public RollingFileReader(string baseFileName, IFilePositionStore store, ReadBehaviour readBehaviour)
{
//TODO UNCs are not allowed
_store = store;
BaseFileName = baseFileName;
switch (readBehaviour)
{
case ReadBehaviour.FromBeginning:
_position = new FilePosition(new FileId(baseFileName, DateTime.MinValue), 0);
break;
case ReadBehaviour.FromWhereLeft:
_position = _store.GetPosition(baseFileName);
if (_position == null)
{
_position = new FilePosition(new FileId(baseFileName, DateTime.MinValue), 0);
}
break;
case ReadBehaviour.FromCurrentPos:
var fileInfo = new FileInfo(baseFileName); //TODO what if not there??
var fileId = new FileId(baseFileName, fileInfo.LastWriteTimeUtc);
long pos = fileInfo.Length;
_position = new FilePosition(fileId, pos);
break;
default:
throw new NotSupportedException("Unsupported ReadBehaviour");
}
FileStream = OpenFileStream(_position);
}
public void RollBack()
{
_position = _store.GetPosition(_position.FileId.BaseFileName);
//TODO reopen stream - we could have moved to a new file.
}
