Make enum a single byte

src/VisualStudio/Core/Test.Next/Remote/SerializationValidator.cs

@@ -55,10 +55,10 @@ internal sealed class ChecksumObjectCollection<T> : IEnumerable<T>
             /// </summary>
             public readonly Checksum Checksum;
 
-            public ChecksumObjectCollection(SerializationValidator validator, ChecksumCollection collection)
+            public ChecksumObjectCollection(SerializationValidator validator, WellKnownSynchronizationKind kind, ChecksumCollection collection)
             {
                 Checksum = collection.Checksum;
-                Kind = collection.GetWellKnownSynchronizationKind();
+                Kind = kind;
 
                 // using .Result here since we don't want to convert all calls to this to async.
                 // and none of ChecksumWithChildren actually use async
@@ -120,7 +120,7 @@ public async Task<Solution> GetSolutionAsync(SolutionAssetStorage.Scope scope)
         }
 
         public ChecksumObjectCollection<ProjectStateChecksums> ToProjectObjects(ChecksumCollection collection)
-            => new(this, collection);
+            => new(this, WellKnownSynchronizationKind.ProjectState, collection);
 
         internal async Task VerifyAssetAsync(SolutionStateChecksums solutionObject)
         {

src/Workspaces/Core/Portable/Remote/WellKnownSynchronizationKind.cs

@@ -4,30 +4,28 @@
 
 namespace Microsoft.CodeAnalysis.Serialization;
 
-internal enum WellKnownSynchronizationKind
+internal enum WellKnownSynchronizationKind : byte
 {
     // Start at a different value from 0 so that if we ever get 0 we know it's a bug.
 
     // Solution snapshot state, including generator info (like frozen generated documents).
     SolutionCompilationState = 1,
 
     // Solution snapshot state, only referencing actual user (non-generated) documents, options, and references.
-    SolutionState,
-    ProjectState,
-
-    ChecksumCollection,
-
-    SolutionAttributes,
-    ProjectAttributes,
-    DocumentAttributes,
-    SourceGeneratedDocumentIdentity,
-    SourceGeneratorExecutionVersionMap,
-
-    CompilationOptions,
-    ParseOptions,
-    ProjectReference,
-    MetadataReference,
-    AnalyzerReference,
-
-    SerializableSourceText,
+    SolutionState = 2,
+    ProjectState = 3,
+
+    SolutionAttributes = 4,
+    ProjectAttributes = 5,
+    DocumentAttributes = 6,
+    SourceGeneratedDocumentIdentity = 7,
+    SourceGeneratorExecutionVersionMap = 8,
+
+    CompilationOptions = 9,
+    ParseOptions = 10,
+    ProjectReference = 11,
+    MetadataReference = 12,
+    AnalyzerReference = 13,
+
+    SerializableSourceText = 14,
 }

src/Workspaces/Core/Portable/Serialization/SerializationExtensions.cs

@@ -18,7 +18,6 @@ public static WellKnownSynchronizationKind GetWellKnownSynchronizationKind(this
             SolutionCompilationStateChecksums => WellKnownSynchronizationKind.SolutionCompilationState,
             SolutionStateChecksums => WellKnownSynchronizationKind.SolutionState,
             ProjectStateChecksums => WellKnownSynchronizationKind.ProjectState,
-            ChecksumCollection => WellKnownSynchronizationKind.ChecksumCollection,
             SolutionInfo.SolutionAttributes => WellKnownSynchronizationKind.SolutionAttributes,
             ProjectInfo.ProjectAttributes => WellKnownSynchronizationKind.ProjectAttributes,
             DocumentInfo.DocumentAttributes => WellKnownSynchronizationKind.DocumentAttributes,

src/Workspaces/Core/Portable/Serialization/SerializerService.cs

@@ -157,10 +157,6 @@ public void Serialize(object value, ObjectWriter writer, SolutionReplicationCont
                     ((ProjectStateChecksums)value).Serialize(writer);
                     return;
 
-                case WellKnownSynchronizationKind.ChecksumCollection:
-                    ((ChecksumCollection)value).WriteTo(writer);
-                    return;
-
                 case WellKnownSynchronizationKind.SourceGeneratorExecutionVersionMap:
                     ((SourceGeneratorExecutionVersionMap)value).WriteTo(writer);
                     return;
@@ -184,7 +180,6 @@ public object Deserialize(WellKnownSynchronizationKind kind, ObjectReader reader
                 WellKnownSynchronizationKind.SolutionCompilationState => SolutionCompilationStateChecksums.Deserialize(reader),
                 WellKnownSynchronizationKind.SolutionState => SolutionStateChecksums.Deserialize(reader),
                 WellKnownSynchronizationKind.ProjectState => ProjectStateChecksums.Deserialize(reader),
-                WellKnownSynchronizationKind.ChecksumCollection => ChecksumCollection.ReadFrom(reader),
                 WellKnownSynchronizationKind.SolutionAttributes => SolutionInfo.SolutionAttributes.ReadFrom(reader),
                 WellKnownSynchronizationKind.ProjectAttributes => ProjectInfo.ProjectAttributes.ReadFrom(reader),
                 WellKnownSynchronizationKind.DocumentAttributes => DocumentInfo.DocumentAttributes.ReadFrom(reader),

src/Workspaces/Remote/Core/RemoteHostAssetSerialization.cs

@@ -45,7 +45,7 @@ public static async ValueTask WriteDataAsync(
 
                 var kind = asset.GetWellKnownSynchronizationKind();
                 checksum.WriteTo(writer);
-                writer.WriteInt32((int)kind);
+                writer.WriteByte((byte)kind);
                 serializer.Serialize(asset, writer, context, cancellationToken);
 
                 // We flush after each item as that forms a reasonably sized chunk of data to want to then send over the
@@ -89,7 +89,7 @@ public static void ReadData<T, TArg>(
             for (int i = 0, n = objectCount; i < n; i++)
             {
                 var checksum = Checksum.ReadFrom(reader);
-                var kind = (WellKnownSynchronizationKind)reader.ReadInt32();
+                var kind = (WellKnownSynchronizationKind)reader.ReadByte();
 
                 // in service hub, cancellation means simply closed stream
                 var result = serializerService.Deserialize(kind, reader, cancellationToken);