Updated template parsing logic into it's own method

Author: jschick04

src/EventLogExpert.Eventing.Tests/Helpers/EventMethodsTests.cs

@@ -202,17 +202,18 @@ public void ConvertVariant_WhenHexInt64_ShouldReturnUInt64()
     }
 
     [Fact]
-    public void ConvertVariant_WhenInt16_ShouldReturnByte()
+    public void ConvertVariant_WhenInt16_ShouldReturnShort()
     {
         // Arrange
-        byte expectedValue = 100;
+        short expectedValue = -1234;
         var variant = CreateVariant(EvtVariantType.Int16, expectedValue);
 
         // Act
         var result = EventMethods.ConvertVariant(variant);
 
         // Assert
         Assert.NotNull(result);
+        Assert.IsType<short>(result);
         Assert.Equal(expectedValue, result);
     }
 
@@ -258,8 +259,8 @@ public void ConvertVariant_WhenInvalidType_ShouldThrowInvalidDataException()
         var exception = Assert.Throws<InvalidDataException>(
             () => EventMethods.ConvertVariant(variant));
 
-        Assert.Contains("Invalid", exception.Message);
         Assert.Contains(nameof(EvtVariantType), exception.Message);
+        Assert.Contains("9999", exception.Message);
     }
 
     [Fact]
@@ -674,9 +675,11 @@ private static EvtVariant CreateVariantWithCount(EvtVariantType type, object? va
                         break;
                     case EvtVariantType.SByte:
                     case EvtVariantType.Byte:
-                    case EvtVariantType.Int16:
                         *(byte*)buffer = (byte)value;
                         break;
+                    case EvtVariantType.Int16:
+                        *(short*)buffer = (short)value;
+                        break;
                     case EvtVariantType.UInt16:
                         *(ushort*)buffer = (ushort)value;
                         break;

src/EventLogExpert.Eventing/EventResolvers/EventResolverBase.cs

@@ -199,33 +199,7 @@ private static bool DoesTemplateMatchPropertyCount(ReadOnlySpan<char> template,
     {
         if (template.IsEmpty) { return false; }
 
-        var cache = s_formattedPropertiesCache.GetAlternateLookup<ReadOnlySpan<char>>();
-
-        if (cache.TryGetValue(template, out string[]? dataNodes))
-        {
-            return dataNodes.Length == eventPropertyCount;
-        }
-
-        List<string> temp = [];
-        ReadOnlySpan<char> outTypeAttribute = "outType=\"";
-
-        foreach (var line in template.EnumerateLines())
-        {
-            int templateIndex = line.IndexOf(outTypeAttribute, StringComparison.Ordinal);
-
-            if (templateIndex == -1) { continue; }
-
-            templateIndex += outTypeAttribute.Length;
-            int endIndex = line[templateIndex..].IndexOf('"');
-
-            if (endIndex != -1)
-            {
-                temp.Add(new string(line.Slice(templateIndex, endIndex)));
-            }
-        }
-
-        dataNodes = [.. temp];
-        cache.TryAdd(template, dataNodes);
+        string[] dataNodes = GetOrParseTemplateDataNodes(template);
 
         return dataNodes.Length == 0 || dataNodes.Length == eventPropertyCount;
     }
@@ -235,30 +209,9 @@ private static List<string> GetFormattedProperties(ReadOnlySpan<char> template,
         string[]? dataNodes = null;
         List<string> providers = [];
 
-        var cache = s_formattedPropertiesCache.GetAlternateLookup<ReadOnlySpan<char>>();
-
-        if (!template.IsEmpty && !cache.TryGetValue(template, out dataNodes))
+        if (!template.IsEmpty)
         {
-            List<string> temp = [];
-            ReadOnlySpan<char> outTypeAttribute = "outType=\"";
-
-            foreach (var line in template.EnumerateLines())
-            {
-                int templateIndex = line.IndexOf(outTypeAttribute, StringComparison.Ordinal);
-
-                if (templateIndex == -1) { continue; }
-
-                templateIndex += outTypeAttribute.Length;
-                int endIndex = line[templateIndex..].IndexOf('"');
-
-                if (endIndex != -1)
-                {
-                    temp.Add(new string(line.Slice(templateIndex, endIndex)));
-                }
-            }
-
-            dataNodes = [.. temp];
-            cache.TryAdd(template, dataNodes);
+            dataNodes = GetOrParseTemplateDataNodes(template);
         }
 
         int index = 0;
@@ -308,6 +261,67 @@ private static List<string> GetFormattedProperties(ReadOnlySpan<char> template,
         return providers;
     }
 
+    private static string[] GetOrParseTemplateDataNodes(ReadOnlySpan<char> template)
+    {
+        var cache = s_formattedPropertiesCache.GetAlternateLookup<ReadOnlySpan<char>>();
+
+        if (cache.TryGetValue(template, out string[]? dataNodes))
+        {
+            return dataNodes;
+        }
+
+        List<string> temp = [];
+        ReadOnlySpan<char> dataElement = "<data ";
+        ReadOnlySpan<char> outTypeAttribute = "outType=\"";
+
+        int searchStart = 0;
+
+        while (searchStart < template.Length)
+        {
+            int dataIndex = template[searchStart..].IndexOf(dataElement, StringComparison.OrdinalIgnoreCase);
+
+            if (dataIndex == -1) { break; }
+
+            dataIndex += searchStart;
+
+            // Find the end of this element
+            int elementEnd = template[dataIndex..].IndexOf("/>");
+
+            if (elementEnd == -1)
+            {
+                elementEnd = template[dataIndex..].IndexOf('>');
+            }
+
+            if (elementEnd == -1) { break; }
+
+            elementEnd += dataIndex;
+
+            ReadOnlySpan<char> element = template[dataIndex..elementEnd];
+            int outTypeIndex = element.IndexOf(outTypeAttribute, StringComparison.Ordinal);
+
+            if (outTypeIndex != -1)
+            {
+                outTypeIndex += outTypeAttribute.Length;
+                int endIndex = element[outTypeIndex..].IndexOf('"');
+
+                temp.Add(endIndex != -1 ?
+                    new string(element.Slice(outTypeIndex, endIndex)) :
+                    string.Empty);
+            }
+            else
+            {
+                temp.Add(string.Empty);
+            }
+
+            searchStart = elementEnd + 1;
+        }
+
+        dataNodes = [.. temp];
+        cache.TryAdd(template, dataNodes);
+
+        return dataNodes;
+    }
+
     private static void ResizeBuffer(ref char[] buffer, ref Span<char> source, int sizeToAdd)
     {
         char[] newBuffer = ArrayPool<char>.Shared.Rent(source.Length + sizeToAdd);

src/EventLogExpert.Eventing/Helpers/EventMethods.cs

@@ -266,7 +266,7 @@ internal static partial class EventMethods
 
                 return stringArray;
             default:
-                return $"[Unknown EvtVariantType: {variant.Type}]";
+                throw new InvalidDataException($"Invalid {nameof(EvtVariantType)}: {variant.Type}");
         }
     }