On 7/21/20 7:44 AM, Ecstatic Coder wrote:
On Tuesday, 21 July 2020 at 11:01:20 UTC, drug wrote:
On 7/20/20 10:04 PM, Ecstatic Coder wrote:
I'm currently implementing a small open source backup tool (dub), and
therefore I need to accurately store the file modification SysTime in
binary format, so that I can later load this SysTime from the
snapshot file to compare it with the current file modification SysTime.
Having unfortunately not understood how to do this from the SysTime
documentation, in despair, I've tried to directly serialize the 16
bytes of the SysTime value. This worked fine until I call the
".toISOString()" on the deserialized SysTime, which inevitably
crashes the executable ;)
That is probably a bug. I serialize SysTime as long by means msgpack
for exchanging between C++ client and D server and it works pretty nice.
Ah thanks for telling me :)
The loaded byte array in the union type was indeed the same as the saved
one, so I immediately thought it was crashing because of some hidden
pointer for timezone or something which was then pointing to garbage at
reloading, causing the crash of the ".toISOString" call.
Not a bug.
8 of those 16 bytes is a pointer to the timezone, which is going to be
different on different processes.
What you should do I think is serialize the stdTime [1], and set the
time zone to whatever you want:
long serialize(SysTime st) { return st.stdTime; }
SysTime deserialize(long st) { return SysTime(st, UTC()); }
The stdTime is always stored as UTC to make math a lot easier. The time
zone is only used for display.
-Steve
[1] https://dlang.org/phobos/std_datetime_systime.html#.SysTime.stdTime
