[CHDFile, Utilities] The great CHD cleanup

SabreTools.Library/FileTypes/CHDFile.cs

@@ -1,7 +1,4 @@
-using System;
+using SabreTools.Library.Data;
-using System.Linq;
-
-using SabreTools.Library.Data;
 using SabreTools.Library.Tools;
 
 #if MONO
@@ -88,7 +85,7 @@ namespace SabreTools.Library.FileTypes
 	/// 0x68-0x7b - Parent SHA-1
 	/// ----------------------------------------------
 	/// </remarks>
-	public class CHDFile : BaseFile, IDisposable
+	public class CHDFile : BaseFile
 	{
 		#region Private instance variables
 
@@ -110,12 +107,61 @@ namespace SabreTools.Library.FileTypes
 		private uint m_mapentrybytes;    // length of each entry in a map
 
 		// additional required vars
+		private uint? _headerVersion;
 		private BinaryReader m_br;       // Binary reader representing the CHD stream
 
 		#endregion
 
+		#region Pubically facing variables
+
+		public uint? Version
+		{
+			get
+			{
+				if (_headerVersion == null)
+				{
+					_headerVersion = ValidateHeaderVersion();
+				}
+
+				return _headerVersion;
+			}
+		}
+
+		#endregion
+
 		#region Constructors
 
+		/// <summary>
+		/// Create a new, blank CHDFile
+		/// </summary>
+		public CHDFile()
+		{
+			this._fileType = FileType.CHD;
+		}
+
+		/// <summary>
+		/// Create a new CHDFile from an input file
+		/// </summary>
+		/// <param name="filename"></param>
+		public CHDFile(string filename)
+			: base(filename)
+		{
+			_fileType = FileType.CHD;
+			m_br = new BinaryReader(Utilities.TryOpenRead(filename));
+
+			_headerVersion = ValidateHeaderVersion();
+
+			byte[] hash = GetHashFromHeader();
+			if (hash.Length == Constants.MD5Length)
+			{
+				_md5 = hash;
+			}
+			else if (hash.Length == Constants.SHA1Length)
+			{
+				_sha1 = hash;
+			}
+		}
+
 		/// <summary>
 		/// Create a new CHDFile from an input stream
 		/// </summary>
@@ -124,14 +170,18 @@ namespace SabreTools.Library.FileTypes
 		{
 			_fileType = FileType.CHD;
 			m_br = new BinaryReader(chdstream);
-		}
 
-		/// <summary>
+			_headerVersion = ValidateHeaderVersion();
-		/// Dispose of the CHDFile
+
-		/// </summary>
+			byte[] hash = GetHashFromHeader();
-		public void Dispose()
+			if (hash.Length == Constants.MD5Length)
 			{
-			m_br.Dispose();
+				_md5 = hash;
+			}
+			else if (hash.Length == Constants.SHA1Length)
+			{
+				_sha1 = hash;
+			}
 		}
 
 		#endregion
@@ -142,7 +192,9 @@ namespace SabreTools.Library.FileTypes
 		/// Validate the initial signature, version, and header size
 		/// </summary>
 		/// <returns>Unsigned int containing the version number, null if invalid</returns>
-		public uint? ValidateHeaderVersion()
+		private uint? ValidateHeaderVersion()
+		{
+			try
 			{
 				// Seek to the beginning to make sure we're reading the correct bytes
 				m_br.BaseStream.Seek(0, SeekOrigin.Begin);
@@ -180,12 +232,17 @@ namespace SabreTools.Library.FileTypes
 
 				return m_version;
 			}
+			catch
+			{
+				return null;
+			}
+		}
 
 		/// <summary>
 		/// Get the internal MD5 (v1, v2) or SHA-1 (v3, v4, v5) from the CHD
 		/// </summary>
 		/// <returns>MD5 as a byte array, null on error</returns>
-		public byte[] GetHashFromHeader()
+		private byte[] GetHashFromHeader()
 		{
 			// Validate the header by default just in case
 			uint? version = ValidateHeaderVersion();
@@ -194,6 +251,8 @@ namespace SabreTools.Library.FileTypes
 			byte[] hash;
 
 			// Now parse the rest of the header according to the version
+			try
+			{
 				switch (version)
 				{
 					case 1:
@@ -216,6 +275,12 @@ namespace SabreTools.Library.FileTypes
 						// throw CHDERR_INVALID_FILE;
 						return null;
 				}
+			}
+			catch
+			{
+				// throw CHDERR_INVALID_FILE;
+				return null;
+			}
 
 			return hash;
 		}

SabreTools.Library/Tools/Utilities.cs

@@ -1040,9 +1040,9 @@ namespace SabreTools.Library.Tools
 		public static BaseFile GetCHDInfo(string input)
 		{
 			FileStream fs = TryOpenRead(input);
-			BaseFile datItem = GetCHDInfo(fs);
+			BaseFile chd = GetCHDInfo(fs);
 			fs.Dispose();
-			return datItem;
+			return chd;
 		}
 
 		/// <summary>
@@ -1371,32 +1371,6 @@ namespace SabreTools.Library.Tools
 			}
 		}
 
-		/// <summary>
-		/// Get if file has a known CHD header
-		/// </summary>
-		/// <param name="input">Filename of possible CHD</param>
-		/// <returns>True if the file has a valid CHD header, false otherwise</returns>
-		public static bool HasCHDHeader(string input)
-		{
-			FileStream fs = TryOpenRead(input);
-			bool output = HasCHDHeader(fs);
-			fs.Dispose();
-			return output;
-		}
-
-		/// <summary>
-		/// Get if file is a valid CHD
-		/// </summary>
-		/// <param name="input">Filename of possible CHD</param>
-		/// <returns>True if the file is a valid CHD, false otherwise</returns>
-		public static bool IsValidCHD(string input)
-		{
-			BaseFile baseFile = GetCHDInfo(input);
-			return baseFile != null
-				&& (((CHDFile)baseFile).MD5 != null
-					|| ((CHDFile)baseFile).SHA1 != null);
-		}
-
 		/// <summary>
 		/// Retrieve a list of files from a directory recursively in proper order
 		/// </summary>
@@ -1925,7 +1899,7 @@ namespace SabreTools.Library.Tools
 			long offset = 0, bool keepReadOpen = false, bool chdsAsFiles = true)
 		{
 			// We first check to see if it's a CHD
-			if (chdsAsFiles == false && HasCHDHeader(input))
+			if (chdsAsFiles == false && GetCHDInfo(input) != null)
 			{
 				// Seek to the starting position, if one is set
 				try
@@ -1952,8 +1926,8 @@ namespace SabreTools.Library.Tools
 					Globals.Logger.Warning("Stream does not support seeking. Stream position not changed");
 				}
 
-				// Get the Disk from the information
+				// Get the BaseFile from the information
-				BaseFile disk = GetCHDInfo(input);
+				BaseFile chd = GetCHDInfo(input);
 
 				// Seek to the beginning of the stream if possible
 				try
@@ -1974,7 +1948,7 @@ namespace SabreTools.Library.Tools
 					input.Dispose();
 				}
 
-				return disk;
+				return chd;
 			}
 
 			BaseFile rom = new BaseFile() 
@@ -2130,54 +2104,8 @@ namespace SabreTools.Library.Tools
 		/// </remarks>
 		public static BaseFile GetCHDInfo(Stream input)
 		{
-			// Get a CHD object to store the data
 			CHDFile chd = new CHDFile(input);
-
+			return (chd.Version != null && (chd.MD5 != null || chd.SHA1 != null) ? chd : null);
-			// Ensure that the header is valid
-			byte[] hash = chd.GetHashFromHeader();
-
-			// Set the proper hash of the Disk to return
-			if (hash.Length == Constants.MD5Length)
-			{
-				chd.MD5 = hash;
-				return chd;
-			}
-			else if (hash.Length == Constants.SHA1Length)
-			{
-				chd.SHA1 = hash;
-				return chd;
-			}
-
-			return null;
-		}
-
-		/// <summary>
-		/// Get if stream has a known CHD header
-		/// </summary>
-		/// <param name="input">Stream of possible CHD</param>
-		/// <returns>True if the stream has a valid CHD header, false otherwise</returns>
-		public static bool HasCHDHeader(Stream input)
-		{
-			// Get a CHD object to store the data
-			CHDFile chd = new CHDFile(input);
-
-			// Now try to get the header version
-			uint? version = chd.ValidateHeaderVersion();
-
-			return version != null;
-		}
-
-		/// <summary>
-		/// Get if stream is a valid CHD
-		/// </summary>
-		/// <param name="input">Stream of possible CHD</param>
-		/// <returns>True if the stream is a valid CHD, false otherwise</returns>
-		public static bool IsValidCHD(Stream input)
-		{
-			BaseFile baseFile = GetCHDInfo(input);
-			return baseFile != null
-				&& (((CHDFile)baseFile).MD5 != null
-					|| ((CHDFile)baseFile).SHA1 != null);
 		}
 
 		#endregion