/// <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>
/// Updates a message file's metadata.
/// </summary>
/// <param name="path">The file path.</param>
/// <param name="msgInfo">The message metadata.</param>
internal void WriteMessageMetadata(string path, QueuedMsgInfo msgInfo)
{
using (var fsMsg = new EnhancedFileStream(path, FileMode.Open, FileAccess.ReadWrite))
{
// Seek past the message's header and body.
int cbBody;
byte[] md5Hash;
fsMsg.Position = MsgHeaderSize;
cbBody = fsMsg.ReadInt32();
fsMsg.Position = fsMsg.Position + cbBody;
// Write the metadata and truncate the file.
fsMsg.WriteString16(msgInfo.ToString());
fsMsg.SetLength(fsMsg.Position);
// Regenerate the MD5 Hash
fsMsg.Position = MsgMD5Offset + MD5Hasher.DigestSize;
md5Hash = MD5Hasher.Compute(fsMsg, fsMsg.Length - fsMsg.Position);
fsMsg.Position = MsgMD5Offset;
fsMsg.WriteBytesNoLen(md5Hash);
}
}
/// <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));
}
}
}
/// <summary>
/// Adds the message information to the end other queued messages with the same priority.
/// </summary>
/// <param name="transaction">The current <see cref="BaseTransaction" /> (or <c>null</c>).</param>
/// <param name="msgInfo">The message information.</param>
public void Enqueue(BaseTransaction transaction, QueuedMsgInfo msgInfo)
{
var queue = queuesByPriority[(int)msgInfo.Priority];
var lockID = transaction != null ? transaction.ID : Guid.Empty;
msgInfo.LockID = lockID;
queue.Enqueue(msgInfo);
messages.Add(msgInfo.ID, msgInfo);
count++;
}
/// <summary>
/// Adds a message to the backing store and updates the <see cref="QueuedMsgInfo.PersistID" />
/// and <see cref="QueuedMsgInfo.ProviderData" /> fields in the <see cref="QueuedMsgInfo" />
/// instance passed.
/// </summary>
/// <param name="msgInfo">The message metadata.</param>
/// <param name="msg">The message.</param>
public void Add(QueuedMsgInfo msgInfo, QueuedMsg msg)
{
using (TimedLock.Lock(this))
{
if (messages == null)
{
throw new ObjectDisposedException(this.GetType().Name);
}
msgInfo.PersistID = msg.ID;
msgInfo.ProviderData = msg;
messages[msg.ID] = msgInfo;
}
}
/// <summary>
/// Adds a message to the backing store and updates the <see cref="QueuedMsgInfo.PersistID" />
/// and <see cref="QueuedMsgInfo.ProviderData" /> fields in the <see cref="QueuedMsgInfo" />
/// instance passed.
/// </summary>
/// <param name="msgInfo">The message metadata.</param>
/// <param name="msg">The message.</param>
public void Add(QueuedMsgInfo msgInfo, QueuedMsg msg)
{
using (TimedLock.Lock(this))
{
if (messages == null)
{
throw new ObjectDisposedException(this.GetType().Name);
}
string msgPath;
msgPath = GetMessagePath(msgInfo.ID, true);
WriteMessage(msgPath, msg, msgInfo);
msgInfo.PersistID = msg.ID;
msgInfo.ProviderData = msgPath;
messages[msg.ID] = msgInfo;
}
}
/// <summary>
/// Removes a specific message from the queue.
/// </summary>
/// <param name="msgInfo">Information about the message being removed.</param>
/// <returns><c>true</c> if the message was found and returned.</returns>
/// <remarks>
/// This method is used during transactional processing when undoing or redoing
/// transactions.
/// </remarks>
public bool Remove(QueuedMsgInfo msgInfo)
{
// This method will probably be called most often to removed a message
// enqueued during a transaction that is being rolled back. In this
// case, the transaction will be at the end of the queue so to optimize
// performance I'm going to search from the end of the queues to the
// beginning.
var queue = queuesByPriority[(int)msgInfo.Priority];
for (int i = queue.Count - 1; i >= 0; i--)
{
if (queue[i].ID == msgInfo.ID)
{
queue.RemoveAt(i);
return(true);
}
}
return(false);
}
/// <summary>
/// Constructor.
/// </summary>
/// <param name="msgInfo">A <see cref="QueuedMsgInfo" /> instance with the header information.</param>
/// <param name="bodyRaw">The raw message body.</param>
/// <param name="deserialize">
/// Pass <c>true</c> to deserialize the message body, <c>false</c> to limit
/// deserialization to the message headers.
/// </param>
/// <remarks>
/// <note>
/// This constructor is provided for applications that need to implement
/// a custom <see cref="IMsgQueueStore" />.
/// </note>
/// </remarks>
public QueuedMsg(QueuedMsgInfo msgInfo, byte[] bodyRaw, bool deserialize)
{
this.id = msgInfo.ID;
this.targetEP = msgInfo.TargetEP;
this.responseEP = msgInfo.ResponseEP;
this.sessionID = msgInfo.SessionID;
this.sendTime = msgInfo.SendTime;
this.expireTime = msgInfo.ExpireTime;
this.flags = msgInfo.Flags;
this.priority = msgInfo.Priority;
this.bodyRaw = bodyRaw;
if (deserialize)
{
body = Serialize.FromBinary(bodyRaw);
}
else
{
body = null;
}
}
/// <summary>
/// Returns a shallowm clone of this instance.
/// </summary>
/// <returns>The cloned <see cref="QueuedMsgInfo" />.</returns>
public QueuedMsgInfo Clone()
{
var clone = new QueuedMsgInfo();
clone.PersistID = this.PersistID;
clone.ID = this.ID;
clone.SessionID = this.SessionID;
clone.TargetEP = this.TargetEP;
clone.ResponseEP = this.ResponseEP;
clone.Priority = this.Priority;
clone.Flags = this.Flags;
clone.SendTime = this.SendTime;
clone.ExpireTime = this.ExpireTime;
clone.DeliveryTime = this.DeliveryTime;
clone.BodySize = this.BodySize;
clone.DeliveryAttempts = this.DeliveryAttempts;
clone.LockID = this.LockID;
clone.ProviderData = this.ProviderData;
return(clone);
}
public FlushInfo(string queuedEP, QueuedMsgInfo msgInfo)
{
this.QueueEP = queuedEP;
this.MsgInfo = msgInfo;
}
/// <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);
}
}
