Optimize AddPropertyIfAbsent

src/Serilog/Capturing/DepthLimiter.cs

@@ -47,7 +47,7 @@ public LogEventPropertyValue CreatePropertyValue(object? value, Destructuring de
             return result;
         }
 
-        LogEventPropertyValue ILogEventPropertyValueFactory.CreatePropertyValue(object value, bool destructureObjects)
+        LogEventPropertyValue ILogEventPropertyValueFactory.CreatePropertyValue(object? value, bool destructureObjects)
         {
             var storedDepth = _currentDepth;
 

src/Serilog/Capturing/MessageTemplateProcessor.cs

@@ -14,7 +14,7 @@
 
 namespace Serilog.Capturing;
 
-class MessageTemplateProcessor : ILogEventPropertyFactory
+class MessageTemplateProcessor : ILogEventPropertyFactory, ILogEventPropertyValueFactory
 {
     readonly MessageTemplateCache _parser = new(new MessageTemplateParser());
     readonly PropertyBinder _propertyBinder;

src/Serilog/Core/Enrichers/PropertyEnricher.cs

@@ -28,7 +28,7 @@ public class PropertyEnricher : ILogEventEnricher
     /// </summary>
     /// <param name="name">The name of the property.</param>
     /// <param name="value">The value of the property.</param>
-    /// <param name="destructureObjects">If true, and the value is a non-primitive, non-array type,
+    /// <param name="destructureObjects">If <see langword="true"/>, and the value is a non-primitive, non-array type,
     /// then the value will be converted to a structure; otherwise, unknown types will
     /// be converted to scalars, which are generally stored as strings.</param>
     /// <exception cref="ArgumentNullException">When <paramref name="name"/> is <code>null</code></exception>
@@ -54,7 +54,6 @@ public void Enrich(LogEvent logEvent, ILogEventPropertyFactory propertyFactory)
         Guard.AgainstNull(logEvent);
         Guard.AgainstNull(propertyFactory);
 
-        var property = propertyFactory.CreateProperty(_name, _value, _destructureObjects);
-        logEvent.AddPropertyIfAbsent(property);
+        logEvent.AddPropertyIfAbsent(propertyFactory, _name, _value, _destructureObjects);
     }
 }

src/Serilog/Core/ILogEventPropertyValueFactory.cs

@@ -15,5 +15,5 @@ public interface ILogEventPropertyValueFactory
     /// then the value will be converted to a structure; otherwise, unknown types will
     /// be converted to scalars, which are generally stored as strings.</param>
     /// <returns>The value.</returns>
-    LogEventPropertyValue CreatePropertyValue(object value, bool destructureObjects = false);
+    LogEventPropertyValue CreatePropertyValue(object? value, bool destructureObjects = false);
 }

src/Serilog/Events/LogEvent.cs

@@ -1,4 +1,4 @@
-// Copyright 2013-2015 Serilog Contributors
+// Copyright 2013-2015 Serilog Contributors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -107,6 +107,8 @@ public string RenderMessage(IFormatProvider? formatProvider = null)
     /// </summary>
     public IReadOnlyDictionary<string, LogEventPropertyValue> Properties => _properties;
 
+    internal Dictionary<string, LogEventPropertyValue> PropertiesDictionary => _properties;
+
     /// <summary>
     /// An exception associated with the event, or null.
     /// </summary>
@@ -192,3 +194,18 @@ internal LogEvent Copy()
             properties);
     }
 }
+
+internal static class LogEventExtensions
+{
+    public static void AddPropertyIfAbsent(this LogEvent evt, ILogEventPropertyFactory factory, string name, object? value, bool destructureObjects = false)
+    {
+        if (!evt.Properties.ContainsKey(name))
+        {
+            evt.PropertiesDictionary.Add(
+                name,
+                factory is ILogEventPropertyValueFactory factory2
+                    ? factory2.CreatePropertyValue(value, destructureObjects)
+                    : factory.CreateProperty(name, value, destructureObjects).Value);
+        }
+    }
+}

src/Serilog/Log.cs

@@ -1190,7 +1190,7 @@ public static void Fatal(Exception? exception, string messageTemplate, params ob
     /// <param name="property">The resulting property.</param>
     /// <returns>True if the property could be bound, otherwise false (<summary>ILogger</summary>
     /// methods never throw exceptions).</returns>
-    public static bool BindProperty(string propertyName, object value, bool destructureObjects, [NotNullWhen(true)] out LogEventProperty? property)
+    public static bool BindProperty(string propertyName, object? value, bool destructureObjects, [NotNullWhen(true)] out LogEventProperty? property)
     {
         return Logger.BindProperty(propertyName, value, destructureObjects, out property);
     }

test/Serilog.ApprovalTests/Serilog.approved.txt

@@ -112,7 +112,7 @@ namespace Serilog.Core
     }
     public interface ILogEventPropertyValueFactory
     {
-        Serilog.Events.LogEventPropertyValue CreatePropertyValue(object value, bool destructureObjects = false);
+        Serilog.Events.LogEventPropertyValue CreatePropertyValue(object? value, bool destructureObjects = false);
     }
     public interface ILogEventSink
     {
@@ -629,7 +629,7 @@ namespace Serilog
         public static Serilog.ILogger Logger { get; set; }
         [Serilog.Core.MessageTemplateFormatMethod("messageTemplate")]
         public static bool BindMessageTemplate(string messageTemplate, object?[] propertyValues, [System.Diagnostics.CodeAnalysis.NotNullWhen(true)] out Serilog.Events.MessageTemplate? parsedTemplate, [System.Diagnostics.CodeAnalysis.NotNullWhen(true)] out System.Collections.Generic.IEnumerable<Serilog.Events.LogEventProperty>? boundProperties) { }
-        public static bool BindProperty(string propertyName, object value, bool destructureObjects, [System.Diagnostics.CodeAnalysis.NotNullWhen(true)] out Serilog.Events.LogEventProperty? property) { }
+        public static bool BindProperty(string propertyName, object? value, bool destructureObjects, [System.Diagnostics.CodeAnalysis.NotNullWhen(true)] out Serilog.Events.LogEventProperty? property) { }
         public static void CloseAndFlush() { }
         public static System.Threading.Tasks.ValueTask CloseAndFlushAsync() { }
         [Serilog.Core.MessageTemplateFormatMethod("messageTemplate")]

test/Serilog.PerformanceTests/LogContextEnrichmentBenchmark.cs

@@ -1,5 +1,6 @@
 namespace Serilog.PerformanceTests;
 
+[MemoryDiagnoser]
 public class LogContextEnrichmentBenchmark
 {
     ILogger _bare = null!, _enriched = null!;