public void SaveLatest()
{
if (_realImpl == null)
{
return;
}
RealScratchPage realImpl = GetRealImpl();
using (var w = new LineWriter(LogFile.FullName, FileMode.Append))
realImpl.SaveLatest(w.WriteLine);
File.WriteAllText(TextFile.FullName, _realImpl.Text);
_logStamp = LogFile.LastWriteTimeUtc;
_textStamp = TextFile.LastWriteTimeUtc;
}
internal RealScratchPage GetRealImpl()
{
if (_realImpl == null)
{
_realImpl = LoadRealImpl();
_phantomImpl = null;
}
else if (UnderlyingChanged())
{
RealScratchPage result = LoadRealImpl();
if (result.Text != _realImpl.Text)
{
result.Text = _realImpl.Text;
}
_realImpl = result;
}
return(_realImpl);
}
RealScratchPage LoadRealImpl()
{
// Load up a new real implementation from disk.
RealScratchPage result = null;
string text = null;
// Try getting it from the log.
try
{
if (LogFile.Exists)
{
_logStamp = LogFile.LastWriteTimeUtc;
using (var reader = new LineReader(LogFile.FullName))
result = new RealScratchPage(reader.ReadLine);
}
}
catch
{
result = null;
}
if (result == null)
{
result = new RealScratchPage();
}
// Try getting it from the text file.
if (TextFile.Exists)
{
text = File.ReadAllText(TextFile.FullName);
_textStamp = TextFile.LastWriteTimeUtc;
}
// If there's a conflict, the text file wins, but keep log history; and rewrite it.
if (text != null && result.Text != text)
{
result.Text = text;
using (var w = new LineWriter(LogFile.FullName, FileMode.Create))
result.SaveAll(w.WriteLine);
_logStamp = LogFile.LastWriteTimeUtc;
}
return(result);
}