//
// methods
//
/// <summary>
/// After call of this methods all existing and new requests
/// will be thrown or returned as canceled
/// </summary>
public void Cancel()
{
// Lock the data access
lock (this.dataLocker)
{
// If stete is pending
if (this.state == FileLinesCheckerState.Pending)
{
// Cancel the previous reader execution
this.linesReader.Cancel();
}
// Change the state
this.state = FileLinesCheckerState.Canceled;
// Remove reader link from roots
this.linesReader = null;
// Notify waiting threads about state changing
Monitor.PulseAll(this.dataLocker);
}
}
/// <summary>
/// Creates new LinesReader object for the storage updating
/// Sent notification to the other threads if update was not canceled
/// </summary>
/// <param name="notUsed">Not used parameter</param>
private void LoadData(Object notUsed)
{
LinesReader currentReader = new LinesReader();
// Stop previous LinesReader execution
lock (this.dataLocker)
{
if (this.state == FileLinesCheckerState.Pending)
{
// If State is pending - reader is exist
// Cancel previous reader execution
this.linesReader.Cancel();
}
else
{
this.state = FileLinesCheckerState.Pending;
}
// Save link to the current reader for cancel
this.linesReader = currentReader;
}
// Get new data from LinesReader
IDictionary newData = null;
try
{
using (Stream stream = new FileStream(this.fileName,
FileMode.Open, FileAccess.Read))
{
// Load data
newData = currentReader.Read(stream);
}
}
catch (Exception)
{
// TODO: Log exception
// An unhandled exception causes to the program crach
}
// If process was not canseled - update the data
lock (this.dataLocker)
{
// If the load process was not canceled or changed with another one
if (!currentReader.IsCanceled)
{
// If cancelation of the instance work was not requested
if (this.state != FileLinesCheckerState.Canceled)
{
// Renew the data and status
this.data = newData;
this.state = this.data == null
? FileLinesCheckerState.Error
: FileLinesCheckerState.Ready;
}
// Reader not needed more
this.linesReader = null;
// Notify other threads about data is available
Monitor.PulseAll(this.dataLocker);
}
}
}
