Socket routing improvements, unit test cleanup (#276)

Updated WebSocket message routing improving performance for scenarios with multiple different subscriptions and topics
Added AddCommaSeparated helper for Enum value arrays to ParameterCollection
Improved EnumConverter performance and removed string allocation for happy path
Fixed CreateParamString extension method for ArrayParametersSerialization.Json
Fixed Shared GetOrderBookOptions and GetRecentTradeOptions base validations not being called

CryptoExchange.Net/Converters/SystemTextJson/EnumConverter.cs

@@ -82,14 +82,23 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
 #if NET8_0_OR_GREATER
         private static FrozenSet<EnumMapping>? _mappingToEnum = null;
         private static FrozenDictionary<T, string>? _mappingToString = null;
+
+        private static bool RunOptimistic => true;
 #else
         private static List<EnumMapping>? _mappingToEnum = null;
         private static Dictionary<T, string>? _mappingToString = null;
+        
+        // In NetStandard the `ValueTextEquals` method used is slower than just string comparing
+        // so only bother in newer frameworks
+        private static bool RunOptimistic => false;
 #endif
         private NullableEnumConverter? _nullableEnumConverter = null;
 
+        private static Type _enumType = typeof(T);
         private static T? _undefinedEnumValue;
+        private static bool _hasFlagsAttribute = _enumType.IsDefined(typeof(FlagsAttribute));
         private static ConcurrentBag<string> _unknownValuesWarned = new ConcurrentBag<string>();
+        private static ConcurrentBag<string> _notOptimalValuesWarned = new ConcurrentBag<string>();
 
         internal class NullableEnumConverter : JsonConverter<T?>
         {
@@ -153,10 +162,17 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
         private T? ReadNullable(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options, out bool isEmptyStringOrNull)
         {
             isEmptyStringOrNull = false;
-            var enumType = typeof(T);
             if (_mappingToEnum == null)
                 CreateMapping();
 
+            if (RunOptimistic)
+            {
+                var resultOptimistic = GetValueOptimistic(ref reader);
+                if (resultOptimistic != null)
+                    return resultOptimistic.Value;
+            }
+
+            var isNumber = reader.TokenType == JsonTokenType.Number;
             var stringValue = reader.TokenType switch
             {
                 JsonTokenType.String => reader.GetString(),
@@ -173,8 +189,9 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
                 return null;
             }
 
-            if (!GetValue(enumType, stringValue, out var result))
+            if (!GetValue(stringValue, out var result))
             {
+                // Note: checking this here and before the GetValue seems redundant but it allows enum mapping for empty strings
                 if (string.IsNullOrWhiteSpace(stringValue))
                 {
                     isEmptyStringOrNull = true;
@@ -185,13 +202,22 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
                     if (!_unknownValuesWarned.Contains(stringValue))
                     {
                         _unknownValuesWarned.Add(stringValue!);
-                        LibraryHelpers.StaticLogger?.LogWarning($"Cannot map enum value. EnumType: {enumType.FullName}, Value: {stringValue}, Known values: [{string.Join(", ", _mappingToEnum!.Select(m => $"{m.StringValue}: {m.Value}"))}]. If you think {stringValue} should added please open an issue on the Github repo");
+                        LibraryHelpers.StaticLogger?.LogWarning($"Cannot map enum value. EnumType: {_enumType.FullName}, Value: {stringValue}, Known values: [{string.Join(", ", _mappingToEnum!.Select(m => $"{m.StringValue}: {m.Value}"))}]. If you think {stringValue} should be added please open an issue on the Github repo");
                     }
                 }
 
                 return null;
             }
 
+            if (RunOptimistic && !isNumber)
+            {
+                if (!_notOptimalValuesWarned.Contains(stringValue))
+                {
+                    _notOptimalValuesWarned.Add(stringValue!);
+                    LibraryHelpers.StaticLogger?.LogTrace($"Enum mapping sub-optimal. EnumType: {_enumType.FullName}, Value: {stringValue}, Known values: [{string.Join(", ", _mappingToEnum!.Select(m => $"{m.StringValue}: {m.Value}"))}]");
+                }
+            }
+
             return result;
         }
 
@@ -202,18 +228,40 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
             writer.WriteStringValue(stringValue);
         }
 
-        private static bool GetValue(Type objectType, string value, out T? result)
+        /// <summary>
+        /// Try to get the enum value based on the string value using the Utf8JsonReader's ValueTextEquals method. 
+        /// This is an optimization to avoid string allocations when possible, but can only match case sensitively
+        /// </summary>
+        private static T? GetValueOptimistic(ref Utf8JsonReader reader)
+        {
+            if (reader.TokenType != JsonTokenType.String)
+                return null;
+
+            foreach (var item in _mappingToEnum!)
+            {
+                if (reader.ValueTextEquals(item.StringValue))
+                    return item.Value;
+            }
+
+            return null;
+        }
+
+        private static bool GetValue(string value, out T? result)
         {
             if (_mappingToEnum != null)
             {
                 EnumMapping? mapping = null;
-                // Try match on full equals
-                foreach (var item in _mappingToEnum)
+                // If we tried the optimistic path first we already know its not case match
+                if (!RunOptimistic) 
                 {
-                    if (item.StringValue.Equals(value, StringComparison.Ordinal))
+                    // Try match on full equals
+                    foreach (var item in _mappingToEnum)
                     {
-                        mapping = item;
-                        break;
+                        if (item.StringValue.Equals(value, StringComparison.Ordinal))
+                        {
+                            mapping = item;
+                            break;
+                        }
                     }
                 }
 
@@ -237,10 +285,10 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
                 }
             }
 
-            if (objectType.IsDefined(typeof(FlagsAttribute)))
+            if (_hasFlagsAttribute)
             {
                 var intValue = int.Parse(value);
-                result = (T)Enum.ToObject(objectType, intValue);
+                result = (T)Enum.ToObject(_enumType, intValue);
                 return true;
             }
 
@@ -262,8 +310,12 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
             try
             {
                 // If no explicit mapping is found try to parse string
-                result = (T)Enum.Parse(objectType, value, true);
-                if (!Enum.IsDefined(objectType, result))
+#if NET8_0_OR_GREATER
+                result = Enum.Parse<T>(value, true);
+#else
+                result = (T)Enum.Parse(_enumType, value, true);
+#endif
+                if (!Enum.IsDefined(_enumType, result))
                 {
                     result = default;
                     return false;
@@ -280,11 +332,12 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
 
         private static void CreateMapping()
         {
-            var mappingToEnum = new List<EnumMapping>();
-            var mappingToString = new Dictionary<T, string>();
+            var mappingStringToEnum = new List<EnumMapping>();
+            var mappingEnumToString = new Dictionary<T, string>();
 
-            var enumType = Nullable.GetUnderlyingType(typeof(T)) ?? typeof(T);
-            var enumMembers = enumType.GetFields();
+#pragma warning disable IL2080
+            var enumMembers = _enumType.GetFields();
+#pragma warning restore IL2080
             foreach (var member in enumMembers)
             {
                 var maps = member.GetCustomAttributes(typeof(MapAttribute), false);
@@ -292,23 +345,29 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
                 {
                     foreach (var value in attribute.Values)
                     {
-                        var enumVal = (T)Enum.Parse(enumType, member.Name);
-                        mappingToEnum.Add(new EnumMapping(enumVal, value));
-                        if (!mappingToString.ContainsKey(enumVal))
-                            mappingToString.Add(enumVal, value);
+#if NET8_0_OR_GREATER
+                        var enumVal = Enum.Parse<T>(member.Name);
+#else
+                        var enumVal = (T)Enum.Parse(_enumType, member.Name);
+#endif
+
+                        mappingStringToEnum.Add(new EnumMapping(enumVal, value));
+                        if (!mappingEnumToString.ContainsKey(enumVal))
+                            mappingEnumToString.Add(enumVal, value);
                     }
                 }
             }
 
 #if NET8_0_OR_GREATER
-            _mappingToEnum = mappingToEnum.ToFrozenSet();
-            _mappingToString = mappingToString.ToFrozenDictionary();
+            _mappingToEnum = mappingStringToEnum.ToFrozenSet();
+            _mappingToString = mappingEnumToString.ToFrozenDictionary();
 #else
-            _mappingToEnum = mappingToEnum;
-            _mappingToString = mappingToString;
+            _mappingToEnum = mappingStringToEnum;
+            _mappingToString = mappingEnumToString;
 #endif
         }
 
+        // For testing purposes only, allows resetting the static mapping and warnings
         internal static void Reset()
         {
             _undefinedEnumValue = null;
@@ -336,7 +395,6 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
         /// <returns></returns>
         public static T? ParseString(string value)
         {
-            var type = Nullable.GetUnderlyingType(typeof(T)) ?? typeof(T);
             if (_mappingToEnum == null)
                 CreateMapping();
 
@@ -369,8 +427,11 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
 
             try
             {
-                // If no explicit mapping is found try to parse string
-                return (T)Enum.Parse(type, value, true);
+#if NET8_0_OR_GREATER
+                return Enum.Parse<T>(value, true);
+#else
+                return (T)Enum.Parse(_enumType, value, true);
+#endif
             }
             catch (Exception)
             {

CryptoExchange.Net/Converters/SystemTextJson/ObjectStringConverter.cs

@@ -24,7 +24,7 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
             if (string.IsNullOrEmpty(value))
                 return default;
 
-            return (T?)JsonDocument.Parse(value!).Deserialize(typeof(T), options);
+            return JsonDocument.Parse(value!).Deserialize<T>(options);
         }
 
         /// <inheritdoc />