From: "phluid61 (Matthew Kerwin)" <matthew@...>
Date: 2013-07-18T07:59:34+09:00
Subject: [ruby-core:56068] [CommonRuby - Feature #8640] Add Time#elapsed to return nanoseconds since creation


Issue #8640 has been updated by phluid61 (Matthew Kerwin).


tenderlovemaking (Aaron Patterson) wrote:
> On Wed, Jul 17, 2013 at 01:04:37PM +0900, phluid61 (Matthew Kerwin) wrote:
>  > Since the discussion has moved towards defining two separate methods {#elapsed => (float)s and #elapsed_nanoseconds => (int)ns} I do prefer a keyword argument {in: :nanoseconds}.  Sorry for wavering back and forth on the issue so noisily.
>  
>  I don't care if a method exists that has kw args, but I would not use
>  it.  The things we need to time in Rails are fairly fast (say 200ms on
>  the slow side) and happen frequently, which means that object
>  allocations matter.  A kwarg method will end up allocating a hash on
>  every call.
>  
>  If someone else wants to make a method with kwargs, I think that's
>  great, but it's not what I'm pushing for here.  My point is to reduce
>  object allocations.  :-)
>  

In that case, would #8096 be a better proposal?  Since that one doesn't even allocate a Time object.
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Feature #8640: Add Time#elapsed to return nanoseconds since creation
https://bugs.ruby-lang.org/issues/8640#change-40555

Author: tenderlovemaking (Aaron Patterson)
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 


Hi,

We time many things in Rails (and so does lots of other code), and I've found that we spend lots of time allocating and subtracting time objects.  For example:

start = Time.now
##  do stuff we want to time
finish = Time.now - start

It would be nice if we could just create one time object and grab the nanoseconds elapsed since the time object was created like so:

start = Time.now
## do stuff we want to time
finished = start.elapsed # => nanoseconds elapsed.

I've attached a patch that implements this feature.


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