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src/VisualStudio/Core/Next/FindSymbols/VisualStudioSymbolFinderEngineService.ServerCallback.cs

+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.FindSymbols;
+using Microsoft.CodeAnalysis.Remote.FindReferences;
+
+namespace Microsoft.VisualStudio.LanguageServices.Implementation.FindSymbols
+{
+    internal partial class VisualStudioSymbolFinderEngineService : ISymbolFinderEngineService
+    {
+        /// <summary>
+        /// Callback object we pass to the OOP server to hear about the result 
+        /// of the FindReferencesEngine as it executes there.
+        /// </summary>
+        private class ServerCallback
+        {
+            private readonly Solution _solution;
+            private readonly IStreamingFindReferencesProgress _progress;
+            private readonly CancellationToken _cancellationToken;
+
+            public ServerCallback(
+                Solution solution, 
+                IStreamingFindReferencesProgress progress,
+                CancellationToken cancellationToken)
+            {
+                _solution = solution;
+                _progress = progress;
+                _cancellationToken = cancellationToken;
+            }
+
+            public Task OnStartedAsync() => _progress.OnStartedAsync();
+            public Task OnCompletedAsync() => _progress.OnCompletedAsync();
+            public Task ReportProgressAsync(int current, int maximum) => _progress.ReportProgressAsync(current, maximum);
+
+            public Task OnFindInDocumentStartedAsync(SerializableDocumentId documentId)
+            {
+                var document = _solution.GetDocument(documentId.Rehydrate());
+                return _progress.OnFindInDocumentStartedAsync(document);
+            }
+
+            public Task OnFindInDocumentCompletedAsync(SerializableDocumentId documentId)
+            {
+                var document = _solution.GetDocument(documentId.Rehydrate());
+                return _progress.OnFindInDocumentCompletedAsync(document);
+            }
+
+            public async Task OnDefinitionFoundAsync(SerializableSymbolAndProjectId definition)
+            {
+                var symbolAndProjectId = await definition.RehydrateAsync(
+                    _solution, _cancellationToken).ConfigureAwait(false);
+                await _progress.OnDefinitionFoundAsync(symbolAndProjectId).ConfigureAwait(false);
+            }
+
+            public async Task OnReferenceFoundAsync(
+                SerializableSymbolAndProjectId definition, SerializableReferenceLocation reference)
+            {
+                var symbolAndProjectId = await definition.RehydrateAsync(
+                    _solution, _cancellationToken).ConfigureAwait(false);
+                var referenceLocation = await reference.RehydrateAsync(
+                    _solution, _cancellationToken).ConfigureAwait(false);
+
+                await _progress.OnReferenceFoundAsync(symbolAndProjectId, referenceLocation).ConfigureAwait(false);
+            }
+        }
+    }
+}
\ No newline at end of file

src/VisualStudio/Core/Next/FindSymbols/VisualStudioSymbolFinderEngineService.cs

@@ -17,7 +17,7 @@
 namespace Microsoft.VisualStudio.LanguageServices.Implementation.FindSymbols
 {
     [ExportWorkspaceService(typeof(ISymbolFinderEngineService), ServiceLayer.Host), Shared]
-    internal class VisualStudioSymbolFinderEngineService : ISymbolFinderEngineService
+    internal partial class VisualStudioSymbolFinderEngineService : ISymbolFinderEngineService
     {
         public async Task FindReferencesAsync(
             SymbolAndProjectId symbolAndProjectId, Solution solution, 
@@ -58,6 +58,9 @@ internal class VisualStudioSymbolFinderEngineService : ISymbolFinderEngineServic
                 return;
             }
 
+            // Create a callback that we can pass to the server process to hear about the 
+            // results as it finds them.  When we hear about results we'll forward them to
+            // the 'progress' parameter which will then upate the UI.
             var serverCallback = new ServerCallback(solution, progress, cancellationToken);
 
             using (var session = await client.CreateCodeAnalysisServiceSessionAsync(
@@ -69,56 +72,5 @@ internal class VisualStudioSymbolFinderEngineService : ISymbolFinderEngineServic
                     documents?.Select(SerializableDocumentId.Dehydrate).ToArray()).ConfigureAwait(false);
             }
         }
-
-        private class ServerCallback
-        {
-            private readonly Solution _solution;
-            private readonly IStreamingFindReferencesProgress _progress;
-            private readonly CancellationToken _cancellationToken;
-
-            public ServerCallback(
-                Solution solution, 
-                IStreamingFindReferencesProgress progress,
-                CancellationToken cancellationToken)
-            {
-                _solution = solution;
-                _progress = progress;
-                _cancellationToken = cancellationToken;
-            }
-
-            public Task OnStartedAsync() => _progress.OnStartedAsync();
-            public Task OnCompletedAsync() => _progress.OnCompletedAsync();
-            public Task ReportProgressAsync(int current, int maximum) => _progress.ReportProgressAsync(current, maximum);
-
-            public Task OnFindInDocumentStartedAsync(SerializableDocumentId documentId)
-            {
-                var document = _solution.GetDocument(documentId.Rehydrate());
-                return _progress.OnFindInDocumentStartedAsync(document);
-            }
-
-            public Task OnFindInDocumentCompletedAsync(SerializableDocumentId documentId)
-            {
-                var document = _solution.GetDocument(documentId.Rehydrate());
-                return _progress.OnFindInDocumentCompletedAsync(document);
-            }
-
-            public async Task OnDefinitionFoundAsync(SerializableSymbolAndProjectId definition)
-            {
-                var symbolAndProjectId = await definition.RehydrateAsync(
-                    _solution, _cancellationToken).ConfigureAwait(false);
-                await _progress.OnDefinitionFoundAsync(symbolAndProjectId).ConfigureAwait(false);
-            }
-
-            public async Task OnReferenceFoundAsync(
-                SerializableSymbolAndProjectId definition, SerializableReferenceLocation reference)
-            {
-                var symbolAndProjectId = await definition.RehydrateAsync(
-                    _solution, _cancellationToken).ConfigureAwait(false);
-                var referenceLocation = await reference.RehydrateAsync(
-                    _solution, _cancellationToken).ConfigureAwait(false);
-
-                await _progress.OnReferenceFoundAsync(symbolAndProjectId, referenceLocation).ConfigureAwait(false);
-            }
-        }
     }
 }
\ No newline at end of file

src/VisualStudio/Core/Next/ServicesVisualStudio.Next.csproj

@@ -124,6 +124,7 @@
       <DesignTime>True</DesignTime>
       <DependentUpon>ServicesVisualStudioNextResources.resx</DependentUpon>
     </Compile>
+    <Compile Include="FindSymbols\VisualStudioSymbolFinderEngineService.ServerCallback.cs" />
   </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Include="ServicesVisualStudioNextResources.resx">