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digitalmars.D.learn - Converting Duration to TickDuration

reply "Vladimir Panteleev" <vladimir thecybershadow.net> writes:
The simplest way I found is:  
TickDuration.from!"hnsecs"(duration.total!"hnsecs")

Is there a simpler way?

-- 
Best regards,
  Vladimir                            mailto:vladimir thecybershadow.net
Sep 12 2011
next sibling parent reply "Jonathan M Davis" <jmdavisProg gmx.com> writes:
On Tuesday, September 13, 2011 04:32:28 Vladimir Panteleev wrote:

 The simplest way I found is:
 TickDuration.from!"hnsecs"(duration.total!"hnsecs")
 
 Is there a simpler way?


I don't believe so. A TickDuration can be cast (or use std.conv.to) to convert 
to a Duration, but there is no cast in the opposite direction. One could be 
added (and perhaps it should be), but I do find it a bit odd to convert from 
Duration to TickDuration. Usually, you'd get a TickDuration from timing stuff 
(like benchmarking or some other type of stopwatch functionality), and I would 
expect creating TickDurations in other ways to be fairly rare. What are you 
doing that you want to create a TickDuration from a Duration?

- Jonathan M Davis
Sep 12 2011
parent reply "Vladimir Panteleev" <vladimir thecybershadow.net> writes:
On Tue, 13 Sep 2011 05:01:31 +0300, Jonathan M Davis <jmdavisProg gmx.com>  
wrote:


 What are you doing that you want to create a TickDuration from a  
 Duration?


On the one side, I have a module for running scheduled events. Event  
timing is specified using a TickDuration, indicating the time interval  
after which to run the event.

On the other side, I have an application which replays an event log from a  
file. Events are timestamped in stdTime format, and are stored in SysTime  
instances. Subtracting one SysTime instance from another returns a  
Duration.

-- 
Best regards,
  Vladimir                            mailto:vladimir thecybershadow.net
Sep 12 2011
parent reply "Jonathan M Davis" <jmdavisProg gmx.com> writes:
On Tuesday, September 13, 2011 05:13:02 Vladimir Panteleev wrote:

 On Tue, 13 Sep 2011 05:01:31 +0300, Jonathan M Davis <jmdavisProg gmx.com>
 
 wrote:

 What are you doing that you want to create a TickDuration from a
 Duration?


 
 On the one side, I have a module for running scheduled events. Event
 timing is specified using a TickDuration, indicating the time interval
 after which to run the event.
 
 On the other side, I have an application which replays an event log from a
 file. Events are timestamped in stdTime format, and are stored in SysTime
 instances. Subtracting one SysTime instance from another returns a
 Duration.


Personally, I'd just Duration far those and not TickDuration. Duration is just 
as precise (if not more precise) than TickDuration as long as the system ticks 
aren't less than 1 hnsec apart. TickDuration is useful in that it gives you 
timing in clock ticks if you need it (e.g. if the system clocks ticks were 
faster than 1 ever 1 hnsecs), but in the general case, it doesn't buy you 
anything over Duration, and I don't see why it would in your case either. 
Maybe something in how you're doing events?

- Jonathan M Davis
Sep 12 2011
parent reply "Vladimir Panteleev" <vladimir thecybershadow.net> writes:
On Tue, 13 Sep 2011 06:27:44 +0300, Jonathan M Davis <jmdavisProg gmx.com>  
wrote:


 Personally, I'd just Duration far those and not TickDuration. Duration  
 is just
 as precise (if not more precise) than TickDuration as long as the system  
 ticks
 aren't less than 1 hnsec apart. TickDuration is useful in that it gives  
 you
 timing in clock ticks if you need it (e.g. if the system clocks ticks  
 were
 faster than 1 ever 1 hnsecs), but in the general case, it doesn't buy you
 anything over Duration, and I don't see why it would in your case either.
 Maybe something in how you're doing events?


Well, TickDuration.currSystemTick() returns a TickDuration, so I went with  
that all across. I'll be needing to do some conversions at one point or  
another, though optimally it'd happen when creating events, and not when  
processing them, as that would have less total overhead.

-- 
Best regards,
  Vladimir                            mailto:vladimir thecybershadow.net
Sep 13 2011
parent Jonathan M Davis <jmdavisProg gmx.com> writes:
On Tuesday, September 13, 2011 15:45:27 Vladimir Panteleev wrote:

 On Tue, 13 Sep 2011 06:27:44 +0300, Jonathan M Davis <jmdavisProg gmx.com>
 
 wrote:

 Personally, I'd just Duration far those and not TickDuration. Duration
 is just
 as precise (if not more precise) than TickDuration as long as the system
 ticks
 aren't less than 1 hnsec apart. TickDuration is useful in that it gives
 you
 timing in clock ticks if you need it (e.g. if the system clocks ticks
 were
 faster than 1 ever 1 hnsecs), but in the general case, it doesn't buy
 you
 anything over Duration, and I don't see why it would in your case
 either.
 Maybe something in how you're doing events?


 
 Well, TickDuration.currSystemTick() returns a TickDuration, so I went with
 that all across. I'll be needing to do some conversions at one point or
 another, though optimally it'd happen when creating events, and not when
 processing them, as that would have less total overhead.


That makes some sense. The cast probably should be added to Duration anyway, 
even if the need is somewhat of an abnormality. And maybe such conversions 
will end up being more common than I would have thought anyway.

- Jonathan M Davis
Sep 13 2011
prev sibling parent Jonathan M Davis <jmdavisProg gmx.com> writes:
On Tuesday, September 13, 2011 04:32:28 Vladimir Panteleev wrote:

 The simplest way I found is:
 TickDuration.from!"hnsecs"(duration.total!"hnsecs")
 
 Is there a simpler way?


There's now a pull request which adds opCast to Duration which casts to 
TickDuration: https://github.com/D-Programming-Language/druntime/pull/73

- Jonathan M Davis
Sep 18 2011