Add Opera FileSystem support (#90)

* Add Opera FileSystem support

* Fix tests

SabreTools.Data.Extensions/CDROMExtensions.cs

@@ -107,7 +107,7 @@ namespace SabreTools.Data.Extensions
         /// <summary>
         /// Creates a stream that provides only the user data of a CDROM stream
         /// </summary>
-        public class ISO9660Stream : Stream
+        public class UserDataStream : Stream
         {
             // Base CDROM stream (2352-byte sector)
             private readonly Stream _baseStream;
@@ -121,7 +121,7 @@ namespace SabreTools.Data.Extensions
             private long _isoSectorSize = Constants.Mode1DataSize;
 #pragma warning restore IDE0044
 
-            public ISO9660Stream(Stream inputStream)
+            public UserDataStream(Stream inputStream)
             {
                 if (!inputStream.CanSeek || !inputStream.CanRead)
                     throw new ArgumentException("Stream must be readable and seekable.", nameof(inputStream));

SabreTools.Data.Extensions/OperaFSExtensions.cs

@@ -0,0 +1,79 @@
+using SabreTools.Data.Models.OperaFS;
+using SabreTools.Matching;
+using SabreTools.Numerics;
+
+namespace SabreTools.Data.Extensions
+{
+    public static class OperaFSExtensions
+    {
+        /// <summary>
+        /// Compare two DirectoryDescriptor objects
+        /// </summary>
+        /// <param name="dir1">The provided DirectoryDescriptor</param>
+        /// <param name="dir2">The DirectoryDescriptor to compare against</param>
+        /// <returns>True if all fields are equal, otherwise false</returns>
+        public static bool EqualsExactly(this DirectoryDescriptor dir1, DirectoryDescriptor dir2)
+        {
+            if (dir1.NextBlock != dir2.NextBlock)
+                return false;
+            if (dir1.PreviousBlock != dir2.PreviousBlock)
+                return false;
+            if (dir1.Flags != dir2.Flags)
+                return false;
+            if (dir1.FirstFreeByte != dir2.FirstFreeByte)
+                return false;
+            if (dir1.FirstEntryOffset != dir2.FirstEntryOffset)
+                return false;
+            if (dir1.DirectoryRecords.Length != dir2.DirectoryRecords.Length)
+                return false;
+            
+            for (int i = 0; i < dir1.DirectoryRecords.Length; i++)
+            {
+                if (!dir1.DirectoryRecords[i].EqualsExactly(dir2.DirectoryRecords[i]))
+                    return false;
+            }
+
+            return true;
+        }
+
+        /// <summary>
+        /// Compare two DirectoryRecord objects
+        /// </summary>
+        /// <param name="dir1">The provided DirectoryRecord</param>
+        /// <param name="dir2">The DirectoryRecord to compare against</param>
+        /// <returns>True if all fields are equal, otherwise false</returns>
+        public static bool EqualsExactly(this DirectoryRecord dr1, DirectoryRecord dr2)
+        {
+            if ((byte)dr1.DirectoryRecordFlags != (byte)dr2.DirectoryRecordFlags)
+                return false;
+            if (!dr1.UniqueIdentifier.EqualsExactly(dr2.UniqueIdentifier))
+                return false;
+            if (!dr1.Type.EqualsExactly(dr2.Type))
+                return false;
+            if (dr1.BlockSize != dr2.BlockSize)
+                return false;
+            if (dr1.ByteCount != dr2.ByteCount)
+                return false;
+            if (dr1.BlockCount != dr2.BlockCount)
+                return false;
+            if (dr1.Burst != dr2.Burst)
+                return false;
+            if (dr1.Gap != dr2.Gap)
+                return false;
+            if (!dr1.Filename.EqualsExactly(dr2.Filename))
+                return false;
+            if (dr1.LastAvatarIndex != dr2.LastAvatarIndex)
+                return false;
+            if (dr1.AvatarList.Length != dr2.AvatarList.Length)
+                return false;
+            
+            for (int i = 0; i < dr1.AvatarList.Length; i++)
+            {
+                if (dr1.AvatarList[i] != dr2.AvatarList[i])
+                    return false;
+            }
+
+            return true;
+        }
+    }
+}