Re: FILETIME <-> Ada.Real_Time.Time conversions

["Steve Doiel" <nospam_steved94@attbi.com>]

> >Also note: it may not be possible (read probably isn't) to represent all
> >values of FILETIME as a Ada.Real_Time.Time value since the size of the
> >values may differ.  As I recall the resolution of time in Ada.Real_Time
is
> >not specified, but a minimum resolution and range is.
>
> We can definitely live with smaller range and/or precision. The real
> problem is that there is no correlation between epoch of
> Ada.Real_Time.Split and UTC.
>
> Regards,
> Dmitry Kazakov

Have you considered defining your own epoch in terms of both times?

You can determine the FILETIME value for your epoch using
SystemTimeToFileTime.  I'll call this file_time_epoch.  You only have to do
this once, then you can define the value as a program constant.

You can determine the Real_Time.Time value for your epoch using
Ada.Calendar.Time_Of.  I'll call this real_time_epoch.

To obtain a Real_Time.Time value from a subsequent FILETIME values use:

  real_time_value := real_time_epoch
                              + Ada.Real_Time.Nanoseconds( Integer(
file_time_value - file_time_epoch ) );

I'm sure you'll have to mess with the types to get things working, but I
think this will get you there.

SteveD