perf: memoize type resolution; skip and source-generate JSON work

ModernUO.Serialization.Generator/EntitySerializationGenerator.cs

@@ -123,11 +123,14 @@ CancellationToken token
         var builder = ImmutableArray.CreateBuilder<SerializableProperty>(properties.Length);
         foreach (var property in properties)
         {
+            // The fact only affects the nullable suffix on save-flagged content struct fields.
             builder.Add(
-                property with
-                {
-                    TypeIsValueType = compilation.GetTypeByMetadataName(property.Type)?.IsValueType == true
-                }
+                property.UsesSaveFlag != true
+                    ? property
+                    : property with
+                    {
+                        TypeIsValueType = compilation.GetCachedTypeByMetadataName(property.Type)?.IsValueType == true
+                    }
             );
         }
 

ModernUO.Serialization.Generator/SerializableEntityGeneration/SerializableEntityGeneration.BuildModel.cs

@@ -378,7 +378,7 @@ SerializationModelResult Fail(DiagnosticDescriptor descriptor, params object[] a
 
                 var invalidateProperties = allAttributes.Any(
                     attr => attr.AttributeClass?.Equals(
-                        compilation.GetTypeByMetadataName(SymbolMetadata.INVALIDATE_PROPERTIES_ATTRIBUTE),
+                        compilation.GetCachedTypeByMetadataName(SymbolMetadata.INVALIDATE_PROPERTIES_ATTRIBUTE),
                         SymbolEqualityComparer.Default
                     ) ?? false
                 );
@@ -502,7 +502,7 @@ SerializationModelResult Fail(DiagnosticDescriptor descriptor, params object[] a
                 .FirstOrDefault(
                     a => SymbolEqualityComparer.Default.Equals(
                         a.AttributeClass,
-                        compilation.GetTypeByMetadataName(SymbolMetadata.AFTER_DESERIALIZATION_ATTRIBUTE)
+                        compilation.GetCachedTypeByMetadataName(SymbolMetadata.AFTER_DESERIALIZATION_ATTRIBUTE)
                     )
                 );
 

ModernUO.Serialization.Generator/SerializableMigration/MigrationJsonContext.cs

@@ -0,0 +1,29 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright 2019-2026 - ModernUO Development Team                       *
+ * Email: hi@modernuo.com                                                *
+ * File: MigrationJsonContext.cs                                         *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+using System.Text.Json.Serialization;
+
+namespace ModernUO.Serialization.Generator;
+
+/// <summary>
+/// Source-generated serializer metadata for the migration schema types, so parsing thousands
+/// of migration files never pays reflection-based metadata construction inside the analyzer
+/// process.
+/// </summary>
+[JsonSerializable(typeof(SerializableMetadata))]
+[JsonSerializable(typeof(SerializableProperty))]
+internal partial class MigrationJsonContext : JsonSerializerContext
+{
+}

ModernUO.Serialization.Generator/SerializableMigration/SerializableMigrationSchema.cs

@@ -29,7 +29,8 @@ public static class SerializableMigrationSchema
             AllowTrailingCommas = true,
             DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
             ReadCommentHandling = JsonCommentHandling.Skip,
-            NewLine = "\n" // Force all json files to \n line endings
+            NewLine = "\n", // Force all json files to \n line endings
+            TypeInfoResolver = MigrationJsonContext.Default
         }
     );
 

ModernUO.Serialization.Generator/SourceGeneration/SymbolMetadata/KnownTypeCache.cs

@@ -0,0 +1,45 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright 2019-2026 - ModernUO Development Team                       *
+ * Email: hi@modernuo.com                                                *
+ * File: KnownTypeCache.cs                                               *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+using System.Collections.Concurrent;
+using System.Runtime.CompilerServices;
+using Microsoft.CodeAnalysis;
+
+namespace ModernUO.Serialization.Generator;
+
+/// <summary>
+/// Per-compilation memoization for <see cref="Compilation.GetTypeByMetadataName" />, which
+/// walks assemblies on every call. The transforms resolve the same handful of names per field
+/// per class per compilation; this collapses those to dictionary hits. Keyed weakly so
+/// discarded compilations do not pin their symbols.
+/// </summary>
+public static class KnownTypeCache
+{
+    private static readonly ConditionalWeakTable<Compilation, ConcurrentDictionary<string, INamedTypeSymbol>> _cache =
+        new();
+
+    public static INamedTypeSymbol GetCachedTypeByMetadataName(this Compilation compilation, string metadataName)
+    {
+        var types = _cache.GetOrCreateValue(compilation);
+
+        if (!types.TryGetValue(metadataName, out var symbol))
+        {
+            symbol = compilation.GetTypeByMetadataName(metadataName);
+            types.TryAdd(metadataName, symbol);
+        }
+
+        return symbol;
+    }
+}

ModernUO.Serialization.Generator/SourceGeneration/SymbolMetadata/SymbolMetadata.Builtin.cs

@@ -38,63 +38,63 @@ public static partial class SymbolMetadata
     {
         public bool IsGuid(Compilation compilation) =>
             symbol.Equals(
-                compilation.GetTypeByMetadataName(GUID_STRUCT),
+                compilation.GetCachedTypeByMetadataName(GUID_STRUCT),
                 SymbolEqualityComparer.Default
             );
 
         public bool IsTimeSpan(Compilation compilation) =>
             symbol.Equals(
-                compilation.GetTypeByMetadataName(TIMESPAN_STRUCT),
+                compilation.GetCachedTypeByMetadataName(TIMESPAN_STRUCT),
                 SymbolEqualityComparer.Default
             );
 
         public bool IsIpAddress(Compilation compilation) =>
             symbol.Equals(
-                compilation.GetTypeByMetadataName(IPADDRESS_CLASS),
+                compilation.GetCachedTypeByMetadataName(IPADDRESS_CLASS),
                 SymbolEqualityComparer.Default
             );
 
         public bool IsKeyValuePair(Compilation compilation) =>
             (symbol as INamedTypeSymbol)?.ConstructedFrom.Equals(
-                compilation.GetTypeByMetadataName(KEYVALUEPAIR_STRUCT),
+                compilation.GetCachedTypeByMetadataName(KEYVALUEPAIR_STRUCT),
                 SymbolEqualityComparer.Default
             ) == true;
 
         public bool IsDictionary(Compilation compilation) =>
             (symbol as INamedTypeSymbol)?.ConstructedFrom.Equals(
-                compilation.GetTypeByMetadataName(DICTIONARY_CLASS),
+                compilation.GetCachedTypeByMetadataName(DICTIONARY_CLASS),
                 SymbolEqualityComparer.Default
             ) == true;
 
         public bool IsDictionaryInterface(Compilation compilation) =>
-            (symbol as INamedTypeSymbol)?.ContainsInterface(compilation.GetTypeByMetadataName(DICTIONARY_INTERFACE)) ?? false;
+            (symbol as INamedTypeSymbol)?.ContainsInterface(compilation.GetCachedTypeByMetadataName(DICTIONARY_INTERFACE)) ?? false;
 
         public bool IsHashSet(Compilation compilation) =>
             (symbol as INamedTypeSymbol)?.ConstructedFrom.Equals(
-                compilation.GetTypeByMetadataName(HASHSET_CLASS),
+                compilation.GetCachedTypeByMetadataName(HASHSET_CLASS),
                 SymbolEqualityComparer.Default
             ) == true;
 
         public bool IsSortedSet(Compilation compilation) =>
             (symbol as INamedTypeSymbol)?.ConstructedFrom.Equals(
-                compilation.GetTypeByMetadataName(SORTEDSET_CLASS),
+                compilation.GetCachedTypeByMetadataName(SORTEDSET_CLASS),
                 SymbolEqualityComparer.Default
             ) == true;
 
         public bool IsSet(Compilation compilation) =>
-            (symbol as INamedTypeSymbol)?.ContainsInterface(compilation.GetTypeByMetadataName(SET_INTERFACE)) ?? false;
+            (symbol as INamedTypeSymbol)?.ContainsInterface(compilation.GetCachedTypeByMetadataName(SET_INTERFACE)) ?? false;
 
         public bool IsCollection(Compilation compilation) =>
-            (symbol as INamedTypeSymbol)?.ContainsInterface(compilation.GetTypeByMetadataName(COLLECTION_INTERFACE)) ?? false;
+            (symbol as INamedTypeSymbol)?.ContainsInterface(compilation.GetCachedTypeByMetadataName(COLLECTION_INTERFACE)) ?? false;
 
         public bool IsList(Compilation compilation) =>
             (symbol as INamedTypeSymbol)?.ConstructedFrom.Equals(
-                compilation.GetTypeByMetadataName(LIST_CLASS),
+                compilation.GetCachedTypeByMetadataName(LIST_CLASS),
                 SymbolEqualityComparer.Default
             ) == true;
 
         public bool IsListInterface(Compilation compilation) =>
-            (symbol as INamedTypeSymbol)?.ContainsInterface(compilation.GetTypeByMetadataName(LIST_INTERFACE)) ?? false;
+            (symbol as INamedTypeSymbol)?.ContainsInterface(compilation.GetCachedTypeByMetadataName(LIST_INTERFACE)) ?? false;
     }
 
     public static bool IsPrimitiveFromTypeDisplayString(string type) =>
@@ -103,7 +103,7 @@ type is "bool" or "sbyte" or "short" or "int" or "long" or "byte" or "ushort"
 
     public static bool IsType(this ISymbol symbol, Compilation compilation) =>
         (symbol as INamedTypeSymbol)?.ConstructedFrom.Equals(
-            compilation.GetTypeByMetadataName(TYPE_CLASS),
+            compilation.GetCachedTypeByMetadataName(TYPE_CLASS),
             SymbolEqualityComparer.Default
         ) == true;
 }