Add a little more safety to Skippers

SabreTools.DatFiles/Rebuilder.cs

@@ -60,9 +60,6 @@ namespace SabreTools.DatFiles
             if (outputFormat == OutputFormat.Folder && datFile.Header.ForcePacking != PackingFlag.None)
                 outputFormat = GetOutputFormat(datFile.Header.ForcePacking);
 
-            // Preload the Skipper list
-            SkipperMatch.Init();
-
             #endregion
 
             bool success = true;
@@ -202,8 +199,6 @@ namespace SabreTools.DatFiles
             if (outputFormat == OutputFormat.Folder && datFile.Header.ForcePacking != PackingFlag.None)
                 outputFormat = GetOutputFormat(datFile.Header.ForcePacking);
 
-            // Preload the Skipper list
-            SkipperMatch.Init();
 
             #endregion
 
@@ -419,6 +414,7 @@ namespace SabreTools.DatFiles
             if (datFile.Header.HeaderSkipper != null)
             {
                 // Check to see if we have a matching header first
+                SkipperMatch.Init();
                 SkipperRule rule = SkipperMatch.GetMatchingRule(fileStream, Path.GetFileNameWithoutExtension(datFile.Header.HeaderSkipper));
 
                 // If there's a match, create the new file to write

SabreTools.FileTypes/BaseFile.cs

@@ -295,6 +295,7 @@ namespace SabreTools.FileTypes
             // Try to match the supplied header skipper
             if (header != null)
             {
+                SkipperMatch.Init();
                 var rule = SkipperMatch.GetMatchingRule(input, Path.GetFileNameWithoutExtension(header));
 
                 // If there's a match, transform the stream before getting info

SabreTools.Skippers/SkipperMatch.cs

@@ -26,7 +26,7 @@ namespace SabreTools.Skippers
         /// <summary>
         /// Header skippers represented by a list of skipper objects
         /// </summary>
-        private static List<SkipperFile> List;
+        private static List<SkipperFile> Skippers = null;
 
         /// <summary>
         /// Local paths
@@ -45,13 +45,24 @@ namespace SabreTools.Skippers
         /// <summary>
         /// Initialize static fields
         /// </summary>
-        public static void Init()
+        /// <param name="experimental">True to enable internal header skipper generation, false to use file-based generation (default)</param>
+        public static void Init(bool experimental = false)
         {
+            // If the list is populated, don't add to it
+            if (Skippers != null)
+                return;
+
+            // If we're using internal skipper generation
+            if (experimental)
+                PopulateSkippersInternal();
+
+            // If we're using file-based skipper generation
+            else
                 PopulateSkippers();
         }
 
         /// <summary>
-        /// Populate the entire list of header Skippers
+        /// Populate the entire list of header skippers from physical files
         /// </summary>
         /// <remarks>
         /// http://mamedev.emulab.it/clrmamepro/docs/xmlheaders.txt
@@ -60,18 +71,18 @@ namespace SabreTools.Skippers
         private static void PopulateSkippers()
         {
             // Ensure the list exists
-            if (List == null)
+            if (Skippers == null)
-                List = new List<SkipperFile>();
+                Skippers = new List<SkipperFile>();
 
             // Get skippers for each known header type
             foreach (string skipperFile in Directory.EnumerateFiles(LocalPath, "*", SearchOption.AllDirectories))
             {
-                List.Add(new SkipperFile(Path.GetFullPath(skipperFile)));
+                Skippers.Add(new SkipperFile(Path.GetFullPath(skipperFile)));
             }
         }
 
         /// <summary>
-        /// Populate the entire list of header skippers
+        /// Populate the entire list of header skippers from generated objects
         /// </summary>
         /// <remarks>
         /// http://mamedev.emulab.it/clrmamepro/docs/xmlheaders.txt
@@ -80,19 +91,19 @@ namespace SabreTools.Skippers
         private static void PopulateSkippersInternal()
         {
             // Ensure the list exists
-            if (List == null)
+            if (Skippers == null)
-                List = new List<SkipperFile>();
+                Skippers = new List<SkipperFile>();
 
             // Get skippers for each known header type
-            List.Add(GetAtari7800());
+            Skippers.Add(GetAtari7800());
-            List.Add(GetAtariLynx());
+            Skippers.Add(GetAtariLynx());
-            List.Add(GetCommodorePSID());
+            Skippers.Add(GetCommodorePSID());
-            List.Add(GetNECPCEngine());
+            Skippers.Add(GetNECPCEngine());
-            List.Add(GetNintendo64());
+            Skippers.Add(GetNintendo64());
-            List.Add(GetNintendoEntertainmentSystem());
+            Skippers.Add(GetNintendoEntertainmentSystem());
-            List.Add(GetNintendoFamicomDiskSystem());
+            Skippers.Add(GetNintendoFamicomDiskSystem());
-            List.Add(GetSuperNintendoEntertainmentSystem());
+            Skippers.Add(GetSuperNintendoEntertainmentSystem());
-            List.Add(GetSuperFamicomSPC());
+            Skippers.Add(GetSuperFamicomSPC());
         }
 
         /// <summary>
@@ -132,7 +143,7 @@ namespace SabreTools.Skippers
             // Loop through and find a Skipper that has the right name
             logger.Verbose("Beginning search for matching header skip rules");
             List<SkipperFile> tempList = new List<SkipperFile>();
-            tempList.AddRange(List);
+            tempList.AddRange(Skippers);
 
             // Loop through all known SkipperFiles
             foreach (SkipperFile skipper in tempList)

SabreTools/Features/Extract.cs

@@ -69,6 +69,7 @@ The following systems have headers that this program can work with:
             logger.User($"\nGetting skipper information for '{file}'");
 
             // Get the skipper rule that matches the file, if any
+            SkipperMatch.Init();
             SkipperRule rule = SkipperMatch.GetMatchingRule(file, string.Empty);
 
             // If we have an empty rule, return false