Consolidated the key value naming restriction

The original disallowed characters from LogEventEntity were correct, but not in AzureTableStorageEntityFactory, causing the errors in #10.

Author: ChrisSimmons

src/Serilog.Sinks.AzureTableStorage/ObjectNaming.cs

@@ -0,0 +1,28 @@
+using System.Text.RegularExpressions;
+
+namespace Serilog.Sinks.AzureTableStorage
+{
+    /// <summary>
+    /// Defines naming restrictions for Azure Table Storage objects
+    /// </summary>
+    public static class ObjectNaming
+    {
+        /// <summary>
+        /// The regex defining characters which are disallowed for key field values.
+        /// </summary>
+        /// <see href="https://msdn.microsoft.com/en-us/library/azure/dd179338.aspx"/>
+        public static readonly Regex KeyFieldValueCharactersNotAllowedMatch =
+            new Regex(@"(\\|/|#|\?|[\x00-\x1f]|[\x7f-\x9f])");
+
+        /// <summary>
+        /// Given a <param name="keyValue">key value</param>, returns a value
+        /// which has been 'cleaned' of any disallowed characters and trimmed
+        /// to the allowed length.
+        /// </summary>
+        public static string GetValidKeyValue(string keyValue)
+        {
+            keyValue = KeyFieldValueCharactersNotAllowedMatch.Replace(keyValue, "");
+            return keyValue.Length > 1024 ? keyValue.Substring(0, 1024) : keyValue;
+        }
+    }
+}

src/Serilog.Sinks.AzureTableStorage/Sinks/AzureTableStorage/LogEventEntity.cs

@@ -32,8 +32,6 @@ namespace Serilog.Sinks.AzureTableStorage
     /// </remarks>
     public class LogEventEntity : TableEntity
     {
-        static readonly Regex RowKeyNotAllowedMatch = new Regex(@"(\\|/|#|\?|[\x00-\x1f]|[\x7f-\x9f])");
-
         /// <summary>
         /// Default constructor for the Storage Client library to re-hydrate entities when querying.
         /// </summary>
@@ -62,7 +60,7 @@ public LogEventEntity(LogEvent log, IFormatProvider formatProvider, long partiti
         // http://msdn.microsoft.com/en-us/library/windowsazure/dd179338.aspx
         static string GetValidRowKey(string rowKey)
         {
-            rowKey = RowKeyNotAllowedMatch.Replace(rowKey, "");
+            rowKey = ObjectNaming.KeyFieldValueCharactersNotAllowedMatch.Replace(rowKey, "");
             return rowKey.Length > 1024 ? rowKey.Substring(0, 1024) : rowKey;
         }
 

src/Serilog.Sinks.AzureTableStorage/Sinks/AzureTableStorageWithProperties/AzureTableStorageEntityFactory.cs

@@ -27,9 +27,6 @@ namespace Serilog.Sinks.AzureTableStorage
 	/// </summary>
 	public static class AzureTableStorageEntityFactory
 	{
-		// Valid RowKey name characters
-		static readonly Regex _rowKeyNotAllowedMatch = new Regex(@"(\\|/|#|\n|\r|\?)");
-
 		// Azure tables support a maximum of 255 properties. PartitionKey, RowKey and Timestamp
 		// bring the maximum to 252.
 		const int _maxNumberOfPropertiesPerRow = 252;
@@ -99,7 +96,7 @@ public static DynamicTableEntity CreateEntityWithProperties(LogEvent logEvent, I
 		/// </returns>
 		public static string GetValidStringForTableKey(string s)
 		{
-			return _rowKeyNotAllowedMatch.Replace(s, "");
+            return ObjectNaming.KeyFieldValueCharactersNotAllowedMatch.Replace(s, "");
 		}
 
 		// Generate a valid partition key from event timestamp.
@@ -133,7 +130,7 @@ private static string GenerateValidRowKey(LogEvent logEvent, string additionalRo
 				postfixBuilder.Append('|').Append(additionalRowKeyPostfix);
 			}
 
-			// Append GUID to postfix	
+			// Append GUID to postfix
 			postfixBuilder.Append('|').Append(Guid.NewGuid());
 
 			// Truncate prefix if too long