On Sunday, February 3, 2013 1:07:41 AM UTC-5, puzzler wrote:
>
> I just went through the process of converting my map-based program over to
> records, hoping it would improve speed. Much to my dismay, it actually
> slowed my program down substantially. With some profiling, I discovered
> that one possible explanation is that (at least in RC4) hashing of records
> is about 60x slower than their map-based counterpart.
>
> (defrecord A [x y])
> => (time (dotimes [n 10000000] (hash {:x "a" :y 3})))
> "Elapsed time: 90.631072 msecs"
> => (time (dotimes [n 10000000] (hash (A. "a" 3))))
> "Elapsed time: 5549.788311 msecs"
>
> Any thoughts about why this is the case?
>
There was a change for 1.5 to cache hasheq for maps
https://github.com/clojure/clojure/commit/d77489d3ce912c177fe288a6f399a5c1da6683db
but the same is not done for defrecords. That is why maps are so much
faster than records.
Paul
--
--
You received this message because you are subscribed to the Google
Groups "Clojure" group.
To post to this group, send email to [email protected]
Note that posts from new members are moderated - please be patient with your
first post.
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/clojure?hl=en
---
You received this message because you are subscribed to the Google Groups
"Clojure" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/groups/opt_out.
