/// <summary>
/// Creates a new <see cref="DataPointScanner"/> instance.
/// </summary>
/// <param name="dataBlockAllocationTable"><see cref="ArchiveFileAllocationTable"/> for the file to be scanned.</param>
/// <param name="historianID">Historian ID to scan for.</param>
/// <param name="startTime">Desired start time.</param>
/// <param name="endTime">Desired end time.</param>
/// <param name="dataReadExceptionHandler">Read exception handler.</param>
public DataPointScanner(ArchiveFileAllocationTable dataBlockAllocationTable, int historianID, TimeTag startTime, TimeTag endTime, EventHandler<EventArgs<Exception>> dataReadExceptionHandler)
{
// Find all data blocks for desired point over given time range
m_dataBlocks = dataBlockAllocationTable.FindDataBlocks(historianID, startTime, endTime, false);
m_startTime = startTime;
m_endTime = endTime;
m_historianID = historianID;
m_dataReadExceptionHandler = dataReadExceptionHandler;
}
/// <summary>
/// Closes the <see cref="ArchiveFile"/> if it <see cref="IsOpen"/>.
/// </summary>
public void Close()
{
if (IsOpen)
{
// Abort any asynchronous processing.
m_rolloverPreparationThread.Abort();
m_buildHistoricFileListThread.Abort();
// Stop checking allocated data blocks for activity.
m_conserveMemoryTimer.Stop();
// Stop the historic and out-of-sequence data queues.
m_historicDataQueue.Stop();
m_outOfSequenceDataQueue.Stop();
// Dispose the underlying file stream object.
m_fat = null;
if (m_fileStream != null)
{
lock (m_fileStream)
{
m_fileStream.Dispose();
}
m_fileStream = null;
}
if (m_dataBlocks != null)
{
lock (m_dataBlocks)
{
m_dataBlocks.Clear();
}
m_dataBlocks = null;
}
// Stop watching for historic archive files.
m_currentLocationFileWatcher.EnableRaisingEvents = false;
m_offloadLocationFileWatcher.EnableRaisingEvents = false;
// Clear the list of historic archive files.
if (m_historicArchiveFiles != null)
{
lock (m_historicArchiveFiles)
{
m_historicArchiveFiles.Clear();
}
m_historicArchiveFiles = null;
}
}
}
/// <summary>
/// Opens the <see cref="ArchiveFile"/> for use.
/// </summary>
/// <exception cref="InvalidOperationException">One or all of the <see cref="StateFile"/>, <see cref="IntercomFile"/> or <see cref="MetadataFile"/> properties are not set.</exception>
public void Open()
{
if (!IsOpen)
{
// Check for the existance of dependencies.
if (m_stateFile == null || m_intercomFile == null | m_metadataFile == null)
throw (new InvalidOperationException("One or more of the dependency files are not specified."));
// Validate file type against its name.
m_fileName = m_fileName.ToLower();
if (Path.GetExtension(m_fileName) == StandbyFileExtension)
m_fileType = ArchiveFileType.Standby;
else if (Regex.IsMatch(m_fileName, string.Format(".+_.+_to_.+\\{0}$", FileExtension)))
m_fileType = ArchiveFileType.Historic;
else
m_fileType = ArchiveFileType.Active;
// Get the absolute path for the file name.
m_fileName = FilePath.GetAbsolutePath(m_fileName);
// Create the directory if it does not exist.
if (!Directory.Exists(FilePath.GetDirectoryName(m_fileName)))
Directory.CreateDirectory(FilePath.GetDirectoryName(m_fileName));
if (File.Exists(m_fileName))
{
// File has been created already, so we just need to read it.
m_fileStream = new FileStream(m_fileName, FileMode.Open, m_fileAccessMode, FileShare.ReadWrite);
m_fat = new ArchiveFileAllocationTable(this);
}
else
{
// File does not exist, so we have to create it and initialize it.
m_fileStream = new FileStream(m_fileName, FileMode.Create, FileAccess.ReadWrite, FileShare.ReadWrite);
m_fat = new ArchiveFileAllocationTable(this);
m_fat.Save();
}
// Don't proceed further for standby and historic files.
if (m_fileType != ArchiveFileType.Active)
return;
// Start internal process queues.
m_historicDataQueue.Start();
m_outOfSequenceDataQueue.Start();
// Open state file if closed.
if (!m_stateFile.IsOpen)
m_stateFile.Open();
//Open intercom file if closed.
if (!m_intercomFile.IsOpen)
m_intercomFile.Open();
// Open metadata file if closed.
if (!m_metadataFile.IsOpen)
m_metadataFile.Open();
// Create data block lookup list.
if (m_stateFile.RecordsInMemory > 0)
m_dataBlocks = new List<ArchiveDataBlock>(new ArchiveDataBlock[m_stateFile.RecordsInMemory]);
else
m_dataBlocks = new List<ArchiveDataBlock>(new ArchiveDataBlock[m_stateFile.RecordsOnDisk]);
// Start the memory conservation process.
if (m_conserveMemory)
m_conserveMemoryTimer.Start();
// Ensure that "rollover in progress" is not set.
IntercomRecord system = m_intercomFile.Read(1);
system.RolloverInProgress = false;
m_intercomFile.Write(1, system);
// Start preparing the list of historic files.
m_buildHistoricFileListThread = new Thread(BuildHistoricFileList);
m_buildHistoricFileListThread.Priority = ThreadPriority.Lowest;
m_buildHistoricFileListThread.Start();
// Start file watchers to monitor file system changes.
m_currentLocationFileWatcher.Filter = HistoricFilesSearchPattern;
m_currentLocationFileWatcher.Path = FilePath.GetDirectoryName(m_fileName);
m_currentLocationFileWatcher.EnableRaisingEvents = true;
if (Directory.Exists(m_fileOffloadLocation))
{
m_offloadLocationFileWatcher.Filter = HistoricFilesSearchPattern;
m_offloadLocationFileWatcher.Path = m_fileOffloadLocation;
m_offloadLocationFileWatcher.EnableRaisingEvents = true;
}
}
}
/// <summary>
/// Creates a new instance of the <see cref="TimeSortedDataPointScanner"/>.
/// </summary>
/// <param name="dataBlockAllocationTable"><see cref="ArchiveFileAllocationTable"/> for the file to be scanned.</param>
/// <param name="historianIDs">Historian ID's to scan.</param>
/// <param name="startTime">Desired start time.</param>
/// <param name="endTime">Desired end time.</param>
/// <param name="lastHistorianID">Last read historian ID, or -1 to begin scan at first ID.</param>
/// <param name="dataReadExceptionHandler">Read exception handler.</param>
public TimeSortedDataPointScanner(ArchiveFileAllocationTable dataBlockAllocationTable, IEnumerable<int> historianIDs, TimeTag startTime, TimeTag endTime, int lastHistorianID, EventHandler<EventArgs<Exception>> dataReadExceptionHandler)
{
m_dataPointScanners = new List<DataPointScanner>();
// Create data point scanners for each historian ID
foreach (int historianID in historianIDs)
{
// Start scan when last Historian ID is -1, otherwise if last historian ID is encountered, start reading at next point
if (lastHistorianID == -1)
m_dataPointScanners.Add(new DataPointScanner(dataBlockAllocationTable, historianID, startTime, endTime, dataReadExceptionHandler));
else if (lastHistorianID == historianID)
lastHistorianID = -1;
}
}
internal void CloseStream()
{
m_fat = null;
if (m_fileStream != null)
{
lock (m_fileStream)
{
m_fileStream.Flush();
m_fileStream.Close();
m_fileStream.Dispose();
}
m_fileStream = null;
}
}
internal void OpenStream()
{
if (File.Exists(m_fileName))
{
int attempts = 0;
while (true)
{
try
{
attempts++;
m_fileStream = new FileStream(m_fileName, FileMode.Open, m_fileAccessMode, FileShare.ReadWrite);
m_fat = new ArchiveFileAllocationTable(this);
break;
}
catch
{
if (attempts >= 4)
throw;
Thread.Sleep(500);
}
}
}
else
{
// File does not exist, so we have to create it and initialize it.
m_fileStream = new FileStream(m_fileName, FileMode.Create, FileAccess.ReadWrite, FileShare.ReadWrite);
m_fat = new ArchiveFileAllocationTable(this);
m_fat.Save();
// Manually call file monitoring event if file watchers are not enabled
if (!m_monitorNewArchiveFiles)
FileWatcher_Created(this, new FileSystemEventArgs(WatcherChangeTypes.Created, FilePath.GetAbsolutePath(m_fileName), FilePath.GetFileName(m_fileName)));
}
}
/// <summary>
/// Creates a new instance of the <see cref="FixedTableRegion"/>.
/// </summary>
/// <param name="parent">Reference to parent <see cref="ArchiveFileAllocationTable"/>.</param>
public FixedTableRegion(ArchiveFileAllocationTable parent)
{
m_parent = parent;
}
/// <summary>
/// Creates a new instance of the <see cref="VariableTableRegion"/>.
/// </summary>
/// <param name="parent">Reference to parent <see cref="ArchiveFileAllocationTable"/>.</param>
public VariableTableRegion(ArchiveFileAllocationTable parent)
{
m_parent = parent;
}
