Clearing suffixes dictionary when a threshold is hit to avoid memory starvation. Adding further method header comments.

--HG--
branch : 1.x

src/Orchard/Logging/OrchardFileAppender.cs

@@ -9,8 +9,16 @@ namespace Orchard.Logging {
         /// </summary>
         private static readonly Dictionary<string, int> _suffixes = new Dictionary<string, int>();
 
+        /// <summary>
+        /// The number of suffix attempts that will be made on each OpenFile method call.
+        /// </summary>
         private const int Retries = 50;
 
+        /// <summary>
+        /// Maximum number of suffixes recorded before a cleanup happens to recycle memory.
+        /// </summary>
+        private const int MaxSuffixes = 100;
+
         /// <summary>
         /// Opens the log file adding an incremental suffix to the filename if required due to an openning failure (usually, locking).
         /// </summary>
@@ -22,6 +30,10 @@ namespace Orchard.Logging {
                 string completeFilename = GetNextOutputFileName(fileName);
                 string currentFilename = fileName;
 
+                if (_suffixes.Count > MaxSuffixes) {
+                    _suffixes.Clear();
+                }
+
                 if (!_suffixes.ContainsKey(completeFilename)) {
                     _suffixes[completeFilename] = 0;
                 }
@@ -48,6 +60,11 @@ namespace Orchard.Logging {
             }
         }
 
+        /// <summary>
+        /// Calls the base class OpenFile method. Allows this method to be mocked.
+        /// </summary>
+        /// <param name="fileName">The filename as specified in the configuration file.</param>
+        /// <param name="append">Boolean flag indicating weather the log file should be appended if it already exists.</param>
         protected virtual void BaseOpenFile(string fileName, bool append) {
             base.OpenFile(fileName, append);
         }