internal void MakePrivateCopyOfUndoRedo()
{
// Data in the actions may reference a file buffer that
// can become invalid (eg after saving a file)
// Copy the data to private in-memory buffers to avoid data corruption
// and crashes...
//
if (Preferences.Instance["Undo.KeepAfterSave"] == "Never")
{
undoDeque.Clear();
redoDeque.Clear();
return;
}
if (Preferences.Instance["Undo.KeepAfterSave"] == "Always")
{
foreach (ByteBufferAction action in undoDeque)
{
action.MakePrivateCopyOfData();
}
foreach (ByteBufferAction action in redoDeque)
{
action.MakePrivateCopyOfData();
}
return;
}
// if Preferences.Instance["Undo.KeepAfterSave"] == "Memory"
// drop the undo and redo actions that don't fit into memory (and all actions
// after them in the Deques).
Deque <ByteBufferAction> newUndoDeque = new Deque <ByteBufferAction>();
Deque <ByteBufferAction> newRedoDeque = new Deque <ByteBufferAction>();
foreach (ByteBufferAction action in undoDeque)
{
long freeMem = long.MaxValue;
try {
freeMem = Portable.GetAvailableMemory();
}
catch (NotImplementedException) {}
if (freeMem < action.GetPrivateCopySize())
{
break;
}
action.MakePrivateCopyOfData();
newUndoDeque.AddEnd(action);
}
foreach (ByteBufferAction action in redoDeque)
{
long freeMem = long.MaxValue;
try {
freeMem = Portable.GetAvailableMemory();
}
catch (NotImplementedException) {}
if (freeMem < action.GetPrivateCopySize())
{
break;
}
action.MakePrivateCopyOfData();
newRedoDeque.AddEnd(action);
}
undoDeque.Clear();
redoDeque.Clear();
undoDeque = newUndoDeque;
redoDeque = newRedoDeque;
}