Thanks for all the helpful advice. I may consider rewriting key portions in Java if performance becomes an issue.
Travis On May 14, 12:10 pm, David Nolen <[email protected]> wrote: > If you're going to do that you're going to need to create a let binding > which type-hints coll to bytes in your byte-array-contains? If you're going > to be doing this a lot in your code I'd recommend making a helper class in > Java. loop/recur is fast, but for absolute speed, you just can't beat > putting your tight loops in Java. > > On Thu, May 14, 2009 at 12:00 PM, tmountain <[email protected]> wrote: > > > NM, huge difference in performance even with the cast. > > > Old version: > > > (time (dotimes [_ 1000] (byte-array-contains? header 0xFE))) > > "Elapsed time: 337.312 msecs" > > > New version: > > > (time (dotimes [_ 1000] (byte-array-contains? header 0xFE))) > > "Elapsed time: 4.278 msecs" > > > On that note, is there a native way to check whether a byte array > > contains a given value? The contains? function seems to indicate > > whether a given index exists in the array rather than inspecting the > > actual value? My best stab at the moment is as follows: > > > (defn byte-array-contains? [coll key] > > "scans a byte array for a given value" > > (loop [i 0] > > (if (< i (count coll)) > > (if (== (int (byte key)) (int (byte (aget coll i)))) > > true > > (recur (inc i)))))) > > > Travis > > > On May 14, 11:40 am, tmountain <[email protected]> wrote: > > > If that's the case, would I even get a performance increase, or would > > > the cast overhead cost more than the implicit reflection? > > > > On May 14, 11:32 am, David Nolen <[email protected]> wrote: > > > > > This baffled me as well. You need to cast to int. > > > > > On Thu, May 14, 2009 at 11:22 AM, tmountain <[email protected]> > > wrote: > > > > > > I'm trying to optimize some code I've written, and I have set warn on > > > > > reflection as advised. I'm having a hard time getting a simple > > > > > statement to avoid reflection. > > > > > > user=> (== (byte 0x1) (byte 0x1)) > > > > > Reflection warning, line: 33 - call to equiv can't be resolved. > > > > > > Can you use type hints on primitive types? I've tried obvious stuff > > > > > like: > > > > > > user=> (== #^byte (byte 0x1) #^byte (byte 0x1)) > > > > > Reflection warning, line: 4 - call to equiv can't be resolved. > > > > > > and other variations without success. > > > > > > Thanks, > > > > > Travis --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to [email protected] 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 -~----------~----~----~----~------~----~------~--~---
