Add a compiled slim model generator

Part of #1906

src/EFCore.Design/Design/DesignTimeServiceCollectionExtensions.cs

@@ -58,6 +58,8 @@ public static IServiceCollection AddEntityFrameworkDesignTimeServices(
                     .TryAddSingleton<IMigrationsCodeGeneratorSelector, MigrationsCodeGeneratorSelector>()
                     .TryAddSingleton<IModelCodeGenerator, CSharpModelGenerator>()
                     .TryAddSingleton<IModelCodeGeneratorSelector, ModelCodeGeneratorSelector>()
+                    .TryAddSingleton<ICompiledModelCodeGenerator, CSharpSlimModelCodeGenerator>()
+                    .TryAddSingleton<ICompiledModelCodeGeneratorSelector, CompiledModelCodeGeneratorSelector>()
                     .TryAddSingleton<INamedConnectionStringResolver>(
                         new DesignTimeConnectionStringResolver(applicationServiceProviderAccessor))
                     .TryAddSingleton<IPluralizer, HumanizerPluralizer>()

src/EFCore.Design/Design/Internal/CSharpHelper.cs

@@ -37,25 +37,6 @@ public CSharpHelper(IRelationalTypeMappingSource relationalTypeMappingSource)
             _relationalTypeMappingSource = relationalTypeMappingSource;
         }
 
-        private static readonly IReadOnlyDictionary<Type, string> _builtInTypes = new Dictionary<Type, string>
-        {
-            { typeof(bool), "bool" },
-            { typeof(byte), "byte" },
-            { typeof(sbyte), "sbyte" },
-            { typeof(char), "char" },
-            { typeof(short), "short" },
-            { typeof(int), "int" },
-            { typeof(long), "long" },
-            { typeof(ushort), "ushort" },
-            { typeof(uint), "uint" },
-            { typeof(ulong), "ulong" },
-            { typeof(decimal), "decimal" },
-            { typeof(float), "float" },
-            { typeof(double), "double" },
-            { typeof(string), "string" },
-            { typeof(object), "object" }
-        };
-
         private static readonly IReadOnlyCollection<string> _keywords = new[]
         {
             "__arglist",
@@ -166,7 +147,8 @@ public CSharpHelper(IRelationalTypeMappingSource relationalTypeMappingSource)
                 { typeof(uint), (c, v) => c.Literal((uint)v) },
                 { typeof(ulong), (c, v) => c.Literal((ulong)v) },
                 { typeof(ushort), (c, v) => c.Literal((ushort)v) },
-                { typeof(BigInteger), (c, v) => c.Literal((BigInteger)v) }
+                { typeof(BigInteger), (c, v) => c.Literal((BigInteger)v) },
+                { typeof(Type), (c, v) => c.Literal((Type)v) }
             };
 
         /// <summary>
@@ -215,50 +197,7 @@ private string Reference(Type type, bool useFullName)
         {
             Check.NotNull(type, nameof(type));
 
-            if (_builtInTypes.TryGetValue(type, out var builtInType))
-            {
-                return builtInType;
-            }
-
-            if (type.IsConstructedGenericType
-                && type.GetGenericTypeDefinition() == typeof(Nullable<>))
-            {
-                return Reference(type.UnwrapNullableType()) + "?";
-            }
-
-            var builder = new StringBuilder();
-
-            if (type.IsArray)
-            {
-                builder
-                    .Append(Reference(type.GetElementType()!))
-                    .Append('[');
-
-                var rank = type.GetArrayRank();
-                for (var i = 1; i < rank; i++)
-                {
-                    builder.Append(',');
-                }
-
-                builder.Append(']');
-
-                return builder.ToString();
-            }
-
-            if (type.IsNested)
-            {
-                Check.DebugAssert(type.DeclaringType != null, "DeclaringType is null");
-                builder
-                    .Append(Reference(type.DeclaringType))
-                    .Append('.');
-            }
-
-            builder.Append(
-                useFullName
-                    ? type.DisplayName()
-                    : type.ShortDisplayName());
-
-            return builder.ToString();
+            return type.DisplayName(fullName: useFullName, compilable: true);
         }
 
         /// <summary>
@@ -267,7 +206,7 @@ private string Reference(Type type, bool useFullName)
         ///     any release. You should only use it directly in your code with extreme caution and knowing that
         ///     doing so can result in application failures when updating to a new Entity Framework Core release.
         /// </summary>
-        public virtual string Identifier(string name, ICollection<string>? scope = null)
+        public virtual string Identifier(string name, ICollection<string>? scope = null, bool? capitalize = null)
         {
             Check.NotEmpty(name, nameof(name));
 
@@ -298,6 +237,11 @@ public virtual string Identifier(string name, ICollection<string>? scope = null)
                 builder.Insert(0, '_');
             }
 
+            if (capitalize != null)
+            {
+                ChangeFirstLetterCase(builder, capitalize.Value);
+            }
+
             var identifier = builder.ToString();
             if (scope != null)
             {
@@ -315,6 +259,20 @@ public virtual string Identifier(string name, ICollection<string>? scope = null)
             return _keywords.Contains(identifier) ? "@" + identifier : identifier;
         }
 
+        private static StringBuilder ChangeFirstLetterCase(StringBuilder builder, bool capitalize)
+        {
+            if (builder.Length == 0)
+            {
+                return builder;
+            }
+
+            var first = builder[index: 0];
+            builder.Remove(startIndex: 0, length: 1)
+                .Insert(index: 0, value: capitalize ? char.ToUpper(first) : char.ToLower(first));
+
+            return builder;
+        }
+
         /// <summary>
         ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
         ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
@@ -566,6 +524,15 @@ public virtual string Literal(ushort value)
         public virtual string Literal(BigInteger value)
             => $"BigInteger.Parse(\"{value.ToString(NumberFormatInfo.InvariantInfo)}\", NumberFormatInfo.InvariantInfo)";
 
+        /// <summary>
+        ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+        ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+        ///     any release. You should only use it directly in your code with extreme caution and knowing that
+        ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+        /// </summary>
+        public virtual string Literal(Type value)
+            => $"typeof({Reference(value)})";
+
         /// <summary>
         ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
         ///     the same compatibility standards as public APIs. It may be changed or removed without notice in

src/EFCore.Design/Design/Internal/LanguageBasedSelector.cs

@@ -42,19 +42,28 @@ protected LanguageBasedSelector(IEnumerable<T> services)
         ///     doing so can result in application failures when updating to a new Entity Framework Core release.
         /// </summary>
         public virtual T Select(string? language)
+            => Select(language, Services);
+
+        /// <summary>
+        ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+        ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+        ///     any release. You should only use it directly in your code with extreme caution and knowing that
+        ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+        /// </summary>
+        protected virtual T Select(string? language, IEnumerable<T> services)
         {
             if (string.IsNullOrEmpty(language))
             {
                 language = "C#";
             }
 
-            var legacyService = Services.LastOrDefault(s => s.Language == null);
+            var legacyService = services.LastOrDefault(s => s.Language == null);
             if (legacyService != null)
             {
                 return legacyService;
             }
 
-            var matches = Services.Where(s => string.Equals(s.Language, language, StringComparison.OrdinalIgnoreCase)).ToList();
+            var matches = services.Where(s => string.Equals(s.Language, language, StringComparison.OrdinalIgnoreCase)).ToList();
             if (matches.Count == 0)
             {
                 throw new OperationException(DesignStrings.NoLanguageService(language, typeof(T).ShortDisplayName()));

src/EFCore.Design/Migrations/Design/CSharpSnapshotGenerator.cs

@@ -100,19 +100,7 @@ public virtual void Generate(string builderName, IModel model, IndentedStringBui
                 GenerateSequence(builderName, sequence, stringBuilder);
             }
 
-            GenerateEntityTypes(builderName, Sort(model.GetEntityTypes()), stringBuilder);
-        }
-
-        private static IReadOnlyList<IEntityType> Sort(IEnumerable<IEntityType> entityTypes)
-        {
-            var entityTypeGraph = new Multigraph<IEntityType, int>();
-            entityTypeGraph.AddVertices(entityTypes);
-            foreach (var entityType in entityTypes.Where(et => et.BaseType != null))
-            {
-                entityTypeGraph.AddEdge(entityType.BaseType!, entityType, 0);
-            }
-
-            return entityTypeGraph.TopologicalSort();
+            GenerateEntityTypes(builderName, model.GetEntityTypesInHierarchicalOrder(), stringBuilder);
         }
 
         /// <summary>

src/EFCore.Design/Migrations/Internal/MigrationsCodeGeneratorSelector.cs

@@ -25,22 +25,5 @@ public MigrationsCodeGeneratorSelector(IEnumerable<IMigrationsCodeGenerator> ser
             : base(services)
         {
         }
-
-        /// <summary>
-        ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
-        ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
-        ///     any release. You should only use it directly in your code with extreme caution and knowing that
-        ///     doing so can result in application failures when updating to a new Entity Framework Core release.
-        /// </summary>
-        public virtual IMigrationsCodeGenerator? Override { get; set; }
-
-        /// <summary>
-        ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
-        ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
-        ///     any release. You should only use it directly in your code with extreme caution and knowing that
-        ///     doing so can result in application failures when updating to a new Entity Framework Core release.
-        /// </summary>
-        public override IMigrationsCodeGenerator Select(string? language)
-            => Override ?? base.Select(language);
     }
 }

src/EFCore.Design/Properties/DesignStrings.resx

@@ -132,6 +132,27 @@
   <data name="CannotFindTypeMappingForColumn" xml:space="preserve">
     <value>Could not find type mapping for column '{columnName}' with data type '{dateType}'. Skipping column.</value>
   </data>
+  <data name="CompiledModelConstructorBinding" xml:space="preserve">
+    <value>The entity type '{entityType}' has a custom constructor binding. This is usually caused by using proxies. Compiled model can't be generated, because custom constructor bindings are not supported.</value>
+  </data>
+  <data name="CompiledModelDefiningQuery" xml:space="preserve">
+    <value>The entity type '{entityType}' has a defining query configured. Compiled model can't be generated, because defining queries are not supported.</value>
+  </data>
+  <data name="CompiledModelQueryFilter" xml:space="preserve">
+    <value>The entity type '{entityType}' has a query filter configured. Compiled model can't be generated, because query filters are not supported.</value>
+  </data>
+  <data name="CompiledModelTypeMapping" xml:space="preserve">
+    <value>The property '{entityType}.{property}' has a custom type mapping configured. Compiled model can't be generated, because custom type mappings are not supported.</value>
+  </data>
+  <data name="CompiledModelValueComparer" xml:space="preserve">
+    <value>The property '{entityType}.{property}' has a value comparer configured. Compiled model can't be generated, because value comparers are not supported.</value>
+  </data>
+  <data name="CompiledModelValueConverter" xml:space="preserve">
+    <value>The property '{entityType}.{property}' has a value converter configured. Compiled model can't be generated, because value converters are not supported.</value>
+  </data>
+  <data name="CompiledModelValueGenerator" xml:space="preserve">
+    <value>The property '{entityType}.{property}' has a value generator configured. Compiled model can't be generated, because value generators are not supported.</value>
+  </data>
   <data name="ConflictingContextAndMigrationName" xml:space="preserve">
     <value>The name you have chosen for the migration, '{name}', is the same as the context class name. Please choose a different name for your migration. Might we suggest 'InitialCreate' for your first migration?</value>
   </data>

src/EFCore.Design/Scaffolding/CompiledModelCodeGenerationOptions.cs

@@ -0,0 +1,31 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+
+namespace Microsoft.EntityFrameworkCore.Scaffolding
+{
+    /// <summary>
+    ///     Represents the options to use while generating code for compiled model metadata.
+    /// </summary>
+    public class CompiledModelCodeGenerationOptions
+    {
+        /// <summary>
+        ///     Gets or sets the namespace for model metadata classes.
+        /// </summary>
+        /// <value> The namespace for model metadata classes. </value>
+        public virtual string ModelNamespace { get; set; } = null!;
+
+        /// <summary>
+        ///     Gets or sets the type of the corresponding DbContext.
+        /// </summary>
+        /// <value> The type of the corresponding DbContext. </value>
+        public virtual Type ContextType { get; set; } = null!;
+
+        /// <summary>
+        ///     Gets or sets the programming language to scaffold for.
+        /// </summary>
+        /// <value> The programming language to scaffold for. </value>
+        public virtual string? Language { get; set; }
+    }
+}

src/EFCore.Design/Scaffolding/ICompiledModelCodeGenerator.cs

@@ -0,0 +1,25 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Collections.Generic;
+using Microsoft.EntityFrameworkCore.Design;
+using Microsoft.EntityFrameworkCore.Metadata;
+
+namespace Microsoft.EntityFrameworkCore.Scaffolding
+{
+    /// <summary>
+    ///     Used to generate code for compiled model metadata.
+    /// </summary>
+    public interface ICompiledModelCodeGenerator : ILanguageBasedService
+    {
+        /// <summary>
+        ///     Generates code for compiled model metadata.
+        /// </summary>
+        /// <param name="model"> The source model. </param>
+        /// <param name="options"> The options to use during generation. </param>
+        /// <returns> The generated model metadata files. </returns>
+        IReadOnlyCollection<ScaffoldedFile> GenerateModel(
+            IModel model,
+            CompiledModelCodeGenerationOptions options);
+    }
+}