Merge pull request #14044 from heejaechang/reduceallocation1

removed allocation caused by concurrent dictionary

src/Workspaces/Core/Portable/Execution/ChecksumTreeCollection.TreeNodes.cs

@@ -140,10 +140,11 @@ public SubTreeNode(ChecksumTreeCollection owner, Serializer serializer)
             public virtual ChecksumObject TryGetChecksumObject(Checksum checksum, CancellationToken cancellationToken)
             {
                 ChecksumObject checksumObject;
-                foreach (var entry in _cache.Values)
+                foreach (var kv in _cache)
                 {
                     cancellationToken.ThrowIfCancellationRequested();
 
+                    var entry = kv.Value;
                     if (entry.TryGetValue(checksum, out checksumObject))
                     {
                         // this cache has information for the checksum
@@ -177,8 +178,9 @@ public virtual void AppendChecksumObjects(Dictionary<Checksum, ChecksumObject> m
                     return;
                 }
 
-                foreach (var entry in _cache.Values)
+                foreach (var kv in _cache)
                 {
+                    var entry = kv.Value;
                     AppendChecksumObjects(map, searchingChecksumsLeft, entry, cancellationToken);
                     if (searchingChecksumsLeft.Count == 0)
                     {
@@ -215,8 +217,9 @@ public ChecksumObjectCache TryGetChecksumObjectEntry(object key, string kind, Ca
                     return self;
                 }
 
-                foreach (var entry in _cache.Values)
+                foreach (var kv in _cache)
                 {
+                    var entry = kv.Value;
                     var tree = entry.TryGetSubTreeNode();
                     if (tree == null)
                     {

src/Workspaces/Core/Portable/Execution/ChecksumTreeCollection.cs

@@ -74,8 +74,9 @@ public IRootChecksumTreeNode CreateRootTreeNode(SolutionState solutionState)
         public ChecksumObject GetChecksumObject(Checksum checksum, CancellationToken cancellationToken)
         {
             // search snapshots we have
-            foreach (var cache in _rootTreeNodes.Values)
+            foreach (var kv in _rootTreeNodes)
             {
+                var cache = kv.Value;
                 var checksumObject = cache.TryGetChecksumObject(checksum, cancellationToken);
                 if (checksumObject != null)
                 {
@@ -84,10 +85,11 @@ public ChecksumObject GetChecksumObject(Checksum checksum, CancellationToken can
             }
 
             // search global assets
-            foreach (var asset in _globalAssets.Values)
+            foreach (var kv in _globalAssets)
             {
                 cancellationToken.ThrowIfCancellationRequested();
 
+                var asset = kv.Value;
                 if (asset.Checksum == checksum)
                 {
                     return asset;
@@ -106,8 +108,9 @@ public ChecksumObject GetChecksumObject(Checksum checksum, CancellationToken can
                 var result = new Dictionary<Checksum, ChecksumObject>();
 
                 // search checksum trees we have
-                foreach (var cache in _rootTreeNodes.Values)
+                foreach (var kv in _rootTreeNodes)
                 {
+                    var cache = kv.Value;
                     cache.AppendChecksumObjects(result, searchingChecksumsLeft.Object, cancellationToken);
                     if (result.Count == numberOfChecksumsToSearch)
                     {
@@ -118,10 +121,11 @@ public ChecksumObject GetChecksumObject(Checksum checksum, CancellationToken can
                 }
 
                 // search global assets
-                foreach (var asset in _globalAssets.Values)
+                foreach (var kv in _globalAssets)
                 {
                     cancellationToken.ThrowIfCancellationRequested();
 
+                    var asset = kv.Value;
                     if (searchingChecksumsLeft.Object.Remove(asset.Checksum))
                     {
                         result[asset.Checksum] = asset;
@@ -142,8 +146,9 @@ public ChecksumObject GetChecksumObject(Checksum checksum, CancellationToken can
 
         private ChecksumObjectCache TryGetChecksumObjectEntry(object key, string kind, CancellationToken cancellationToken)
         {
-            foreach (var cache in _rootTreeNodes.Values)
+            foreach (var kv in _rootTreeNodes)
             {
+                var cache = kv.Value;
                 var entry = cache.TryGetChecksumObjectEntry(key, kind, cancellationToken);
                 if (entry != null)
                 {