Shrink FrameType to be an Int16, as Int32 is completely unnecessary, and that memory space is about to become useful

src/Components/Components/src/RenderTree/RenderTreeBuilder.cs

@@ -5,7 +5,6 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Components;
 using Microsoft.AspNetCore.Components.Rendering;
 
 namespace Microsoft.AspNetCore.Components.RenderTree

src/Components/Components/src/RenderTree/RenderTreeFrame.cs

@@ -24,8 +24,8 @@ namespace Microsoft.AspNetCore.Components.RenderTree
         // Offset   Type
         // ------   ----
         // 0-3      Int32 (sequence number)
-        // 4-7      Int32 (frame type)
+        // 4-5      Int16 (frame type)
-        // 8-15     Value types (usage varies by frame type)
+        // 6-15     Value types (usage varies by frame type)
         // 16-23    Reference type (usage varies by frame type)
         // 24-31    Reference type (usage varies by frame type)
         // 32-39    Reference type (usage varies by frame type)

src/Components/Components/src/RenderTree/RenderTreeFrameType.cs

@@ -6,7 +6,7 @@ namespace Microsoft.AspNetCore.Components.RenderTree
     /// <summary>
     /// Describes the type of a <see cref="RenderTreeFrame"/>.
     /// </summary>
-    public enum RenderTreeFrameType: int
+    public enum RenderTreeFrameType: short
     {
         /// <summary>
         /// Used only for unintialized frames.

src/Components/Server/test/Circuits/RenderBatchWriterTest.cs

@@ -313,7 +313,7 @@ namespace Microsoft.AspNetCore.Components.Server
                 {
                     // Assume enums are represented as ints
                     var expectedEntry = expectedEntryIterationVar.GetType().IsEnum
-                        ? (int)expectedEntryIterationVar
+                        ? Convert.ToInt32(expectedEntryIterationVar)
                         : expectedEntryIterationVar;
 
                     if (expectedEntry is int expectedInt)

src/Components/Web.JS/src/Platform/Mono/MonoPlatform.ts

@@ -114,6 +114,10 @@ export const monoPlatform: Platform = {
     return (referenceTypedObject as any as number + 8) as any as Pointer;
   },
 
+  readInt16Field: function readHeapInt16(baseAddress: Pointer, fieldOffset?: number): number {
+    return Module.getValue((baseAddress as any as number) + (fieldOffset || 0), 'i16');
+  },
+
   readInt32Field: function readHeapInt32(baseAddress: Pointer, fieldOffset?: number): number {
     return Module.getValue((baseAddress as any as number) + (fieldOffset || 0), 'i32');
   },

src/Components/Web.JS/src/Platform/Platform.ts

@@ -14,6 +14,7 @@ export interface Platform {
   getArrayEntryPtr<TPtr extends Pointer>(array: System_Array<TPtr>, index: number, itemSize: number): TPtr;
 
   getObjectFieldsBaseAddress(referenceTypedObject: System_Object): Pointer;
+  readInt16Field(baseAddress: Pointer, fieldOffset?: number): number;
   readInt32Field(baseAddress: Pointer, fieldOffset?: number): number;
   readFloatField(baseAddress: Pointer, fieldOffset?: number): number;
   readObjectField<T extends System_Object>(baseAddress: Pointer, fieldOffset?: number): T;

src/Components/Web.JS/src/Rendering/RenderBatch/SharedMemoryRenderBatch.ts

@@ -99,7 +99,7 @@ const editReader = {
 // Keep in sync with memory layout in RenderTreeFrame.cs
 const frameReader = {
   structLength: 36,
-  frameType: (frame: RenderTreeFrame) => platform.readInt32Field(frame as any, 4) as FrameType,
+  frameType: (frame: RenderTreeFrame) => platform.readInt16Field(frame as any, 4) as FrameType,
   subtreeLength: (frame: RenderTreeFrame) => platform.readInt32Field(frame as any, 8),
   elementReferenceCaptureId: (frame: RenderTreeFrame) => platform.readStringField(frame as any, 16),
   componentId: (frame: RenderTreeFrame) => platform.readInt32Field(frame as any, 12),

src/Components/test/Ignitor.Test/RenderBatchReaderTest.cs

@@ -272,7 +272,7 @@ namespace Ignitor
                 {
                     // Assume enums are represented as ints
                     var expectedEntry = expectedEntryIterationVar.GetType().IsEnum
-                        ? (int)expectedEntryIterationVar
+                        ? Convert.ToInt32(expectedEntryIterationVar)
                         : expectedEntryIterationVar;
 
                     if (expectedEntry is int expectedInt)