cache before running the query, otherwise the impact of 1547
+					// change would be hidden by it. Simulates having many different queries run.
+					cache.Clear();
+					Assert.That(query.ToList, Throws.Nothing);
+				}
+				return Task.CompletedTask;
+			}
+			catch (Exception ex)
+			{
+				return Task.FromException<object>(ex);
+			}
+		}
+	}
+
+	public partial class DriverForSubstitutedCommand : IDriver
+	{
+
+		#region Firebird mess
+
+		#endregion
+		#region Pure forwarding
+
+		#endregion
+
+		private partial class SubstituteDbCommand : DbCommand
+		{
+
+			protected override Task<DbDataReader> ExecuteDbDataReaderAsync(CommandBehavior behavior, CancellationToken cancellationToken)
+			{
+				try
+				{
+					return Task.FromResult<DbDataReader>(_substituteReader);
+				}
+				catch (Exception ex)
+				{
+					return Task.FromException<DbDataReader>(ex);
+				}
+			}
+
+			public override Task<int> ExecuteNonQueryAsync(CancellationToken cancellationToken)
+			{
+				return Task.FromResult<int>(0);
+			}
+
+			public override Task<object> ExecuteScalarAsync(CancellationToken cancellationToken)
+			{
+				return Task.FromResult<object>(null);
+			}
+
+			#region Pure forwarding
+
+			#endregion
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/GH1547/Entity.cs

@@ -0,0 +1,10 @@
+using System;
+
+namespace NHibernate.Test.NHSpecificTest.GH1547
+{
+	class Entity
+	{
+		public virtual Guid Id { get; set; }
+		public virtual string Name { get; set; }
+	}
+}