support enum & set

Author: kerryjiang

src/SciSharp.MySQL.Replication/ColumnMetadata.cs

@@ -17,6 +17,11 @@ public class ColumnMetadata
             /// </summary>
             public ColumnType Type { get; set; }
 
+            /// <summary>
+            /// Gets or sets the underlying type of the column.
+            /// </summary>
+            public ColumnType? UnderlyingType { get; set; }
+
             /// <summary>
             /// Gets or sets the metadata value associated with the column.
             /// </summary>

src/SciSharp.MySQL.Replication/Events/EnumTypeTableMetadataInitializer.cs

@@ -26,8 +26,13 @@ private bool IsEnumColumn(ColumnMetadata columnMetadata)
             if (columnMetadata.Type != ColumnType.STRING)
                 return false;
 
-            // Len = 1 or 2
-            return (columnMetadata.MetadataValue & 0xFF) < 3;
+            var meta0 = columnMetadata.MetadataValue >> 8;
+            
+            if (meta0 != (int)ColumnType.ENUM)
+                return false;
+
+            columnMetadata.UnderlyingType = ColumnType.ENUM;
+            return true;
         }
     }
 }

src/SciSharp.MySQL.Replication/Events/RowsEvent.cs

@@ -232,10 +232,9 @@ protected object[] ReadRow(ref SequenceReader<byte> reader, TableMapEvent table,
                 if (nullColumns.Get(index))
                     continue;
 
-                var typeCode = columnTypes[i];
                 var columnMetadata = table.Metadata.Columns[i];
 
-                cells[index] = ReadCell(ref reader, (ColumnType)typeCode, columnMetadata);
+                cells[index] = ReadCell(ref reader, (ColumnType)(columnMetadata.UnderlyingType ?? columnMetadata.Type), columnMetadata);
             }
 
             return cells;

src/SciSharp.MySQL.Replication/Events/SetTypeTableMetadataInitializer.cs

@@ -11,12 +11,29 @@ public void InitializeMetadata(TableMetadata metadata)
 
             foreach (var column in metadata.Columns)
             {
-                if (column.Type != ColumnType.SET)
+                if (!IsSetColumn(column))
                     continue;
 
                 column.SetValues = metadata.SetStrValues[setColumnIndex];
                 setColumnIndex++;
             }
         }
+
+        private bool IsSetColumn(ColumnMetadata columnMetadata)
+        {
+            if (columnMetadata.Type == ColumnType.SET)
+                return true;
+
+            if (columnMetadata.Type != ColumnType.STRING)
+                return false;
+            
+            var meta0 = columnMetadata.MetadataValue >> 8;
+            
+            if (meta0 != (int)ColumnType.SET)
+                return false;
+
+            columnMetadata.UnderlyingType = ColumnType.SET;
+            return true;
+        }
     }
 }

src/SciSharp.MySQL.Replication/Events/TableMapEvent.cs

@@ -114,7 +114,7 @@ protected internal override void DecodeBody(ref SequenceReader<byte> reader, obj
 
             foreach (var columnMetadata in Metadata.Columns)
             {
-                var valueTypeIndex = (int)columnMetadata.Type;
+                var valueTypeIndex = (int) (columnMetadata.UnderlyingType ?? columnMetadata.Type);
 
                 if (valueTypeIndex < DataTypes.Length && DataTypes[valueTypeIndex] is IColumnMetadataLoader columnMetadataLoader)
                 {

src/SciSharp.MySQL.Replication/Types/StringType.cs

@@ -11,19 +11,16 @@ namespace SciSharp.MySQL.Replication.Types
     /// <remarks>
     /// Handles the reading and conversion of MySQL STRING values.
     /// </remarks>
-    class StringType : EnumType
+    class StringType : IMySQLDataType
     {
         /// <summary>
         /// Reads a STRING value from the binary log.
         /// </summary>
         /// <param name="reader">The sequence reader containing the bytes to read.</param>
         /// <param name="columnMetadata">Metadata for the column.</param>
         /// <returns>A string representing the MySQL STRING value.</returns>
-        public override object ReadValue(ref SequenceReader<byte> reader, ColumnMetadata columnMetadata)
+        public object ReadValue(ref SequenceReader<byte> reader, ColumnMetadata columnMetadata)
         {
-            if (columnMetadata.MaxLength < 3)
-                return base.ReadValue(ref reader, columnMetadata);
-            
             return reader.ReadLengthEncodedString();
         }
     }