Add schema cache

CHANGELOG.md

@@ -11,6 +11,7 @@
   * `list.Filter(query, arguments)` will filter the list and return the filtered collection. It is roughly equivalent to `list.AsRealmQueryable().Filter(query, arguments)`.
 
   The resulting queryable collection will behave identically to the results obtained by calling `realm.All<T>()`, i.e. it will emit notifications when it changes and automatically update itself. (Issue [#1499](https://github.com/realm/realm-dotnet/issues/1499))
+* Added a cache for the Realm schema. This will speed up `Realm.GetInstance` invocations where `RealmConfiguration.ObjectClasses` is explicitly set. The speed gains will depend on the number and complexity of your model classes. A reference benchmark that tests a schema containing all valid Realm property types showed a 25% speed increase of Realm.GetInstance. (Issue [#2194](https://github.com/realm/realm-dotnet/issues/2194))
 
 ### Compatibility
 * Realm Studio: 11.0.0 or later.

Realm/Realm/Schema/ObjectSchema.cs

@@ -33,6 +33,8 @@ namespace Realms.Schema
     [DebuggerDisplay("Name = {Name}, Properties = {Count}")]
     public class ObjectSchema : IReadOnlyCollection<Property>
     {
+        private static readonly IDictionary<TypeInfo, ObjectSchema> _cache = new Dictionary<TypeInfo, ObjectSchema>();
+
         private readonly ReadOnlyDictionary<string, Property> _properties;
 
         /// <summary>
@@ -109,6 +111,10 @@ private ObjectSchema(string name, IDictionary<string, Property> properties)
         public static ObjectSchema FromType(TypeInfo type)
         {
             Argument.NotNull(type, nameof(type));
+            if (_cache.TryGetValue(type, out var result))
+            {
+                return result;
+            }
 
             Argument.Ensure(type.IsRealmObject() || type.IsEmbeddedObject(), $"The class {type.FullName} must descend directly from RealmObject", nameof(type));
 
@@ -148,9 +154,10 @@ public static ObjectSchema FromType(TypeInfo type)
                 builder.Add(schemaProperty);
             }
 
-            var ret = builder.Build();
-            ret.Type = type;
-            return ret;
+            result = builder.Build();
+            result.Type = type;
+            _cache[type] = result;
+            return result;
         }
 
         internal class Builder : List<Property>

Tests/Benchmarks/PerformanceTests/README.md

@@ -4,7 +4,7 @@ The Realm .NET SDK uses [Benchmark.NET](http://benchmarkdotnet.org) to run synth
 
 ## Running the benchmarks
 
-To run all tests, use `dotnet run -c Release -f net5.0 -- -f *`. To run only a subset of the tests, replace `*` with a regex that will match the tests you want to run. To list all benchmarks, use `dotnet run -c Release -f net5.0 -- --list`. Refere to [the docs](https://benchmarkdotnet.org/articles/guides/console-args.html) for a complete list of the supported arguments.
+To run all tests, use `dotnet run -c Release -f net5.0 -- -f *`. To run only a subset of the tests, replace `*` with a regex that will match the tests you want to run. To list all benchmarks, use `dotnet run -c Release -f net5.0 -- --list`. Refer to [the docs](https://benchmarkdotnet.org/articles/guides/console-args.html) for a complete list of the supported arguments.
 
 ## Best practices