Pre-encode property names of the JSON (#93)

Author: alexaka1

.changeset/grumpy-paws-vanish.md

@@ -0,0 +1,5 @@
+---
+"alexaka1.serilog.extensions.formatting": patch
+---
+
+Small performance increase by pre-encoding the default property names, to be able to write them to stream as-is.

src/Serilog.Extensions.Formatting/JsonLogPropertyNames.cs

@@ -6,19 +6,19 @@ internal readonly struct JsonLogPropertyNames
     {
         public JsonLogPropertyNames(JsonNamingPolicy namingPolicy)
         {
-            Timestamp = namingPolicy.ConvertName(TimestampPropertyName);
-            Level = namingPolicy.ConvertName(LevelPropertyName);
-            MessageTemplate = namingPolicy.ConvertName(MessageTemplatePropertyName);
-            RenderedMessage = namingPolicy.ConvertName(RenderedMessagePropertyName);
-            TraceId = namingPolicy.ConvertName(TraceIdPropertyName);
-            SpanId = namingPolicy.ConvertName(SpanIdPropertyName);
-            Exception = namingPolicy.ConvertName(ExceptionPropertyName);
-            Properties = namingPolicy.ConvertName(PropertiesPropertyName);
-            Renderings = namingPolicy.ConvertName(RenderingsPropertyName);
-            Null = namingPolicy.ConvertName(NullPropertyName);
-            TypeTag = namingPolicy.ConvertName(TypeTagPropertyName);
-            Format = namingPolicy.ConvertName(FormatPropertyName);
-            Rendering = namingPolicy.ConvertName(RenderingPropertyName);
+            Timestamp = JsonEncodedText.Encode(namingPolicy.ConvertName(TimestampPropertyName));
+            Level = JsonEncodedText.Encode(namingPolicy.ConvertName(LevelPropertyName));
+            MessageTemplate = JsonEncodedText.Encode(namingPolicy.ConvertName(MessageTemplatePropertyName));
+            RenderedMessage = JsonEncodedText.Encode(namingPolicy.ConvertName(RenderedMessagePropertyName));
+            TraceId = JsonEncodedText.Encode(namingPolicy.ConvertName(TraceIdPropertyName));
+            SpanId = JsonEncodedText.Encode(namingPolicy.ConvertName(SpanIdPropertyName));
+            Exception = JsonEncodedText.Encode(namingPolicy.ConvertName(ExceptionPropertyName));
+            Properties = JsonEncodedText.Encode(namingPolicy.ConvertName(PropertiesPropertyName));
+            Renderings = JsonEncodedText.Encode(namingPolicy.ConvertName(RenderingsPropertyName));
+            Null = JsonEncodedText.Encode(namingPolicy.ConvertName(NullPropertyName));
+            TypeTag = JsonEncodedText.Encode(namingPolicy.ConvertName(TypeTagPropertyName));
+            Format = JsonEncodedText.Encode(namingPolicy.ConvertName(FormatPropertyName));
+            Rendering = JsonEncodedText.Encode(namingPolicy.ConvertName(RenderingPropertyName));
         }
 
         private const string TimestampPropertyName = "Timestamp";
@@ -35,18 +35,18 @@ public JsonLogPropertyNames(JsonNamingPolicy namingPolicy)
         private const string FormatPropertyName = "Format";
         private const string RenderingPropertyName = "Rendering";
 
-        public string Timestamp { get; }
-        public string Level { get; }
-        public string MessageTemplate { get; }
-        public string RenderedMessage { get; }
-        public string TraceId { get; }
-        public string SpanId { get; }
-        public string Exception { get; }
-        public string Properties { get; }
-        public string Renderings { get; }
-        public string Null { get; }
-        public string TypeTag { get; }
-        public string Format { get; }
-        public string Rendering { get; }
+        public JsonEncodedText Timestamp { get; }
+        public JsonEncodedText Level { get; }
+        public JsonEncodedText MessageTemplate { get; }
+        public JsonEncodedText RenderedMessage { get; }
+        public JsonEncodedText TraceId { get; }
+        public JsonEncodedText SpanId { get; }
+        public JsonEncodedText Exception { get; }
+        public JsonEncodedText Properties { get; }
+        public JsonEncodedText Renderings { get; }
+        public JsonEncodedText Null { get; }
+        public JsonEncodedText TypeTag { get; }
+        public JsonEncodedText Format { get; }
+        public JsonEncodedText Rendering { get; }
     }
 }

src/Serilog.Extensions.Formatting/Utf8JsonFormatter.cs

@@ -233,7 +233,15 @@ private void VisitDictionaryValue(DictionaryValue dictionary, Utf8JsonWriter wri
             foreach (var element in dictionary.Elements)
             {
                 string key = element.Key.Value?.ToString();
-                writer.WritePropertyName(key != null ? _namingPolicy.ConvertName(key) : _names.Null);
+                if (key != null)
+                {
+                    writer.WritePropertyName(_namingPolicy.ConvertName(key));
+                }
+                else
+                {
+                    writer.WritePropertyName(_names.Null);
+                }
+
                 Format(element.Value, writer);
             }