/// <summary> /// Reads the metadata from a message file. /// </summary> /// <param name="msgID">The message ID.</param> /// <param name="path">Fully qualified path to the message file.</param> /// <returns>The <see cref="QueuedMsgInfo" />.</returns> internal QueuedMsgInfo ReadMessageMetadata(Guid msgID, string path) { QueuedMsgInfo msgInfo; int cbBody; byte[] md5Hash; long savePos; using (var fsMsg = new EnhancedFileStream(path, FileMode.Open, FileAccess.ReadWrite)) { try { // Read the message file header if (fsMsg.ReadInt32() != MsgMagic) // Magic Number { throw new Exception(); } if (fsMsg.ReadInt32() != 0) // Format Version { throw new Exception(); } fsMsg.ReadInt32(); // Reserved // Verify that the MD5 hash saved in then file matches the // hash computed for the remainder of the file as it exists // right now. md5Hash = fsMsg.ReadBytes(MD5Hasher.DigestSize); savePos = fsMsg.Position; if (!Helper.ArrayEquals(md5Hash, MD5Hasher.Compute(fsMsg, fsMsg.Length - fsMsg.Position))) { throw new FormatException(string.Format("Message file [{0}] is corrupt. MD5 digests do not match.", path)); } fsMsg.Position = savePos; // Skip over the message body data cbBody = fsMsg.ReadInt32(); fsMsg.Position = fsMsg.Position + cbBody; // Read the metadata and add the provider specific information msgInfo = new QueuedMsgInfo(fsMsg.ReadString16()); msgInfo.PersistID = msgInfo.ID; msgInfo.ProviderData = path; return(msgInfo); } catch { throw new FormatException(string.Format("Bad message file [{0}].", path)); } } }
private OperationLogMode mode; // The current mode /// <summary> /// Opens or creates a file operation log file. /// </summary> /// <param name="path">The path to the log file.</param> /// <param name="transactionID">The log's transaction <see cref="Guid" />.</param> /// <remarks> /// New logs will be created in <see cref="OperationLogMode.Undo" /> mode. /// </remarks> public FileOperationLog(string path, Guid transactionID) { this.path = Path.GetFullPath(path); this.file = new EnhancedFileStream(path, FileMode.OpenOrCreate, FileAccess.ReadWrite); if (file.Length == 0) { // Initialize a new file file.WriteInt32(Magic); file.WriteInt32(0); file.WriteInt32(0); file.WriteInt32((int)OperationLogMode.Undo); file.WriteBytesNoLen(transactionID.ToByteArray()); file.Flush(); } else { // Open an existing file. try { if (file.ReadInt32() != Magic || // Magic number file.ReadInt32() != 0) { // Format Versopn throw new Exception(); } file.ReadInt32(); // Reserved switch (file.ReadInt32()) // Mode { case (int)OperationLogMode.Undo: mode = OperationLogMode.Undo; break; case (int)OperationLogMode.Redo: mode = OperationLogMode.Redo; break; default: throw new Exception(); } this.transactionID = new Guid(file.ReadBytes(16)); if (transactionID != this.transactionID) { throw new Exception(); } } catch { throw new TransactionException(CorruptMsg); } } }
//--------------------------------------------------------------------- // Static members /// <summary> /// Verifies that a log file is not corrupt. /// </summary> /// <param name="path">The path to the log file.</param> /// <param name="transactionID">Returns as the file's transaction <see cref="Guid" />.</param> /// <returns><c>true</c> if the log file is valid, <c>false</c> if it is corrupt.</returns> public static bool Validate(string path, out Guid transactionID) { int cb; try { using (var file = new EnhancedFileStream(path, FileMode.Open, FileAccess.ReadWrite)) { if (file.ReadInt32() != Magic || // Magic number file.ReadInt32() != 0) { // Format Versopn throw new Exception(); } switch (file.ReadInt32()) // Mode { case (int)OperationLogMode.Undo: case (int)OperationLogMode.Redo: break; default: throw new Exception(); } file.ReadInt32(); // Reserved transactionID = new Guid(file.ReadBytes(16)); while (!file.Eof) { if (file.ReadInt32() != Magic) { throw new Exception(); } cb = file.ReadInt32(); if (cb < 0 || cb + file.Position > file.Length) { throw new Exception(); } file.Position += cb; } return(true); } } catch { transactionID = Guid.Empty; return(false); } }