/// <summary>
/// Writes a message file.
/// </summary>
/// <param name="path">The file path.</param>
/// <param name="msg">The message.</param>
/// <param name="msgInfo">The message metadata.</param>
internal void WriteMessage(string path, QueuedMsg msg, QueuedMsgInfo msgInfo)
{
byte[] md5Hash;
using (var fsMsg = new EnhancedFileStream(path, FileMode.Create, FileAccess.ReadWrite))
{
// Write the file header
fsMsg.WriteInt32(MsgMagic); // Magic Number
fsMsg.WriteInt32(0); // Format Version
fsMsg.WriteInt32(0); // Reserved
fsMsg.WriteBytesNoLen(md5Zeros); // MD5 hash placeholder
// Write the message body.
fsMsg.WriteBytes32(msg.BodyRaw);
// Write the metadata.
fsMsg.WriteString16(msgInfo.ToString());
// Compute and save the MD5 hash
fsMsg.Position = MsgHeaderSize;
md5Hash = MD5Hasher.Compute(fsMsg, fsMsg.Length - fsMsg.Position);
fsMsg.Position = MsgMD5Offset;
fsMsg.WriteBytesNoLen(md5Hash);
}
}
/// <summary>
/// Writes an <see cref="IOperation" /> to the log.
/// </summary>
/// <param name="resource">The parent <see cref="ITransactedResource" /> responsible for serializing the operation.</param>
/// <param name="operation">The operation to be written.</param>
/// <remarks>
/// <note>
/// This property can only be called if the operation log is in <see cref="OperationLogMode.Undo" />
/// mode.
/// </note>
/// </remarks>
/// <exception cref="TransactionException">Thrown if the log isn't open or if the mode isn't <see cref="OperationLogMode.Undo" />.</exception>
public void Write(ITransactedResource resource, IOperation operation)
{
long cbPos;
long cb;
using (TimedLock.Lock(this))
{
if (file == null)
{
throw new TransactionException(ClosedMsg);
}
if (mode != OperationLogMode.Undo)
{
throw new TransactionException("Write is available only when the log is in UNDO mode.");
}
file.WriteInt32(Magic); // Magic number
cbPos = file.Position; // Length place holder
file.WriteInt32(0);
file.WriteString32(operation.Description); // Description
resource.WriteOperation(file, operation); // Serialized operation
cb = file.Position - cbPos - 4;
if (cb < 0 || cb > int.MaxValue)
{
throw new TransactionException("ITransactedResource.WriteOperation() returned with an unexpected stream position.");
}
file.Position = cbPos;
file.WriteInt32((int)cb);
file.Position = file.Length;
file.Flush();
}
}
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);
}
}
}
/// <summary>
/// Writes the index file.
/// </summary>
/// <param name="path">The target file path.</param>
/// <param name="phrases">The phrases to be written.</param>
private void SaveIndexTo(string path, Phrase[] phrases)
{
using (var fs = new EnhancedFileStream(path, FileMode.Create))
{
fs.WriteInt32(Magic);
fs.WriteInt32(phrases.Length);
foreach (var phrase in phrases)
{
fs.WriteString16(phrase.PhraseType.ToString());
fs.WriteString32(phrase.Text);
fs.WriteString16(phrase.Voice);
fs.WriteString16(phrase.ActualVoice);
fs.WriteString16(phrase.Encoding.ToString());
fs.WriteString16(phrase.SampleRate.ToString());
fs.WriteInt64(phrase.LastAccessUtc.Ticks);
fs.WriteString16(phrase.Path);
}
}
}
/// <summary>
/// Loads the message index file. If the index does not exist or is corrupt then
/// the index will be rebuilt by performing a full scan of message files under
/// the root folder.
/// </summary>
/// <param name="newIndexFile">Pass as <c>true</c> if a new index file is being created.</param>
private void LoadIndex(bool newIndexFile)
{
string formatErr = string.Format("Invalid or missing index file [{0}].", indexPath);
int cMessages;
string[] files;
Dictionary <Guid, string> msgFiles;
TimedLock.AssertLocked(this);
messages = new Dictionary <Guid, QueuedMsgInfo>();
// List the message files and build a hash table mapping each message GUID
// the fully qualified path to the file.
files = Helper.GetFilesByPattern(root + "*.msg", SearchOption.AllDirectories);
msgFiles = new Dictionary <Guid, string>(files.Length);
foreach (string path in files)
{
string file = Path.GetFileName(path).ToLowerInvariant();
Guid msgID;
if (!file.EndsWith(".msg"))
{
continue;
}
try
{
msgID = new Guid(file.Substring(0, file.Length - 4));
}
catch
{
continue;
}
msgFiles[msgID] = path;
}
// Load the index file.
try
{
// Parse the index file header
fsIndex.Position = 0;
if (fsIndex.ReadInt32() != IndexMagic) // Magic Number
{
throw new FormatException(formatErr);
}
if (fsIndex.ReadInt32() != 0) // Format Version
{
throw new FormatException(formatErr);
}
fsIndex.ReadInt32(); // Reserved
if (fsIndex.ReadInt32() != 0)
{
throw new FormatException(string.Format("Index file [{0}] was not closed properly. Full message folder scan will be performed.", indexPath));
}
cMessages = fsIndex.ReadInt32(); // Message Count
// Parse the message metadata
for (int i = 0; i < cMessages; i++)
{
QueuedMsgInfo msgInfo;
msgInfo = new QueuedMsgInfo(fsIndex.ReadString16());
msgInfo.PersistID = msgInfo.ID;
msgInfo.ProviderData = root + fsIndex.ReadString16(); // Make the paths absolute
messages[msgInfo.ID] = msgInfo;
}
// Perform an extra consistency check by listing all of the message files
// under the root folder and comparing the message GUIDs encoded into the
// file names with the GUIDs loaded from the index file and then bringing
// the index into sync with the actual message files.
bool updated = false;
int cLoaded = 0;
// Delete any metadata for messages that exist in the index
// but don't exist on the file system.
var delList = new List <Guid>();
foreach (Guid msgID in messages.Keys)
{
if (!msgFiles.ContainsKey(msgID))
{
delList.Add(msgID);
}
}
foreach (Guid msgID in delList)
{
messages.Remove(msgID);
}
if (delList.Count > 0)
{
updated = true;
SysLog.LogWarning(string.Format("Message index [{0}] has message metadata for messages that do not exist. [{1}] messages will be removed from the index.", indexPath, delList.Count));
}
// Load metadata for messages that exist in the file system
// but were not in the index.
foreach (Guid msgID in msgFiles.Keys)
{
if (!messages.ContainsKey(msgID))
{
string path = msgFiles[msgID];
try
{
messages[msgID] = ReadMessageMetadata(msgID, path);
cLoaded++;
}
catch (Exception e)
{
SysLog.LogException(e);
}
}
}
if (cLoaded > 0)
{
updated = true;
SysLog.LogWarning(string.Format("Message index [{0}] is missing metadata for [{1}] messages. Missing entries will be added.", indexPath, cLoaded));
}
if (updated)
{
SaveIndex(true);
}
// Mark the index as "open" for crash detection.
fsIndex.Position = OpenFlagOffset;
fsIndex.WriteInt32(1);
fsIndex.Flush();
}
catch
{
if (newIndexFile)
{
SysLog.LogWarning("Rebuilding missing message index file [{0}].", indexPath);
}
else
{
SysLog.LogWarning("Rebuilding corrupt message index file [{0}].", indexPath);
}
// Clear the index file if there was a serious error and then
// rebuild it from scratch by scanning the message metadata.
fsIndex.SetLength(0);
fsIndex.Flush();
messages.Clear();
foreach (Guid msgID in msgFiles.Keys)
{
try
{
messages.Add(msgID, ReadMessageMetadata(msgID, msgFiles[msgID]));
}
catch (Exception e2)
{
SysLog.LogException(e2);
}
}
// Save the index, marking the file as "open" for crash detection
SaveIndex(true);
}
}