Added compatiblity mode

benchmarks/EntityFrameworkCore.Projectables.Benchmarks/Helpers/TestDbContext.cs

@@ -0,0 +1,37 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.EntityFrameworkCore;
+using EntityFrameworkCore.Projectables.Extensions;
+using EntityFrameworkCore.Projectables.Infrastructure;
+
+namespace EntityFrameworkCore.Projectables.Benchmarks.Helpers
+{
+    class TestDbContext : DbContext
+    {
+        readonly bool _useProjectables;
+        readonly bool _useFullCompatibiltyMode;
+
+        public TestDbContext(bool useProjectables, bool useFullCompatibiltyMode = true)
+        {
+            _useProjectables = useProjectables;
+            _useFullCompatibiltyMode = useFullCompatibiltyMode;
+        }
+
+        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+        {
+            optionsBuilder.UseSqlServer("Server=(localdb)\\MSSQLLocalDB;Database=ReadmeSample;Trusted_Connection=True");
+
+            if (_useProjectables)
+            {
+                optionsBuilder.UseProjectables(projectableOptions => {
+                    projectableOptions.CompatibilityMode(_useFullCompatibiltyMode ? CompatibilityMode.Full : CompatibilityMode.Limited);
+                });
+            }
+        }
+
+        public DbSet<TestEntity> Entities => Set<TestEntity>();
+    }
+}

benchmarks/EntityFrameworkCore.Projectables.Benchmarks/Helpers/TestEntity.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace EntityFrameworkCore.Projectables.Benchmarks.Helpers
+{
+    public class TestEntity
+    {
+        public int Id { get; set; }
+
+        [Projectable]
+        public int IdPlus1 => Id + 1;
+    }
+}

benchmarks/EntityFrameworkCore.Projectables.Benchmarks/PlainOverhead.cs

@@ -1,40 +1,16 @@
 using System;
+using System.IO.Compression;
 using System.Linq;
 using BenchmarkDotNet.Attributes;
+using EntityFrameworkCore.Projectables.Benchmarks.Helpers;
 using EntityFrameworkCore.Projectables.Extensions;
+using EntityFrameworkCore.Projectables.Infrastructure;
 using Microsoft.EntityFrameworkCore;
 
 namespace EntityFrameworkCore.Projectables.Benchmarks
 {
     public class PlainOverhead
     {
-        class TestEntity
-        {
-            public int Id { get; set; }
-        }
-
-        class TestDbContext : DbContext
-        {
-            readonly bool _useProjectables;
-
-            public TestDbContext(bool useProjectables)
-            {
-                _useProjectables = useProjectables;
-            }
-
-            protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
-            {
-                optionsBuilder.UseSqlServer("Server=(localdb)\\MSSQLLocalDB;Database=ReadmeSample;Trusted_Connection=True");
-                
-                if (_useProjectables)
-                {
-                    optionsBuilder.UseProjectables();
-                }
-            }
-
-            public DbSet<TestEntity> Entities => Set<TestEntity>();
-        }
-
         [Benchmark(Baseline = true)]
         public void WithoutProjectables()
         {
@@ -47,7 +23,7 @@ namespace EntityFrameworkCore.Projectables.Benchmarks
         }
 
         [Benchmark]
-        public void WithProjectables()
+        public void WithProjectablesWithFullCompatibility()
         {
             using var dbContext = new TestDbContext(true);
 
@@ -57,5 +33,17 @@ namespace EntityFrameworkCore.Projectables.Benchmarks
             }
         }
 
+
+        [Benchmark]
+        public void WithProjectablesWithLimitedCompatibility()
+        {
+            using var dbContext = new TestDbContext(true, false);
+
+            for (int i = 0; i < 10000; i++)
+            {
+                dbContext.Entities.Select(x => x.Id).ToQueryString();
+            }
+        }
+
     }
 }

benchmarks/EntityFrameworkCore.Projectables.Benchmarks/ProjectableProperties.cs

@@ -1,43 +1,15 @@
 using System;
 using System.Linq;
 using BenchmarkDotNet.Attributes;
+using EntityFrameworkCore.Projectables.Benchmarks.Helpers;
 using EntityFrameworkCore.Projectables.Extensions;
+using EntityFrameworkCore.Projectables.Infrastructure;
 using Microsoft.EntityFrameworkCore;
 
 namespace EntityFrameworkCore.Projectables.Benchmarks
 {
     public class ProjectableProperties
     {
-        public class TestEntity
-        {
-            public int Id { get; set; }
-
-            [Projectable]
-            public int IdPlus1 => Id + 1;
-        }
-
-        class TestDbContext : DbContext
-        {
-            readonly bool _useProjectables;
-
-            public TestDbContext(bool useProjectables)
-            {
-                _useProjectables = useProjectables;
-            }
-
-            protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
-            {
-                optionsBuilder.UseSqlServer("Server=(localdb)\\MSSQLLocalDB;Database=ReadmeSample;Trusted_Connection=True");
-                
-                if (_useProjectables)
-                {
-                    optionsBuilder.UseProjectables();
-                }
-            }
-
-            public DbSet<TestEntity> Entities => Set<TestEntity>();
-        }
-
         [Benchmark(Baseline = true)]
         public void WithoutProjectables()
         {
@@ -50,7 +22,7 @@ namespace EntityFrameworkCore.Projectables.Benchmarks
         }
 
         [Benchmark]
-        public void WithProjectables()
+        public void WithProjectablesWithFullCompatibility()
         {
             using var dbContext = new TestDbContext(true);
 
@@ -60,5 +32,15 @@ namespace EntityFrameworkCore.Projectables.Benchmarks
             }
         }
 
+        [Benchmark]
+        public void WithProjectablesWithLimitedCompatibility()
+        {
+            using var dbContext = new TestDbContext(true, false);
+
+            for (int i = 0; i < 10000; i++)
+            {
+                dbContext.Entities.Select(x => x.IdPlus1).ToQueryString();
+            }
+        }
     }
 }

src/EntityFrameworkCore.Projectables/Extensions/DbContextOptionsExtensions.cs

@@ -1,4 +1,5 @@
-using EntityFrameworkCore.Projectables.Infrastructure.Internal;
+using EntityFrameworkCore.Projectables.Infrastructure;
+using EntityFrameworkCore.Projectables.Infrastructure.Internal;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Infrastructure;
 using System;
@@ -12,15 +13,17 @@ namespace EntityFrameworkCore.Projectables.Extensions
 {
     public static class DbContextOptionsExtensions
     {
-        public static DbContextOptionsBuilder<TContext> UseProjectables<TContext>(this DbContextOptionsBuilder<TContext> optionsBuilder)
+        public static DbContextOptionsBuilder<TContext> UseProjectables<TContext>(this DbContextOptionsBuilder<TContext> optionsBuilder, Action<ProjectableOptionsBuilder>? configure = null)
             where TContext : DbContext
-            => (DbContextOptionsBuilder<TContext>)UseProjectables((DbContextOptionsBuilder)optionsBuilder);
+            => (DbContextOptionsBuilder<TContext>)UseProjectables((DbContextOptionsBuilder)optionsBuilder, configure);
 
-        public static DbContextOptionsBuilder UseProjectables(this DbContextOptionsBuilder optionsBuilder)
+        public static DbContextOptionsBuilder UseProjectables(this DbContextOptionsBuilder optionsBuilder, Action<ProjectableOptionsBuilder>? configure = null)
         {
             var extension = optionsBuilder.Options.FindExtension<ProjectionOptionsExtension>() ?? new ProjectionOptionsExtension();
             ((IDbContextOptionsBuilderInfrastructure)optionsBuilder).AddOrUpdateExtension(extension);
 
+            configure?.Invoke(new ProjectableOptionsBuilder(optionsBuilder));
+
             return optionsBuilder;
         }
     }

src/EntityFrameworkCore.Projectables/Infrastructure/CompatibilityMode.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace EntityFrameworkCore.Projectables.Infrastructure
+{
+    public enum CompatibilityMode
+    {
+        Full,
+        Limited
+    }
+}

src/EntityFrameworkCore.Projectables/Infrastructure/Internal/CustomQueryTranslationPreprocessorFactory.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Linq.Expressions;
+using System.Text;
+using System.Threading.Tasks;
+using EntityFrameworkCore.Projectables.Services;
+using Microsoft.EntityFrameworkCore.Query;
+
+namespace EntityFrameworkCore.Projectables.Infrastructure.Internal
+{
+    public class CustomQueryTranslationPreprocessorFactory : IQueryTranslationPreprocessorFactory
+    {
+        readonly IQueryTranslationPreprocessorFactory _decoratedFactory;
+        readonly QueryTranslationPreprocessorDependencies _queryTranslationPreprocessorDependencies;
+        readonly ProjectableExpressionReplacer _projectableExpressionReplacer = new(new ProjectionExpressionResolver());
+
+        public CustomQueryTranslationPreprocessorFactory(IQueryTranslationPreprocessorFactory decoratedFactory, QueryTranslationPreprocessorDependencies queryTranslationPreprocessorDependencies)
+        {
+            _decoratedFactory = decoratedFactory;
+            _queryTranslationPreprocessorDependencies = queryTranslationPreprocessorDependencies;
+        }
+
+        public QueryTranslationPreprocessor Create(QueryCompilationContext queryCompilationContext)
+            => new CustomQueryTranslationPreprocessor(_queryTranslationPreprocessorDependencies, queryCompilationContext, _projectableExpressionReplacer);
+    }
+
+    public class CustomQueryTranslationPreprocessor : QueryTranslationPreprocessor
+    {
+        readonly ProjectableExpressionReplacer _projectableExpressionReplacer;
+
+        public CustomQueryTranslationPreprocessor(QueryTranslationPreprocessorDependencies dependencies, QueryCompilationContext queryCompilationContext, ProjectableExpressionReplacer projectableExpressionReplacer) : base(dependencies, queryCompilationContext)
+        {
+            _projectableExpressionReplacer = projectableExpressionReplacer;
+        }
+
+        public override Expression Process(Expression query)
+            => base.Process(_projectableExpressionReplacer.Visit(query));
+    }
+}

src/EntityFrameworkCore.Projectables/Infrastructure/Internal/ProjectionOptionsExtension.cs

@@ -14,11 +14,21 @@ namespace EntityFrameworkCore.Projectables.Infrastructure.Internal
 {
     public class ProjectionOptionsExtension : IDbContextOptionsExtension
     {
+        CompatibilityMode _compatibilityMode = CompatibilityMode.Full;
+
         public ProjectionOptionsExtension()
         {
             Info = new ExtensionInfo(this);
         }
 
+        public ProjectionOptionsExtension(ProjectionOptionsExtension copyFrom)
+            : this()
+        {
+            _compatibilityMode = copyFrom._compatibilityMode;
+        }
+
+        protected ProjectionOptionsExtension Clone() => new(this);
+
         public DbContextOptionsExtensionInfo Info { get; }
 
         [System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "EF1001:Internal EF Core API usage.", Justification = "Needed")]
@@ -37,19 +47,47 @@ namespace EntityFrameworkCore.Projectables.Infrastructure.Internal
                 return ActivatorUtilities.GetServiceOrCreateInstance(services, descriptor.ImplementationType!);
             }
 
-            var targetDescriptor = services.FirstOrDefault(x => x.ServiceType == typeof(IQueryCompiler));
-            if (targetDescriptor is null)
+            if (_compatibilityMode is CompatibilityMode.Full)
             {
-                throw new InvalidOperationException("No QueryProvider is configured yet. Please make sure to configure a database provider first"); ;
-            }
-            
-            var decoratorObjectFactory = ActivatorUtilities.CreateFactory(typeof(CustomQueryProvider), new [] { targetDescriptor.ServiceType });
+                var targetDescriptor = services.FirstOrDefault(x => x.ServiceType == typeof(IQueryCompiler));
+                if (targetDescriptor is null)
+                {
+                    throw new InvalidOperationException("No QueryProvider is configured yet. Please make sure to configure a database provider first"); ;
+                }
 
-            services.Replace(ServiceDescriptor.Describe(
-                targetDescriptor.ServiceType,
-                serviceProvider => decoratorObjectFactory(serviceProvider, new[] { CreateTargetInstance(serviceProvider, targetDescriptor) }),
-                targetDescriptor.Lifetime
-            ));
+                var decoratorObjectFactory = ActivatorUtilities.CreateFactory(typeof(CustomQueryProvider), new[] { targetDescriptor.ServiceType });
+
+                services.Replace(ServiceDescriptor.Describe(
+                    targetDescriptor.ServiceType,
+                    serviceProvider => decoratorObjectFactory(serviceProvider, new[] { CreateTargetInstance(serviceProvider, targetDescriptor) }),
+                    targetDescriptor.Lifetime
+                ));
+            }
+            else
+            {
+                var targetDescriptor = services.FirstOrDefault(x => x.ServiceType == typeof(IQueryTranslationPreprocessorFactory));
+                if (targetDescriptor is null)
+                {
+                    throw new InvalidOperationException("No QueryTranslationPreprocessorFactory is configured yet. Please make sure to configure a database provider first"); ;
+                }
+
+                var decoratorObjectFactory = ActivatorUtilities.CreateFactory(typeof(CustomQueryTranslationPreprocessorFactory), new[] { targetDescriptor.ServiceType });
+
+                services.Replace(ServiceDescriptor.Describe(
+                    targetDescriptor.ServiceType,
+                    serviceProvider => decoratorObjectFactory(serviceProvider, new[] { CreateTargetInstance(serviceProvider, targetDescriptor) }),
+                    targetDescriptor.Lifetime
+                ));
+            }
+        }
+
+        public ProjectionOptionsExtension WithCompatibilityMode(CompatibilityMode compatibilityMode)
+        {
+            var clone = Clone();
+
+            clone._compatibilityMode = compatibilityMode;
+
+            return clone;
         }
 
         public void Validate(IDbContextOptions options)
@@ -58,13 +96,29 @@ namespace EntityFrameworkCore.Projectables.Infrastructure.Internal
 
         sealed class ExtensionInfo : DbContextOptionsExtensionInfo
         {
+            private int? _serviceProviderHash;
+
             public ExtensionInfo(IDbContextOptionsExtension extension) : base(extension)
             {
             }
 
             public override bool IsDatabaseProvider => false;
             public override string LogFragment => string.Empty;
-            public override long GetServiceProviderHashCode() => 0;
+            public override long GetServiceProviderHashCode()
+            {
+                if (_serviceProviderHash == null)
+                {
+                    var hashCode = nameof(ProjectionOptionsExtension).GetHashCode();
+
+                    var extension = (ProjectionOptionsExtension)Extension;
+
+                    hashCode ^= extension._compatibilityMode.GetHashCode();
+
+                    _serviceProviderHash = hashCode;
+                }
+
+                return _serviceProviderHash.Value;
+            }
             
             public override void PopulateDebugInfo(IDictionary<string, string> debugInfo)
             {
@@ -72,6 +126,8 @@ namespace EntityFrameworkCore.Projectables.Infrastructure.Internal
                 {
                     throw new ArgumentNullException(nameof(debugInfo));
                 }
+
+                debugInfo["Projectables:CompatibilityMode"] = ((ProjectionOptionsExtension)Extension)._compatibilityMode.ToString();
             }
         }
     }

src/EntityFrameworkCore.Projectables/Infrastructure/ProjectableOptionsBuilder.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using EntityFrameworkCore.Projectables.Infrastructure.Internal;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+
+namespace EntityFrameworkCore.Projectables.Infrastructure
+{
+    public class ProjectableOptionsBuilder
+    {
+        readonly DbContextOptionsBuilder _optionsBuilder;
+
+        public ProjectableOptionsBuilder(DbContextOptionsBuilder optionsBuilder)
+        {
+            _optionsBuilder = optionsBuilder ?? throw new ArgumentNullException(nameof(optionsBuilder));
+        }
+
+        public ProjectableOptionsBuilder CompatibilityMode(CompatibilityMode mode)
+            => WithOption(x => x.WithCompatibilityMode(mode));
+
+        /// <summary>
+        ///     Sets an option by cloning the extension used to store the settings. This ensures the builder
+        ///     does not modify options that are already in use elsewhere.
+        /// </summary>
+        /// <param name="setAction"> An action to set the option. </param>
+        /// <returns> The same builder instance so that multiple calls can be chained. </returns>
+        protected virtual ProjectableOptionsBuilder WithOption(Func<ProjectionOptionsExtension, ProjectionOptionsExtension> setAction)
+        {
+            ((IDbContextOptionsBuilderInfrastructure)_optionsBuilder).AddOrUpdateExtension(
+                setAction(_optionsBuilder.Options.FindExtension<ProjectionOptionsExtension>() ?? new ProjectionOptionsExtension()));
+
+            return this;
+        }
+    }
+}