reduce some string alloc on building (#4564)

AzureAD · Jan 24, 2024 · 16827a2 · 16827a2
1 parent 4a0e782
commit 16827a2
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Showing 2 changed files with 25 additions and 16 deletions.
diff --git a/src/client/Microsoft.Identity.Client/OAuth2/Throttling/ThrottleCommon.cs b/src/client/Microsoft.Identity.Client/OAuth2/Throttling/ThrottleCommon.cs
@@ -13,7 +13,7 @@ internal static class ThrottleCommon
         public const string ThrottleRetryAfterHeaderName = "x-ms-lib-capability";
         public const string ThrottleRetryAfterHeaderValue = "retry-after, h429";
 
-        internal const string KeyDelimiter = ".";
+        internal const char KeyDelimiter = '.';
 
         /// <summary>
         /// The strict thumbprint is based on: 
@@ -28,18 +28,22 @@ public static string GetRequestStrictThumbprint(
             string authority,
             string homeAccountId)
         {
-            StringBuilder sb = new StringBuilder();
+            var sb = new StringBuilder();
             if (bodyParams.TryGetValue(OAuth2Parameter.ClientId, out string clientId))
             {
-                sb.Append((clientId ?? "") + KeyDelimiter);
+                sb.Append(clientId);
+                sb.Append(KeyDelimiter);
             }
-            sb.Append(authority + KeyDelimiter);
+            sb.Append(authority);
+            sb.Append(KeyDelimiter);
             if (bodyParams.TryGetValue(OAuth2Parameter.Scope, out string scopes))
             {
-                sb.Append((scopes ?? "") + KeyDelimiter);
+                sb.Append(scopes);
+                sb.Append(KeyDelimiter);
             }
 
-            sb.Append((homeAccountId ?? "") + KeyDelimiter);
+            sb.Append(homeAccountId);
+            sb.Append(KeyDelimiter);
 
             return sb.ToString();
         }

diff --git a/src/client/Microsoft.Identity.Client/OAuth2/Throttling/UiRequiredProvider.cs b/src/client/Microsoft.Identity.Client/OAuth2/Throttling/UiRequiredProvider.cs
@@ -74,7 +74,7 @@ private void TryThrowException(string thumbprint, ILoggerAdapter logger)
                     $"[Throttling] Exception thrown because of throttling rule UiRequired - thumbprint: {thumbprint}",
                     $"[Throttling] Exception thrown because of throttling rule UiRequired ");
 
-                // mark the exception for logging purposes                
+                // mark the exception for logging purposes
                 throw new MsalThrottledUiRequiredException(uiException);
             }
         }
@@ -85,7 +85,7 @@ private void TryThrowException(string thumbprint, ILoggerAdapter logger)
         /// Currently, throttling will only apply to public client applications at first. 
         /// </summary>
         private static bool IsRequestSupported(AuthenticationRequestParameters requestParams)
-        {            
+        {
             return !requestParams.AppConfig.IsConfidentialClient &&
                 requestParams.ApiId == TelemetryCore.Internal.Events.ApiEvent.ApiIds.AcquireTokenSilent;
         }
@@ -102,29 +102,34 @@ private static string GetRequestStrictThumbprint(
             string authority,
             ICryptographyManager crypto)
         {
-            StringBuilder sb = new StringBuilder();
+            var sb = new StringBuilder();
             if (bodyParams.TryGetValue(OAuth2Parameter.ClientId, out string clientId))
             {
-                sb.Append((clientId ?? "") + ThrottleCommon.KeyDelimiter);
+                sb.Append(clientId);
+                sb.Append(ThrottleCommon.KeyDelimiter);
             }
-            sb.Append(authority + ThrottleCommon.KeyDelimiter);
+            sb.Append(authority);
+            sb.Append(ThrottleCommon.KeyDelimiter);
             if (bodyParams.TryGetValue(OAuth2Parameter.Scope, out string scopes))
             {
-                sb.Append((scopes ?? "") + ThrottleCommon.KeyDelimiter);
+                sb.Append(scopes);
+                sb.Append(ThrottleCommon.KeyDelimiter);
             }
 
-            if (bodyParams.TryGetValue(OAuth2Parameter.RefreshToken, out string rt) && 
+            if (bodyParams.TryGetValue(OAuth2Parameter.RefreshToken, out string rt) &&
                 !string.IsNullOrEmpty(rt))
             {
-                sb.Append(crypto.CreateSha256Hash(rt) + ThrottleCommon.KeyDelimiter);
+                sb.Append(crypto.CreateSha256Hash(rt));
+                sb.Append(ThrottleCommon.KeyDelimiter);
             }
 
             // check mam enrollment id
             if (bodyParams.TryGetValue(SilentRequestHelper.MamEnrollmentIdKey, out string mamEnrollmentId))
             {
-                sb.Append(crypto.CreateSha256Hash(mamEnrollmentId) + ThrottleCommon.KeyDelimiter);
+                sb.Append(crypto.CreateSha256Hash(mamEnrollmentId));
+                sb.Append(ThrottleCommon.KeyDelimiter);
             }
-            
+
             return sb.ToString();
         }
     }