/// <summary>
/// <see cref="IRepositoryReader.RemoveFolder"/>
/// </summary>
/// <exception cref="ObjectDisposedException">
/// The reader has been disposed.
/// </exception>
public void RemoveFolder(IRepositoryFolder folder)
{
CheckNotDisposed();
Util.Check.DoRequireArgumentNotNull(folder, "folder");
Exceptions.DifferentRepositoriesExceptionHelper.Check(folder.Repository, Repository);
RepositoryFolderReader reader = GetExistingReader(folder.FolderKey);
Util.Check.DoRequire(reader != null, "The folder is not being read by the reader");
_position.Remove(reader.Position);
reader.Unload();
bool topReaderRemoved = this.HasData && TopReader == reader;
bool success = !(!_exhaustedReaders.Remove(reader) && !_offlineQueue.Remove(reader) && !_onlineQueue.Remove(reader));
Util.Check.Ensure(success, "Internal error: reader not found.");
success = _readers.Remove(folder.FolderKey);
Util.Check.Ensure(success);
if (topReaderRemoved)
{
SyncOfflineQueueForReading();
}
Invariant();
}
/// <summary>
/// Initiate reading from the <paramref name="reader"/>.
/// It must not be in any of the 2 queues (online, offline) or exhausted list.
/// If the file contains data since <paramref name="seekTime"/> the reader will
/// be placed into offline queue. Otherwise it will go into exhausted readers list.
/// </summary>
/// <param name="reader">
/// Reader to initiate. It must not be in any of the 2 queues (online, offline) or exhausted list.
/// </param>
/// <param name="position">
/// Position to start reading from.
/// </param>
/// <remarks>
/// The method ensures that currently loaded reader's data is unloaded first.
/// Seeking is done lazily - all go to offline queue and loaded immediately
/// before reading.
/// </remarks>
private void SeekFolderReader(RepositoryFolderReader reader, IFolderReadingPosition position)
{
Check.RequireArgumentNotNull(position, "position");
Check.RequireArgumentNotNull(reader, "reader");
Check.Require(!_offlineQueue.Contains(reader) && !_exhaustedReaders.Contains(reader) && !_onlineQueue.Contains(reader));
reader.Unload();
reader.SeekDataFile(position);
AddPositionedOfflineReaderToAQueue(reader);
// as reader.Position is singleton, changes to the reader's position do not require modifying _position
_position.SetFolderPosition(reader.Position);
}
/// <summary>
/// Add the specified reader to the offline queue
/// </summary>
/// <param name="reader">
/// The reader to add. Its <see cref="RepositoryFolderReader.NextFileFound"/>
/// must equal <see langword="true"/>.
/// </param>
private void AddReaderToOfflineQueue(RepositoryFolderReader reader)
{
Util.Check.Require(reader.NextFileFound, "Internal error: reader unsuitable for offline queue");
// free memory
reader.Unload();
LinkedListNode <RepositoryFolderReader> predecessor = null;
if (_offlineQueue.Count > 0)
{
predecessor = FindPredecessorInQueue(_offlineQueue.First, reader, _offlineReaderComparer);
}
if (null == predecessor)
{
_offlineQueue.AddFirst(reader);
}
else
{
_offlineQueue.AddAfter(predecessor, reader);
}
}
private void AddToExhaustedImpl(RepositoryFolderReader reader)
{
reader.Unload();
_exhaustedReaders.AddLast(reader);
}